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  1. NERC Presentation: Accommodating High Levels of Variable Generation...

    Energy Savers [EERE]

    American Electric Reliability Corporation (NERC): Reliability Considerations from the Integration of Smart Grid High-Energy, Low-Frequency Risk to the North American Bulk Power...

  2. Transmission Vegetation Management NERC Standard FAC-003-2 Technical...

    Open Energy Info (EERE)

    Transmission Vegetation Management NERC Standard FAC-003-2 Technical Reference Jump to: navigation, search OpenEI Reference LibraryAdd to library PermittingRegulatory Guidance -...

  3. USING NERC SCIENCE Welcome to the latest edition of the Natural Environment Research Council (NERC)

    E-Print Network [OSTI]

    Williams, Paul

    USING NERC SCIENCE March 2009 Welcome to the latest edition of the Natural Environment Research. The results will show how the UK can meet its goal to cut greenhouse gas emissions by 80% by 2050 while dealing with anxieties about energy security. The two year project has involved a unique whole systems

  4. NercEnergy, Author at Nercenergy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformationJessework usesofPublications TheScience4.21 4.43EnergyAuthor: NercEnergy

  5. A sub-mm imaging survey of ultracompact HII regions

    E-Print Network [OSTI]

    M. A. Thompson; J. Hatchell; G. H. Macdonald; T. J. Millar

    2001-12-19

    We present the preliminary results of a sub-mm imaging survey of ultracompact HII regions, conducted with the SCUBA bolometer array on JCMT.

  6. NERC All rights reserved Differentiating earthquake tsunamis from other

    E-Print Network [OSTI]

    Kirby, James T.

    © NERC All rights reserved Differentiating earthquake tsunamis from other sources; how do we tell and colleagues, co-authors on SMFs and the Japan 2011 tsunami, it's an update, · New marine data presented, · The Japan event raises questions on our use of established methodologies ­ such as tsunami wave form

  7. Property:EIA/861/NercSerc | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History ViewMayo,AltFuelVehicle2 Jump to: navigation, search This is a property of typeNercSerc Jump to:

  8. Property:EIA/861/NercWecc | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History ViewMayo,AltFuelVehicle2 Jump to: navigation, search This is a property of typeNercSerc Jump

  9. Property:EIA/861/NercFrcc | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to: navigation, search PropertyIsoOther Jump to: navigation, searchNercFrcc

  10. Property:EIA/861/NercRfc | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to: navigation, search PropertyIsoOther Jump to: navigation,NercRfc Jump to:

  11. Property:EIA/861/NercSpp | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to: navigation, search PropertyIsoOther Jump to: navigation,NercRfc Jump

  12. Regional Interagency Steering GIS Sub-Committee for FEMA's Region II Caribbean Area Division

    E-Print Network [OSTI]

    Gilbes, Fernando

    Regional Interagency Steering GIS Sub-Committee for FEMA's Region II Caribbean Area Division Jimmy Committee (RISC) consists of an interagency group where GIS users from State, Federal and Educational and download GIS data shared by participants. This effort stems from past experiences where GIS data needed

  13. WRF-Chem model predictions of the regional impacts of N<sub>2sub>O>5sub> heterogeneous processes on night-time chemistry over north-western Europe

    SciTech Connect (OSTI)

    Lowe, Douglas; Archer-Nicholls, Scott; Morgan, Will; Allan, James D.; Utembe, Steve; Ouyang, Bin; Aruffo, Eleonora; Le Breton, Michael; Zaveri, Rahul A.; di Carlo, Piero; Percival, Carl; Coe, H.; Jones, Roderic L.; McFiggans, Gordon

    2015-01-01

    Chemical modelling studies have been conducted over north-western Europe in summer conditions, showing that night-time dinitrogen pentoxide (N<sub>2sub>O>5sub>) heterogeneous reactive uptake is important regionally in modulating particulate nitrate and has a~modest influence on oxidative chemistry. Results from Weather Research and Forecasting model with Chemistry (WRF-Chem) model simulations, run with a detailed volatile organic compound (VOC) gas-phase chemistry scheme and the Model for Simulating Aerosol Interactions and Chemistry (MOSAIC) sectional aerosol scheme, were compared with a series of airborne gas and particulate measurements made over the UK in July 2010. Modelled mixing ratios of key gas-phase species were reasonably accurate (correlations with measurements of 0.7–0.9 for NO<sub>2sub> and O<sub>3sub>). However modelled loadings of particulate species were less accurate (correlation with measurements for particulate sulfate and ammonium were between 0.0 and 0.6). Sulfate mass loadings were particularly low (modelled means of 0.5–0.7 ?g kg?1<sub>air>, compared with measurements of 1.0–1.5 ?g kg?1<sub>air>). Two flights from the campaign were used as test cases – one with low relative humidity (RH) (60–70%), the other with high RH (80–90%). N<sub>2sub>O>5sub> heterogeneous chemistry was found to not be important in the low-RH test case; but in the high-RH test case it had a strong effect and significantly improved the agreement between modelled and measured NO<sub>3sub> and N<sub>2sub>O>5sub>. When the model failed to capture atmospheric RH correctly, the modelled NO<sub>3sub> and N<sub>2sub>O>5sub> mixing ratios for these flights differed significantly from the measurements. This demonstrates that, for regional modelling which involves heterogeneous processes, it is essential to capture the ambient temperature and water vapour profiles.

    The night-time NO<sub>3sub> oxidation of VOCs across the whole region was found to be 100–300 times slower than the daytime OH oxidation of these compounds. The difference in contribution was less for alkenes (× 80) and comparable for dimethylsulfide (DMS). However the suppression of NO<sub>3sub> mixing ratios across the domain by N<sub>2sub>O>5sub> heterogeneous chemistry has only a very slight, negative, influence on this oxidative capacity. The influence on regional particulate nitrate mass loadings is stronger. Night-time N<sub>2sub>O>5sub> heterogeneous chemistry maintains the production of particulate nitrate within polluted regions: when this process is taken into consideration, the daytime peak (for the 95th percentile) of PM<sub>10sub> nitrate mass loadings remains around 5.6 ?g kg?1<sub>air>, but the night-time minimum increases from 3.5 to 4.6 ?g kg?1<sub>air>. The sustaining of higher particulate mass loadings through the night by this process improves model skill at matching measured aerosol nitrate diurnal cycles and will negatively impact on regional air quality, requiring this process to be included in regional models.

  14. (Sub-)mm interferometry in massive star-forming regions

    E-Print Network [OSTI]

    H. Beuther

    2003-08-21

    (Sub-)mm interferometry is the most favorable technique to investigate the earliest stages of massive star formation. I will outline general applications in that field and discuss results of different sub-topics (hot core chemistry and massive molecular outflows). Furthermore, recent data obtained with the Submillimeter Array will be shown to present the unique capabilities of this new instrument. Finally, I will give a short outlook on the main physical topics of massive star formation to be tackled with (sub-)mm interferometry within the next decade.

  15. Regional partnerships to sequester CO{sub 2} at near-commercial scale

    SciTech Connect (OSTI)

    NONE

    2008-07-01

    A summary of the keynote speech by Acting Deputy Secretary of Energy, Jeffrey Kupfer, is given, as well as details about new agreements on CO{sub 2} injection. These include the West Coast Regional Carbon Sequestration Partnership agreement to locate CO{sub 2} injection with a 50 mw clean energy systems plant in Kumberlina, California, and the Plains CO{sub 2} Reduction Partnership and Southeast Regional Carbon Sequestration PARTNERSHIP plans to inject CO{sub 2} derived from post combustion capture at power plants. 3 photos.

  16. Source sector and region contributions to BC and PM<sub>2.5sub> in Central Asia

    SciTech Connect (OSTI)

    Kulkarni, S.; Sobhani, N.; Miller-Schulze, J. P.; Shafer, M. M.; Schauer, J. J.; Solomon, P. A.; Saide, P. E.; Spak, S. N.; Cheng, Y. F.; Denier van der Gon, H. A. C.; Lu, Z.; Streets, D. G.; Janssens-Maenhout, G.; Wiedinmyer, C.; Lantz, J.; Artamonova, M.; Chen, B.; Imashev, S.; Sverdlik, L.; Deminter, J. T.; Adhikary, B.; D'Allura, A.; Wei, C.; Carmichael, G. R.

    2015-02-18

    Particulate matter (PM) mass concentrations, seasonal cycles, source sector, and source region contributions in Central Asia (CA) are analyzed for the period April 2008–July 2009 using the Sulfur Transport and dEposition Model (STEM) chemical transport model and modeled meteorology from the Weather Research and Forecasting (WRF) model. Predicted aerosol optical depth (AOD) values (annual mean value ~0.2) in CA vary seasonally, with lowest values in the winter. Surface PM<sub>2.5sub> concentrations (annual mean value ~10 ?g m-3) also exhibit a seasonal cycle, with peak values and largest variability in the spring/summer, and lowest values and variability in the winter (hourly values from 2 to 90 ?g m-3). Surface concentrations of black carbon (BC) (mean value ~0.1 ?g m-3) show peak values in the winter. The simulated values are compared to surface measurements of AOD as well as PM<sub>2.5sub>, PM<sub>10sub>, BC, and organic carbon (OC) mass concentrations at two regional sites in Kyrgyzstan (Lidar Station Teplokluchenka (LST) and Bishkek). The predicted values of AOD and PM mass concentrations and their seasonal cycles are fairly well captured. The carbonaceous aerosols are underpredicted in winter, and analysis suggests that the winter heating emissions are underestimated in the current inventory. Dust, from sources within and outside CA, is a significant component of the PM mass and drives the seasonal cycles of PM and AOD. On an annual basis, the power and industrial sectors are found to be the most important contributors to the anthropogenic portion of PM<sub>2.5sub>. Residential combustion and transportation are shown to be the most important sectors for BC. Biomass burning within and outside the region also contributes to elevated PM and BC concentrations. The analysis of the transport pathways and the variations in particulate matter mass and composition in CA demonstrates that this region is strategically located to characterize regional and intercontinental transport of pollutants. Aerosols at these sites are shown to reflect dust, biomass burning, and anthropogenic sources from Europe; South, East, and Central Asia; and Russia depending on the time period. Simulations for a reference 2030 emission scenario based on pollution abatement measures already committed to in current legislation show that PM<sub>2.5sub> and BC concentrations in the region increase, with BC growing more than PM<sub>2.5sub> on a relative basis. This suggests that both the health impacts and the climate warming associated with these particles may increase over the next decades unless additional control measures are taken. The importance of observations in CA to help characterize the changes that are rapidly taking place in the region are discussed.

  17. Deep in a star forming region with the VLT: looking for subJupiter mass objects

    E-Print Network [OSTI]

    Comerón, Fernando

    Deep in a star forming region with the VLT: looking for sub­Jupiter mass objects F. Comer in star forming regions should have masses in the Jupiter­Saturn range and could be detectable in deep their existence and to test the input physics and chemistry of the models. Here I report on a deep JHK survey

  18. New combination bands of N{sub 2}O-CO{sub 2}, N{sub 2}O-OCS, and N{sub 2}O-N{sub 2} complexes in the N{sub 2}O ?{sub 1} region

    SciTech Connect (OSTI)

    Rezaei, M.; Moazzen-Ahmadi, N., E-mail: ahmadi@phas.ucalgary.ca [Department of Physics and Astronomy, University of Calgary, 2500 University Drive North West, Calgary, Alberta T2N 1N4 (Canada); Michaelian, K. H. [Natural Resources Canada, CanmetENERGY, 1 Oil Patch Drive, Suite A202, Devon, Alberta T9G 1A8 (Canada)] [Natural Resources Canada, CanmetENERGY, 1 Oil Patch Drive, Suite A202, Devon, Alberta T9G 1A8 (Canada)

    2014-01-28

    Spectra of the weakly bound complexes N{sub 2}O-CO{sub 2}, N{sub 2}O-OCS, and N{sub 2}O-N{sub 2} were studied in the region of the ?{sub 1} fundamental of N{sub 2}O (?2224 cm{sup ?1}) using a tunable quantum cascade laser to probe a pulsed supersonic jet expansion with an effective rotational temperature of about 2.5 K. One new combination band was observed for each complex: a band involving an intermolecular in-plane bending mode for N{sub 2}O-N{sub 2}, a band involving the disrotation (in-plane geared bend) for of N{sub 2}O-CO{sub 2}, and a band involving the out-of-plane torsional vibration for isomer b of N{sub 2}O-OCS. Small perturbations were noted for the N{sub 2}O-OCS band. Because of the absence of theoretical prediction, the nature of the intermolecular bending mode for N{sub 2}O-N{sub 2} has not been identified. The resulting intermolecular frequencies are 34.175(1), 17.107(1), and 22.334(1) cm{sup ?1} for N{sub 2}O-CO{sub 2}, N{sub 2}O-OCS, and N{sub 2}O-N{sub 2}, respectively. In addition, the previously known fundamental band of N{sub 2}O-N{sub 2} at 2225.99 cm{sup ?1} was analyzed in improved detail. This band exhibits very weak a-type transitions which were not detected in the first infrared observation of this complex, indicating that N{sub 2}O-N{sub 2} is not exactly T-shaped. That is, the N{sub 2}O molecular axis is not exactly perpendicular to the a-inertial axis, in agreement with a previous structural determination of this complex by rotational spectroscopy.

  19. Rocky Mountain Regional CO{sub 2} Storage Capacity and Significance

    SciTech Connect (OSTI)

    Laes, Denise; Eisinger, Chris; Esser, Richard; Morgan, Craig; Rauzi, Steve; Scholle, Dana; Matthews, Vince; McPherson, Brian

    2013-08-30

    The purpose of this study includes extensive characterization of the most promising geologic CO{sub 2} storage formations on the Colorado Plateau, including estimates of maximum possible storage capacity. The primary targets of characterization and capacity analysis include the Cretaceous Dakota Formation, the Jurassic Entrada Formation and the Permian Weber Formation and their equivalents in the Colorado Plateau region. The total CO{sub 2} capacity estimates for the deep saline formations of the Colorado Plateau region range between 9.8 metric GT and 143 metric GT, depending on assumed storage efficiency, formations included, and other factors.

  20. NERC 101

    Gasoline and Diesel Fuel Update (EIA)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustments (Billion Cubic Feet) Wyoming963Residential2, 2014ProvedYear Jan Feb Mar AprCubicInfrastructure:

  1. NERC funded PhD project to start in 2013 Surface mixed layer physical/biological interactions at submesoscales

    E-Print Network [OSTI]

    Cambridge, University of

    Laboratory) A NERC-funded studentship is available from 1 October 2013 (or earlier subject to individual at Submesoscales (SMILES), is to study the impact of submesoscales on the formation rate and properties of an important water mass known as Subantarctic Mode Water (SAMW). SAMW originates at the surface in the Southern

  2. "Interconnection","NERC Regional Assesment Area"

    U.S. Energy Information Administration (EIA) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page|Monthly","10/2015","1/15/1981" ,"DataWorking17.2Residential"0 DETAILED3.491. Net Energy

  3. "Interconnection","NERC Regional Assesment Area","Summer"

    U.S. Energy Information Administration (EIA) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page|Monthly","10/2015","1/15/1981" ,"DataWorking17.2Residential"0 DETAILED3.491. Net2.

  4. "January","NERC Regional Assesment Area"

    U.S. Energy Information Administration (EIA) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page|Monthly","10/2015","1/15/1981" ,"DataWorking17.2Residential"0 DETAILED3.491. Net2.A.1.

  5. Sub-mm imaging of a proto-cluster region at z=3.09

    E-Print Network [OSTI]

    S. C. Chapman; G. F. Lewis; D. Scott; E. Richards; C. Borys; C. C. Steidel; K. L. Adelberger; A. E. Shapley

    2000-10-04

    We have used the Submillimetre Common-User Bolometer Array (SCUBA) detector on the James Clerk Maxwell Telescope (JCMT) to measure bright sub-mm emission associated with a recently discovered extensive (>100/h kpc) and highly luminous, `blob' of Ly-alpha emission at z=3.09. The blob lies within a known large overdensity of optical sources in the z=3.07-3.11 range, and is centered on a locally overdense peak within this region. The best explanation for the copious sub-mm emission is a dust obscured continuum source, which may produce the ionizing flux for the Ly-alpha cloud. Cooling gas explanations are plausible but excessively complicated, and the 450/850 micron ratio rules out a significant fraction of the signal arising from the Sunyaev-Zel'dovich increment. At least two additional ~10 mJy sub-mm detections in the SCUBA map, with a surface density significantly higher than in blank field surveys, suggests that they may be associated with the z=3.09 structure. A SCUBA `photometry' observation of a second nearby Ly-alpha blob tentatively detects a weaker sub-mm counterpart.

  6. www.planetearth.nerc.ac.uk Autumn 2014 Trout in hot water Biodiversity and big data Bioenergy's carbon footprint Sustainable drainage

    E-Print Network [OSTI]

    Brierley, Andrew

    's carbon footprint · Sustainable drainage Intothe #12;Front cover image courtesy Ben Langford About us NERC to account ­ bioenergy's carbon footprint What's the true cost of growing our fuel? 22 The science

  7. Applicability of the “Gallet equation” to the vegetation clearances of NERC Reliability Standard FAC-003-2

    SciTech Connect (OSTI)

    Kirkham, Harold

    2012-03-31

    NERC has proposed a standard to use to specify clearances between vegetation and power lines. The purpose of the rule is to reduce the probability of flashover to a calculably low level. This report was commissioned by FERC’s Office of Electrical Reliability. The scope of the study was analysis of the mathematics and documentation of the technical justification behind the application of the Gallet equation and the assumptions used in the technical reference paper

  8. A study of the daytime E-F sub 1 region ionosphere at mid-latitudes

    SciTech Connect (OSTI)

    Buonsanto, M.J. (Massachusetts Inst. of Tech., Westford (USA))

    1990-06-01

    A photochemical equilibrium daytime model is used to study the ionosphere between 110 and 180 km at mid-latitudes. The model includes the latest photoionization and photoabsorption cross sections, extreme untraviolet (EUV) fluxes in 37 wavelength bands, and all reactions believed to be important in this region. Model results are compared with (1) noon-time E layer critical frequency (foE) at Boulder and Wallops Island over a full solar cycle; (2) Millstone Hill incoherent scatter radar observations of electron density at 180 km (N{sub 180}) for a wide variety of seasons and solar geophysical conditions; (3) selected Millstone Hill incoherent scatter profiles of electron density between 110 and 180 km which included E-F{sub 1} valley minima; and (4) the ratio of the molecular ion concentration to the total ion concentration at 180 km for noon throughout the solar cycle as given by both the IRI-86 ion composition model and the semiempirical ion composition model of Oliver. Best agreement between the photochemical model documented in this paper and the observations and ion composition models is generally obtained if (1) the EUV fluxes in the photochemical model are increased by 25-30% above values derived from published reference spectra; (2) neutral densities used in the photochemical model are decreased by 25% below those given by MSIS-86 at equinox, with larger decreases in winter, and smaller or no decreases in summer. The results show that this region of the ionosphere can be modeled with reasonable success given the current state of knowledge. Modeling this region of the ionosphere is important for resolving ambiguities in true height analysis of ionograms and reduction of incoherent scatter spectra. Improved modeling requires more accurate values of aeronomical parameters, i.e., ionizing fluxes, cross sections, reaction rates, composition and temperature.

  9. Reactive power interconnection requirements for PV and wind plants : recommendations to NERC.

    SciTech Connect (OSTI)

    McDowell, Jason; Walling, Reigh; Peter, William; Von Engeln, Edi; Seymour, Eric; Nelson, Robert; Casey, Leo; Ellis, Abraham; Barker, Chris.

    2012-02-01

    Voltage on the North American bulk system is normally regulated by synchronous generators, which typically are provided with voltage schedules by transmission system operators. In the past, variable generation plants were considered very small relative to conventional generating units, and were characteristically either induction generator (wind) or line-commutated inverters (photovoltaic) that have no inherent voltage regulation capability. However, the growing level of penetration of non-traditional renewable generation - especially wind and solar - has led to the need for renewable generation to contribute more significantly to power system voltage control and reactive power capacity. Modern wind-turbine generators, and increasingly PV inverters as well, have considerable dynamic reactive power capability, which can be further enhanced with other reactive support equipment at the plant level to meet interconnection requirements. This report contains a set of recommendations to the North-America Electricity Reliability Corporation (NERC) as part of Task 1-3 (interconnection requirements) of the Integration of Variable Generation Task Force (IVGTF) work plan. The report discusses reactive capability of different generator technologies, reviews existing reactive power standards, and provides specific recommendations to improve existing interconnection standards.

  10. {beta}{sub {beta}} measurements of neutron-rich isotopes in the mass region 147{le}A{le}152

    SciTech Connect (OSTI)

    Ikuta, T.; Taniguchi, A.; Yamamoto, H.; Kawade, K. [Nagoya Univ. (Japan); Kawase, Y. [Kyoto Univ., Osaka (Japan)

    1994-12-31

    The systematic Q{sub {beta}} measurements of 14 neutron-rich nuclei in the mass region from A=147 to A=152 have been performed with an HPGe detector. Neutron-rich nuclei were mass-separated from the thermal neutron induced fission of {sup 235}U using a He-N{sub 2} mixture-jet type on-line isotope separator which has been developed at the Kyoto University Reactor (KUR-ISOL). From a {beta}-ray singles and {beta}-{gamma} coincidence measurements, the Q{sub {beta}} values of {sup 147}La, {sup 147-150}Ce, {sup 147-152}Pr, {sup 152}Nd and {sup 152}Pm have been determined. In addition, the atomic masses derived from the experimental Q{sub {beta}} values are compared with the predictions of theoretical mass calculations.

  11. Microsoft PowerPoint - NERC Reliability Standards and Mandatory Compliance Presentation to Hydro-Power Conference - June 2007.p

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines light on darkMicroorganismsnow widelySmall Ice CrystalsHighMorgantownNERC

  12. The NO{sub x} Budget trading program: a collaborative, innovative approach to solving a regional air pollution problem

    SciTech Connect (OSTI)

    Napolitano, Sam; Stevens, Gabrielle; Schreifels, Jeremy; Culligan, Kevin

    2007-11-15

    The NO{sub x} Budget Trading Program showed that regional cap-and-trade programs are adaptable to more than one pollutant, time period, and geographic scale, and can achieve compliance results similar to the Acid Rain Program. Here are 11 specific lessons that have emerged from the experience. (author)

  13. Modeling regional power transfers

    SciTech Connect (OSTI)

    Kavicky, J.A.; Veselka, T.D.

    1994-03-01

    The Spot Market Network (SMN) model was used to estimate spot market transactions and prices between various North American Electric Reliability Council (NERC) regions for summer on-peak situations. A preliminary analysis of new or proposed additions to the transmission network was performed. The effects of alternative exempt wholesale generator (EWG) options on spot market transactions and the transmission system are also studied. This paper presents the SMN regional modelling approach and summarizes simulation results. Although the paper focuses on a regional network representation, a discussion of how the SMN model was used to represent a detailed utility-level network is also presented.

  14. SIMULATION FRAMEWORK FOR REGIONAL GEOLOGIC CO{sub 2} STORAGE ALONG ARCHES PROVINCE OF MIDWESTERN UNITED STATES

    SciTech Connect (OSTI)

    Sminchak, Joel

    2012-09-30

    This report presents final technical results for the project Simulation Framework for Regional Geologic CO{sub 2} Storage Infrastructure along Arches Province of the Midwest United States. The Arches Simulation project was a three year effort designed to develop a simulation framework for regional geologic carbon dioxide (CO{sub 2}) storage infrastructure along the Arches Province through development of a geologic model and advanced reservoir simulations of large-scale CO{sub 2} storage. The project included five major technical tasks: (1) compilation of geologic, hydraulic and injection data on Mount Simon, (2) development of model framework and parameters, (3) preliminary variable density flow simulations, (4) multi-phase model runs of regional storage scenarios, and (5) implications for regional storage feasibility. The Arches Province is an informal region in northeastern Indiana, northern Kentucky, western Ohio, and southern Michigan where sedimentary rock formations form broad arch and platform structures. In the province, the Mount Simon sandstone is an appealing deep saline formation for CO{sub 2} storage because of the intersection of reservoir thickness and permeability. Many CO{sub 2} sources are located in proximity to the Arches Province, and the area is adjacent to coal fired power plants along the Ohio River Valley corridor. Geophysical well logs, rock samples, drilling logs, and geotechnical tests were evaluated for a 500,000 km{sup 2} study area centered on the Arches Province. Hydraulic parameters and historical operational information was also compiled from Mount Simon wastewater injection wells in the region. This information was integrated into a geocellular model that depicts the parameters and conditions in a numerical array. The geologic and hydraulic data were integrated into a three-dimensional grid of porosity and permeability, which are key parameters regarding fluid flow and pressure buildup due to CO{sub 2} injection. Permeability data were corrected in locations where reservoir tests have been performed in Mount Simon injection wells. The geocellular model was used to develop a series of numerical simulations designed to support CO{sub 2} storage applications in the Arches Province. Variable density fluid flow simulations were initially run to evaluate model sensitivity to input parameters. Two dimensional, multiple-phase simulations were completed to evaluate issues related to arranging injection fields in the study area. A basin-scale, multiple-phase model was developed to evaluate large scale injection effects across the region. Finally, local scale simulations were also completed with more detailed depiction of the Eau Claire formation to investigate to the potential for upward migration of CO{sub 2}. Overall, the technical work on the project concluded that injection large-scale injection may be achieved with proper field design, operation, siting, and monitoring. Records from Mount Simon injection wells were compiled, documenting more than 20 billion gallons of injection into the Mount Simon formation in the Arches Province over the past 40 years, equivalent to approximately 60 million metric tons CO2. The multi-state team effort was useful in delineating the geographic variability in the Mount Simon reservoir properties. Simulations better defined potential well fields, well field arrangement, CO{sub 2} pipeline distribution system, and operational parameters for large-scale injection in the Arches Province. Multiphase scoping level simulations suggest that injection fields with arrays of 9 to 50+ wells may be used to accommodate large injection volumes. Individual wells may need to be separated by 3 to 10 km. Injection fields may require spacing of 25 to 40 km to limit pressure and saturation front interference. Basin-scale multiple-phase simulations in STOMP reflect variability in the Mount Simon. While simulations suggest a total injection rate of 100 million metric tons per year (approximately to a 40% reduction of CO{sub 2} emissions from large point sources across the Arches Pr

  15. Electronic state spectroscopy of diiodomethane (CH{sub 2}I{sub 2}): Experimental and computational studies in the 30?000–95?000 cm{sup ?1} region

    SciTech Connect (OSTI)

    Mandal, Anuvab; Jagatap, B. N.; Singh, Param Jeet; Shastri, Aparna

    2014-05-21

    The electronic absorption spectrum of diiodomethane in the 30?000–95?000 cm{sup ?1} region is investigated using synchrotron radiation; the spectrum in the 50?000–66?500 cm{sup ?1} region is reported for the first time. The absorption bands in the 30?000–50?000 cm{sup ?1} region are attributed to valence transitions, while the vacuum ultraviolet (VUV) spectrum (50?000–95?000 cm{sup ?1}) is dominated by several Rydberg series converging to the first four ionization potentials of CH{sub 2}I{sub 2} at 9.46, 9.76, 10.21, and 10.56 eV corresponding to the removal of an electron from the outermost 3b{sub 2}, 2b{sub 1}, 1a{sub 2}, and 4a{sub 1} non-bonding orbitals, respectively. Rydberg series of ns, np, and nd type converging to each of the four ionization potentials are assigned based on a quantum defect analysis. Time dependent density functional theory calculations of excited states support the analysis and help in interpretation of the Rydberg and valence nature of observed transitions. Density functional theory calculations of the neutral and ionic ground state geometries and vibrational frequencies are used to assign the observed vibronic structure. Vibronic features accompanying the Rydberg series are mainly due to excitation of the C-I symmetric stretch (?{sub 3}) and CH{sub 2} wag (?{sub 8}) modes, with smaller contributions from the C-H symmetric stretch (?{sub 1}). UV absorption bands are assigned to low lying valence states 1{sup 1}B{sub 2}, 1{sup 1}B{sub 1}, 2{sup 1}A{sub 1}, 3{sup 1}A{sub 1}, 2{sup 1}B{sub 1}, and 2{sup 1}B{sub 2} and the unusually high underlying intensity in parts of the VUV spectrum is attributed to valence states with high oscillator strength. This is the first report of a comprehensive Rydberg series and vibronic analysis of the VUV absorption spectrum of CH{sub 2}I{sub 2} in the 50?000–85?000 cm{sup ?1} region. The VUV absorption spectrum of CD{sub 2}I{sub 2} which serves to verify and consolidate spectral assignments is also reported here for the first time.

  16. SIMULATION FRAMEWORK FOR REGIONAL GEOLOGIC CO{sub 2} STORAGE ALONG ARCHES PROVINCE OF MIDWESTERN UNITED STATES

    SciTech Connect (OSTI)

    Sminchak, Joel

    2012-09-30

    This report presents final technical results for the project Simulation Framework for Regional Geologic CO{sub 2} Storage Infrastructure along Arches Province of the Midwest United States. The Arches Simulation project was a three year effort designed to develop a simulation framework for regional geologic carbon dioxide (CO{sub 2}) storage infrastructure along the Arches Province through development of a geologic model and advanced reservoir simulations of large-scale CO{sub 2} storage. The project included five major technical tasks: (1) compilation of geologic, hydraulic and injection data on Mount Simon, (2) development of model framework and parameters, (3) preliminary variable density flow simulations, (4) multi-phase model runs of regional storage scenarios, and (5) implications for regional storage feasibility. The Arches Province is an informal region in northeastern Indiana, northern Kentucky, western Ohio, and southern Michigan where sedimentary rock formations form broad arch and platform structures. In the province, the Mount Simon sandstone is an appealing deep saline formation for CO{sub 2} storage because of the intersection of reservoir thickness and permeability. Many CO{sub 2} sources are located in proximity to the Arches Province, and the area is adjacent to coal fired power plants along the Ohio River Valley corridor. Geophysical well logs, rock samples, drilling logs, and geotechnical tests were evaluated for a 500,000 km{sup 2} study area centered on the Arches Province. Hydraulic parameters and historical operational information was also compiled from Mount Simon wastewater injection wells in the region. This information was integrated into a geocellular model that depicts the parameters and conditions in a numerical array. The geologic and hydraulic data were integrated into a three-dimensional grid of porosity and permeability, which are key parameters regarding fluid flow and pressure buildup due to CO{sub 2} injection. Permeability data were corrected in locations where reservoir tests have been performed in Mount Simon injection wells. The geocellular model was used to develop a series of numerical simulations designed to support CO2 storage applications in the Arches Province. Variable density fluid flow simulations were initially run to evaluate model sensitivity to input parameters. Two dimensional, multiple-phase simulations were completed to evaluate issues related to arranging injection fields in the study area. A basin-scale, multiple-phase model was developed to evaluate large scale injection effects across the region. Finally, local scale simulations were also completed with more detailed depiction of the Eau Claire formation to investigate to the potential for upward migration of CO2. Overall, the technical work on the project concluded that injection large-scale injection may be achieved with proper field design, operation, siting, and monitoring. Records from Mount Simon injection wells were compiled, documenting more than 20 billion gallons of injection into the Mount Simon formation in the Arches Province over the past 40 years, equivalent to approximately 60 million metric tons CO2. The multi-state team effort was useful in delineating the geographic variability in the Mount Simon reservoir properties. Simulations better defined potential well fields, well field arrangement, CO2 pipeline distribution system, and operational parameters for large-scale injection in the Arches Province. Multiphase scoping level simulations suggest that injection fields with arrays of 9 to 50+ wells may be used to accommodate large injection volumes. Individual wells may need to be separated by 3 to 10 km. Injection fields may require spacing of 25 to 40 km to limit pressure and saturation front interference. Basin-scale multiple-phase simulations in STOMP reflect variability in the Mount Simon. While simulations suggest a total injection rate of 100 million metric tons per year (approximately to a 40% reduction of CO2 emissions from large point sources across the Arches Province) may be feasible,

  17. K{sub S} Lambda Photoproduction On The Neutron Within The Resonance Region

    SciTech Connect (OSTI)

    Taylor, Charles E.; Cole, Philip L.

    2014-01-01

    We report some preliminary differential cross section results for the gammad --> K{sub S} Lambda(p) reaction using a circularly-polarized photon beam and an unpolarized LD{sub 2} target. The data was collected at the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. For this study the photon energy ranged from 1.3 to 2.53 GeV, which covers from the reaction threshold through the nucleon resonance regimes. The acceptance- and flux-corrected yields show peaks at the center-of mass energies W = 1.7 and W = 1.9 GeV. These first-time results will aid in unraveling the spectrum of non-strange excited baryons.

  18. "Interconnection","NERC Regional Assesment Area","Net Internal Demand[1] -- Winter"

    U.S. Energy Information Administration (EIA) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page|Monthly","10/2015","1/15/1981" ,"DataWorking17.2Residential"0 DETAILED3.491. Net

  19. On an improved sub-regional water resources management representation for integration into earth system models

    SciTech Connect (OSTI)

    Voisin, Nathalie; Li, Hongyi; Ward, Duane L.; Huang, Maoyi; Wigmosta, Mark S.; Leung, Lai-Yung R.

    2013-09-30

    Human influence on the hydrologic cycle includes regulation and storage, consumptive use and overall redistribution of water resources in space and time. Representing these processes is essential for applications of earth system models in hydrologic and climate predictions, as well as impact studies at regional to global scales. Emerging large-scale research reservoir models use generic operating rules that are flexible for coupling with earth system models. Those generic operating rules have been successful in reproducing the overall regulated flow at large basin scales. This study investigates the uncertainties of the reservoir models from different implementations of the generic operating rules using the complex multi-objective Columbia River Regulation System in northwestern United States as an example to understand their effects on not only regulated flow but also reservoir storage and fraction of the demand that is met. Numerical experiments are designed to test new generic operating rules that combine storage and releases targets for multi-purpose reservoirs and to compare the use of reservoir usage priorities, withdrawals vs. consumptive demand, as well as natural vs. regulated mean flow for calibrating operating rules. Overall the best performing implementation is the use of the combined priorities (flood control storage targets and irrigation release targets) operating rules calibrated with mean annual natural flow and mean monthly withdrawals. The challenge of not accounting for groundwater withdrawals, or on the contrary, assuming that all remaining demand is met through groundwater extractions, is discussed.

  20. Estimates of global, regional, and national annual CO{sub 2} emissions from fossil-fuel burning, hydraulic cement production, and gas flaring: 1950--1992

    SciTech Connect (OSTI)

    Boden, T.A.; Marland, G.; Andres, R.J.

    1995-12-01

    This document describes the compilation, content, and format of the most comprehensive C0{sub 2}-emissions database currently available. The database includes global, regional, and national annual estimates of C0{sub 2} emissions resulting from fossil-fuel burning, cement manufacturing, and gas flaring in oil fields for 1950--92 as well as the energy production, consumption, and trade data used for these estimates. The methods of Marland and Rotty (1983) are used to calculate these emission estimates. For the first time, the methods and data used to calculate CO, emissions from gas flaring are presented. This C0{sub 2}-emissions database is useful for carbon-cycle research, provides estimates of the rate at which fossil-fuel combustion has released C0{sub 2} to the atmosphere, and offers baseline estimates for those countries compiling 1990 C0{sub 2}-emissions inventories.

  1. Grain size dependent phase stabilities and presence of a monoclinic (Pm) phase in the morphotropic phase boundary region of (1?x)Bi(Mg{sub 1/2}Ti{sub 1/2})O{sub 3}-xPbTiO{sub 3} piezoceramics

    SciTech Connect (OSTI)

    Upadhyay, Ashutosh; Singh, Akhilesh Kumar E-mail: aksingh.mst@itbhu.ac.in

    2015-04-14

    Results of the room temperature structural studies on (1?x)Bi(Mg{sub 1/2}Ti{sub 1/2})O{sub 3}-xPbTiO{sub 3} ceramics using Rietveld analysis of the powder x-ray diffraction data in the composition range 0.28???x???0.45 are presented. The morphotropic phase boundary region exhibits coexistence of monoclinic (space group Pm) and tetragonal (space group P4?mm) phases in the composition range 0.33???x???0.40. The structure is nearly single phase monoclinic (space group Pm) in the composition range 0.28???x???0.32. The structure for the compositions with x???0.45 is found to be predominantly tetragonal with space group P4?mm. Rietveld refinement of the structure rules out the coexistence of rhombohedral and tetragonal phases in the morphotropic phase boundary region reported by earlier authors. The Rietveld structure analysis for the sample x?=?.35 calcined at various temperatures reveals that phase fraction of the coexisting phases in the morphotropic phase boundary region varies with grain size. The structural parameters of the two coexisting phases also change slightly with changing grain size.

  2. Solar ALMA: Observation-Based Simulations of the mm and sub-mm Emissions from Active Regions

    E-Print Network [OSTI]

    Fleishman, Gregory; Nita, Gelu

    2015-01-01

    We developed an efficient algorithm integrated in our 3D modeling tool, GX Simulator (Nita et al. 2015), allowing quick computation of the synthetic intensity and polarization maps of solar active regions (AR) in the ALMA spectral range. The algorithm analyzes the photospheric input (white light and magnetogram) to classify a given photospheric pixel to belong to a given photospheric structure. Then, a 1D chromospheric model (Fontenla et al. 2009) is added on top of each pixel, which forms a chromospheric model of the AR. Next step is computation of the mm and sub-mm emission produced from this chromosphere model. A huge advantage of this approach is that emission from any given AR can be synthesized very fast, on the order of a few minutes after the AR selection. Using the GX Simulator tool it is also possible to produce synthetic maps of the microwave (gyroresonance) and EUV emission from the same AR model and compare them with the ALMA synthetic maps and with the corresponding observed microwave and/or EUV...

  3. Modeling and Thermal Performance Evaluation of Porous Curd Layers in Sub-Cooled Boiling Region of PWRs and Effects of Sub-Cooled Nucleate Boiling on Anomalous Porous Crud Deposition on Fuel Pin Surfaces

    SciTech Connect (OSTI)

    Barclay Jones

    2005-06-27

    A significant number of current PWRs around the world are experiencing anomalous crud deposition in the sub-cooled region of the core, resulting in an axial power shift or Axial Offset Anomaly (AOA), a condition that continues to elude prediction of occurrence and thermal/neutronic performance. This creates an operational difficulty of not being able to accurately determine power safety margin. In some cases this condition has required power ''down rating'' by as much as thirty percent and the concomitant considerable loss of revenue for the utility. This study examines two aspects of the issue: thermal performance of crud layer and effect of sub-cooled nucleate boiling on the solute concentration and its influence on initiation of crud deposition/formation on fuel pin surface.

  4. Preparation and spectroscopic properties of rare-earth (RE) (RE = Sm, Eu, Tb, Dy, Tm)-activated K{sub 2}LnZr(PO{sub 4}){sub 3} (Ln = Y, La, Gd and Lu) phosphate in vacuum ultraviolet region

    SciTech Connect (OSTI)

    Zhang, Zhi-Jun; Lin, Xiao; Graduate School of Chinese Academy of Science, Beijing, 100039 ; Zhao, Jing-Tai; Zhang, Guo-Bin

    2013-02-15

    Graphical abstract: Display Omitted Highlights: ? We report the VUV spectroscopic properties of rare-earth ions in K{sub 2}LnZr(PO{sub 4}){sub 3}. ? The O{sup 2?}-Eu{sup 3+} charge transfer bands at about 220 nm have been observed. ? The 4f–5d spin-allowed and spin-forbidden transitions of Tb{sup 3+} have been observed. ? There is energy transfer between the host and rare-earth activators. -- Abstract: Rare earth (RE = Sm, Eu, Tb, Dy and Tm)-activated K{sub 2}LnZr(PO{sub 4}){sub 3} (Ln = Y, La, Gd and Lu) have been synthesized by solid-state reaction method, and their vacuum ultraviolet (VUV) excitation luminescent characteristics have been investigated. The band in the wavelength range of 130–157 nm and the other one range from 155 to 216 nm with the maximum at about 187 nm in the VUV excitation spectra of these compounds are attributed to the host lattice absorption and O–Zr charge transfer transition, respectively. The charge transfer bands (CTB) of O{sup 2?}-Sm{sup 3+}, O{sup 2?}-Dy{sup 3+} and O{sup 2?}-Tm{sup 3+}, in Sm{sup 3+}, Dy{sup 3+} and Tm{sup 3+}-activated samples, have not been obviously observed probably because the 2p electrons of oxygen are tightly bound to the zirconium ion in the host lattice. For Eu{sup 3+}-activated samples, the relatively weak O{sup 2?}-Eu{sup 3+} CTB at about 220 nm is observed. And for Tb{sup 3+}-activated samples, the bands at 223 and 258 nm are related to the 4f-5d spin-allowed and spin-forbidden transitions of Tb{sup 3+}, respectively. It is observed that there is energy transfer between the host lattice and the luminescent activators (e.g. Eu{sup 3+}, Tb{sup 3+}). From the standpoint of luminescent efficiency, color purity and chemical stability, K{sub 2}GdZr(PO{sub 4}){sub 3}:Sm{sup 3+}, Eu{sup 3+}, Tb{sup 3+} are attractive candidates for novel yellow, red, green-emitting PDP phosphors.

  5. CO{sub 2} Allowance Allocation in the Regional Greenhouse Gas Initiative and the Effect on Electricity Investors

    SciTech Connect (OSTI)

    Burtraw, Dallas; Kahn, Danny; Palmer, Karen

    2006-03-01

    The Regional Greenhouse Gas Initiative among Northeastern states is expected to lead to an increase in the price of electricity in the region and beyond. In the RGGI region, changes in the value of electricity-generating assets may be positive or negative, while changes outside the Northeast are virtually always positive. For stakeholders in the industry, the change depends on the portfolio of assets held by affected firms. (author)

  6. Conceptual Model Summary Report Simulation Framework for Regional Geologic CO{sub 2} Storage Along Arches Province of Midwestern United States

    SciTech Connect (OSTI)

    None

    2011-06-30

    A conceptual model was developed for the Arches Province that integrates geologic and hydrologic information on the Eau Claire and Mt. Simon formations into a geocellular model. The conceptual model describes the geologic setting, stratigraphy, geologic structures, hydrologic features, and distribution of key hydraulic parameters. The conceptual model is focused on the Mt. Simon sandstone and Eau Claire formations. The geocellular model depicts the parameters and conditions in a numerical array that may be imported into the numerical simulations of carbon dioxide (CO{sub 2}) storage. Geophysical well logs, rock samples, drilling logs, geotechnical test results, and reservoir tests were evaluated for a 500,000 km{sup 2} study area centered on the Arches Province. The geologic and hydraulic data were integrated into a three-dimensional (3D) grid of porosity and permeability, which are key parameters regarding fluid flow and pressure buildup due to CO{sub 2} injection. Permeability data were corrected in locations where reservoir tests have been performed in Mt. Simon injection wells. The final geocellular model covers an area of 600 km by 600 km centered on the Arches Province. The geocellular model includes a total of 24,500,000 cells representing estimated porosity and permeability distribution. CO{sub 2} injection scenarios were developed for on-site and regional injection fields at rates of 70 to 140 million metric tons per year.

  7. Insight into the Atomic Structure of High-Voltage Spinel LiNi<sub>0.5sub>Mn>1.5sub>O>4sub> Cathode Material in the First Cycle

    SciTech Connect (OSTI)

    Huang, Xuejie; Yu, Xiqian; Lin, Mingxiang; Ben, Liubin; Sun, Yang; Wang, Hao; Yang, Zhenzhong; Gu, Lin; Yang, Xiao -Qing; Zhao, Haofei; Yu, Richeng; Armand, Michel

    2014-12-22

    Application of high-voltage spinel LiNi<sub>0.5sub>Mn>1.5sub>O>4sub> cathode material is the closest and the most realistic approach to meeting the midterm goal of lithium-ion batteries for electric vehicles (EVs) and plug-in hybrid electric vehicles (HEVs). However, this application has been hampered by long-standing issues, such as capacity degradation and poor first-cycle Coulombic efficiency of LiNi<sub>0.5sub>Mn>1.5sub>O>4sub> cathode material. Although it is well-known that the structure of LiNi<sub>0.5sub>Mn>1.5sub>O>4sub> into which Li ions are reversibly intercalated plays a critical role in the above issues, performance degradation related to structural changes, particularly in the first cycle, are not fully understood. Here, we report detailed investigations of local atomic-level and average structure of LiNi<sub>0.5sub>Mn>1.5sub>O>4sub> during first cycle (3.5–4.9 V) at room temperature. We observed two types of local atomic-level migration of transition metals (TM) ions in the cathode of a well-prepared LiNi<sub>0.5sub>Mn>1.5sub>O>4sub>//Li half-cell during first charge via an aberration-corrected scanning transmission electron microscopy (STEM). Surface regions (~2 nm) of the cycled LiNi<sub>0.5sub>Mn>1.5sub>O>4sub> particles show migration of TM ions into tetrahedral Li sites to form a Mn<sub>3sub>O>4sub>-like structure. However, subsurface regions of the cycled particles exhibit migration of TM ions into empty octahedral sites to form a rocksalt-like structure. The migration of these TM ions are closely related to dissolution of Ni/Mn ions and building-up of charge transfer impedance, which contribute significantly to the capacity degradation and the poor first-cycle Coulombic efficiency of spinel LiNi<sub>0.5sub>Mn>1.5sub>O>4sub> cathode material. Accordingly, we provide suggestions of effective stabilization of LiNi<sub>0.5sub>Mn>1.5sub>O>4sub> structure to obtain better electrochemical performance.

  8. Synthesis, structure, and physical properties of [Sm(C{sub 6}NO{sub 2}H{sub 5}){sub 3}(H{sub 2}O){sub 2}]{sub 2n}.(H{sub 5}O{sub 2}){sub n}(ZnCl{sub 5}){sub n}(ZnCl{sub 4}){sub 2n}.(H{sub 2}O){sub 2n} with unprecedented ZnCl{sub 5}{sup 3-} species

    SciTech Connect (OSTI)

    Xie Yiming Chen Wentong; Wu Jihuai

    2008-08-15

    A novel bimetallic 4f-3d metal-isonicotinic acid inorganic-organic hybrid complex [Sm(C{sub 6}NO{sub 2}H{sub 5}){sub 3}(H{sub 2}O){sub 2}]{sub 2n}.(H{sub 5}O{sub 2}){sub n}(ZnCl{sub 5}){sub n}(ZnCl{sub 4}){sub 2n}.(H{sub 2}O){sub 2n} (1) has been synthesized via hydrothermal reaction and structurally characterized by single-crystal X-ray diffraction. Complex 1 is characteristic of a one-dimensional polycationic chain-like structure and unprecedented ZnCl{sub 5}{sup 3-} species. Photoluminescent investigation reveals that the title complex displays interesting emissions in a wide region. Optical absorption spectra of 1 reveal the presence of an optical gap of 3.59 eV. - Graphical abstract: A novel bimetallic 4f-3d metal-isonicotinic acid inorganic-organic hybrid complex was synthesized. It is characteristic of a one-dimensional polycationic chain-like structure. Photoluminescent investigation reveals that the title complex displays interesting emissions in a wide region. Optical absorption spectra of 1 reveal the presence of a wide optical bandgap.

  9. Nercenergy » NercEnergy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shinesSolar Photovoltaic(MillionNature and Origin What Certificates Should My

  10. Specific heat investigation for line nodes in heavily overdoped Ba<sub>1-xsub>KxFe>2sub>As>2sub>

    SciTech Connect (OSTI)

    Kim, J. S.; Stewart, G. R.; Liu, Yong; Lograsso, Thomas A.

    2015-06-10

    Previous research has found that the pairing symmetry in the iron-based superconductor Ba<sub>1-xsub>KxFe>2sub>As>2sub> changes from nodeless s-wave near optimally doped, x?0.4-0.55 and T<sub>c>>30 K, to nodal (either d-wave or s-wave) at the pure endpoint, x=1 and T<sub>c><4 K. Intense theoretical interest has been focused on this possibility of changing pairing symmetry, where in the transition region both order parameters would be present and time reversal symmetry would be broken. Here we report specific heat measurements in zero and applied magnetic fields down to 0.4 K of three individual single crystals, free of low temperature magnetic anomalies, of heavily overdoped Ba<sub>1-xsub>KxFe>2sub>As>2sub>, x= 0.91, 0.88, and 0.81. The values for T<sub>c>mid are 5.6, 7.2 and 13 K and for H<sub>c2sub>? 4.5, 6, and 20 T respectively. Furthermore, the data can be analyzed in a two gap scenario, ?<sub>2sub>/?>1sub> ? 4, with the magnetic field dependence of ? (=C/T as T?0) showing an anisotropic ‘S-shaped’ behavior vs H, with the suppression of the lower gap by 1 T and ? ? H1/2 overall. Although such a non-linear ? vs H is consistent with deep minima or nodes in the gap structure, it is not clear evidence for one, or both, of the gaps being nodal in these overdoped samples. Thus, following the established theoretical analysis of the specific heat of d-wave cuprate superconductors containing line nodes, we present the specific heat normalized by H1/2 plotted vs T/H1/2 of these heavily overdoped Ba<sub>1-xsub>KxFe>2sub>As>2sub> samples which – thanks to the absence of magnetic impurities in our sample - convincingly shows the expected scaling for line node behavior for the larger gap for all three compositions. There is however no clear observation of the nodal behavior C ??T2 in zero field at low temperatures, with ? ? 2 mJ/molK3 being consistent with the data. Together with the scaling, this leaves open the possibility of extreme anisotropy in a nodeless larger gap, ?<sub>2sub>, such that the scaling works for fields above 0.25 – 0.5 T (0.2 – 0.4 K in temperature units), where this an estimate for the size of the deep minima in the ?<sub>2sub> ~ 20-25 K gap. Furthermore, the location of the change from nodeless?nodal gaps between optimally doped and heavily overdoped Ba<sub>1-xsub>KxFe>2sub>As>2sub> based on the present work may be closer to the KFe<sub>2sub>As>2sub> endpoint than x=0.91.

  11. CO{sub 2} Sequestration Capacity and Associated Aspects of the Most Promising Geologic Formations in the Rocky Mountain Region: Local-Scale Analyses

    SciTech Connect (OSTI)

    Laes, Denise; Eisinger, Chris; Morgan, Craig; Rauzi, Steve; Scholle, Dana; Scott, Phyllis; Lee, Si-Yong; Zaluski, Wade; Esser, Richard; Matthews, Vince; McPherson, Brian

    2013-07-30

    The purpose of this report is to provide a summary of individual local-­?scale CCS site characterization studies conducted in Colorado, New Mexico and Utah. These site-­? specific characterization analyses were performed as part of the “Characterization of Most Promising Sequestration Formations in the Rocky Mountain Region” (RMCCS) project. The primary objective of these local-­?scale analyses is to provide a basis for regional-­?scale characterization efforts within each state. Specifically, limits on time and funding will typically inhibit CCS projects from conducting high-­? resolution characterization of a state-­?sized region, but smaller (< 10,000 km{sup 2}) site analyses are usually possible, and such can provide insight regarding limiting factors for the regional-­?scale geology. For the RMCCS project, the outcomes of these local-­?scale studies provide a starting point for future local-­?scale site characterization efforts in the Rocky Mountain region.

  12. Evidence for tt?? Production and Measurement of (?<sub> tt?sub>)?/(?tt?>)

    SciTech Connect (OSTI)

    Aaltonen, T; Alvarez Gonzalez, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Appel, J A; Apresyan, A; Arisawa, T

    2011-08-31

    Using data corresponding to 6.0 fb-1 of pp? collisions at ?s = 1.96 TeV collected by the CDF II detector, we present a cross section measurement of top-quark pair production with an additional radiated photon, tt??. The events are selected by looking for a lepton (ell), a photon (?), significant transverse momentum imbalance (E<sub>T>), large total transverse energy, and three or more jets, with at least one identified as containing a b quark (b). The tt?? sample requires the photon to have 10 GeV or more of transverse energy, and to be in the central region. Using an event selection optimized for the tt?? candidate sample we measure the production cross section of tt? (?<sub>tt?>), and the ratio of cross sections of the two samples. Control samples in the dilepton+photon and lepton+photon+E<sub>T>, channels are constructed to aid in decay product identification and background measurements. We observe 30 tt?? candidate events compared to the standard model expectation of 26.9 ± 3.4 events. We measure the tt?? cross section (?<sub>tt?>) to be 0.18 ± 0.08 pb, and the ratio of ?<sub>tt?>? to ?<sub>tt?> to be 0.024 ± 0.009. Assuming no tt?? production, we observe a probability of 0.0015 of the background events alone producing 30 events or more, corresponding to 3.0 standard deviations.

  13. Hydrides of CeNi/sub 5/, MmNi/sub 5/, Ca/sub 0/ /sub 2/(Ce/sub 0/ /sub 65/Mm/sub 0/ /sub 35/)/sub 0/ /sub 8/Ni/sub 5/, Ca/sub 0/ /sub 2/Ce/sub 0/ /sub 8/Ni/sub 5/, Ca/sub 0/ /sub 2/Mm/sub 0/ /sub 8/Ni/sub 5/, and mixed CeNi/sub 5//MmNi/sub 5/

    SciTech Connect (OSTI)

    Lakner, J.F.; Chow, T.S.

    1982-09-01

    Six intermetallic alloys (CeNi/sub 5/, MmNi/sub 5/, Ca/sub 0/ /sub 2/(Ce/sub 0/ /sub 65/Mm/sub 0/ /sub 35/)/sub 0/ /sub 8/Ni/sub 5/, Ca/sub 0/ /sub 2/Ce/sub 0/ /sub 8/Ni/sub 5/, Ca/sub 0/ /sub 2/Mm/sub 0/ /sub 8/Ni/sub 5/, and a mixed alloy, CeNi/sub 5//MmNi/sub 5/) were investigated with respect to their suitability to provide high hydrogen capacity and their potential for use in providing substantial hydrogen pressure at both low and high temperatures. A second phase of our investigation dealt with ball-milling and hydriding and dehydriding cycles to produce fine particles for use in hydride powder transfer studies. A summary of several Van't Hoff plots is also included for hydride-forming alloys.

  14. Development of very high J<sub>c> in Ba(Fe<sub>1-xsub>Cox)>2sub>As>2sub> thin films grown on CaF<sub>2sub>

    SciTech Connect (OSTI)

    Tarantini, C.; Kametani, F.; Lee, S.; Jiang, J.; Weiss, J. D.; Jaroszynski, J.; Hellstrom, E. E.; Eom, C. B.; Larbalestier, D. C.

    2014-12-03

    Ba(Fe<sub>1-xsub>Cox)>2sub>As>2sub> is the most tunable of the Fe-based superconductors (FBS) in terms of acceptance of high densities of self-assembled and artificially introduced pinning centres which are effective in significantly increasing the critical current density, J<sub>c>. Moreover, FBS are very sensitive to strain, which induces an important enhancement in critical temperature,T<sub>c>, of the material. In this study we demonstrate that strain induced by the substrate can further improve J<sub>c> of both single and multilayer films by more than that expected simply due to the increase in T<sub>c>. The multilayer deposition of Ba(Fe<sub>1-xsub>Cox)>2sub>As>2sub> on CaF<sub>2sub> increases the pinning force density (F<sub>p=Jc> x ??H) by more than 60% compared to a single layer film, reaching a maximum of 84 GN/m3 at 22.5 T and 4.2 K, the highest value ever reported in any 122 phase.

  15. Li.sub.2 O-Al.sub.2 O.sub.3 -SiO.sub.2 glass ceramic-aluminum containing austenitic stainless steel composite body and a method of producing the same

    DOE Patents [OSTI]

    Cassidy, Roger T. (Monroe, OH)

    1990-05-01

    The present invention relates to a hermetically sealed Li.sub.2 O-Al.sub.2 O.sub.3 -SiO.sub.2 glass ceramic-aluminum containing stainless steel composite body and a method of producing the body. The composite body includes an oxide interfacial region between the glass ceramic and metal, wherein the interfacial region consists essentially of an Al.sub.2 O.sub.3 layer. The interfacial Al.sub.2 O.sub.3 region includes constituents of both the metal and glass ceramic.

  16. Measurement of the Target-Normal Single-Spin Asymmetry A{sub y}{sup n} in the Deep Inelastic Region from the Reaction {sup 3}He{up_arrow}(e,e')

    SciTech Connect (OSTI)

    Katich, Joseph [William and Mary College

    2011-01-01

    A first measurement of the inclusive target single-spin asymmetry, A{sup n}{sub y}, has been performed in deep-inelastic scattering of electrons from a {sup 3}He target polarized normal to the electron scattering plane. This asymmetry is void of contributions at the Born level, and thus is a direct observable for two-photon physics. The experiment was performed in Hall A at Thomas Jefferson National Accelerator Facility from October 2008 through early February 2009. The measurement is the first from a polarized neutron target. The final overall precision is several times better than previously existing SLAC proton data, and significantly extends the kinematic range over which the asymmetry has been measured. The asymmetry was measured at five kinematic points in the deep inelastic scattering region covering Q{sup 2} = 1 - 3 GeV{sup 2} and x{sub B} = 0.16 to 0.41. The asymmetry varied from 0.006 to 0.071 with astatistical precision at the 10{sup -2} level.

  17. Interfacial dislocations in (111) oriented (Ba<sub>0.7sub>Sr>0.3sub>)TiO>3sub> films on SrTiO<sub>3sub> single crystal

    SciTech Connect (OSTI)

    Shen, Xuan; Yamada, Tomoaki; Lin, Ruoqian; Kamo, Takafumi; Funakubo, Hiroshi; Wu, Di; Xin, Huolin L.; Su, Dong

    2015-10-08

    In this study, we have investigated the interfacial structure of epitaxial (Ba,Sr)TiO<sub>3sub> films grown on (111)-oriented SrTiO<sub>3sub> single-crystal substrates using transmission electron microscopy (TEM) techniques. Compared with the (100) epitaxial perovskite films, we observe dominant dislocation half-loop with Burgers vectors of a<110> comprised of a misfit dislocation along <112>, and threading dislocations along <110> or <100>. The misfit dislocation with Burgers vector of a <110> can dissociate into two ½ a <110> partial dislocations and one stacking fault. We found the dislocation reactions occur not only between misfit dislocations, but also between threading dislocations. Via three-dimensional electron tomography, we retrieved the configurations of the threading dislocation reactions. The reactions between threading dislocations lead to a more efficient strain relaxation than do the misfit dislocations alone in the near-interface region of the (111)-oriented (Ba<sub>0.7sub>Sr>0.3sub>)TiO>3sub> films.

  18. Phase equilibria and crystal chemistry of the CaO–1/2 Nd{sub 2}O{sub 3}–CoO{sub z} system at 885 °C in air

    SciTech Connect (OSTI)

    Wong-Ng, W.; Laws, W.; Talley, K.R.; Huang, Q.; Yan, Y.; Martin, J.; Kaduk, J.A.

    2014-07-01

    The phase diagram of the CaO–1/2 Nd{sub 2}O{sub 3}–CoO{sub z} system at 885 °C in air has been determined. The system consists of two calcium cobaltate compounds that have promising thermoelectric properties, namely, the 2D thermoelectric oxide solid solution, (Ca{sub 3?x}Nd{sub x})Co{sub 4}O{sub 9?z} (0?x?0.5), which has a misfit layered structure, and Ca{sub 3}Co{sub 2}O{sub 6} which consists of 1D chains of alternating CoO{sub 6} trigonal prisms and CoO{sub 6} octahedra. Ca{sub 3}Co{sub 2}O{sub 6} was found to be a point compound without the substitution of Nd on the Ca site. The reported Nd{sub 2}CoO{sub 4} phase was not observed at 885 °C. A ternary (Ca{sub 1?x}Nd{sub 1+x})CoO{sub 4?z} (x=0) phase, or (CaNdCo)O{sub 4?z}, was found to be stable at this temperature. A solid solution region of distorted perovskite (Nd{sub 1?x}Ca{sub x})CoO{sub 3?z} (0?x?0.25, space group Pnma) was established. In the peripheral binary systems, while a solid solution region was identified for (Nd{sub 1?x}Ca{sub x}){sub 2}O{sub 3?z} (0?x?0.2), Nd was not found to substitute in the Ca site of CaO. Six solid solution tie-line regions and six three-phase regions were determined in the CaO–Nd{sub 2}O{sub 3}–CoO{sub z} system in air. - Graphical abstract: Phase diagram of the 1/2 Nd{sub 2}O{sub 3}–CaO–CoO{sub x} system at 885 °C, showing the limits of various solid solutions, and the tie-line relationships of various phases. - Highlights: • Phase diagram of the CaO–1/2 Nd{sub 2}O{sub 3}–CoO{sub z} system constructed. • System consists of thermoelectric oxide (Ca{sub 3?x}Nd{sub x})Co{sub 4}O{sub 9?z} (0?x?0.5). • Structures of (Nd{sub 1?x}Ca{sub x})CoO{sub 3?z} and (CaNdCo)O{sub 4?z} determined.

  19. Synthesis of novel MoS{sub 2}/g-C{sub 3}N{sub 4} heterojunction photocatalysts with enhanced hydrogen evolution activity

    SciTech Connect (OSTI)

    Tian, Yuming; Ge, Lei; Wang, Kaiyue; Chai, Yuesheng

    2014-01-15

    Novel MoS{sub 2}/g-C{sub 3}N{sub 4} heterojunction photocatalysts were synthesized via a simple impregnation and heating methods. The products were characterized by X-ray diffraction, transmission electron microscopy and UV–vis diffuse reflectance spectra. The photocatalytic activities of MoS{sub 2}/g-C{sub 3}N{sub 4} samples were evaluated based on the hydrogen evolution experiments under visible light irradiation (? > 400 nm). The UV–vis diffuse reflectance spectra revealed that the MoS{sub 2}/g-C{sub 3}N{sub 4} photocatalysts had strong absorption in the visible light region. The photocatalytic results indicated that the highest H{sub 2} evolution rate of 23.10 ?mol·h{sup ?1} was achieved on the 0.5 wt.% MoS{sub 2}–g-C{sub 3}N{sub 4} sample, which was enhanced by 11.3 times compared to pure g-C{sub 3}N{sub 4}. This study may provide an approach to the development of novel heterojunction photocatalysts for hydrogen production under visible light irradiation. - Highlights: • MoS{sub 2}/g-C{sub 3}N{sub 4} photocatalyst is obtained by simple impregnation and heating methods. • and determined by XRD, TEM, UV-vis diffuse reflectance spectra. • the photocatalysts had strong absorption in the visible light region. • the highest H2 evolution rate was achieved on the 0.5wt% samples.

  20. Interface-dependent magnetotransport properties for thin Pt films on ferrimagnetic Y{sub 3}Fe{sub 5}O{sub 12}

    SciTech Connect (OSTI)

    Shiomi, Y.; Ohtani, T.; Iguchi, S.; Sasaki, T.; Qiu, Z.; Nakayama, H.; Uchida, K.; Saitoh, E.

    2014-06-16

    We have studied magnetoresistance and Hall effects for 1.8-nm-thick Pt films grown on a ferrimagnetic insulator Y{sub 3}Fe{sub 5}O{sub 12} in a wide temperature (0.46–300?K) and magnetic-field (?15 to 15?T) region. In the low-temperature regime where quantum corrections to conductivity are observed, weak antilocalization behavior observed in Pt films is critically suppressed when the film is attached to Y{sub 3}Fe{sub 5}O{sub 12}. Hall resistance in the Pt film is also affected by Y{sub 3}Fe{sub 5}O{sub 12}, and it exhibits logarithmic temperature dependence in a broad temperature range. The magnetotransport properties in the high-field range are significantly influenced by the interface between Pt and Y{sub 3}Fe{sub 5}O{sub 12}.

  1. Surface phase of TiO{sub 2} modified with La{sub 2}O{sub 3} and its effect on the photocatalytic H{sub 2} evolution

    SciTech Connect (OSTI)

    Zhang, Yangyang [College of Chemistry, Chemical Engineering and Environmental Engineering, Liaoning Shihua University, Liaoning, 113001 (China); Zhang, Jing, E-mail: jingzhang_dicp@live.cn [College of Chemistry, Chemical Engineering and Environmental Engineering, Liaoning Shihua University, Liaoning, 113001 (China); Xu, Qian [State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning (China); Yan, Song; Zhao, Shanlin; Luo, Genxiang [College of Chemistry, Chemical Engineering and Environmental Engineering, Liaoning Shihua University, Liaoning, 113001 (China); Li, Can, E-mail: canli@dicp.ac.cn [State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning (China)

    2014-05-01

    Graphical abstract: The La{sub 2}O{sub 3}/TiO{sub 2}-900 °C (or La{sub 2}O{sub 3}/Ti(OH){sub 4}-900 °C), with surface anatase phase, show the similar photocatalytic activity. The presence of the surface anatase phase is important for high photocatalytic activity of TiO{sub 2} modified with La{sub 2}O{sub 3} (La{sub 2}O{sub 3}/Ti(OH){sub 4}-900 °C or La{sub 2}O{sub 3}/Ti(OH){sub 4}-900 °C){sub .} - Highlights: • Loading La{sub 2}O{sub 3} on anatase TiO{sub 2} is an effective method for stabilizing the anatase phases both in the surface and in the bulk region. • The high crystallinity of the surface anatase phase is important for high photocatalytic activity of TiO{sub 2} modified with La{sub 2}O{sub 3.} - Abstract: TiO{sub 2} nanoparticles modified with La{sub 2}O{sub 3} were prepared by an impregnation method using anatase TiO{sub 2} support (La{sub 2}O{sub 3}/TiO{sub 2}) or amorphous Ti(OH){sub 4} support (La{sub 2}O{sub 3}/Ti(OH){sub 4}). The bulk and surface crystalline phases of La{sub 2}O{sub 3}/TiO{sub 2} (or La{sub 2}O{sub 3}/Ti(OH){sub 4}) have been characterized by X-ray powder diffraction (XRD) and UV Raman spectroscopy. Besides, morphology and particle size of La{sub 2}O{sub 3}/TiO{sub 2} and La{sub 2}O{sub 3}/Ti(OH){sub 4} samples have been determined by TEM (transmission electron microscope) and Brunauer–Emmett–Teller (BET), respectively. It is found that the phase transformation and increase of the particle size of TiO{sub 2} can be more effectively inhibited in the La{sub 2}O{sub 3}/TiO{sub 2} than in the La{sub 2}O{sub 3}/Ti(OH){sub 4}. Photocatalytic experiments indicated that the La{sub 2}O{sub 3}/TiO{sub 2} (or La{sub 2}O{sub 3}/Ti(OH){sub 4}) samples with surface anatase phase have the similar overall photocatalytic activities. Moreover, it is found that the high crystallinity of surface anatase phase is benefit for the high photocatalytic activity of TiO{sub 2} modified with La{sub 2}O{sub 3}.

  2. Agency Sub-

    Broader source: Energy.gov (indexed) [DOE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i n c i p a l De p u t y A sCOLONY PROJECTRecord4 TheAgency Sub- agency Title Of

  3. Wireless System Considerations When Implementing NERC Critical...

    Broader source: Energy.gov (indexed) [DOE]

    Standards More Documents & Publications Recommended Practices Guide For Securing ZigBee Wireless Networks in Process Control System Environments Securing WLANs using 802.11i DOE...

  4. North American Electric Reliability Corporation (NERC): Reliability

    Broader source: Energy.gov (indexed) [DOE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergy AEnergy Managing853926 News en INFOGRAPHIC: HowFranklin OrrSamplingof

  5. Learn About NercEnergy - Nercenergy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory ofDid you notHeat PumpsTechnologies | BlandineTechnologiesLearn About

  6. Wireless System Considerations When Implementing NERC Critical

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX E LIST OFAMERICA'S FUTURE.Energy Wind Power Today, 2010,Winners

  7. Synthesis and photoluminescence properties of Ca{sub 19}Mg{sub 2}(PO{sub 4}){sub 14}:Sm{sup 3+} red phosphor for white light emitting diodes

    SciTech Connect (OSTI)

    Zhu, Ge; Ci, Zhipeng; Shi, Yurong; Wang, Yuhua

    2014-07-01

    Highlights: • A novel red phosphor Ca{sub 19}Mg{sub 2}(PO{sub 4}){sub 14}:Sm{sup 3+} was synthesized and investigated firstly. • The structure and characteristic luminescence properties are discussed. • The excellent thermal stability was found and investigated. • It has good color saturation, the CIE is close to that of commercial Y{sub 2}O{sub 3}:Eu{sup 3+}. - Abstract: A series of Sm{sup 3+} doped Ca{sub 19}Mg{sub 2}(PO{sub 4}){sub 14} red phosphors were successfully synthesized. X-ray diffraction analysis indicates that all the samples are single phased. The luminescence property is investigated in detail by measuring their photoluminescence excitation and emission spectra. Ca{sub 19}Mg{sub 2}(PO{sub 4}){sub 14}:Sm{sup 3+} phosphors show strong absorption in 400–410 nm region, which is suitable for application in LEDs. When excited at 403 nm, Ca{sub 19}Mg{sub 2}(PO{sub 4}){sub 14}:Sm{sup 3+} phosphor can emit red emission with CIE chromaticity coordinates (0.615, 0.384). The optimal doping concentration of Sm{sup 3+} doped Ca{sub 19}Mg{sub 2}(PO{sub 4}){sub 14} is measured to be 0.02. The thermal quenching property is also measured and compared with the commercial red phosphor Y{sub 2}O{sub 3}:Eu{sup 3+} (Topstar, TXC-RIA). The results indicate Ca{sub 19}Mg{sub 2}(PO{sub 4}){sub 14}:Sm{sup 3+} phosphors have potential to serve as a red phosphor for white LEDs.

  8. Phase evolution studies in CaZrTi{sub 2}O{sub 7}?RE{sub 2}Ti{sub 2}O{sub 7} (RE?=?Nd{sup 3+}, Sm{sup 3+}) system: Futuristic ceramic host matrices for nuclear waste immobilization

    SciTech Connect (OSTI)

    Jafar, M. Achary, S. N. Tyagi, A. K.

    2014-04-24

    Series of compositions with general stoichiometry as Ca{sub 1?x}Zr{sub 1?x}RE{sub 2x}Ti{sub 2}O{sub 7} (RE?=?Nd{sup 3+}, Sm{sup 3+}) were prepared by solid state reaction and characterized by powder x-ray diffraction technique to unravel the phase fields in the title systems. The phase fields in CaZrTi{sub 2}O{sub 7?}Nd{sub 2}Ti{sub 2}O{sub 7} and CaZrTi{sub 2}O{sub 7?}Sm{sub 2}Ti{sub 2}O{sub 7} systems differed significantly at the rareearth rich regions. The common phase fields like zirconolite-2M, zirconolite-4M, cubic perovskite are observed at the zirconolite rich regions of both systems. Depending on the structure of RE{sub 2}Ti{sub 2}O{sub 7} phase, the cubic pyrochlore or monoclinic RE{sub 2}Ti{sub 2}O{sub 7} phases are observed in the studied system. The observed phase fields in these two systems indicate ionic radius of the rare-earth ion has a dominating role in the phase relations. Further details of the phases and their homogeneity are explained in the text of the manuscript.

  9. Strong electroluminescence from SiO{sub 2}-Tb{sub 2}O{sub 3}-Al{sub 2}O{sub 3} mixed layers fabricated by atomic layer deposition

    SciTech Connect (OSTI)

    Rebohle, L., E-mail: l.rebohle@hzdr.de; Braun, M.; Wutzler, R.; Helm, M.; Skorupa, W. [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden (Germany); Liu, B.; Sun, J. M. [Key Laboratory of Weak Light Nonlinear Photonics, Ministry of Education, School of Physics, Nankai University, Tianjin 300071 (China)

    2014-06-23

    We report on the bright green electroluminescence (EL) with power efficiencies up to 0.15% of SiO{sub 2}-Tb{sub 2}O{sub 3}-mixed layers fabricated by atomic layer deposition and partly co-doped with Al{sub 2}O{sub 3}. The electrical, EL, and breakdown behavior is investigated as a function of the Tb and the Al concentration. Special attention has been paid to the beneficial role of Al{sub 2}O{sub 3} co-doping which improves important device parameters. In detail, it increases the maximum EL power efficiency and EL decay time, it nearly doubles the fraction of excitable Tb{sup 3+} ions, it shifts the region of high EL power efficiencies to higher injection currents, and it reduces the EL quenching over the device lifetime by an approximate factor of two. It is assumed that the presence of Al{sub 2}O{sub 3} interferes the formation of Tb clusters and related defects. Therefore, the system SiO{sub 2}-Tb{sub 2}O{sub 3}-Al{sub 2}O{sub 3} represents a promising alternative for integrated, Si-based light emitters.

  10. Measurement of the correlation between flow harmonics of different order in lead-lead collisions at ?s<sub>NN> = 2.76 TeV with the ATLAS detector

    SciTech Connect (OSTI)

    Aad, G.

    2015-09-14

    Correlations between the elliptic or triangular flow coefficients v<sub>m> (m=2 or 3) and other flow harmonics v<sub>n> (n=2 to 5) are measured using ?s<sub>NN>=2.76 TeV Pb+Pb collision data collected in 2010 by the ATLAS experiment at the LHC, corresponding to an integrated luminosity of 7 ?b-1. The v<sub>m-vn> correlations are measured in midrapidity as a function of centrality, and, for events within the same centrality interval, as a function of event ellipticity or triangularity defined in a forward rapidity region. For events within the same centrality interval, v<sub>3sub> is found to be anticorrelated with v<sub>2sub> and this anticorrelation is consistent with similar anticorrelations between the corresponding eccentricities, ?<sub>2sub> and ?<sub>3sub>. However, it is observed that v<sub>4sub> increases strongly with v<sub>2sub>, and v<sub>5sub> increases strongly with both v<sub>2sub> and v<sub>3sub>. The trend and strength of the vm-vn correlations for n=4 and 5 are found to disagree with ?<sub>m-?n> correlations predicted by initial-geometry models. Instead, these correlations are found to be consistent with the combined effects of a linear contribution to vn and a nonlinear term that is a function of v2<sub>2sub> or of v<sub>2sub>v>3sub>, as predicted by hydrodynamic models. A simple two-component fit is used to separate these two contributions. The extracted linear and nonlinear contributions to v<sub>4sub> and v<sub>5sub> are found to be consistent with previously measured event-plane correlations.

  11. Structural study of Ca{sub 2}Gd{sub 2}Ge{sub 2}O{sub 9} and optical spectroscopy of the Eu{sup 3+} dopant ion

    SciTech Connect (OSTI)

    Piccinelli, Fabio, E-mail: fabio.piccinelli@univr.it; Pedroni, Marco; Cagliero, Stefano; Speghini, Adolfo; Bettinelli, Marco

    2014-04-01

    The new rare earth-based germanate compound Ca{sub 2}Gd{sub 2}Ge{sub 2}O{sub 9} (orthorhombic (Pnma) crystal structure), has been characterized and investigated for the first time, using synchrotron powder X-ray diffraction. From Rietveld refinement calculations on the collected powder pattern we observe an inhomogeneous distribution of the two available cationic sites by Gd{sup 3+} and Ca{sup 2+} ions. In particular, the former prefers the occupation (67.5%) of the site with 8-fold coordination. In addition, we observed a not negligible degree of distortion of the Ge{sub 2}O{sub 7}{sup 6?} unit. Finally, luminescence spectra and decay curves of Eu{sup 3+} doped Ca{sub 2}Gd{sub 2}Ge{sub 2}O{sub 9} were measured and analysed taking into account the structural features of the host. The results reveal that this material shows strong red luminescence upon excitation in the region where blue LEDs emit (470 nm). - Graphical abstract: The structural study on Ca{sub 2}Gd{sub 2}Ge{sub 2}O{sub 9} exploiting synchrotron X-ray diffraction, allows us to determine the detailed geometry of the metal coordination polyhedra, which is closely related to the emission luminescence spectroscopy of the Eu{sup 3+} dopant ion introduced as impurity in this host. - Highlights: • The crystal structure of the Ca{sub 2}Gd{sub 2}Ge{sub 2}O{sub 9} was determined. • Gd{sup 3+} ion is distributed on two crystal sites with different occupation. • A structural study focused on the metal coordination polyhedra was performed. • Two emitting sites are detected for Eu{sup 3+} dopant ion in Ca{sub 2}Gd{sub 2}Ge{sub 2}O{sub 9}. • Strong red luminescence by excitation in the region where blue LEDs emit was found.

  12. K{sub 2}Fe{sub 2}B{sub 2}O{sub 7}: A transparent nonlinear optical crystal with frustrated magnetism

    SciTech Connect (OSTI)

    Wang Yonggang [Beijing Center for Crystal Research and Development, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Li, R.K., E-mail: rkli@mail.ipc.ac.c [Beijing Center for Crystal Research and Development, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China)

    2010-06-15

    A new noncentrosymmetric ferroborate crystal, K{sub 2}Fe{sub 2}B{sub 2}O{sub 7}, has been grown from high temperature melt. Structure solution from single crystal X-ray diffraction shows that the title compound crystallizes in a trigonal space group P321 with cell dimensions of a=8.7475(12) A and c=8.5124(17) A. In the structure, FeO{sub 4} tetrahedron shares its three basal oxygen atoms with BO{sub 3} triangles forming a two-dimensional layer in the ab plane and the layers are connected by the apical Fe-O bonds along the c direction. The crystal is transparent in the visible and near infrared region from 500 to 2000 nm with three pronounced absorption bands ascribed to d-d transitions of tetrahedrally coordinated Fe{sup 3+} ions. Though, structurally analog to K{sub 2}Al{sub 2}B{sub 2}O{sub 7}, the further twisting of the BO{sub 3} groups between adjacent layers reduces its optical nonlinearity to a second-harmonic generation intensity of about 0.4 times that of KDP. Spin-glass behavior is observed at 20 K which is probably due to geometrically magnetic frustration of the triangular Fe net in the ab plane. - Graphical abstract: Single crystal of a new ferroborate K{sub 2}Fe{sub 2}B{sub 2}O{sub 7}, space group P321, a=8.7475(3) A, c=8.5124(3) A, was obtained and characterized. It exhibits considerable SHG efficiency and frustrated magnetism originated from the triangular Fe net in the ab plane.

  13. A novel Bi-based phosphomolybdate photocatalyst K{sub 2}Bi(PO{sub 4})(MoO{sub 4}): Crystal structure, electronic structure and photocatalytic activity

    SciTech Connect (OSTI)

    Huang, Hongwei, E-mail: hhw@cugb.edu.cn [National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Chen, Gong; Wang, Shuobo [National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Kang, Lei; Lin, Zheshuai [Center for Crystal Research and Development, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Zhang, Yihe [National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China)

    2014-03-01

    Graphical abstract: - Highlights: • A new type of phosphomolybdate K{sub 2}Bi(PO{sub 4})(MoO{sub 4}) photocatalyst was successfully synthesized. • The products synthesized at 600 °C were mainly composed of nano-cubes. • The indirect band gap of K{sub 2}Bi(PO{sub 4})(MoO{sub 4}) has been determined to be 2.93 eV. • K{sub 2}Bi(PO{sub 4})(MoO{sub 4}) synthesized at 600 °C exhibits the highest photocatalytic activity. • The electronic structure was calculated by density functional calculations. - Abstract: A novel phosphomolybdate photocatalyst K{sub 2}Bi(PO{sub 4})(MoO{sub 4}) has been successfully developed via a solid-state reaction. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), diffuse reflectance spectrum (DRS) and photoluminescence (PL) spectra. The photocatalytic activities of the samples prepared at different temperature were determined by the photooxidative decomposition of methylene blue (MB) in aqueous solution. The results revealed that K{sub 2}Bi(PO{sub 4})(MoO{sub 4}) can be used as an effective photocatalyst under UV–vis irradiation and the nanocubes obtained at 600 °C exhibits the highest photocatalytic activity. The photodegradation of MB by K{sub 2}Bi(PO{sub 4})(MoO{sub 4}) nanocrystals followed the first-order kinetics. Theoretical calculations on electronic structure confirmed the indirect optical transitions property in the absorption edge region of K{sub 2}Bi(PO{sub 4})(MoO{sub 4}), and the orbital constitutions of CB and VB were also analyzed.

  14. Synthesis and properties of new CdSe-AgI-As{sub 2}Se{sub 3} chalcogenide glasses

    SciTech Connect (OSTI)

    Kassem, M.; ULCO, LPCA, EAC CNRS 4493 F-59140 Dunkerque ; Le Coq, D.; Fourmentin, M.; Hindle, F.; Bokova, M.; Cuisset, A.; Masselin, P.; Bychkov, E.; ULCO, LPCA, EAC CNRS 4493 F-59140 Dunkerque

    2011-02-15

    Research highlights: {yields} Determination of the glass-forming region in the pseudo-ternary CdSe-AgI-As{sub 2}Se{sub 3} system. {yields} Characterization of macroscopic properties of the new CdSe-AgI-As{sub 2}Se{sub 3} glasses. {yields} Far infrared transmission of chalcogenide glasses. {yields} Characterization of the total conductivity of CdSe-AgI-As{sub 2}Se{sub 3} glasses. -- Abstract: The glass-forming region in the pseudo-ternary CdSe-AgI-As{sub 2}Se{sub 3} system was determined. Measurements including differential scanning calorimetry (DSC), density, and X-ray diffraction were performed. The effect resulting from the addition of CdSe or AgI has been highlighted by examining three series of different base glasses. The characteristic temperatures of the glass samples, including glass transition (T{sub g}), crystallisation (T{sub x}), and melting (T{sub m}) temperatures are reported and used to calculate their {Delta}T = T{sub x} - T{sub g} and their Hruby, H{sub r} = (T{sub x} - T{sub g})/(T{sub m} - T{sub x}), criteria. Evolution of the total electrical conductivity {sigma} and the room temperature conductivity {sigma}{sub 298} was also studied. The terahertz transparency domain in the 50-600 cm{sup -1} region was pointed for different chalcogenide glasses (ChGs) and the potential of the THz spectroscopy was suggested to obtain structural information on ChGs.

  15. Wave-function engineering and absorption spectra in Si{sub 0.16}Ge{sub 0.84}/Ge{sub 0.94}Sn{sub 0.06}/Si{sub 0.16}Ge{sub 0.84} strained on relaxed Si{sub 0.10}Ge{sub 0.90} type I quantum well

    SciTech Connect (OSTI)

    Yahyaoui, N., E-mail: naima.yahyaoui@yahoo.fr, E-mail: moncef-said@yahoo.fr; Sfina, N.; Said, M., E-mail: naima.yahyaoui@yahoo.fr, E-mail: moncef-said@yahoo.fr [Laboratoire de la Matière Condensée et des Nanosciences (LMCN), Département de Physique, Faculté des Sciences de Monastir, Avenue de l'Environnement, 5019 Monastir (Tunisia); Lazzari, J.-L. [Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), UMR CNRS 7325, Aix-Marseille Université, Case 913, Campus de Luminy, 13288 Marseille cedex 9 (France); Bournel, A. [Institut d'Electronique Fondamentale (IEF), UMR CNRS 8622, Université Paris-Sud, Bât. 220, 91405 Orsay cedex (France)

    2014-01-21

    We theoretically investigate germanium-tin alloy as a semiconductor for the design of near infrared optical modulators in which the Ge{sub 1?x}Sn{sub x} alloy is the active region. We have calculated the electronic band parameters for heterointerfaces between strained Ge{sub 1?x}Sn{sub x} and relaxed Si{sub 1?y}Ge{sub y}. Then, a type-I strain-compensated Si{sub 0.10}Ge{sub 0.90}/Si{sub 0.16}Ge{sub 0.84}/Ge{sub 0.94}Sn{sub 0.06} quantum well heterostructure optimized in terms of compositions and thicknesses is studied by solving Schrödinger equation without and under applied bias voltage. The strong absorption coefficient (>1.5?×?10{sup 4}?cm{sup ?1}) and the shift of the direct transition under large Stark effect at 3?V are useful characteristics for the design of optoelectronic devices based on compressively strained IV-IV heterostructures at near infrared wavelengths.

  16. Cationic disorder and Mn{sup 3+}/Mn{sup 4+} charge ordering in the B? and B? sites of Ca{sub 3}Mn{sub 2}NbO{sub 9} perovskite: a comparison with Ca{sub 3}Mn{sub 2}WO{sub 9}

    SciTech Connect (OSTI)

    López, C.A.; Saleta, M.E.; Pedregosa, J.C.; Sánchez, R.D.; Alonso, J.A.; and others

    2014-02-15

    We describe the preparation, crystal structure determination, magnetic and transport properties of two novel Mn-containing perovskites, with a different electronic configuration for Mn atoms located in B site. Ca{sub 3}Mn{sup 3+}{sub 2}WO{sub 9} and Ca{sub 3}Mn{sup 3+/4+}{sub 2}NbO{sub 9} were synthesized by standard ceramic procedures; the crystallographic structure was studied from X-ray powder diffraction (XRPD) and neutron powder diffraction (NPD). Both phases exhibit a monoclinic symmetry (S.G.: P2{sub 1}/n); Ca{sub 3}Mn{sub 2}WO{sub 9} presents a long-range ordering over the B sites, whereas Ca{sub 3}Mn{sub 2}NbO{sub 9} is strongly disordered. By “in-situ” NPD, the temperature evolution of the structure study presents an interesting evolution in the octahedral size (?Mn–O?) for Ca{sub 3}Mn{sub 2}NbO{sub 9}, driven by a charge ordering effect between Mn{sup 3+} and Mn{sup 4+} atoms, related to the anomaly observed in the transport measurements at T?160 K. Both materials present a magnetic order below T{sub C}=30 K and 40 K for W and Nb materials, respectively. The magneto-transport measurements display non-negligible magnetoresistance properties in the paramagnetic regime. - Graphical abstract: Comparison between the octahedron size and the magnetic behaviour for Ca{sub 3}Mn{sub 2}NbO{sub 9} in the temperature region where the charge and magnetic order occur. Display Omitted - Highlights: • Two novel Mn-containing double perovskites were obtained by solid-state reactions. • Both double perovskites are monoclinic (P2{sub 1}/n) determined by XRPD and NPD. • Ca{sub 3}Mn{sub 2}WO{sub 9} contains Mn{sup 3+} while Ca{sub 3}Mn{sub 2}NbO{sub 9} includes mixed-valence cations Mn{sup 3+}/Mn{sup 4+}. • Ca{sub 3}Mn{sub 2}NbO{sub 9} presents a charge-ordering effect between Mn{sup 3+} and Mn{sup 4+} evidenced by NPD. • The magnetic and transport studies evidenced the charge ordering in Ca{sub 3}Mn{sub 2}NbO{sub 9}.

  17. Relevant Studies for NERCs Analysis of EPAs Clean Power Plan...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    shown in the following table, including various mixes of offshore wind, onshore wind, solar photovoltaic, and dispersed wind. The impacts on coal- and gas-fired generators were...

  18. Structural, spectroscopic and dielectric investigations on Ba{sub 8}Zn(Nb{sub 6-x}Sb{sub x})O{sub 24} microwave ceramics

    SciTech Connect (OSTI)

    Suresh, M.K.; John, Annamma; Thomas, J.K.; Wariar, P.R.S. [Department of Physics, Mar Ivanios College, Thiruvananthapuram 695015, Kerala (India)] [Department of Physics, Mar Ivanios College, Thiruvananthapuram 695015, Kerala (India); Solomon, Sam, E-mail: samdmrl@yahoo.com [Department of Physics, Mar Ivanios College, Thiruvananthapuram 695015, Kerala (India)] [Department of Physics, Mar Ivanios College, Thiruvananthapuram 695015, Kerala (India)

    2010-10-15

    Ba{sub 8}Zn(Nb{sub 6-x}Sb{sub x})O{sub 24} (x = 0, 0.3, 0.6, 0.9, 1.2, 1.5, 1.8 and 2.4) ceramics were prepared through the conventional solid-state route. The materials were calcined at 1250 {sup o}C and sintered in the range 1400-1425 {sup o}C. The structure of the system was analyzed by X-ray diffraction, Fourier transform infrared and Raman spectroscopic methods. The theoretical and experimental densities were calculated. The microstructure of the sintered pellets was analyzed using scanning electron microscopy. The low frequency dielectric properties were studied in the frequency range 50 Hz-2 MHz. The dielectric constant ({epsilon}{sub r}), temperature coefficient of resonant frequency ({tau}{sub f}) and the unloaded quality factor (Q{sub u}) are measured in the microwave frequency region using cavity resonator method. The {tau}{sub f} values of the samples reduced considerably with the increase in Sb concentration. The materials have intense emission lines in the visible region. The compositions have good microwave dielectric properties and photoluminescence and hence are suitable for dielectric resonator and ceramic laser applications.

  19. Structural, electronic and magnetic properties of the series of double perovskites (Ca,Sr){sub 2?x}La{sub x}FeIrO{sub 6}

    SciTech Connect (OSTI)

    Bufaiçal, L.; Adriano, C.; Lora-Serrano, R.; Duque, J.G.S.; Mendonça-Ferreira, L.; Rojas-Ayala, C.; Baggio-Saitovitch, E.; Bittar, E.M.; Pagliuso, P.G.

    2014-04-01

    Polycrystalline samples of the series of double perovskites Sr{sub 2?x}La{sub x}FeIrO{sub 6} were synthesized. Their structural, electronic and magnetic properties were investigated by X-ray powder diffraction, Mössbauer spectroscopy, magnetic susceptibility, heat capacity and electrical resistivity experiments. The compounds crystallize in a monoclinic structure and were fitted in space group P2{sub 1}/n, with a significant degree of Fe/Ir cationic disorder. As in Ca{sub 2?x}La{sub x}FeIrO{sub 6} the Sr-based system seems to evolve from an antiferromagnetic ground state for the end members (x=0.0 and x=2.0) to a ferrimagnetic order in the intermediate regions (x?1). Since Mössbauer spectra indicate that Fe valence remains 3+ with doping, this tendency of change in the nature of the microscopic interaction could be attributed to Ir valence changes, induced by La{sup 3+} electrical doping. Upon comparing both Ca and Sr series, Sr{sub 2?x}La{sub x}FeIrO{sub 6} is more structurally homogenous and presents higher magnetization and transition temperatures. Magnetic susceptibility measurements at high temperatures on Sr{sub 1.2}La{sub 0.8}FeIrO{sub 6} indicate a very high ferrimagnetic Curie temperature T{sub C}?700K. For the Sr{sub 2}FeIrO{sub 6} compound, electrical resistivity experiments under applied pressure suggest that this material might be a Mott insulator. - Graphical abstract: The Weiss constant as a function of La doping for the (Ca,Sr){sub 2?x}La{sub x}FeIrO{sub 6} series, indicating changes in Fe–Ir magnetic coupling on both families. - Highlights: • The double perovskite series (Ca,Sr){sub 2?x}La{sub x}FeIrO{sub 6} were synthesized. • Changes in the Fe-Ir magnetic coupling due to La doping on both series. • Evidence of high T{sub C} on Sr{sub 1.2}La{sub 0.8}FeIrO{sub 6}. • Indication of Mott insulator behavior on Sr{sub 2}FeIrO{sub 6}.

  20. New chalcogenide glasses in the CdTe-AgI-As{sub 2}Te{sub 3} system

    SciTech Connect (OSTI)

    Kassem, M.; Le Coq, D.; Boidin, R.; Bychkov, E.; ULCO, LPCA, EA 4493, F-59140 Dunkerque

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer Determination of the glass-forming region in the pseudo-ternary CdTe-AgI-As{sub 2}Te{sub 3} system. Black-Right-Pointing-Pointer Characterization of macroscopic properties of the new CdTe-AgI-As{sub 2}Te{sub 3} glasses. Black-Right-Pointing-Pointer Characterization of the total conductivity of CdTe-AgI-As{sub 2}Te{sub 3} glasses. Black-Right-Pointing-Pointer Comparison between the selenide and telluride equivalent systems. -- Abstract: Chalcogenide glasses in the pseudo-ternary CdTe-AgI-As{sub 2}Te{sub 3} system were synthesized and the glass-forming range was determined. The maximum content of CdTe in this glass system was found to be equal to 15 mol.%. The macroscopic characterizations of samples have consisted in Differential Scanning Calorimetry, density, and X-ray diffraction measurements. The cadmium telluride addition does not generate any significant change in the glass transition temperature but the resistance of binary AgI-As{sub 2}Te{sub 3} glasses towards crystallisation is estimated to be decreasing on the base of {Delta}T = T{sub x} - T{sub g} parameter. The total electrical conductivity {sigma} was measured by complex impedance spectroscopy. First, the CdTe additions in the (AgI){sub 0.5}(As{sub 2}Te{sub 3}){sub 0.5} host glass, (CdTe){sub x}(AgI){sub 0.5-x/2}(As{sub 2}Te{sub 3}){sub 0.5-x/2} lead to a conductivity decrease at x {<=} 0.05. Then, the behaviour is reversed at 0.05 {<=} x {<=} 0.15. The obtained results are discussed by comparison with the equivalent selenide system.

  1. Glass formation and the third harmonic generation of Cu{sub 2}Se–GeSe{sub 2}–As{sub 2}Se{sub 3} glasses

    SciTech Connect (OSTI)

    Reshak, A. H.; Klymovych, O. S.; Zmiy, O. F.; Myronchuk, G. L.; Zamuruyeva, O. V.; Alahmed, Z. A.; Chyský, J.; Bila, Jiri; Kamarudin, H.

    2014-10-14

    We have performed the investigation of the nonlinear optical properties namely the third harmonic generation (THG) of the glass-formation region in the Cu{sub 2}Se–GeSe{sub 2}–As{sub 2}Se{sub 3} system. The samples were synthesized by direct single-temperature method from high-purity elementary substances. We have found that the value of disorder parameter ? depends on the composition of the glassy alloys. The measurements show that increasing the Cu{sub 2}Se concentration leads to increased slope of the absorption edge, which may be explained by the decrease of the height of random potential relief for the electrons in the tails of the state density which border the band edges. A very sharp increase in the THG at low temperature was observed. Significant enhancement in THG was obtained with decreasing the energy gap, which agreed well with the nonlinear optical susceptibilities obtained from other glasses.

  2. Area 2. Use Of Engineered Nanoparticle-Stabilized CO<sub>2sub> Foams To Improve Volumetric Sweep Of CO<sub>2sub> EOR Processes

    SciTech Connect (OSTI)

    DiCarlo, David; Huh, Chun; Johnston, Keith P.

    2015-01-31

    The goal of this project was to develop a new CO<sub>2 sub>injection enhanced oil recovery (CO<sub>2sub>-EOR) process using engineered nanoparticles with optimized surface coatings that has better volumetric sweep efficiency and a wider application range than conventional CO<sub>2sub>-EOR processes. The main objectives of this project were to (1) identify the characteristics of the optimal nanoparticles that generate extremely stable CO<sub>2sub> foams in situ in reservoir regions without oil; (2) develop a novel method of mobility control using “self-guiding” foams with smart nanoparticles; and (3) extend the applicability of the new method to reservoirs having a wide range of salinity, temperatures, and heterogeneity. Concurrent with our experimental effort to understand the foam generation and transport processes and foam-induced mobility reduction, we also developed mathematical models to explain the underlying processes and mechanisms that govern the fate of nanoparticle-stabilized CO<sub>2sub> foams in porous media and applied these models to (1) simulate the results of foam generation and transport experiments conducted in beadpack and sandstone core systems, (2) analyze CO<sub>2sub> injection data received from a field operator, and (3) aid with the design of a foam injection pilot test. Our simulator is applicable to near-injection well field-scale foam injection problems and accounts for the effects due to layered heterogeneity in permeability field, foam stabilizing agents effects, oil presence, and shear-thinning on the generation and transport of nanoparticle-stabilized C/W foams. This report presents the details of our experimental and numerical modeling work and outlines the highlights of our findings.

  3. Study of B??X<sub>u>l?? decays in BB? events tagged by a fully reconstructed B-meson decay and determination of |V<sub>ub>|

    SciTech Connect (OSTI)

    Lees, J. P.; Poireau, V.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Milanes, D. A.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Brown, D. N.; Kerth, L. T.; Kolomensky, Yu. G.; Lynch, G.; Tackmann, K.; Koch, H.; Schroeder, T.; Asgeirsson, D. J.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; Khan, A.; Blinov, V. E.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Yushkov, A. N.; Bondioli, M.; Kirkby, D.; Lankford, A. J.; Mandelkern, M.; Stoker, D. P.; Atmacan, H.; Gary, J. W.; Liu, F.; Long, O.; Vitug, G. M.; Campagnari, C.; Hong, T. M.; Kovalskyi, D.; Richman, J. D.; West, C. A.; Eisner, A. M.; Kroseberg, J.; Lockman, W. S.; Martinez, A. J.; Schalk, T.; Schumm, B. A.; Seiden, A.; Cheng, C. H.; Doll, D. A.; Echenard, B.; Flood, K. T.; Hitlin, D. G.; Ongmongkolkul, P.; Porter, F. C.; Rakitin, A. Y.; Andreassen, R.; Dubrovin, M. S.; Huard, Z.; Meadows, B. T.; Sokoloff, M. D.; Sun, L.; Bloom, P. C.; Ford, W. T.; Gaz, A.; Nagel, M.; Nauenberg, U.; Smith, J. G.; Wagner, S. R.; Ayad, R.; Toki, W. H.; Spaan, B.; Kobel, M. J.; Schubert, K. R.; Schwierz, R.; Bernard, D.; Verderi, M.; Clark, P. J.; Playfer, S.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cibinetto, G.; Fioravanti, E.; Garzia, I.; Luppi, E.; Munerato, M.; Negrini, M.; Petrella, A.; Piemontese, L.; Santoro, V.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Nicolaci, M.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; Zallo, A.; Contri, R.; Guido, E.; Lo Vetere, M.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Bhuyan, B.; Prasad, V.; Lee, C. L.; Morii, M.; Edwards, A. J.; Adametz, A.; Marks, J.; Uwer, U.; Bernlochner, F. U.; Ebert, M.; Lacker, H. M.; Lueck, T.; Dauncey, P. D.; Tibbetts, M.; Behera, P. K.; Mallik, U.; Chen, C.; Cochran, J.; Meyer, W. T.; Prell, S.; Rosenberg, E. I.; Rubin, A. E.; Gritsan, A. V.; Guo, Z. J.; Arnaud, N.; Davier, M.; Grosdidier, G.; Le Diberder, F.; Lutz, A. M.; Malaescu, B.; Roudeau, P.; Schune, M. H.; Stocchi, A.; Wormser, G.; Lange, D. J.; Wright, D. M.; Bingham, I.; Chavez, C. A.; Coleman, J. P.; Fry, J. R.; Gabathuler, E.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; Di Lodovico, F.; Sacco, R.; Sigamani, M.; Cowan, G.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Hafner, A.; Prencipe, E.; Alwyn, K. E.; Bailey, D.; Barlow, R. J.; Jackson, G.; Lafferty, G. D.; Cenci, R.; Hamilton, B.; Jawahery, A.; Roberts, D. A.; Simi, G.; Dallapiccola, C.; Cowan, R.; Dujmic, D.; Sciolla, G.; Lindemann, D.; Patel, P. M.; Robertson, S. H.; Schram, M.; Biassoni, P.; Lazzaro, A.; Lombardo, V.; Neri, N.; Palombo, F.; Stracka, S.; Cremaldi, L.; Godang, R.; Kroeger, R.; Sonnek, P.; Summers, D. J.; Nguyen, X.; Taras, P.; De Nardo, G.; Monorchio, D.; Onorato, G.; Sciacca, C.; Raven, G.; Snoek, H. L.; Jessop, C. P.; Knoepfel, K. J.; LoSecco, J. M.; Wang, W. F.; Honscheid, K.; Kass, R.; Brau, J.; Frey, R.; Sinev, N. B.; Strom, D.; Torrence, E.; Feltresi, E.; Gagliardi, N.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Ben-Haim, E.; Bomben, M.; Bonneaud, G. R.; Briand, H.; Calderini, G.; Chauveau, J.; Hamon, O.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Sitt, S.; Biasini, M.; Manoni, E.; Pacetti, S.; Rossi, A.; Angelini, C.; Batignani, G.; Bettarini, S.; Carpinelli, M.; Casarosa, G.; Cervelli, A.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Oberhof, B.; Paoloni, E.; Perez, A.; Rizzo, G.; Walsh, J. J.; Lopes Pegna, D.; Lu, C.; Olsen, J.; Smith, A. J. S.; Telnov, A. V.; Anulli, F.; Cavoto, G.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Li Gioi, L.; Mazzoni, M. A.; Piredda, G.; Bünger, C.; Grünberg, O.; Hartmann, T.; Leddig, T.; Schröder, H.; Waldi, R.; Adye, T.; Olaiya, E. O.; Wilson, F. F.; Emery, S.; Hamel de Monchenault, G.; Vasseur, G.; Yèche, Ch.; Aston, D.; Bard, D. J.; Bartoldus, R.; Cartaro, C.; Convery, M. R.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Field, R. C.; Franco Sevilla, M.; Fulsom, B. G.; Gabareen, A. M.; Graham, M. T.; Grenier, P.; Hast, C.; Innes, W. R.; Kelsey, M. H.; Kim, H.; Kim, P.; Kocian, M. L.; Leith, D. W. G. S.; Lewis, P.; Li, S.; Lindquist, B.; Luitz, S.; Luth, V.; Lynch, H. L.; MacFarlane, D. B.; Muller, D. R.; Neal, H.; Nelson, S.; Ofte, I.; Perl, M.; Pulliam, T.; Ratcliff, B. N.; Roodman, A.; Salnikov, A. A.; Schindler, R. H.; Snyder, A.; Su, D.; Sullivan, M. K.; Va’vra, J.; Wagner, A. P.; Weaver, M.; Wisniewski, W. J.; Wittgen, M.; Wright, D. H.; Wulsin, H. W.; Yarritu, A. K.; Young, C. C.; Ziegler, V.; Park, W.; Purohit, M. V.; White, R. M.; Wilson, J. R.; Randle-Conde, A.; Sekula, S. J.; Bellis, M.; Benitez, J. F.; Burchat, P. R.

    2012-08-07

    We report measurements of partial branching fractions for inclusive charmless semileptonic B decays B¯¯¯?X<sub>u>l?¯ and the determination of the Cabibbo–Kobayashi–Maskawa (CKM) matrix element |V<sub>ub>|. The analysis is based on a sample of 467×10? ?(4S)?BB¯¯¯ decays recorded with the BABAR detector at the PEP-II e?e? storage rings. We select events in which the decay of one of the B mesons is fully reconstructed and an electron or a muon signals the semileptonic decay of the other B meson. We measure partial branching fractions ?B in several restricted regions of phase space and determine the CKM element |V<sub>ub>| based on different QCD predictions. For decays with a charged lepton momentum p*<sub>l>>1.0 GeV in the B meson rest frame, we obtain ?B=(1.80±0.13stat±0.15sys±0.02theo)×10?³ from a fit to the two-dimensional M<sub>X>-q² distribution. Here, M<sub>X> refers to the invariant mass of the final state hadron X and q² is the invariant mass squared of the charged lepton and neutrino. From this measurement we extract |V<sub>ub>|=(4.33±0.24<sub>exp>?±0.15<sub>theo>)×10?³ as the arithmetic average of four results obtained from four different QCD predictions of the partial rate. We separately determine partial branching fractions for B¯¯¯0 and B? decays and derive a limit on the isospin breaking in B¯¯¯?X<sub>u>l?¯ decays.

  4. New insulating antiferromagnetic quaternary iridates MLa<sub>10sub>Ir>4sub>O>24sub> (M=Sr, Ba)

    SciTech Connect (OSTI)

    Zhao, Qingbiao; Han, Fei; Stoumpos, Constantinos C.; Han, Tian -Heng; Li, Hao; Mitchell, J. F.

    2015-07-01

    Recently, oxides of Ir4+ have received renewed attention in the condensed matter physics community, as it has been reported that certain iridates have a strongly spin-orbital coupled (SOC) electronic state, J<sub>eff> = ½, that defines the electronic and magnetic properties. The canonical example is the Ruddlesden-Popper compound Sr<sub>2sub>IrO>4sub>, which has been suggested as a potential route to a new class of high temperature superconductor due to the formal analogy between J<sub>eff> = ½ and the S = ½ state of the cuprate superconductors. The quest for other iridium oxides that present tests of the underlying SOC physics is underway. In this spirit, here we report the synthesis and physical properties of two new quaternary tetravalent iridates, MLa<sub>10sub>Ir>4sub>O>24sub> (M = Sr, Ba). The crystal structure of both compounds features isolated IrO<sub>6sub> octahedra in which the electronic configuration of Ir is d5. As a result, both compounds order antiferromagnetically despite the lack of obvious superexchange pathways, and resistivity measurement shows that SrLa<sub>10sub>Ir>4sub>O>24sub> is an insulator.

  5. Polytypism, polymorphism, and superconductivity in TaSe<sub>2sub>–xTex>

    SciTech Connect (OSTI)

    Luo, Huixia; Xie, Weiwei; Tao, Jing; Inoue, Hiroyuki; Gyenis, András; Krizan, Jason W.; Yazdani, Ali; Zhu, Yimei; Cava, Robert Joseph

    2015-03-03

    Polymorphism in materials often leads to significantly different physical properties - the rutile and anatase polymorphs of TiO? are a prime example. Polytypism is a special type of polymorphism, occurring in layered materials when the geometry of a repeating structural layer is maintained but the layer stacking sequence of the overall crystal structure can be varied; SiC is an example of a material with many polytypes. Although polymorphs can have radically different physical properties, it is much rarer for polytypism to impact physical properties in a dramatic fashion. Here we study the effects of polytypism and polymorphism on the superconductivity of TaSe?, one of the archetypal members of the large family of layered dichalcogenides. We show that it is possible to access 2 stable polytypes and 2 stable polymorphs in the TaSe<sub>2-xsub>Tex> solid solution, and find that the 3R polytype shows a superconducting transition temperature that is between 6 and 17 times higher than that of the much more commonly found 2H polytype. Thus, the reason for this dramatic change is not apparent, but we propose that it arises either from a remarkable dependence of T<sub>c> on subtle differences in the characteristics of the single layers present, or from a surprising effect of the layer stacking sequence on electronic properties that instead are expected to be dominated by the properties of a single layer in materials of this kind.

  6. Synthesis, structural, magnetic and electrical properties of Co{sub 1?x}Zn{sub x}Fe{sub 2}O{sub 4} (x = 0.0, 0.2) nanoparticles

    SciTech Connect (OSTI)

    Deligöz, H.; Baykal, A.; Toprak, M.S.; Yildirim Beyazit University, Dept of Materials Science and Engineering, Ulus, Ankara ; Tanr?verdi, E.E.; Durmus, Z.; Sözeri, H.

    2013-02-15

    Graphical abstract: The variations of imaginary part of dielectric permittivity (??) of TEG@Co{sub 1?x}Zn{sub x}Fe{sub 2}O{sub 4} nanocomposite as a function of temperature and frequency for (A) x = 0.0 and (B) x = 0.2. Display Omitted Highlights: ? Nearly monodisperse Zn{sub x}Co{sub 1?x}Fe{sub 2}O{sub 4} nanocomposite were prepared via hydrothermal method. ? The ac conductivity showed a temperature dependent behavior at low frequencies. ? dc conductivity of Co{sub 0.8}Zn{sub 0.2}Fe{sub 2}O{sub 4} nanoparticle are found to obey the Arrhenius plot. ? Also these materials may be used in electronic devices and microwave devices. -- Abstract: Co{sub 1?x}Zn{sub x}Fe{sub 2}O{sub 4} spinel nanoparticles with Zn concentrations of x = 0.0, 0.2 were prepared by a hydrothermal route in the presence of triethylene glycol (TEG). The structural, magnetic, electrical and dielectric properties of the prepared nanoparticles were studied. The XRD results confirmed the formation of single spinel ferrite structure with crystallite size 9 and 10 nm for x = 0.0 and 0.2 compositions respectively. The lattice parameter (a) increased with increasing Zn concentration. Temperature and frequency dependent electrical and dielectric properties of the prepared ferrites have also been investigated. Our findings show that overall conductivity of Co{sub 0.8}Zn{sub 0.2}Fe{sub 2}O{sub 4} nanoparticle is lower than that of CoFe{sub 2}O{sub 4} and roughly in the range of 10{sup ?11}–10{sup ?7} S cm{sup ?1} depending strongly temperature and frequency owing to the formation of stable electric bonds between the Zn{sup 2+} and Fe{sup 2+} ions, which localizes Fe{sup 2+} charge carriers. The ac conductivity showed a temperature dependent behavior at low frequencies and temperature independent behavior at high frequencies, which is an indication of ionic conductivity. dc conductivity of Co{sub 0.8}Zn{sub 0.2}Fe{sub 2}O{sub 4} nanoparticle are found to obey the Arrhenius plot and can be classified into two regions over with activation energy of 0.113 and 0.163 eV in the ranges of 20–40 °C and 70–120 °C, respectively when CoFe{sub 2}O{sub 4} has an activation energy of 0.245 eV.

  7. Measurement of the B<sub>-c>meson lifetime in the decay B<sub>-c>?J/???

    SciTech Connect (OSTI)

    Aaltonen, T.; Álvarez González, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bisello, D.; Bizjak, I.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Buzatu, A.; Calamba, A.; Calancha, C.; Camarda, S.; Campanelli, M.; Campbell, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Carron, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Chlebana, F.; Cho, K.; Chokheli, D.; Chung, W. H.; Chung, Y. S.; Ciocci, M. A.; Clark, A.; Clarke, C.; Compostella, G.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Crescioli, F.; Cuevas, J.; Culbertson, R.; Dagenhart, D.; d’Ascenzo, N.; Datta, M.; de Barbaro, P.; Dell’Orso, M.; Demortier, L.; Deninno, M.; Devoto, F.; d’Errico, M.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; D’Onofrio, M.; Donati, S.; Dong, P.; Dorigo, M.; Dorigo, T.; Ebina, K.; Elagin, A.; Eppig, A.; Erbacher, R.; Errede, S.; Ershaidat, N.; Eusebi, R.; Farrington, S.; Feindt, M.; Fernandez, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Frank, M. J.; Franklin, M.; Freeman, J. C.; Funakoshi, Y.; Furic, I.; Gallinaro, M.; Garcia, J. E.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Giannetti, P.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Goldschmidt, N.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Hahn, S. R.; Halkiadakis, E.; Hamaguchi, A.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, D.; Hare, M.; Harr, R. F.; Hatakeyama, K.; Hays, C.; Heck, M.; Heinrich, J.; Herndon, M.; Hewamanage, S.; Hocker, A.; Hopkins, W.; Horn, D.; Hou, S.; Hughes, R. E.; Hurwitz, M.; Husemann, U.; Hussain, N.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Khotilovich, V.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. B.; Kim, S. H.; Kim, Y. K.; Kim, Y. J.; Kimura, N.; Kirby, M.; Klimenko, S.; Knoepfel, K.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Krop, D.; Kruse, M.; Krutelyov, V.; Kuhr, T.; Kurata, M.; Kwang, S.; Laasanen, A. T.; Lami, S.; Lammel, S.; Lancaster, M.; Lander, R. L.; Lannon, K.; Lath, A.; Latino, G.; LeCompte, T.; Lee, E.; Lee, H. S.; Lee, J. S.; Lee, S. W.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lin, C.-J.; Lindgren, M.; Lipeles, E.; Lister, A.; Litvintsev, D. O.; Liu, C.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maeshima, K.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, C.; Martínez, M.; Mastrandrea, P.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McFarland, K. S.; McIntyre, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Mondragon, M. N.; Moon, C. S.; Moore, R.; Morello, M. J.; Morlock, J.; Movilla Fernandez, P.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Neubauer, M. S.; Nielsen, J.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagan Griso, S.; Pagliarone, C.; Palencia, E.; Papadimitriou, V.; Paramonov, A. A.; Patrick, J.; Pauletta, G.; Paulini, M.; Paus, C.; Pellett, D. E.; Penzo, A.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Prokoshin, F.; Pranko, A.; Ptohos, F.; Punzi, G.; Rahaman, A.; Ramakrishnan, V.; Ranjan, N.; Redondo, I.; Renton, P.; Rescigno, M.; Riddick, T.; Rimondi, F.; Ristori, L.; Robson, A.; Rodrigo, T.; Rodriguez, T.; Rogers, E.; Rolli, S.; Roser, R.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Safonov, A.; Sakumoto, W. K.

    2013-01-01

    The lifetime of the B<sub>-c> meson is measured using 272 exclusive B<sub>-c>?J/?(?????)?? decays reconstructed in data from proton-antiproton collisions corresponding to an integrated luminosity of 6.7 fb?¹ recorded by the CDF II detector at the Fermilab Tevatron. The lifetime of the B<sub>-c>meson is measured to be <sub>?(B-c>)=0.452±0.048(stat)±0.027(syst) ps. This is the first measurement of the B<sub>-c> meson lifetime in a fully reconstructed hadronic channel, and it agrees with previous results and has comparable precision.

  8. Temperature dependence of the coercive force in Nd sub 4 Fe sub 77 B sub 19

    SciTech Connect (OSTI)

    Eckert, D.; Muller, K.H.; Handstein, A.; Schneider, J. ); Grossinger, R.; Krewenka, R. )

    1990-09-01

    The temperature dependence of coercivity {sub J}H{sub c} of Fe{sub 3}B-based Nd{sub 4}Fe{sub 77}B{sub 19} permanent magnetic materials is analysed. The coercivity of these melt-spun materials vanishes above the Curie temperature of the minor phase Nd{sub 2}Fe{sub 14}B. As well as melt-spun Nd-rich magnets, Nd{sub 4}Fe{sub 77}B{sub 19} magnets show a maximum in the {sub J}H{sub c} versus T curve at low temperatures. The coercivity of these melt-spun materials has a smaller temperature coefficient than sintered Nd-rich NdFeB magnets. The relation of the observed T- dependence of {sub J}H{sub c}, to the anisotropy field H{sub A}(T) of Nd{sub 2}Fe{sub 14}B is discussed.

  9. Analysis of the CO<sub>2sub>-H>2sub>O Chemisorption in Lithium Silicates at Low Temperatures (30-80 °C)

    SciTech Connect (OSTI)

    Alcantar-Vazquez, Brenda; Pfeiffer, Heriberto; Díaz Herrera, Pablo R.; Gonzalez, Alejandro Barrera; Duan, Yuhua

    2015-01-01

    Li<sub>8sub>SiO>6sub> and Li<sub>4sub>SiO>4sub> were synthesized by a solid-state reaction. Then, dynamic and isothermal thermogravimetric water vapor sorption experiments were performed using two carrier gases: N<sub>2sub> and CO<sub>2sub>. Initially, the Li<sub>8sub>SiO>6sub>-H>2sub>O-(N>2sub> or CO<sub>2sub>) systems were analyzed. It was evidenced that Li<sub>8sub>SiO>6sub> can trap water physically and chemically, producing Li-OH superficial species. When CO<sub>2sub> was used as the carrier gas, Li<sub>8sub>SiO>6sub> continued chemisorbing H<sub>2sub>O but CO<sub>2sub> was trapped as well, forming Li<sub>2sub>CO>3sub> and Li<sub>4sub>SiO>4sub> as secondary phases. On the basis of these results, the Li<sub>4sub>SiO>4sub>-H>2sub>O-CO>2sub> system was also analyzed. The experimental results and different theoretical thermodynamic calculations confirmed that Li<sub>8sub>SiO>6sub> can chemisorb 2 moles of CO<sub>2sub> per mole of ceramic at a low temperature range (30-80 °C). Finally, different CO<sub>2sub> chemisorption kinetic experiments were performed to analyze and quantify the trapped CO<sub>2sub>.

  10. Effects of Mg doping on the remarkably enhanced electrochemical performance of Na<sub>3sub>V>2sub>(PO>4sub>)>3sub> cathode materials for sodium ion batteries

    SciTech Connect (OSTI)

    Li, Hui; Yu, Xiqian; Bai, Ying; Wu, Feng; Wu, Chuan; Liu, Liang-Yu; Yang, Xiao-Qing

    2015-01-01

    Na<sub>3sub>V>2-xsub>Mgx(PO>4sub>)>3sub>/C composites with different Mg2+ doping contents (x=0, 0.01, 0.03, 0.05, 0.07 and 0.1) were prepared by a facile sol-gel method. The doping effects on the crystal structure were investigated by XRD, XPS and EXAFS. The results show that low dose doping Mg2+ does not alter the structure of the material, and magnesium is successfully substituted for vanadium site. The Mg doped Na<sub>3sub>V>2-xsub>Mgx(PO>4sub>)>3sub>/C composites exhibit significant improvements on the electrochemistry performances in terms of the rate capability and cycle performance, especially for the Na<sub>3sub>V>1.95sub>Mg>0.05sub>(PO>4sub>)>3sub>/C. For example, when the current density increased from 1 C to 30 C, the specific capacity only decreased from 112.5 mAh g-1 to 94.2 mAh g-1 showing very good rate capability. Moreover, even cycling at a high rate of 20 C, an excellent capacity retention of 81% is maintained from the initial value of 106.4 mAh g-1 to 86.2 mAh g-1 at the 50th cycle. Enhanced rate capability and cycle performance can be attributed to the optimized particle size, structural stability and enhanced ionic and electronic conductivity induced by Mg doping.

  11. Quantum cascade laser investigations of CH{sub 4} and C{sub 2}H{sub 2} interconversion in hydrocarbon/H{sub 2} gas mixtures during microwave plasma enhanced chemical vapor deposition of diamond

    SciTech Connect (OSTI)

    Ma Jie; Cheesman, Andrew; Ashfold, Michael N. R.; Hay, Kenneth G.; Wright, Stephen; Langford, Nigel; Duxbury, Geoffrey; Mankelevich, Yuri A.

    2009-08-01

    CH{sub 4} and C{sub 2}H{sub 2} molecules (and their interconversion) in hydrocarbon/rare gas/H{sub 2} gas mixtures in a microwave reactor used for plasma enhanced diamond chemical vapor deposition (CVD) have been investigated by line-of-sight infrared absorption spectroscopy in the wavenumber range of 1276.5-1273.1 cm{sup -1} using a quantum cascade laser spectrometer. Parameters explored include process conditions [pressure, input power, source hydrocarbon, rare gas (Ar or Ne), input gas mixing ratio], height (z) above the substrate, and time (t) after addition of hydrocarbon to a pre-existing Ar/H{sub 2} plasma. The line integrated absorptions so obtained have been converted to species number densities by reference to the companion two-dimensional (r,z) modeling of the CVD reactor described in Mankelevich et al. [J. Appl. Phys. 104, 113304 (2008)]. The gas temperature distribution within the reactor ensures that the measured absorptions are dominated by CH{sub 4} and C{sub 2}H{sub 2} molecules in the cool periphery of the reactor. Nonetheless, the measurements prove to be of enormous value in testing, tensioning, and confirming the model predictions. Under standard process conditions, the study confirms that all hydrocarbon source gases investigated (methane, acetylene, ethane, propyne, propane, and butane) are converted into a mixture dominated by CH{sub 4} and C{sub 2}H{sub 2}. The interconversion between these two species is highly dependent on the local gas temperature and the H atom number density, and thus on position within the reactor. CH{sub 4}->C{sub 2}H{sub 2} conversion occurs most efficiently in an annular shell around the central plasma (characterized by 1400sub gas}<2200 K), while the reverse transformation C{sub 2}H{sub 2}->CH{sub 4} is favored in the more distant regions where T{sub gas}<1400 K. Analysis of the multistep interconversion mechanism reveals substantial net consumption of H atoms accompanying the CH{sub 4}->C{sub 2}H{sub 2} conversion, whereas the reverse C{sub 2}H{sub 2}->CH{sub 4} process only requires H atoms to drive the reactions; H atoms are not consumed by the overall conversion.

  12. Abnormal thermal conductivity in tetragonal tungsten bronze Ba{sub 6?x}Sr{sub x}Nb{sub 10}O{sub 30}

    SciTech Connect (OSTI)

    Kolodiazhnyi, T. Sakurai, H.; Vasylkiv, O.; Borodianska, H.; Mozharivskyj, Y.

    2014-03-17

    Ba{sub 6?x}Sr{sub x}Nb{sub 10}O{sub 30} solid solution with 0???x???6 crystallizes in centrosymmetric tetragonal “tungsten bronze” structure (space group P4/mbm). We report on the x dependence of thermal conductivity of polycrystalline samples measured in the 2–400?K temperature interval. Substitution of Sr for Ba brings about a significant decrease in thermal conductivity at x???3 accompanied by development of a low-temperature (T???10–30?K) “plateau” region reminiscent of a glass-like compounds. We explain this behaviour based on a size-driven site occupancy and atomic displacement parameters associated with an alkaline earth atomic positions in the title compounds.

  13. Anomalous temperature dependence in valence band spectra: A resonant photoemission study of layered perovskite Sr{sub 2}CoO{sub 4}

    SciTech Connect (OSTI)

    Pandey, Pankaj K.; Choudhary, R. J. Phase, D. M.

    2014-05-05

    Valence band spectra (VBS) and its modification across Curie temperature (T{sub C}) of Sr{sub 2}CoO{sub 4} thin film are studied using resonant photoemission spectroscopy. It is found that VBS mainly consists of hybridized states of Co-3d t{sub 2g}e{sub g} and O-2p; however, Co-3d e{sub g} states show its prominence only in the ferromagnetic temperature regime. Below T{sub C}, spectral weight transfer takes place anomalously from high binding energy (B.E.) region to low B.E. region, signifying the enhanced intermediate or low spin state Co{sup 4+} ions. It is suggested that spin-lattice coupling and many-body effects in Sr{sub 2}CoO{sub 4} derived from the strong electron correlations lead to such temperature dependence of VBS.

  14. La??<sub>xSrx>CuO? superconductor nanowire devices

    SciTech Connect (OSTI)

    Litombe, N. E. [Harvard Univ., Cambridge, MA (United States); Brookhaven National Lab. (BNL), Upton, NY (United States); Bollinger, A. T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hoffman, J. E. [Harvard Univ., Cambridge, MA (United States); Bozovic, I. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2014-11-01

    La??<sub>xSrx>CuO? nanowire devices have been fabricated and characterized using electrical transport measurements. Nanowires with widths down to 80 nm are patterned using high-resolution electron beam lithography. However, the narrowest nanowires show incomplete superconducting transitions with some residual resistance at T = 4 K. Here, we report on refinement of the fabrication process to achieve narrower nanowire devices with complete superconducting transitions, opening the path to the study of novel physics arising from dimension-limited superconductivity on the nanoscale.

  15. La??<sub>xSrx>CuO? superconductor nanowire devices

    SciTech Connect (OSTI)

    Litombe, N. E.; Bollinger, A. T.; Hoffman, J. E.; Bozovic, I.

    2014-07-02

    La??<sub>xSrx>CuO? nanowire devices have been fabricated and characterized using electrical transport measurements. Nanowires with widths down to 80 nm are patterned using high-resolution electron beam lithography. However, the narrowest nanowires show incomplete superconducting transitions with some residual resistance at T = 4 K. Here, we report on refinement of the fabrication process to achieve narrower nanowire devices with complete superconducting transitions, opening the path to the study of novel physics arising from dimension-limited superconductivity on the nanoscale.

  16. Low NO.sub.x multistage combustor

    DOE Patents [OSTI]

    Becker, Frederick E. (Reading, MA); Breault, Ronald W. (Newington, NH); Litka, Anthony F. (Hanover, MA); McClaine, Andrew W. (Lexington, MA); Shukla, Kailash (Boxborough, MA)

    2000-01-01

    A high efficiency, Vortex Inertial Staged Air (VIStA) combustor provides ultra-low NO.sub.X production of about 20 ppmvd or less with CO emissions of less than 50 ppmvd, both at 3% O.sub.2. Prompt NO.sub.X production is reduced by partially reforming the fuel in a first combustion stage to CO and H.sub.2. This is achieved in the first stage by operating with a fuel rich mixture, and by recirculating partially oxidized combustion products, with control over stoichiometry, recirculation rate and residence time. Thermal NO.sub.X production is reduced in the first stage by reducing the occurrence of high temperature combustion gas regions. This is achieved by providing the first stage burner with a thoroughly pre-mixed fuel/oxidant composition, and by recirculating part of the combustion products to further mix the gases and provide a more uniform temperature in the first stage. In a second stage combustor thermal NO.sub.X production is controlled by inducing a large flow of flue gas recirculation in the second stage combustion zone to minimize the ultimate temperature of the flame. One or both of the first and second stage burners can be cooled to further reduce the combustion temperature and to improve the recirculation efficiency. Both of these factors tend to reduce production of NO.sub.X.

  17. Evaluating sub-national building-energy efficiency policy options under uncertainty: Efficient sensitivity testing of alternative climate, technolgical, and socioeconomic futures in a regional intergrated-assessment model.

    SciTech Connect (OSTI)

    Scott, Michael J.; Daly, Don S.; Zhou, Yuyu; Rice, Jennie S.; Patel, Pralit L.; McJeon, Haewon C.; Kyle, G. Page; Kim, Son H.; Eom, Jiyong; Clarke, Leon E.

    2014-05-01

    Improving the energy efficiency of the building stock, commercial equipment and household appliances can have a major impact on energy use, carbon emissions, and building services. Subnational regions such as U.S. states wish to increase their energy efficiency, reduce carbon emissions or adapt to climate change. Evaluating subnational policies to reduce energy use and emissions is difficult because of the uncertainties in socioeconomic factors, technology performance and cost, and energy and climate policies. Climate change may undercut such policies. Assessing these uncertainties can be a significant modeling and computation burden. As part of this uncertainty assessment, this paper demonstrates how a decision-focused sensitivity analysis strategy using fractional factorial methods can be applied to reveal the important drivers for detailed uncertainty analysis.

  18. Scaling of Dynamic Spin Correlations in BaCu<sub>2sub>(Si>0.5sub>Ge>0.5sub>)>2sub>O>7sub>

    SciTech Connect (OSTI)

    Zheludev, Andrey I; Masuda, T.; Dhalenne, G.; Revcolevschi, A.; Frost, C.; Perring, T. G.

    2007-01-01

    The magnetic dynamic structure factor of the one-dimensional S=1/2 chain system BaCu{sub 2}(Si{sub 0.5}Ge{sub 0.5}){sub 2}O{sub 7} is studied in a wide range of energy transfers and temperatures. Contrary to previous erroneous reports [T. Masuda et al., Phys. Rev. Lett. 93, 077206 (2004)], the scaling properties observed in the range 0.5-25 meV are found to be fully consistent with expectations for a Luttinger spin liquid. At higher energies, a breakdown of scaling laws is observed and attributed to lattice effects. The results are complementary to those found in literature for other S=1/2 chain compounds, such as KCuF{sub 3} and Cu benzoate.

  19. Pressure dependence of the monoclinic phase in (1–x)Pb(Mg<sub>1/3sub>Nb>2/3sub>)O>3sub>-xPbTiO? solid solutions

    SciTech Connect (OSTI)

    Ahart, Muhtar; Sinogeikin, Stanislav; Shebanova, Olga; Ikuta, Daijo; Ye, Zuo-Guang; Mao, Ho-kwang; Cohen, R. E.; Hemley, Russell J.

    2012-12-26

    We combine high-pressure x-ray diffraction, high-pressure Raman scattering, and optical microscopy to investigate a series of (1–x)Pb(Mg<sub>1/3sub>Nb>2/3sub>)O>3sub>-xPbTiO? (PMN-xPT) solid solutions (x=0.2, 0.3, 0.33, 0.35, 0.37, 0.4) in diamond anvil cells up to 20 GPa at 300 K. The Raman spectra show a peak centered at 380 cm?¹ starting above 6 GPa for all samples, in agreement with previous observations. X-ray diffraction measurements are consistent with this spectral change indicating a structural phase transition; we find that the triplet at the pseudocubic (220) Bragg peak merges into a doublet above 6 GPa. Our results indicate that the morphotropic phase boundary region (x=0.33–0.37) with the presence of monoclinic symmetry persists up to 7 GPa. The pressure dependence of ferroelectric domains in PMN-0.32PT single crystals was observed using a polarizing optical microscope. The domain wall density decreases with pressure and the domains disappear at a modest pressure of 3 GPa. We propose a pressure-composition phase diagram for PMN-xPT solid solutions.

  20. Molecular beam epitaxial growth and characterization of Bi{sub 2}Se{sub 3}/II-VI semiconductor heterostructures

    SciTech Connect (OSTI)

    Chen, Zhiyi Zhao, Lukas; Krusin-Elbaum, Lia; Garcia, Thor Axtmann; Tamargo, Maria C.; Hernandez-Mainet, Luis C.; Deng, Haiming

    2014-12-15

    Surfaces of three-dimensional topological insulators (TIs) have been proposed to host quantum phases at the interfaces with other types of materials, provided that the topological properties of interfacial regions remain unperturbed. Here, we report on the molecular beam epitaxy growth of II-VI semiconductor–TI heterostructures using c-plane sapphire substrates. Our studies demonstrate that Zn{sub 0.49}Cd{sub 0.51}Se and Zn{sub 0.23}Cd{sub 0.25}Mg{sub 0.52}Se layers have improved quality relative to ZnSe. The structures exhibit a large relative upward shift of the TI bulk quantum levels when the TI layers are very thin (?6nm), consistent with quantum confinement imposed by the wide bandgap II-VI layers. Our transport measurements show that the characteristic topological signatures of the Bi{sub 2}Se{sub 3} layers are preserved.

  1. Measurement of the neutron F<sub>2sub> structure function via spectator tagging with CLAS

    SciTech Connect (OSTI)

    Baillie, N.; Tkachenko, S.; Zhang, J.; Bosted, P.; Bültmann, S.; Christy, M. E.; Fenker, H.; Griffioen, K. A.; Keppel, C. E.; Kuhn, S. E.; Melnitchouk, W.; Tvaskis, V.; Adhikari, K. P.; Adikaram, D.; Aghasyan, M.; Amaryan, M. J.; Anghinolfi, M.; Arrington, J.; Avakian, H.; Baghdasaryan, H.; Battaglieri, M.; Biselli, A. S.; Branford, D.; Briscoe, W. J.; Brooks, W. K.; Burkert, V. D.; Carman, D. S.; Celentano, A.; Chandavar, S.; Charles, G.; Cole, P. L.; Contalbrigo, M.; Crede, V.; D’Angelo, A.; Daniel, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Deur, A.; Dey, B.; Djalali, C.; Dodge, G.; Domingo, J.; Doughty, D.; Dupre, R.; Dutta, D.; Ent, R.; Egiyan, H.; El Alaoui, A.; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Fradi, A.; Gabrielyan, M. Y.; Gevorgyan, N.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Gohn, W.; Golovatch, E.; Gothe, R. W.; Graham, L.; Guegan, B.; Guidal, M.; Guler, N.; Guo, L.; Hafidi, K.; Heddle, D.; Hicks, K.; Holtrop, M.; Hungerford, E.; Hyde, C. E.; Ilieva, Y.; Ireland, D. G.; Ispiryan, M.; Isupov, E. L.; Jawalkar, S. S.; Jo, H. S.; Kalantarians, N.; Khandaker, M.; Khetarpal, P.; Kim, A.; Kim, W.; King, P. M.; Klein, A.; Klein, F. J.; Klimenko, A.; Kubarovsky, V.; Kuleshov, S. V.; Kvaltine, N. D.; Livingston, K.; Lu, H. Y.; MacGregor, I. J. D.; Mao, Y.; Markov, N.; McKinnon, B.; Mineeva, T.; Morrison, B.; Moutarde, H.; Munevar, E.; Nadel-Turonski, P.; Ni, A.; Niccolai, S.; Niculescu, I.; Niculescu, G.; Osipenko, M.; Ostrovidov, A. I.; Pappalardo, L.; Park, K.; Park, S.; Pasyuk, E.; Anefalos Pereira, S.; Pisano, S.; Pozdniakov, S.; Price, J. W.; Procureur, S.; Prok, Y.; Protopopescu, D.; Raue, B. A.; Ricco, G.; Rimal, D.; Ripani, M.; Rosner, G.; Rossi, P.; Sabatié, F.; Saini, M. S.; Salgado, C.; Schott, D.; Schumacher, R. A.; Seder, E.; Sharabian, Y. G.; Sober, D. I.; Sokhan, D.; Stepanyan, S.; Stepanyan, S. S.; Stoler, P.; Strauch, S.; Taiuti, M.; Tang, W.; Ungaro, M.; Vineyard, M. F.; Voutier, E.; Watts, D. P.; Weinstein, L. B.; Weygand, D. P.; Wood, M. H.; Zana, L.; Zhao, B.

    2012-04-01

    We report on the first measurement of the F<sub>2sub> structure function of the neutron from semi-inclusive scattering of electrons from deuterium, with low-momentum protons detected in the backward hemisphere. Restricting the momentum of the spectator protons to ?< 100 MeV and their angles to ?> 100 degrees relative to the momentum transfer allows an interpretation of the process in terms of scattering from nearly on-shell neutrons. The F<sub>2sub>n data collected cover the nucleon resonance and deep-inelastic regions over a wide range of x for 0.65 < Q2 < 4.52 GeV2, with uncertainties from nuclear corrections estimated to be less than a few percent. These measurements provide the first determination of the neutron to proton structure function ratio F<sub>2sub>n/F>2sub>p at 0.2 ?< x ?< 0.8, essentially free of nuclear corrections.

  2. Structure determination of {alpha}-La{sub 6}W{sub 2}O{sub 15}

    SciTech Connect (OSTI)

    Chambrier, M-H.; Ibberson, R.M.; Goutenoire, F.

    2010-06-15

    The structure of the high temperature alpha form of La{sub 6}W{sub 2}O{sub 15} has been determined ab-initio from high temperature laboratory X-ray and neutron time-of-flight data. This tungstate crystallizes in the non-centrosymmetric orthorhombic space group (No. 20) C222{sub 1}, with Z=2, a=12.6250(2) A, b=9.1875(1) A, c=5.9688(1) A. The structure comprises [O{sub 2}La{sub 3}] infinite ribbons and is better described by the structural formula [O{sub 2}La{sub 3}]{sub 2}[WO{sub 5.5}]{sub 2}. Using this description we can understand the strong structural similarity of the present compound with compounds of the general composition BiM{sub 2}AO{sub 6} (M=Cu, Mg, Zn, Mn, Cd, Ca, Pb; A=P, As, V) described as [O{sub 2}M{sub 2}Bi][AO{sub 4}]. The [WO{sub 5.5}] entity implies oxygen disorder in the material. - Graphical abstract: Projection of the polyhedra around the tungsten atom. Atoms labelled in grey are occupied at 50%. Short oxygen-oxygen distances are marked. The polyhedra represents WO{sub 5.5} that is related to the structural unit W{sub 2}O{sub 11} unit. Alpha-La{sub 6}W{sub 2}O{sub 15} could be described as [O{sub 2}La{sub 3}]{sub 2}[WO{sub 5.5}]{sub 2}.

  3. Study of microstructure, dielectric and ferromagnetic properties of the (1-x)Ba{sub 0.95}Sr{sub 0.05}TiO{sub 3}-(x)CoFe{sub 1.8}Mn{sub 0.2}O{sub 4} multiferroic composites

    SciTech Connect (OSTI)

    Sharma, Richa; Tandon, R. P.

    2015-05-15

    In the present work, (1-x)Ba{sub 0.95}Sr{sub 0.05}TiO{sub 3}-(x)CoFe{sub 1.8}Mn{sub 0.2}O{sub 4} composites are prepared by standard solid state reaction method. The X-ray diffraction measurement of the composites shows that both the phases coexist in the composite, individually. The morphology of the composites were examined by field emission scanning electron microscopy and reveals homogeneous microstructure with two types of grains, smaller grains of the Ba{sub 0.95}Sr{sub 0.05}TiO{sub 3} (BST) and bigger grains of the CoFe{sub 1.8}Mn{sub 0.2}O{sub 4} (CFM). The dielectric studies show that all the composites exhibit dispersion in the lower frequency region attributable to the interfacial polarization. In addition, at lower frequencies, the dielectric constant (?´) is found to increase with increase in CFM content in the composites. The ferromagnetic properties of the composites improve with the increase in the CFM content.

  4. The new Hg-rich barium indium mercurides BaIn{sub x}Hg{sub 7?x} (x=3.1) and BaIn{sub x}Hg{sub 11?x} (x=0–2.8)

    SciTech Connect (OSTI)

    Wendorff, Marco; Schwarz, Michael; Röhr, Caroline

    2013-07-15

    The title compounds BaIn{sub x}Hg{sub 7?x} (x=3.1(1)) and BaIn{sub x}Hg{sub 11?x} (x=0–2.8) were synthesized from stoichiometric ratios of the elements in Ta crucibles. Their crystal structures have been determined using single crystal X-ray data. BaIn{sub x}Hg{sub 7?x} (x=3.1(1)) crystallizes in a new structure type (orthorhombic, oC16, space group Cmmm: a=512.02(1), b=1227.68(3), c=668.61(2) pm, Z=2, R1=0.0311). In the structure, the atoms of the three crystallographically different mixed In/Hg positions form planar nets of four-, six- and eight-membered rings. These nets are shifted against each other such that the four-membered rings form empty distorted cubes. The cubes are connected via common edges, corners and folded ladders, which are also found in BaIn{sub 2}/BaHg{sub 2} (KHg{sub 2} structure type) and BaIn (?-NaHg type). The Ba atoms are centered in the eight-membered rings and exhibit an overall coordination number of 20. The [BaM{sub 20}] polyhedra and twice as many distorted [M{sub 8}] cubes tesselate the space. BaIn{sub 2.8}Hg{sub 8.2} (cubic, cP36, space group Pm3{sup ¯}m, a=961.83(1) pm, Z=3, R1=0.0243) is the border compound of the phase width BaIn{sub x}Hg{sub 11?x} of the rare BaHg{sub 11} structure type. In the structure, ideal [M{sub 8}] cubes (at the corners of the unit cell) and BaM{sub 20} polyhedra (at the edges of the unit cell) represent the building blocks comparable to the other new In mercuride. In accordance with the increased In/Hg content, additional M-pure regions appear: the center of the unit cell contains a huge [Hg(1)M(2){sub 12}M(3,4){sub 32}] polyhedron, a Hg-centered cuboctahedron of In/Hg atoms surrounded by a capped cantellated cube of 32 additional M atoms. For both structure types, the bonding situation and the ‘coloring’, i.e. the In/Hg distribution of the polyanionic network, are discussed considering the different sizes of the atoms and the charge distribution (Bader AIM charges), which have been calculated within the framework of FP-LAPW density functional theory. - Graphical abstract: BaIn{sub 2.6}Hg{sub 4.4}: distorted cubes [(In/Hg){sub 8}] (green, like in BaHg{sub 11}), folded ladders (violet, like in BaIn, BaHg{sub 2} and BaIn{sub 2}) and Ba coordination polyhedra [Ba(In/Hg){sub 20}] (blue, like in BaHg{sub 11}). - Highlights: • The Hg-rich In-mercuride BaIn{sub 3.1}Hg{sub 3.9} crystallizes with a singular structure type. • The phase width of the BaHg{sub 11} structure in BaIn{sub x}Hg{sub 11-x} ends at x=2.8. • The relations of both compounds with other alkaline-earth mercurides are outlined. • The Hg/In coloring of the polyanion is discussed considering the structure features. • Bonding aspects are explored using band structure calculations.

  5. Synthesis of low loss, thermally stable Ce{sub x}Y{sub 1-x}TiTaO{sub 6} microwave ceramics

    SciTech Connect (OSTI)

    Padma Kumar, H.; John, Annamma [Dielectric Materials Research Laboratory, Department of Physics, St. John's College, Anchal, Kollam District, Kerala 691306 (India); Vijayakumar, C. [Department of Physics, Mar Ivanios College, Nalanchira, Thiruvananthapuram, Kerala 695015 (India); Thomas, J.K. [Electronic Materials Research Laboratory, Department of Physics, Mar Ivanios College, Nalanchira, Thiruvananthapuram, Kerala 695015 (India); Varma, Manoj Raama [National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram, Kerala 695015 (India); Solomon, Sam [Dielectric Materials Research Laboratory, Department of Physics, St. John's College, Anchal, Kollam District, Kerala 691306 (India)], E-mail: samdmrl@yahoo.com

    2009-02-04

    Ce{sub x}Y{sub 1-x}TiTaO{sub 6} ceramics were prepared through the solid-state ceramic route. The materials were sintered in the range 1520-1580 deg. C. The structure of the system was analyzed by X-ray diffraction and Raman spectroscopic methods. The cell parameters of solid solutions were calculated using the least square method. The microstructure was analyzed using scanning electron microscopy. The dielectric constant ({epsilon}{sub r}), temperature coefficient of resonant frequency ({tau}{sub f}) and the unloaded quality factor (Q{sub u}) are measured in the microwave frequency region using cavity resonator method. The dielectric constant increases with higher concentrations of Ce in the solid solutions. Nearly zero temperature coefficient of resonant frequency ({tau}{sub f}) was obtained for Ce{sub 0.24}Y{sub 0.76}TiTaO{sub 6}. The samples are of high quality factor and are useful electronic materials for microwave applications.

  6. Energy Efficiency in Western Utility Resource Plans: Impacts onRegional Resources Assessment and Support for WGA Policies

    SciTech Connect (OSTI)

    Hopper, Nicole; Goldman, Charles; Schlegal, Jeff

    2006-08-01

    In the aftermath of the consumer price shocks and short-term power shortages of the 2000-01 electricity crisis, policymakers and regulators in Western states are placing increased emphasis on integrated resource planning (IRP), resource adequacy and assessment and a diversified portfolio of resources to meet the needs of electricity consumers. In some states, this has led to a resurgence in state and utility commitments to energy efficiency. Increasing interest in acquiring energy efficiency as a power-system resource is also driven by the desire to dampen high growth rates in electricity demand in some Western states, rapid increases in natural gas prices, concerns about the environmental impacts of electricity generation (e.g. water consumption by power plants, air quality), and the potential of energy efficiency to provide utility bill savings for households and businesses (WGA CDEAC 2006). Recognizing the cost-competitiveness and environmental benefits of energy efficiency, the Western Governor's Association (WGA) has set a high priority for energy efficiency, establishing a goal of reducing projected electricity demand by 20% across the West by 2020 in a policy resolution on Clean and Diversified Energy for the West (WGA 2004). Nationally, the need for improved tracking of demand-side resources in load forecasting is formalized in the North American Electric Reliability Council (NERC)'s recently adopted reliability standards, which utilities and regional reliability organizations will need to comply with (NERC 2005a and 2005b). In this study, we examine the treatment of energy efficiency in recent resource plans issued by fourteen investor-owned utilities (IOUs) in the Western United States and Canada. The goals of this study are to: (1) summarize energy-efficiency resources as represented in a large sample of recent resource plans prepared by Western utilities and identify key issues; (2) evaluate the extent to which the information provided in current resource plans can be used to support region-wide resource assessment and tracking of state/utility progress in meeting the WGA's energy-efficiency goals (WGA 2004); and (3) offer recommendations on information and documentation of energy-efficiency resources that should be included in future resource plans to facilitate comparative review and regional coordination. The scope of this report covers projected electric end-use efficiency investments reported in all Western utility resource plans that were publicly available as of February 2006. While a few utilities included additional demand-side resources, such as demand response, in their plans, we do not report that information. However, many of the issues and recommendations in reference to energy efficiency in this report are relevant to other demand-side resources as well. This report is organized as follows. Section 2 outlines the data sources and approach used in this study and conceptualizes methods and metrics for tracking energy-efficiency resources over time. Section 3 presents results from the review of the utility resource plans. Important issues encountered in reviewing the resource plans are discussed in section 4. Finally, section 5 concludes with recommendations for improving the tracking and reporting of energy efficiency in forthcoming resource plans.

  7. Fermi surface measurements in YBa sub 2 Cu sub 3 O sub 7-x and La sub 1. 874 Sr sub. 126 CuO sub 4

    SciTech Connect (OSTI)

    Howell, R.H.; Sterne, P.A.; Solal, F.; Fluss, M.J. ); Haghighi, H.; Kaiser, J.H.; Rayner, S.L.; West, R.N. ); Liu, J.Z; Shelton, R. ); Kojima, H. ); Kitazawa, K. )

    1991-06-25

    We report new, ultra high precision measurements of the electron-positron momentum spectra of YBa{sub 2}Cu{sub 3}O{sub 7-x} and La{sub 1.874}Sr{sub 126}CuO{sub 4}. The YBCO experiments were performed on twin free, single crystals and show discontinuities with the symmetry of the Fermi surface of the CuO chain bands. Conduction band and underlying features in LSCO share the same symmetry and can only be separated with the aid of LDA calculations. 5 refs., 3 figs.

  8. Observation of the Decay B??D<sub>s(*)+K?l????l>

    SciTech Connect (OSTI)

    del Amo Sanchez, P.; Lees, J. P.; Poireau, V.; Prencipe, E.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Battaglia, M.; Brown, D. N.; Hooberman, B.; Kerth, L. T.; Kolomensky, Yu. G.; Lynch, G.; Osipenkov, I. L.; Tanabe, T.; Hawkes, C. M.; Watson, A. T.; Koch, H.; Schroeder, T.; Asgeirsson, D. J.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; Khan, A.; Randle-Conde, A.; Blinov, V. E.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Yushkov, A. N.; Bondioli, M.; Curry, S.; Kirkby, D.; Lankford, A. J.; Mandelkern, M.; Martin, E. C.; Stoker, D. P.; Atmacan, H.; Gary, J. W.; Liu, F.; Long, O.; Vitug, G. M.; Campagnari, C.; Hong, T. M.; Kovalskyi, D.; Richman, J. D.; Eisner, A. M.; Heusch, C. A.; Kroseberg, J.; Lockman, W. S.; Martinez, A. J.; Schalk, T.; Schumm, B. A.; Seiden, A.; Winstrom, L. O.; Cheng, C. H.; Doll, D. A.; Echenard, B.; Hitlin, D. G.; Ongmongkolkul, P.; Porter, F. C.; Rakitin, A. Y.; Andreassen, R.; Dubrovin, M. S.; Mancinelli, G.; Meadows, B. T.; Sokoloff, M. D.; Bloom, P. C.; Ford, W. T.; Gaz, A.; Nagel, M.; Nauenberg, U.; Smith, J. G.; Wagner, S. R.; Ayad, R.; Toki, W. H.; Jasper, H.; Karbach, T. M.; Merkel, J.; Petzold, A.; Spaan, B.; Wacker, K.; Kobel, M. J.; Schubert, K. R.; Schwierz, R.; Bernard, D.; Verderi, M.; Clark, P. J.; Playfer, S.; Watson, J. E.; Andreotti, M.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cecchi, A.; Cibinetto, G.; Fioravanti, E.; Franchini, P.; Luppi, E.; Munerato, M.; Negrini, M.; Petrella, A.; Piemontese, L.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Nicolaci, M.; Pacetti, S.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; Zallo, A.; Contri, R.; Guido, E.; Lo Vetere, M.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Tosi, S.; Bhuyan, B.; Prasad, V.; Lee, C. L.; Morii, M.; Adametz, A.; Marks, J.; Schenk, S.; Uwer, U.; Bernlochner, F. U.; Ebert, M.; Lacker, H. M.; Lueck, T.; Volk, A.; Dauncey, P. D.; Tibbetts, M.; Behera, P. K.; Mallik, U.; Chen, C.; Cochran, J.; Crawley, H. B.; Dong, L.; Meyer, W. T.; Prell, S.; Rosenberg, E. I.; Rubin, A. E.; Gao, Y. Y.; Gritsan, A. V.; Guo, Z. J.; Arnaud, N.; Davier, M.; Derkach, D.; Firmino da Costa, J.; Grosdidier, G.; Le Diberder, F.; Lutz, A. M.; Malaescu, B.; Perez, A.; Roudeau, P.; Schune, M. H.; Serrano, J.; Sordini, V.; Stocchi, A.; Wang, L.; Wormser, G.; Lange, D. J.; Wright, D. M.; Bingham, I.; Chavez, C. A.; Coleman, J. P.; Fry, J. R.; Gabathuler, E.; Gamet, R.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; Di Lodovico, F.; Sacco, R.; Sigamani, M.; Cowan, G.; Paramesvaran, S.; Wren, A. C.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Hafner, A.; Alwyn, K. E.; Bailey, D.; Barlow, R. J.; Jackson, G.; Lafferty, G. D.; West, T. J.; Anderson, J.; Cenci, R.; Jawahery, A.; Roberts, D. A.; Simi, G.; Tuggle, J. M.; Dallapiccola, C.; Salvati, E.; Cowan, R.; Dujmic, D.; Fisher, P. H.; Sciolla, G.; Zhao, M.; Lindemann, D.; Patel, P. M.; Robertson, S. H.; Schram, M.; Biassoni, P.; Lazzaro, A.; Lombardo, V.; Palombo, F.; Stracka, S.; Cremaldi, L.; Godang, R.; Kroeger, R.; Sonnek, P.; Summers, D. J.; Nguyen, X.; Simard, M.; Taras, P.; De Nardo, G.; Monorchio, D.; Onorato, G.; Sciacca, C.; Raven, G.; Snoek, H. L.; Jessop, C. P.; Knoepfel, K. J.; LoSecco, J. M.; Wang, W. F.; Corwin, L. A.; Honscheid, K.; Kass, R.; Morris, J. P.; Rahimi, A. M.; Blount, N. L.; Brau, J.; Frey, R.; Igonkina, O.; Kolb, J. A.; Rahmat, R.; Sinev, N. B.; Strom, D.; Strube, J.; Torrence, E.; Castelli, G.; Feltresi, E.; Gagliardi, N.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Ben-Haim, E.; Bonneaud, G. R.; Briand, H.; Calderini, G.; Chauveau, J.; Hamon, O.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Prendki, J.; Sitt, S.; Biasini, M.; Manoni, E.; Rossi, A.; Angelini, C.; Batignani, G.; Bettarini, S.; Carpinelli, M.; Casarosa, G.; Cervelli, A.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Neri, N.; Paoloni, E.; Rizzo, G.; Walsh, J. J.; Lopes Pegna, D.; Lu, C.; Olsen, J.; Smith, A. J. S.; Telnov, A. V.; Anulli, F.; Baracchini, E.; Cavoto, G.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Li Gioi, L.; Mazzoni, M. A.; Piredda, G.; Renga, F.; Hartmann, T.; Leddig, T.; Schröder, H.; Waldi, R.; Adye, T.; Franek, B.; Olaiya, E. O.; Wilson, F. F.; Emery, S.; Hamel de Monchenault, G.; Vasseur, G.; Yèche, Ch.; Zito, M.; Allen, M. T.; Aston, D.; Bard, D. J.; Bartoldus, R.; Benitez, J. F.; Cartaro, C.; Convery, M. R.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Field, R. C.; Franco Sevilla, M.; Fulsom, B. G.; Gabareen, A. M.; Graham, M. T.; Grenier, P.; Hast, C.; Innes, W. R.

    2011-07-22

    We report the observation of the decay B??D<sub>s(*)+K?l??¯l> based on 342fb?¹ of data collected at the ?(4S) resonance with the BABAR detector at the PEP-II e?e? storage rings at SLAC. A simultaneous fit to three D+s decay chains is performed to extract the signal yield from measurements of the squared missing mass in the B meson decay. We observe the decay B??D<sub>s(*)+K?l??¯l> with a significance greater than 5 standard deviations (including systematic uncertainties) and measure its branching fraction to be B(B??D<sub>s(*)+K?l??¯l>)=[6.13+1.04<sub>-1.03sub>(stat)±0.43(syst)±0.51(B(D<sub>s>))]×10??, where the last error reflects the limited knowledge of the D<sub>s> branching fractions.

  9. Investigation of the phase equilibria and phase transformations associated with the Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub y} superconductor

    SciTech Connect (OSTI)

    Holesinger, T.

    1993-12-09

    The solid solution region and reaction kinetics of the Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub y} (2212) superconductor were examined as a function of temperature and oxygen partial pressure. Crystallization studies from the glassy and molten states were undertaken to determine the phase transformation and kinetics associated with the formation of 2212 and other competing phases. Crystallization of nominal 2212 glasses was found to proceed in two steps with the formation of Bi{sub 2}Sr{sub 2{minus}x}Ca{sub x}CuO{sub y} (2201) and Cu{sub 2}O followed by Bi{sub 2}Sr{sub 3{minus}x}Ca{sub x}O{sub y}, CaO, and SrO. The 2212 phase converts from the 2201 phase with increasing temperatures. However, its formation below 800 C was kinetically limited. At 800 C and above, a nearly full conversion to the 2212 phase was achieved after only one minute although considerably longer anneal times were necessary for the system to reach equilibrium. In low oxygen partial pressures, the solidus is reduced to approximately 750 C. Solidification studies revealed an eutectic structure separating the incongruently melting 2212/2201 phases at high oxygen partial pressures from the congruently melting Bi{sub 2}Sr{sub 3{minus}x}Ca{sub x}O{sub y} (23x) and Bi{sub 2}Sr{sub 2{minus}x}Ca{sub x}O{sub y} (22x) phases present at low oxygen partial pressures. During solidification in various oxygen partial pressures, the separation of CaO in the melt and the initial crystallization of alkaline-earth cuprates leaves behind a Bi-rich liquid from which it is impossible to form single-phase 2212. Hence, significant amounts of 2201 were also present in these samples. These problems could be reduced by melt processing in inert atmospheres. Bulk 2212 material produced in this manner was found to possess high transition temperatures, high intergranular critical current densities below 20K, and modest critical current densities at 77K.

  10. Extraordinary selectivity of CoMo{sub 3}S{sub 13} chalcogel for C{sub 2}H{sub 6} and CO{sub 2} adsorption.

    SciTech Connect (OSTI)

    Shafaei-Fallah, M.; Rothenberger, Z.; Katsoulidis, A. P.; He, J.; Malliakas, C. D.; Kanatzidis, M. G.

    2011-11-09

    The chalcogel CoMo{sub 3}S{sub 13} is obtained from the reaction of (NH{sub 4}){sub 2}[Mo{sub 3}S{sub 13}] with cobalt acetate in solution. The chalcogel has a BET surface area of 570 m{sup 2} g{sup -1}, and pair distribution function analysis (PDF) and infrared spectroscopy indicate that the [Mo{sub 3}S{sub 13}]{sup 2-} cluster is a building block in the porous network. The CoMo{sub 3}S{sub 13} chalcogel exhibits high selectivity for separating ethane and carbon dioxide from hydrogen and methane.

  11. Structural and optical properties of Ga{sub 2}O{sub 3}:In films deposited on MgO (1 0 0) substrates by MOCVD

    SciTech Connect (OSTI)

    Kong Lingyi; Ma Jin; Luan Caina; Zhu Zhen

    2011-08-15

    Ga{sub 2}O{sub 3}:In films with different indium (In) content x [x=In/(Ga+In) atomic ratio] have been deposited on MgO (1 0 0) substrates by metalorganic chemical vapor deposition (MOCVD). Structural analyses revealed that the film deposited with actual In content (x') of 0.09 was an epitaxial film and the films with x'=0.18 and 0.37 had mixed-phase structures of monoclinic Ga{sub 2}O{sub 3} and bixbyite In{sub 2}O{sub 3}. The absolute average transmittance of the obtained films in the visible region exceeded 95%, and the band gap was in the range of 4.74-4.87 eV. Photoluminescence (PL) measurements were performed at room temperature, in which the visible luminescences were strong and could be seen by the naked eye. The strong emissions in the visible light region were proposed to originate from the gallium vacancies, oxygen deficiencies and other defects in these films. - Graphical abstract: Low magnification XTEM (a), HRTEM (b) and SAED (c) micrographs of the interface area between Ga{sub 1.82}In{sub 0.18}O{sub 3} film and MgO substrate have showed the Ga{sub 1.82}In{sub 0.18}O{sub 3} is an epitaxial film. Highlights: > Ga{sub 1.82}In{sub 0.18}O{sub 3} epitaxial film was deposited on MgO(1 0 0) substrate. > The transmittance of the Ga{sub 2}O{sub 3}:In films in the visible region exceeded 95%. > Strong emissions were observed in the photoluminescence measurements of the films.

  12. The (111) Surface of NaAu<sub>2sub>. Structure, Composition, and Stability

    SciTech Connect (OSTI)

    Kwolek, Emma J.; Widmer, Roland; Gröning, Oliver; Deniz, Okan; Walen, Holly; Yuen, Chad D.; Huang, Wenyu; Schlagel, Deborah L.; Wallingford, Mark; Thiel, Patricia A.

    2014-12-17

    The (111) surface of single-crystal NaAu<sub>2sub> is a model for catalytically active, powdered NaAu<sub>2sub>. We prepare and characterize this surface with a broad suite of techniques. Preparation in ultrahigh vacuum consists of the traditional approach of ion bombardment (to remove impurities) and thermal annealing (to restore surface order). Both of these steps cause loss of sodium (Na), and repeated treatments eventually trigger conversion of the surface and near-surface regions to crystalline gold. The bulk has a limited ability to repopulate the surface Na. Under conditions where Na depletion is minimized, electron diffraction patterns are consistent with the bulk-terminated structure, and scanning tunneling microscopy reveals mesa-like features with lateral dimensions of a few tens of nanometers. The tops of the mesas do not possess fine structure characteristic of a periodic lattice, suggesting that the surface layer is disordered under the conditions of these experiments.

  13. The polygallides: Yb{sub 3}Ga{sub 7}Ge{sub 3} and YbGa{sub 4}Ge{sub2}.

    SciTech Connect (OSTI)

    Peter, S. C.; Malliakas, C. D.; Nakotte, H.; Kothapilli, K.; Rayaprol, S.; Schultz, A. J.; Kanatzidis, M. G. (Materials Science Division); ( XSD); (Northwestern Univ.); (Jawaharlal Nehru Centre for Adv. Sci. Res.); (New Mexico State Univ.); (Los Alamos Nat. Lab.); (UGC-DAE Consortium for Sci. Res.)

    2012-03-01

    Yb{sub 3}Ga{sub 7}Ge{sub 3} and YbGa{sub 4}Ge{sub 2} were obtained from reactions of Yb and Ge in excess liquid gallium. The crystal structure of Yb{sub 3}Ga{sub 7}Ge{sub 3} was refined using X-ray and neutron diffraction data on selected single crystals. Yb{sub 3}Ga{sub 7}Ge{sub 3} crystallizes in the monoclinic space group C2/c with lattice constants a = 12.2261(20) {angstrom}, b = 10.7447(20) {angstrom}, c = 8.4754(17) {angstrom} and {beta} = 110.288(30){sup o} (neutron diffraction data). The crystal structure of Yb{sub 3}Ga{sub 7}Ge{sub 3} is an intergrowth of planar layers of YbGa{sub x}Ge{sub y} and puckered layers of (Ge)n. YbGa{sub 4}Ge{sub 2} crystallizes in a modified PuGa{sub 6} structure type in the tetragonal polar space group I4cm with lattice constants a = b = 5.9874(6) {angstrom} and c = 15.1178(19) {angstrom}. The structure of YbGa{sub 4}Ge{sub 2} is an intergrowth of puckered Ga layers and puckered Ga{sub x}Ge{sub y} layers with Yb atoms residing within the channels formed by the connection of the two layers. Physical properties, resistivity ({rho}), magnetic susceptibility ({chi}) and specific heat (C) were measured for Yb{sub 3}Ga{sub 7}Ge{sub 3}. No magnetic ordering was observed. It was found that at low temperatures, {rho} varied as T{sup 2} and C{alpha}T, indicating Fermi-liquid regime in Yb{sub 3}Ga{sub 7}Ge{sub 3} at low temperatures.

  14. Stripe-like nanoscale structural phase separation in superconducting BaPb<sub>1-xsub>BixO>3sub>

    SciTech Connect (OSTI)

    Giraldo-Gallo, P.; Zhang, Y.; Parra, C.; Manoharan, H. C.; Beasley, M. R.; Geballe, T. H.; Kramer, M. J.; Fisher, I. R.

    2015-09-16

    The phase diagram of BaPb<sub>1-xsub>BixO>3sub> exhibits a superconducting “dome” in the proximity of a charge density wave phase. For the superconducting compositions, the material coexists as two structural polymorphs. Here we show, via high resolution transmission electron microscopy, that the structural dimorphism is accommodated in the form of partially disordered nanoscale stripes. Identification of the morphology of the nanoscale structural phase separation enables determination of the associated length scales, which we compare to the Ginzburg-Landau coherence length. Thus, we find that the maximum T<sub>c> occurs when the superconducting coherence length matches the width of the partially disordered stripes, implying a connection between the structural phase separation and the shape of the superconducting dome.

  15. Preparation of U.sub.3 O.sub.8

    DOE Patents [OSTI]

    Johnson, David R. (Aiken, SC)

    1980-01-01

    A method is described for the preparation of U.sub.3 O.sub.8 nuclear fuel material by direct precipitation of uranyl formate monohydrate from uranyl nitrate solution. The uranyl formate monohydrate precipitate is removed, dried and calcined to produce U.sub.3 O.sub.8 having a controlled particle size distribution.

  16. Fluorocarbon assisted atomic layer etching of SiO<sub>2sub> and Si using cyclic Ar/C<sub>4sub>F>8sub> and Ar/CHF<sub>3sub> plasma

    SciTech Connect (OSTI)

    Metzler, Dominik; Li, Chen; Engelmann, Sebastian; Bruce, Robert L.; Joseph, Eric A.; Oehrlein, Gottlieb S.

    2015-11-11

    The need for atomic layer etching (ALE) is steadily increasing as smaller critical dimensions and pitches are required in device patterning. A flux-control based cyclic Ar/C<sub>4sub>F>8sub> ALE based on steady-state Ar plasma in conjunction with periodic, precise C<sub>4sub>F>8sub> injection and synchronized plasma-based low energy Ar+ ion bombardment has been established for SiO<sub>2sub>.1 In this work, the cyclic process is further characterized and extended to ALE of silicon under similar process conditions. The use of CHF<sub>3sub> as a precursor is examined and compared to C<sub>4sub>F>8sub>. CHF<sub>3sub> is shown to enable selective SiO<sub>2sub>/Si etching using a fluorocarbon (FC) film build up. Other critical process parameters investigated are the FC film thickness deposited per cycle, the ion energy, and the etch step length. Etching behavior and mechanisms are studied using in situ real time ellipsometry and X-ray photoelectron spectroscopy. Silicon ALE shows less self-limitation than silicon oxide due to higher physical sputtering rates for the maximum ion energies used in this work, ranged from 20 to 30 eV. The surface chemistry is found to contain fluorinated silicon oxide during the etching of silicon. As a result, plasma parameters during ALE are studied using a Langmuir probe and establish the impact of precursor addition on plasma properties.

  17. Investigation on dielectric properties of atomic layer deposited Al{sub 2}O{sub 3} dielectric films

    SciTech Connect (OSTI)

    Y?ld?z, Dilber Esra; Y?ld?r?m, Mert; Gökçen, Muharrem

    2014-05-15

    Al/Al{sub 2}O{sub 3}/p-Si Schottky barrier diodes (SBDs) were fabricated using atomic layer deposition technique in order to investigate dielectric properties of SBDs. For this purpose, admittance measurements were conducted at room temperature between ?1?V and 3?V in the frequency range of 10 kHz and 1?MHz. In addition to the investigation of Al{sub 2}O{sub 3} morphology using atomic force microscope, dielectric parameters; such as dielectric constant (??), dielectric loss (??), dielectric loss tangent (tan??), and real and imaginary parts of dielectric modulus (M? and M?, respectively), were calculated and effect of frequency on these parameters of Al/Al{sub 2}O{sub 3}/p-Si SBDs was discussed. Variations in these parameters at low frequencies were associated with the effect of interface states in low frequency region. Besides dielectric parameters, ac electrical conductivity of these SBDs was also investigated.

  18. Transport and magnetization current in a thin layer of Bi{sub 1.8}Pb{sub 0.4}Sr{sub 2.0}Ca{sub 2.2}Cu{sub 3.0}O{sub y} adjacent to silver sheathing in BSCCO-2223 tapes

    SciTech Connect (OSTI)

    Lelovic, M.; Krishnaraj, P.; Deis, T.

    1995-07-01

    The thin superconducting region next to the silver sheath appears to be the region of high critical current density in BSCCO-2223 tapes. Transport current measurements on Bi{sub 1.8}Pb{sub 0.4}Sr{sub 2.0}Ca{sub 2.2}Cu{sub 3.0}O{sub y} tape at 77 K in a low magnetic field applied parallel to the tape thickness indicate an exponential field dependence [J / J{sub c} {proportional_to} exp (- B / B{sub 0})] for transport currents. Magnetic hysteresis was measured in a 10-{mu}m-thick layer of superconductor near the silver sheath as a function of temperature, intensity, and orientation of applied field with respect to the tape. The characteristic field for full penetration depth, B*, for a superconducting slab was found to have a power law dependence on temperature. Magnetization currents as a function of temperature and applied field oriented parallel to the tape thickness, J{sub c,m}(B,T), were determined from the magnetization loop width with a Bean- model expression adapted for an orthorhombic sample. The critical-state model, adjusted for scaling and magnetic relaxation, correlates well with the magnetization current of the thin layer at 77 K.

  19. Structural features and enhanced high-temperature oxygen ion transport in SrFe{sub 1-x}Ta{sub x}O{sub 3-{delta}}

    SciTech Connect (OSTI)

    Markov, Alexey A.; Shalaeva, Elizaveta V.; Tyutyunnik, Alexander P.; Kuchin, Vasily V.; Patrakeev, Mikhail V.; Leonidov, Ilya A.; Kozhevnikov, Victor L.

    2013-01-15

    Structural features, oxygen non-stoichiometry and transport properties are studied in the oxide series SrFe{sub 1-x}Ta{sub x}O{sub 3-{delta}}, where x=0.2, 0.3 and 0.4. X-ray diffraction and electron microscopy data evidence formation of the inhomogeneous materials at x=0.3 and 0.4, which include phase constituents with a cubic perovskite and a double perovskite structure types. The composition, the amount and the typical grain size of the phase inhomogeneities are shown to depend both on doping and oxygen content. The increased oxygen-ion conductivity is observed in oxygen depleted materials, which is explained by the increase in the amount of cubic perovskite-like phase and development of interfacial pathways favorable for enhanced oxygen ion transport. - Graphical abstract: The structural studies, oxygen content and conductivity measurements suggest that oxygen depletion from the double perovskite phase constituent of SrFe{sub 1-x}Ta{sub x}O{sub 3-{delta}} for x>0.2 is accompanied by formation of pathways for fast ion transport. Black-Small-Square Highlights: Black-Right-Pointing-Pointer The double perovskite type regions are shown to exist in SrFe{sub 1-x}Ta{sub x}O{sub 3-{delta}}. Black-Right-Pointing-Pointer The oxygen depletion is accompanied with phase separation. Black-Right-Pointing-Pointer The phase separation favors formation of pathways for enhanced oxygen ion transport.

  20. VO.sub.2 precipitates for self-protected optical surfaces

    DOE Patents [OSTI]

    Gea, Laurence A. (Knoxville, TN); Boatner, Lynn A. (Oak Ridge, TN)

    1999-01-01

    A method for forming crystallographically coherent precipitates of vanadium dioxide in the near-surface region of sapphire and the resulting product is disclosed. Ions of vanadium and oxygen are stoichiometrically implanted into a sapphire substrate (Al.sub.2 O.sub.3), and subsequently annealed to form vanadium dioxide precipitates in the substrate. The embedded VO.sub.2 precipitates, which are three-dimensionally oriented with respect to the crystal axes of the Al.sub.2 O.sub.3 host lattice, undergo a first-order monoclinic-to-tetragonal (and also semiconducting-to-metallic) phase transition at .about.77.degree. C. This transformation is accompanied by a significant variation in the optical transmission of the implanted region and results in the formation of an optically active, thermally "switchable" surface region on Al.sub.2 O.sub.3.

  1. VO{sub 2} precipitates for self-protected optical surfaces

    DOE Patents [OSTI]

    Gea, L.A.; Boatner, L.A.

    1999-03-23

    A method for forming crystallographically coherent precipitates of vanadium dioxide in the near-surface region of sapphire and the resulting product is disclosed. Ions of vanadium and oxygen are stoichiometrically implanted into a sapphire substrate (Al{sub 2}O{sub 3}), and subsequently annealed to form vanadium dioxide precipitates in the substrate. The embedded VO{sub 2} precipitates, which are three-dimensionally oriented with respect to the crystal axes of the Al{sub 2}O{sub 3} host lattice, undergo a first-order monoclinic-to-tetragonal (and also semiconducting-to-metallic) phase transition at ca. 77 C. This transformation is accompanied by a significant variation in the optical transmission of the implanted region and results in the formation of an optically active, thermally ``switchable`` surface region on Al{sub 2}O{sub 3}. 5 figs.

  2. SO<sub>2sub>-Resistant Immobilized Amine Sorbents for CO<sub>2sub> Capture

    SciTech Connect (OSTI)

    Tumuluri, Uma

    2014-01-01

    The solid amine sorbent for CO<sub>2sub> capture process has advantages of simplicity and low operating cost compared to the MEA (monoethanolamine) process. Solid amine sorbents reported so far suffered from either low CO<sub>2sub> capture capacity or low stability in the flue gas environment. This project is aimed at developing a SO<sub>2sub>-resistant solid amine sorbent for capturing CO<sub>2sub> from coal–fired power plants with SCR/FGD which emits SO<sub>2sub>ranging from 15 to 30 ppm and NO ranging from 5 to 10 ppm. The amine sorbent we developed in a previous project degraded rapidly with 65% decrease in the initial capture capacity in presence of 1% SO<sub>2sub>. This amine sorbent was further modified by coating with polyethyleneglycol (PEG) to increase the SO<sub>2sub>-resistance. Polyethylene glycol (PEG) was found to decrease the SO<sub>2sub>-amine interaction, resulting in the decrease in the maximum SO desorption temperature (Tmax ) of amine sorbent. The PEG-coated amine sorbent exhibited higher stability with only 40% decrease in the initial capture capacity compared to un-coated amine sorbents. The cost of the solid amine sorbent developed in this project is estimated to be less than $7.00/lb; the sorbent exhibited CO<sub>2sub> capture capacity more than 2.3 mmol/g. The results of this study provided the scientific basis for further development of SO<sub>2sub>-resistant sorbents.

  3. Structural distortions in the spin-gap regime of the quantum antiferromagnet SrCu{sub 2}(BO{sub 3}){sub 2}

    SciTech Connect (OSTI)

    Vecchini, C.; Adamopoulos, O.; Chapon, L.C.; Lappas, A.; Kageyama, H.; Ueda, Y.; Zorko, A.

    2009-12-15

    We report the first crystallographic study within the low-temperature (<40 K) spin-gap region of the two-dimensional frustrated antiferromagnet SrCu{sub 2}(BO{sub 3}){sub 2}. The crystal system does not deviate from the tetragonal I-42m space group symmetry. However, our high-resolution neutron powder diffraction measurements uncover subtle structural modifications below 34 K, concomitant to the formation of the dimer singlet ground state. Intimate spin-lattice coupling leads to negative thermal expansion of the tetragonal structure, which reflects into particular local lattice adjustments. The extracted structural parameters suggest the reduction of the buckling found in the copper-borate planes and the strengthening of the leading, in-plane intra-dimer superexchange interaction. The observed contraction along the c-axis, associated with the inter-dimer exchange in adjacent layers, indicates the involvement of weaker three-dimensional interactions in the magnetic properties. The rules posed by the crystal symmetry do not preclude Dzyaloshinsky-Moriya interactions, which therefore remain as an important source of spin anisotropy necessary to rationalise the ground state behaviour. - Abstract: We report the first crystallographic study within the low-temperature spin-gap region of the two-dimensional frustrated antiferromagnet SrCu{sub 2}(BO{sub 3}){sub 2}. Subtle spin-lattice coupling was unveiled in the low-temperature region. Display Omitted

  4. Measurement of the ratio of the production cross sections times branching fractions of B<sub>c>± ? J/??±and B± ? J/? K± and B(B<sub>c>±? J/? ?±?±?-/+)/B(B<sub>c>± ? J/? ?±) in pp collisions at ?s = 7 TeV

    SciTech Connect (OSTI)

    Khachatryan, V. [Yerevan Physics Institute (Armenia)

    2015-01-01

    The ratio of the production cross sections times branching fractions (?(B<sub>c>±) B(B<sub>c>± ? J/??±))/(?(B±) B(B± ? J/?K±) is studied in proton-proton collisions at a center-of-mass energy of 7 TeV with the CMS detector at the LHC. The kinematic region investigated requires Ba,sub>c>± and B±mesons with transverse momentum p? > 15 GeV and rapidity |y| < 1.6. The data sample corresponds to an integrated luminosity of 5.1 fb-1. The ratio is determined to be [0.48 ± 0.05 (stat) ± 0.03(syst) ± 0.05 (?B<sub>c>)]% The J/??±?±?-/+ decay mode is also observed in the same data sample. Using a model-independent method developed to measure the efficiency given the presence of resonant behaviour in the three-pion system, the ratio of the branching fractions J/? ?±?±?-/+)/B(B<sub>c>± is measured to be 2.55 ± 0.80(stat) ± 0.33(syst) +0.04<sub>-0.01sub> (?B<sub>c>), consistent with the previous LHCb result.

  5. Structure and ferroelectric studies of (Ba{sub 0.85}Ca{sub 0.15})(Ti{sub 0.9}Zr{sub 0.1})O{sub 3} piezoelectric ceramics

    SciTech Connect (OSTI)

    Venkata Ramana, E.; Mahajan, A.; Graça, M.P.F.; Mendiratta, S.K.; Monteiro, J.M.; Valente, M.A.

    2013-10-15

    Graphical abstract: - Highlights: • (Ba{sub 0.85}Ca{sub 0.15})(Ti{sub 0.9}Zr{sub 0.1})O{sub 3} (BCTZO) ceramic was synthesized by the ceramic method. • In situ XRD and Raman spectra showed the phase transition of BCTZO around 360 K. • The ceramics showed a tunability of 82% at 40 kV cm{sup ?1} electric field. • BCTZO exhibited good quality factor of 111 at microwave frequencies. • Piezoforce microscopy studies indicated the switchability of ferroelectric domains. - Abstract: We have synthesized and studied the structural and ferroelectric properties of lead-free 0.5(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3}–0.5Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3} ceramics in the temperature region of its ferroelectric transition. The synthesized material showed high dielectric constant, low loss and good pyroelectric figure of merit. From the temperature dependent X-ray diffraction measurements, we determined the tricritical point to be in the temperature range of 303–400 K. The dielectric measurements indicate a diffuse ferroelectric phase transition (DPT) around 360 K in agreement with the X-ray measurements. We studied the evolution of Raman spectra with temperature to understand the nature of phase transition in BaTiO{sub 3} (BTO) and the BCTZO. The results indicates that the transition of ferroelectric–paraelectric state is not sharp as in the case of BTO and the polar state persists through the paraelectric state. In general, our study indicates that there are ferroelectric domains of nanometer size beyond the commonly defined transition temperature. The observation of local piezoelectric hysteresis loop indicated the existence of intrinsic ferroelectric property of the ceramic at the nanoscale. The ceramics exhibited electric field tunable dielectric properties with a tunability of 82% at an applied DC field of 40 kV cm{sup ?1}, low dielectric loss of 0.001 and room temperature pyroelectric coefficient of 6 × 10{sup ?8} C cm{sup ?2} K{sup ?1} and the detectivity of 1.9 × 10{sup ?8} C cm{sup ?1} J{sup ?1}; larger than those reported for other BaTiO{sub 3}-based materials. Overall, our results indicate that BCTZO ceramics with coexistence of rhombohedral–tetragonal phases is a promising candidate for lead-free ferroelectric applications.

  6. The polygallides: Yb{sub 3}Ga{sub 7}Ge{sub 3} and YbGa{sub 4}Ge{sub 2}

    SciTech Connect (OSTI)

    Peter, Sebastian C. [Department of Chemistry, Northwestern University, 2145N. Sheridan Road, Evanston, IL 60208 (United States); New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064 (India); Malliakas, Christos D. [Department of Chemistry, Northwestern University, 2145N. Sheridan Road, Evanston, IL 60208 (United States); Nakotte, Heinze; Kothapilli, Karunakar [Physics Department, New Mexico State University, Las Cruces, NM 88003 (United States); Los Alamos Neutron Science Center, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Rayaprol, Sudhindra [UGC-DAE Consortium for Scientific Research, Mumbai Centre, BARC, R-5 Shed, Trombay, Mumbai 400085 (India); Schultz, Arthur J. [X-Ray Science Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Kanatzidis, Mercouri G., E-mail: m-kanatzidis@northwestern.edu [Department of Chemistry, Northwestern University, 2145N. Sheridan Road, Evanston, IL 60208 (United States); Materials Science Division, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2012-03-15

    Yb{sub 3}Ga{sub 7}Ge{sub 3} and YbGa{sub 4}Ge{sub 2} were obtained from reactions of Yb and Ge in excess liquid gallium. The crystal structure of Yb{sub 3}Ga{sub 7}Ge{sub 3} was refined using X-ray and neutron diffraction data on selected single crystals. Yb{sub 3}Ga{sub 7}Ge{sub 3} crystallizes in the monoclinic space group C2/c with lattice constants a=12.2261(20) Angstrom-Sign , b=10.7447(20) Angstrom-Sign , c=8.4754(17) Angstrom-Sign and {beta}=110.288(30) Degree-Sign (neutron diffraction data). The crystal structure of Yb{sub 3}Ga{sub 7}Ge{sub 3} is an intergrowth of planar layers of YbGa{sub x}Ge{sub y} and puckered layers of (Ge){sub n}. YbGa{sub 4}Ge{sub 2} crystallizes in a modified PuGa{sub 6} structure type in the tetragonal polar space group I4cm with lattice constants a=b=5.9874(6) Angstrom-Sign and c=15.1178(19) Angstrom-Sign . The structure of YbGa{sub 4}Ge{sub 2} is an intergrowth of puckered Ga layers and puckered Ga{sub x}Ge{sub y} layers with Yb atoms residing within the channels formed by the connection of the two layers. Physical properties, resistivity ({rho}), magnetic susceptibility ({chi}) and specific heat (C) were measured for Yb{sub 3}Ga{sub 7}Ge{sub 3}. No magnetic ordering was observed. It was found that at low temperatures, {rho} varied as T{sup 2} and C{proportional_to}T, indicating Fermi-liquid regime in Yb{sub 3}Ga{sub 7}Ge{sub 3} at low temperatures. - Graphical abstract: The compounds Yb{sub 3}Ga{sub 7}Ge{sub 3} and YbGa{sub 4}Ge{sub 2} are obtained from reactions of Yb and Ge in excess liquid gallium. Highlights: Black-Right-Pointing-Pointer Yb{sub 3}Ga{sub 7}Ge{sub 3} and YbGa{sub 4}Ge{sub 2} are two new polygallides. Black-Right-Pointing-Pointer The crystal structure of Yb{sub 3}Ga{sub 7}Ge{sub 3} was established using neutron diffraction data. Black-Right-Pointing-Pointer YbGa{sub 4}Ge{sub 2} is one of the rare polar intermetallic compounds. Black-Right-Pointing-Pointer The physical properties of Yb{sub 3}Ga{sub 7}Ge{sub 3} point to a Fermi-liquid regime at low temperature.

  7. Epitaxial YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}}/Sr{sub 2}RuO{sub 4} heterostructures

    SciTech Connect (OSTI)

    Schlom, D.G.; Merritt, B.A.; Madhavan, S. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Materials Science and Engineering] [and others

    1997-09-01

    The anisotropic oxide superconductors YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} and Sr{sub 2}RuO{sub 4} have been epitaxially combined in various ways (c-axis on c-axis, c-axis on a-axis, and a-axis on a-axis) though the use of appropriate substrates. Phase-pure a-axis oriented or c-axis oriented epitaxial Sr{sub 2}RuO{sub 4} films were grown by pulsed laser deposition. YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} films were then grown on both orientations of Sr{sub 2}RuO{sub 4} films and the resulting epitaxy was characterized.

  8. Jumpstarting commercial-scale CO<sub>2sub> capture and storage with ethylene production and enhanced oil recovery in the US Gulf

    SciTech Connect (OSTI)

    Middleton, Richard S.; Levine, Jonathan S.; Bielicki, Jeffrey M.; Viswanathan, Hari S.; Carey, J. William; Stauffer, Philip H.

    2015-04-27

    CO<sub>2sub> capture, utilization, and storage (CCUS) technology has yet to be widely deployed at a commercial scale despite multiple high-profile demonstration projects. We suggest that developing a large-scale, visible, and financially viable CCUS network could potentially overcome many barriers to deployment and jumpstart commercial-scale CCUS. To date, substantial effort has focused on technology development to reduce the costs of CO<sub>2sub> capture from coal-fired power plants. Here, we propose that near-term investment could focus on implementing CO<sub>2sub> capture on facilities that produce high-value chemicals/products. These facilities can absorb the expected impact of the marginal increase in the cost of production on the price of their product, due to the addition of CO<sub>2sub> capture, more than coal-fired power plants. A financially viable demonstration of a large-scale CCUS network requires offsetting the costs of CO<sub>2sub> capture by using the CO<sub>2sub> as an input to the production of market-viable products. As a result, we demonstrate this alternative development path with the example of an integrated CCUS system where CO<sub>2sub> is captured from ethylene producers and used for enhanced oil recovery in the U.S. Gulf Coast region.

  9. Room temperature ferrimagnetism and ferroelectricity in strained, thin films of BiFe <sub>0.5sub> Mn <sub>0.5sub> O <sub>3sub>

    SciTech Connect (OSTI)

    Choi, Eun -Mi; Fix, Thomas; Kursumovic, Ahmed; Kinane, Christy J.; Arena, Darío; Sahonta, Suman -Lata; Bi, Zhenxing; Xiong, Jie; Yan, Li; Lee, Jun -Sik; Wang, Haiyan; Langridge, Sean; Kim, Young -Min; Borisevich, Albina Y.; MacLaren, Ian; Ramasse, Quentin M.; Blamire, Mark G.; Jia, Quanxi; MacManus-Driscoll, Judith L.

    2014-10-14

    Highly strained films of BiFe<sub>0.5sub>Mn>0.5sub>O? (BFMO) grown at very low rates by pulsed laser deposition were demonstrated to exhibit both ferrimagnetism and ferroelectricity at room temperature and above. Magnetisation measurements demonstrated ferrimagnetism (T<sub>C> ~ 600K), with a room temperature saturation moment (M<sub>S>) of up to 90 emu/cc (~ 0.58 ?<sub>B>/f.u) on high quality (001) SrTiO?. X-ray magnetic circular dichroism showed that the ferrimagnetism arose from antiferromagnetically coupled Fe³? and Mn³?. While scanning transmission electron microscope studies showed there was no long range ordering of Fe and Mn, the magnetic properties were found to be strongly dependent on the strain state in the films. The magnetism is explained to arise from one of three possible mechanisms with Bi polarization playing a key role. A signature of room temperature ferroelectricity in the films was measured by piezoresponse force microscopy and was confirmed using angular dark field scanning transmission electron microscopy. The demonstration of strain induced, high temperature multiferroism is a promising development for future spintronic and memory applications at room temperature and above.

  10. Enhancement of methanol electrocatalytic oxidation on platinized WO{sub 3}–TiO{sub 2} composite electrode under visible light irradiation

    SciTech Connect (OSTI)

    Wang, Caiqin [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China); Xinjiang Key Laboratory of Electronic Information Materials and Devices, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011 (China); Jiang, Fengxing [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China); Jiangxi Key Laboratory of Organic Chemistry, Jiangxi Science and Technology Normal University, Nanchang 330013 (China); Zhou, Rong [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China); Xinjiang Key Laboratory of Electronic Information Materials and Devices, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011 (China); Du, Yukou, E-mail: duyk@suda.edu.cn [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China); Xinjiang Key Laboratory of Electronic Information Materials and Devices, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011 (China); Yang, Ping [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China); Wang, Chuanyi, E-mail: cywang@ms.xjb.ac.cn [Xinjiang Key Laboratory of Electronic Information Materials and Devices, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011 (China); Xu, Jingkun, E-mail: xujingkun@tsinghua.org.cn [Jiangxi Key Laboratory of Organic Chemistry, Jiangxi Science and Technology Normal University, Nanchang 330013 (China)

    2013-03-15

    Highlights: ? A ternary composite catalyst of Pt–WO{sub 3}–TiO{sub 2} has been synthesized. ? The introduction of WO{sub 3} extends its absorption edge to visible light region. ? The electrode displays high electrocatalytic activity. ? With visible light irradiation, its electrocatalytic activity increases 70%. - Abstract: A ternary composite catalyst of Pt–WO{sub 3}–TiO{sub 2} has been successfully prepared by a chemical method. The prepared composite was systematically characterized by UV–vis diffuse reflectance absorption spectra (DRS), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM). The electrocatalytic properties of Pt–WO{sub 3}–TiO{sub 2} for methanol oxidation in an alkaline medium were evaluated by the cyclic voltammetry (CV) and chronoamperometry (CA) with or without visible light irradiation. Compared with the pure TiO{sub 2}, the introduction of WO{sub 3} extends its absorption edge to visible light region. Under visible light illumination, the Pt–WO{sub 3}–TiO{sub 2} composite catalyst exhibits higher electrocatalytic activity toward methanol oxidation in comparison with its counterpart, the pure Pt–TiO{sub 2} catalyst.

  11. Case Studies of the ROZ CO<sub>2sub> Flood and the Combined ROZ/MPZ CO<sub>2sub> Flood at the Goldsmith Landreth Unit, Ector County, Texas. Using “Next Generation” CO<sub>2sub> EOR Technologies to Optimize the Residual Oil Zone CO<sub>2sub> Flood

    SciTech Connect (OSTI)

    Trentham, Robert C.; Melzer, L. Stephen; Kuuskraa, Vello; Koperna, George

    2015-06-30

    The technology for CO<sub>2sub> Enhanced Oil Recovery (CO<sub>2sub> EOR) has significantly advanced since the earliest floods were implemented in the 1970s. At least for the Permian Basin region of the U.S., the oil recovery has been now been extended into residual oil zones (ROZs) where the mobile fluid phase is water and immobile phase is oil. But the nature of the formation and fluids within the ROZs has brought some challenges that were not present when flooding the MPZs. The Goldsmith-Landreth project in the Permian Basin was intended to first identify the most pressing issues of the ROZs floods and, secondly, begin to address them with new techniques designed to optimize a flood that commingled the MPZ and the ROZ. The early phase of the research conducted considerable reservoir and fluid characterization work and identified both technical and commercial challenges of producing the enormous quantities of water when flooding the ROZs. It also noted the differing water compositions in the ROZ as compared to the overlying MPZs. A new CO<sub>2sub> gas lift system using a capillary string was successfully applied during the project which conveyed the CO<sub>2sub> to the deeper and differing ROZ reservoir conditions at Goldsmith and added a second capillary string that facilitated applying scale inhibitors to mitigate the scaling tendencies of the mixing ROZ and MPZ formation waters. The project also undertook a reservoir modeling effort, using the acquired reservoir characterization data, to history match both the primary and water flood phases of the MPZ and to establish the initial conditions for a modeling effort to forecast response of the ROZ to CO<sub>2sub> EOR. With the advantage of many profile logs acquired from the operator, some concentration on the original pattern area for the ROZ pilot was accomplished to attempt to perfect the history match for that area. Several optional scenarios for producing the ROZ were simulated seeking to find the preferred mode of producing the two intervals. Finally, the project attempted to document for the first time the production performance of commingled MPZ and ROZ CO<sub>2sub> EOR project at the nearby Seminole San Andres Unit. The analysis shows that over 10,000 bopd can be shown to be coming from the ROZ interval, a zone that would have produced no oil under primary or water flood phases. A similar analysis was done for the GLSAU project illustrating that 2000 bopd of incremental EOR oil is currently being produced. The results of the modeling work would suggest that 800 bopd can be attributed to the ROZ alone at GLSAU.

  12. Metal-semiconductor-transition observed in Bi{sub 2}Ca(Sr, Ba){sub 2}Co{sub 2}O{sub 8+?} single crystals

    SciTech Connect (OSTI)

    Dong, Song-Tao [National Laboratory of Solid State Microstructures and Department of Material Science and Engineering, Nanjing University, Nanjing 210093 (China); Institute of Material Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003 (China); Zhang, Bin-Bin; Zhang, Lun-Yong; Yao, Shu-Hua, E-mail: ybchen@nju.edu.cn, E-mail: shyao@nju.edu.cn; Zhou, Jian; Zhang, Shan-Tao; Gu, Zheng-Bin; Chen, Yan-Feng [National Laboratory of Solid State Microstructures and Department of Material Science and Engineering, Nanjing University, Nanjing 210093 (China); Chen, Y. B., E-mail: ybchen@nju.edu.cn, E-mail: shyao@nju.edu.cn [National Laboratory of Solid State Microstructures and Department of Physics and National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093 (China)

    2014-07-28

    Electrical property evolution of Bi{sub 2}AE{sub 2}Co{sub 2}O{sub 8+?} single crystals (AE?=?Ca, Sr and Ba) is systematically explored. When AE changes from Ca to Ba, the electrical property of Bi{sub 2}Ca{sub 2}Co{sub 2}O{sub 8+?} and Bi{sub 2}Sr{sub 2}Co{sub 2}O{sub 8+?} demonstrates semiconductor-like properties. But Bi{sub 2}Ba{sub 2}Co{sub 2}O{sub 8+?} shows the metallic behavior. Analysis of temperature-dependent resistance substantiates that from metallic Bi{sub 2}Ba{sub 2}Co{sub 2}O{sub 8+?} to semiconductor-like Bi{sub 2}Sr{sub 2}Co{sub 2}O{sub 8+?} can be attributed to Anderson localization. However the semiconductor behaviour of Bi{sub 2}Sr{sub 2}Co{sub 2}O{sub 8+?} and Bi{sub 2}Ca{sub 2}Co{sub 2}O{sub 8+?} is related to electronic correlations effect that is inferred by large negative magnetoresistance (?70%). The theoretical electronic structures and valence X-ray photoemission spectroscopy substantiate that there is a relative large density of state around Fermi level in Bi{sub 2}Ba{sub 2}Co{sub 2}O{sub 8+?} compared with other two compounds. It suggests that Bi{sub 2}Ba{sub 2}Co{sub 2}O{sub 8+?} is more apt to be metal in this material system.

  13. Neutron-scattering evidence for a periodically modulated superconducting phase in the underdoped cuprate La<sub>1.905sub>Ba>0.095sub>CuO>4sub>

    SciTech Connect (OSTI)

    Xu, Zhijun; Stock, C.; Chi, Songxue; Kolesnikov, A. I.; Xu, Guangyong I.; Gu, Genda; Tranquada, J. M.

    2014-10-01

    The role of antiferromagnetic spin correlations in high-temperature superconductors remains a matter of debate. We present inelastic neutron-scattering evidence that gapless spin fluctuations coexist with superconductivity in La<sub>1.905sub>Ba>0.095sub>CuO>4sub>. Furthermore, we observe that both the low-energy magnetic spectral weight and the spin incommensurability are enhanced with the onset of superconducting correlations. We propose that the coexistence occurs through intertwining of spatial modulations of the pair wave function and the antiferromagnetic correlations. This proposal is also directly relevant to sufficiently underdoped La<sub>2-xsub>SrxCuO>4sub> and YBa<sub>2sub>Cu>3sub>O>6+xsub>.

  14. Effect of calcination temperature on electrical properties of Nd{sub 0.7}Ba{sub 0.3}MnO{sub 3}

    SciTech Connect (OSTI)

    Lim, K. P.; Halim, S. A.; Chen, S. K.; Ng, S. W.; Chew, Z. Y.

    2015-04-24

    In this work, Nd{sub 0.7}Ba{sub 0.3}MnO{sub 3} was synthesized via cryo-milling method to investigate the effect of calcination temperature on the structure, microstructure, magnetic and electrical properties. XRD analysis revealed all samples can be indexed to orthorhombic structure systems with Imma space group accompany with some minor phases of Mn{sub 2}O{sub 4} and BaMnO{sub 3}. FESEM analysis confirmed that a slight increase in the grain size from 117.4 nm (600°C), 119.5 nm (700°C), 121.0 nm (800°C), 123.1 nm (900°C) to 138.4 nm (1000°C) was observed when different calcination temperature was applied. Four Point Probe measurements showed that all samples are in paramagnetic insulating region and T{sub MIT} is lower than 20K. Resistivity increase when grain size reduces due to increase of effective grain boundary that weakens the electron hopping process via double exchange mechanism. Beside, a drastic increase of resistivity also observed due to present of minor secondary phase (BaMnO{sub 3}) in sample C9.

  15. Study of the microstructure of plasma sprayed coatings obtained from Al{sub 2}O{sub 3}–13TiO{sub 2} nanostructured and conventional powders

    SciTech Connect (OSTI)

    Góral, A.; ?órawski, W.; Lity?ska-Dobrzy?ska, L.

    2014-10-15

    The microstructure of coatings obtained from nanostructured or conventional Al{sub 2}O{sub 3}–13TiO{sub 2} powders and deposited by plasma spraying technique on low-carbon steel was examined by transmission electron microscopy techniques. The dominating phase in both coatings was ?-Al{sub 2}O{sub 3} phase. It has been observed that the grains of ?-Al{sub 2}O{sub 3} grew in various shapes and sizes, that are particularly visible in the case of coating sprayed from nanostructured powder. The coatings obtained from the fully melted conventional powders exhibited a typical lamellar microstructure, into which the strips of TiO{sub 2} phase were extended. The microstructure of coatings produced from agglomerates of nanostructured particles also revealed the regions consisting of partially melted ?-Al{sub 2}O{sub 3} powders surrounded by the net-like structure formed from fully melted oxides that improved the coating properties. Along with the observed morphology diversity some changes in the chemical composition on the cross sections of obtained coatings have been also noticed. - Highlights: • Plasma sprayed Al{sub 2}O{sub 3}–13TiO{sub 2} coatings reveal diversity of microstructure. • Microstructure of conventional coating was formed from fully melted crushed powders. • Nanostructured coating contains completely and partially melted initial agglomerates.

  16. Effects of coexisting spin disorder and antiferromagnetism on the magnetic behavior of nanostructured (Fe{sub 79}Mn{sub 21}){sub 1?x}Cu{sub x} alloys

    SciTech Connect (OSTI)

    Mizrahi, M. E-mail: cabrera@fisica.unlp.edu.ar; Cabrera, A. F. E-mail: cabrera@fisica.unlp.edu.ar; Desimoni, J.; Stewart, S. J.

    2014-06-07

    We report a magnetic study on nanostructured (Fe{sub 79}Mn{sub 21}){sub 1?x}Cu{sub x} (0.00???x???0.30) alloys using static magnetic measurements. The alloys are mainly composed by an antiferromagnetic fcc phase and a disordered region that displays a spin-glass-like behavior. The interplay between the antiferromagnetic and magnetically disordered phases establishes an exchange anisotropy that gives rise to a loop shift at temperatures below the freezing temperature of moments belonging to the disordered region. The loop shift is more noticeable as the Cu content increases, which also enhances the spin-glass-like features. Further, in the x?=?0.30 alloy the alignment imposed by applied magnetic fields higher than 4 kOe prevail over the configuration determined by the frustration mechanism that characterizes the spin glass-like phase.

  17. Linear and nonlinear optical properties of GaAs/Al{sub x}Ga{sub 1?x}As/GaAs/Al{sub y}Ga{sub 1?y}As multi-shell spherical quantum dot

    SciTech Connect (OSTI)

    Emre Kavruk, Ahmet E-mail: aekavruk@gmail.com; Koc, Fatih; Sahin, Mehmet E-mail: mehsahin@gmail.com

    2013-11-14

    In this work, the optical properties of GaAs/Al{sub x}Ga{sub 1?x}As/GaAs/Al{sub y}Ga{sub 1?y}As multi-shell quantum dot heterostructure have been studied as a function of Al doping concentrations for cases with and without a hydrogenic donor atom. It has been observed that the absorption coefficient strength and/or resonant absorption wavelength can be adjusted by changing the Al content of inner-barrier and/or outer-barrier regions. Besides, it has been shown that the donor atom has an important effect on the control of the electronic and optical properties of the structure. The results have been presented as a function of the Al contents of the inner-barrier x and outer-barrier y regions and probable physical reasons have been discussed.

  18. Dopant spin states and magnetism of Sn{sub 1?x}Fe{sub x}O{sub 2} nanoparticles

    SciTech Connect (OSTI)

    Punnoose, A. Dodge, Kelsey; Reddy, K. M.; Franco, Nevil; Chess, Jordan; Eixenberger, Josh; Beltrán, J. J.; Barrero, C. A.

    2014-05-07

    This work reports detailed investigations of a series of ?2.6?nm sized, Sn{sub 1?x}Fe{sub x}O{sub 2} crystallites with x?=?0–0.10 using Mossbauer spectroscopy, x-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance spectroscopy (EPR), and magnetometry to determine the oxidation state of Fe dopants and their role in the observed magnetic properties. The magnetic moment per Fe ion ? was the largest ?6.48?×?10{sup ?3} ?{sub B} for the sample with the lowest (0.001%) Fe doping, and it showed a rapid downward trend with increasing Fe doping. Majority of the Fe ions are in 3+ oxidation state occupying octahedral sites. Another significant fraction of Fe dopant ions is in 4+ oxidation state and a still smaller fraction might be existing as Fe{sup 2+} ions, both occupying distorted sites, presumably in the surface regions of the nanocrystals, near oxygen vacancies. These studies also suggest that the observed magnetism is not due to exchange coupling between Fe{sup 3+} spins. A more probable role for the multi-valent Fe ions may be to act as charge reservoirs, leading to charge transfer ferromagnetism.

  19. Intrinsic relationship between electronic structures and phase transition of SrBi{sub 2?x}Nd{sub x}Nb{sub 2}O{sub 9} ceramics from ultraviolet ellipsometry at elevated temperatures

    SciTech Connect (OSTI)

    Duan, Z. H.; Jiang, K.; Xu, L. P.; Li, Y. W.; Hu, Z. G. Chu, J. H.

    2014-02-07

    The ferroelectric orthorhombic to paraelectric tetragonal phase transition of SrBi{sub 2?x}Nd{sub x}Nb{sub 2}O{sub 9} (x?=?0, 0.05, 0.1, and 0.2) layer-structured ceramics has been investigated by temperature-dependent spectroscopic ellipsometry. Based on the analysis of dielectric functions from 0 to 500?°C with double Tauc-Lorentz dispersion model, the interband transitions located at ultraviolet region have shown an abrupt variation near the Curie temperature. The changes of dielectric functions are mainly due to the thermal-optical and/or photoelastic effect. Moreover, the characteristic alteration in interband transitions can be ascribed to distortion of NbO{sub 6} octahedron and variation of hybridization between Bi 6s and O 2p states during the structure transformation.

  20. Lasing characteristics of ZrO{sub 2}–Y{sub 2}O{sub 3}–Ho{sub 2}O{sub 3} crystal

    SciTech Connect (OSTI)

    Borik, M A; Lomonova, E E; Kulebyakin, A V; Ushakov, S N; Lyapin, A A; Ryabochkina, P A; Chabushkin, A N

    2013-09-30

    The spectral dependences of the gain cross section of the {sup 5}I{sub 8} ? {sup 5}I{sub 7}, {sup 5}I{sub 7} ? {sup 5}I{sub 8} transition of Ho{sup 3+} ions in the ZrO{sub 2} – 13.6 mol % Y{sub 2}O{sub 3} – 0.4 mol % Ho{sub 2}O{sub 3} crystal are calculated at different relative population inversions using the absorption and luminescence spectra of the {sup 5}I{sub 8} ? {sup 5}I{sub 7} and {sup 5}I{sub 7} ? {sup 5}I{sub 8} transitions of Ho{sup 3+} ions at T=''300'' K. Lasing of these crystals at the {sup 5}I{sub 7} ? {sup 5}I{sub 8} transition is obtained for the first time under pumping by a Tm : YLiF{sub 4} laser (?{sub p} = 1.905 ?m). The lasing wavelength is 2.17 ?m. (lasers)

  1. [NH{sub 3}(CH{sub 2}){sub 2}NH{sub 3}][Co(SO{sub 4}){sub 2}(H{sub 2}O){sub 4}]: Chemical preparation, crystal structure, thermal decomposition and magnetic properties

    SciTech Connect (OSTI)

    Rekik, Walid; Naili, Houcine; Mhiri, Tahar [Laboratoire de l'Etat Solide, Departement de Chimie, Faculte des Sciences de Sfax, BP 802, 3018 Sfax (Tunisia); Bataille, Thierry [Sciences Chimiques de Rennes (CNRS, UMR 6226), Groupe Materiaux Inorganiques: Chimie Douce et Reactivite, Universite de Rennes I, Avenue du General Leclerc, 35042 Rennes Cedex (France)], E-mail: thierry.bataille@univ-rennes1.fr

    2008-10-02

    Cobalt ethylenediammonium bis(sulfate) tetrahydrate, [NH{sub 3}(CH{sub 2}){sub 2}NH{sub 3}][Co(SO{sub 4}){sub 2}(H{sub 2}O){sub 4}], has been synthesised by slow evaporation at room temperature. It crystallises in the triclinic system, space group P1-bar, with the unit cell parameters: a = 6.8033(2), b 7.0705(2), c = 7.2192(3) A, {alpha} = 74.909(2){sup o}, {beta} = 72.291(2){sup o}, {gamma} = 79.167(2){sup o}, Z = 1 and V = 317.16(2) A{sup 3}. The Co(II) atom is octahedrally coordinated by four water molecules and two sulfate tetrahedra leading to trimeric units [Co(SO{sub 4}){sub 2}(H{sub 2}O){sub 4}]. These units are linked to each other and to the ethylenediammonium cations through OW-H...O and N-H...O hydrogen bonds, respectively. The zero-dimensional structure is described as an alternation between cationic and anionic layers along the crystallographic b-axis. The dehydration of the precursor proceeds through three stages leading to crystalline intermediary hydrate phases and an anhydrous compound. The magnetic measurements show that the title compound is predominantly paramagnetic with weak antiferromagnetic interactions.

  2. Transmission Vegetation Management NERC Standard FAC-003-2 Technical

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page| Open Energy Information Serbia-EnhancingEt Al., 2013)OpenEnergyTrail Canyon Geothermal ProjectTransmarkPrepared

  3. Prepared Statement for Mr. Michael P. Mertz Director, NERC Regulatory...

    Broader source: Energy.gov (indexed) [DOE]

    headquartered in New Mexico. I appreciate the opportunity to speak to the topic of future energy systems and addressing the vulnerabilities of our nation's energy...

  4. NERC standards and standards compliance: still a work in progress?

    SciTech Connect (OSTI)

    Lyons, Cristin; Jacobi, Jere; Starkweather, Rick

    2008-04-15

    The August 2003 blackout served as a wake-up call to all of North America. Several years of detailed assessment and planning by transmission governing bodies have provided a method of systematically improving the integrity of the transmission grid, but processes are still evolving. (author)

  5. Property:EIA/861/NercLocation | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History ViewMayo,AltFuelVehicle2 Jump to: navigation, search This is a property of type Boolean.IsoNe

  6. Property:EIA/861/NercMro | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History ViewMayo,AltFuelVehicle2 Jump to: navigation, search This is a property of type

  7. Microsoft PowerPoint - SWL NERC status june 2009.ppt

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines light on darkMicroorganismsnowReport ARM ScienceCORPS OF ENGINEERS

  8. Sandia Energy - North American Electric Reliability Corporation (NERC)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust, High-Throughput Analysis ofSampleLignin-FeastingPreviously

  9. Property:EIA/861/NercErcot | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to: navigation, search PropertyIsoOther Jump to: navigation, search

  10. Property:EIA/861/NercNpcc | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to: navigation, search PropertyIsoOther Jump to: navigation,

  11. NERC Presentation: Accommodating High Levels of Variable Generation,

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterested Parties -Department of EnergyNEW1 NEPAOctober 29, 2010 | Department of

  12. NERC IVGTF Task 1-3 Section 3-1

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  13. Comments of North American Electric Reliability Corporation (NERC) to DOE

    Broader source: Energy.gov (indexed) [DOE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergy A plug-in electric vehicle (PEV)Day-June 22, 2015 |AT&T IncNational Grid'sSmart

  14. Initial results from seismic monitoring at the Aquistore CO<sub>2sub> storage site, Saskatchewan, Canada

    SciTech Connect (OSTI)

    White, D. J.; Roach, L. A.N.; Roberts, B.; Daley, T. M.

    2014-12-31

    The Aquistore Project, located near Estevan, Saskatchewan, is one of the first integrated commercial-scale CO<sub>2sub> storage projects in the world that is designed to demonstrate CO<sub>2sub> storage in a deep saline aquifer. Starting in 2014, CO<sub>2sub> captured from the nearby Boundary Dam coal-fired power plant will be transported via pipeline to the storage site and to nearby oil fields for enhanced oil recovery. At the Aquistore site, the CO<sub>2sub> will be injected into a brine-filled sandstone formation at ~3200 m depth using the deepest well in Saskatchewan. The suitability of the geological formations that will host the injected CO<sub>2sub> has been predetermined through 3D characterization using high-resolution 3D seismic images and deep well information. These data show that 1) there are no significant faults in the immediate area of the storage site, 2) the regional sealing formation is continuous in the area, and 3) the reservoir is not adversely affected by knolls on the surface of the underlying Precambrian basement. Furthermore, the Aquistore site is located within an intracratonic region characterized by extremely low levels of seismicity. This is in spite of oil-field related water injection in the nearby Weyburn-Midale field where a total of 656 million m3 of water have been injected since the 1960`s with no demonstrable related induced seismicity. A key element of the Aquistore research program is the further development of methods to monitor the security and subsurface distribution of the injected CO<sub>2sub>. Toward this end, a permanent areal seismic monitoring array was deployed in 2012, comprising 630 vertical-component geophones installed at 20 m depth on a 2.5x2.5 km regular grid. This permanent array is designed to provide improved 3D time-lapse seismic imaging for monitoring subsurface CO<sub>2sub>. Prior to the onset of CO<sub>2sub> injection, calibration 3D surveys were acquired in May and November of 2013. Comparison of the data from these surveys relative to the baseline 3D survey data from 2012 shows excellent repeatability (NRMS less than 10%) which will provide enhanced monitoring sensitivity to smaller amounts of CO<sub>2sub>. The permanent array also provides continuous passive monitoring for injection-related microseismicity. Passive monitoring has been ongoing since the summer of 2012 in order to establish levels of background seismicity before CO<sub>2sub> injection starts in 2014. Microseismic monitoring was augmented in 2013 by the installation of 3 broadband seismograph stations surrounding the Aquistore site. These surface installations should provide a detection capability of seismic events with magnitudes as low as ~0. Downhole seismic methods are also being utilized for CO<sub>2sub> monitoring at the Aquistore site. Baseline crosswell tomographic images depict details (meters-scale) of the reservoir in the 150-m interval between the observation and injection wells. This level of resolution is designed to track the CO<sub>2sub> migration between the wells during the initial injection period. A baseline 3D vertical seismic profile (VSP) was acquired in the fall of 2013 to provide seismic images with resolution on a scale between that provided by the surface seismic array and the downhole tomography. The 3D VSP was recorded simultaneously using both a conventional array of downhole geophones (60-levels) and an optical fibre system. The latter utilized an optical fiber cable deployed on the outside of the monitor well casing and cemented in place. A direct comparison of these two methodologies will determine the suitability of using the fiber cable for ongoing time-lapse VSP monitoring.

  15. Initial results from seismic monitoring at the aquistore CO<sub>2sub> storage site, Saskatchewan, Canada

    SciTech Connect (OSTI)

    White, D. J. [Geological Survey of Canada, Ottawa (Canada); Roach, L. A.N. [Geological Survey of Canada, Ottawa (Canada); Roberts, B. [Geological Survey of Canada, Ottawa (Canada); Daley, T. M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-12-31

    The Aquistore Project, located near Estevan, Saskatchewan, is one of the first integrated commercial-scale CO<sub>2sub> storage projects in the world that is designed to demonstrate CO<sub>2sub> storage in a deep saline aquifer. Starting in 2014, CO<sub>2sub> captured from the nearby Boundary Dam coal-fired power plant will be transported via pipeline to the storage site and to nearby oil fields for enhanced oil recovery. At the Aquistore site, the CO<sub>2sub> will be injected into a brine-filled sandstone formation at ~3200 m depth using the deepest well in Saskatchewan. The suitability of the geological formations that will host the injected CO<sub>2sub> has been predetermined through 3D characterization using high-resolution 3D seismic images and deep well information. These data show that 1) there are no significant faults in the immediate area of the storage site, 2) the regional sealing formation is continuous in the area, and 3) the reservoir is not adversely affected by knolls on the surface of the underlying Precambrian basement. Furthermore, the Aquistore site is located within an intracratonic region characterized by extremely low levels of seismicity. This is in spite of oil-field related water injection in the nearby Weyburn-Midale field where a total of 656 million m3 of water have been injected since the 1960`s with no demonstrable related induced seismicity. A key element of the Aquistore research program is the further development of methods to monitor the security and subsurface distribution of the injected CO<sub>2sub>. Toward this end, a permanent areal seismic monitoring array was deployed in 2012, comprising 630 vertical-component geophones installed at 20 m depth on a 2.5x2.5 km regular grid. This permanent array is designed to provide improved 3D time-lapse seismic imaging for monitoring subsurface CO<sub>2sub>. Prior to the onset of CO<sub>2sub> injection, calibration 3D surveys were acquired in May and November of 2013. Comparison of the data from these surveys relative to the baseline 3D survey data from 2012 shows excellent repeatability (NRMS less than 10%) which will provide enhanced monitoring sensitivity to smaller amounts of CO<sub>2sub>. The permanent array also provides continuous passive monitoring for injection-related microseismicity. Passive monitoring has been ongoing since the summer of 2012 in order to establish levels of background seismicity before CO<sub>2sub> injection starts in 2014. Microseismic monitoring was augmented in 2013 by the installation of 3 broadband seismograph stations surrounding the Aquistore site. These surface installations should provide a detection capability of seismic events with magnitudes as low as ~0. Downhole seismic methods are also being utilized for CO<sub>2sub> monitoring at the Aquistore site. Baseline crosswell tomographic images depict details (meters-scale) of the reservoir in the 150-m interval between the observation and injection wells. This level of resolution is designed to track the CO<sub>2sub> migration between the wells during the initial injection period. A baseline 3D vertical seismic profile (VSP) was acquired in the fall of 2013 to provide seismic images with resolution on a scale between that provided by the surface seismic array and the downhole tomography. The 3D VSP was recorded simultaneously using both a conventional array of downhole geophones (60-levels) and an optical fibre system. The latter utilized an optical fiber cable deployed on the outside of the monitor well casing and cemented in place. A direct comparison of these two methodologies will determine the suitability of using the fiber cable for ongoing time-lapse VSP monitoring.

  16. Magnetism and superconductivity in U?Pt<sub>xRh>(1–x)sub>C?

    SciTech Connect (OSTI)

    Wakeham, N.; Ni, Ni; Bauer, E. D.; Thompson, J. D.; Tegtmeier, E.; Ronning, F.

    2015-01-01

    We report the phase diagram of the doping series U?Pt<sub>xRh>(1–x)sub>C?, studied through measurements of resistivity, specific heat, and magnetic susceptibility. The Néel temperature of U?Rh?C? of ~ 22 K is suppressed with increasing Pt content, reaching zero temperature close to x = 0.7, where we observed signatures of increased quantum fluctuations. In addition, evidence is presented that the antiferromagnetic state undergoes a spin-reorientation transition upon application of an applied magnetic field. This transition shows non-monotonic behavior as a function of x, peaking at around x = 0.3. Superconductivity is observed for x ? 0.9, with T<sub>c> increasing with increasing x. The reduction in T<sub>c> and increase in residual resistivity with decreasing Pt content is inconsistent with the extension of the Abrikosov-Gor'kov theory to unconventional superconductivity.

  17. THE ORIGIN OF ASTEROID 162173 (1999 JU{sub 3})

    SciTech Connect (OSTI)

    Campins, Humberto [Physics Department, University of Central Florida, P.O. Box 162385, Orlando, FL 32816-2385 (United States); De Leon, Julia [Department of Edaphology and Geology, University of La Laguna, E-38071 Tenerife (Spain); Morbidelli, Alessandro; Gayon-Markt, Julie; Delbo, Marco; Michel, Patrick [Observatoire de la Cote d'Azur, Universite de Nice Sophia Antipolis (UNS), CNRS UMR7293, F-06108 Nice Cedex 2 (France); Licandro, Javier [Instituto de Astrofisica de Canarias (IAC), C/Via Lactea s/n, E-38205 La Laguna (Spain)

    2013-08-01

    Near-Earth asteroid (162173) 1999 JU{sub 3} (henceforth JU{sub 3}) is a potentially hazardous asteroid and the target of the Japanese Aerospace Exploration Agency's Hayabusa-2 sample return mission. JU{sub 3} is also a backup target for two other sample return missions: NASA's OSIRIS-REx and the European Space Agency's Marco Polo-R. We use dynamical information to identify an inner-belt, low-inclination origin through the {nu}{sub 6} resonance, more specifically, the region with 2.15 AU < a < 2.5 AU and i < 8 Degree-Sign . The geometric albedo of JU{sub 3} is 0.07 {+-} 0.01, and this inner-belt region contains four well-defined low-albedo asteroid families (Clarissa, Erigone, Polana, and Sulamitis), plus a recently identified background population of low-albedo asteroids outside these families. Only two of these five groups, the background and the Polana family, deliver JU{sub 3}-sized asteroids to the {nu}{sub 6} resonance, and the background delivers significantly more JU{sub 3}-sized asteroids. The available spectral evidence is also diagnostic; the visible and near-infrared spectra of JU{sub 3} indicate it is a C-type asteroid, which is compatible with members of the background, but not with the Polana family because it contains primarily B-type asteroids. Hence, this background population of low-albedo asteroids is the most likely source of JU{sub 3}.

  18. Criticality Safety Study of UF<sub>6sub>and UO<sub>2sub>F>2sub>in 8-in. Inner Diameter Piping

    SciTech Connect (OSTI)

    Elam, K.R.

    2003-10-07

    The purpose of this report is to provide an evaluation of the criticality safety aspects of using up to 8-in.-inner-diameter (ID) piping as part of a system to monitor the {sup 235}U enrichment in uranium hexafluoride (UF{sub 6}) gas both before and after an enrichment down-blending operation. The evaluated operation does not include the blending stage but includes only the monitors and the piping directly associated with the monitors, which are in a separate room from the blending operation. There are active controls in place to limit the enrichment of the blended UF{sub 6} to a maximum of 5 weight percent (wt%) {sup 235}U. Under normal operating conditions of temperature and pressure, the UF{sub 6} will stay in the gas phase and criticality will not be credible. The two accidents of concern are solidification of the UF{sub 6} along with some hydrofluoric acid (HF) and water or moisture ingress, which would cause the UF{sub 6} gas to react and form a hydrated uranyl fluoride (UO{sub 2}F{sub 2}) solid or solution. Of these two types of accidents, the addition of water and formation of UO{sub 2}F{sub 2} is the most reactive scenario and thus limits related to UO{sub 2}F{sub 2} will bound the limits related to UF{sub 6}. Two types of systems are included in the monitoring process. The first measures the enrichment of the approximately 90 wt% enriched UF{sub 6} before it is blended. This system uses a maximum 4-in.-(10.16-cm-) ID pipe, which is smaller than the 13.7-cm-cylinder-diameter subcritical limit for UO{sub 2}F{sub 2} solution of any enrichment as given in Table 1 of American National Standard ANSI/ANS-8.1.1 Therefore, this system poses no criticality concerns for either accident scenario. The second type of system includes two enrichment monitors for lower-enriched UF{sub 6}. One monitors the approximately 1.5 wt% enriched UF{sub 6} entering the blending process, and the second monitors the approximately 5 wt% enriched UF{sub 6} coming out of the blending process. Both use a maximum 8-in.-(20.32-cm-) ID piping, where the length of the larger ID piping is approximately 9.5 m. This diameter of piping is below the 26.6-cm-cylinder-diameter subcritical limit for 5 wt% enriched UO{sub 2}F{sub 2} solutions as given in Table 6 of ANSI/ANS-8.1. Therefore, for up to 5 wt% enriched UF{sub 6}, this piping does not present a criticality concern for either accident scenario. Calculations were performed to determine the enrichment level at which criticality could become a concern in these 8-in.-ID piping sections. Both unreflected and fully water-reflected conditions were considered.

  19. Final Report: Northeastern Regional Center of the DOE's National Institute for Climatic Change Research

    SciTech Connect (OSTI)

    Davis, Kenneth

    2014-01-14

    Administration of the NERC of NICCR began at Penn State in December of 2005 and ended in December of 2011. During that time, five requests for proposals were released and five rounds of proposals were reviewed, awarded and administered. Throughout this award, 203 pre-proposals have been received by the NERC in five RFPS and 110 full proposals invited. Of the 110 full proposals reviewed, 53 were funded (most in full, some partially) resulting in 51 subcontracts. These awards were distributed among 17 universities and 3 non-governmental research institutes. Full proposals have been received from 29 universities and 5 non-governmental research institutes. Research activities have now been completed.

  20. Oxygen trapped by rare earth tetrahedral clusters in Nd<sub>4sub>FeOS>6sub>: Crystal structure, electronic structure, and magnetic properties

    SciTech Connect (OSTI)

    Lin, Qisheng; Taufour, Valentin; Zhang, Yuemei; Wood, Max; Drtina, Thomas; Bud’ko, Sergey L.; Canfield, Paul C.; Miller, Gordon J.

    2015-05-22

    Single crystals of Nd<sub>4sub>FeOS>6sub> were grown from an Fe-S eutectic solution. Single crystal X-ray diffraction analysis revealed a Nd<sub>4sub>MnOSe>6sub>-type structure (P6<sub>3sub>mc, a = 9.2693(1) Å, c = 6.6650(1) Å, V = 495.94(1) Å3, Z = 2), featuring parallel chains of face-sharing [FeS<sub>6x1/2sub>]4- trigonal antiprisms and interlinked [Nd<sub>4sub>OS>3sub>]4+ cubane-like clusters. Oxygen atoms were found to be trapped by Nd4 clusters in the [Nd4OS3]4+ chains. Structural differences among Nd<sub>4sub>MnOSe>6sub>-type Nd<sub>4sub>FeOS>6sub> and the related La<sub>3sub>CuSiS>7sub>- and Pr<sub>8sub>CoGa>3sub>-type structures have been described. Magnetic susceptibility measurements on Nd<sub>4sub>FeOS>6sub> suggested the dominance of antiferromagnetic interactions at low temperature, but no magnetic ordering down to 2 K was observed. Spin-polarized electronic structure calculations revealed magnetic frustration with dominant antiferromagnetic interactions.

  1. Regional Purchasing

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMassR&D100 Winners * ImpactsandRegarding ConfinementRegional Partnerships

  2. Synthesis, crystal structure and thermal behavior of two hydrated forms of lanthanide phthalates Ln{sub 2}(O{sub 2}+C{sub 6}H{sub 4}-CO{sub 2}){sub 3}(H{sub 2}O) (Ln=Ce, Nd) and Nd{sub 2}(O{sub 2}C-C{sub 6}H{sub 4}-CO{sub 2}){sub 3}(H{sub 2}O){sub 3}

    SciTech Connect (OSTI)

    Pizon, David; Henry, Natacha; Loiseau, Thierry; Roussel, Pascal; Abraham, Francis

    2010-09-15

    New hydrated lanthanide phthalates have been hydrothermally prepared with cerium and neodymium in different reaction media involving water or mixed water-ethanol solvent. The monohydrated Ln{sub 2}(1,2-bdc){sub 3}(H{sub 2}O) (Ln=Ce or Nd) and dihydrated Nd{sub 2}(1,2-bdc){sub 3}(H{sub 2}O){sub 2} forms have been characterized by single-crystal analysis. Their structures consist of infinite inorganic chains of lanthanide-centered polyhedra linked to each other through the phthalate ligands in order to generate mixed organic-inorganic layered structure. The two hydrated structures differ by the number of terminal water species attached to the lanthanide cations, which induce symmetry change from a triclinic (Nd{sub 2}(1,2-bdc){sub 3}(H{sub 2}O){sub 2}) to an orthorhombic (Nd{sub 2}(1,2-bdc){sub 3}(H{sub 2}O){sub 2}) cell for neodymium whereas the cerium-based phase only exists in the monohydrated form, with two distinct symmetries (orthorhombic or triclinic). Structural comparisons with the other members of the lanthanide phthalate series with identical chemical formula are also discussed. Thermal X-ray diffraction experiment indicates that the transformation from dihydrate form into the monohydrated form does not occur during a heating process. - Graphical abstract: New members of the chain-like structures of neodymium phthalates with different hydration states Nd{sub 2}(1,2-bdc){sub 3}(H{sub 2}O){sub x} (x=1 or 2, 1-2bdc=phthalate group) and comparison with cerium-based analogs.

  3. Structure–property relations of orthorhombic [(CH{sub 3}){sub 3}NCH{sub 2}COO]{sub 2}(CuCl{sub 2}){sub 3}·2H{sub 2}O

    SciTech Connect (OSTI)

    Haussühl, Eiken; Schreuer, Jürgen; Wiehl, Leonore; Paulsen, Natalia

    2014-04-01

    Large single crystals of orthorhombic [(CH{sub 3}){sub 3}NCH{sub 2}COO]{sub 2}(CuCl{sub 2}){sub 3}·2H{sub 2}O with dimensions up to 40×40×30 mm{sup 3} were grown from aqueous solutions. The elastic and piezoelastic coefficients were derived from ultrasonic resonance frequencies and their shifts upon variation of pressure, respectively, using the plate-resonance technique. Additionally, the coefficients of thermal expansion were determined between 95 K and 305 K by dilatometry. The elastic behaviour at ambient conditions is dominated by the 2-dimensional network of strong hydrogen bonds within the (001) plane leading to a corresponding pseudo-tetragonal anisotropy of the longitudinal elastic stiffness. The variation of elastic properties with pressure, however, as well as the thermal expansion shows strong deviations from the pseudo-tetragonal symmetry. These deviations are probably correlated with tilts of the elongated tri-nuclear betaine–CuCl{sub 2}–water complexes. Neither the thermal expansion nor the specific heat capacity gives any hint on a phase transition in the investigated temperature range. - Graphical abstract: Single crystal of orthorhombic [(CH{sub 3}){sub 3}NCH{sub 2}COO]{sub 2}(CuCl{sub 2}){sub 3}·2H{sub 2}O. - Highlights: • Large single crystals (40 ×40 ×30 mm{sup 3}) of [(CH{sub 3}){sub 3}NCH{sub 2}COO]{sub 2}(CuCl{sub 2}){sub 3}·2H{sub 2}O were grown. • The elastic and piezoelastic coefficients were derived from ultrasonic resonance frequencies. • Thermal expansion (95 K–305 K) and heat capacity (113 K–323 K) were determined. • The orthorhombic structure shows pseudo-tetragonal elastic anisotropy at ambient conditions. • The crystal structure is stable in the investigated range (1–1600 bar, 95–303 K)

  4. Relevant Studies for NERC’s Analysis of EPA’s Clean Power Plan 111(d) Compliance

    SciTech Connect (OSTI)

    Ahlstrom, Mark; Smith, Charlie; Piwko, Dick; Lew, Debra; Bloom, Aaron; Mai, Trieu; Clark, Kara; Milligan, Michael

    2015-06-12

    The purpose of this paper is to describe multiple studies of wind and solar integration that have found CO2 reductions of approximately 30%. These studies can be viewed in several ways, including as viable paths to compliance with the EPA rule, alternative “bookend cases” to compare to compliance based largely on natural gas, or something in between. The studies in this paper represent a body of work that can help inform the public discussion surrounding the cost and reliability impacts of complying with the proposed EPA CPP.

  5. PlanetEarthWinter2002--www.nerc.ac.uk PlanetEarthWinter2002--www.nerc.ac.uk

    E-Print Network [OSTI]

    Newcastle upon Tyne, University of

    's main contractor, Subsea 7, runs ROVs around the clock. As part of a normal working day they may be left work class ROVs designed and operated by Subsea 7, called Centurion 21 and 30. There are also two

  6. Observation of giant exchange bias in bulk Mn{sub 50}Ni{sub 42}Sn{sub 8} Heusler alloy

    SciTech Connect (OSTI)

    Sharma, Jyoti; Suresh, K. G.

    2015-02-16

    We report a giant exchange bias (EB) field of 3520?Oe in bulk Mn{sub 50}Ni{sub 42}Sn{sub 8} Heusler alloy. The low temperature magnetic state of the martensite phase has been studied by DC magnetization and AC susceptibility measurements. Frequency dependence of spin freezing temperature (T{sub f}) on critical slowing down relation and observation of memory effect in zero field cooling mode confirms the super spin glass (SSG) phase at low temperatures. Large EB is attributed to the strong exchange coupling between the SSG clusters formed by small regions of ferromagnetic order embedded in an antiferromagnetic (AFM) matrix. The temperature and cooling field dependence of EB have been studied and related to the change in unidirectional anisotropy at SSG/AFM interface. The training effect also corroborates with the presence of frozen (SSG) moments at the interface and their role in EB.

  7. Bio-corrosion and cytotoxicity studies on novel Zr<sub>55sub>Co>30sub>Ti>15sub> and Cu<sub>60sub>Zr>20sub>Ti>20sub> metallic glasses

    SciTech Connect (OSTI)

    Vincent, S.; Daiwile, A.; Devi, S. S.; Kramer, M. J.; Besser, M. F.; Murty, B. S.; Bhatt, Jatin

    2014-09-26

    Metallic glasses are a potential and compatible implant candidate for biomedical applications. In the present investigation, a comparative study between novel Zr<sub>55sub>Co>30sub>Ti>15sub> and Cu<sub>60sub>Zr>20sub>Ti>20sub> metallic glasses is carried out to evaluate in vitro biocompatibility using simulated body fluids. The bio-corrosion behavior of Zr- and Cu-based metallic glasses in different types of artificial body fluids such as artificial saliva solution, phosphate-buffered saline solution, artificial blood plasma solution, and Hank’s balanced saline solution is evaluated using potentiodynamic polarization studies at a constant body temperature of 310.15 K (37 °C). Surface morphology of samples after bio-corrosion experiments was observed by scanning electron microscopy. In vitro cytotoxicity test on glassy alloys were performed using human osteosarcoma cell line as per 10993-5 guidelines from International Organization for Standardization. As a result, the comparative study between Zr- and Cu-based glassy alloys provides vital information about the effect of elemental composition on biocompatibility of metallic glasses.

  8. Optimizing white light luminescence in Dy{sup 3+}-doped Lu{sub 3}Ga{sub 5}O{sub 12} nano-garnets

    SciTech Connect (OSTI)

    Haritha, P.; Linganna, K.; Venkatramu, V.; Martín, I. R.; Monteseguro, V.; Rodríguez-Mendoza, U. R.; Babu, P.; León-Luis, S. F.; Jayasankar, C. K.; Lavín, V.

    2014-11-07

    Trivalent dysprosium-doped Lu{sub 3}Ga{sub 5}O{sub 12} nano-garnets have been prepared by sol-gel method and characterized by X-ray powder diffraction, high-resolution transmission electron microscopy, dynamic light scattering, and laser excited spectroscopy. Under a cw 457?nm laser excitation, the white luminescence properties of Lu{sub 3}Ga{sub 5}O{sub 12} nano-garnets have been studied as a function of the optically active Dy{sup 3+} ion concentration and at low temperature. Decay curves for the {sup 4}F{sub 9/2} level of Dy{sup 3+} ion exhibit non-exponential nature for all the Dy{sup 3+} concentrations, which have been well-fitted to a generalized energy transfer model for a quadrupole-quadrupole interaction between Dy{sup 3+} ions without diffusion. From these data, a simple rate-equations model can be applied to predict that intense white luminescence could be obtained from 1.8?mol% Dy{sup 3+} ions-doped nano-garnets, which is in good agreement with experimental results. Chromaticity color coordinates and correlated color temperatures have been determined as a function of temperature and are found to be within the white light region for all Dy{sup 3+} concentrations. These results indicate that 2.0?mol% Dy{sup 3+} ions doped nano-garnet could be useful for white light emitting device applications.

  9. Fundamental Understanding of Methane-Carbon Dioxide-Water (CH<sub>4sub>-CO>2sub>-H>2sub>O) Interactions in Shale Nanopores under Reservoir Conditions. Quarterly Report.

    SciTech Connect (OSTI)

    Wang, Yifeng

    2015-10-27

    This project focuses on the systematic study of CH<sub>4sub>-CO>2sub>-H>2sub>O interactions in shale nanopores under high-pressure and high temperature reservoir conditions. The proposed work will help to develop new stimulation strategies to enable efficient resource recovery from fewer and less environmentally impactful wells.

  10. Dimethyl sulfide substituted mixed-metal clusters: Synthesis, structure, and characterization of HRuCo sub 3 (CO) sub 11 (SMe sub 2 ) and (HRuRh sub 3 (CO) sub 9 ) sub 2 (SMe sub 2 ) sub 3

    SciTech Connect (OSTI)

    Rossi, S.; Pursianinen, J.; Ahlgren, M.; Pakkanen, T.A. (Univ. of Joensuu (Finland))

    1990-02-01

    Ligand substitution reactions of dimethyl sulfide with mixed-metal clusters are described. The clusters HRuCo{sub 3}(CO){sub 11}(SMe{sub 2}) (1) and (HRuRh{sub 3}(CO){sub 9}){sub 2}(SMe{sub 2}){sub 3} (2) have been prepared by reactions of SMe{sub 2} with the neutral parent clusters. Their crystal structures have been established: 1, monoclinic, space group P2{sub 1}/n, a = 11.459 (5) {angstrom}, b = 12.484 (4) {angstrom}, c = 14.384 (4) {angstrom}, {beta} = 96.40 (3){degree}, Z = 4; 2, trigonal, space group R3c, a = 13.181 (7) {angstrom}, {alpha} = 75.54 (5){degree}, Z = 2. Dimethyl sulfide coordinates terminally as a two-electron donor on basal cobalt in 1 and as a bridging four-electron donor causing unusual dimerization of clusters in 2. The carbonyl arrangement of the parent clusters was not changed during the ligand substitution, and hydride ligands bridge the three basal metals in both compounds.

  11. A Rh<sub>xSy>/C Catalyst for the Hydrogen Oxidation and Hydrogen Evolution Reactions in HBr

    SciTech Connect (OSTI)

    Masud, Jahangir; Nguyena, Trung V.; Singh, Nirala; McFarland, Eric; Ikenberry, Myles; Hohn, Keith; Pan, Chun-Jern; Hwang, Bing-Joe

    2015-01-01

    Rhodium sulfide (Rh<sub>2sub>S>3sub>) on carbon support was synthesized by refluxing rhodium chloride with ammonium thiosulfate. Thermal treatment of Rh<sub>2sub>S>3sub> at high temperatures (600°C to 850°C) in presence of argon resulted in the transformation of Rh<sub>2sub>S>3sub> into Rh<sub>3sub>S>4sub>, Rh<sub>17sub>S>15sub> and Rh which were characterized by TGA/DTA, XRD, EDX, and deconvolved XPS analyses. The catalyst particle size distribution ranged from 3 to 12 nm. Cyclic voltammetry and rotating disk electrode measurements were used to evaluate the catalytic activity for hydrogen oxidation and evolution reactions in H<sub>2sub>SO>4sub> and HBr solutions. The thermally treated catalysts show high activity for the hydrogen reactions. The exchange current densities (i<sub>o>) of the synthesized Rh<sub>xSy> catalysts in H<sub>2sub>-saturated 1M H<sub>2sub>SO>4sub> and 1M HBr for HER and HOR were 0.9 mA/cm2 to 1.0 mA/cm2 and 0.8 to 0.9 mA/cm2, respectively. The lower i<sub>o> values obtained in 1M HBr solution compared to in H<sub>2sub>SO>4sub> might be due to the adsorption of Br- on the active surface. Stable electrochemical active surface area (ECSA) of Rh<sub>xSy> catalyst was obtained for CV scan limits between 0 V and 0.65 V vs. RHE. Scans with upper voltage limit beyond 0.65 V led to decreased and unreproducible ECSA measurements.

  12. Graphitic carbon nitride/Cu{sub 2}O heterojunctions: Preparation, characterization, and enhanced photocatalytic activity under visible light

    SciTech Connect (OSTI)

    Tian, Yanlong; Chang, Binbin; Fu, Jie; Zhou, Baocheng; Liu, Jiyang; Xi, Fengna; Dong, Xiaoping, E-mail: xpdong@zstu.edu.cn

    2014-04-01

    As a metal-free semiconductor material, graphitic carbon nitride (C{sub 3}N{sub 4}), the high recombination rate of photogenerated charges and insufficient sunlight absorption limit its solar-based photocatalytic activity. Here, we reported the heterojunctions of C{sub 3}N{sub 4}–Cu{sub 2}O with a p–n junction structure, which was synthesized by a hydrothermal method. The HR-TEM result revealed an intimate interface between C{sub 3}N{sub 4} and Cu{sub 2}O in the heterojunction, and UV–vis diffuse reflection spectra showed their extended spectral response in the visible region compared with pure C{sub 3}N{sub 4}. These excellent structural and spectral properties, as well as p–n junction structures, endowed the C{sub 3}N{sub 4}–Cu{sub 2}O heterojunctions with enhanced photocatalytic activities. The possible photocatalytic mechanism that photogenerated holes as the mainly oxidant species in photocatalysis was proposed base on the trapping experiments. - Highlights: • A hydrothermal method was used to prepare C3N{sub 4}–Cu{sub 2}O heterojunction. • The resulting heterojunction possesses broader absorption in the visible region. • The material owns a high visible light activity and stability for dye degradation.

  13. Effect of annealing temperature on optical and electrical properties of ZrO{sub 2}?SnO{sub 2} based nanocomposite thin films

    SciTech Connect (OSTI)

    Anitha, V. S., E-mail: jolly2jolly@gmail.com; Lekshmy, S. Sujatha, E-mail: jolly2jolly@gmail.com; Berlin, I. John, E-mail: jolly2jolly@gmail.com; Joy, K., E-mail: jolly2jolly@gmail.com [Thin film Laboratory, Post Graduate and Research Department of Physics, Mar Ivanios College, Thiruvananthapuram 695 015 (India)

    2014-01-28

    Transparent nanocomposite ZrO{sub 2}?SnO{sub 2} thin films were prepared by sol-gel dip-coating technique. Films were annealed at 500°C, 800°C and 1200°C respectively. X-ray diffraction(XRD) spectra showed a mixture of three phases: tetragonal ZrO{sub 2} and SnO{sub 2} and orthorhombic ZrSnO{sub 4}. The grain size of all the three phases' increased with annealing temperature. An average transmittance greater than 85%(in UV-Visible region) is observed for all the films. The band gap for the films decreased from 4.79 eV to 4.62 eV with increase in annealing temperature from 500 to 1200 °C. The electrical resistivity increased with increase in annealing temperature. Such composite ZrO{sub 2}?SnO{sub 2} films can be used in many applications and in optoelectronic devices.

  14. RECALIBRATION OF THE VIRIAL FACTOR AND M{sub BH}-{sigma}{sub *} RELATION FOR LOCAL ACTIVE GALAXIES

    SciTech Connect (OSTI)

    Park, Daeseong; Woo, Jong-Hak [Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Kelly, Brandon C.; Treu, Tommaso, E-mail: pds2001@astro.snu.ac.kr, E-mail: woo@astro.snu.ac.kr, E-mail: bckelly@physics.ucsb.edu, E-mail: tt@physics.ucsb.edu [Department of Physics, University of California, Santa Barbara, CA 93106 (United States)

    2012-11-15

    Determining the virial factor of the broad-line region gas is crucial for calibrating active galactic nucleus black hole mass estimators, since the measured line-of-sight velocity needs to be converted into the intrinsic virial velocity. The average virial factor has been empirically calibrated based on the M{sub BH}-{sigma}{sub *} relation of quiescent galaxies, but the claimed values differ by a factor of two in recent studies. We investigate the origin of the difference by measuring the M{sub BH}-{sigma}{sub *} relation using an updated galaxy sample from the literature and explore the dependence of the virial factor on various fitting methods. We find that the discrepancy is primarily caused by the sample selection, while the difference stemming from the various regression methods is marginal. However, we generally prefer the FITEXY and Bayesian estimators based on Monte Carlo simulations for the M{sub BH}-{sigma}{sub *} relation. In addition, the choice of independent variable in the regression leads to {approx}0.2 dex variation in the virial factor inferred from the calibration process. Based on the determined virial factor, we present the updated M{sub BH}-{sigma}{sub *} relation of local active galaxies.

  15. Transfer between the cesium 6 {sup 2}P{sub 1/2} and 6 {sup 2}P{sub 3/2} levels induced by collisions with H{sub 2}, HD, D{sub 2}, CH{sub 4}, C{sub 2}H{sub 6}, CF{sub 4}, and C{sub 2}F{sub 6}

    SciTech Connect (OSTI)

    Pitz, Greg A.; Fox, Charles D.; Perram, Glen P.

    2011-09-15

    The cross sections of spin-orbit energy exchange between the cesium 6 {sup 2}P{sub 1/2}{r_reversible}6 {sup 2}P{sub 3/2} states induced by collisions with N{sub 2}, H{sub 2}, HD, D{sub 2}, CH{sub 4}, C{sub 2}H{sub 6}, CF{sub 4}, and C{sub 2}F{sub 6} were obtained for pressures less than 100 Torr at room temperature by means of steady-state laser-induced fluorescence techniques. The spin-orbit energy exchange rate with N{sub 2}, H{sub 2}, HD, D{sub 2}, CH{sub 4}, C{sub 2}H{sub 6}, CF{sub 4}, and C{sub 2}F{sub 6}, have been measured as {sigma}{sub 21}(6 {sup 2}P{sub 3/2}{yields}6 {sup 2}P{sub 1/2})= 16.3, 34.1, 30.0, 22.7, 21.4, 65.6, 64.8, and 137 A{sup 2} and {sigma}{sub 12}(6 {sup 2}P{sub 1/2}{yields}6 {sup 2}P{sub 3/2})= 1.8, 4.4, 4.1, 3.0, 2.9, 13.3, 9.7, and 16.3 A{sup 2}, respectively. Correlations of the spin-orbit transfer probabilities with rotational-energy defect and vibrational-energy defect have been shown.

  16. Synthesis and crystal structure of the palladium oxides NaPd{sub 3}O{sub 4}, Na{sub 2}PdO{sub 3} and K{sub 3}Pd{sub 2}O{sub 4}

    SciTech Connect (OSTI)

    Panin, Rodion V. [Department of Chemistry, Moscow State University, 119992, Moscow (Russian Federation)], E-mail: panin@icr.chem.msu.ru; Khasanova, Nellie R. [Department of Chemistry, Moscow State University, 119992, Moscow (Russian Federation); Abakumov, Artem M. [Department of Chemistry, Moscow State University, 119992, Moscow (Russian Federation); Antipov, Evgeny V. [Department of Chemistry, Moscow State University, 119992, Moscow (Russian Federation); Tendeloo, Gustaaf van [EMAT University of Antwerp (RUCA), Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Schnelle, Walter [Max-Planck Institute for Chemical Physics of Solids, Noethnitzer Street 40, 01187 Dresden (Germany)

    2007-05-15

    NaPd{sub 3}O{sub 4}, Na{sub 2}PdO{sub 3} and K{sub 3}Pd{sub 2}O{sub 4} have been prepared by solid-state reaction of Na{sub 2}O{sub 2} or KO{sub 2} and PdO in sealed silica tubes. Crystal structures of the synthesized phases were refined by the Rietveld method from X-ray powder diffraction data. NaPd{sub 3}O{sub 4} (space group Pm3-barn, a=5.64979(6) A, Z=2) is isostructural to NaPt{sub 3}O{sub 4}. It consists of NaO{sub 8} cubes and PdO{sub 4} squares, corner linked into a three-dimensional framework where the planes of neighboring PdO{sub 4} squares are perpendicular to each other. Na{sub 2}PdO{sub 3} (space group C2/c, a=5.3857(1) A, b=9.3297(1) A, c=10.8136(2) A, {beta}=99.437(2){sup o}, Z=8) belongs to the Li{sub 2}RuO{sub 3}-structure type, being the layered variant of the NaCl structure, where the layers of octahedral interstices filled with Na{sup +} and Pd{sup 4+} cations alternate with Na{sub 3} layers along the c-axis. Na{sub 2}PdO{sub 3} exhibits a stacking disorder, detected by electron diffraction and Rietveld refinement. K{sub 3}Pd{sub 2}O{sub 4}, prepared for the first time, crystallizes in the orthorhombic space group Cmcm (a=6.1751(6) A, b=9.1772(12) A, c=11.3402(12) A, Z=4). Its structure is composed of planar PdO{sub 4} units connected via common edges to form parallel staggered PdO{sub 2} strips, where potassium atoms are located between them. Magnetic susceptibility measurements of K{sub 3}Pd{sub 2}O{sub 4} reveal a Curie-Weiss behavior in the temperature range above 80 K. - Graphical abstract: Na{sub 2}PdO{sub 3} (space group C2/c, a=5.3857(1) A, b=9.3297(1) A, c=10.8136(2) A, {beta}=99.437(2), Z=8) belongs to the Li{sub 2}RuO{sub 3}-structure type, being the layered variant of the NaCl structure, where the layers of octahedral interstices filled with Na{sup +} and Pd{sup 4+} cations (NaPd{sub 2}O{sub 6} slabs) alternate with Na{sub 3} layers along the c-axis.

  17. Nanocrystallization in spark plasma sintered Fe{sub 48}Cr{sub 15}Mo{sub 14}Y{sub 2}C{sub 15}B{sub 6} bulk amorphous alloy

    SciTech Connect (OSTI)

    Singh, Ashish; Harimkar, Sandip P.; Katakam, Shravana; Dahotre, Narendra B.; Ilavsky, Jan

    2013-08-07

    Spark plasma sintering (SPS) is evolving as an attractive process for the processing of multi-component Fe-based bulk amorphous alloys and their in-situ nanocomposites with controlled primary nanocrystallization. Extended Q-range small angle neutron scattering (EQ-SANS) analysis, complemented by x-ray diffraction and transmission electron microscopy, was performed to characterize nanocrystallization behavior of SPS sintered Fe-based bulk amorphous alloys. The SANS experiments show significant scattering for the samples sintered in the supercooled region indicating local structural/compositional changes associated with the profuse nucleation of nanoclusters (?4 nm). For the samples spark plasma sintered near and above crystallization temperature (>653 °C), the SANS data show the formation of interference maximum indicating the formation and growth of (Fe,Cr){sub 23}C{sub 6} crystallites. The SANS data also indicate the evolution of bimodal crystallite distribution at higher sintering temperatures (above T{sub x1}). The growth of primary nanocrystallites results in impingement of concentration gradient fields (soft impingement effect), leading to non-random nucleation of crystallites near the primary crystallization.

  18. Facile synthesis of Ba<sub>1-xsub>Kx>Fe?As? superconductors via hydride route

    SciTech Connect (OSTI)

    Zaikina, Julia V. [Univ. of California at Davis, Davis, CA (United States); Batuk, Maria [Univ. of Antwerp, Antwerp (Belgium); Abakumov, Artem M. [Univ. of Antwerp, Antwerp (Belgium); Navrotsky, Alexandra [Univ. of California at Davis, Davis, CA (United States); Kauzlarich, Susan M. [Univ. of California at Davis, Davis, CA (United States)

    2014-12-03

    We have developed a fast, easy, and scalable synthesis method for Ba<sub>1-xsub>Kx>Fe?As? (0 ? x ? 1) superconductors using hydrides BaH? and KH as a source of barium and potassium metals. Synthesis from hydrides provides better mixing and easier handling of the starting materials, consequently leading to faster reactions and/or lower synthesis temperatures. The reducing atmosphere provided by the evolved hydrogen facilitates preparation of oxygen-free powders. By a combination of methods we have shown that Ba<sub>1-xsub>Kx>Fe?As? obtained via hydride route has the same characteristics as when it is prepared by traditional solid-state synthesis. Refinement from synchrotron powder X-ray diffraction data confirms a linear dependence of unit cell parameters upon K content as well as the tetragonal to orthorhombic transition at low temperatures for compositions with x < 0.2. Magnetic measurements revealed dome-like dependence of superconducting transition temperature T<sub>c> upon K content with a maximum of 38 K for x close to 0.4. Electron diffraction and high-resolution high-angle annular dark-field scanning transmission electron microscopy indicates an absence of Ba/K ordering, while local inhomogeneity in the Ba/K distribution takes place at a scale of several angstroms along [110] crystallographic direction.

  19. Magnetic domain structure and domain-wall energy in UFe{sub 8}Ni{sub 2}Si{sub 2} and UFe{sub 6}Ni{sub 4}Si{sub 2} intermetallic compounds

    SciTech Connect (OSTI)

    Wyslocki, J.J.; Suski, W.; Wochowski, K.

    1994-03-01

    Magnetic domain structures in the UFe{sub 8}Ni{sub 2}Si{sub 2} and UFe{sub 6}Ni{sub 4}Si{sub 2} compounds were studied using the powder pattern method. The domain structure observed is typical for uniaxial materials. The domain-wall energy density {gamma} was determined from the average surface domain width D{sub s} observed on surfaces perpendicular to the easy axis as equal to 16 erg/cm{sup 2} for UFe{sub 8}Ni{sub 2}Si{sub 2} and 10 erg/cm{sup 2} for UFe{sub 6}Ni{sub 4}Si{sub 2}. Moreover, the critical diameter for single domain particle D{sub c} was calculated for the studied compounds.

  20. Crystal structure and physical properties of quaternary clathrates Ba{sub 8}Zn{sub x}Ge{sub 46-x-y}Si{sub y}, Ba{sub 8}(Zn,Cu){sub x}Ge{sub 46-x} and Ba{sub 8}(Zn,Pd){sub x}Ge{sub 46-x}

    SciTech Connect (OSTI)

    Nasir, Navida; Grytsiv, Andriy; Melnychenko-Koblyuk, Nataliya [Institute of Physical Chemistry, University of Vienna, A-1090 Wien (Austria); Rogl, Peter, E-mail: peter.franz.rogl@univie.ac.a [Institute of Physical Chemistry, University of Vienna, A-1090 Wien (Austria); Bednar, Ingeborg; Bauer, Ernst [Institute of Solid State Physics, Vienna University of Technology, A-1040 Wien (Austria)

    2010-10-15

    Three series of vacancy-free quaternary clathrates of type I, Ba{sub 8}Zn{sub x}Ge{sub 46-x-y}Si{sub y}, Ba{sub 8}(Zn,Cu){sub x}Ge{sub 46-x}, and Ba{sub 8}(Zn,Pd){sub x}Ge{sub 46-x}, have been prepared by reactions of elemental ingots in vacuum sealed quartz at 800 {sup o}C. In all cases cubic primitive symmetry (space group Pm3n, a{approx}1.1 nm) was confirmed for the clathrate phase by X-ray powder diffraction and X-ray single crystal analyses. The lattice parameters show a linear increase with increase in Ge for Ba{sub 8}Zn{sub x}Ge{sub 46-x-y}Si{sub y}. M atoms (Zn, Pd, Cu) preferably occupy the 6d site in random mixtures. No defects were observed for the 6d site. Site preference of Ge and Si in Ba{sub 8}Zn{sub x}Ge{sub 46-x-y}Si{sub y} has been elucidated from X-ray refinement: Ge atoms linearly substitute Si in the 24k site whilst a significant deviation from linearity is observed for occupation of the 16i site. A connectivity scheme for the phase equilibria in the 'Ba{sub 8}Ge{sub 46}' corner at 800 {sup o}C has been derived and a three-dimensional isothermal section at 800 {sup o}C is presented for the Ba-Pd-Zn-Ge system. Studies of transport properties carried out for Ba{sub 8{l_brace}}Cu,Pd,Zn{r_brace}{sub x}Ge{sub 46-x} and Ba{sub 8}Zn{sub x}Si{sub y}Ge{sub 46-x-y} evidenced predominantly electrons as charge carriers and the closeness of the systems to a metal-to-insulator transition, fine-tuned by substitution and mechanical processing of starting material Ba{sub 8}Ge{sub 43}. A promising figure of merit, ZT {approx}0.45 at 750 K, has been derived for Ba{sub 8}Zn{sub 7.4}Ge{sub 19.8}Si{sub 18.8}, where pricey germanium is exchanged by reasonably cheap silicon. - Graphical abstract: Quaternary phase diagram of Ba-Pd-Zn-Ge system at 800 {sup o}C.

  1. Controlling superconductivity in La<sub>2-xsub>SrxCuO>4+?sub> by ozone and vacuum annealing

    SciTech Connect (OSTI)

    Leng, Xiang; Bozovic, Ivan

    2014-11-21

    In this study we performed a series of ozone and vacuum annealing experiments on epitaxial La<sub>2-xsub>SrxCuO>4+?sub> thin films. The transition temperature after each annealing step has been measured by the mutual inductance technique. The relationship between the effective doping and the vacuum annealing time has been studied. Short-time ozone annealing at 470 °C oxidizes an underdoped film all the way to the overdoped regime. The subsequent vacuum annealing at 350 °C to 380 °C slowly brings the sample across the optimal doping point back to the undoped, non-superconducting state. Several ozone and vacuum annealing cycles have been done on the same sample and the effects were found to be repeatable and reversible Vacuum annealing of ozone-loaded LSCO films is a very controllable process, allowing one to tune the doping level of LSCO in small steps across the superconducting dome, which can be used for fundamental physics studies.

  2. Sub-micron filter

    DOE Patents [OSTI]

    Tepper, Frederick (Sanford, FL); Kaledin, Leonid (Port Orange, FL)

    2009-10-13

    Aluminum hydroxide fibers approximately 2 nanometers in diameter and with surface areas ranging from 200 to 650 m.sup.2/g have been found to be highly electropositive. When dispersed in water they are able to attach to and retain electronegative particles. When combined into a composite filter with other fibers or particles they can filter bacteria and nano size particulates such as viruses and colloidal particles at high flux through the filter. Such filters can be used for purification and sterilization of water, biological, medical and pharmaceutical fluids, and as a collector/concentrator for detection and assay of microbes and viruses. The alumina fibers are also capable of filtering sub-micron inorganic and metallic particles to produce ultra pure water. The fibers are suitable as a substrate for growth of cells. Macromolecules such as proteins may be separated from each other based on their electronegative charges.

  3. Structure and optical properties of a noncentrosymmetric borate RbSr{sub 4}(BO{sub 3}){sub 3}

    SciTech Connect (OSTI)

    Xia, M.J.; Li, R.K.

    2013-01-15

    A new noncentrosymmetric borate, RbSr{sub 4}(BO{sub 3}){sub 3} (abbreviated as RSBO), has been grown from Rb{sub 2}O--B{sub 2}O{sub 3}--RbF flux and its crystal structure was determined by single crystal x-ray diffraction. It crystallizes in space group Ama2 with cell parameters of a=11.128(10) A, b=12.155(15) A, c=6.952(7) A, Z=4. The basic structural units are isolated planar BO{sub 3} groups. Second harmonic generation (SHG) test of the title compound by the Kurtz-Perry method shows that RSBO can be phase matchable with an effective SHG coefficient about two-thirds as large as that of KH{sub 2}PO{sub 4} (KDP). Finally, based on the anionic group approximation, the optical properties of the title compound are compared with those of the structure-related apatite-like compounds with the formula 'A{sub 5}(TO{sub n}){sub 3}X'. - Graphical abstract: RbSr{sub 4}(BO{sub 3}){sub 3} and some other borate NLO compounds, namely Ca{sub 5}(BO{sub 3}){sub 3}F RCa{sub 4}(BO{sub 3}){sub 3}O (R=Y or Gd) and Na{sub 3}La{sub 2}(BO{sub 3}){sub 3} can be viewed as the derivatives of apatite. They have similar formula composed of five cations and three anion groups (we call them 5/3 structures). The detailed SHG coefficients and optical properties of the apatite-like NLO crystals were compared and summarized. Highlights: Black-Right-Pointing-Pointer A new noncentrosymmetric borate RbSr{sub 4}(BO{sub 3}){sub 3} was grown from flux. Black-Right-Pointing-Pointer The RbSr{sub 4}(BO{sub 3}){sub 3} can be viewed as a derivative of the apatite-like structure. Black-Right-Pointing-Pointer The structure and its relationship to the optical properties of RbSr{sub 4}(BO{sub 3}){sub 3} are compared with other NLO crystals with apatite-like structures. Black-Right-Pointing-Pointer The basic structural units are the planar BO{sub 3} groups in the structure. Black-Right-Pointing-Pointer Second harmonic generation (SHG) test shows that RbSr{sub 4}(BO{sub 3}){sub 3} can be phase matchable with an effective SHG coefficient about two-thirds as large as that of KH{sub 2}PO{sub 4}.

  4. Laser Induced Molecular Spectroscopy of Zn{sub 2} Molecule

    SciTech Connect (OSTI)

    Singh, Subhash C.; Gopal, Ram [Laser Spectroscopy and Nanomaterials Lab, Department of Physics, University of Allahabad, Allahabad-211002 (India)

    2008-11-14

    Laser produced spectra of zinc molecule have been recorded in the region of 540-670 nm using second harmonics of Nd: YAG laser, computer--controlled TRIAX 320 M monochromator with a reciprocal linear dispersion 2.64 nm/mm fitted with ICCD detector. The spectrum consists of 35 bands, which are classified into D ({sup 1} product {sub u}){yields}A({sup 3} product {sub g}) and C ({sup 1}{sigma}{sub u}{sup +}){yields}A({sup 3} product {sub g}) systems. We have recorded the florescence spectrum of zinc dimer by pumping and probing with the same laser, which proves that produced molecules are stable for more than 0.1 seconds.

  5. Ordered structures in YBa/sub 2/Cu/sub 3/O/sub 7-y/, La/sub 2-x/Sr/sub x/CuO/sub 4-par. delta/ and related perovskites

    SciTech Connect (OSTI)

    Mitchell, T.E.; Roy, T.; Fisk, Z.; Smith, J.L.

    1988-01-01

    Electron microscopy and electron diffraction studies have been performed on the superconducting oxides YBa/sub 2/Cu/sub 3/O/sub 7-y/, GdBa/sub 2/Cu/sub 3/O/sub 7-y/ and La/sub 2-x/Sr/sub x/CuO/sub 4-par. delta/ as well as the related perovskites La/sub 2/CuO/sub 4/, Eu/sub 2/CuO/sub 4/ and Gd/sub 2/CuO/sub 4/. Extra reflections are commonly observed in all the cases. For example, in the 123 compounds, in situ heating leads to transformations from orthorhombic to tetragonal with a loss of twin structure; on cooling the oxygen vacancies re-order in the basal plane to give 1/3(100)* or 1/4(110)* diffraction spots. In tetragonal Eu/sub 2/CuO/sub 4/ and Gd/sub 2/CuO/sub 4/, the (001) diffraction patterns often have extra spots at 1/2(110)* or at 1/4(110)* positions. Extra spots are also observed in La/sub 2/CuO/sub 4/ (orthorhombic) but this is probably due to the space group being primitive rather than centered. These observations are discussed in terms of the ordering of oxygen vacancies in the Cu-O planes of the various perovskite structures. 6 figs.

  6. Josephson junctions in high-T/sub c/ superconductors

    DOE Patents [OSTI]

    Falco, C.M.; Lee, T.W.

    1981-01-14

    The invention includes a high T/sub c/ Josephson sperconducting junction as well as the method and apparatus which provides the junction by application of a closely controlled and monitored electrical discharge to a microbridge region connecting two portions of a superconducting film.

  7. Characteristics of atmospheric-pressure non-thermal N{sub 2} and N{sub 2}/O{sub 2} gas mixture plasma jet

    SciTech Connect (OSTI)

    Xiao, Dezhi; Shen, Jie; Lan, Yan; Xie, Hongbing; Shu, Xingsheng; Meng, Yuedong; Li, Jiangang; Cheng, Cheng E-mail: paul.chu@cityu.edu.hk; Chu, Paul K. E-mail: paul.chu@cityu.edu.hk

    2014-01-21

    An atmospheric-pressure non-thermal plasma jet driven by high frequency alternating current and operating on N{sub 2} and N{sub 2}/O{sub 2} gas mixture is investigated. The plasma jet can reach 55?mm in length at a gas flow rate of 2500?l/h. The gas temperature at a distance of 4?mm from the nozzle is close to room temperature. Optical emission spectroscopy is employed to investigate the important plasma parameters such as the excited species, rotational temperature, vibrational temperature, and excitation temperature under different discharge conditions. The results show that the plasma source operates under non-equilibrium conditions. The absolute irradiance intensity of the vibrational band N{sub 2}(C-B) in the active region is measured. Taking into account the irradiance intensity of N{sub 2}(C-B,0-0) and N{sub 2}(B-X,0-0) as well as measured current, the electron density, which is determined by considering direct and step-wise electron impact excitation of nitrogen emission, reaches a maximum value of 5.6?×?10{sup 20}/m{sup 3}.

  8. Electronic and optical properties of layered RE{sub 2}Ti{sub 2}O{sub 7} (RE = Ce and Pr) from first principles

    SciTech Connect (OSTI)

    Sayede, A.; Khenata, R.; Chahed, A.; Benhelal, O.

    2013-05-07

    We have studied the structural and electronic properties of Ce{sub 2}Ti{sub 2}O{sub 7} (CeTO) and Pr{sub 2}Ti{sub 2}O{sub 7} (PrTO) by first-principles density functional theory calculations. The computed structural parameters are in fairly good agreement with the available experimental findings. Band structure calculations using the GGA+U approach predict an insulating ground state for the herein studied compounds. The insulating band gaps of 2.00 eV and 2.83 eV are found for CeTO and PrTO, respectively. The analysis of the density of states reveals that the strongly localized RE 4f levels act as charge-trapping sites, predicting a lower photocatalytic activity for CeTO. We have also calculated the optical properties for both CeTO and PrTO. Based on these properties, it is predicted that these titanates are insensitive to ultra-violet radiation, while they are more sensitive to frequencies of the radiation in visible and early UV regions.

  9. Crystallographic, electronic, thermal, and magnetic properties of single-crystal SrCo<sub>2sub>As>2sub>

    SciTech Connect (OSTI)

    Pandey, Abhishek; Quirinale, D. G.; Jayasekara, W.; Sapkota, A.; Kim, M. G.; Dhaka, R. S.; Lee, Y.; Heitmann, T. W.; Stephens, P. W.; Ogloblichev, V.; Kreyssig, A.; McQueeney, R. J.; Goldman, A. I.; Kaminski, Adam; Harmon, B. N.; Furukawa, Y.; Johnston, D. C.

    2013-07-01

    In tetragonal SrCo<sub>2sub>As>2 sub>single crystals, inelastic neutron scattering measurements demonstrated that strong stripe-type antiferromagnetic (AFM) correlations occur at a temperature T = 5 K [W. Jayasekara et al., arXiv:1306.5174] that are the same as in the isostructural AFe<sub>2sub>As>2sub> (A = Ca, Sr, Ba) parent compounds of high-T<sub>c> superconductors. This surprising discovery suggests that SrCo<sub>2sub>As>2sub> may also be a good parent compound for high-T<sub>c sub>superconductivity. Here, structural and thermal expansion, electrical resistivity ?, angle-resolved photoemission spectroscopy (ARPES), heat capacity C<sub>p>, magnetic susceptibility ?, 75As NMR and neutron diffraction measurements of SrCo<sub>2sub>As>2sub> crystals are reported together with LDA band structure calculations that shed further light on this fascinating material. The c-axis thermal expansion coefficient ?<sub>c> is negative from 7 to 300 K, whereas ?<sub>a> is positive over this T range. The ?(T) shows metallic character. The ARPES measurements and band theory confirm the metallic character and in addition show the presence of a flat band near the Fermi energy E<sub>F>. The band calculations exhibit an extremely sharp peak in the density of states D(E<sub>F>) arising from a flat d<sub>x2-y2sub> band. A comparison of the Sommerfeld coefficient of the electronic specific heat with ?(T ? 0) suggests the presence of strong ferromagnetic itinerant spin correlations which on the basis of the Stoner criterion predicts that SrCo<sub>2sub>As>2sub> should be an itinerant ferromagnet, in conflict with the magnetization data. The ?(T) does have a large magnitude, but also exhibits a broad maximum at 115 K suggestive of dynamic short-range AFM spin correlations, in agreement with the neutron scattering data. The measurements show no evidence for any type of phase transition between 1.3 and 300 K and we propose that metallic SrCo<sub>2sub>As>2sub> has a gapless quantum spin-liquid ground state.

  10. Measurement of the ?<sub>b>? lifetime in the exclusive decay ?<sub>b>??J/??? in pp? collisions at ?s=1.96 TeV

    SciTech Connect (OSTI)

    Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Alverson, G.; Aoki, M.; Askew, A.; Atkins, S.; Augsten, K.; Avila, C.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Barberis, E.; Baringer, P.; Barreto, J.; Bartlett, J. F.; Bassler, U.; Bazterra, V.; Bean, A.; Begalli, M.; Bellantoni, L.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besançon, M.; Beuselinck, R.; Bezzubov, V. A.; Bhat, P. C.; Bhatia, S.; Bhatnagar, V.; Blazey, G.; Blessing, S.; Bloom, K.; Boehnlein, A.; Boline, D.; Boos, E. E.; Borissov, G.; Bose, T.; Brandt, A.; Brandt, O.; Brock, R.; Brooijmans, G.; Bross, A.; Brown, D.; Brown, J.; Bu, X. B.; Buehler, M.; Buescher, V.; Bunichev, V.; Burdin, S.; Buszello, C. P.; Camacho-Pérez, E.; Casey, B. C. K.; Castilla-Valdez, H.; Caughron, S.; Chakrabarti, S.; Chakraborty, D.; Chan, K. M.; Chandra, A.; Chapon, E.; Chen, G.; Chevalier-Théry, S.; Cho, D. K.; Cho, S. W.; Choi, S.; Choudhary, B.; Cihangir, S.; Claes, D.; Clutter, J.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M.-C.; Croc, A.; Cutts, D.; Das, A.; Davies, G.; de Jong, S. J.; De La Cruz-Burelo, E.; Déliot, F.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; Deterre, C.; DeVaughan, K.; Diehl, H. T.; Diesburg, M.; Ding, P. F.; Dominguez, A.; Dubey, A.; Dudko, L. V.; Duggan, D.; Duperrin, A.; Dutt, S.; Dyshkant, A.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Enari, Y.; Evans, H.; Evdokimov, A.; Evdokimov, V. N.; Facini, G.; Feng, L.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Fortner, M.; Fox, H.; Fuess, S.; Garcia-Bellido, A.; García-González, J. A.; García-Guerra, G. A.; Gavrilov, V.; Gay, P.; Geng, W.; Gerbaudo, D.; Gerber, C. E.; Gershtein, Y.; Ginther, G.; Golovanov, G.; Goussiou, A.; Grannis, P. D.; Greder, S.; Greenlee, H.; Grenier, G.; Gris, Ph.; Grivaz, J.-F.; Grohsjean, A.; Grünendahl, S.; Grünewald, M. W.; Guillemin, T.; Gutierrez, G.; Gutierrez, P.; Haas, A.; Hagopian, S.; Haley, J.; Han, L.; Harder, K.; Harel, A.; Hauptman, J. M.; Hays, J.; Head, T.; Hebbeker, T.; Hedin, D.; Hegab, H.; Heinson, A. P.; Heintz, U.; Hensel, C.; Heredia-De La Cruz, I.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hoang, T.; Hobbs, J. D.; Hoeneisen, B.; Hohlfeld, M.; Howley, I.; Hubacek, Z.; Hynek, V.; Iashvili, I.; Ilchenko, Y.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffré, M.; Jayasinghe, A.; Jesik, R.; Johns, K.; Johnson, E.; Johnson, M.; Jonckheere, A.; Jonsson, P.; Joshi, J.; Jung, A. W.; Juste, A.; Kaadze, K.; Kajfasz, E.; Karmanov, D.; Kasper, P. A.; Katsanos, I.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. N.; Kiselevich, I.; Kohli, J. M.; Kozelov, A. V.; Kraus, J.; Kulikov, S.; Kumar, A.; Kupco, A.; Kur?a, T.; Kuzmin, V. A.; Lammers, S.; Landsberg, G.; Lebrun, P.; Lee, H. S.; Lee, S. W.; Lee, W. M.; Lellouch, J.; Li, H.; Li, L.; Li, Q. Z.; Lim, J. K.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, H.; Liu, Y.; Lobodenko, A.; Lokajicek, M.; Lopes de Sa, R.; Lubatti, H. J.; Luna-Garcia, R.; Lyon, A. L.; Maciel, A. K. A.; Madar, R.; Magaña-Villalba, R.; Malik, S.; Malyshev, V. L.; Maravin, Y.; Martínez-Ortega, J.; McCarthy, R.; McGivern, C. L.; Meijer, M. M.; Melnitchouk, A.; Menezes, D.; Mercadante, P. G.; Merkin, M.; Meyer, A.; Meyer, J.; Miconi, F.; Mondal, N. K.; Mulhearn, M.; Nagy, E.; Naimuddin, M.; Narain, M.; Nayyar, R.; Neal, H. A.; Negret, J. P.; Neustroev, P.; Nunnemann, T.; Obrant, G.; Orduna, J.; Osman, N.; Osta, J.; Padilla, M.; Pal, A.; Parashar, N.; Parihar, V.; Park, S. K.; Partridge, R.; Parua, N.; Patwa, A.; Penning, B.; Perfilov, M.; Peters, Y.; Petridis, K.; Petrillo, G.; Pétroff, P.; Pleier, M.-A.; Podesta-Lerma, P. L. M.; Podstavkov, V. M.; Popov, A. V.; Prewitt, M.; Price, D.; Prokopenko, N.; Qian, J.; Quadt, A.; Quinn, B.; Rangel, M. S.; Ranjan, K.; Ratoff, P. N.; Razumov, I.; Renkel, P.; Ripp-Baudot, I.; Rizatdinova, F.; Rominsky, M.; Ross, A.; Royon, C.; Rubinov, P.; Ruchti, R.; Sajot, G.; Salcido, P.; Sánchez-Hernández, A.; Sanders, M. P.; Sanghi, B.; Santos, A. S.; Savage, G.; Sawyer, L.; Scanlon, T.; Schamberger, R. D.; Scheglov, Y.; Schellman, H.; Schlobohm, S.; Schwanenberger, C.; Schwienhorst, R.; Sekaric, J.; Severini, H.; Shabalina, E.; Shary, V.; Shaw, S.; Shchukin, A. A.; Shivpuri, R. K.; Simak, V.; Skubic, P.; Slattery, P.; Smirnov, D.; Smith, K. J.; Snow, G. R.; Snow, J.; Snyder, S.; Söldner-Rembold, S.; Sonnenschein, L.; Soustruznik, K.; Stark, J.; Stoyanova, D. A.; Strauss, M.; Stutte, L.; Suter, L.; Svoisky, P.; Takahashi, M.; Titov, M.; Tokmenin, V. V.; Tsai, Y.-T.; Tschann-Grimm, K.; Tsybychev, D.; Tuchming, B.; Tully, C.; Uvarov, L.; Uvarov, S.; Uzunyan, S.; Van Kooten, R.

    2012-06-01

    We measure the ??<sub>b> lifetime in the fully reconstructed decay ??<sub>b>?J/??? using 10.4 fb?¹ of pp? collisions collected with the D0 detector at ?s=1.96 TeV. The lifetime of the topologically similar decay channel B??J/?K?<sub>S> is also measured. We obtain ?(??<sub>b>)=1.303±0.075(stat)±0.035(syst) ps and ?(B?)=1.508±0.025(stat)±0.043(syst) ps. Using these measurements, we determine the lifetime ratio of ?(??<sub>b>)/?(B?)=0.864±0.052(stat)±0.033(syst).

  11. In Situ Foaming of Porous (La <sub>0.6sub> Sr <sub>0.4sub> ) <sub>0.98sub> (Co <sub>0.2sub> Fe <sub>0.8sub> ) O <sub>3??sub> (LSCF) Cathodes for Solid Oxide Fuel Cell Applications

    SciTech Connect (OSTI)

    Gandavarapu, Sodith; Sabolsky, Edward; Sabolsky, Katarzyna; Gerdes, Kirk

    2015-01-01

    A binder system containing polyurethane precursors was used to in situ foam (direct foam) a (La{sub 0.6}Sr{sub 0.4}){sub 0.98} (Co{sub 0.2} Fe{sub 0.8}) O{sub 3-{#2;delta}} (LSCF) composition for solid oxide fuel cell (SOFC) cathode applications. The relation between in situ foaming parameters on the final microstructure and electrochemical properties was characterized by microscopy and electrochemical impedance spectroscopy (EIS), respectively. The optimal porous cathode architecture was formed with a 70 vol% solids loading within a polymer precursor composition with a volume ratio of 8:4:1 (isocyanate: PEG: surfactant) in a terpineol-based ink vehicle. The resultant microstructure displayed a broad pore size distribution with highly elongated pore structure.

  12. Correlation between upconversion photoluminescence and dielectric response in Ba-substituted (Sr{sub 1?x}Ba{sub x}){sub 4}(La{sub 0.85}Ho{sub 0.025}Yb{sub 0.125}){sub 2}Ti{sub 4}Nb{sub 6}O{sub 30}

    SciTech Connect (OSTI)

    Wei, T., E-mail: weitong.nju@gmail.com [College of Science, Civil Aviation University of China, Tianjin 300300 (China); Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093 (China); Wang, X. D. [College of Science, Civil Aviation University of China, Tianjin 300300 (China); Zhao, C. Z. [School of Electronics and Information Engineering, Tianjin Polytechnic University, Tianjin 300160 (China); Liu, M. F.; Liu, J. M., E-mail: liujm@nju.edu.cn [Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093 (China)

    2014-06-30

    The filled tetragonal tungsten bronze (Sr{sub 1?x}Ba{sub x}){sub 4}(La{sub 0.85}Ho{sub 0.025}Yb{sub 0.125}){sub 2}Ti{sub 4}Nb{sub 6}O{sub 30} (SBLTNx: Ho-Yb) ceramics with different Ba substitution levels (x) are prepared. The upconversion photoluminescence (UC-PL) and dielectric permittivity are investigated. The substitution of Sr{sup 2+} ions at the A{sub 2}-sites by larger Ba{sup 2+} ions results in substantial variation of the UC-PL intensity as a function of substitution level x. Furthermore, the dielectric response to the substitution of Sr{sup 2+} by Ba{sup 2+} suggests a close correlation between the UC-PL intensity and dielectric permittivity. The origin for this correlation is discussed based on the random stress field (RSF) model.

  13. Combined SO sub 2 /NO sub x reduction technology

    SciTech Connect (OSTI)

    Livengood, C.D.; Huang, H.S. (Argonne National Lab., IL (United States)); Markussen, J.M. (USDOE Pittsburgh Energy Technology Center, PA (United States))

    1992-01-01

    Enactment of the Clean Air Act Amendments and passage of state legislation leading to more stringent nitrogen oxides (NO{sub x}) regulations have fueled research and development efforts on technologies for the combined control of sulfur dioxide (SO{sub 2}) and NO{sub x}. The integrated removal of both SO{sub 2} and NO{sub x}, in a single system can offer significant advantages over the use of several separate processes, including such factors as reduced system complexity, better operability, and lower costs. This paper reviews the status of a number of integrated flue-gas-cleanup (FGC) systems that have reached a significant stage of development, focusing on post-combustion processes that have been tested or are ready for testing at the pilot scale or larger. A brief process description, a summary of the development status and performance achieved to date, pending commercialization issues, and process economics (when available) are given for each technology.

  14. Method for making graded I-III-VI.sub.2 semiconductors and solar cell obtained thereby

    DOE Patents [OSTI]

    Devaney, Walter E. (Seattle, WA)

    1987-08-04

    Improved cell photovoltaic conversion efficiencies are obtained by the simultaneous elemental reactive evaporation process of Mickelsen and Chen for making semiconductors by closer control of the evaporation rates and substrate temperature during formation of the near contact, bulk, and near junction regions of a graded I-III-VI.sub.2, thin film, semiconductor, such as CuInSe.sub.2 /(Zn,Cd)S or another I-III-VI.sub.2 /II-VI heterojunction.

  15. Li{sub 2}B{sub 3}O{sub 4}F{sub 3}, a new lithium-rich fluorooxoborate

    SciTech Connect (OSTI)

    Pilz, Thomas; Nuss, Hanne; Jansen, Martin

    2012-02-15

    The new lithium fluorooxoborate, Li{sub 2}B{sub 3}O{sub 4}F{sub 3}, is obtained by a solid state reaction from LiBO{sub 2} and LiBF{sub 4} at 553 K and crystallizes in the acentric orthorhombic space group P2{sub 1}2{sub 1}2{sub 1} (no. 19) with the cell parameters a=4.8915(9), b=8.734(2), and c=12.301(2) A. Chains of fluorinated boroxine rings along the b axis consists of BO{sub 3} triangles and BO{sub 2}F{sub 2} as well as BO{sub 3}F tetrahedra. Mobile lithium ions are compensating the negative charge of the anionic chain, in which the fourfold coordinated boron atoms bear a negative formal charge. Annealing Li{sub 2}B{sub 3}O{sub 4}F{sub 3} at temperatures above 573 K leads to conversion into Li{sub 2}B{sub 6}O{sub 9}F{sub 2}. The title compound is an ionic conductor with the highest ion conductivity among the hitherto know lithium fluorooxoborates, with conductivities of 1.6 Multiplication-Sign 10{sup -9} and 1.8 Multiplication-Sign 10{sup -8} S cm{sup -1} at 473 and 523 K, respectively. - Graphical abstract: Repetition unit of Li{sub 2}B{sub 3}O{sub 4}F{sub 3}. Highlights: Black-Right-Pointing-Pointer Li{sub 2}B{sub 3}O{sub 4}F{sub 3} is the third member within the family of lithium fluorooxoborates. Black-Right-Pointing-Pointer It shows the highest lithium ion conductivity among them. Black-Right-Pointing-Pointer Chains of interconnected fluorinated boroxine rings run along the b axis. Black-Right-Pointing-Pointer Acentric space group meets the requirement for second harmonic generation.

  16. Magnetic measurements on ??CS{sub 2}U{sub 4}O{sub 12}

    SciTech Connect (OSTI)

    Kanrar, Buddhadev Misra, N. L.; Sastry, P. U.; Dube, V.; Ravikumar, G.

    2014-04-24

    Magnetic and XRD measurements on ??CS{sub 2}U{sub 4}O{sub 12} having uranium in mixed valent states of U (V) and U (VI) have been made. The study reveals that the compound undergoes an antiferromagnetic transition below 25K and an anomalous magnetic behavior was seen around 75K. This anomalous behavior indicates towards a structural phase transition. However, the low temperature XRD could not confirm this observation.

  17. Optically pumped cerium-doped LiSrAlF{sub 6} and LiCaAlF{sub 6}

    DOE Patents [OSTI]

    Marshall, C.D.; Payne, S.A.; Krupke, W.F.

    1996-05-14

    Ce{sup 3+}-doped LiSrAlF{sub 6} crystals are pumped by ultraviolet light which is polarized along the c axis of the crystals to effectively energize the laser system. In one embodiment, the polarized fourth harmonic light output from a conventional Nd:YAG laser operating at 266 nm is arranged to pump Ce:LiSrAlF{sub 6} with the pump light polarized along the c axis of the crystal. The Ce:LiSrAlF{sub 6} crystal may be placed in a laser cavity for generating tunable coherent ultraviolet radiation in the range of 280-320 nm. Additionally, Ce-doped crystals possessing the LiSrAlF{sub 6} type of chemical formula, e.g. Ce-doped LiCaAlF{sub 6} and LiSrGaF{sub 6}, can be used. Alternative pump sources include an ultraviolet-capable krypton or argon laser, or ultraviolet emitting flashlamps. The polarization of the pump light will impact operation. The laser system will operate efficiently when light in the 280-320 nm gain region is injected or recirculated in the system such that the beam is also polarized along the c axis of the crystal. The Ce:LiSrAlF{sub 6} laser system can be configured to generate ultrashort pulses, and it may be used to pump other devices, such as an optical parametric oscillator. 10 figs.

  18. Optically pumped cerium-doped LiSrAlF.sub.6 and LiCaAlF.sub.6

    DOE Patents [OSTI]

    Marshall, Christopher D. (Livermore, CA); Payne, Stephen A. (Castro Valley, CA); Krupke, William F. (Pleasanton, CA)

    1996-01-01

    Ce.sup.3+ -doped LiSrAlF.sub.6 crystals are pumped by ultraviolet light which is polarized along the c axis of the crystals to effectively energize the laser system. In one embodiment, the polarized fourth harmonic light output from a conventional Nd:YAG laser operating at 266 nm is arranged to pump Ce:LiSrAlF.sub.6 with the pump light polarized along the c axis of the crystal. The Ce:LiSrAlF.sub.6 crystal may be placed in a laser cavity for generating tunable coherent ultraviolet radiation in the range of 280-320 nm. Additionally, Ce-doped crystals possessing the LiSrAlF.sub.6 type of chemical formula, e.g. Ce-doped LiCaAlF.sub.6 and LiSrGaF.sub.6, can be used. Alternative pump sources include an ultraviolet-capable krypton or argon laser, or ultraviolet emitting flashlamps. The polarization of the pump light will impact operation. The laser system will operate efficiently when light in the 280-320 nm gain region is injected or recirculated in the system such that the beam is also polarized along the c axis of the crystal. The Ce:LiSrAlF.sub.6 laser system can be configured to generate ultrashort pulses, and it may be used to pump other devices, such as an optical parametric oscillator.

  19. Ab initio study of irradiation tolerance for different M{sub n+1}AX{sub n} phases: Ti{sub 3}SiC{sub 2} and Ti{sub 3}AlC{sub 2}

    SciTech Connect (OSTI)

    Zhao, Shijun; Xue, Jianming, E-mail: jmxue@pku.edu.cn; Wang, Yugang [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China); Center for Applied Physics and Technology, Peking University, Beijing 100871 (China); Huang, Qing [Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, Zhejiang (China)

    2014-01-14

    Layered ternary M{sub n+1}AX{sub n} (MAX) materials are recently proposed to be promising candidates for future fission and fusion programmes because of their unique properties inherited from both ceramics and metals. However, different M{sub n+1}AX{sub n} materials demonstrate different behaviors when exposed to energetic neutron or ion irradiations. Based on first-principles calculations, we have investigated the irradiation tolerance of two typical M{sub n+1}AX{sub n} materials: Ti{sub 3}SiC{sub 2} and Ti{sub 3}AlC{sub 2} from two aspects. First, we make a detailed analysis on the interatomic bonding characters, which are believed to be responsible for the resistance to radiation-induced amorphization. Second, the formation energies of various intrinsic and antisite defects in these two compounds are calculated in order to elucidate their amorphization mechanism. Our results show that the absence of orbitals overlap of Al-C in Ti{sub 3}AlC{sub 2} renders it more resistant to amorphization compared to Ti{sub 3}SiC{sub 2}. In addition, the antisite defects Al{sub Ti(1)} and Al{sub Ti(2)} in Ti{sub 3}AlC{sub 2} have much lower formation energies compared to Si{sub Ti(1)} and Si{sub Ti(2)} in Ti{sub 3}SiC{sub 2}, which implies that the replacement of Ti with Al is easier than Si, thus providing an alternative way to accommodate the defects resulted from irradiation damage cascades. These results indicate that Ti{sub 3}AlC{sub 2} is more irradiation tolerant than Ti{sub 3}SiC{sub 2}, in accordance with experimental observations. Our results have profound implications for the choice of appropriate MAX phase with best performance to be used in next reaction reactors.

  20. Structural and magnetic properties and superconductivity in Ba(Fe{sub 1-x}TM{sub x}){sub 2}As{sub 2}

    SciTech Connect (OSTI)

    Thaler, Alexander

    2012-07-23

    We studied the effects on structural and magnetic phase transitions and the emergence of superconductivity in transition metal substituted BaFe{sub 2}As{sub 2}. We grew four series of Ba(Fe{sub 1-x}TM{sub x}){sub 2}As{sub 2} (TM=Ru, Mn, Co+Cr and Co+Mn) and characterized them by crystallographic, magnetic and transport measurements. We also subjected Ba(Fe{sub 1-x}Cr{sub x}){sub 2}As{sub 2} and Ba(Fe{sub 1-x}Co{sub x}){sub 2}As{sub 2} to heat treatment to explore what changes might be induced.

  1. Using HCI Guidelines to Foster Technological Advancement in Sub-Saharan Africa

    E-Print Network [OSTI]

    Stringfellow, Catherine V.

    Using HCI Guidelines to Foster Technological Advancement in Sub-Saharan Africa Jamie Thomas Guidelines to Foster Technological Advancement in Sub-Saharan Africa Jamie Thomas, Midwestern State-Saharan Africa (excluding the region of Southern Africa). There are countless obstacles in the way

  2. SO.sub.2 sensor

    DOE Patents [OSTI]

    Dalla Betta, Ralph A. (Mountain View, CA); Sheridan, David R. (Menlo Park, CA)

    1994-01-01

    This invention is a process for detecting low concentration levels of sulfur oxides (SO.sub.2) in a flowing gas stream (typically a combustion exhaust gas stream) and a catalytic SO.sub.2 sensor system which may be used in that process.

  3. Bifunctional Fe{sub 3}O{sub 4}@Gd{sub 2}O{sub 3}:Eu{sup 3+}nanocomposites obtained by the homogeneous precipitation method

    SciTech Connect (OSTI)

    Peng, Hongxia; Cui, Bin; Wang, Yingsai

    2013-05-15

    Graphical abstract: The TEM images reveal clearly the core–shell structures because of the obvious difference in contrast between the central part and the fringe, which indicates the Gd{sub 2}O{sub 3}:Eu{sup 3+} layer had successfully deposited on the magnetite Fe{sub 3}O{sub 4} cores. And Fe{sub 3}O{sub 4}@Gd{sub 2}O{sub 3}:Eu{sup 3+} nanoparticles keep the spherical morphology, non-aggregation and rough surface. The images reveal that the average diameters of the Fe{sub 3}O{sub 4} and Fe{sub 3}O{sub 4}@Gd{sub 2}O{sub 3}:Eu{sup 3+} nanoparticles are ?200 nm and ?250 nm, respectively. The thickness of Gd{sub 2}O{sub 3}:Eu{sup 3+} layer is ?25 nm. Highlights: ? Fe{sub 3}O{sub 4}@Gd{sub 2}O{sub 3}:Eu{sup 3+} nanocomposites were synthesized by homogeneous precipitation method. ? Formation of core–shell nanostructure revealed by transmission electron microscopy. ? Fe{sub 3}O{sub 4}@Gd{sub 2}O{sub 3}:Eu{sup 3+} nanocomposites showed magnetic behavior and fluorescence properties. ? Possible applications including bioseparation, drug delivery system, bio-labels, etc. - Abstract: An easy homogeneous precipitation method was developed for the synthesis of bifunctional magnetic-fluorescent nanocomposites with Fe{sub 3}O{sub 4} nanoparticles as the core and europium-doped gadolinium oxide (Gd{sub 2}O{sub 3}:Eu{sup 3+}) as the shell. The nanocomposites showed both strong magnetic behavior and unique Eu-related fluorescence properties with a high emission intensity, which may lead to development of nanocomposites with great potential for applications in drug targeting, biosensors, and diagnostic analysis.

  4. 851 S.W. Sixth Avenue, Suite 1100 Steve Crow 503-222-5161 Portland, Oregon 97204-1348 Executive Director 800-452-5161

    E-Print Network [OSTI]

    the Loss-of-Load Expectation (LOLE) work group to develop its planning standards. Unfortunately, NERC funding wasn't sufficient to sustain the work group and so, in 2012, the work group was subsumed an acceptable threshold for such a metric. Summaries, to date, show that seven of the eight NERC sub

  5. Dopant-Induced Nanoscale Electronic Inhomogeneities in Ca<sub>2-xsub>SrxRuO>4sub>

    SciTech Connect (OSTI)

    Zhang, Jiandi; Ismail, #; Moore, R. G.; Wang, S. -C.; Ding, H.; Jin, Rongying; Mandrus, David; Plummer, E Ward

    2006-01-01

    Ca{sub 2-x}Sr{sub x}RuO{sub 4} single crystals with 0.1 {le} x {le} 2.0 have been studied systematically using scanning tunneling microscopy (STM) and spectroscopy, low-energy electron diffraction, and angle resolved photoelectron spectroscopy (ARPES). In contrast with the well-ordered lattice structure, the local density of states at the surface clearly shows a strong doping dependent nanoscale electronic inhomogeneity, regardless of the fact of isovalent substitution. Remarkably, the surface electronic roughness measured by STM and the inverse spectral weight of quasiparticle states determined by ARPES are found to vary with x in the same manner as the bulk in-plane residual resistivity, following the Nordheim rule. For the first time, the surface measurements - especially those with STM - are shown to be in good agreement with the bulk transport results, all clearly indicating a doping-induced electronic disorder in the system.

  6. UF{sub 6} pressure excursions during cylinder heating

    SciTech Connect (OSTI)

    Brown, P.G. [Martin Marietta Energy Systems, Inc., Paducah, KY (United States)

    1991-12-31

    As liquid UF{sub 6} inside a cylinder changes from a liquid to a solid, it forms a porous solid which occupies approximately the same volume as that of the liquid before cooling. Simultaneously as the liquid cools, UF{sub 6} vapor in the cylinder ullage above the liquid desublimes on the upper region of the inner cylinder wall. This solid is a dense, glass-like material which can accumulate to a significant thickness. The thickness of the solid coating on the upper cylinder wall and directly behind the cylinder valve area will vary depending on the conditions during the cooling stage. The amount of time lapsed between UF{sub 6} solidification and UF{sub 6} liquefaction can also affect the UF{sub 6} coating. This is due to the daily ambient heat cycle causing the coating to sublime from the cylinder wall to cooler areas, thus decreasing the thickness. Structural weakening of the dense UF{sub 6} layer also occurs due to cylinder transport vibration and thermal expansion. During cylinder heating, the UF{sub 6} nearest the cylinder wall will liquefy first. As the solid coating behind the cylinder valve begins to liquefy, it results in increased pressure depending upon the available volume for expansion. At the Paducah Gaseous Diffusion Plant (PGDP) during the liquefaction of the UF{sub 6} in cylinders in the UF{sub 6} feed and sampling autoclaves, this pressure increase has resulted in the activation of the systems rupture discs which are rated at 100 pounds per square inch differential.

  7. Structural investigation of the new Ca{sub 3}Ln{sub 2}Ge{sub 3}O{sub 12} (Ln=Pr, Nd, Sm, Gd and Dy) compounds and luminescence spectroscopy of Ca{sub 3}Gd{sub 2}Ge{sub 3}O{sub 12} doped with the Eu{sup 3+} ion

    SciTech Connect (OSTI)

    Piccinelli, F., E-mail: fabio.piccinelli@univr.it [Luminescent Materials Laboratory, DB, Univ. Verona, and INSTM, UdR Verona, Strada Le Grazie 15, 37134 Verona (Italy); Lausi, A. [Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale 14-km 163,5 in AREA Science Park, 34149 Basovizza, Trieste (Italy); Bettinelli, M. [Luminescent Materials Laboratory, DB, Univ. Verona, and INSTM, UdR Verona, Strada Le Grazie 15, 37134 Verona (Italy)

    2013-09-15

    The crystal structures of new rare earth-based germanate compounds (Ca{sub 3}Pr{sub 2}Ge{sub 3}O{sub 12}, Ca{sub 3}Nd{sub 2}Ge{sub 3}O{sub 12}, Ca{sub 3}Sm{sub 2}Ge{sub 3}O{sub 12}, Ca{sub 3}Gd{sub 2}Ge{sub 3}O{sub 12} and Ca{sub 3}Dy{sub 2}Ge{sub 3}O{sub 12}) have been determined by Rietveld refinement calculations on the collected synchrotron X-ray diffraction powder patterns. A different distribution of the rare earth ions in the three available crystal sites was observed, as the main structural feature. The reasons of the instability of the silico-carnotite structure for lanthanide ions out of the range Pr–Dy have been proposed. Finally, the luminescence spectroscopy of the Eu{sup 3+} dopant ion in Ca{sub 3}Gd{sub 2}Ge{sub 3}O{sub 12} was presented and analyzed taking into account the observed structural characteristics. The Eu{sup 3+} luminescence spectroscopy was also compared with the one of Eu{sup 3+} doped Ca{sub 3}Gd{sub 2}Si{sub 3}O{sub 12} and Ca{sub 3}Lu{sub 2}Si{sub 3}O{sub 12} isostructural materials. - Graphical abstract: The structural study on Ca{sub 3}Ln{sub 2}Ge{sub 3}O{sub 12} exploiting synchrotron X-ray diffraction, allows us to determine the detailed geometry of the coordination polyhedra of the metals and their distribution in the crystal sites. These features are, in the case of Ca{sub 3}Gd{sub 2}Ge{sub 3}O{sub 12} host, closely related to the luminescence spectroscopy of the Eu{sup 3+} dopant ion. Display Omitted - Highlights: • The structure of the Ca{sub 3}Ln{sub 2}Ge{sub 3}O{sub 12} (Ln=Pr, Nd, Sm, Gd and Dy) was determined. • Different distribution of Ln{sup 3+} ions on the three available crystal sites was observed. • A detailed structural study focused on the metal coordination polyhedra was performed. • The instability of the silico-carnotite structure out of the range Pr–Dy was discussed. • The luminescence of the dopant Eu{sup 3+} ion in Ca{sub 3}Gd{sub 2}Ge{sub 3}O{sub 12} was presented and analyzed.

  8. Phase diagram and magnetocaloric effects in Ni{sub 50}Mn{sub 35}(In{sub 1?x}Cr{sub x}){sub 15} and (Mn{sub 1?x}Cr{sub x})NiGe{sub 1.05} alloys

    SciTech Connect (OSTI)

    Quetz, Abdiel Muchharla, Baleeswaraiah; Dubenko, Igor; Talapatra, Saikat; Ali, Naushad; Samanta, Tapas; Stadler, Shane

    2014-05-07

    The magnetocaloric and thermomagnetic properties of Ni{sub 50}Mn{sub 35}(In{sub 1?x}Cr{sub x}){sub 15} and (Mn{sub 1?x}Cr{sub x}) NiGe{sub 1.05} systems for 0???x???0.105 and 0???x???0.1, respectively, have been studied by x-ray diffraction, differential scanning calorimetry, and magnetization measurements. Partial substitution of Cr for Mn in (Mn{sub 1?x}Cr{sub x})NiGe{sub 1.05} results in a first order magnetostructural transition from a hexagonal paramagnetic to an orthorhombic paramagnetic phase near T{sub M}???380?K (for x?=?0.07). Partial substitution of Cr for In in Ni{sub 50}Mn{sub 35}(In{sub 1?x}Cr{sub x}){sub 15} shifts the magnetostructural transition to a higher temperature (T?=?T{sub M}???450?K) for x?=?0.1. Large magnetic entropy changes of ?S?=??12 (J/(kgK)) and ?S?=??11 (J/(kgK)), both for a magnetic field change of 5?T, were observed in the vicinity of T{sub M} for (Mn{sub 1?x}Cr{sub x})NiGe{sub 1.05} and Ni{sub 50}Mn{sub 35}(In{sub 1?x}Cr{sub x}){sub 15}, respectively.

  9. Regional Summary Pacific Region Management Context

    E-Print Network [OSTI]

    Pacific Rim nations. As such, the management of the HMS fisheries s coordinated by the Pacific FisheryRegional Summary Pacific Region Management Context The Pacific Region includes California, Oregon, and Washington. Federal fisheries in this region are managed by the Pacific Fishery Management Council (PFMC

  10. Investigating the reversibility of structural modifications of Li<sub>xsub>Ni<sub>yMnzCo>1-y-zsub>O? cathode materials during initial charge/discharge, at multiple length scales

    SciTech Connect (OSTI)

    Hwang, Sooyeon; Bak, Seong -Min; Kim, Seung Min; Chung, Kyung Yoon; Chang, Wonyoung

    2015-08-11

    In this work, we investigate the structural modifications occurring at the bulk, subsurface, and surface scales of Li<sub>xsub>Ni<sub>yMnzCo>1-y-zsub>O? (NMC; y, z = 0.8, 0.1 and 0.4, 0.3, respectively) cathode materials during the initial charge/discharge. Various analytical tools, such as X-ray diffraction, selected-area electron diffraction, electron energy-loss spectroscopy, and high-resolution electron microscopy, are used to examine the structural properties of the NMC cathode materials at the three different scales. Cut-off voltages of 4.3 and 4.8 V are applied during the electrochemical tests as the normal and extreme conditions, respectively. The high-Ni-content NMC cathode materials exhibit unusual behaviors, which is deviate from the general redox reactions during the charge or discharge. The transition metal (TM) ions in the high-Ni-content NMC cathode materials, which are mostly Ni ions, are reduced at 4.8 V, even though TMs are usually oxidized to maintain charge neutrality upon the removal of Li. It was found that any changes in the crystallographic and electronic structures are mostly reversible down to the sub-surface scale, despite the unexpected reduction of Ni ions. However, after the discharge, traces of the phase transitions remain at the edges of the NMC cathode materials at the scale of a few nanometers (i.e., surface scale). This study demonstrates that the structural modifications in NMC cathode materials are induced by charge as well as discharge at multiple length scales. These changes are nearly reversible after the first cycle, except at the edges of the samples, which should be avoided because these highly localized changes can initiate battery degradation.

  11. UFe/sub 4/P/sub 12/ and CeFe/sub 4/P/sub 12/: non-metallic isotypes of superconducting LaFe/sub 4/P/sub 12/

    SciTech Connect (OSTI)

    Meisner, G.P.; Torikachvili, M.S.; Yang, K.N.; Maple, M.B.; Guertin, R.P.

    1984-01-01

    The new compound UFe/sub 4/P/sub 12/, which was found to be isostructural to superconducting LaFe/sub 4/P/sub 12/ and with a lattive constant of 7.7729 A, is a semiconductor and shows ferromagnetic order below 3.15 K. CeFe/sub 4/P/sub 12/ is also a semiconductor and its magnetic susceptibility is unusually small in comparison to LaFe/sub 4/P/sub 12/. The semiconducting behaviors of both UFe/sub 4/P/sub 12/ and CeFe/sub 4/P/sub 12/ seem anomalous and may arise from strong f-electron hybridization.

  12. UFe/sub 4/P/sub 12/ and CeFe/sub 4/P/sub 12/: Nonmetallic isotypes of superconducting LaFe/sub 4/P/sub 12/

    SciTech Connect (OSTI)

    Meisner, G.P.; Torikachvili, M.S.; Yang, K.N.; Maple, M.B.; Guertin, R.P.

    1985-04-15

    The new compound UFe/sub 4/P/sub 12/, which was found to be isostructural to superconducting LaFe/sub 4/P/sub 12/ and have a lattice constant of 7.7729 A, is a semiconductor and shows ferromagnetic order below 3.15 K. CeFe/sub 4/P/sub 12/ is also a semiconductor, and its magnetic susceptibility is unusually small in comparison to LaFe/sub 4/P/sub 12/. The semiconducting behaviors of both UFe/sub 4/P/sub 12/ and CeFe/sub 4/P/sub 12/ seem anomalous and may arise from strong f-electron hybridization.

  13. Combustion synthesized nanocrystalline Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C cathode for lithium-ion batteries

    SciTech Connect (OSTI)

    Nathiya, K.; Bhuvaneswari, D.; Gangulibabu; Kalaiselvi, N.

    2012-12-15

    Graphical abstract: Nanocrystalline Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C compound has been synthesized using a novel corn assisted combustion (CAC) method, wherein the composite prepared at 850 °C is found to exhibit superior physical and electrochemical properties than the one synthesized at 800 °C (Fig. 1). Despite the charge disproportionation of V{sup 4+} and a possible solid solution behavior of Li{sub 3}V{sub 2}(PO{sub 4}){sub 3} cathode upon insertion and de-insertion of Li{sup +} ions, the structural stability of the same is appreciable, even with the extraction of third lithium at 4.6 V (Fig. 2). An appreciable specific capacity of 174 mAh g{sup ?1} with an excellent columbic efficiency (99%) and better capacity retention upon high rate applications have been exhibited by Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C cathode, thus demonstrating the feasibility of CAC method in preparing the title compound to best suit with the needs of lithium battery applications. Display Omitted Highlights: ? Novel corn assisted combustion method has been used to synthesize Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C. ? Corn is a cheap and eco benign combustible fuel to facilitate CAC synthesis. ? Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C exhibits an appreciable specific capacity of 174 mAh g{sup ?1} (C/10 rate). ? Currently observed columbic efficiency of 99% is better than the reported behavior. ? Suitability of Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C cathode up to 10C rate is demonstrated. -- Abstract: Nanocrystalline Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C composite synthesized using a novel corn assisted combustion method at 850 °C exhibits superior physical and electrochemical properties than the one synthesized at 800 °C. Despite the charge disproportionation of V{sup 4+} and a possible solid solution behavior of Li{sub 3}V{sub 2}(PO{sub 4}){sub 3} cathode upon insertion and extraction of Li{sup +} ions, the structural stability of the same is appreciable, even with the extraction of third lithium at 4.6 V. An appreciable specific capacity of 174 mAh g{sup ?1} and better capacity retention upon high rate applications have been exhibited by Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C cathode, thus demonstrating the suitability of the same for lithium-ion battery applications.

  14. Photosensitivity of pulsed laser deposited Ge{sub 20}As{sub 20}Se{sub 60} and Ge{sub 10}As{sub 30}Se{sub 60} amorphous thin films

    SciTech Connect (OSTI)

    Hawlová, P.; Olivier, M.; Verger, F. [Department of Graphic Arts and Photophysics, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 53210 Pardubice (Czech Republic); Nazabal, V. [Chemical Sciences Institute of Rennes (ISCR), Glasses and Ceramics Team, UMR-CNRS 6226, University of Rennes 1, 35042 Rennes Cedex (France); Department of Graphic Arts and Photophysics, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 53210 Pardubice (Czech Republic); N?mec, P., E-mail: petr.nemec@upce.cz [Department of Graphic Arts and Photophysics, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 53210 Pardubice (Czech Republic)

    2013-10-15

    Graphical abstract: - Highlights: • Amorphous Ge{sub 20}As{sub 20}Se{sub 60}/Ge{sub 10}As{sub 30}Se{sub 60} films are fabricated by pulsed laser deposition. • Photosensitivity of the layers is studied by employing spectroscopic ellipsometry. • As-deposited/relaxed thin films were irradiated by 593, 635, and 660 nm lasers. • Ge{sub 20}As{sub 20}Se{sub 60} layers present almost zero photorefraction in relaxed state. - Abstract: Amorphous Ge{sub 20}As{sub 20}Se{sub 60} and Ge{sub 10}As{sub 30}Se{sub 60} thin films are fabricated by pulsed laser deposition. Prepared films are characterized in terms of their morphology, chemical composition, and optical properties. Special attention is given to the photosensitivity of the layers, which was studied by spectroscopic ellipsometry with as-deposited, annealed and exposed films by three different laser sources (593, 635, and 660 nm). The results show better photostability for Ge{sub 20}As{sub 20}Se{sub 60} thin films, where photoinduced change of optical band gap was found to be equal or less than 0.04 eV and these layers present almost zero photorefraction.

  15. Dy-V magnetic interaction and local structure bias on the complex spin and orbital ordering in Dy<sub>1?xsub>TbxVO>3sub> (x=0 and 0.2)

    SciTech Connect (OSTI)

    Yan, J.-Q.; Cao, H. B.; McGuire, M. A.; Ren, Y.; Sales, B. C.; Mandrus, D. G.

    2013-06-01

    The spin and orbital ordering in Dy<sub>1?xsub>TbxVO>3sub> (x=0 and 0.2) was studied by measuring x-ray powder diffraction, magnetization, specific heat, and neutron single-crystal diffraction. The results show that G-OO/C-AF and C-OO/G-AF phases coexist in Dy<sub>0.8sub>Tb>0.20sub>VO>3sub> in the temperature range 2–60 K, and the volume fraction of each phase is temperature and field dependent. The ordering of Dy moments at T*?=?12 K induces a transition from G-OO/C-AF to a C-OO/G-AF phase. Magnetic fields suppress the long-range order of Dy moments and thus the C-OO/G-AF phase below T*. The polarized moments induced at the Dy sublattice by external magnetic fields couple to the V 3d moments, and this coupling favors the G-OO/C-AF state. Also discussed is the effect of the Dy-V magnetic interaction and local structure distortion on the spin and orbital ordering in Dy<sub>1?xsub>TbxVO>3sub>.

  16. A novel organic–inorganic hybrid with Anderson type polyanions as building blocks: (C{sub 6}H{sub 10}N{sub 3}O{sub 2}){sub 2}Na(H{sub 2}O){sub 2}[Al(OH){sub 6}Mo{sub 6}O{sub 18}]·6H{sub 2}O

    SciTech Connect (OSTI)

    Thabet, Safa; Ayed, Brahim; Haddad, Amor

    2012-11-15

    Graphical abstract: Display Omitted Highlights: ? Synthesis of a novel inorganic–organic hybrid compound based on Anderson polyoxomolybdates. ? Characterization by X-ray diffraction, IR and UV–Vis spectroscopies of the new compound. ? Potential applications in catalysis, biochemical analysis and electrical conductivity of the organic–inorganic compound. -- Abstract: A new organic–inorganic hybrid compound based on Anderson polyoxomolybdates, (C{sub 6}H{sub 10}N{sub 3}O{sub 2}){sub 2}Na(H{sub 2}O){sub 2}[Al(OH){sub 6}Mo{sub 6}O{sub 18}]·6H{sub 2}O (1) have been isolated by the conventional solution method and characterized by single-crystal X-ray diffraction, infrared, ultraviolet spectroscopy and Thermogravimetric Analysis (TGA). This compound crystallized in the triclinic system, space group P?1, with a = 94.635(1) ?, b = 10.958(1) ?, c = 11.602(1) ?, ? = 67.525(1)°, ? = 71.049(1)°, ? = 70.124(1)° and Z = 1. The crystal structures of the compounds exhibit three-dimensional supramolecular assembly based on the extensive hydrogen bonding interactions between organic cations, sodium cations, water molecules and Anderson polyoxoanions. The infrared spectrum fully confirms the X-ray crystal structure and the UV spectrum of the title compound exhibits an absorption peak at 210 nm.

  17. Millimeter size single crystals of superconducting YBa.sub.2 Cu.sub.3 O.sub .

    DOE Patents [OSTI]

    Damento, Michael A. (Ames, IA); Gschneidner, Jr., Karl A. (Ames, IA)

    1989-04-25

    A method of growing large, up to 1 mm size single crystals of superconducting YBa.sub.2 Cu.sub.3 O.sub.x, wherein x equals from 6.5 to 7.2.

  18. Millimeter size single crystals of superconducting YBa[sub 2]Cu[sub 3]O[sub x

    DOE Patents [OSTI]

    Damento, M.A.; Gschneidner, K.A. Jr.

    1989-04-25

    A method of growing large, up to 1 mm size single crystals of superconducting YBa[sub 2]Cu[sub 3]O[sub x], wherein x equals from 6.5 to 7.2 is disclosed.

  19. Phonon and magnon scattering of Bi{sub 2}Fe{sub 4}O{sub 9} ceramic

    SciTech Connect (OSTI)

    Sharma, Poorva E-mail: vdinesh33@rediffmail.com; Kumar, Ashwini E-mail: vdinesh33@rediffmail.com; Varshney, Dinesh E-mail: vdinesh33@rediffmail.com

    2014-04-24

    We report the phonon structure of Bi{sub 2}Fe{sub 4}O{sub 9} ceramics as synthesized by solid-state reaction route. Rietveld refined X-ray diffraction patterns confirmed the formation of single-phase perovskite structure and all the peaks of Bi{sub 2}Fe{sub 4}O{sub 9} perfectly indexed to the orthorhombic (space group Pbam). Raman scattering measurements identifies 12A{sub g}+1B{sub 2g}+1B{sub 3g} Raman active optical phonon modes. Apart from phonon scattering, mode at 470 cm{sup ?1} is observed which is due to magnon scattering. The P-E loop infers paraelectric nature of Bi{sub 2}Fe{sub 4}O{sub 9}.

  20. Synthesis, crystal structure and magnetic properties of Li{sub 0.44}Eu{sub 3}[B{sub 3}N{sub 6}

    SciTech Connect (OSTI)

    Kokal, I.; Aydemir, U.; Prots, Yu.; Förster, T.; Sichelschmidt, J.; Yahyaoglu, M.; Auffermann, G.; Schnelle, W.; Schappacher, F.; Pöttgen, R.; Somer, M.

    2014-02-15

    Li{sub 0.44}Eu{sub 3}[B{sub 3}N{sub 6}] was synthesized from the metathesis reaction of Li{sub 3}[BN{sub 2}] and EuCl{sub 3} at 850 °C. Li{sub 0.44}Eu{sub 3}[B{sub 3}N{sub 6}] crystallizes in the trigonal space group R3{sup ¯}c (No. 167) with a=12.0225(2) Å, c=6.8556(2) Å and Z=6. In the crystal structure, isolated, planar cyclic [B{sub 3}N{sub 6}]{sup 9?} units are charge-balanced by the mixed-valence Eu{sup 3+}/Eu{sup 2+} and Li{sup +} cations. Li{sup +} occupies partially (44%) the Wyckoff site 6b and is sandwiched between the [B{sub 3}N{sub 6}]{sup 9?} anions. Mössbauer spectroscopy results show the resonance lines of Eu{sup 2+} and Eu{sup 3+}, respectively, indicating the heterogeneous mixed valency of the Eu atoms. X-Band ESR investigations between 5 and 300 K reveal an intense signal over the whole temperature range originating from Eu{sup 2+}. Magnetic susceptibility measurements indicate a Curie–Weiss behavior with an experimental effective magnetic moment of ?{sub eff}=8.28 ?{sub B} per formula unit. - Graphical abstract: Single crystals of Li{sub 0.44}Eu{sub 3}[B{sub 3}N{sub 6}] was obtained from the metathesis reaction of Li{sub 3}[BN{sub 2}] and EuCl{sub 3.}{sup 151}Eu Mössbauer, ESR and magnetic susceptibility measurements reveal the heterogeneous mixed valency of the Eu atoms. Display Omitted - Highlights: • Single crystals of Li{sub 0.44}Eu{sub 3}[B{sub 3}N{sub 6}] was obtained from the metathesis reaction of Li{sub 3}[BN{sub 2}] and EuCl{sub 3} at 850 °C. • Crystal structure is built up by isolated, planar cyclic [B{sub 3}N{sub 6}]{sup 9?} units which are surrounded by mixed valence Eu{sup 3+}/Eu{sup 2+}. • Li{sup +} occupies partially (44%) the site 6b and is sandwiched between the [B{sub 3}N{sub 6}]{sup 9?} anions. • The {sup 151}Eu Mössbauer spectroscopy, electron spin resonance spectroscopy and magnetic susceptibility measurements confirm the heterogeneous mixed valency of Eu.

  1. The crystal structure and magnetic properties of Ba{sub 2?x}Sr{sub x}Co{sub 2}Fe{sub 12}O{sub 22}

    SciTech Connect (OSTI)

    Cho, Kwang Lae; Rhee, Chan Hyuk; Kim, Chul Sung, E-mail: cskim@kookmin.ac.kr [Department of Physics, Kookmin University, Seoul 136-702 (Korea, Republic of)

    2014-05-07

    We have synthesized the Ba{sub 2?x}Sr{sub x}Co{sub 2}Fe{sub 12}O{sub 22} samples (x?=?0.1, 0.2, 0.3, 0.4, 0.5) by the solid-state reaction method and investigated their crystalline and magnetic properties by X-ray diffractometer (XRD), Mössbauer spectrometer, vibrating sample magnetometer, and network analyzer. XRD patterns show that all samples are rhombohedral with space group R-3m. The lattice constants a{sub 0} and c{sub 0} decrease with Sr substitution due to smaller ion radius of Sr{sup 2+} (1.27?Å) than that of Ba{sup 2+} (1.43?Å). The Mössbauer spectroscopy measurements show that the relative area ratios of Fe ion were maintained constant regardless of the Sr concentration. However, average magnetic hyperfine field slightly increased with the Sr concentration. This observation agrees with the fact that the saturation magnetization (M{sub s}) linearly increases due to the increasing super-exchange interaction, originated from the difference in the ionic radius between Ba{sup 2+} and Sr{sup 2+}. To investigate its properties at high frequency range, all samples were sintered at 1100?°C, and complex permeability and permittivity were measured by network analyzer between 100?MHz and 4?GHz. For x below 0.3, the initial permeability at 100?MHz increases, at higher values of x, its value decreases. Our study shows that magnetic properties of Sr{sup 2+} substitution for Ba{sup 2+} in Y-type hexaferrite as well as low magnetic loss less than 0.1 in 1?GHz band, indicating the potential application of Ba{sub 2?x}Sr{sub x}Co{sub 2}Fe{sub 12}O{sub 22} samples for RF and antenna devices in ultra high frequency band.

  2. Nanostructured Ge{sub 2}Sb{sub 2}Te{sub 5} chalcogenide films produced by laser electrodispersion

    SciTech Connect (OSTI)

    Yavsin, D. A., E-mail: yavsin@mail.ioffe.ru; Kozhevin, V. M.; Gurevich, S. A.; Yakovlev, S. A.; Melekh, B. T.; Yagovkina, M. A.; Pevtsov, A. B. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)

    2014-12-15

    Amorphous nanostructured films of a complex chalcogenide (Ge{sub 2}Sb{sub 2}Te{sub 5}) are produced by laser electrodispersion and their structural and electrical properties are studied. It is found that the characteristic size of Ge{sub 2}Sb{sub 2}Te{sub 5} nanoparticles in the structure of the films is 1.5–5 nm.

  3. Palladium site ordering and the occurrence of superconductivity in Bi{sub 2}Pd{sub 3}Se{sub 2-x}S{sub x}

    SciTech Connect (OSTI)

    Weihrich, R. [Institut fuer Anorganische Chemie, Universitaet Regensburg, Universitaetsstrasse 31, D-93040 Regensburg (Germany); Matar, S.F., E-mail: matar@icmcb-bordeaux.cnrs.f [CNRS, University of Bordeaux, ICMCB, 87 avenue du Docteur A. Schweitzer, F-33600 Pessac (France); Anusca, I.; Pielnhofer, F.; Peter, P.; Bachhuber, F. [Institut fuer Anorganische Chemie, Universitaet Regensburg, Universitaetsstrasse 31, D-93040 Regensburg (Germany); Eyert, V. [Center for Electronic Correlations and Magnetism, Institute for Physics, University of Augsburg, D-86135 Augsburg (Germany)

    2011-04-15

    The crystallographic and electronic structures of compounds related to parkerite (Bi{sub 2}Ni{sub 3}S{sub 2}) are investigated with respect to the recently reported occurrence (Bi{sub 2}Pd{sub 3}Se{sub 2}) and absence (Bi{sub 2}Pd{sub 3}S{sub 2}) of superconductivity. Similarities and differences of the crystal structures are discussed within the series of solid solutions Bi{sub 2}Pd{sub 3}S{sub 2-x}Se{sub x} from powder and single crystal diffraction data. From crystal structure refinements, the question of different structures and settings of parkerite is discussed. Similar and different 2D and 3D partial Pd-Ch (Ch=S, Se) structures are related to half antiperovskite ordering schemes. To investigate the relation of low dimensional structures and the occurrence of superconductivity, electronic structures are analyzed by scalar-relativistic DFT calculations, including site projected DOS, ECOV and Fermi surfaces. -- Graphical abstract: Structure relations for perovskite type BiPd{sub 3}C, BiPd{sub 3/2}Se and BiPd{sub 3/2}S. Display Omitted Research highlights: {yields} Merging crystallographic and electronic structures studies to understand chalcogenides related to parkerite (Bi{sub 2}Ni{sub 3}S{sub 2}). {yields} Investigation in view of recently reported occurrence (Bi{sub 2}Pd{sub 3}Se{sub 2}) and absence (Bi{sub 2}Pd{sub 3}S{sub 2}) of superconductivity. {yields} Relationship of half perovskites with perovskites.

  4. Ternary CaCu{sub 4}P{sub 2}-type pnictides AAg{sub 4}Pn{sub 2} (A=Sr, Eu; Pn=As, Sb)

    SciTech Connect (OSTI)

    Stoyko, Stanislav S.; Khatun, Mansura; Scott Mullen, C. [Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2 (Canada); Mar, Arthur, E-mail: arthur.mar@ualberta.ca [Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2 (Canada)

    2012-08-15

    Four ternary pnictides AAg{sub 4}Pn{sub 2} (A=Sr, Eu; Pn=As, Sb) were prepared by reactions of the elements at 850 Degree-Sign C and their crystal structures were determined from single-crystal X-ray diffraction studies. These silver-containing pnictides AAg{sub 4}Pn{sub 2} adopt the trigonal CaCu{sub 4}P{sub 2}-type structure (Pearson symbol hR21, space group R3-bar m, Z=3; a=4.5555(6) A, c=24.041(3) A for SrAg{sub 4}As{sub 2}; a=4.5352(2) A, c=23.7221(11) A for EuAg{sub 4}As{sub 2}; a=4.7404(4) A, c=25.029(2) A for SrAg{sub 4}Sb{sub 2}; a=4.7239(3) A, c=24.689(2) A for EuAg{sub 4}Sb{sub 2}), which can be derived from the trigonal CaAl{sub 2}Si{sub 2}-type structure of the isoelectronic zinc-containing pnictides AZn{sub 2}Pn{sub 2} by insertion of additional Ag atoms into trigonal planar sites within [M{sub 2}Pn{sub 2}]{sup 2-} slabs built up of edge-sharing tetrahedra. Band structure calculations on SrAg{sub 4}As{sub 2} and SrAg{sub 4}Sb{sub 2} revealed that these charge-balanced Zintl phases actually exhibit no gap at the Fermi level and are predicted to be semimetals. - Graphical abstract: SrAg{sub 4}As{sub 2} and related pnictides adopt a CaCu{sub 4}P{sub 2}-type structure in which additional Ag atoms enter trigonal planar sites within slabs built from edge-sharing tetrahedra. Highlights: Black-Right-Pointing-Pointer AAg{sub 4}Pn{sub 2} are the first Ag-containing members of the CaCu{sub 4}P{sub 2}-type structure. Black-Right-Pointing-Pointer Ag atoms are stuffed in trigonal planar sites within CaAl{sub 2}Si{sub 2}-type slabs. Black-Right-Pointing-Pointer Ag-Ag bonding develops through attractive d{sup 10}-d{sup 10} interactions.

  5. Structure, magnetism, specific heat, and dielectric properties of Eu{sub 2}Ta{sub 2}O{sub 7}

    SciTech Connect (OSTI)

    Kolodiazhnyi, T. Sakurai, H.; Matsushita, Y.

    2014-11-17

    Polycrystalline Eu{sub 2}Ta{sub 2}O{sub 7} containing layered perovskite slabs was prepared and analyzed. Eu{sub 2}Ta{sub 2}O{sub 7} crystallizes in the orthorhombic centrosymmetric Cmcm space group (with unit cell: a?=?3.95156(9), b?=?27.0775(6), and c?=?5.68279(13) Å) isomorphous with high-temperature Sr{sub 2}Ta{sub 2}O{sub 7}. Dielectric measurements reveal that, in contrast to Sr{sub 2}Ta{sub 2}O{sub 7} which is ferroelectric below 166?K, Eu{sub 2}Ta{sub 2}O{sub 7} remains paraelectric down to at least 0.45?K and shows no magneto-dielectric coupling. Magnetic data in the 2–400?K range indicate an antiferromagnetic phase transition with a sharp susceptibility peak at 2.71(5) K. Further analysis using specific heat measurements reveals that the second magnetic phase transition occurs at 1.10(5) K and dominates the spin entropy of the Eu{sup 2+} 4f{sup 7} ions. The possible origin of the two successive magnetic phase transitions in Eu{sub 2}Ta{sub 2}O{sub 7} requires further studies.

  6. Quadruple-layered perovskite (CuCl)Ca{sub 2}NaNb{sub 4}O{sub 13}

    SciTech Connect (OSTI)

    Kitada, A.; Tsujimoto, Y.; Yamamoto, T. [Department of Energy and Hydrocarbon Chemistry, Faculty of Engineering, Kyoto University, Nishikyo, Kyoto 615-8510 (Japan); Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502 (Japan); Kobayashi, Y. [Department of Energy and Hydrocarbon Chemistry, Faculty of Engineering, Kyoto University, Nishikyo, Kyoto 615-8510 (Japan); Narumi, Y. [Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581 (Japan); Institute for Materials Research, Tohoku University, Katahira 2-1-1, Sendai 980-8577 (Japan); Kindo, K. [Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581 (Japan); Aczel, A.A.; Luke, G.M. [Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, L8S 4M1 (Canada); Uemura, Y.J. [Department of Physics, Columbia University, New York, NY 10027 (United States); Kiuchi, Y.; Ueda, Y. [Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581 (Japan); Yoshimura, K. [Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502 (Japan); Ajiro, Y. [Department of Energy and Hydrocarbon Chemistry, Faculty of Engineering, Kyoto University, Nishikyo, Kyoto 615-8510 (Japan); Kageyama, H., E-mail: kage@scl.kyoto-u.ac.jp [Department of Energy and Hydrocarbon Chemistry, Faculty of Engineering, Kyoto University, Nishikyo, Kyoto 615-8510 (Japan); Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502 (Japan); Institute for Integrated Cell-Material Sciences, Kyoto University, Sakyo, Kyoto 606-8501 (Japan); CREST, Japan Science and Technology Agency, Kawaguchi 332-0012 (Japan)

    2012-01-15

    We will present the synthesis, structure and magnetic properties of a new quadruple-layered perovskite (CuCl)Ca{sub 2}NaNb{sub 4}O{sub 13}. Through a topotactic ion-exchange reaction with CuCl{sub 2}, the precursor RbCa{sub 2}NaNb{sub 4}O{sub 13} presumably having an incoherent octahederal tliting changes into (CuCl)Ca{sub 2}NaNb{sub 4}O{sub 13} with a 2a{sub p} Multiplication-Sign 2a{sub p} Multiplication-Sign 2c{sub p} superstructure (tetragonal; a=7.73232(5) A, c=39.2156(4) A). The well-defined superstructure for the ion-exchanged product should be stabilized by the inserted CuCl{sub 4}O{sub 2} octahedral layers that firmly connect with neighboring perovskite layers. Magnetic studies show the absence of long-range magnetic ordering down to 2 K despite strong in-plane interactions. Aleksandrov Prime s group theory and Rietveld refinement of synchrotron X-ray diffraction data suggest the structure to be of I4/mmm space group with in-phase tilting along the a and b axes, a two-tilt system (++0). - Graphical Abstract: We present a quadruple-layered copper oxyhalide (CuCl)Ca{sub 2}NaNb{sub 4}O{sub 13} synthesized through a topotactic ion-exchange reaction of RbCa{sub 2}NaNb{sub 4}O{sub 13} with CuCl{sub 2}. The compound has a well-defined superstructure. Magnetic studies suggest the absence of magnetic order even at 2 K. Highlights: Black-Right-Pointing-Pointer (CuCl)Ca{sub 2}NaNb{sub 4}O{sub 13} was prepared by ion-exchange reaction of RbCa{sub 2}NaNb{sub 4}O{sub 13} with CuCl{sub 2}. Black-Right-Pointing-Pointer Compound has a 2a{sub p} Multiplication-Sign 2a{sub p} Multiplication-Sign 2c{sub p} superstructure (tetragonal; a=7.73 A, c=39.21 A). Black-Right-Pointing-Pointer Such a well-defined superstructure was not observed in the precursor compound. Black-Right-Pointing-Pointer Aleksandrov Prime s theory and Rietveld study suggest a (++0) octahedral tilting (I4/mmm). Black-Right-Pointing-Pointer Magnetic studies revealed the absence of magnetic order down to 2 K.

  7. Structural and optical characterization of Cr{sub 2}O{sub 3} nanostructures: Evaluation of its dielectric properties

    SciTech Connect (OSTI)

    Abdullah, M. M., E-mail: abdullahphyzia@gmail.com [Promising Centre for Sensors and Electronic Devices (PCSED), Najran University, P.O. Box 1988, Najran, 11001 (Saudi Arabia); Department of Physics, College of Science and Arts, Najran University, P.O. Box 1988, Najran, 11001 (Saudi Arabia); Rajab, Fahd M. [Promising Centre for Sensors and Electronic Devices (PCSED), Najran University, P.O. Box 1988, Najran, 11001 (Saudi Arabia) [Promising Centre for Sensors and Electronic Devices (PCSED), Najran University, P.O. Box 1988, Najran, 11001 (Saudi Arabia); Department of Chemical Engineering, College of Engineering, Najran University, P.O. Box 1988, Najran, 11001 (Saudi Arabia); Al-Abbas, Saleh M. [Promising Centre for Sensors and Electronic Devices (PCSED), Najran University, P.O. Box 1988, Najran, 11001 (Saudi Arabia)] [Promising Centre for Sensors and Electronic Devices (PCSED), Najran University, P.O. Box 1988, Najran, 11001 (Saudi Arabia)

    2014-02-15

    The structural, optical and dielectric properties of as-grown Cr{sub 2}O{sub 3} nanostructures are demonstrated in this paper. Powder X-ray diffractometry analysis confirmed the rhombohedral structure of the material with lattice parameter, a = b = 4.953 Å; c = 13.578 Å, and average crystallize size (62.40 ± 21.3) nm. FE-SEM image illustrated the mixture of different shapes (disk, particle and rod) of as-grown nanostructures whereas; EDS spectrum confirmed the elemental purity of the material. FTIR spectroscopy, revealed the characteristic peaks of Cr–O bond stretching vibrations. Energy band gap (3.2 eV) of the nanostructures has been determined using the results of UV-VIS-NIR spectrophotometer. The dielectric properties of the material were checked in the wide frequency region (100Hz-30 MHz). In the low frequency region, the matrix of the dielectric behaves like source as well as sink of electrical energy within the relaxation time. Low value of dielectric loss exhibits that the materials posses good optical quality with lesser defects. The ac conductivity of the material in the high frequency region was found according to frequency power law. The physical-mechanism and the theoretical-interpretation of dielectric-properties of Cr{sub 2}O{sub 3} nanostructures attest the potential candidature of the material as an efficient dielectric medium.

  8. Mechanochemical-thermal preparation and structural studies of mullite-type Bi{sub 2}(Ga{sub x}Al{sub 1-x}){sub 4}O{sub 9} solid solutions

    SciTech Connect (OSTI)

    Da Silva, K.L. [Institute of Physical and Theoretical Chemistry, Technische Universitaet Braunschweig, Hans-Sommer-Str. 10, 38106 Braunschweig (Germany); Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover, Callinstr. 3a, 30167 Hannover (Germany); Department of Physics, State University of Maringa, Av. Colombo 5790, 87020-900 Maringa (Brazil); Sepelak, V., E-mail: vladimir.sepelak@kit.ed [Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Duevel, A. [Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover, Callinstr. 3a, 30167 Hannover (Germany); Paesano, A. [Department of Physics, State University of Maringa, Av. Colombo 5790, 87020-900 Maringa (Brazil); Hahn, H. [Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Litterst, F.J. [Institute of Condensed Matter Physics, Technische Universitaet Braunschweig, Mendelssohnstr. 3, 38106 Braunschweig (Germany); Heitjans, P. [Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover, Callinstr. 3a, 30167 Hannover (Germany); Becker, K.D. [Institute of Physical and Theoretical Chemistry, Technische Universitaet Braunschweig, Hans-Sommer-Str. 10, 38106 Braunschweig (Germany)

    2011-05-15

    A series of Bi{sub 2}(Ga{sub x}Al{sub 1-x}){sub 4}O{sub 9} solid solutions (0{<=}x{<=}1), prepared by mechanochemical processing of Bi{sub 2}O{sub 3}/Ga{sub 2}O{sub 3}/Al{sub 2}O{sub 3} mixtures and subsequent annealing, was investigated by XRD, EDX, and {sup 27}Al MAS NMR. The structure of the Bi{sub 2}(Ga{sub x}Al{sub 1-x}){sub 4}O{sub 9} solid solutions is found to be orthorhombic, space group Pbam (No. 55). The lattice parameters of the Bi{sub 2}(Ga{sub x}Al{sub 1-x}){sub 4}O{sub 9} series increase linearly with increasing gallium content. Rietveld refinement of the XRD data as well as the analysis of the {sup 27}Al MAS NMR spectra show a preference of gallium cations for the tetrahedral sites in Bi{sub 2}(Ga{sub x}Al{sub 1-x}){sub 4}O{sub 9}. As a consequence, this leads to a far from random distribution of Al and Ga cations across the whole series of solid solutions. -- Graphical Abstract: Mullite-type Bi{sub 2}(Ga{sub x}Al{sub 1-x}){sub 4}O{sub 9} mixed crystals (0{<=}x{<=}1) prepared by a combined mechanochemical-thermal route possess a non-random distribution of Ga{sup 3+} and Al{sup 3+} cations over the sites of tetrahedral (T) and octahedral [O] coordination, characterized by the preference of Ga{sup 3+} (Al{sup 3+}) for tetrahedral (octahedral) sites. Display Omitted Highlights: {yields} Bi{sub 2}(Ga{sub x}Al{sub 1-x}){sub 4}O{sub 9} (0{<=}x{<=}1) were synthesized via mechanochemical-thermal route. {yields} The lattice parameters of Bi{sub 2}(Ga{sub x}Al{sub 1-x}){sub 4}O{sub 9} increase linearly with gallium content. {yields} Quantitative information on the cation distribution in Bi{sub 2}(Ga{sub x}Al{sub 1-x}){sub 4}O{sub 9} is derived. {yields} Ga{sup 3+} and Al{sup 3+} show the preference for tetrahedral and octahedral sites, respectively.

  9. Enhanced ferromagnetic order in Sr{sub 4}Mn{sub 3}O{sub 3}(GeO{sub 4}){sub 3} featuring canted [MnO{sub 4}]{sub ?} spin chains of mixed-valent Mn(III)/Mn(IV). Aliovalent substitution of the Sr{sub 4?x}Ln{sub x}Mn{sup III}{sub 2+x}Mn{sup IV}{sub 1?x}O{sub 3}(GeO{sub 4}){sub 3} solid-solution

    SciTech Connect (OSTI)

    West, J. Palmer; Sulejmanovic, Dino; Becht, Gregory; He, Jian; Hitchcock, Dale; Yan, Yonggao; Hwu, Shiou-Jyh

    2013-10-15

    Crystals of Sr{sub 4?x}Ln{sub x}Mn{sub 3}O{sub 3}(GeO{sub 4}){sub 3} (x=0; x?0.15 for Ln=La, Pr, Nd, Sm. Eu, Gd, Dy; x?0.3 for Ln=Gd) were isolated upon using high-temperature, solid-state methods in molten-salt media. These compounds are isostructural with the previously reported Na{sub 3}LnMn{sub 3}O{sub 3}(AsO{sub 4}){sub 3} (Ln=La, Sm, Gd) series that contains the same [MnO{sub 4}]{sub ?} spin chains. The synthesis of the Sr{sub 4}Mn{sub 3}O{sub 3}(GeO{sub 4}){sub 3} (x=0) phase was carried out by a double aliovalent substitution with respect to the Sr{sup 2+} and Ge{sup 4+} ions that replace Na{sup +}/Ln{sup 3+} and As{sup 5+} in Na{sub 3}LnMn{sub 3}O{sub 3}(AsO{sub 4}){sub 3}, respectively. The title series contains mixed-valent Mn(III)/Mn(IV) and shows a limited range of solid solution, both of which were not observed in the previously reported Na{sub 3}LnMn{sub 3}O{sub 3}(AsO{sub 4}){sub 3} series. To form the Sr{sub 4?x}Ln{sub x}Mn{sub 3}O{sub 3}(GeO{sub 4}){sub 3} solid solution, one of the Sr{sup 2+} sites, i.e., the original Ln-site in Na{sub 3}LnMn{sub 3}O{sub 3}(AsO{sub 4}){sub 3}, is partially substituted by Ln{sup 3+} in a statistical disorder of Sr{sub 1?x}/Ln{sub x}. Initial magnetic investigations of selected derivatives reveal higher ferromagnetic ordering temperatures than those reported for the Na{sub 3}LnMn{sub 3}O{sub 3}(AsO{sub 4}){sub 3} series, presumably attributed to a lesser degree of canting as a result of introducing non-Jahn–Teller Mn{sup 4+} ions. Also intriguing is the observation of multiple anomalies at low temperatures which appear to be of electronic origins. - Graphical abstract: Sr{sub 4?x}Ln{sub x}Mn(III){sub 2+x}Mn(IV){sub 1?x}O{sub 3}(GeO{sub 4}){sub 3}. Display Omitted - Highlights: • Double aliovalent substitution: Sr{sub 4}Mn{sub 3}O{sub 3}(GeO{sub 4}){sub 3} with respect to Na{sub 3}LnMn{sub 3}O{sub 3}(AsO{sub 4}){sub 3}. • Solid solution with respect to statistical disorder of Sr{sub 1?x}Ln{sub x} in one of the two Sr sites. • Mn{sup 3+}/Mn{sup 4+} magnetic ions are spatially arranged in a triangular kagomé fashion. • Enhanced ferromagnetic ordering attributed to doping non-Jahn–Teller Mn{sup 4+}.

  10. Ti{sub 5}O{sub 5} superstructures of cubic titanium monoxide

    SciTech Connect (OSTI)

    Gusev, A. I.

    2013-08-15

    A cubic model is proposed for the Ti{sub 5}O{sub 5} (Ti{sub 5} Black-Small-Square O{sub 5}{open_square} {identical_to} Ti{sub 90} Black-Small-Square {sub 18}O{sub 90}{open_square}{sub 18}) superstructure of nonstoichiometric titanium monoxide Ti{sub x}O{sub z} with double imperfection. The unit cell of the cubic Ti{sub 5}O{sub 5} superstructure has the threefold lattice parameter of the unit cell of the basis disordered B1 structure of Ti{sub x}O{sub z} monoxide and belongs to space group Pm 3-bar m . The channel of the disorder-order transition, i.e., Ti{sub x}O{sub z} (space group Fm 3-bar m)-Ti{sub 5}O{sub 5} (space group Pm 3-bar m), includes 75 superstructure vectors of seven stars (k{sub 10}), (k{sub 7}), (k{sub 6(1)}), (k{sub 6(2)}), (k{sub 4(1)}), (k{sub 4(2)}), and (k{sub 1}). The distribution functions of Ti and O atoms over the sites of the cubic Ti{sub 5}O{sub 5} superstructure are calculated. A comparison of the X-ray and electron diffraction data obtained for ordered TiO{sub 1.087} monoxide with the theoretical simulation results supports the existence of the cubic Ti{sub 5}O{sub 5} superstructure. The cubic (space group Pm 3-bar m) Ti{sub 5}O{sub 5} superstructure is shown to be a high-temperature structure relative to the well-known monoclinic (space group C2/m) superstructure of the same type.

  11. Southwest Regional Partnership on Carbon Sequestration

    SciTech Connect (OSTI)

    Brian McPherson

    2006-03-31

    The Southwest Partnership on Carbon Sequestration completed its Phase I program in December 2005. The main objective of the Southwest Partnership Phase I project was to evaluate and demonstrate the means for achieving an 18% reduction in carbon intensity by 2012. Many other goals were accomplished on the way to this objective, including (1) analysis of CO{sub 2} storage options in the region, including characterization of storage capacities and transportation options, (2) analysis and summary of CO{sub 2} sources, (3) analysis and summary of CO{sub 2} separation and capture technologies employed in the region, (4) evaluation and ranking of the most appropriate sequestration technologies for capture and storage of CO{sub 2} in the Southwest Region, (5) dissemination of existing regulatory/permitting requirements, and (6) assessing and initiating public knowledge and acceptance of possible sequestration approaches. Results of the Southwest Partnership's Phase I evaluation suggested that the most convenient and practical ''first opportunities'' for sequestration would lie along existing CO{sub 2} pipelines in the region. Action plans for six Phase II validation tests in the region were developed, with a portfolio that includes four geologic pilot tests distributed among Utah, New Mexico, and Texas. The Partnership will also conduct a regional terrestrial sequestration pilot program focusing on improved terrestrial MMV methods and reporting approaches specific for the Southwest region. The sixth and final validation test consists of a local-scale terrestrial pilot involving restoration of riparian lands for sequestration purposes. The validation test will use desalinated waters produced from one of the geologic pilot tests. The Southwest Regional Partnership comprises a large, diverse group of expert organizations and individuals specializing in carbon sequestration science and engineering, as well as public policy and outreach. These partners include 21 state government agencies and universities, five major electric utility companies, seven oil, gas and coal companies, three federal agencies, the Navajo Nation, several NGOs, and the Western Governors Association. This group is continuing its work in the Phase II Validation Program, slated to conclude in 2009.

  12. Pumping-route-dependent concentration quenching and temperature effect of green up- and down-conversion luminescence in Er{sup 3+}/Yb{sup 3+} co-doped Gd{sub 2}(WO{sub 4}){sub 3} phosphors

    SciTech Connect (OSTI)

    Li, Jingjing; Sun, Jiashi [Department of Physics, Dalian Maritime University, Dalian, Liaoning 116026 (China); Liu, Jutao [College of Life Science, Dalian Nationalities University, Dalian, Liaoning 116600 (China); Li, Xiangping; Zhang, Jinsu [Department of Physics, Dalian Maritime University, Dalian, Liaoning 116026 (China); Tian, Yue [Department of Physics, Dalian Maritime University, Dalian, Liaoning 116026 (China); College of Life Science, Dalian Nationalities University, Dalian, Liaoning 116600 (China); Fu, Shaobo; Cheng, Lihong; Zhong, Haiyang [Department of Physics, Dalian Maritime University, Dalian, Liaoning 116026 (China); Xia, Haiping [Key laboratory of Photo-electronic Materials, Ningbo University, Ningbo, Zhejiang 315211 (China); Chen, Baojiu, E-mail: chenmbj@sohu.com [Department of Physics, Dalian Maritime University, Dalian, Liaoning 116026 (China)

    2013-06-01

    Graphical abstract: A comparative study on the concentration quenching behaviors of green down- and up-conversion emissions was carried out for the first time, and the different concentration quenching mechanisms were analyzed. Secondly, the thermal effect induced by 980 nm LD irradiation was investigated, it was observed that the equilibrium temperature of Gd{sub 2}(WO{sub 4}){sub 3}:Er{sup 3+}/Yb{sup 3+} sample was decided by both the excitation power and Er{sup 3+} doping concentration. Highlights: ? Gd{sub 2}(WO{sub 4}){sub 3}:Er/Yb phosphors were prepared via a co-precipitation reaction. ? Morphology and structure of the phosphors were characterized by XRD and SEM. ? Concentration quenching mechanisms for down and up emissions were studied. ? Thermal effect induced by laser irradiation was studied via temperature sensing tech. - Abstract: Gd{sub 2}(WO{sub 4}){sub 3} phosphors with various Er{sup 3+} concentrations and fixed Yb{sup 3+} concentration were synthesized via a co-precipitation method, and their crystal structure and morphology were characterized by using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The concentration quenching behaviors of green up- and down-conversion emissions of Er{sup 3+} were analyzed, and it was confirmed that the difference between quenching concentration for up- and down-conversion emissions resulted from the different population routes. The temperature sensing properties of the Gd{sub 2}(WO{sub 4}){sub 3}:Er{sup 3+}/Yb{sup 3+} phosphors were studied, and it was found that the Er{sup 3+} doping concentration slightly affected the sensitivity, and Gd{sub 2}(WO{sub 4}){sub 3}:Er{sup 3+}/Yb{sup 3+} phosphors could be used in a broad temperature region for detecting temperature. Finally, the thermal effect induced by 980 nm LD irradiation was investigated, it was observed that the equilibrium temperature of Gd{sub 2}(WO{sub 4}){sub 3}:Er{sup 3+}/Yb{sup 3+} sample was decided by both the excitation power and Er{sup 3+} doping concentration.

  13. Synthetic CO.sub.2 acceptor

    DOE Patents [OSTI]

    Lancet, Michael S. (Pittsburgh, PA); Curran, George P. (Pittsburgh, PA)

    1981-08-18

    A synthetic CO.sub.2 acceptor consisting essentially of at least one compound selected from the group consisting of calcium oxide and calcium carbonate supported in a refractory carrier matrix, the carrier having the general formula Ca.sub.5 (SiO.sub.4).sub.2 CO.sub.3. A method for producing the synthetic CO.sub.2 acceptor is also disclosed.

  14. Ammonium–cobalt–nickel phosphates, NH{sub 4}[Co{sub 1?x}Ni{sub x}PO{sub 4}]·H{sub 2}O

    SciTech Connect (OSTI)

    Torre-Fernández, Laura; Trobajo, Camino [Departamentos de Química Física y Analítica y Química Orgánica e Inorgánica, Universidad de Oviedo-CINN, Oviedo, Asturias 33006 (Spain); Pedro, Imanol de [CITIMAC, Facultad de Ciencias, Universidad de Cantabria, 39005 Santander (Spain); Alfonso, Belén F. [Departamento de Física, Universidad de Oviedo, Oviedo, Asturias 33007 (Spain); Fabelo, Oscar [Institut Laue Langevin, Grenoble, France and Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza, Zaragoza (Spain); Blanco, Jesús A. [Departamento de Física, Universidad de Oviedo, Oviedo, Asturias 33007 (Spain); García, José R., E-mail: jrgm@uniovi.es [Departamentos de Química Física y Analítica y Química Orgánica e Inorgánica, Universidad de Oviedo-CINN, Oviedo, Asturias 33006 (Spain); García-Granda, Santiago [Departamentos de Química Física y Analítica y Química Orgánica e Inorgánica, Universidad de Oviedo-CINN, Oviedo, Asturias 33006 (Spain)

    2013-10-15

    The ammonium–cobalt–nickel phosphates, NH{sub 4}[Co{sub 1?x}Ni{sub x}PO{sub 4}]·H{sub 2}O (x=0.00, 0.34, 0.59, 0.70, 1.00), and the deuterated forms, ND{sub 4}[Co{sub 1?x}Ni{sub x}PO{sub 4}]·D{sub 2}O (x=0.00, 0.38, 0.48, 0.69, 0.85), have been synthesized under mild hydrothermal conditions and characterised using X-ray and neutron diffraction, chemical and thermal analysis, and magnetic measurements. Their crystal structures, including hydrogen positions, were determined by Rietveld refinement using single-crystal X-ray and neutron powder diffraction data. The space group of these orthorhombic crystals modifies as a function of their composition. The magnetic susceptibility and magnetization measurements of these ammonium–cobalt–nickel phosphates show antiferromagnetic behaviour, and the Neel temperature evolves from 5.5 K (x=0.00) up to 13.2 K (x=1.00). - Graphical abstract: We obtained single crystals for all the members of the family. In this series, although all crystals are orthorhombic, the space group changes as a function of the composition, showing how the single-crystal diffraction data is capable to manifest structural subtleties that had not been described before for this group of materials. All the investigated materials behave antiferromagnetically with ordering temperatures from 5.5 K up to 13.2 K. Display Omitted - Highlights: • The ammonium–cobalt–nickel phosphates, NH{sub 4}[Co{sub 1?x}Ni{sub x}PO{sub 4}]·H{sub 2}O (x=0.00, 0.34, 0.59, 0.70, 1.00) and the deuterated forms ND4[Co1-xNixPO4]·D{sub 2}O (x=0.00, 0.38, 0.49, 0.68, 0.85) have synthesized by hydrothermal synthesis. • The structural studies of these compounds are introduced as a function of the composition. • The magnetic studies show an antiferromagnetically behavior with ordering temperatures from 5.5 K to 13.2 K.

  15. Lead (II) selenite halides Pb{sub 3}(SeO{sub 3}){sub 2}X{sub 2} (X = Br, I): Synthesis and crystal structure

    SciTech Connect (OSTI)

    Berdonosov, P. S., E-mail: berdonosov@inorg.chem.msu.ru; Olenev, A. V.; Dolgikh, V. A. [Moscow State University (Russian Federation)

    2012-03-15

    Two lead selenite halides, Pb{sub 3}(SeO{sub 3}){sub 2}Br{sub 2} and Pb{sub 3}(SeO{sub 3}){sub 2}I{sub 2}, have been prepared by solid-phase synthesis and structurally characterized. These compounds are isotypic and can be considered 3D with a microporous framework composed of lead polyhedra (distorted Archimedean antiprisms formed by oxygen and halogen atoms). The framework contains channels oriented in the [010] direction. These channels contain selenium atoms, which are bound with framework oxygen atoms belonging to different lead polyhedra.

  16. Topologically identical, but geometrically isomeric layers in hydrous ?-, ?-Rb[UO{sub 2}(AsO{sub 3}OH)(AsO{sub 2}(OH){sub 2})]·H{sub 2}O and anhydrous Rb[UO{sub 2}(AsO{sub 3}OH)(AsO{sub 2}(OH){sub 2})

    SciTech Connect (OSTI)

    Yu, Na; Klepov, Vladislav V. [Forschungszentrum Jülich GmbH, Institute for Energy and Climate Research (IEK-6), 52428 Jülich (Germany); Villa, Eric M. [Department of Chemistry, Creighton University, 2500 California Plaza, Omaha NE 68178 (United States); Bosbach, Dirk [Forschungszentrum Jülich GmbH, Institute for Energy and Climate Research (IEK-6), 52428 Jülich (Germany); Suleimanov, Evgeny V. [Department of Chemistry, Lobachevsky State University of Nizhny Novgorod, 603950 Nizhny Novgorod (Russian Federation); Depmeier, Wulf [Institut für Geowissenschaften, Universität zu Kiel, 24118 Kiel (Germany); Albrecht-Schmitt, Thomas E., E-mail: albrecht-schmitt@chem.fsu.edu [Department of Chemistry and Biochemistry, Florida State University, 102 Varsity Way, Tallahassee, FL 32306-4390 (United States); Alekseev, Evgeny V., E-mail: e.alekseev@fz-juelich.de [Forschungszentrum Jülich GmbH, Institute for Energy and Climate Research (IEK-6), 52428 Jülich (Germany); Institut für Kristallographie, RWTH Aachen University, 52066 Aachen (Germany)

    2014-07-01

    The hydrothermal reaction of uranyl nitrate with rubidium nitrate and arsenic (III) oxide results in the formation of polymorphic ?- and ?-Rb[UO{sub 2}(AsO{sub 3}OH)(AsO{sub 2}(OH){sub 2})]·H{sub 2}O (?-, ?-RbUAs) and the anhydrous phase Rb[UO{sub 2}(AsO{sub 3}OH)(AsO{sub 2}(OH){sub 2})] (RbUAs). These phases were structurally, chemically and spectroscopically characterized. The structures of all three compounds are based upon topologically identical, but geometrically isomeric layers. The layers are linked with each other by means of the Rb cations and hydrogen bonding. Dehydration experiments demonstrate that water deintercalation from hydrous ?- and ?-RbUAs yields anhydrous RbUAs via topotactic reactions. - Graphical abstract: Three different layer geometries observed in the structures of Rb[UO{sub 2}(AsO{sub 3}OH)(AsO{sub 2}(OH){sub 2})] and ?- and ?- Rb[UO{sub 2}(AsO{sub 3}OH)(AsO{sub 2}(OH){sub 2})]·H{sub 2}O. Two different coordination environments of uranium polyhedra (types I and II) are shown schematically on the top of the figure. - Highlights: • Three new uranyl arsenates were synthesized from the hydrothermal reactions. • The phases consist of the topologically identical but geometrically different layers. • Topotactic transitions were observed in the processes of mono-hyrates dehydration.

  17. Sulfur dioxide gas detection with Na/sub 2/SO/sub 4/-Li/sub 2/SO/sub 4/-Y/sub 2/(SO/sub 4/)/sub 3/-SiO/sub 2/ solid electrolyte by a solid reference electrode method

    SciTech Connect (OSTI)

    Imanaka, N.; Yamaguchi, Y.; Adachi, G.; Shiokawa, J.

    1987-03-01

    The electromotive force (EMF) measurement for a Na/sub 2/SO/sub 4/Li/sub 2/SO/sub 4/-Y/sub 2/(SO/sub 4/)/sub 3/-SiO/sub 2/ solid electrolyte was performed both with NiSO/sub 4/-NiO and CoSO/sub 4/-Co/sub 3/O/sub 4/ solid reference SO/sub 2/ electrodes. The measured EMF coincided well with the calculated EMF for a sulfur dioxide gas concentration from 30 ppm to 1% at 973 K. Good agreement between the measured and calculated EMF was also obtained for the SO/sub 2/ gas content from 100 ppm to 1%, at 923 K with the NiSO/sub 4/-NiO electrode.

  18. Cobalt-doped Bi{sub 26}Mo{sub 10}O{sub 69}: Crystal structure and conductivity

    SciTech Connect (OSTI)

    Mikhailovskaya, Z.A.; Buyanova, E.S.; Petrova, S.A.; Morozova, M.V.; Zhukovskiy, V.M.; Zakharov, R.G.; Tarakina, N.V.; Berger, I.F.

    2013-08-15

    A series of cobalt-doped bismuth molybdates were synthesized and investigated using X-ray powder diffraction, transmission electron microscopy and impedance spectroscopy. The ranges of solid solution were determined. Two new compounds, Bi{sub 1?x}Co{sub x}[Bi{sub 12}O{sub 14}]Mo{sub 5}O{sub 34.5±?} (x=0.2) and Bi[Bi{sub 12}O{sub 14}]Mo{sub 5?y}Co{sub y}O{sub 34.5±?} (y=0.2), which crystallise in monoclinic unit cells have been examined in detail by diffraction methods. Impedance spectroscopy measurements show that the studied materials are good ionic conductors with conductivity values about 5×10{sup ?3} S×cm{sup ?1} at 973 K and 1.7×10{sup ?4} S×cm{sup ?1} at 623 K, which are similar to conductivity values of yttrium substituted zirconia and (YSZ) gadolinium doped ceria (CGO). - Graphical abstract: Measured and calculated diffraction spectra for Bi{sub 12.8}Co{sub 0.2}Mo{sub 5}O{sub 34±?} and projection of the Bi{sub 12.8}Co{sub 0.2}Mo{sub 5}O{sub 34±?} crystal structure onto the ac plane. Highlights: • The limit of the Bi{sub 1?x}Co{sub x}[Bi{sub 12}O{sub 14}]Mo{sub 5}O{sub 34.5±?} homogeneity range is equal to x=0.2. • The limit of the Bi[Bi{sub 12}O{sub 14}]Mo{sub 5?y}Co{sub y}O{sub 34.5±?} homogeneity range is equal to y=0.2. • Solid solutions have monoclinic symmetry. No phase transition is observed. • The conductivity at 700° for y=0.2 solid solutions is equal to ?lg ?, S×cm{sup ?1}=2.23. • The conductivity at 350° for y=0.2 solid solutions is equal to ?lg ?, S×cm{sup ?1}=3.74.

  19. Role of SrMoO{sub 4} in Sr{sub 2}MgMoO{sub 6} synthesis

    SciTech Connect (OSTI)

    Vasala, S.; Yamauchi, H.; Karppinen, M.

    2011-05-15

    Here we investigate the elemental and phase compositions during the solid-state synthesis of the promising SOFC-anode material, Sr{sub 2}MgMoO{sub 6}, and demonstrate that molybdenum does not notably evaporate under the normal synthesis conditions with temperatures up to 1200 {sup o}C due to the formation of SrMoO{sub 4} as an intermediate product at low temperatures, below 600 {sup o}C. However, partial decomposition of the Sr{sub 2}MgMoO{sub 6} phase becomes evident at the higher temperatures ({approx}1500 {sup o}C). The effect of SrMoO{sub 4} on the electrical conductivity of Sr{sub 2}MgMoO{sub 6} is evaluated by preparing a series of Sr{sub 2}MgMoO{sub 6} samples with different amounts of additional SrMoO{sub 4}. Under the reducing operation conditions of an SOFC anode the insulating SrMoO{sub 4} phase is apparently reduced to the highly conductive SrMoO{sub 3} phase. Percolation takes place with 20-30 wt% of SrMoO{sub 4} in a Sr{sub 2}MgMoO{sub 6} matrix, with a notable increase in electrical conductivity after reduction. Conductivity values of 14, 60 and 160 S/cm are determined at 800 {sup o}C in 5% H{sub 2}/Ar for the Sr{sub 2}MgMoO{sub 6} samples with 30, 40 and 50 wt% of added SrMoO{sub 4}, respectively. -- Graphical abstract: SrMoO{sub 4} is formed at low temperatures during the synthesis of Sr{sub 2}MgMoO{sub 6}, which prevents the volatilization of Mo from typical precursor mixtures of this promising SOFC anode material. SrMoO{sub 4} is insulating and it is often found as an impurity in Sr{sub 2}MgMoO{sub 6} samples. It is however readily reduced to highly conducting SrMoO{sub 3}. Composites of Sr{sub 2}MgMoO{sub 6} and SrMoO{sub 3} show increased electrical conductivities compared to pure Sr{sub 2}MgMoO{sub 6} under the reductive operation conditions of an SOFC anode. Display Omitted Highlights: {yields} Sr{sub 2}MgMoO{sub 6} is a promising SOFC anode material. {yields} During the Sr{sub 2}MgMoO{sub 6} synthesis SrMoO{sub 4} is formed at low temperatures. {yields} Formation of SrMoO{sub 4} effectively prevents volatilization of Mo at high temperatures. {yields} Insulating SrMoO{sub 4} reduces to highly conductive SrMoO{sub 3} under SOFC-anode conditions. {yields} Composites of Sr{sub 2}MgMoO{sub 6} and SrMoO{sub 3} show high electrical conductivities.

  20. Proton form factor ratio, {mu}{sub p}G{sub E}{sup P}/G{sub M}{sup P} from double spin asymmetry

    SciTech Connect (OSTI)

    Habarakada Liyanage, Anusha Pushpakumari

    2013-08-01

    The form factors are fundamental properties of the nucleon representing the effect of its structure on its response to electromagnetic probes such as electrons. They are functions of the four-momentum transfer squared Q{sup 2} between the electron and the proton. This thesis reports the results of a new measurement of the ratio of the electric and magnetic form factors of the proton up to Q{sup 2} = 5.66 (GeV/c){sup 2} using the double spin asymmetry with a polarized beam and target. Experiment E07-003 (SANE, Spin Asymmetries of the Nucleon Experiment) was carried out in Hall C at Jefferson Lab in 2009 to study the proton spin structure functions with a dynamically polarized ammonia target and longitudinally polarized electron beam. By detecting elastically scattered protons in the High-Momentum Spectrometer (HMS) in coincidence with the electrons in the Big Electron Telescope Array (BETA), elastic measurements were carried out in parallel. The elastic double spin asymmetry allows one to extract the proton electric to magnetic form factor ratio G{sup p}{sub E}/G{sup p}{sub M} at high-momentum transfer, Q{sup 2} = 5.66 (GeV/c){sup 2}. In addition to the coincidence data, inclusively scattered electrons from the polarized ammonia target were detected by HMS, which allows to measure the beam-target asymmetry in the elastic region with the target spin nearly perpendicular to the momentum transfer, and to extract G{sup p}{sub E}/G{sup p}{sub M} at low Q{sup 2} = 2.06 (GeV/c){sup 2}. This alternative measurement of G{sup p}{sub E}/G{sup p}{sub M} has verified and confirmed the dramatic discrepancy at high Q{sup 2} between the Rosenbluth and the recoil-polarization-transfer iv method with a different measurement technique and systematic uncertainties uncorrelated to those of the recoil-polarization measurements. The measurement of the form factor ratio at Q{sup 2} = 2.06 (GeV/c){sup 2} has been determined as {mu}{sub p}G{sup p}{sub E}/G{sup p}{sub M} = 0.605{+-}0.178{sub stat}{+-}0.033{sub sys} which is in agreement with an earlier measurement with the polarized target technique at similar kinematics. The measurement of the form factor ratio at Q{sup 2} = 5.66 (GeV/c){sup 2} has been determined as {mu}{sub p}G{sup p}{sub E}/G{sup p}{sub M} = 0.672 {+-} 0.362{sub stat} which represents the highest Q{sup 2} reach with the double spin asymmetry to date.

  1. A cluster with a mixed M{sub 6}X{sub 12}/M{sub 6}X{sub 8} environment: The La{sub 6}Cl{sub 11}Co structure

    SciTech Connect (OSTI)

    Zheng Chong; Mattausch, Hansjuergen; Hoch, Constantin; Simon, Arndt

    2009-08-15

    The title compound was synthesized from La, LaCl{sub 3} and Co under Ar atmosphere at 800 deg. C. It crystallizes in space group P4{sub 2}/n (no. 86) with lattice constants a=11.308(2) A and c=14.441(3) A. The structure features an isolated Co-centered La{sub 6} octahedron with all corners and edges, and 2 of its 8 triangular faces coordinated by Cl atoms. The La{sub 6}Co octahedron is significantly distorted, and the La coordination by Cl atoms deviates from the common close-packing arrangements found in other reduced rare earth metal halides. Structure, bonding and physical properties of the compound have been investigated. - Graphical abstract: La{sub 6}Cl{sub 11}Co octahedron exhibiting a mixed M{sub 6}X{sub 12}/M{sub 6}X{sub 12} coordination environment.

  2. SrZn{sub 2}Sn{sub 2} and Ca{sub 2}Zn{sub 3}Sn{sub 6} - two new Ae-Zn-Sn polar intermetallic compounds (Ae: alkaline earth metal)

    SciTech Connect (OSTI)

    Stegmaier, Saskia [Department Chemie, Technische Universitaet Muenchen, Lichtenbergstrasse 4, 85747 Garching (Germany); Faessler, Thomas F., E-mail: Thomas.Faessler@lrz.tum.de [Department Chemie, Technische Universitaet Muenchen, Lichtenbergstrasse 4, 85747 Garching (Germany)

    2012-08-15

    SrZn{sub 2}Sn{sub 2} and Ca{sub 2}Zn{sub 3}Sn{sub 6}, two closely related new polar intermetallic compounds, were obtained by high temperature reactions of the elements. Their crystal structures were determined with single crystal XRD methods, and their electronic structures were analyzed by means of DFT calculations. The Zn-Sn structure part of SrZn{sub 2}Sn{sub 2} comprises (anti-)PbO-like {l_brace}ZnSn{sub 4/4}{r_brace} and {l_brace}SnZn{sub 4/4}{r_brace} layers. Ca{sub 2}Zn{sub 3}Sn{sub 6} shows similar {l_brace}ZnSn{sub 4/4}{r_brace} layers and {l_brace}Sn{sub 4}Zn{r_brace} slabs constructed of a covalently bonded Sn scaffold capped by Zn atoms. For both phases, the two types of layers are alternatingly stacked and interconnected via Zn-Sn bonds. SrZn{sub 2}Sn{sub 2} adopts the SrPd{sub 2}Bi{sub 2} structure type, and Ca{sub 2}Zn{sub 3}Sn{sub 6} is isotypic to the R{sub 2}Zn{sub 3}Ge{sub 6} compounds (R=La, Ce, Pr, Nd). Band structure calculations indicate that both SrZn{sub 2}Sn{sub 2} and Ca{sub 2}Zn{sub 3}Sn{sub 6} are metallic. Analyses of the chemical bonding with the electron localization function (ELF) show lone pair like basins at Sn atoms and Zn-Sn bonding interactions between the layers for both title phases, and covalent Sn-Sn bonding within the {l_brace}Sn{sub 4}Zn{r_brace} layers of Ca{sub 2}Zn{sub 3}Sn{sub 6}. - Graphical abstract: Crystal structures of the new Ae-Zn-Sn polar intermetallic phases SrZn{sub 2}Sn{sub 2} and Ca{sub 2}Zn{sub 3}Sn{sub 6}. Highlights: Black-Right-Pointing-Pointer New polar intermetallic phases SrZn{sub 2}Sn{sub 2} and Ca{sub 2}Zn{sub 3}Sn{sub 6}. Black-Right-Pointing-Pointer Obtained by high temperature reactions of the elements. Black-Right-Pointing-Pointer Single crystal XRD structure determination and DFT electronic structure calculations. Black-Right-Pointing-Pointer Closely related crystal and electronic structures. Black-Right-Pointing-Pointer Metallic conductivity coexisting with lone pairs and covalent bonding features.

  3. Visible light photocatalytic degradation of 4-chlorophenol using vanadium and nitrogen co-doped TiO{sub 2}

    SciTech Connect (OSTI)

    Jaiswal, R.; Kothari, D. C.; Patel, N.; Miotello, A.

    2013-02-05

    Vanadium and Nitrogen were codoped in TiO{sub 2} photocatalyst by Sol-gel method to utilize visible light more efficiently for photocatalytic reactions. A noticeable shift of absorption edge to visible light region was obtained for the singly-doped namely V-TiO{sub 2}, N-TiO{sub 2} and codoped V-N-TiO{sub 2} samples in comparison with undoped TiO{sub 2}, with smallest band gap obtained with codoped-TiO{sub 2}. The photocatalytic activities for all TiO{sub 2} photocatalysts were tested by 4-chlorophenol (organic pollutant) degradation under visible light irradiation. It was found that codoped TiO{sub 2} exhibits the best photocatalytic activity, which could be attributed to the synergistic effect produced by V and N dopants.

  4. GeO{sub 2}/Ge structure submitted to annealing in deuterium: Incorporation pathways and associated oxide modifications

    SciTech Connect (OSTI)

    Bom, N. M.; Soares, G. V.; Hartmann, S.; Bordin, A.; Radtke, C.

    2014-10-06

    Deuterium (D) incorporation in GeO{sub 2}/Ge structures following D{sub 2} annealing was investigated. Higher D concentrations were obtained for GeO{sub 2}/Ge samples in comparison to their SiO{sub 2}/Si counterparts annealed in the same conditions. Oxygen vacancies produced during the annealing step in D{sub 2} constitute defect sites for D incorporation, analogous to defects at the SiO{sub 2}/Si interfacial region. Besides D incorporation, volatilization of the oxide layer is also observed as a consequence of D{sub 2} annealing, especially in the high temperature regime of the present study (>450?°C). In parallel to this volatilization, the stoichiometry and chemical structure of remnant oxide are modified as well. These results evidence the broader impact of forming gas annealing in dielectric/Ge structures with respect to SiO{sub 2}/Si counterparts.

  5. H{sub 2}CO AND N{sub 2}H{sup +} IN PROTOPLANETARY DISKS: EVIDENCE FOR A CO-ICE REGULATED CHEMISTRY

    SciTech Connect (OSTI)

    Qi, Chunhua; Wilner, David J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)] [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Oeberg, Karin I. [Departments of Chemistry and Astronomy, University of Virginia, Charlottesville, VA 22904 (United States)] [Departments of Chemistry and Astronomy, University of Virginia, Charlottesville, VA 22904 (United States)

    2013-03-01

    We present Submillimeter Array (SMA) observations of H{sub 2}CO and N{sub 2}H{sup +} emission in the disks around the T Tauri star TW Hya and the Herbig Ae star HD 163296 at 2''-6'' resolution and discuss the distribution of these species with respect to CO freezeout. The H{sub 2}CO and N{sub 2}H{sup +} emission toward HD 163296 does not peak at the continuum emission center that marks the stellar position but is instead significantly offset. Using a previously developed model for the physical structure of this disk, we show that the H{sub 2}CO observations are reproduced if H{sub 2}CO is present predominantly in the cold outer disk regions. A model where H{sub 2}CO is present only beyond the CO snow line (estimated at a radius of 160 AU) matches the observations well. We also show that the average H{sub 2}CO excitation temperature, calculated from two transitions of H{sub 2}CO observed in these two disks and a larger sample of disks around T Tauri stars in the DISCS (the Disk Imaging Survey of Chemistry with SMA) program, is consistent with the CO freezeout temperature of {approx}20 K. In addition, we show that N{sub 2}H{sup +} and H{sub 2}CO line fluxes in disks are strongly correlated, indicative of co-formation of these species across the sample. Taken together, these results imply that H{sub 2}CO and N{sub 2}H{sup +} are generally present in disks only at low temperatures where CO depletes onto grains, consistent with fast destruction of N{sub 2}H{sup +} by gas-phase CO, and in situ formation of H{sub 2}CO through hydrogenation of CO ice. In this scenario H{sub 2}CO, CH{sub 3}OH, and N{sub 2}H{sup +} emission in disks should appear as rings with the inner edge at the CO midplane snow line. This prediction can be tested directly using observations from ALMA with higher resolution and better sensitivity.

  6. Thermal expansion of Cr{sub 2x}Fe{sub 2-2x}Mo{sub 3}O{sub 12}, Al{sub 2x}Fe{sub 2-2x}Mo{sub 3}O{sub 12} and Al{sub 2x}Cr{sub 2-2x}Mo{sub 3}O{sub 12} solid solutions

    SciTech Connect (OSTI)

    Ari, M.; Jardim, P.M.; Marinkovic, B.A. Rizzo, F.; Ferreira, F.F.

    2008-06-15

    The transition temperature from monoclinic to orthorhombic and the thermal expansion of the orthorhombic phase were investigated for three systems of the family A{sub 2}M{sub 3}O{sub 12}: Cr{sub 2x}Fe{sub 2-2x}Mo{sub 3}O{sub 12}, Al{sub 2x}Fe{sub 2-2x}Mo{sub 3}O{sub 12} and Al{sub 2x}Cr{sub 2-2x}Mo{sub 3}O{sub 12}. It was possible to obtain a single-phase solid solution in all studied samples (x=0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1). A linear relationship between the transition temperature and the fraction of A{sup 3+} cations (x) was observed for each system. In all orthorhombic solid solutions studied here the observed thermal expansion was anisotropic. These anisotropic thermal expansion properties of crystallographic axes a, b and c result in a low positive or near-zero overall linear coefficient of thermal expansion ({alpha}{sub l}={alpha}{sub V}/3). The relationship between the size of A{sup 3+} cations in A{sub 2}M{sub 3}O{sub 12} and the coefficient of thermal expansion is discussed. Near-zero thermal expansion of Cr{sub 2}Mo{sub 3}O{sub 12} is explained by the behavior of Cr-O and Mo-O bond distances, Cr-Mo non-bond distances and Cr-O-Mo bond angles with increasing temperature, estimated by Rietveld analysis of synchrotron X-ray powder diffraction data. - Graphical abstract: In this figure, all published overall linear coefficients of thermal expansion for orthorhombic A{sub 2}M{sub 3}O{sub 12} family obtained through diffraction methods as a function of A{sup 3+} cation radii size, together with dilatometric results, are plotted. Our results indicate that Cr{sub 2}Mo{sub 3}O{sub 12} does not exactly follow the established relationship.

  7. Structural and thermal studies of H{sub 2}La{sub 2/3}Ta{sub 2}O{sub 7}, a protonated layered perovskite

    SciTech Connect (OSTI)

    Le Berre, F.; Crosnier-Lopez, M.P.; Fourquet, J.L.

    2006-04-13

    We have synthesised the new protonated layered perovskite H{sub 2}La{sub 2/3}Ta{sub 2}O{sub 7} which is related to the Ruddlesden-Popper family. This compound is obtained by ionic exchange starting from Li{sub 2}La{sub 2/3}Ta{sub 2}O{sub 7} maintained in dilute HNO{sub 3} at 60 deg. C. Thermal X-ray diffraction and DTA/TGA revealed interesting dehydration properties with formation of a layered anhydrous phase leading at higher temperature (1550 deg. C) to La{sub 1/3}TaO{sub 3}. This latter compound exhibits the original lanthanum ordering expected similarly to that of the Li form, while at 900 deg. C a metastable form, presenting a disordered La distribution, is observed.

  8. Crystal-chemistry of mullite-type aluminoborates Al{sub 18}B{sub 4}O{sub 33} and Al{sub 5}BO{sub 9}: A stoichiometry puzzle

    SciTech Connect (OSTI)

    Fisch, Martin; Armbruster, Thomas; Rentsch, Daniel; Libowitzky, Eugen; Pettke, Thomas

    2011-01-15

    Orthorhombic Al{sub 2}O{sub 3}-rich aluminoborate is an important ceramic material for which two slightly different compositions have been assumed: Al{sub 5}BO{sub 9} (5Al{sub 2}O{sub 3}:B{sub 2}O{sub 3}) and Al{sub 18}B{sub 4}O{sub 33} (9Al{sub 2}O{sub 3}:2B{sub 2}O{sub 3}). The formula Al{sub 18}B{sub 4}O{sub 33} (=Al{sub 4.91}B{sub 1.09}O{sub 9}) was derived from results of chemical analyses when crystal structure data were not yet available. Subsequent structural investigations indicated Al{sub 5}BO{sub 9} composition. Nevertheless, Al{sub 18}B{sub 4}O{sub 33} was still accepted as the correct stoichiometry assuming that additional B replaces 9% Al. Powder samples of both compositions and ones with excess boron were prepared by solid state reactions between {alpha}-Al{sub 2}O{sub 3} and B{sub 2}O{sub 3}/H{sub 3}BO{sub 3} at temperatures above 1100 {sup o}C and single-crystals were grown from flux at 1100 and 1550 {sup o}C. Products were investigated by single-crystal and powder XRD, {sup 11}B and {sup 27}Al solid-state MAS-NMR, Raman and FTIR spectroscopy as well as Laser-ablation ICP-MS. No indication of the predicted 9% B{yields}Al substitution was found. LA ICP-MS indicated 12.36(27) wt% B{sub 2}O{sub 3} corresponding to Al{sub 4.97}B{sub 1.03}O{sub 9}. Hence, the suggested Al{sub 18}B{sub 4}O{sub 33} stoichiometry can be excluded for all synthesized samples. A very low amount of Al vacancies at a five-fold coordinated site are likely, charge balanced by an additional nearby three-fold coordinated B site. All evidences indicate that the title compound should be reported as Al{sub 5-x}B{sub 1+x}O{sub 9} with x<0.038(6), which is close to Al{sub 5}BO{sub 9}. -- Graphical abstract: A chemical composition of Al{sub 18}B{sub 4}O{sub 33}=Al{sub 4.91}B{sub 1.09}O{sub 9}=9Al{sub 2}O{sub 3}:2B{sub 2}O{sub 3} has been assumed for mullite-type aluminoborate with Al{sub 5}BO{sub 9} structure. However, samples prepared by different routes showed compositions close to 5Al{sub 2}O{sub 3}:B{sub 2}O{sub 3}. Display Omitted

  9. Alternative current conduction mechanisms of organic-inorganic compound [N(CH{sub 3}){sub 3}H]{sub 2}ZnCl{sub 4}

    SciTech Connect (OSTI)

    Ben Bechir, M. Karoui, K.; Guidara, K.; Ben Rhaiem, A.; Tabellout, M.

    2014-04-21

    [N(CH{sub 3}){sub 3}H]{sub 2}ZnCl{sub 4} has been studied by X-ray powder diffraction patterns, differential scanning calorimetry (DSC), and impedance spectroscopy. The [N(CH{sub 3}){sub 3}H]{sub 2}ZnCl{sub 4} hybrid compound is crystallized at room temperature (T ? 300?K) in the orthorhombic system with Pnma space group. Five phase transitions (T{sub 1}?=?255?K, T{sub 2}?=?282?K, T{sub 3}?=?302?K, T{sub 4}?=?320?K, and T{sub 5}?=?346?K) have been proved by DSC measurements. The electrical technique was measured in the 10{sup ?1}-10{sup 7}?Hz frequency range and 233–363?K temperature interval. The frequency dependence of alternative current (AC) conductivity is interpreted in terms of Jonscher's law. The AC electrical conduction in [N(CH{sub 3}){sub 3}H]{sub 2}ZnCl{sub 4} is analyzed by different processes, which can be attributed to several models: the correlated barrier hopping model in phase I, the overlapping large polaron tunneling model in phase II, the quantum mechanical tunneling model in phase IV, and the non-overlapping small polaron tunneling model in phases III, V, and VI. The conduction mechanism is studied with the help of Elliot's theory, and the Elliot's parameters are determined.

  10. Alternative current conduction mechanisms of organic-inorganic compound [N(CH{sub 3}){sub 3}H]{sub 2}CuCl{sub 4}

    SciTech Connect (OSTI)

    Ben Bechir, M. Karoui, K.; Guidara, K.; Ben Rhaiem, A.; Tabellout, M.

    2014-05-28

    The [N(CH{sub 3}){sub 3}H]{sub 2}CuCl{sub 4} single crystal has been analyzed by X-ray powder diffraction patterns, differential scanning calorimetry (DSC), and electrical impedance spectroscopy. [N(CH{sub 3}){sub 3}H]{sub 2}CuCl{sub 4} crystallizes at room temperature in the monoclinic system with P2{sub 1}/{sub C} space group. Three phase transitions at T{sub 1}?=?226?K, T{sub 2}?=?264?K, and T{sub 3}?=?297?K have been evidenced by DSC measurements. The electrical technique was measured in the 10{sup ?1}–10{sup 7}?Hz frequency range and 203–313?K temperature intervals. The frequency dependence of alternative current (AC) conductivity is interpreted in terms of Jonscher's law (developed). The AC electrical conduction in [N(CH{sub 3}){sub 3}H]{sub 2}CuCl{sub 4} compound is studied by two processes which can be attributed to a hopping transport mechanism: the correlated barrier hopping model in phases I, II, and III, the non-overlapping small polaron tunneling model in phase IV. The conduction mechanism is interpreted with the help of Elliot's theory, and the Elliot's parameters are found.

  11. Structure and magnetic interactions in the solid solution Ba{sub 3?x}Sr{sub x}Cr{sub 2}O{sub 8}

    SciTech Connect (OSTI)

    Grundmann, Henrik; Schilling, Andreas; Marjerrison, Casey A.; Dabkowska, Hanna A.; Gaulin, Bruce D.

    2013-09-01

    Highlights: • We describe for the first time the preparation of single- and polycrystalline members of the solid solution Ba{sub 3?x}Sr{sub x}Cr{sub 2}O{sub 8}. • We report on the structural changes in the solid solution at room temperature depending on the stoichiometry. • We describe the peculiar change of the magnetic behavior in the solid solution with the stoichiometry. - Abstract: Solid solutions of the magnetic insulators Ba{sub 3}Cr{sub 2}O{sub 8} and Sr{sub 3}Cr{sub 2}O{sub 8} (Ba{sub 3?x}Sr{sub x}Cr{sub 2}O{sub 8}) have been prepared in polycrystalline form for the first time. Single crystalline material was obtained using a mirror image floating zone technique. X-ray diffraction data taken at room temperature indicate that the space group of Ba{sub 3?x}Sr{sub x}Cr{sub 2}O{sub 8} remains unchanged for all values of x, while the cell parameters depend on the chemical composition, as expected. Magnetization data, measured from 300 K down to 2 K, suggest that the interaction constant J{sub d} within the Cr{sup 5+} dimers varies in a peculiar way as a function of x, starting at J{sub d} = 25 K for x = 0, then first slightly dropping to J{sub d} = 18 K for x ? 0.75, before reaching J{sub d} = 62 K for x = 3.

  12. Synthesis, crystal structure, spectroscopic and thermal properties of [Et{sub 4}N][Ta{sub 6}Br{sub 12}(H{sub 2}O){sub 6}]Br{sub 4}.4H{sub 2}O (Et=ethyl)-A new compound with the paramagnetic [Ta{sub 6}Br{sub 12}]{sup 3+} cluster core

    SciTech Connect (OSTI)

    Peric, Berislav; Jozic, Drazan; Planinic, Pavica; Brnicevic, Nevenka; Giester, Gerald

    2009-09-15

    A new hexanuclear cluster compound, [Et{sub 4}N][Ta{sub 6}Br{sub 12}(H{sub 2}O){sub 6}]Br{sub 4}.4H{sub 2}O (Et=ethyl) (1), with the paramagnetic [Ta{sub 6}Br{sub 12}]{sup 3+} cluster entity, was synthesized and characterized by elemental and TG/DTA analyses, IR and UV/Vis spectroscopy and by a single-crystal X-ray diffraction study. The presence of the paramagnetic [Ta{sub 6}Br{sub 12}]{sup 3+} unit was confirmed also by the room-temperature magnetic and EPR measurements. The compound crystallizes in the tetragonal I4{sub 1}/a space group, with a=14.299(5), c=21.241(5) A, Z=4, R{sub 1}(F)/wR{sub 2}(F{sup 2})=0.0296/0.0811. The structure contains discrete [Ta{sub 6}Br{sub 12}(H{sub 2}O){sub 6}]{sup 3+} cations with an octahedron of metal atoms edge-bridged by bromine atoms and with water molecules occupying all six terminal positions. The cluster units are positioned in the vertices of the three-dimensional (pseudo)diamond lattice. The structure shows similarities with literature reported structures of cluster compounds crystallizing in the diamond (Fd3-barm) space group. - Graphical abstract: Two interpenetrating (pseudo)diamond nets formed by packing of the paramagnetic [Ta{sub 6}Br{sub 12}(H{sub 2}O)]{sup 3+} (octahedral) and diamagnetic [Et{sub 4}N]{sup +} (spheres) cations.

  13. F region above kauai: Measurement, model, modification

    SciTech Connect (OSTI)

    Johnson, C.Y.; Sjolander, G.W.; Oran, E.S.; Young, T.R.; Bernhardt, P.A.; Da Rosa, A.V.

    1980-08-01

    A detailed description and analysis is presented of the Lagopedo II results. The rocket was launched on September 11, 1977. Prior to an explosive chemical release a rocket-borne ion mass spectrometer and dual-frequency beacon measured the ion composition and electron content of the undisturbed F region above Kauai, Hawaii. These results are compared to a detailed calculation of ionospheric ion denities. Considerable H/sub 2/O outgassing produced measurable 18/sup +/(H/sub 2/O/sup +/) and 19/sup +/(H/sub 3/O/sup +/) currents which together with O/sup +/ current were used to determine the H/sup 3/O/sup +//H/sub 2/O/sup +/ dissociative recombination rate ratio. The explosive event at 283 km swept clean a l-km-radius region. The boundary of the ionic void was characterized by a steep gradient in the ion density. Results for the first 60 s after the event are presented which show changes in ambient ion species 14/sup +/, 16/sup +/, 30/sup +/, new reactant species 15/sup +/, 17/sup +/, 18/sup +/, 19/sup +/, 27/sup +/, and 46/sup +/, and evidence of ionic depletion by sweeping.

  14. K{sub 2}NaOsO{sub 5.5} and K{sub 3}NaOs{sub 2}O{sub 9}: The first osmium perovskites containing alkali cations at the 'A' site

    SciTech Connect (OSTI)

    Mogare, Kailash M.; Klein, Wilhelm; Jansen, Martin

    2012-07-15

    K{sub 2}NaOsO{sub 5.5} and K{sub 3}NaOs{sub 2}O{sub 9} were obtained from solid-state reactions of potassium superoxide, sodium peroxide and osmium metal at elevated oxygen pressures. K{sub 2}NaOsO{sub 5.5} crystallizes as an oxygen-deficient cubic double perovskite in space group Fm3{sup Macron }m with a=8.4184(5) A and contains isolated OsO{sub 6} octahedra. K{sub 3}NaOs{sub 2}O{sub 9} crystallizes hexagonally in P6{sub 3}/mmc with a=5.9998(4) A and c=14.3053(14) A. K{sub 3}NaOs{sub 2}O{sub 9} consists of face sharing Os{sub 2}O{sub 9} pairs of octahedra. According to magnetic measurements K{sub 2}NaOsO{sub 5.5} is diamagnetic, whereas K{sub 3}NaOs{sub 2}O{sub 9} displays strong antiferromagnetic coupling (T{sub N}=140 K), indicating enhanced magnetic interactions within the octahedral pair. - Graphical abstract: High oxidation states of Os, obtained by high oxygen pressure synthesis, are accommodated in double and triple perovskite matrices. K{sub 3}NaOs{sub 2}O{sub 9} displays enhanced magnetic interactions. Highlights: Black-Right-Pointing-Pointer New osmates containing highly oxidized Os were obtained by high O{sub 2} pressure synthesis. Black-Right-Pointing-Pointer High oxidation states of Os are accommodated in double and triple perovskite matrices. Black-Right-Pointing-Pointer Both compounds represent the first Os perovskites with an alkali metal at the A site. Black-Right-Pointing-Pointer K{sub 3}NaOs{sub 2}O{sub 9} displays enhanced magnetic interactions within the octahedral pair.

  15. Mean field phase diagram of an SU(2){sub {ital L}}{times}SU(2){sub {ital R}} lattice Higgs-Yukawa model at finite {lambda}

    SciTech Connect (OSTI)

    Pryor, C. [Sierra Center for Physics, 939 North Van Ness Avenue, Suite 2, Fresno, California 93728 (United States)] [Sierra Center for Physics, 939 North Van Ness Avenue, Suite 2, Fresno, California 93728 (United States)

    1996-02-01

    The phase diagram of an SU(2){sub {ital L}}{times}SU(2){sub {ital R}} lattice Higgs-Yukawa model with finite {lambda} is constructed using mean field theory. The phase diagram bears a superficial resemblance to that for {lambda}={infinity}; however, as {lambda} is decreased the paramagnetic region shrinks in size. For small {lambda} the phase transitions remain second order, and no new first order transitions are seen. {copyright} {ital 1996 The American Physical Society.}

  16. Measurement of p/sub arrow-up/+p/sub arrow-up/. -->. p+p with a 16. 5-GeV/c polarized proton beam

    SciTech Connect (OSTI)

    Brown, K.A.; Bruni, R.J.; Cameron, P.R.; Crabb, D.G.; Cummings, R.L.; Khiari, F.Z.; Krisch, A.D.; Lin, A.M.T.; Raymond, R.S.; Roser, T.; Terwilliger, K.M.; Danby, G.T.; Ratner, L.G.; Peaslee, D.C.; O'Fallon, J.R.; Roberts, J.B.; Bhatia, T.S.; Northcliffe, L.C.; Simonius, M.

    1985-06-01

    Using the new Brookhaven Alternating Gradient Synchrotron polarized proton beam and our polarized proton target, we measured the spin-spin correlation parameter A/sub n/n in 16.5-GeV/c proton-proton elastic scattering. We found an A/sub n/n of (6.1 +- 3.0)% at P/sub perpendicular/ /sup 2/ = 2.2 (GeV/c)/sup 2/. We also measured the analyzing power A in two independent ways, providing a good test of possible experimental errors. Comparing our new data with 12-GeV Argonne Zero Gradient Synchrotron data shows no evidence for strong energy dependence in A/sub n/n in this medium-P/sub perpendicular/ /sup 2/ region.

  17. Communication: Imaging the effects of the antisymmetric-stretching excitation in the O({sup 3}P) + CH{sub 4}(v{sub 3} = 1) reaction

    SciTech Connect (OSTI)

    Pan, Huilin [Institute of Atomic and Molecular Sciences (IAMS), Academia Sinica, P. O. Box 23-166, Taipei 10617, Taiwan (China) [Institute of Atomic and Molecular Sciences (IAMS), Academia Sinica, P. O. Box 23-166, Taipei 10617, Taiwan (China); State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Liu, Kopin, E-mail: kliu@po.iams.sinica.edu.tw [Institute of Atomic and Molecular Sciences (IAMS), Academia Sinica, P. O. Box 23-166, Taipei 10617, Taiwan (China)] [Institute of Atomic and Molecular Sciences (IAMS), Academia Sinica, P. O. Box 23-166, Taipei 10617, Taiwan (China)

    2014-05-21

    Effects of one-quantum excitation of the antisymmetric-stretching mode of CH{sub 4}(v{sub 3} = 1) on the O({sup 3}P) + CH{sub 4} reaction were studied in a crossed-beam, ion-imaging experiment. In the post-threshold region, we found that (1) the product state distributions are dominated by the CH{sub 3}(0{sub 0}) + OH(v{sup ?} = 1) pair, (2) the product angular distributions extend toward sideways from the backward dominance of the ground-state reaction, and (3) vibrational excitation exerts a positive effect on reactivity, but translational energy is more efficient in promoting the rate of this central-barrier reaction. All major findings agree reasonably well with recent theoretical results. Some remaining questions are pointed out.

  18. Silicon etch using SF{sub 6}/C{sub 4}F{sub 8}/Ar gas mixtures

    SciTech Connect (OSTI)

    Bates, Robert L., E-mail: rlb043000@utdallas.edu [University of Texas at Dallas, Natural Science and Engineering Laboratory (NSERL), Rm. 3.422, P.O. Box 830688, Richardson, Texas 75083 (United States); Stephan Thamban, P. L. [Department of Mechanical Engineering, University of Texas Dallas, Natural Science and Engineering Laboratory (NSERL), P.O. Box 830688, Richardson, Texas 75083 (United States); Goeckner, Matthew J. [Department of Mathematics, University of Texas Dallas, Natural Science and Engineering Laboratory (NSERL), Rm. 3.408, P.O. Box 830688, Mailstop FO35, Richardson, Texas 75083 (United States); Overzet, Lawrence J. [Department of Electrical Engineering, University of Texas Dallas, Natural Science and Engineering Laboratory (NSERL), Rm. 3.404, P.O. Box 830688, Mailstop RH10, Richardson, Texas 75083 (United States)

    2014-07-01

    While plasmas using mixtures of SF{sub 6}, C{sub 4}F{sub 8}, and Ar are widely used in deep silicon etching, very few studies have linked the discharge parameters to etching results. The authors form such linkages in this report. The authors measured the optical emission intensities of lines from Ar, F, S, SF{sub x}, CF{sub 2}, C{sub 2}, C{sub 3}, and CS as a function of the percentage C{sub 4}F{sub 8} in the gas flow, the total gas flow rate, and the bias power. In addition, the ion current density and electron temperature were measured using a floating Langmuir probe. For comparison, trenches were etched of various widths and the trench profiles (etch depth, undercut) were measured. The addition of C{sub 4}F{sub 8} to an SF{sub 6}/Ar plasma acts to reduce the availability of F as well as increase the deposition of passivation film. Sulfur combines with carbon in the plasma efficiently to create a large optical emission of CS and suppress optical emissions from C{sub 2} and C{sub 3}. At low fractional flows of C{sub 4}F{sub 8}, the etch process appears to be controlled by the ion flux more so than by the F density. At large C{sub 4}F{sub 8} fractional flows, the etch process appears to be controlled more by the F density than by the ion flux or deposition rate of passivation film. CF{sub 2} and C{sub 2} do not appear to cause deposition from the plasma, but CS and other carbon containing molecules as well as ions do.

  19. Regional Transportation Coordination Study 

    E-Print Network [OSTI]

    Golden Crescent Regional Planning Commission

    2006-01-01

    stream_source_info Golden Crescent Regional Transportation Coordination Study.pdf.txt stream_content_type text/plain stream_size 357268 Content-Encoding ISO-8859-1 stream_name Golden Crescent Regional Transportation Coordination... Study.pdf.txt Content-Type text/plain; charset=ISO-8859-1 Golden Crescent Regional Transit i Regional Transportation Coordination Study: 7-County Golden Crescent Region Regional...

  20. A novel technique for measurement of thermal rate constants and temperature dependences of dissociative recombination: CO{sub 2}{sup +}, CF{sub 3}{sup +}, N{sub 2}O{sup +}, C{sub 7}H{sub 8}{sup +}, C{sub 7}H{sub 7}{sup +}, C{sub 6}H{sub 6}{sup +}, C{sub 6}H{sub 5}{sup +}, C{sub 5}H{sub 6}{sup +}, C{sub 4}H{sub 4}{sup +}, and C{sub 3}H{sub 3}{sup +}

    SciTech Connect (OSTI)

    Fournier, Joseph A.; Shuman, Nicholas S.; Melko, Joshua J.; Ard, Shaun G.; Viggiano, Albert A.

    2013-04-21

    A novel technique using a flowing afterglow-Langmuir probe apparatus for measurement of temperature dependences of rate constants for dissociative recombination (DR) is presented. Low ({approx}10{sup 11} cm{sup -3}) concentrations of a neutral precursor are added to a noble gas/electron afterglow plasma thermalized at 300-500 K. Charge exchange yields one or many cation species, each of which may undergo DR. Relative ion concentrations are monitored at a fixed reaction time while the initial plasma density is varied between 10{sup 9} and 10{sup 10} cm{sup -3}. Modeling of the decrease in concentration of each cation relative to the non-recombining noble gas cation yields the rate constant for DR. The technique is applied to several species (O{sub 2}{sup +}, CO{sub 2}{sup +}, CF{sub 3}{sup +}, N{sub 2}O{sup +}) with previously determined 300 K values, showing excellent agreement. The measurements of those species are extended to 500 K, with good agreement to literature values where they exist. Measurements are also made for a range of C{sub n}H{sub m}{sup +} (C{sub 7}H{sub 7}{sup +}, C{sub 7}H{sub 8}{sup +}, C{sub 5}H{sub 6}{sup +}, C{sub 4}H{sub 4}{sup +}, C{sub 6}H{sub 5}{sup +}, C{sub 3}H{sub 3}{sup +}, and C{sub 6}H{sub 6}{sup +}) derived from benzene and toluene neutral precursors. C{sub n}H{sub m}{sup +} DR rate constants vary from 8-12 Multiplication-Sign 10{sup -7} cm{sup 3} s{sup -1} at 300 K with temperature dependences of approximately T{sup -0.7}. Where prior measurements exist these results are in agreement, with the exception of C{sub 3}H{sub 3}{sup +} where the present results disagree with a previously reported flat temperature dependence.

  1. Facile synthesis and characterization of ZnFe{sub 2}O{sub 4}/{alpha}-Fe{sub 2}O{sub 3} composite hollow nanospheres

    SciTech Connect (OSTI)

    Shen, Yu [Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China) [Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China); School of Environmental and Chemical Engineering, Dalian Jiaotong University, Dalian 116028 (China); Li, Xinyong, E-mail: xyli@dlut.edu.cn [Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China) [Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China); Department of Chemical Engineering, Curtin University, Perth, WA 6845 (Australia); Zhao, Qidong; Hou, Yang [Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China)] [Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China); Tade, Moses [Department of Chemical Engineering, Curtin University, Perth, WA 6845 (Australia)] [Department of Chemical Engineering, Curtin University, Perth, WA 6845 (Australia); Liu, Shaomin, E-mail: Shaomin.Liu@curtin.edu.au [Department of Chemical Engineering, Curtin University, Perth, WA 6845 (Australia)] [Department of Chemical Engineering, Curtin University, Perth, WA 6845 (Australia)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer ZnFe{sub 2}O{sub 4}/{alpha}-Fe{sub 2}O{sub 3} composite hollow nanospheres were successfully synthesized via a facile method. Black-Right-Pointing-Pointer Detailed structural, morphology and the phase composition were studied. Black-Right-Pointing-Pointer The incorporation of ZnFe{sub 2}O{sub 4} and {alpha}-Fe{sub 2}O{sub 3} gives an appropriate band gap value to utilize solar energy. -- Abstract: ZnFe{sub 2}O{sub 4}/{alpha}-Fe{sub 2}O{sub 3} composite hollow nanospheres were successfully fabricated via a facile one-pot solvothermal method, utilizing polyethylene glycol as soft template. X-ray diffraction and scanning electron microscopy analysis revealed that the prepared nanospheres with cubic spinel and rhombohedra composite structure had a uniform diameter of about 370 nm, and the hollow structure could be further confirmed by transmission electron microscopy. Energy dispersive X-ray, X-ray photoelectron spectroscopy and Fourier transform infrared techniques were also applied to characterize the elemental composition and chemical bonds in the hollow nanospheres. The ZnFe{sub 2}O{sub 4}/{alpha}-Fe{sub 2}O{sub 3} composite hollow nanospheres show attractive light absorption property for potential applications in electronics, optics, and catalysis.

  2. New simple A{sub 4} neutrino model for nonzero {theta}{sub 13} and large {delta}{sub CP}

    SciTech Connect (OSTI)

    Ishimori, Hajime

    2013-05-23

    In a new simple application of the non-Abelian discrete symmetry A{sub 4} to charged-lepton and neutrino mass matrices, we show that for the current experimental central value of sin{sup 2} 2{theta}{sub 13} Asymptotically-Equal-To 0.1, leptonic CP violation is necessarily large, i.e. Double-Vertical-Line tan{delta}{sub CP} Double-Vertical-Line > 1.3. We also consider T{sub 7} model with one parameter to be complex, thus allowing for one Dirac CP phase {delta}{sub CP} and two Majorana CP phases {alpha}{sub 1,2}. We find a slight modification to this correlation as a function of {delta}{sub CP}. For a given set of input values of {Delta}m{sup 2}{sub 21}, {Delta}m{sup 2}{sub 32}, {theta}{sub 12}, and {theta}{sub 13}, we obtain sin{sup 2} 2{theta}{sub 23} and m{sub ee} (the effective Majorana neutrino mass in neutrinoless double beta decay) as functions of tan {delta}{sub CP}. We find that the structure of this model always yields small Double-Vertical-Line tan {delta}{sub CP} Double-Vertical-Line .

  3. Novel yellowish-green emitting luminescence in Ca{sub 7}Si{sub 2}P{sub 2}O{sub 16}:Eu{sup 2+} phosphor

    SciTech Connect (OSTI)

    Wei, Donglei [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China); Interdisciplinary Program of LED and Solid State Lighting Engineering, Pukyong National University, Busan 608-737 (Korea, Republic of); Department of Physics, Pukyong National University, Busan 608-737 (Korea, Republic of); Huang, Yanlin, E-mail: huang@suda.edu.cn [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China); Seo, Hyo Jin, E-mail: hjseo@pknu.ac.kr [Interdisciplinary Program of LED and Solid State Lighting Engineering, Pukyong National University, Busan 608-737 (Korea, Republic of); Department of Physics, Pukyong National University, Busan 608-737 (Korea, Republic of)

    2013-09-01

    Graphical abstract: The phosphor has two separated emission centers with the dependent emission intensity on Eu{sup 2+} doping. There is a red-shift in the emission due to energy transfer with increasing the Eu{sup 2+}-doping. - Highlights: • Green-origin-emitting phosphors of Eu{sup 2+}-doped Ca{sub 7}Si{sub 2}P{sub 2}O{sub 16} were firstly prepared by chemical sol–gel method. • The tunable luminescence color was realized by the changing Eu{sup 2+}-doping in Ca{sub 7}Si{sub 2}P{sub 2}O{sub 16}. • Ca{sub 7}Si{sub 2}P{sub 2}O{sub 16}:Eu{sup 2+} displays two typical luminescence centers with the emission depending on Eu{sup 2+} doping. • Eu{sup 2+}-doped Ca{sub 7}Si{sub 2}P{sub 2}O{sub 16} phosphor has an excellent thermal stability on the temperature quenching. - Abstract: Color tunable green-origin-emitting phosphor of Eu{sup 2+}-doped phosphate-silicate Ca{sub 7}Si{sub 2}P{sub 2}O{sub 16} was prepared by chemical sol–gel method. The X-ray powder diffraction, the photoluminescence excitation and emission spectra, time resolved spectra, and thermal stability were measured. The excitation spectra can well match with the emission light of near UV-LED chips (360–400 nm). The tunable luminescence was realized by changing Eu{sup 2+}-doping concentration. Ca{sub 7}Si{sub 2}P{sub 2}O{sub 16}:Eu{sup 2+} displays two typical luminescence centers, which were suggested to originate from two Ca{sup 2+} sites in the host. With increasing Eu{sup 2+} doping concentrations, the green emission band shifts to long wavelength. Energy transfer between the two different Eu{sup 2+} ions is discussed by analyzing the photoluminescence excitation and emission spectra, concentration-dependent luminescence intensity, and lifetimes. The dependence of the luminescence intensity of Ca{sub 7}Si{sub 2}P{sub 2}O{sub 16}:Eu{sup 2+} on temperatures was measured. The activation energy (?E) for thermal quenching was reported.

  4. Microstructures and properties of CH{sub 3}NH{sub 3}PbI{sub 3?x}Cl{sub x} hybrid solar cells

    SciTech Connect (OSTI)

    Suzuki, Kohei E-mail: oku@mat.usp.ac.jp; Suzuki, Atsushi E-mail: oku@mat.usp.ac.jp; Zushi, Masahito E-mail: oku@mat.usp.ac.jp; Oku, Takeo E-mail: oku@mat.usp.ac.jp

    2015-02-27

    Halide-perovskite CH{sub 3}NH{sub 3}PbI{sub 3} was produced on mesoporous TiO{sub 2} layer by spin-coating a precursor solution of PbCl{sub 2} and CH{sub 3}NH{sub 3}I in dimethylformamide. The role of the annealing process and chlorine (Cl) doping for the perovskite-phase formation was investigated. It was found that crystallization of the perovskite materials was stimulated by the annealing process, and that longer annealing time is necessary for the Cl-doped perovskite compared with that of non-doped perovskite phase.

  5. Hysteretic electrical transport in BaTiO{sub 3}/Ba{sub 1?x}Sr{sub x}TiO{sub 3}/Ge heterostructures

    SciTech Connect (OSTI)

    Ngai, J. H.; Kumah, D. P.; Walker, F. J.; Ahn, C. H.

    2014-02-10

    We present electrical transport measurements of heterostructures comprised of BaTiO{sub 3} and Ba{sub 1?x}Sr{sub x}TiO{sub 3} epitaxially grown on Ge. Sr alloying imparts compressive strain to the BaTiO{sub 3}, which enables the thermal expansion mismatch between BaTiO{sub 3} and Ge to be overcome to achieve c-axis oriented growth. The conduction bands of BaTiO{sub 3} and Ba{sub 1?x}Sr{sub x}TiO{sub 3} are nearly aligned with the conduction band of Ge, which facilitates electron transport. Electrical transport measurements through the dielectric stack exhibit rectifying behavior and hysteresis, where the latter is consistent with ferroelectric switching.

  6. Synthesis, structure and chemical bonding of CaFe{sub 2?x}Rh{sub x}Si{sub 2} (x=0, 1.32, and 2) and SrCo{sub 2}Si{sub 2}

    SciTech Connect (OSTI)

    Hlukhyy, Viktor Hoffmann, Andrea V.; Fässler, Thomas F.

    2013-07-15

    The finding of superconductivity in Ba{sub 0.6}K{sub 0.4}Fe{sub 2}As{sub 2} put the attention on the investigation of compounds that crystallize with ThCr{sub 2}Si{sub 2} structure type such as AT{sub 2}X{sub 2} (A=alkali/alkaline earth/rare earth element; T=transition metal and X=element of the 13–15th group). In this context the silicides CaFe{sub 2}Si{sub 2}, CaFe{sub 0.68(6)}Rh{sub 1.32(6)}Si{sub 2}, CaRh{sub 2}Si{sub 2} and SrCo{sub 2}Si{sub 2} have been synthesized by reaction of the elements under an argon atmosphere. Single crystals were obtained by special heat treatment in welded niobium/tantalum ampoules. The compounds were investigated by means of powder and single crystal X-ray diffraction. All compounds crystallize in the ThCr{sub 2}Si{sub 2}-type structure with space group I4/mmm (No. 139): a=3.939(1) Å, c=10.185(1) Å, R{sub 1}=0.045, 85 F{sup 2} values, 8 variable parameters for CaFe{sub 2}Si{sub 2}; a=4.0590(2) Å, c=9.9390(8) Å, R{sub 1}=0.030, 90 F{sup 2} values, 10 variable parameters for CaFe{sub 0.68(6)}Rh{sub 1.32(6)}Si{sub 2}; a=4.0695(1) Å, c=9.9841(3) Å, R{sub 1}=0.031, 114 F{sup 2} values, 9 variable parameters for CaRh{sub 2}Si{sub 2}; and a=3.974(1) Å, c=10.395(1) Å, R{sub 1}=0.036, 95 F{sup 2} values, 8 variable parameters for SrCo{sub 2}Si{sub 2}. The structure of SrCo{sub 2}Si{sub 2} contains isolated [Co{sub 2}Si{sub 2}]{sup 2?} 2D-layers in the ab-plane whereas in CaFe{sub 2?x}Rh{sub x}Si{sub 2} the [T{sub 2}Si{sub 2}] layers (T=Fe and Rh) are interconnected along the c-axis via Si3Si bonds resulting in a three-dimentional (3D) [T{sub 2}Si{sub 2}]{sup 2?} polyanions and therefore belong to the so-called collapsed form of the ThCr{sub 2}Si{sub 2}-type structure. The SrCo{sub 2}Si{sub 2} and CaRh{sub 2}Si{sub 2} are isoelectronic to the parent 122 iron–pnictide superconductors AeFe{sub 2}As{sub 2} (Ae=alkaline earth elements), whereas CaFe{sub 2}Si{sub 2} is a full substituted variant (As/Si) of CaFe{sub 2}As{sub 2}. The crystal chemistry and chemical bonding in the title compounds are discussed in terms of LMTO band structure calculations and a topological analysis using the Electron Localization Function (ELF). - Graphical abstract: The SrCo{sub 2}Si{sub 2} and CaFe{sub 2?x}Rh{sub x}Si{sub 2} (x==0, 1.32, and 2) crystallize in the ThCr{sub 2}Si{sub 2}-type. The structure of SrCo{sub 2}Si{sub 2} contains isolated [Co{sub 2}Si{sub 2}]{sup 2?} layers in the ab-plane, whereas the [T{sub 2}Si{sub 2}] layers in CaFe{sub 2?x}Rh{sub x}Si{sub 2} are interconnected along the c-axis via Si3Si bonds resulting in a [T{sub 2}Si{sub 2}]{sup 2?} network. - Highlights: • Synthesis and structure of ternary silicides SrCo{sub 2}Si{sub 2} and CaFe{sub 2?x}Rh{sub x}Si{sub 2} (x=0, 1.32, and 2). • The SrCo{sub 2}Si{sub 2} and CaRh{sub 2}Si{sub 2} are isoelectronic to the parent 122 iron–pnictide superconductors AeFe{sub 2}As{sub 2}. • CaFe{sub 2}Si{sub 2} is a full substituted variant (As/Si) of superconductor CaFe{sub 2}As{sub 2}. • The title compounds demonstrate the tunable Si3Si distances.

  7. Dynamics of the reaction of C{sub 3}(a{sup 3}?{sub u}) radicals with C{sub 2}H{sub 2}: A new source for the formation of C{sub 5}H

    SciTech Connect (OSTI)

    Huang, Wen-Jian; Sun, Yi-Lun; Chin, Chih-Hao; Lee, Shih-Huang

    2014-09-28

    The reaction C{sub 3}(a{sup 3}?{sub u}) + C{sub 2}H{sub 2} ? C{sub 5}H + H was investigated at collision energy 10.9 kcal mol{sup ?1} that is less than the enthalpy of ground-state reaction C{sub 3}(X{sup 1}?{sub g}{sup +}) + C{sub 2}H{sub 2} ? C{sub 5}H + H. C{sub 3}(a{sup 3}?{sub u}) radicals were synthesized from 1% C{sub 4}F{sub 6}/He by pulsed high-voltage discharge. The title reaction was conducted in a crossed molecular-beam apparatus equipped with a quadrupole-mass filter. Product C{sub 5}H was interrogated with time-of-flight spectroscopy and synchrotron vacuum-ultraviolet ionization. Reactant C{sub 3}(a{sup 3}?{sub u}) and product C{sub 5}H were identified using photoionization spectroscopy. The ionization thresholds of C{sub 3}(X{sup 1}?{sub g}{sup +}) and C{sub 3}(a{sup 3}?{sub u}) are determined as 11.6 ± 0.2 eV and 10.0 ± 0.2 eV, respectively. The C{sub 5}H product is identified as linear pentynylidyne that has an ionization energy 8.4 ± 0.2 eV. The title reaction releases translational energy 10.6 kcal mol{sup ?1} in average and has an isotropic product angular distribution. The quantum-chemical calculation indicates that the C{sub 3}(a{sup 3}?{sub u}) radical attacks one of the carbon atoms of C{sub 2}H{sub 2} and subsequently a hydrogen atom is ejected to form C{sub 5}H + H, in good agreement with the experimental observation. As far as we are aware, the C{sub 3}(a{sup 3}?{sub u}) + C{sub 2}H{sub 2} reaction is investigated for the first time. This work gives an implication for the formation of C{sub 5}H from the C{sub 3}(a{sup 3}?{sub u}) + C{sub 2}H{sub 2} reaction occurring in a combustion or discharge process of C{sub 2}H{sub 2}.

  8. Adventures on the C<sub>3sub>H>5sub>O potential energy surface: OH+propyne, OH+allene and related reactions

    SciTech Connect (OSTI)

    Zádor, Judit; Miller, James A.

    2014-06-25

    We mapped out the stationary points and the corresponding conformational space on the C<sub>3sub>H>5sub>O potential energy surface relevant for the OH + allene and OH + propyne reactions systematically and automatically using the KinBot software at the UCCSD(T)-F12b/cc-pVQZ-F12//M06-2X/6-311++G(d,p) level of theory. We used RRKM-based 1-D master equations to calculate pressure- and temperature-dependent, channel-specific phenomenological rate coefficients for the bimolecular reactions propyne + OH and allene + OH, and for the unimolecular decomposition of the CH<sub>3sub>CCHOH, CH<sub>3sub>C(OH)CH, CH<sub>2sub>CCH>2sub>OH, CH<sub>2sub>C(OH)CH>2sub> primary adducts, and also for the related acetonyl, propionyl, 2-methylvinoxy, and 3-oxo-1-propyl radicals. The major channel of the bimolecular reactions at high temperatures is the formation propargyl + H<sub>2sub>O, which makes the title reactions important players in soot formation at high temperatures. However, below ~1000 K the chemistry is more complex, involving the competition of stabilization, isomerization and dissociation processes. We found that the OH addition to the central carbon of allene has a particularly interesting and complex pressure dependence, caused by the low-lying exit channel to form ketene + CH<sub>3sub> bimolecular products. In this study, we compared our results to a wide range of experimental data and assessed possible uncertainties arising from certain aspects of the theoretical framework.

  9. New hypodiphosphates of the alkali metals: Synthesis, crystal structure and vibrational spectra of the hypodiphosphates(IV) M{sub 2}[(H{sub 2}P{sub 2}O{sub 6})(H{sub 4}P{sub 2}O{sub 6})] (M=Rb and Cs)

    SciTech Connect (OSTI)

    Wu, Peng [Institut fuer Anorganische und Analytische Chemie der TU Clausthal, Paul-Ernst-Strasse 4, D-38678 Clausthal-Zellerfeld (Germany)] [Institut fuer Anorganische und Analytische Chemie der TU Clausthal, Paul-Ernst-Strasse 4, D-38678 Clausthal-Zellerfeld (Germany); Wiegand, Thomas; Eckert, Hellmut [Institut fuer Physikalische Chemie and Graduate School of Chemistry, Westfaelische Wilhelms-Universitaet Muenster, Corrensstr. 28/30, D-48149 Muenster (Germany)] [Institut fuer Physikalische Chemie and Graduate School of Chemistry, Westfaelische Wilhelms-Universitaet Muenster, Corrensstr. 28/30, D-48149 Muenster (Germany); Gjikaj, Mimoza, E-mail: mimoza.gjikaj@tu-clausthal.de [Institut fuer Anorganische und Analytische Chemie der TU Clausthal, Paul-Ernst-Strasse 4, D-38678 Clausthal-Zellerfeld (Germany)] [Institut fuer Anorganische und Analytische Chemie der TU Clausthal, Paul-Ernst-Strasse 4, D-38678 Clausthal-Zellerfeld (Germany)

    2012-10-15

    The new hypodiphosphates(IV) Rb{sub 2}[(H{sub 2}P{sub 2}O{sub 6})(H{sub 4}P{sub 2}O{sub 6})] (1) and Cs{sub 2}[(H{sub 2}P{sub 2}O{sub 6})(H{sub 4}P{sub 2}O{sub 6})] (2) were synthesized by soft chemistry reactions from aqueous solutions of hypophosphoric acid and the corresponding heavy alkali-metal carbonates. Their crystal structures were determined by single crystal X-ray diffraction. Both compounds crystallize isotypic in the triclinic space group P-1 with one formula unit in the unit cell. The structures are built up by discrete (H{sub 2}P{sub 2}O{sub 6}){sup 2-} and (H{sub 4}P{sub 2}O{sub 6}) units in staggered conformation for the P{sub 2}O{sub 6} skeleton and the corresponding alkali-metal cations. In the (H{sub 2}P{sub 2}O{sub 6}){sup 2-} ion the hydrogen atoms are in a 'trans-trans' conformation. O{center_dot}H-O hydrogen bonds between the (H{sub 2}P{sub 2}O{sub 6}){sup 2-} and (H{sub 4}P{sub 2}O{sub 6}) groups consolidate the structures into a three-dimensional network. The FT-Raman and {sup 31}P and {sup 1}H and MAS NMR spectra of the title compounds have been recorded and interpreted, especially with respect to their assignment to the (H{sub 2}P{sub 2}O{sub 6}){sup 2-} and (H{sub 4}P{sub 2}O{sub 6}) groups. Thermogravimetric data of 2 have been interpreted in terms of a thermal decomposition model. - Graphical Abstract: The layered compounds Rb{sub 2}[(H{sub 2}P{sub 2}O{sub 6})(H{sub 4}P{sub 2}O{sub 6})] and Cs{sub 2}[(H{sub 2}P{sub 2}O{sub 6})(H{sub 4}P{sub 2}O{sub 6})] have been synthesized and investigated. Both crystallize isotypic. The structures are built up by discrete (H{sub 2}P{sub 2}O{sub 6}){sup 2-} and (H{sub 4}P{sub 2}O{sub 6}) units and the corresponding alkali-metal cations. Highlights: Black-Right-Pointing-Pointer Synthesis and single-crystal structure of new alkali hypodiphosphates. Black-Right-Pointing-Pointer Structures are characterized by [(H{sub 2}P{sub 2}O{sub 6})(H{sub 4}P{sub 2}O{sub 6})]{sup 2-} units and M{sup +} cations. Black-Right-Pointing-Pointer (H{sub 2}P{sub 2}O{sub 6}){sup 2-} and (H{sub 4}P{sub 2}O{sub 6}) units are linked by short hydrogen bonds. Black-Right-Pointing-Pointer Both compounds are characterized by {sup 31}P MAS-NMR spectra.

  10. Keggin (K{sub 5}, H{sub 3}O)[SiV{sub 3}W{sub 9}O{sub 40}H]·xH{sub 2}O: Characterization and crystal structure

    SciTech Connect (OSTI)

    Bonfim, Rodrigo de Paiva Floro; Moura, Luiza Cristina de; Eon, Jean-Guillaume; Mentré, Olivier; Vezin, Hervé; Caldarelli, Stefano

    2014-05-01

    Single crystals of the potassium salt (K{sub 5}, H{sub 3}O)[SiV{sub 3}W{sub 9}O{sub 40}H]·xH{sub 2}O of the vanadium tri-substituted ?-Keggin dodecatungstosilicate were prepared and analyzed by vibrational, EPR and {sup 51}V NMR spectroscopy. Varying the synthesis conditions allows crystallization of partially reduced anions. The crystal structure was determined for both oxidized (V{sup 5+}) and partially reduced (V{sup 4+/5+}) potassium salts. Single crystal X-ray diffraction data and solid state {sup 51}V-NMR spectra confirm the occurrence of a single vanadium site in a cubic structure due to rotational disorder of the Keggin ion. Partially reduced compounds crystallize within the same structure as fully oxidized ones. EPR experiments confirm strong interaction of V{sup 4+} with two V{sup 5+} ions, in accordance with insertion of a V{sub 3} subunit into the lacunary Keggin ion as designed in the synthesis method. The 3D-edifice is composed of K{sup +}/H{sub 2}O counter-sublattice with evidence of tunable water occupancy. - Graphical abstract: Relative arrangements of HPA clusters in (K{sub 5}, H{sub 3}O)[SiV{sub 3}W{sub 9}O{sub 40}]·xH{sub 2}O. - Highlights: • We prepared single crystals of the potassium salt (K{sub 5}, H{sub 3}O)[SiV{sub 3}W{sub 9}O{sub 40}H]·xH{sub 2}O. • The synthesis was designed to give the ?-1,2,3-[SiV{sub 3}W{sub 9}O{sub 40}] Keggin ion. • Strict pH control was necessary to avoid vanadium partial reduction. • Reduced compounds crystallize within the same structure as fully oxidized ones. • EPR confirms strong interaction of V{sup 4+} with two V{sup 5+} ions in a V{sub 3} subunit.

  11. Emerging NO sub x /SO sub x control technologies

    SciTech Connect (OSTI)

    Livengood, C.D. (Argonne National Lab., IL (United States)); Markussen, J.M. (USDOE Pittsburgh Energy Technology Center, PA (United States))

    1992-01-01

    The development of advanced flue-gas-cleanup (FGC) technologies fro the control of sulfur dioxide (SO{sub 2}) and nitrogen oxides (NO{sub x}) emissions continues to be a very active area of research and development, both in this country and abroad. This activity is driven both by legislation (such as the recent revisions to the Clean Air Act) and by the desire to develop technologies that surpass current options in terms of performance, costs, operability, and waste/by-product properties. New issues, such as concern over global climate changes and the health effects of toxic air emissions ( air toxics''), are also helping to shape and prioritize the development programs. This paper provides a status report on a number of integrated FGC systems that have reached a significant stage of development, focusing on post-combustion processes that have been rested or are ready for testing at the pilot scale or larger. While some information that was presented at the 1991 CIBO NO{sub x} IV Control Conference is repeated for the sake of completeness, we have updated each section to reflect the most recent reported developments. Although a wide variety of technologies is discussed, it should be noted that there are a number of other integrated approaches, such as slagging combustors, fluidized-bed combustion, gasification/combined-cycle systems, and various processes combining low-NO{sub x} burners with SO{sub 2}-sorbent injection in the furnace. These other approaches also offer features that should not be overlooked when evaluating alternatives for a specific application.

  12. Properties measurements of (U{sub 0.7}Pu{sub 0.3})O{sub 2-x} in PO{sub 2}-controlled atmosphere

    SciTech Connect (OSTI)

    Kato, M.; Murakami, T.; Sunaoshi, T.; Nelson, A.T.; McClellan, K.J.

    2013-07-01

    The investigation of physical properties of uranium and plutonium mixed oxide (MOX) fuels is important for the development of fast reactor fuels. It is well known that MOX is a nonstoichiometric oxide, and the physical properties change drastically with the Oxygen-to-Metal (O/M) ratio. A control technique for O/M ratio was established for measurements of high temperature properties of uranium and plutonium mixed oxide fuels. Sintering behavior, thermal expansion and O/M change of (U{sub 0.7}Pu{sub 0.3})O{sub 2.00} and (U{sub 0.7}Pu{sub 0.3})O{sub 1.99} were investigated in PO{sub 2}-controlled atmosphere which was controlled by H{sub 2}/H{sub 2}O gas system. Sintering behavior changed drastically with O/M ratio, and shrinkage of (U{sub 0.7}Pu{sub 0.3})O{sub 2.00} was faster and more advanced at lower temperatures as compared with (U{sub 0.7}Pu{sub 0.3})O{sub 1.99}. Thermal expansion was observed to be slightly increased with decreasing O/M ratio. (authors)

  13. Melt processing of the Bi[sub 2]Sr[sub 2]CaCu[sub 2]O[sub y] superconductor in oxygen and argon atmospheres

    SciTech Connect (OSTI)

    Holesinger, T.G.; Miller, D.J. ); Chumbley, L.S. )

    1992-08-01

    Solidification and subsequent annealing of Bi[sub 2]Sr[sub 2]CaCu[sub 2]O[sub y] (2212) in oxygen and argon atmospheres were investigated in order to identify alternative processing routes for controlling microstructures and superconducting properties. In addition to 2212, several other phases formed on cooling in O[sub 2] and did not disappear upon subsequent annealing. Crystallization in Ar resulted in a divorced eutetic structure of Bi[sub 2]Sr[sub 3-x]Ca[sub x]O[sub y] and Cu[sub 2]O/CuO. The superconductor was formed on subsequent anneals. Samples melted in Ar and then annealed generally possessed a more uniform microstructure compared with samples that were melted in oxygen and annealed. Compositional measurements of the 2212 phase suggest that CaO segregation in the melt may be minimized with an overall composition such as Bi[sub 2.15]Sr[sub 2]Ca[sub 0.85]Cu[sub 2]O[sub y].

  14. Melt processing of the Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub y} superconductor in oxygen and argon atmospheres

    SciTech Connect (OSTI)

    Holesinger, T.G.; Miller, D.J.; Chumbley, L.S.

    1992-08-01

    Solidification and subsequent annealing of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub y} (2212) in oxygen and argon atmospheres were investigated in order to identify alternative processing routes for controlling microstructures and superconducting properties. In addition to 2212, several other phases formed on cooling in O{sub 2} and did not disappear upon subsequent annealing. Crystallization in Ar resulted in a divorced eutetic structure of Bi{sub 2}Sr{sub 3-x}Ca{sub x}O{sub y} and Cu{sub 2}O/CuO. The superconductor was formed on subsequent anneals. Samples melted in Ar and then annealed generally possessed a more uniform microstructure compared with samples that were melted in oxygen and annealed. Compositional measurements of the 2212 phase suggest that CaO segregation in the melt may be minimized with an overall composition such as Bi{sub 2.15}Sr{sub 2}Ca{sub 0.85}Cu{sub 2}O{sub y}.

  15. Facile synthesis of MoS{sub 2} and Mo{sub x}W{sub 1-x}S{sub 2} triangular monolayers

    SciTech Connect (OSTI)

    Lin, Zhong; Thee, Michael T.; Elías, Ana Laura; Feng, Simin; Fujisawa, Kazunori; Perea-López, Néstor; Carozo, Victor [Department of Physics and Center for 2Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Zhou, Chanjing [Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Terrones, Humberto [Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 122180 (United States); Terrones, Mauricio, E-mail: mut11@psu.edu [Department of Physics and Center for 2Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

    2014-09-01

    Single- and few-layered transition metal dichalcogenides, such as MoS{sub 2} and WS{sub 2}, are emerging two-dimensional materials exhibiting numerous and unusual physico-chemical properties that could be advantageous in the fabrication of unprecedented optoelectronic devices. Here we report a novel and alternative route to synthesize triangular monocrystals of MoS{sub 2} and Mo{sub x}W{sub 1-x}S{sub 2} by annealing MoS{sub 2} and MoS{sub 2}/WO{sub 3} precursors, respectively, in the presence of sulfur vapor. In particular, the Mo{sub x}W{sub 1-x}S{sub 2} triangular monolayers show gradual concentration profiles of W and Mo whereby Mo concentrates in the islands’ center and W is more abundant on the outskirts of the triangular monocrystals. These observations were confirmed by atomic force microscopy, and high-resolution transmission electron microscopy, as well as Raman and photoluminescence spectroscopy. The presence of tunable PL signals depending on the Mo{sub x}W{sub 1-x}S{sub 2} stoichiometries in 2D monocrystals opens up a wide range of applications in electronics and optoelectronics.

  16. A Fission Gas Release Model for High-Burnup LWR ThO{sub 2}-UO{sub 2} Fuel

    SciTech Connect (OSTI)

    Long, Yun; Yi Yuan; Kazimi, Mujid S.; Ballinger, Ronald G.; Pilat, Edward E.

    2002-06-15

    Fission gas release in thoria-urania fuel has been investigated by creating a specially modified FRAPCON-3 code. Because of the reduced buildup of {sup 239}Pu and a flatter distribution of {sup 233}U, the new model THUPS (Thoria-Urania Power Shape) was developed to calculate the radial power distribution, including the effects of both plutonium and {sup 233}U. Additionally, a new porosity model for the rim region was introduced at high burnup. The mechanisms of fission gas release in ThO{sub 2}-UO{sub 2} fuel are expected to be essentially similar to those of UO{sub 2} fuel; therefore, the general formulations of the existing fission gas release models in FRAPCON-3 were retained. However, the gas diffusion coefficient was adjusted to a lower level to account for the smaller observed release fraction in the thoria-based fuel. To model the accelerated fission gas release at high burnup properly, a new athermal fission gas release model was introduced. The modified version of FRAPCON-3 was calibrated using the measured fission gas release data from the light water breeder reactor. Using the new model to calculate the gas release in typical pressurized water reactor hot pins gives data that indicate that the ThO{sub 2}-UO{sub 2} fuel will have considerably lower fission gas release above a burnup of 50 MWd/kg HM.

  17. Magnetic, dielectric, and magnetoelectric properties in Sr{sub 2}CoGe{sub 2}O{sub 7}

    SciTech Connect (OSTI)

    Song, Y. Q.; Li, Q.; Zhou, W. P.; Cao, Q. Q.; Wang, D. H. Du, Y. W.; Zhang, Z. M.; Xu, Q. Y.

    2015-05-07

    We investigate the magnetoelectric effect in Sr{sub 2}CoGe{sub 2}O{sub 7}, which has a two-dimensional magnetic interaction between Co ions in the ab plane. This compound shows a weak magnetism and field-induced magnetic transition below the temperature of 7?K. It does not exhibit electric polarization under zero magnetic field. However, by applying an external magnetic field, the electric polarization is induced around its Néel temperature and increases with increasing magnetic field. The induced electric polarization in Sr{sub 2}CoGe{sub 2}O{sub 7} is almost two orders of magnitude smaller than that of Ba{sub 2}CoGe{sub 2}O{sub 7}. This result suggests that the different ionic radius of the strontium and the barium anion plays a key role in determining the property of electric polarization. The origins of electric polarization and magnetoelectric effect are discussed.

  18. Quantum paraelectric glass state in SrCu{sub 3}Ti{sub 4}O{sub 12}

    SciTech Connect (OSTI)

    Kumar, Jitender; Choudhary, Ram Janay; Awasthi, A. M., E-mail: amawasthi@csr.res.in [UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452001 (India)

    2014-06-30

    Magnetic and dielectric studies of SrCu{sub 3}Ti{sub 4}O{sub 12} carried out over 5–300?K confirm antiferromagnetic (AFM) ordering of Cu-spins at T{sub N}?=?23?K. Dielectric constant ?? measured across 1?Hz-1 MHz signifies quantum paraelectric character, Barrett-fittable almost down to T{sub N}. Competition of athermal fluctuations and the literature-reported magneto-phonon-softening near T{sub N} manifest a quantum paraelectric glass (QPG) state. Emergent AFM-field tunes the otherwise quantum ordering (at absolute-zero) of the dipoles to finite-temperature kinetic glass transition; spectral dispersion of dielectric constant was unambiguously manifested and characterized. Vogel-Fulcher glass-kinetics parameterization sets the almost relaxation-free QPG state in SrCu{sub 3}Ti{sub 4}O{sub 12} apart from an emergent scaling-class, to which typical ferroelectric relaxors belong.

  19. High-temperature phase transformation and topochemical nature in ferroelastic (NH{sub 4}){sub 2}SO{sub 4}

    SciTech Connect (OSTI)

    Lee, Kwang-Sei; Oh, In-Hwan; Ko, Jae-Hyeon

    2014-04-01

    The electrical conductivity of ferroelastic ammonium sulfate (NH{sub 4}){sub 2}SO{sub 4} revealed an anomaly at around 130 °C (=403 K, T{sub P}) on heating with large and irreversible thermal hysteresis through thermal cycle. Ferroelastic domain walls and surface morphology of (NH{sub 4}){sub 2}SO{sub 4} were investigated by hot-stage polarizing microscopy. Structural phase transition from an orthorhombic ferroelastic phase to a hexagonal paraelastic phase was not identified at T{sub P} upon heating. On further heating above T{sub P}, microscopic spots appeared and grew on the crystal surface, suggesting that the high-temperature anomaly at T{sub P} was an indication of an onset of thermal decomposition controlled by topochemical factors. The increase of electrical conductivity above T{sub P} was attributed to proton migration. - Graphical abstract: Surface morphology of the (100) face of (NH{sub 4}){sub 2}SO{sub 4} on heating, showing chemical reaction at the surface. - Highlights: • We investigate the high-temperature phase transformation of ammonium sulfate. • The increasing conductivity upon heating is attributed to proton migration. • Structural phase transition from orthorhombic to hexagonal phase is not confirmed. • High-temperature anomaly is related to an onset of thermal decomposition. • The nature of the high-temperature anomaly is topochemical controlled by defects.

  20. Scintillator having a MgAI.sub.2O.sub.4 host lattice

    DOE Patents [OSTI]

    Chen, Ching-Fong (Los Alamos, NM)

    2011-12-20

    A scintillator having a host lattice of MgAl.sub.2O.sub.4 was prepared by hot pressing under a vacuum environment a powder mixture of MgAl.sub.2O.sub.4, CeO.sub.2, and LiF.

  1. Reduced dimension rovibrational variational calculations of the S{sub 1} state of C{sub 2}H{sub 2}. I. Methodology and implementation

    SciTech Connect (OSTI)

    Changala, P. Bryan

    2014-01-14

    The bending and torsional degrees of freedom in S{sub 1} acetylene, C{sub 2}H{sub 2}, are subject to strong vibrational resonances and rovibrational interactions, which create complex vibrational polyad structures even at low energy. As the internal energy approaches that of the barrier to cis-trans isomerization, these energy level patterns undergo further large-scale reorganization that cannot be satisfactorily treated by traditional models tied to local minima of the potential energy surface for nuclear motion. Experimental spectra in the region near the cis-trans transition state have revealed these complicated new patterns. In order to understand near-barrier spectroscopic observations and to predict the detailed effects of cis-trans isomerization on the rovibrational energy level structure, we have performed reduced dimension rovibrational variational calculations of the S{sub 1} state. In this paper, we present the methodological details, several of which require special care. Our calculation uses a high accuracy ab initio potential surface and a fully symmetrized extended complete nuclear permutation inversion group theoretical treatment of a multivalued internal coordinate system that is appropriate for large amplitude bending and torsional motions. We also discuss the details of the rovibrational basis functions and their symmetrization, as well as the use of a constrained reduced dimension rovibrational kinetic energy operator.

  2. NORTHWEST REGIONAL TECHNOLOGY CENTER

    E-Print Network [OSTI]

    NORTHWEST REGIONAL TECHNOLOGY CENTER for Homeland Security Northwest Regional Technology Center May 2015 | 1 AROUND THE REGION IN HOMELAND SECURITY The Northwest Regional Technology Center (NWRTC.S. Army Cyber Command; and Michael Echols, Director, Cyber Joint Program Management Office National

  3. Conservation Regional ConservationRegional Conservation

    E-Print Network [OSTI]

    Northwest Power and Conservation Council Regional ConservationRegional Conservation Update:Update?"" #12;slide 3 Northwest Power and Conservation Council PNW Energy Efficiency AchievementsPNW Energy Since 1978 Utility & BPASince 1978 Utility & BPA Programs, Energy Codes &Programs, Energy Codes

  4. SUB-POPULATION BRAIN ATLASES

    E-Print Network [OSTI]

    Thompson, Paul

    SUB-POPULATION BRAIN ATLASES Paul Thompson PhD, Michael S. Mega MD PhD, and Arthur W. Toga PhD Laboratory of Neuro Imaging, Brain Mapping Division and Alzheimer's Disease Center Dept. of Neurology, UCLA School of Medicine, Los Angeles, CA 90095-1769 A Chapter in: Brain Mapping: The Methods (2nd Edition

  5. Method of producing superconducting fibers of YBa[sub 2]Cu[sub 3]O[sub x

    DOE Patents [OSTI]

    Schwartzkopf, L.A.; Ostenson, J.E.; Finnemore, D.K.

    1990-11-13

    Fibers of YBa[sub 2]Cu[sub 3]O[sub x] have been produce by pendant drop melt extraction. This technique involves the end of a rod of YBa[sub 2]Cu[sub 3]O[sub x] melted with a hydrogen-oxygen torch, followed by lowering onto the edge of a spinning wheel. The fibers are up to 10 cm in length with the usual lateral dimensions, ranging from 20 [mu]m to 125 [mu]m. The fibers require a heat treatment to make them superconducting.

  6. Thickness dependence of magnetoelectric response for composites of Pb(Zr{sub 0.52}Ti{sub 0.48})O{sub 3} films on CoFe{sub 2}O{sub 4} ceramic substrates

    SciTech Connect (OSTI)

    Wang, Jing Zhu, Kongjun; Wu, Xia; Deng, Chaoyong; Peng, Renci; Wang, Jianjun

    2014-08-15

    Using chemical solution spin-coating we grew Pb(Zr{sub 0.52}Ti{sub 0.48})O{sub 3} films of different thicknesses on highly dense CoFe{sub 2}O{sub 4} ceramics. X-ray diffraction revealed no other phases except Pb(Zr{sub 0.52}Ti{sub 0.48})O{sub 3} and CoFe{sub 2}O{sub 4}. In many of these samples we observed typical ferroelectric hysteresis loops, butterfly-shaped piezoelectric strains, and the magnetic-field-dependent magnetostriction. These behaviors caused appreciable magnetoelectric responses based on magnetic-mechanical-electric coupling. Our results indicated that the thickness of the Pb(Zr{sub 0.52}Ti{sub 0.48})O{sub 3} film was important in obtaining strong magnetoelectric coupling.

  7. Effect of SO<sub>2sub> on oxidation of metallic materials in CO<sub>2sub>/H>2sub>O-rich gases relevant to oxyfuel environments

    SciTech Connect (OSTI)

    Huczkowski, P.; Olszewski, T.; Schiek, M.; Lutz, B.; Holcomb, G.; Shemet, V.; Meier, G. H.; Singheiser, L.; Quadakkers, W. J.

    2012-09-19

    This report is a description of research performed by the Jülich Research Centre. Their conclusions outline the effects of SO<sub>2sub> additions on oxide formations and the interaction of other gases in oxvyfuel environments.

  8. Band alignment and electrical properties of Al{sub 2}O{sub 3}/?-Ga{sub 2}O{sub 3} heterojunctions

    SciTech Connect (OSTI)

    Kamimura, Takafumi Hoi Wong, Man; Krishnamurthy, Daivasigamani; Higashiwaki, Masataka; Sasaki, Kohei; Kuramata, Akito; Yamakoshi, Shigenobu; Masui, Takekazu

    2014-05-12

    The band alignment of Al{sub 2}O{sub 3}/n-Ga{sub 2}O{sub 3} was investigated by x-ray photoelectron spectroscopy (XPS). With a band gap of 6.8?±?0.2?eV measured for Al{sub 2}O{sub 3}, the conduction and valence band offsets at the interface were estimated to be 1.5?±?0.2?eV and 0.7?±?0.2?eV, respectively. The conduction band offset was also obtained from tunneling current in Al{sub 2}O{sub 3}/n-Ga{sub 2}O{sub 3} (2{sup ¯}01) metal-oxide-semiconductor (MOS) diodes using the Fowler-Nordheim model. The electrically extracted value was in good agreement with the XPS data. Furthermore, the MOS diodes exhibited small capacitance-voltage hysteresis loops, indicating the successful engineering of a high-quality Al{sub 2}O{sub 3}/Ga{sub 2}O{sub 3} interface.

  9. Location of trivalent lanthanide dopant energy levels in (Lu{sub 0.5}Gd{sub 0.5}){sub 2}O{sub 3}

    SciTech Connect (OSTI)

    Retot, H.; Viana, B.; Bessiere, A.; Galtayries, A.

    2011-06-15

    The location of Ln{sup 3+} dopant energy levels relative to bands in (Lu{sub 0.5}Gd{sub 0.5}){sub 2}O{sub 3} was studied. A several-steps analysis of XPS measurements on heavy lanthanides sesquioxides Ln{sub 2}O{sub 3} (Ln = Gd, Tb, Dy, Er, Tm, Yb, Lu) and on Sc{sub 2}O{sub 3} and Y{sub 2}O{sub 3} reference materials were used to locate Ln{sup 3+} dopant ground state relative to the top of the valence band in (Lu{sub 0.5}Gd{sub 0.5}){sub 2}O{sub 3} within an error bar of {+-}0.4 eV. The agreement between XPS data and model was found improved relative to previous studies. When compared to XPS analysis, prediction based on optical absorption shows a slight underestimation attributed to the lack of precision in Ce{sup 4+} charge transfer band measurement.

  10. Synthesis and structural characterization of the ternary Zintl phases AE{sub 3}Al{sub 2}Pn{sub 4} and AE{sub 3}Ga{sub 2}Pn{sub 4} (AE=Ca, Sr, Ba, Eu; Pn=P, As)

    SciTech Connect (OSTI)

    He, Hua; Tyson, Chauntae; Saito, Maia [Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716 (United States); Bobev, Svilen, E-mail: bobev@udel.edu [Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716 (United States)

    2012-04-15

    Ten new ternary phosphides and arsenides with empirical formulae AE{sub 3}Al{sub 2}Pn{sub 4} and AE{sub 3}Ga{sub 2}Pn{sub 4} (AE=Ca, Sr, Ba, Eu; Pn=P, As) have been synthesized using molten Ga, Al, and Pb fluxes. They have been structurally characterized by single-crystal and powder X-ray diffraction to form with two different structures-Ca{sub 3}Al{sub 2}P{sub 4}, Sr{sub 3}Al{sub 2}As{sub 4}, Eu{sub 3}Al{sub 2}P{sub 4}, Eu{sub 3}Al{sub 2}As{sub 4}, Ca{sub 3}Ga{sub 2}P{sub 4}, Sr{sub 3}Ga{sub 2}P{sub 4}, Sr{sub 3}Ga{sub 2}As{sub 4}, and Eu{sub 3}Ga{sub 2}As{sub 4} crystallize with the Ca{sub 3}Al{sub 2}As{sub 4} structure type (space group C2/c, Z=4); Ba{sub 3}Al{sub 2}P{sub 4} and Ba{sub 3}Al{sub 2}As{sub 4} adopt the Na{sub 3}Fe{sub 2}S{sub 4} structure type (space group Pnma, Z=4). The polyanions in both structures are made up of TrPn{sub 4} tetrahedra, which share common corners and edges to form {sup 2}{sub {infinity}}[TrPn{sub 2}]{sub 3-} layers in the phases with the Ca{sub 3}Al{sub 2}As{sub 4} structure, and {sup 1}{sub {infinity}}[TrPn{sub 2}]{sub 3-} chains in Ba{sub 3}Al{sub 2}P{sub 4} and Ba{sub 3}Al{sub 2}As{sub 4} with the Na{sub 3}Fe{sub 2}S{sub 4} structure type. The valence electron count for all of these compounds follows the Zintl-Klemm rules. Electronic band structure calculations confirm them to be semiconductors. - Graphical abstract: AE{sub 3}Al{sub 2}Pn{sub 4} and AE{sub 3}Ga{sub 2}Pn{sub 4} (AE=Ca, Sr, Ba, Eu; Pn=P, As) crystallize in two different structures-Ca{sub 3}Al{sub 2}P{sub 4}, Sr{sub 3}Al{sub 2}As{sub 4}, Eu{sub 3}Al{sub 2}P{sub 4}, Eu{sub 3}Al{sub 2}As{sub 4}, Ca{sub 3}Ga{sub 2}P{sub 4}, Sr{sub 3}Ga{sub 2}P{sub 4}, Sr{sub 3}Ga{sub 2}As{sub 4}, and Eu{sub 3}Ga{sub 2}As{sub 4}, are isotypic with the previously reported Ca{sub 3}Al{sub 2}As{sub 4} (space group C2/c (No. 15)), while Ba{sub 3}Al{sub 2}P{sub 4} and Ba{sub 3}Al{sub 2}As{sub 4} adopt a different structure known for Na{sub 3}Fe{sub 2}S{sub 4} (space group Pnma (No. 62). The polyanions in both structures are made up of TrPn{sub 4} tetrahedra, which by sharing common corners and edges, form {sup 2}{sub {infinity}}[TrPn{sub 2}]{sub 3-}layers in the former and {sup 1}{sub {infinity}}[TrPn{sub 2}]{sub 3-} chains in Ba{sub 3}Al{sub 2}P{sub 4} and Ba{sub 3}Al{sub 2}As{sub 4}. Highlights: Black-Right-Pointing-Pointer AE{sub 3}Ga{sub 2}Pn{sub 4} (AE=Ca, Sr, Ba, Eu; Pn=P, As) are new ternary pnictides. Black-Right-Pointing-Pointer Ba{sub 3}Al{sub 2}P{sub 4} and Ba{sub 3}Al{sub 2}As{sub 4} adopt the Na{sub 3}Fe{sub 2}S{sub 4} structure type. Black-Right-Pointing-Pointer The Sr- and Ca-compounds crystallize with the Ca{sub 3}Al{sub 2}As{sub 4} structure type. Black-Right-Pointing-Pointer The valence electron count for all title compounds follows the Zintl-Klemm rules.

  11. Seismic Modelling for the Sub-Basalt Imaging Problem Including an Analysis and Development of the Boundary Element Method 

    E-Print Network [OSTI]

    Dobson, Andrew

    The north-east Atlantic margin (NEAM) is important for hydrocarbon exploration because of the growing evidence of hydrocarbon reserves in the region. However, seismic exploration of the sub-surface is hampered by large ...

  12. Infrared-optical spectroscopy of transparent conducting perovskite (La,Ba)SnO{sub 3} thin films

    SciTech Connect (OSTI)

    Seo, Dongmin; Yu, Kwangnam; Jun Chang, Young; Choi, E. J.; Sohn, Egon; Hoon Kim, Kee

    2014-01-13

    We have performed optical transmission, reflection, spectroscopic ellipsometry, and Hall effect measurements on the electron-doped La{sub x}Ba{sub 1–x}SnO{sub 3} (x?=?0.04) transparent thin films. From the infrared Drude response and plasma frequency analysis we determine the effective mass of the conducting electron m*?=?0.35m{sub 0}. In the visible-UV region the optical band gap shifts to high energy in (La,Ba)SnO{sub 3} by 0.18?eV compared with undoped BaSnO{sub 3} which, in the context of the Burstein-Moss analysis, is consistent with the infrared-m*. m* of BaSnO{sub 3} is compared with other existing transparent conducting oxides (TCO), and implication on search for high-mobility TCO compounds is discussed.

  13. Crystal structures and luminescence properties of novel compounds K{sub 4}M{sub 2}[Al{sub 2}Si{sub 8}O{sub 24}] (M = Ce, Gd)

    SciTech Connect (OSTI)

    Aksenov, S. M., E-mail: aks.crys@gmail.com [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Rassulov, V. A. [Russian Academy of Sciences, Fedorovsky All-Russian Research Institute of Mineral Resources (Russian Federation)] [Russian Academy of Sciences, Fedorovsky All-Russian Research Institute of Mineral Resources (Russian Federation); Rastsvetaeva, R. K. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)] [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Taroev, V. K. [Russian Academy of Sciences, Institute of Geochemistry, Siberian Branch (Russian Federation)] [Russian Academy of Sciences, Institute of Geochemistry, Siberian Branch (Russian Federation)

    2013-11-15

    Two novel potassium rare earth silicates, obtained by hydrothermal synthesis, have been investigated by X-ray diffraction and described by the general formula K{sub 4}M{sub 2}[Al{sub 2}Si{sub 8}O{sub 24}] (M = Ce, Gd). The parameters of the monoclinic K{sub 4}Ce{sub 2}[Al{sub 2}Si{sub 8}O{sub 24}] and K{sub 4}Gd{sub 2}[Al{sub 2}Si{sub 8}O{sub 24}] cells are, respectively, as follows: a = 26.867(1), 26.6520(2) A; b = 7.4150(2), 7.2854(1) A; c = 14.910(1), 14.8182(1) A; {beta} = 123.52(1) Degree-Sign , 123.46(1) Degree-Sign ; and sp. gr. P2{sub 1}/n. The structures are solved by the charge flipping method and refined in the anisotropic approximation of thermal vibrations for atoms to R = 5.2 and 2.5%, respectively. The compounds under study are crystallized into a new structural type, which is based on two-level [Al{sub 2}Si{sub 8}O{sub 24}] layers, combined into a three-dimensional framework by columns of edge-sharing seven-vertex REE polyhedra. Potassium atoms are located in the framework channels. The spectral luminescence characteristics are determined. The luminescence bands are typical of Gd{sup 3+} and Ce{sup 3+} ions. Upon excitation by light with {lambda}{sub exc} = 246 nm, a band due to the {sup 2}D {yields} {sup 8}F{sub 5/2} transition with {lambda}{sub max} = 430 nm is observed in the spectrum of K{sub 4}Ce{sub 2}[Al{sub 2}Si{sub 8}O{sub 24}] and a band related to the {sup 6}P{sub 7/2} {yields} {sup 8}S{sub 7/2} transition with {lambda}{sub max} = 311 nm is observed in the spectrum of K{sub 4}Gd{sub 2}[Al{sub 2}Si{sub 8}O{sub 24}].

  14. Solid-state reaction preparation and photoluminescence properties of Na{sub 2}Ba{sub 6}(Si{sub 2}O{sub 7})(SiO{sub 4}){sub 2}:Eu{sup 2+} phosphors

    SciTech Connect (OSTI)

    Shi, Pinglu; Xia, Zhiguo, E-mail: xiazg@cugb.edu.cn

    2014-01-01

    Graphical abstract: - Highlights: • Green-emitting phosphor powder Na{sub 2}Ba{sub 6}(Si{sub 2}O{sub 7})(SiO{sub 4}){sub 2}:Eu{sup 2+} was synthesized. • Two different emission centers occupied by Eu{sup 2+} were investigated. • The concentration quenching mechanism was studied. - Abstract: A kind of novel green-emitting phosphor Na{sub 2}Ba{sub 6}(Si{sub 2}O{sub 7})(SiO{sub 4}){sub 2}:Eu{sup 2+} was synthesized by a solid-state reaction. The phase formation of as-prepared sample was investigated by X-ray powder diffraction. The photoluminescence emission (PL) and excitation (PLE) spectra results indicated that the phosphor could be efficiently excited by ultraviolet (UV) light from 240 to 400 nm, and presented a broad green emission band with two-band profile suggesting two different emission centers occupied by Eu{sup 2+}. The critical quenching concentration of Eu{sup 2+} was determined to be 0.01 mol and the concentration quenching mechanism was also investigated.

  15. Dispersion states and acid properties of SiO{sub 2}-supported Nb{sub 2}O{sub 5}

    SciTech Connect (OSTI)

    He, Jie; Li, Qing-Jie; Fan, Yi-Ning

    2013-06-15

    Nb{sub 2}O{sub 5}/SiO{sub 2} samples were prepared by the incipient-wetness impregnation method using niobium oxalate aqueous solution. The microstructure and dispersion process of the niobia species supported on SiO{sub 2} were characterized by means of power X-ray diffraction (XRD), laser Raman spectroscopy (LRS), and UV–vis diffuse reflectance spectroscopy (UV–vis DRS). The acid properties were investigated by the method of Hammett indicator and Pyridine adsorption infrared (Py-IR) spectroscopy. The results showed that the dispersion process of Nb{sub 2}O{sub 5} was performed by consuming surface hydroxyl groups of the amorphous SiO{sub 2} support. The aggregation of niobia species led to the formation of microcrystalline particles, so that there was no a clear monolayer dispersion capacity for Nb{sub 2}O{sub 5} supported on amorphous SiO{sub 2}. Furthermore, the catalytic activities of the as-prepared samples were evaluated by the condensation reaction of iso-butene (IB) and iso-butyraldehyde (IBA) to form 2,5-dimethyl-2,4-hexadiene (DMHD). The catalytic activities of the as-prepared samples for the condensation and their acid properties were strongly affected by the dispersion states. - Graphical abstract: The acid amount and strength of Nb{sub 2}O{sub 5}/SiO{sub 2} samples varied with the increase of Nb{sub 2}O{sub 5} loading. The catalytic activities of the as-prepared samples for the condensation and their acid properties were strongly affected by the dispersion states. - Highlights: • The dispersed process of Nb{sub 2}O{sub 5} was completed by consuming surface hydroxyl groups of SiO{sub 2}. • XRD quantitative phase analysis is not applicable for oxides dispersing on amorphous support. • The catalytic activity of Nb{sub 2}O{sub 5}/SiO{sub 2} is closely related to the dispersion state of SiO{sub 2}.

  16. Structural and magnetic properties of triethylene glycol stabilized Zn{sub x}Co{sub 1?x}Fe{sub 2}O{sub 4} nanoparticles

    SciTech Connect (OSTI)

    Sozeri, H.; Durmus, Z.; Baykal, A.

    2012-09-15

    Highlights: ? Monodispersed TREG stabilized Zn{sub x}Co{sub 1?x}Fe{sub 2}O{sub 4} NP's were prepared via hydrothermal method. ? Zn{sub x0.6}Co{sub 0.4}Fe{sub 2}O{sub 4} NP's has superparamagnetic behavior like absence of saturation at high fields. ? The lattice parameter (a{sub o}) increases linearly with the addition of Zn and follows Vegard's law. -- Abstract: Zn substituted cobalt ferrite nanoparticles having formula of Zn{sub x}Co{sub 1?x}Fe{sub 2}O{sub 4} (x = 0.0–1.0) were prepared by hydrothermal technique. In this process, triethylene glycol was used as a solvent and surfactant, anhydrous sodium hydroxide was used as an alkalinity additive. Investigation of the structural, morphological and thermal properties were carried out using X-ray diffraction (XRD), infrared spectroscopy (FT-IR), transmission electron spectroscopy (TEM) and thermal analysis (TGA) respectively. The X-ray diffraction study reveals that the lattice constant of cobalt ferrite increases with the increase of Zn content. Magnetization measurements showed that as zinc concentration increases saturation magnetization initially stays constant and then decreases monotically. Samples having high zinc concentration (x ? 0.6) have superparamagnetic behavior like absence of saturation at high fields, low saturation magnetization values and immeasurable coercivity. These features were explained by surface spin disorder and canted spins.

  17. Self-interacting scalar dark matter with local Z{sub 3} symmetry

    SciTech Connect (OSTI)

    Ko, P.; Tang, Yong E-mail: ytang@kias.re.kr

    2014-05-01

    We construct a self-interacting scalar dark matter (DM) model with local discrete Z{sub 3} symmetry that stabilizes a weak scale scalar dark matter X. The model assumes a hidden sector with a local U(1){sub X} dark gauge symmetry, which is broken spontaneously into Z{sub 3} subgroup by nonzero VEV of dark Higgs field ?{sub X} ((?{sub X})?0). Compared with global Z{sub 3} DM models, the local Z{sub 3} model has two new extra fields: a dark gauge field Z{sup '} and a dark Higgs field ? (a remnant of the U(1){sub X} breaking). After imposing various constraints including the upper bounds on the spin-independent direct detection cross section and thermal relic density, we find that the scalar DM with mass less than 125 GeV is allowed in the local Z{sub 3} model, in contrary to the global Z{sub 3} model. This is due to new channels in the DM pair annihilations open into Z{sup '} and ? in the local Z{sub 3} model. Most parts of the newly open DM mass region can be probed by XENON1T and other similar future experiments. Also if ? is light enough (a few MeV ?sub ?}?< O(100) MeV), it can generate a right size of DM self-interaction and explain the astrophysical small scale structure anomalies. This would lead to exotic decays of Higgs boson into a pair of dark Higgs bosons, which could be tested at LHC and ILC.

  18. Strain induced Z{sub 2} topological insulating state of ?-As{sub 2}Te{sub 3}

    SciTech Connect (OSTI)

    Pal, Koushik; Waghmare, Umesh V.

    2014-08-11

    Topological insulators are non-trivial quantum states of matter which exhibit a gap in the electronic structure of their bulk form, but a gapless metallic electronic spectrum at the surface. Here, we predict a uniaxial strain induced electronic topological transition (ETT) from a band to topological insulating state in the rhombohedral phase (space group: R3{sup ¯}m) of As{sub 2}Te{sub 3} (?-As{sub 2}Te{sub 3}) through first-principles calculations including spin-orbit coupling within density functional theory. The ETT in ?-As{sub 2}Te{sub 3} is shown to occur at the uniaxial strain ?{sub zz}?=??0.05 (?{sub zz}?=?1.77?GPa), passing through a Weyl metallic state with a single Dirac cone in its electronic structure at the ? point. We demonstrate the ETT through band inversion and reversal of parity of the top of the valence and bottom of the conduction bands leading to change in the ?{sub 2} topological invariant ?{sub 0} from 0 to 1 across the transition. Based on its electronic structure and phonon dispersion, we propose ultra-thin films of As{sub 2}Te{sub 3} to be promising for use in ultra-thin stress sensors, charge pumps, and thermoelectrics.

  19. SiO{sub 2}/SiC structures annealed in D{sub 2}{sup 18}O: Compositional and electrical effects

    SciTech Connect (OSTI)

    Pitthan, E. Corrêa, S. A.; Soares, G. V.; Boudinov, H. I.; Stedile, F. C.

    2014-03-17

    Effects of water vapor annealing on SiO{sub 2}/4H-SiC structures formed following different routes were investigated using water isotopically enriched in {sup 18}O and {sup 2}H (D). Isotopic exchange between oxygen from the water vapor and oxygen from SiO{sub 2} films deposited on 4H-SiC was observed in the whole depth of the films, differently from the behavior of SiO{sub 2} films thermally grown on 4H-SiC. The highest amount of D was obtained in the sample with the highest negative fixed charge concentration, suggesting that the D incorporation occurs in defects in the structure that exist prior to the annealing. As a consequence of the water annealing, a significant reduction in the negative effective charge in metal-oxide-semiconductor capacitors and the removal of the SiO{sub 2}/SiC interfacial region was observed, attributed to the reduction of the amount of SiO{sub x}C{sub y} compounds in the interfacial region.

  20. Regional Research Collaborations

    E-Print Network [OSTI]

    Regional Research Collaborations Merrill Series on The Research Mission of Public Universities at Birmingham Regional Neuroscience Research Collaboration: The Alabama Experience Panel 1: Research ........................................................................................................5 Vice Chancellor for Research, University of Kansas Medical Center Evolution of Reproductive

  1. Magnetic behavior of LaMn{sub 2}(Si{sub (1?x)}Ge{sub x}){sub 2} compounds characterized by magnetic hyperfine field measurements

    SciTech Connect (OSTI)

    Bosch-Santos, B., E-mail: brianna@usp.br; Carbonari, A. W.; Cabrera-Pasca, G. A.; Saxena, R. N. [Instituto de Pesquisas Energéticas e Nucleares, University of São Paulo, 05508-000 São Paulo (Brazil)

    2014-05-07

    The temperature dependence of the magnetic hyperfine field (B{sub hf}) at Mn atom sites was measured in LaMn{sub 2}(Si{sub (1?x)}Ge{sub x}){sub 2}, with 0???x???1, compounds with perturbed ??? angular correlation spectroscopy using {sup 111}In({sup 111}Cd) as probe nuclei in the temperature range from 20?K to 480?K. The results show a transition from antiferromagnetic to ferromagnetic ordering for all studied compounds when Ge gradually replaces Si and allowed an accurate determination of the Néel temperature (T{sub N}) for each compound. It was observed that T{sub N} decreases when Ge concentration increases. Conversely, the Curie temperature increases with increase of Ge concentration. This remarkable change in the behavior of the transition temperatures is discussed in terms of the Mn-Mn distance and ascribed to a change in the exchange constant J{sub ex}.

  2. Compact Li-doped Gd{sub 2}Ti{sub 2}O{sub 7} prepared with LiO{sub 0.5} self-flux

    SciTech Connect (OSTI)

    Wen, L.C.; Hsieh, H.Y.; Chang, S.C.; Lin, M.Y.; Lee, Y.H.; Su, W.P. [Department of Chemistry, Tamkang University, New Taipei City 25137, Taiwan (China); Kao, H.-C.I., E-mail: kaohci@mail.tku.edu.tw [Department of Chemistry, Tamkang University, New Taipei City 25137, Taiwan (China); Sheu, H.S.; Jang, L.Y. [National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan (China); Lee, M.C.; Lee, Y.S. [Institute of Nuclear Energy Research, Atomic Energy Council, Longtan 32546, Taiwan (China)

    2014-02-01

    Graphical abstract: Left figure is the unit cell a-axis of the GLT-2L (?), GLT (?) and GT (?) as a function of x. Both of the GLT-2L and GLT have the same results so that they have the same chemical formula, (Gd{sub 2?x}Li{sub x})Ti{sub 2}O{sub 7?x}, in which GT has a formula of Gd{sub 2?x}Ti{sub 2}O{sub 7?x}. Relative densities are shown in the right figure. GLT-2L (?) has higher values than GLT (?). 2x moles of LiO{sub 0.5} were added as a self-flux to prepare GLT-2L at 1250 °C, which was about 300 °C lowered than required without the co-existence of the flux and Li ion substitution. - Highlights: • A new series of compounds with a formula as (Gd{sub 2?x}Li{sub x})Ti{sub 2}O{sub 7?x} was synthesized. • Each GLT-2L sample contains (Gd{sub 2?x}Li{sub x})Ti{sub 2}O{sub 7?x} and 2x moles of LiO{sub 0.5} self-flux. • 1250 °C was used to prepare the GLT-2L samples; 300 °C lower than required. • Electrical conductivity of the GLT-2L is not affected by the presence of the flux. • Average valence of the Ti ions is slightly less than 4. - Abstract: A series of (Gd{sub 2?x}Li{sub x})Ti{sub 2}O{sub 7?x} with x = 0.040–0.110 was first reported. Parent compound with 2x moles of LiO{sub 0.5} self-flux was prepared at 1250 °C and abbreviated as GLT-2L. Relative density of all the samples is higher than 92%. By the addition of flux and Li ions substitution, preparation temperature is lowered for more than 300 °C. Comparing the unit cell a-axis, GLT with a formula as (Gd{sub 2?x}Li{sub x})Ti{sub 2}O{sub 7?x} without flux addition has exactly the same as the GLT-2L with the same x. By the addition of flux, materials become more compact and grains grow bigger for the GLT-2L than the corresponding GLT samples. Electrical conductivity of a GLT-2L with x = 0.110 at 700 °C is 3 times larger than the measurements done by other research groups in the Gd{sub 2}Ti{sub 2}O{sub 7}. In order to demonstrate the successful substitution of the Li ion into the Gd site, a series of GT samples was prepared with a formula of Gd{sub 2?x}Ti{sub 2}O{sub 7?1.5x}. With the same amount of x, every GLT samples have a longer unit cell a-axis than that of the GT. The difference is caused by the substitution of the Li ion into the Gd site. Valence of the Ti atoms of the GLT-2L samples is slightly less than 4 studied by the XANES spectroscopy.

  3. Light Transmission through Sub-Wavelength Apertures

    E-Print Network [OSTI]

    Visser, Taco D.

    Light Transmission through Sub-Wavelength Apertures #12;#12;VRIJE UNIVERSITEIT Light Transmission Transmission through a Single Sub-wavelength Slit 59 3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 3.2 The configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 3.3 Transmission

  4. BIOMECHANICAL ENGINEERING SubPlan Requirements

    E-Print Network [OSTI]

    Cafarella, Michael J.

    BIOMECHANICAL ENGINEERING SubPlan Requirements Campus: UMICH RG = Requirement Group Career:UENG RQ = Requirement Program: LN = Line Plan: 0880BSE Sub-Plan: BIOMECH RG 6860 BIOMECHANICAL CONCENTRATION

  5. Electron backscatter diffraction analysis of gold nanoparticles on Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7??}

    SciTech Connect (OSTI)

    Bochmann, A.; Teichert, S.; Katzer, C.; Schmidl, F.

    2015-06-07

    It has been shown recently that the incorporation of gold nanoparticles into Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7??} enhances the superconducting properties of this material in a significant way. Previous XRD and TEM investigations suggest different crystallographic relations of the gold nanoparticles with respect to the epitaxial Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7??}. Here, detailed investigations of the crystal orientations for a large ensemble of gold nanoparticles with electron backscatter diffraction are reported. The average size of the gold nanoparticles is in the range of 60?nm–80?nm. We identified five different types of heteroepitaxial relationships between the gold nanoparticles and the superconductor film, resulting in complex pole figures. The observed different types of crystallographic orientations are discussed based on good lattice matching and the formation of low energy interfaces.

  6. Novel CO<sub>2sub> Foam Concepts and Injection Schemes for Improving CO<sub>2sub> Sweep Efficiency in Sandstone and Carbonate Hydrocarbon Formations

    SciTech Connect (OSTI)

    Nguyen, Quoc; Hirasaki, George; Johnston, Keith

    2015-02-05

    We explored cationic, nonionic and zwitterionic surfactants to identify candidates that have the potential to satisfy all the key requirements for CO<sub>2sub> foams in EOR. We have examined the formation, texture, rheology and stability of CO<sub>2sub> foams as a function of the surfactant structure and formulation variables including temperature, pressure, water/CO<sub>2 sub>ratio, surfactant concentration, salinity and concentration of oil. Furthermore, the partitioning of surfactants between oil and water as well as CO<sub>2sub> and water was examined in conjunction with adsorption measurements on limestone by the Hirasaki lab to develop strategies to optimize the transport of surfactants in reservoirs.

  7. Solar reduction of CO.sub.2

    DOE Patents [OSTI]

    Jensen, Reed J. (121 La Vista Dr., Los Alamos, NM 87544); Lyman, John L. (Los Alamos, NM); King, Joe D. (Los Alamos, NM); Guettler, Robert D. (Los Alamos, NM)

    2000-01-01

    The red shift of the absorption spectrum of CO.sub.2 with increasing temperature permits the use of sunlight to photolyze CO.sub.2 to CO. The process of the present invention includes: preheating CO.sub.2 to near 1800 K; exposing the preheated CO.sub.2 to sunlight, whereby CO, O.sub.2 and O are produced; and cooling the hot product mix by rapid admixture with room temperature CO.sub.2. The excess thermal energy may be used to produce electricity and to heat additional CO.sub.2 for subsequent process steps. The product CO may be used to generate H.sub.2 by the shift reaction or to synthesize methanol.

  8. SOUTHWEST REGIONAL PARTNERSHIP ON CARBON SEQUESTRATION

    SciTech Connect (OSTI)

    Brian McPherson; Rick Allis; Barry Biediger; Joel Brown; Jim Cappa; George Guthrie; Richard Hughes; Eugene Kim; Robert Lee; Dennis Leppin; Charles Mankin; Orman Paananen; Rajesh Pawar; Tarla Peterson; Steve Rauzi; Jerry Stuth; Genevieve Young

    2004-11-01

    The Southwest Partnership Region includes six whole states, including Arizona, Colorado, Kansas, New Mexico, Oklahoma, and Utah, roughly one-third of Texas, and significant portions of adjacent states. The Partnership comprises a large, diverse group of expert organizations and individuals specializing in carbon sequestration science and engineering, as well as public policy and outreach. The main objective of the Southwest Partnership project is to achieve an 18% reduction in carbon intensity by 2012. The Partnership made great progress in this first year. Action plans for possible Phase II carbon sequestration pilot tests in the region are almost finished, including both technical and non-technical aspects necessary for developing and carrying out these pilot tests. All partners in the Partnership are taking an active role in evaluating and ranking optimum sites and technologies for capture and storage of CO{sub 2} in the Southwest Region. We are identifying potential gaps in all aspects of potential sequestration deployment issues.

  9. Preparation and properties of ce-doped TiO{sub 2} photocatalyst

    SciTech Connect (OSTI)

    Yan, Ningning; Zhu, Zhongqi; Zhang, Jin [Yunnan Key Laboratory of Nanomaterials and Technology, Yunnan University, Kunming 650091 (China)] [Yunnan Key Laboratory of Nanomaterials and Technology, Yunnan University, Kunming 650091 (China); Zhao, Zongyan [School of Materials Science and Engineering, Kunming University of Science and Technology, Kunming 650093 (China)] [School of Materials Science and Engineering, Kunming University of Science and Technology, Kunming 650093 (China); Liu, Qingju, E-mail: qjliu@ynu.edu.cn [Yunnan Key Laboratory of Nanomaterials and Technology, Yunnan University, Kunming 650091 (China)] [Yunnan Key Laboratory of Nanomaterials and Technology, Yunnan University, Kunming 650091 (China)

    2012-08-15

    Highlights: ? The cerium ion doped TiO{sub 2} (Ce-TiO{sub 2}) powders were prepared and characterized. ? The spectrum absorption region of Ce-TiO{sub 2} is red-shifted to visible light. ? The recombination of photo-generated electron-hole pairs of Ce-TiO{sub 2} is inhibited. ? The photocatalytic activity was effected by Ce ion content and greatly improved. -- Abstract: TiO{sub 2} nanoparticles doped with different content of Ce ion were prepared by sol–gel method. The samples were characterized by XRD, XPS, TEM, UV–Vis, and PL, the photocatalytic activity was evaluated by photocatalytic degradation of methylene blue (MB) under the irradiation of fluorescent lamp. The results indicate that Ce ion is incorporated into the lattice of TiO{sub 2}, which can restrain the increase of grain size, broaden the absorption region to visible light, and inhibit the recombination of the photo-generated electron and hole pairs. Moreover, the photocatalytic activity of Ce-TiO{sub 2} in MB degradation is evidently enhanced. The MB degradation rate of the sample with Ce:Ti = 0.33% (molar ratio) in 8 h is 90.03%, which is much higher than that of P25 (68.19%).

  10. Conduction mechanisms in thin atomic layer deposited Al{sub 2}O{sub 3} layers

    SciTech Connect (OSTI)

    Spahr, Holger; Montzka, Sebastian; Reinker, Johannes; Hirschberg, Felix; Kowalsky, Wolfgang; Johannes, Hans-Hermann, E-mail: h2.johannes@ihf.tu-bs.de [Institut für Hochfrequenztechnik, Technische Universität Braunschweig, Schleinitzstraße 22, 38106 Braunschweig (Germany)

    2013-11-14

    Thin Al{sub 2}O{sub 3} layers of 2–135?nm thickness deposited by thermal atomic layer deposition at 80?°C were characterized regarding the current limiting mechanisms by increasing voltage ramp stress. By analyzing the j(U)-characteristics regarding ohmic injection, space charge limited current (SCLC), Schottky-emission, Fowler-Nordheim-tunneling, and Poole-Frenkel-emission, the limiting mechanisms were identified. This was performed by rearranging and plotting the data in a linear scale, such as Schottky-plot, Poole-Frenkel-plot, and Fowler-Nordheim-plot. Linear regression then was applied to the data to extract the values of relative permittivity from Schottky-plot slope and Poole-Frenkel-plot slope. From Fowler-Nordheim-plot slope, the Fowler-Nordheim-energy-barrier was extracted. Example measurements in addition to a statistical overview of the results of all investigated samples are provided. Linear regression was applied to the region of the data that matches the realistic values most. It is concluded that ohmic injection and therefore SCLC only occurs at thicknesses below 12?nm and that the Poole-Frenkel-effect is no significant current limiting process. The extracted Fowler-Nordheim-barriers vary in the range of up to approximately 4?eV but do not show a specific trend. It is discussed whether the negative slope in the Fowler-Nordheim-plot could in some cases be a misinterpreted trap filled limit in the case of space charge limited current.

  11. Electronic structure and magnetism of Mn{sub 12}O{sub 12} clusters

    SciTech Connect (OSTI)

    Pederson, M.R. [Complex Systems Theory Branch-6692, Naval Research Laboratory, Washington, D.C. 20375-5000 (United States)] [Complex Systems Theory Branch-6692, Naval Research Laboratory, Washington, D.C. 20375-5000 (United States); Khanna, S.N. [Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284-2000 (United States)] [Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284-2000 (United States)

    1999-01-01

    To address the ferrimagnetic state of the Mn{sub 12} acetate matrix [Mn{sub 12}O{sub 12}(CH{sub 3}COO){sub 16}(H{sub 2}O){sub 4}] we have performed all-electron gradient-corrected density-functional calculations on (MnO){sub n} with n=1, 2, 4, and 12. In contrast to bulk MnO which is antiferromagnetic, the small (MnO){sub n} (n=1, 2, and 4) clusters are ferromagnetic with Mn moments of 5.0{mu}{sub B} but the ground state of Mn{sub 12}O{sub 12} is ferrimagnetic with a total magnetic moment of 20.0{mu}{sub B} as observed experimentally. The inner Mn sites in Mn{sub 12}O{sub 12} are found to have localized moments of 4.1{mu}{sub B} which are antiferromagnetically coupled to two types of outer Mn with moments of 4.2{mu}{sub B}. The cluster is shown to be marked by ionic as well as covalent bonds between Mn d and O p electrons and a strong intracluster magnetic coupling. {copyright} {ital 1999} {ital The American Physical Society}

  12. Chemical stability of melt-cast refractories in K/sub 2/S/sub 2/O/sub 7/-V/sub 2/O/sub 5/ melt

    SciTech Connect (OSTI)

    Abanin, V.I.; Federov, A.A.; Malyavin, A.G.; Ketov, A.N.

    1983-02-20

    Melts based on V/sub 2/O/sub 5/ are promising as catalysts for conversion of sulfur dioxide and thermocatalytic decomposition of spent sulfuric acid. The high chemical activity of such media with respect to metallic materials necessitates development of new materials of construction not based on metals. The purpose of the present work was to study the influence the composition and structure of melt-cast refractories on their chemical stability in K/sub 2/S/sub 2/O/sub 7/-V/sub 2/O/sub 5/ melts. The chemical stability of refractories based on SiO/sub 2/ in K/sub 2/S/sub 2/O/sub 7/-V/sub 2/O/sub 5/ melt is raised by the presence of chain calcium silicates with pyroxene and pyroxenoid chains, and lowered in presence of the oxides of zirconium, zinc, and cobalt in the materials. Fused quartz, cor-93, cast stone of diopside composition, and basalt-dolomite cast stone have high chemical stability in K/sub 2/S/sub 2/O/sub 7/-V/sub 2/O/sub 5/ melt and can be recommended as construction materials for equipment used for thermocatalytic decomposition of spent sulfuric acid.

  13. High Schottky barrier at grain boundaries observed in Na{sub 1/2}Sm{sub 1/2}Cu{sub 3}Ti{sub 4}O{sub 12} ceramics

    SciTech Connect (OSTI)

    Somphan, Weeraya; Thongbai, Prasit; Yamwong, Teerapon; Maensiri, Santi

    2013-10-15

    Graphical abstract: - Highlights: • NSCTO exhibits a high ?? of 7.0–8.4 × 10{sup 3} and low tan ? of 0.030–0.041. • NSCTO exhibits a high E{sub b} of ?2208 V cm{sup ?1} and large ? of 15.6. • Giant ?? response is attributed to the electrically heterogeneous microstructure. • High ?{sub b} values at grain boundaries are found to be 0.925–0.964 eV. • Formation of a potential barrier at grain boundaries is caused by Schottky effect. - Abstract: The dielectric properties and nonlinear current–voltage characteristics of Na{sub 1/2}Sm{sub 1/2}Cu{sub 3}Ti{sub 4}O{sub 12} ceramics prepared by a conventional solid state reaction method were investigated. Na{sub 1/2}Sm{sub 1/2}Cu{sub 3}Ti{sub 4}O{sub 12} ceramics exhibited a high dielectric permittivity of 7.0–8.4 × 10{sup 3} and low loss tangent (tan ??0.030–0.041). Non-Ohmic properties with a high breakdown voltage of ?2208 V cm{sup ?1} and large nonlinear coefficient of 15.6 were observed in Na{sub 1/2}Sm{sub 1/2}Cu{sub 3}Ti{sub 4}O{sub 12} ceramics. Using complex impedance analysis, Na{sub 1/2}Sm{sub 1/2}Cu{sub 3}Ti{sub 4}O{sub 12} ceramics were shown to be electrically heterogeneous consisting of semiconducting grains and insulating grain boundaries. Giant dielectric properties were described based on the electrically heterogeneous microstructure. X-ray photoelectron spectroscopy analysis suggested that the semiconductive nature of grains may be related to the presence of Cu{sup +} and Ti{sup 3+}. The formation of an electrostatic potential barrier at the grain boundaries of Na{sub 1/2}Sm{sub 1/2}Cu{sub 3}Ti{sub 4}O{sub 12} ceramics was suggested to be caused by the Schottky effect. Interestingly, high electrostatic potential barriers at grain boundaries in Na{sub 1/2}Sm{sub 1/2}Cu{sub 3}Ti{sub 4}O{sub 12} ceramics were calculated and found to be 0.925–0.964 eV.

  14. Growth of large-domain YBa{sub 2}Cu{sub 3}O{sub x} with new seeding crystals of CaNdAlO{sub 4} and SrLaGaO{sub 4}.

    SciTech Connect (OSTI)

    Shi, D.; Hull, J. R.; LeBlanc, D.; LeBlanc, M. A. R.; Dabkowski, A.; Chang, Y.; Jiang, Y.; Zhang, Z.; Fan, H.; Energy Technology; Univ. of Cincinnati; Univ. of Ottawa; McMaster Univ.; Chinese Academy of Sciences

    1995-05-10

    Single crystals of CaNdAlO{sub 4} and SrLaGaO{sub 4} were used as seeds to grow large domains of YBa{sub 2}Cu{sub 3}O{sub x} for levitation applications. These crystals have high melting temperatures (> 1500 C) and similar lattice structures to that of YBa{sub 2}Cu{sub 3}O{sub x}. In a seeded melt-texturing method developed previously, the single crystals of CaNdAlO{sub 4}, SrLaGaO{sub 4}, and NdBa{sub 2}Cu{sub 3}O{sub x} were used as seeds for comparison. After melt processing, scanning electron microscopy analysis did not reveal any major differences in all these seeded melt-textured samples. However, the levitation forces in the samples seeded with single crystals of CaNdAlO{sub 4} and SrLaGaO{sub 4} increased considerably compared to that of the sample seeded with NdBa{sub 2}Cu{sub 3}O{sub x}. A model is proposed to describe the domain growth mechanism during seeded melt processing.

  15. Northwest Regional Technology Center

    E-Print Network [OSTI]

    management and public safety professionals to define and prioritize technology needs. Coordinate and leadNorthwest Regional Technology Center for Homeland Security The Northwest Regional Technology Center and deployment of technologies that are effective homeland security solutions for the region, and accelerate

  16. Evaluating Impacts of CO<sub>2sub> Intrusion into an Unconsolidated Aquifer. I. Experimental Data

    SciTech Connect (OSTI)

    Lawter, Amanda R.; Qafoku, Nikolla; Wang, Guohui; Shao, Hongbo; Brown, Christopher F.

    2015-08-04

    Capture and deep subsurface sequestration of CO<sub>2sub> has been identified as a potential mitigation technique for rising atmospheric CO<sub>2sub> concentrations. Sequestered CO<sub>2sub> represents a potential risk to overlying aquifers if the CO<sub>2sub> leaks from the deep storage reservoir. Batch and column experiments combined with wet chemical extractions were conducted to evaluate these risks to groundwater quality and to understand effects of CO<sub>2sub> leakage on aquifer chemistry and mineralogy. Sediments from the High Plains aquifer in Kansas, a confined sandstone aquifer, were used to study time-dependent release of major, minor and trace elements when exposed to CO<sub>2sub> gas. Results showed that Ca, Ba, Si, Mg, Sr, Na, and K increased either instantaneously or followed nonlinear increasing trends with time, indicating dissolution and/or desorption reactions controlled their release. Other elements, such as Mn and Fe, were also released from all sediments, creating a potential for redox reactions to occur. Results from acid extractions confirmed sediments had appreciable amounts of contaminants that may potentially be released into the aqueous phase. However, results from the batch and column experiments demonstrated that only a few trace elements (e.g., As, Cu, Cr, Pb) were released, indicating the risk of groundwater quality degradation due to exposure to leakage of sequestered CO<sub>2sub> is low. Concentrations of Mo were consistently higher in the control experiments (absence of CO<sub>2sub>) and were below detection in the presence of CO<sub>2sub> indicating a possible benefit of CO<sub>2sub> in groundwater aquifers. These investigations will provide useful information to support site selection, risk assessment, and public education efforts associated with geological CO<sub>2sub> storage and sequestration.

  17. White light generation from Dy{sup 3+}-doped ZnO-B{sub 2}O{sub 3}-P{sub 2}O{sub 5} glasses

    SciTech Connect (OSTI)

    Jayasimhadri, M.; Jang, Kiwan; Lee, Ho Sueb; Chen, Baojiu; Yi, Soung-Soo; Jeong, Jung-Hyun

    2009-07-01

    Dysprosium doped ZnO-B{sub 2}O{sub 3}-P{sub 2}O{sub 5} (ZBP) glasses were prepared by a conventional melt quenching technique in order to study the luminescent properties and their utility for white light emitting diodes (LEDs). X-ray diffraction spectra revealed the amorphous nature of the glass sample. The present glasses were characterized by infrared and Raman spectra to evaluate the vibrational features of the samples. The emission and excitation spectra were reported for the ZBP glasses. Strong blue (484 nm) and yellow (574 nm) emission bands were observed upon various excitations. These two emissions correspond to the {sup 4}F{sub 9/2}->{sup 6}H{sub 15/2} and {sup 4}F{sub 9/2}->{sup 6}H{sub 13/2} transitions of Dy{sup 3+} ions, respectively. Combination of these blue and yellow bands gives white light to the naked eye. First time, it was found that ZnO-B{sub 2}O{sub 3}-P{sub 2}O{sub 5} glasses efficiently emit white light under 400 and 454 nm excitations, which are nearly match with the emissions of commercial GaN blue LEDs and InGaN LED, respectively. CIE chromaticity coordinates also calculated for Dy{sup 3+}: ZBP glasses to evaluate the white light emission.

  18. Interfacial mode coupling as the origin of the enhancement of T<sub>c> in FeSe films on SrTiO<sub>3sub>

    SciTech Connect (OSTI)

    Lee, J. J.; Schmitt, F. T.; Moore, R. G.; Johnston, S.; Cui, Y. -T.; Li, W.; Yi, M.; Liu, Z. K.; Hashimoto, M.; Zhang, Y.; Lu, D. H.; Devereaux, T. P.; Lee, D. -H.; Shen, Z. -X.; /SIMES, Stanford /SLAC /Stanford U., Geballe Lab.

    2014-11-12

    Films of iron selenide (FeSe) one unit cell thick grown on strontium titanate (SrTiO<sub>3sub> or STO) substrates have recently shown superconducting energy gaps opening at temperatures close to the boiling point of liquid nitrogen (77 K), which is a record for the iron-based superconductors. The gap opening temperature usually sets the superconducting transition temperature T<sub>c>, as the gap signals the formation of Cooper pairs, the bound electron states responsible for superconductivity. To understand why Cooper pairs form at such high temperatures, we examine the role of the SrTiO<sub>3sub> substrate. Here we report high-resolution angle-resolved photoemission spectroscopy results that reveal an unexpected characteristic of the single-unit-cell FeSe/SrTiO<sub>3sub> system: shake-off bands suggesting the presence of bosonic modes, most probably oxygen optical phonons in SrTiO<sub>3sub>, which couple to the FeSe electrons with only a small momentum transfer. Such interfacial coupling assists superconductivity in most channels, including those mediated by spin fluctuations. Our calculations suggest that this coupling is responsible for raising the superconducting gap opening temperature in single-unit-cell FeSe/SrTiO<sub>3sub>.

  19. CO<sub>2sub> hydrogenation to formate and methanol as an alternative to photo- and electrochemical CO<sub>2sub> reduction

    SciTech Connect (OSTI)

    Wang, Wan -Hui; Himeda, Yuichiro; Muckerman, James T.; Manbeck, Gerald F.; Fujita, Etsuko

    2015-09-03

    In this study, carbon dioxide is one of the end products of combustion, and is not a benign component of the atmosphere. The concentration of CO<sub>2sub> in the atmosphere has reached unprecedented levels and continues to increase owing to an escalating rate of fossil fuel combustion, causing concern about climate change and rising sea levels. In view of the inevitable depletion of fossil fuels, a possible solution to this problem is the recycling of carbon dioxide, possibly captured at its point of generation, to fuels. Researchers in this field are using solar energy for CO<sub>2sub> activation and utilization in several ways: (i) so-called artificial photosynthesis using photo-induced electrons; (ii) bulk electrolysis of a CO<sub>2sub> saturated solution using electricity produced by photovoltaics; (iii) CO<sub>2sub> hydrogenation using solar-produced H<sub>2sub>; and (iv) the thermochemical reaction of metal oxides at extremely high temperature reached by solar collectors. Since the thermodynamics of CO<sub>2sub> at high temperature (> 1000 ºC) are quite different from those near room temperature, only chemistry below 200 ºC is discussed in this review.

  20. Mg{sub x}Zn{sub 1-x}O (x = 0-1) films fabricated by sol-gel spin coating

    SciTech Connect (OSTI)

    Caglar, Mujdat [Department of Physics, Faculty of Science, Anadolu University, 26470 Eskisehir (Turkey)] [Department of Physics, Faculty of Science, Anadolu University, 26470 Eskisehir (Turkey); Wu, Junshu; Li, Keyan [Department of Materials Science and Chemical Engineering, School of Chemical Engineering, Dalian University of Technology, Dalian 116012 (China)] [Department of Materials Science and Chemical Engineering, School of Chemical Engineering, Dalian University of Technology, Dalian 116012 (China); Caglar, Yasemin; Ilican, Saliha [Department of Physics, Faculty of Science, Anadolu University, 26470 Eskisehir (Turkey)] [Department of Physics, Faculty of Science, Anadolu University, 26470 Eskisehir (Turkey); Xue, Dongfeng, E-mail: dfxue@chem.dlut.edu.cn [Department of Materials Science and Chemical Engineering, School of Chemical Engineering, Dalian University of Technology, Dalian 116012 (China)] [Department of Materials Science and Chemical Engineering, School of Chemical Engineering, Dalian University of Technology, Dalian 116012 (China)

    2010-03-15

    Mg{sub x}Zn{sub 1-x}O films were deposited onto the glass substrate by a sol-gel spin coating method. The drying and annealing temperatures were 300 and 500 {sup o}C in air. As x varies from 0 to 1, it was observed that the crystal structure is changed from wurtzite ZnO to cubic MgO. The morphology characterizations of these films were observed by scanning electron microscope. The randomly oriented hexagonal nanorods were gown on the glass surface when x = 0 and 0.25, which became disappeared with increasing Mg contents. The optical properties of these films were investigated by room-temperature photoluminescence (PL) and UV-vis absorption spectra, which show that the optical band gap and photoluminescence in the visible and UV regions can be ideally tuned by varying the Mg contents in the Mg{sub x}Zn{sub 1-x}O alloy films.

  1. Synthesis and hydration behavior of calcium zirconium aluminate (Ca{sub 7}ZrAl{sub 6}O{sub 18}) cement

    SciTech Connect (OSTI)

    Kang, Eun-Hee [Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 151-744 (Korea, Republic of)] [Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 151-744 (Korea, Republic of); Yoo, Jun-Sang [Department of Oral and Maxillofacial Surgery, School of Dentistry, Seoul National University, Seoul 110-749 (Korea, Republic of)] [Department of Oral and Maxillofacial Surgery, School of Dentistry, Seoul National University, Seoul 110-749 (Korea, Republic of); Kim, Bo-Hye; Choi, Sung-Woo [Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 151-744 (Korea, Republic of)] [Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 151-744 (Korea, Republic of); Hong, Seong-Hyeon, E-mail: shhong@snu.ac.kr [Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 151-744 (Korea, Republic of)] [Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 151-744 (Korea, Republic of)

    2014-02-15

    Calcium zirconium aluminate (Ca{sub 7}ZrAl{sub 6}O{sub 18}) cements were prepared by solid state reaction and polymeric precursor methods, and their phase evolution, morphology, and hydration behavior were investigated. In polymeric precursor method, a nearly single phase Ca{sub 7}ZrAl{sub 6}O{sub 18} was obtained at relatively lower temperature (1200 °C) whereas in solid state reaction, a small amount of CaZrO{sub 3} coexisted with Ca{sub 7}ZrAl{sub 6}O{sub 18} even at higher temperature (1400 °C). Unexpectedly, Ca{sub 7}ZrAl{sub 6}O{sub 18} synthesized by polymeric precursor process was the large-sized and rough-shaped powder. The planetary ball milling was employed to control the particle size and shape. The hydration behavior of Ca{sub 7}ZrAl{sub 6}O{sub 18} was similar to that of Ca{sub 3}Al{sub 2}O{sub 6} (C3A), but the hydration products were Ca{sub 3}Al{sub 2}O{sub 6}·6H{sub 2}O (C3AH6) and several intermediate products. Thus, Zr (or ZrO{sub 2}) stabilized the intermediate hydration products of C3A.

  2. Luminescence properties of a blue-emitting phosphor: (Sr{sub 1?x}Eu{sub x})Si{sub 9}Al{sub 19}ON{sub 31} (0

    SciTech Connect (OSTI)

    Liu, Lihong; Xie, Rong-Jun; Hirosaki, Naoto; Dierre, Benjamin; Sekiguchi, Takashi

    2013-11-15

    Blue-emitting Sr{sub 1?x}Eu{sub x}Si{sub 9}Al{sub 19}ON{sub 31} phosphors were synthesized at 1800 °C for 2 h under 1 MPa N{sub 2} by using the gas-pressure sintering method (GPS). The microstructure, photoluminescence (PL) properties of the prepared phosphors were investigated. Under the 290 nm excitation, broad PL emission bands with peak positions at 448–490 nm were detected. The concentration quenching was not observed owing to the large distance betweenEu{sup 2+} ions that made the nonradiative energy transfer between neighboring Eu{sup 2+} ions difficult. The blue phosphor generally showed a small thermal quenching at low Eu{sup 2+} concentrations. The absorption and external quantum efficiency of the synthesized Sr{sub 0.5}Eu{sub 0.5}Si{sub 9}Al{sub 19}ON{sub 31} were 85% and 62% upon the 365 nm excitation, respectively. The interesting PL results indicate that Sr{sub 1?x}Eu{sub x}Si{sub 9}Al{sub 19}ON{sub 31} has great potentials as a blue phosphor for white LEDs applications. - Graphical abstract: Sr{sub 0.7}Eu{sub 0.3}Si{sub 9}Al{sub 19}ON{sub 31} gives blue-emitting at 471 nm. Excitation spectrum is composed of five bands in the range of 250–450 nm, which are matching well with emission wavelength of UV LEDs. Display Omitted - Highlights: • Blue-emitting Sr{sub 1?x}Eu{sub x}Si{sub 9}Al{sub 19}ON{sub 31} phosphors were synthesized by gas-pressure sintering method. • The concentration quenching was not observed in this phosphor. • This blue phosphor generally showed a small thermal quenching at low Eu{sup 2+} concentrations. • The absorption and external quantum efficiency of the synthesized Sr{sub 0.5}Eu{sub 0.5}Si{sub 9}Al{sub 19}ON{sub 31} were 85% and 62% upon the 365 nm excitation.

  3. Thermally-driven H interaction with HfO{sub 2} films deposited on Ge(100) and Si(100)

    SciTech Connect (OSTI)

    Soares, G. V. Feijó, T. O.; Baumvol, I. J. R.; Aguzzoli, C.; Krug, C.; Radtke, C.

    2014-01-27

    In the present work, we investigated the thermally-driven H incorporation in HfO{sub 2} films deposited on Si and Ge substrates. Two regimes for deuterium (D) uptake were identified, attributed to D bonded near the HfO{sub 2}/substrate interface region (at 300?°C) and through the whole HfO{sub 2} layer (400–600?°C). Films deposited on Si presented higher D amounts for all investigated temperatures, as well as, a higher resistance for D desorption. Moreover, HfO{sub 2} films underwent structural changes during annealings, influencing D incorporation. The semiconductor substrate plays a key role in this process.

  4. Photoluminescence in Pb{sub 0.95}Sr{sub 0.05}(Zr{sub 1?x}Ti{sub x}){sub 1?y}Cr{sub y}O{sub 3} ferroelectric ceramic system

    SciTech Connect (OSTI)

    Hernández-García, M.; Costa-Marrero, J.; Durruthy-Rodríguez, M. D.; Calderón-Piñar, F.; Guerra, J. D. S.; Yañez-Limón, J. M.

    2014-07-28

    Over the past several years, there has been a remarkable growth and development in new ceramic and/or composite materials to be used in the electro-electronic industry. Ferroelectric materials have been recognized for their multifunctional physical properties; also, their optical properties are a subject of intense research effort due to their possible electro-optic applications. In this work, the visible photoluminescence effect is analyzed at room temperature in a sintered Pb{sub 0.95}Sr{sub 0.05}(Zr{sub 1?x}Ti{sub x}){sub 1?y}Cr{sub y}O{sub 3} perovskite-type structure system, doped with Sr and Cr. The excitation bands used were 267, 325, 373, 457, 635, and 680?nm, but the best result was obtained at 373?nm. The intensity and energy of such emission in this system have been studied by changing the molar Cr concentration (0?

  5. Fluid Spatial Imaginaries: evolving estuarial city-regional spaces

    E-Print Network [OSTI]

    Haughton, Graham; Allmendinger, Phil

    2015-01-01

    , the reversals and re-imaginings involved in trying to imagine new estuary regions over a fifty year period. We develop an argument that over the course of fifty years it is possible to see a transition from policies that were largely framed territorially... and international logistics (Frey 1971; Glasson, 1974; Glasson and Marshall, 2007). Despite the contemporary denials of politicians about them influencing local government reforms, seen in retrospect it seems clear that the commissioned sub- regional studies did...

  6. Kondo hole behavior in Ce{sub 0.97} La{sub 0.03}Pd{sub 3}

    SciTech Connect (OSTI)

    Lawrence, J.M.; Graf, T.; Hundley, M.F.; Mandrus, D.; Thompson, J.D. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Lacerda, A.; Torikachvili, M.S. [National High Magnetic Field Laboratory, Pulse Facility, Los Alamos, New Mexico 87545 (United States)] [National High Magnetic Field Laboratory, Pulse Facility, Los Alamos, New Mexico 87545 (United States); Sarrao, J.L.; Fisk, Z. [National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306 (United States)] [National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306 (United States)

    1996-05-01

    We present results for the resistivity, the magnetoresistance, and the specific heat of Ce{sub 0.97}La{sub 0.03}Pd{sub 3} and CePd{sub 3}. The impurity contributions to these measurements follow the predictions of the single-impurity Kondo model for a Kondo temperature {ital T}{sub {ital L}}{approx_equal}65 K, assuming that the impurity behaves as a crystal-field split ({Gamma}{sub 7}) doublet. Assuming a {ital J}=5/2 impurity, the value of {ital T}{sub {ital L}} needed to fit these experiments varies from 65 to 125 K. The contribution to the susceptibility may be too small to be explained by the model. These results address whether the nonmagnetic impurity behaves as a Kondo hole. {copyright} {ital 1996 The American Physical Society.}

  7. Optical spectroscopic study of inverted cylindrical magnetron sputtering of YBa sub 2 Cu sub 3 O sub 7 minus x

    SciTech Connect (OSTI)

    Xi, X.X.; Wu, X.D.; Inam, A.; Li, Q.; Hemmick, D.; Findikoglu, A. ); Venkatesan, T.; Chang, C.C. ); Howard, R. )

    1990-07-02

    Optical spectroscopic studies of the plasma generated by inverted cylindrical magnetron sputtering of the high-temperature superconductor YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} reveal strong ionic emissions from cation elements as well as from the sputter gases. The emissions of cationic ions are weakened drastically when O{sub 2} is added into the sputter gas indicating the dominating role of ions in the reaction with oxygen to form gas phase oxides. The formation of gas phase oxides is proposed to be an important precursor step for the {ital in} {ital situ} deposition of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} thin films.

  8. Temperature driven transition from giant to tunneling magneto-resistance in Fe{sub 3}O{sub 4}/Alq{sub 3}/Co spin Valve: Role of Verwey transition of Fe{sub 3}O{sub 4}

    SciTech Connect (OSTI)

    Dey, P., E-mail: pujaiitkgp2007@gmail.com; Rawat, R.; Potdar, S. R.; Choudhary, R. J.; Banerjee, A. [UGC-DAE Consortium for Scientific Research (CSR), University Campus, Khandwa Road, Indore 452 001 (India)

    2014-05-07

    We demonstrate interface energy level engineering, exploiting the modification in energy band structure across Verwey transition temperature (T{sub V}) of Fe{sub 3}O{sub 4}, in a Fe{sub 3}O{sub 4}(111)/Alq{sub 3}/Co spin-valve (SV). I-V characteristics exhibit a transition in conduction mode from carrier injection to tunneling across T{sub V} of Fe{sub 3}O{sub 4} electrode. Both giant magneto-resistance (GMR) and tunneling MR (TMR) have been observed in a single SV, below and above T{sub V}, respectively. We have achieved room-temperature SV operation in our device. We believe that the tuning of charge gap at Fermi level across T{sub V} resulting in a corresponding tuning of conduction mode and a unique cross over from GMR to TMR.

  9. Evolution of Griffith's phase in La{sub 0.4}Bi{sub 0.6}Mn{sub 1?x}Ti{sub x}O{sub 3} perovskite oxide

    SciTech Connect (OSTI)

    Dayal, Vijaylakshmi Kumar, Punith V.; Hadimani, R. L.; Jiles, D. C.

    2014-05-07

    Samples of La{sub 0.4}Bi{sub 0.6}Mn{sub 1?x}Ti{sub x}O{sub 3} have been prepared and their microstructure, composition, and magnetic properties have been investigated for x?=?0.05, 0.1, and 0.5.The deviation in the inverse susceptibility behavior from Curie-Weiss law and increase in susceptibility exponent indicates the evolution of the Griffith's phase in La{sub 0.4}Bi{sub 0.6}Mn{sub 1?x}Ti{sub x}O{sub 3} around T{sub C}. The presence of Griffith's Phase is inferred due to magnetic frustration with increasing Ti concentration. The deviation between field cooled and zero field cooled magnetization curves is observed in these samples and is attributed to the appearance of the spin glass or cluster glass state that arises due to the magnetic anisotropy.

  10. Observational results of a multi-telescope campaign in search of interstellar urea [(NH{sub 2}){sub 2}CO

    SciTech Connect (OSTI)

    Remijan, Anthony J.; Snyder, Lewis E.; Kuo, Hsin-Lun; Looney, Leslie W.; Friedel, Douglas N.; McGuire, Brett A.; Golubiatnikov, G. Yu; Lovas, Frank J.; Ilyushin, V. V.; Alekseev, E. A.; Dyubko, S. F.; McCall, Benjamin J.; Hollis, Jan M.

    2014-03-10

    In this paper, we present the results of an observational search for gas phase urea [(NH{sub 2}){sub 2}CO] observed toward the Sgr B2(N-LMH) region. We show data covering urea transitions from ?100 GHz to 250 GHz from five different observational facilities: the Berkeley-Illinois-Maryland-Association (BIMA) Array, the Combined Array for Research in Millimeter-wave Astronomy (CARMA), the NRAO 12 m telescope, the IRAM 30 m telescope, and the Swedish-ESO Submillimeter Telescope (SEST). The results show that the features ascribed to urea can be reproduced across the entire observed bandwidth and all facilities by best-fit column density, temperature, and source size parameters which vary by less than a factor of two between observations merely by adjusting for telescope-specific parameters. Interferometric observations show that the emission arising from these transitions is cospatial and compact, consistent with the derived source sizes and emission from a single species. Despite this evidence, the spectral complexity of both (NH{sub 2}){sub 2}CO and of Sgr B2(N) makes the definitive identification of this molecule challenging. We present observational spectra, laboratory data, and models, and discuss our results in the context of a possible molecular detection of urea.

  11. Southeast Regional Carbon Sequestration Partnership (SECARB)

    SciTech Connect (OSTI)

    Kenneth J. Nemeth

    2005-09-30

    The Southeast Regional Carbon Sequestration Partnership (SECARB) is a diverse partnership covering eleven states involving the Southern States Energy Board (SSEB) an interstate compact; regulatory agencies and/or geological surveys from member states; the Electric Power Research Institute (EPRI); academic institutions; a Native American enterprise; and multiple entities from the private sector. Figure 1 shows the team structure for the partnership. In addition to the Technical Team, the Technology Coalition, an alliance of auxiliary participants, in the project lends yet more strength and support to the project. The Technology Coalition, with its diverse representation of various sectors, is integral to the technical information transfer, outreach, and public perception activities of the partnership. The Technology Coalition members, shown in Figure 2, also provide a breadth of knowledge and capabilities in the multiplicity of technologies needed to assure a successful outcome to the project and serve as an extremely important asset to the partnership. The eleven states comprising the multi-state region are: Alabama; Arkansas; Florida; Georgia; Louisiana; Mississippi; North Carolina; South Carolina; Tennessee; Texas; and Virginia. The states making up the SECARB area are illustrated in Figure 3. The primary objectives of the SECARB project include: (1) Supporting the U.S. Department of Energy (DOE) Carbon Sequestration Program by promoting the development of a framework and infrastructure necessary for the validation and deployment of carbon sequestration technologies. This requires the development of relevant data to reduce the uncertainties and risks that are barriers to sequestration, especially for geologic storage in the SECARB region. Information and knowledge are the keys to establishing a regional carbon dioxide (CO{sub 2}) storage industry with public acceptance. (2) Supporting the President's Global Climate Change Initiative with the goal of reducing greenhouse gas intensity by 18 percent by 2012. A corollary to the first objective, this objective requires the development of a broad awareness across government, industry, and the general public of sequestration issues and establishment of the technological and legal frameworks necessary to achieve the President's goal. The information developed by the SECARB team will play a vital role in achieving the President's goal for the southeastern region of the United States. (3) Evaluating options and potential opportunities for regional CO{sub 2} sequestration. This requires characterization of the region regarding the presence and location of sources of greenhouse gases (GHGs), primarily CO{sub 2}, the presence and location of potential carbon sinks and geological parameters, geographical features and environmental concerns, demographics, state and interstate regulations, and existing infrastructure.

  12. Site occupancy and cation binding states in reduced polycrystalline Sr{sub x}Ba{sub 1?x}Nb{sub 2}O{sub 6}

    SciTech Connect (OSTI)

    Dandeneau, Christopher S., E-mail: dandec@u.washington.edu; Yang, YiHsun; Ohuchi, Fumio S. [Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195 (United States)] [Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195 (United States); Krueger, Benjamin W.; Olmstead, Marjorie A. [Department of Physics, University of Washington, Seattle, Washington 98195 (United States)] [Department of Physics, University of Washington, Seattle, Washington 98195 (United States); Bordia, Rajendra K. [Department of Materials Science and Engineering, Clemson University, Clemson, South Carolina 29634 (United States)] [Department of Materials Science and Engineering, Clemson University, Clemson, South Carolina 29634 (United States)

    2014-03-10

    Site occupancy and cation binding states in the proposed thermoelectric n-type oxide Sr{sub x}Ba{sub 1?x}Nb{sub 2}O{sub 6} (SBN100x) were investigated using X-ray photoelectron spectroscopy (XPS). Sr 3d XPS spectra from unreduced polycrystalline SBN100x with various compositions contained two distinct spin-orbit doublets corresponding to Sr occupying either A1 or A2 positions in the SBN lattice; the higher binding energy state was associated with Sr ions at A2 sites, presumably due to their increased coordination over Sr at A1 sites. To gain insight into optimizing the thermoelectric properties of reduced SBN, sintered SBN50 specimens were reduced in Ar/H{sub 2} or N{sub 2}/H{sub 2} ambient. A decrease in the average Nb valence was observed in Nb 3d photoemission through the growth of low-binding energy components after reduction in either environment; evidence of surface NbN formation was apparent with longer reducing times in N{sub 2}/H{sub 2}. Both the single-component Ba 3d emission and the A2 component of the Sr 3d spectra show shifting to lower binding energy as the reduction time is increased, supporting the hypothesis of preferential oxygen vacancy formation adjacent to A2 sites. X-ray diffraction patterns revealed the formation of NbO{sub 2} in both reducing environments; in the case of extended reduction in N{sub 2}/H{sub 2}, NbO{sub 2} is gradually converted to NbN phases. Given the known properties of metallic NbN and semiconducting NbO{sub 2}, the findings obtained here may be used to maximize the thermoelectric performance of SBN via the fabrication of composite structures containing both NbO{sub 2} and NbN.

  13. Synthesis, characterization and magnetic property of a new 3D iron phosphite: |C{sub 4}N{sub 3}H{sub 14}|[Fe{sub 3}(HPO{sub 3}){sub 4}F{sub 2}(H{sub 2}O){sub 2}] with intersecting channels

    SciTech Connect (OSTI)

    Qiao Jian; Zhang Lirong; Yu Yang; Li Guanghua; Jiang Tianchan; Huo Qisheng; Liu Yunling

    2009-07-15

    A new open-framework iron (III) phosphite |C{sub 4}N{sub 3}H{sub 14}|[Fe{sub 3}(HPO{sub 3}){sub 4}F{sub 2}(H{sub 2}O){sub 2}] has been solvothermally synthesized by using diethylenetriamine (DETA) as the structure-directing agent. Single-crystal X-ray diffraction analysis reveals that the compound crystallizes in the monoclinic space group C2/c having unit cell parameters a=12.877(3) A, b=12.170(2) A, c=12.159(2) A, beta=93.99(3){sup o}, V=1900.9(7) A{sup 3}, and Z=4 with R{sub 1}=0.0447, wR{sub 2}=0.0958. The complex structure consists of HPO{sub 3} pseudo-tetrahedra and {l_brace}Fe{sub 3}O{sub 14}F{sub 2}{r_brace} trimer building units. The assembly of these building units generates 3D inorganic framework with intersecting 6-, 8-, and 10-ring channels. The DETA cations are located in the 10-ring channels linked by hydrogen bonds. The Moessbauer spectrum shows that there exhibit two crystallographically independent iron (III) atoms. And the magnetic investigation shows the presence of antiferromagnetic interactions. Further characterization of the title compound was performed using X-ray powder diffraction (XRD), infrared (IR) spectra, thermal gravimetric analyses (TGA), inductively coupled plasma (ICP) and elemental analyses. - Graphical abstract: A new three-dimensional iron phosphite with intersecting 6-, 8-, 10-ring channels has been solvothermally synthesized by using diethylenetriamine (DETA) as the structure-directing agent.

  14. Structural characterization and AC conductivity of bis tetrapropylammonium hexachlorado-dicadmate, [N(C{sub 3}H{sub 7}){sub 4}]{sub 2}Cd{sub 2}Cl{sub 6}

    SciTech Connect (OSTI)

    Hannachi, N.; Guidara, K.; Bulou, A.; Hlel, F.

    2010-11-15

    Synthesis, crystal structure, vibrational study, {sup 13}C, {sup 111}Cd CP-MAS-NMR analysis and electrical properties of the compound [N(C{sub 3}H{sub 7}){sub 4}]{sub 2}Cd{sub 2}Cl{sub 6}, are reported. The latter crystallizes in the triclinic system (space group P1-bar, Z = 2) with the following unit cell dimensions: a = 9.530(1) A, b = 11.744(1) A, c = 17.433(1) A, {alpha} = 79.31(1){sup o}, {beta} = 84.00(1){sup o} and {gamma} = 80.32(1){sup o}. Besides, its structure was solved using 6445 independent reflections down to R = 0.037. The atomic arrangement can be described by alternating organic and inorganic layers parallel to the (11-bar 0) plan, made up of tetrapropylammonium groups and Cd{sub 2}Cl{sub 6} dimers, respectively. In crystal structure, the inorganic layer, built up by Cd{sub 2}Cl{sub 6} dimers, is connected to the organic ones through van der Waals interaction in order to build cation-anion-cation cohesion. Impedance spectroscopy study, reported in the sample, reveals that the conduction in the material is due to a hopping process. The temperature and frequency dependence of dielectric constants of the single crystal sample has been investigated to determine some related parameters to the dielectric relaxation.

  15. Cathode encapsulation of organic light emitting diodes by atomic layer deposited Al{sub 2}O{sub 3} films and Al{sub 2}O{sub 3}/a-SiN{sub x}:H stacks

    SciTech Connect (OSTI)

    Keuning, W.; Weijer, P. van de; Lifka, H.; Kessels, W. M. M.; Creatore, M. [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Philips Research Laboratories, High Tech Campus 4, P.O. Box WAG12, 5656 AE Eindhoven (Netherlands); Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands)

    2012-01-15

    Al{sub 2}O{sub 3} thin films synthesized by plasma-enhanced atomic layer deposition (ALD) at room temperature (25 deg. C) have been tested as water vapor permeation barriers for organic light emitting diode devices. Silicon nitride films (a-SiN{sub x}:H) deposited by plasma-enhanced chemical vapor deposition served as reference and were used to develop Al{sub 2}O{sub 3}/a-SiN{sub x}:H stacks. On the basis of Ca test measurements, a very low intrinsic water vapor transmission rate of {<=} 2 x 10{sup -6} g m{sup -2} day{sup -1} and 4 x 10{sup -6} g m{sup -2} day{sup -1} (20 deg. C/50% relative humidity) were found for 20-40 nm Al{sub 2}O{sub 3} and 300 nm a-SiN{sub x}:H films, respectively. The cathode particle coverage was a factor of 4 better for the Al{sub 2}O{sub 3} films compared to the a-SiN{sub x}:H films and an average of 0.12 defects per cm{sup 2} was obtained for a stack consisting of three barrier layers (Al{sub 2}O{sub 3}/a-SiN{sub x}:H/Al{sub 2}O{sub 3}).

  16. Regional Climate Modeling: Progress, Challenges, and Prospects

    SciTech Connect (OSTI)

    Wang, Yuqing; Leung, Lai R.; McGregor, John L.; Lee, Dong-Kyou; Wang, Wei-Chyung; Ding, Yihui; Kimura, Fujio

    2004-12-01

    Regional climate modeling with regional climate models (RCMs) has matured over the past decade and allows for meaningful utilization in a broad spectrum of applications. In this paper, latest progresses in regional climate modeling studies are reviewed, including RCM development, applications of RCMs to dynamical downscaling for climate change assessment, seasonal climate predictions and climate process studies, and the study of regional climate predictability. Challenges and potential directions of future research in this important area are discussed, with the focus on those to which less attention has been given previously, such as the importance of ensemble simulations, further development and improvement of regional climate modeling approach, modeling extreme climate events and sub-daily variation of clouds and precipitation, model evaluation and diagnostics, applications of RCMs to climate process studies and seasonal predictions, and development of regional earth system models. It is believed that with both the demonstrated credibility of RCMs’ capability in reproducing not only monthly to seasonal mean climate and interannual variability but also the extreme climate events when driven by good quality reanalysis and the continuous improvements in the skill of global general circulation models (GCMs) in simulating large-scale atmospheric circulation, regional climate modeling will remain an important dynamical downscaling tool for providing the needed information for assessing climate change impacts and seasonal climate predictions, and a powerful tool for improving our understanding of regional climate processes. An internationally coordinated effort can be developed with different focuses by different groups to advance regional climate modeling studies. It is also recognized that since the final quality of the results from nested RCMs depends in part on the realism of the large-scale forcing provided by GCMs, the reduction of errors and improvement in physics parameterizations in both GCMs and RCMs remain a priority for climate modeling community.

  17. Sub-barrier capture with quantum diffusion approach

    E-Print Network [OSTI]

    V. V. Sargsyan; R. A. Kuzyakin; G. G. Adamian; N. V. Antonenko; W. Scheid; H. Q. Zhang

    2011-08-05

    With the quantum diffusion approach the behavior of capture cross sections and mean-square angular momenta of captured systems are revealed in the reactions with deformed and spherical nuclei at sub-barrier energies. With decreasing bombarding energy under the barrier the external turning point of the nucleus-nucleus potential leaves the region of short-range nuclear interaction and action of friction. Because of this change of the regime of interaction, an unexpected enhancement of the capture cross section is found at bombarding energies far below the Coulomb barrier. This effect is shown its worth in the dependence of mean-square angular momentum on the bombarding energy. From the comparison of calculated capture cross sections and experimental capture or fusion cross sections the importance of quasifission near the entrance channel is demonstrated for the actinidebased reactions and reactions with medium-heavy nuclei at extreme sub-barrier energies.

  18. Synthesis and crystal structure of a new open-framework iron phosphate (NH{sub 4}){sub 4}Fe{sub 3}(OH){sub 2}F{sub 2}[H{sub 3}(PO{sub 4}){sub 4}]: Novel linear trimer of corner-sharing Fe(III) octahedra

    SciTech Connect (OSTI)

    Mi, Jin-Xiao; Wang, Cheng-Xin; Chen, Ning; Li, Rong; Pan, Yuanming

    2010-12-15

    A new iron phosphate (NH{sub 4}){sub 4}Fe{sub 3}(OH){sub 2}F{sub 2}[H{sub 3}(PO{sub 4}){sub 4}] has been synthesized hydrothermally at HF concentrations from 0.5 to 1.2 mL. Single-crystal X-ray diffraction analysis reveals its three-dimensional open-framework structure (monoclinic, space group P2{sub 1}/n (No. 14), a=6.2614(13) A, b=9.844(2) A, c=14.271(3) A, {beta}=92.11(1){sup o}, V=879.0(3) A{sup 3}). This structure is built from isolated linear trimers of corner-sharing Fe(III) octahedra, which are linked by (PO{sub 4}) groups to form ten-membered-ring channels along [1 0 0]. This isolated, linear trimer of corner-sharing Fe(III) octahedra, [(FeO{sub 4}){sub 3}(OH){sub 2}F{sub 2}], is new and adds to the diverse linkages of Fe polyhedra as secondary building units in iron phosphates. The trivalent iron at octahedral sites for the title compound has been confirmed by synchrotron Fe K-edge XANES spectra and magnetic measurements. Magnetic measurements also show that this compound exhibit a strong antiferromagnetic exchange below T{sub N}=17 K, consistent with superexchange interactions expected for the linear trimer of ferric octahedra with the Fe-F-Fe angle of 132.5{sup o}. -- Graphical abstract: The three-dimensional open-framework structure of (NH{sub 4}){sub 4}Fe{sub 3}(OH){sub 2}F{sub 2}[H{sub 3}(PO{sub 4}){sub 4}] is built from a novel isolated, linear (FeO{sub 4}){sub 3}(OH){sub 2}F{sub 2} trimer of corner-sharing Fe(III) octahedra linked by PO{sub 4} tetrahedra. Display Omitted

  19. Nanocrystalline Cs{sub x}WO{sub 3} particles: Effects of N{sub 2} annealing on microstructure and near-infrared shielding characteristics

    SciTech Connect (OSTI)

    Liu, Jing-Xiao, E-mail: drliu-shi@dlpu.edu.cn [School of Textile and Material Engineering, Dalian Polytechnic University, Dalian 116034 (China); Institute of Multidisciplinary Research for Advanced Material, Tohoku University, Sendai, 980-8577,Japan (Japan); Shi, Fei; Dong, Xiao-Li; Xu, Qiang [School of Textile and Material Engineering, Dalian Polytechnic University, Dalian 116034 (China); Yin, Shu; Sato, Tsugio [Institute of Multidisciplinary Research for Advanced Material, Tohoku University, Sendai, 980-8577,Japan (Japan)

    2013-10-15

    In order to further improve the near-infrared shielding properties of cesium tungsten bronze (Cs{sub x}WO{sub 3}) for solar filter applications, Cs{sub x}WO{sub 3} particles were prepared by solvothermal reaction method and the effects of nitrogen annealing on the microstructure and near-infrared shielding properties of Cs{sub x}WO{sub 3} were investigated. The obtained Cs{sub x}WO{sub 3} samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and spectrophotometer. The results indicate that nanosheet-like Cs{sub x}WO{sub 3} particles with hexagonal structure began to transform into nanorods after annealed at temperature higher than 600 °C. The near-infrared shielding properties of Cs{sub x}WO{sub 3} particles could be further improved by N{sub 2} annealing at 500–700 °C. Particularly, the 500 °C-annealed Cs{sub x}WO{sub 3} samples in the N{sub 2} atmosphere showed best near-infrared shielding properties. It was suggested that the excellent near-infrared shielding ability of the 500 °C-annealed Cs{sub x}WO{sub 3} samples is correlated with its minimum O/W atomic ratio and most oxygen vacancies. Highlights: • N{sub 2} annealing could further improve the near-infrared (NIR) shielding of Cs{sub x}WO{sub 3}. • Effects of N{sub 2} annealing on microstructure and NIR shielding of Cs{sub x}WO{sub 3} were studied. • The 500 °C-N{sub 2}-annealed Cs{sub x}WO{sub 3} exhibited minimum O/W ratio and most oxygen vacancies. • The 500 °C-N{sub 2}-annealed Cs{sub x}WO{sub 3} particles exhibited best NIR shielding properties.

  20. Electrochemical sensing behaviour of Ni doped Fe{sub 3}O{sub 4} nanoparticles

    SciTech Connect (OSTI)

    Suresh, R.; Giribabu, K.; Manigandan, R.; Narayanan, V., E-mail: vnnara@yahoo.co.in [Department of Inorganic Chemistry, University of Madras, Guindy Campus, Chennai 600 025 (India); Vijayalakshmi, L. [Annai Veilankanni's College for Women (Arts and Science), Saidapet, Chennai 600015 (India); Stephen, A. [Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai 600 025 (India)

    2014-01-28

    Ni doped Fe{sub 3}O{sub 4} nanoparticles were synthesized by simple hydrothermal method. The prepared nanomaterials were characterized by X-ray diffraction analysis, DRS-UV-Visible spectroscopy and field emission scanning electron microscopy. The XRD confirms the phase purity of the synthesized Ni doped Fe{sub 3}O{sub 4} nanoparticles. The optical property of Ni doped Fe{sub 3}O{sub 4} nanoparticles were studied by DRS UV-Visible analysis. The electrochemical sensing property of pure and Ni doped Fe{sub 3}O{sub 4} nanoparticles were examined using uric acid as an analyte. The obtained results indicated that the Ni doped Fe{sub 3}O{sub 4} nanoparticles exhibited higher electrocatalytic activity towards uric acid.

  1. Effect of Eu substitution on superconductivity in Ba{sub 8?x}Eu{sub x}Al{sub 6}Si{sub 40} clathrates

    SciTech Connect (OSTI)

    Liu, Lihua; Bi, Shanli; Peng, Bailu; Li, Yang

    2015-05-07

    The silicon clathrate superconductor is uncommon as its structure is dominated by strong Si-Si covalent bonds, rather than the metallic bond, that are more typical of traditional superconductors. To understand the influence of large magnetic moment of Eu on superconductivity for type-I clathrates, a series of samples with the chemical formula Ba{sub 8?x}Eu{sub x}Al{sub 6}Si{sub 40} (x?=?0, 0.5, 1, and 2) were synthesised in which Eu occupied Ba sites in cage center. With the increase of Eu content, the cubic lattice parameter decreases monotonically signifying continuous shrinkage of the constituting (Ba/Eu)@Si{sub 20} and (Ba/Eu)@Si{sub 24} cages. The temperature dependence of magnetization at low temperature revealed that Ba{sub 8}Al{sub 6}Si{sub 40} is superconductive with transition temperature at T{sub C}?=?5.6?K. The substitution of Eu for Ba results in a strong superconductivity suppression; Eu-doping largely decreases the superconducting volume and transition temperature T{sub C}. Eu atoms enter the clathrate lattice and their magnetic moments break paired electrons. The Curie-Weiss temperatures were observed at 3.9, 6.6, and 10.9?K, respectively, for samples with x?=?0.5, 1.0, and 2.0. Such ferromagnetic interaction of Eu can destroy superconductivity.

  2. Vapor-liquid equilibrium of the Mg(NO/sub 3/)/sub 2/-HNO/sub 3/-H/sub 2/O system

    SciTech Connect (OSTI)

    Thompson, B.E.; Derby, J.J.; Stalzer, E.H.

    1983-06-01

    The vapor-liquid equilibrium of the Mg(NO/sub 3/)/sub 2/-HNO/sub 3/-H/sub 2/O system in concentrations of 0 to 70 wt % Mg(NO/sub 3/)/sub 2/ and 0 to 75 wt % HNO/sub 3/ at atmospheric pressure was correlated by two approaches. One was based on a dissociation equilibrium expression in which the activities of the reacting species (HNO/sub 3/, NO/sub 3//sup -/, and H/sup +/) were approximated with mole fractions. The activity coefficients of the undissociated HNO/sub 3/ and H/sub 2/O were correlated as functions of the concentrations of magnesium nitrate and nitric acid by second-order polynomials. The average absolute difference between predicted and experimental values was 8% for the mole fraction of acid in the vapor and 8/sup 0/K for the bubble-point temperature. The second approach was to correlate the mean ionic rational activity coefficient of water with a form of the excess Gibbs energy composed of two terms. One term, a function of the ionic strength, accounts for the coulombic (ionic) interactions; the other term accounts for the non-coulombic (molecular) interactions. The average absolute difference between predicted and experimental values was 9% for the mole fraction of acid in the vapor, and 10/sup 0/K for the bubble-point temperature.

  3. Accuracy of the centrifugal sudden approximation in the H + CHD{sub 3} ? H{sub 2} + CD{sub 3} reaction

    SciTech Connect (OSTI)

    Zhang, Zhaojun; Chen, Jun; Liu, Shu; Zhang, Dong H.

    2014-06-14

    The initial state selected time-dependent wave packet method has been extended to calculate the coupled-channel reaction probabilities with total angular momentum J{sub tot} > 0 for the title reaction with seven degrees of freedom included. Fully converged integral cross sections were obtained for the ground and a number of vibrational excited initial states on a new potential energy surface recently constructed by this group using neural network fitting. As found from a previous study with the centrifugal sudden (CS) approximation, all these initial vibrational excitations investigated in this study enhance the reactivity considerably at a given collision energy, in particular the CH stretch excited state. The energy initially deposited in CH stretch motion is more effective than translational energy on promoting the reaction in the entire energy region, while for CH bending or CD{sub 3} umbrella excitations only at the high collision energy the vibrational energy becomes more effective. Our calculations also revealed that the accuracy of the CS approximation considerably deteriorates with the increase of J{sub tot}, in particular on the threshold energy. The CS approximation underestimates the integral cross sections for all these initial states, albeit not very severely. In general, it works better at high collision energies and for vibrationally excited initial states, with the increase of integral cross section.

  4. Sandia Energy - SubTER

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory ofDid youOxygenLaboratory FellowsStationary PowerTaraSubTER Home Climate

  5. Impurity effects in superconducting UPt sub 3

    SciTech Connect (OSTI)

    Aronson, M.C. (The Harrison M. Randall Laboratory of Physics, The University of Michigan, Ann Arbor, Michigan 48109 (USA)); Vorenkamp, T.; Koziol, Z.; de Visser, A.; Bakker, K.; Franse, J.J.M. (Natuurkundig Laboratorium der Universiteit van Amsterdam, Valckenierstraat 65, 1018 XE Amsterdam, The Netherlands (USA)); Smith, J.L. (Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (USA))

    1991-04-15

    Superconducting UPt{sub 3} is characterized by a novel and complex magnetic field-temperature phase diagram, with two superconducting transitions at {ital T}{sub {ital c}1} and {ital T}{sub {ital c}2} in zero field. We have studied the effects of Pd and Y impurities on the zero field superconducting properties of UPt{sub 3}. Resistance measurements show that both dopants increase the residual resistivity and decrease the spin fluctuation temperature in the normal state. {ital T}{sub {ital c}1} is depressed by both dopants, but more effectively by Pd. {vert bar}{ital T}{sub {ital c}1} {minus} {ital T}{sub {ital c}2}{vert bar} is essentially unaffected by Y doping, but increases dramatically with Pd doping.

  6. Ordered binary oxide films of V{sub 2}O{sub 3}(0001) on Al{sub 2}O{sub 3}

    SciTech Connect (OSTI)

    Guo, Q.; Kim, D.Y.; Street, S.C.; Goodman, D.W.

    1999-07-01

    Ordered binary oxide films of vanadium oxide have been prepared on an aluminum oxide film supported on Mo(110) under ultrahigh vacuum conditions and characterized by various surface analytical techniques. Auger electron spectroscopy, low energy electron diffraction, high-resolution electron loss spectroscopy, x-ray photoelectron spectroscopy and ion scattering spectroscopy indicate that the vanadia films grow epitaxially on the Al{sub 2}O{sub 3}/Mo(110) surface as V{sub 2}O{sub 3}(0001). The results of electronic structural measurements show an increase in the energy of the a{sub 1g} level in the 3{ital d} band at low temperatures, which is a possible explanation for the metal-to-insulator transition in V{sub 2}O{sub 3}. {copyright} {ital 1999 American Vacuum Society.}

  7. Comparison of the crystal and electronic structures of three 2:1 salts of the organic donor molecule BEDT-TTF with pentafluorothiomethylsulfonate anions SF{sub 5}CH{sub 2}SO{sub 3}{sup {minus}}, SF{sub 5}CHFSO{sub 3}{sup {minus}}, and SF{sub 5}CF{sub 2}SO{sub 3}{sup {minus}}

    SciTech Connect (OSTI)

    Ward, B.H.; Schlueter, J.A.; Geiser, U. [and others] [and others

    2000-02-01

    Salts of the donor molecule, bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF or ET), with pentafluorothiomethylsulfonate (SF{sub 5}CX{sub 2}SO{sub 3}{sup {minus}}, X = H or F) anions have been prepared. Three phases, {beta}{double_prime}-(ET){sub 2}SF{sub 5}CH{sub 2}SO{sub 3}{beta}{prime}-(ET){sub 2}SF{sub 5}CF{sub 2}SO{sub 3} and {beta}{double_prime}-(ET){sub 2}SF{sub 5}CHFSO{sub 3} (A,B, and C respectively) were obtained by electrocrystallization with the corresponding LiSF{sub 5}CX{sub 2}SO{sub 3} electrolytes. The structures of these salts were determined by single-crystal X-ray diffraction, and their physical properties were examined by electrical resistivity measurements as well as by ESR and Raman spectroscopy. The A,C and B salts are considerably different in their crystal structures, physical properties, and electronic structures despite the similarity in the structures of SF{sub 5}CX{sub 2}SO{sub 3}{sup {minus}}(X = H,F) anions. The A salt has two kinds of ET donor molecules with considerably different charge densities. The electronic structure of C has both one-dimensional (1D) and two-dimensional (2D) Fermi surfaces which are similar to those found in the organic superconductor A. The ESR data for the B salt indicate that it opens a spin gap below 45 K. The differences in the physical properties of the three salts were analyzed by calculating the HOMO-HOMO interaction energies between nearest-neighbor ET molecules in their donor molecule layers.

  8. Potential Impacts of Plug-in Hybrid Electric Vehicles on Regional Power Generation

    SciTech Connect (OSTI)

    Hadley, Stanton W; Tsvetkova, Alexandra A

    2008-01-01

    Plug-in hybrid electric vehicles (PHEVs) are being developed around the world, with much work aiming to optimize engine and battery for efficient operation, both during discharge and when grid electricity is available for recharging. However, the general expectation has been that the grid will not be greatly affected by the use of PHEVs because the recharging will occur during off-peak hours, or the number of vehicles will grow slowly enough so that capacity planning will respond adequately. This expectation does not consider that drivers will control the timing of recharging, and their inclination will be to plug in when convenient, rather than when utilities would prefer. It is important to understand the ramifications of adding load from PHEVs onto the grid. Depending on when and where the vehicles are plugged in, they could cause local or regional constraints on the grid. They could require the addition of new electric capacity and increase the utilization of existing capacity. Usage patterns of local distribution grids will change, and some lines or substations may become overloaded sooner than expected. Furthermore, the type of generation used to meet the demand for recharging PHEVs will depend on the region of the country and the timing of recharging. This paper analyzes the potential impacts of PHEVs on electricity demand, supply, generation structure, prices, and associated emission levels in 2020 and 2030 in 13 regions specified by the North American Electric Reliability Corporation (NERC) and the U.S. Department of Energy's (DOE's) Energy Information Administration (EIA), and on which the data and analysis in EIA's Annual Energy Outlook 2007 are based (Figure ES-1). The estimates of power plant supplies and regional hourly electricity demand come from publicly available sources from EIA and the Federal Energy Regulatory Commission. Electricity requirements for PHEVs are based on analysis from the Electric Power Research Institute, with an optimistic projection of 25% market penetration by 2020, involving a mixture of sedans and sport utility vehicles. The calculations were done using the Oak Ridge Competitive Electricity Dispatch (ORCED) model, a model developed over the past 12 years to evaluate a wide variety of critical electricity sector issues. Seven scenarios were run for each region for 2020 and 2030, for a total of 182 scenarios. In addition to a base scenario of no PHEVs, the authors modeled scenarios assuming that vehicles were either plugged in starting at 5:00 p.m. (evening) or at 10:00 p.m.(night) and left until fully charged. Three charging rates were examined: 120V/15A (1.4 kW), 120V/20A (2 kW), and 220V/30A (6 kW). Most regions will need to build additional capacity or utilize demand response to meet the added demand from PHEVs in the evening charging scenarios, especially by 2030 when PHEVs have a larger share of the installed vehicle base and make a larger demand on the system. The added demands of evening charging, especially at high power levels, can impact the overall demand peaks and reduce the reserve margins for a region's system. Night recharging has little potential to influence peak loads, but will still influence the amount and type of generation.

  9. Wavelength-dependent optical enhancement of superconducting interlayer coupling in La<sub>1.885sub>Ba>0.115sub>CuO>4sub>

    SciTech Connect (OSTI)

    Casandruc, E.; Nicoletti, D.; Rajasekaran, S.; Laplace, Y.; Khanna, V.; Gu, G.; Hill, J. P.; Cavalleri, A.

    2015-05-05

    We analyze the pump wavelength dependence for the photo-induced enhancement of interlayer coupling in La<sub>1.885sub>Ba>0.115sub>CuO>4sub>, which is promoted by optical melting of the stripe order. In the equilibrium superconducting state (T < TC = 13 K), in which stripes and superconductivity coexist, time-domain THz spectroscopy reveals a photo-induced blue-shift of the Josephson Plasma Resonance after excitation with optical pulses polarized perpendicular to the CuO2 planes. In the striped, non-superconducting state (TC < T < TSO ? 40 K) a transient plasma resonance similar to that seen below TC appears from a featureless equilibrium reflectivity. Most strikingly, both these effects become stronger upon tuning of the pump wavelength from the mid-infrared to the visible, underscoring an unconventional competition between stripe order and superconductivity, which occurs on energy scales far above the ordering temperature.

  10. Gamma ray shielding and structural properties of Bi{sub 2}O{sub 3}?PbO?B{sub 2}O{sub 3}?V{sub 2}O{sub 5} glass system

    SciTech Connect (OSTI)

    Kaur, Kulwinder, E-mail: kanwarjitsingh@yahoo.com; Singh, K. J., E-mail: kanwarjitsingh@yahoo.com; Anand, Vikas, E-mail: kanwarjitsingh@yahoo.com [Department of Physics, Guru Nanak Dev University, Amritsar 143005 (India)

    2014-04-24

    The present work has been undertaken to evaluate the applicability of Bi{sub 2}O{sub 3}?PbO?B{sub 2}O{sub 3}?V{sub 2}O{sub 5} glass system as gamma ray shielding material. Gamma ray mass attenuation coefficient has been determined theoretically using WinXcom computer software developed by National Institute of Standards and Technology. A meaningful comparison of their radiation shielding properties has been made in terms of their half value layer parameter with standard radiation shielding concrete 'barite'. Structural properties of the prepared glass system have been investigated in terms of XRD and FTIR techniques in order to check the possibility of their commercial utility as alternate to conventional concrete for gamma ray shielding applications.

  11. Charge control of antiferromagnetism at PbZr{sub 0.52}Ti{sub 0.48}O{sub 3}/La{sub 0.67}Sr{sub 0.33}MnO{sub 3} interface

    SciTech Connect (OSTI)

    Ma, X.; Zhai, H.; Fang, F.; Lüpke, G., E-mail: gxluep@wm.edu [Department of Applied Science, College of William and Mary, 251 Jamestown Road, Williamsburg, Virginia 23187 (United States); Kumar, A. [Department of Physics and Institute for Functional Nanomaterials, University of Puerto Rico, San Juan, Puerto Rico 00931-3343 (United States); CSIR-National Physical Laboratory, New Delhi 110012 (India); Dussan, S.; Katiyar, R. S. [Department of Physics and Institute for Functional Nanomaterials, University of Puerto Rico, San Juan, Puerto Rico 00931-3343 (United States); Zhao, H. B. [Department of Optical Science and Engineering, Fudan University, 220 Handan Road, Shanghai 200433 (China); Scott, J. F. [Department of Physics and Institute for Functional Nanomaterials, University of Puerto Rico, San Juan, Puerto Rico 00931-3343 (United States); Department of Physics, Cavendish Laboratory, University of Cambridge, Cambridge CB3 OHE (United Kingdom)

    2014-03-31

    The interfacial spin state of the multiferroic heterostructure PbZr{sub 0.52}Ti{sub 0.48}O{sub 3}/La{sub 0.67}Sr{sub 0.33}MnO{sub 3} and its dependence on ferroelectric polarization is investigated with magnetic second-harmonic generation at 78?K. The spin alignment of Mn ions in the first unit cell layer at the heterointerface can be tuned from ferromagnetic to antiferromagnetic exchange coupled, while the bulk magnetization remains unchanged. Multiple domains of both phases coexist as the ferroelectric polarization is switched. The results will help promote the development of new interface-based functionalities and device concepts.

  12. Study of phase relationships in the Sr{sub 3}(PO{sub 4}){sub 2}–CePO{sub 4} system. Phase diagram and thermal characteristics of phases

    SciTech Connect (OSTI)

    Matraszek, Aleksandra, E-mail: aleksandra.matraszek@ue.wroc.pl

    2013-07-15

    A diagram representing phase relationships in the Sr{sub 3}(PO{sub 4}){sub 2}–CePO{sub 4} phosphate system has been developed on the basis of results obtained by thermal analysis (DTA/DSC/TGA) and X-ray diffraction (XRD) methods. One intermediate compound with the formula Sr{sub 3}Ce(PO{sub 4}){sub 3} occurs in the Sr{sub 3}(PO{sub 4}){sub 2}–CePO{sub 4} system at temperatures exceeding 1045 °C. The compound has a eulytite structure with the following structural parameters: a=b=c=10.1655(8) Å, ?=?=?=90.00°, V=1050.46(6) Å{sup 3}. It's melting point exceeds 1950 °C. A limited solid solution exists in the system, which possesses the structure of a low-temperature form of Sr{sub 3}(PO{sub 4}){sub 2}. At 1000 °C the maximal concentration of CePO{sub 4} in the solid solution is below 20 mol%. The solid solution phase field narrows with increased temperature. There is a eutectic point in the (Sr{sub 3}(PO{sub 4}){sub 2}+Sr{sub 3}Ce(PO{sub 4}){sub 3}) phase field at 1765 °C and 15 mol% of CePO{sub 4}. The melting temperature of Sr{sub 3}(PO{sub 4}){sub 2} is 1882±15 °C. - Graphical abstract: The phase diagram of Sr{sub 3}(PO{sub 4}){sub 2}–CePO{sub 4} system showing the stability ranges of limited solid solution and Sr{sub 3}Ce(PO{sub 4}){sub 3} phases. - Highlights: • Sr{sub 3}(PO{sub 4}){sub 2} melts at 1882 °C. • Phase diagram of Sr{sub 3}(PO{sub 4}){sub 2}–CePO{sub 4} system has been proposed. • Limited solid solution of CePO{sub 4} in Sr{sub 3}(PO{sub 4}){sub 2} forms in the system. • The Sr{sub 3}Ce(PO{sub 4}){sub 2} phosphate is stable at temperatures above 1045 °C.

  13. Transition threshold in Ge{sub x}Sb{sub 10}Se{sub 90?x} glasses

    SciTech Connect (OSTI)

    Wei, Wen-Hou [Department of Applied Physics, Chongqing University, Chongqing 401331 (China); Centre for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS), Laser Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Fang, Liang, E-mail: lfang@cqu.edu.cn [Department of Applied Physics, Chongqing University, Chongqing 401331 (China); Shen, Xiang [Laboratory of Infrared Material and Devices, Advanced Technology Research Institute, Ningbo University, Ningbo 315211 (China); Wang, Rong-Ping [Centre for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS), Laser Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia)

    2014-03-21

    Ge{sub x}Sb{sub 10}Se{sub 90?x} glasses with Ge content from 7.5 to 32.5?at.?% have been prepared by melt-quench technique, and the physical parameters including glass transition temperature (T{sub g}), density (?), compactness (C), shear elastic moduli (C{sub s}), compression elastic moduli (C{sub c}), refractive index (n), and optical bandgap (E{sub g}) have been investigated. While all these physical parameters show threshold behavior in the glass with a chemically stoichiometric composition. Raman spectra analysis also indicates that, with increasing Ge content, Se-chains or rings gradually disappear until all Se-atoms are consumed in the glass with a chemically stoichiometric composition. With further increasing Ge content, homopolar Ge-Ge and Sb-Sb bonds are formed and the chemical order in the glasses is violated. The threshold behavior of the physical properties in the Ge{sub x}Sb{sub 10}Se{sub 90?x} glasses can be traced to demixing of networks above the chemically stoichiometric composition.

  14. Structural and superconducting properties of neodymium added (Bi,Pb){sub 2}Sr{sub 2}CaCu{sub 2}O{sub y}

    SciTech Connect (OSTI)

    Biju, A.; Sarun, P.M. [Regional Research Laboratory (CSIR), Trivandrum, Kerala 695019 (India); Aloysius, R.P. [National Physical Laboratory (CSIR), New Delhi 110012 (India); Syamaprasad, U. [Regional Research Laboratory (CSIR), Trivandrum, Kerala 695019 (India)], E-mail: syam@csrrltrd.ren.nic.in

    2007-12-04

    The effects of neodymium (Nd) addition on the phase evolution, structural and superconducting properties of (Bi,Pb){sub 2}Sr{sub 2}CaCu{sub 2}O{sub y} [(Bi,Pb)-2212] prepared by solid state synthesis in bulk polycrystalline form were studied. The Nd content was varied from x = 0 to 0.5 on a general stoichiometry of Bi{sub 1.7}Pb{sub 0.4}Sr{sub 2.0}Ca{sub 1.1}Cu{sub 2.1}Nd{sub x}O{sub y}. The samples were characterized by differential thermal analysis (DTA), powder X-ray diffraction, scanning electron microscopy (SEM) equipped with energy dispersive X-ray analysis (EDX), resistance-temperature (R-T) measurements and superconductivity measurements at 64 K. It was found that the melting temperature of (Bi,Pb)-2212 slightly increases and the endotherm broadens due to the Nd-addition. The c-lattice parameter initially decreases and then increases with Nd addition. The critical temperature (T{sub C}) and the critical current density (J{sub C}) of the added samples are highly enhanced. The added sample shows a maximum onset critical temperature (T{sub C-onset}) of 95.56 K (x = 0.3) and a maximum critical current density of 719 A/cm{sup 2} at 64 K (x = 0.2) against 76.7 K and 100 A/cm{sup 2}, respectively, for the pure sample. The results show that the enhancement in superconducting properties are not due to any improvement in microstructure or grain growth, but due to a decrease in hole concentration as a result of Nd doping, which changes the system from 'over-doped condition' to 'optimally doped condition'.

  15. Luminescence and superradiance in electron-beam-excited Al{sub x}Ga{1-sub x}N

    SciTech Connect (OSTI)

    Bokhan, P. A.; Gugin, P. P.; Zakrevsky, Dm. E.; Malin, T. V.; Zhuravlev, K. S.; Osinnykh, I. V.; Solomonov, V. I.; Spirina, A. V.

    2014-09-21

    Luminescence and superradiance characteristics of 0.5–1.2-?m thick Al{sub x}Ga{sub 1-x}N films grown by molecular-beam epitaxy on sapphire substrates were studied under excitation of the films with low-energy (<20 keV) and high-energy (170 keV) electron beams. In both cases, the luminescence spectra looked quite similarly; they exhibited a band-edge luminescence with x-dependent wavelength ranging from 365 nm to 310 nm and a broadband emission taking over the whole visible spectral region. Superradiance within the broad band was obtained by pumping the samples with powerful an electron beam in the form of an open-discharge-generated filament.

  16. Rare-earth-rich tellurides: Gd{sub 4}NiTe{sub 2} and Er{sub 5}M{sub 2}Te{sub 2} (M=Co, Ni)

    SciTech Connect (OSTI)

    Magliocchi, Carmela; Meng, Fanqin; Hughbanks, Timothy . E-mail: trh@mail.chem.tamu.edu

    2004-11-01

    Three new rare earth metal-rich compounds, Gd{sub 4}NiTe{sub 2}, and Er{sub 5}M{sub 2}Te{sub 2} (M=Ni, Co), were synthesized in direct reactions using R, R{sub 3}M, and R{sub 2}Te{sub 3} (R=Gd, Er; M=Co, Ni) and single-crystal structures were determined. Gd{sub 4}NiTe{sub 2} is orthorhombic and crystallizes in space group Pnma with four formula units per cell. Lattice parameters at 110(2)K are a=15.548(9), b=4.113(2), c=11.7521(15)A. Er{sub 5}Ni{sub 2}Te{sub 2} and Er{sub 5}Co{sub 2}Te{sub 2} are isostructural and crystallize in the orthorhombic space group Cmcm with two formula units per cell. Lattice parameters at 110(2)K are a=3.934(1), b=14.811(4), c=14.709(4)A, and a=3.898(1), b=14.920(3), c=14.889(3)A, respectively. Metal-metal bonding correlations were analyzed using the empirical Pauling bond order concept.

  17. Pressure-dependent magnetism and electrical resistivity of UFe/sub 4/P/sub 12/

    SciTech Connect (OSTI)

    Guertin, R.P.; Rossel, C.; Torikachvili, M.S.; McElfresh, M.W.; Maple, M.B.; Bloom, S.H.; Yao, Y.S.; Kuric, M.V.; Meisner, G.P.

    1987-12-01

    UFe/sub 4/P/sub 12/ is the first reported uranium-based ferromagnetic semiconductor. The Curie temperature T/sub C/ is 3.15 K, and the spontaneous magnetic moment sigma/sub 0/ which at T = 1.14 K was found to be approx. =1.0 ..mu../sub B//(U atom), is associated entirely with the uranium ions. The electrical resistivity rho(T) increases by nearly 7 orders of magnitude as temperature is decreased from room temperature to 4.2 K. The behavior of the ferromagnetic and electrical properties of UFe/sub 4/P/sub 12/ in hydrostatic pressures up to 16 kbar is reported. Quasihydrostatic-pressure effects on rho(T) to 100 kbar are also reported. Although T/sub C/ increases sharply with increasing pressure at the rate dT/sub C//dP = 0.26 K/kbar (in contrast to similar data on the isomorphic ferromagnet NdFe/sub 4/P/sub 12/, where dT/sub C//dP = 0.03 K/kbar), sigma/sub 0/ decreases, (1/sigma/sub 0/)(dsigma/sub 0//dp) = -0.007 kbar/sup -1/. Hydrostatic and quasihydrostatic pressure have little effect on rho(T).

  18. Ordered nanoporous carbon for increasing CO{sub 2} capture

    SciTech Connect (OSTI)

    Yoo, Hye-Min; Lee, Seul-Yi [Korea CCS R and D Center, Korea Institute of Energy Research, 152 Gajeongro, Yuseoung-gu, Daejeon 305-343 (Korea, Republic of); Department of Chemistry, Inha University, 100 Inharo, Nam-gu, Incheon 402-751 (Korea, Republic of); Park, Soo-Jin, E-mail: sjpark@inha.ac.kr [Korea CCS R and D Center, Korea Institute of Energy Research, 152 Gajeongro, Yuseoung-gu, Daejeon 305-343 (Korea, Republic of); Department of Chemistry, Inha University, 100 Inharo, Nam-gu, Incheon 402-751 (Korea, Republic of)

    2013-01-15

    Ordered nanoporous carbons (ONCs) were prepared using a soft-templating method. The prepared ONCs materials were subjected to a controlled carbonization temperature over the temperature range, 700-1000 Degree-Sign C, to increase the specific surface area and total pore volume of ordered nanoporous carbon followed by carbonization of the phenolic resin. ONCs materials synthesized at various carbonization temperatures were used as adsorbents to improve the CO{sub 2} adsorption efficiency. The surface properties of the ONCs materials were examined by X-ray photoelectron spectroscopy. The structural properties of the ONCs materials were analyzed by X-ray diffraction. The textural properties of the ONCs materials were examined using the N{sub 2}/77 K adsorption isotherms according to the Brunauer-Emmett-Teller equation. The CO{sub 2} adsorption capacity was measured by CO{sub 2} isothermal adsorption at 298 K/30 bar and 298 K/1 bar. The carbonization temperature was found to have a major effect on the CO{sub 2} adsorption capacity, resulting from the specific surface area and total pore volumes of the ONCs materials. - Graphical abstract: This schematic diagram described synthesis of ONCs. Highlights: Black-Right-Pointing-Pointer ONCs materials can be prepared readily using the direct-triblock-copolymer-templating method. Black-Right-Pointing-Pointer The distributions show that prominent development can be observed around the micro-pore region. Black-Right-Pointing-Pointer The soft-templating method provides opportunities for controlling the pore structure of ONCs. Black-Right-Pointing-Pointer From thermal power plants for CO2 capture by adsorption technology, is a new direction.

  19. Synthesis and structural characterization of Al{sub 7}C{sub 3}N{sub 3}-homeotypic aluminum silicon oxycarbonitride, (Al{sub 7-x}Si{sub x})(O{sub y}C{sub z}N{sub 6-y-z}) (x{approx}1.2, y{approx}1.0 and z{approx}3.5)

    SciTech Connect (OSTI)

    Urushihara, Daisuke; Kaga, Motoaki; Asaka, Toru; Nakano, Hiromi; Fukuda, Koichiro

    2011-08-15

    A new aluminum silicon oxycarbonitride, (Al{sub 5.8}Si{sub 1.2})(O{sub 1.0}C{sub 3.5}N{sub 1.5}), has been synthesized and characterized by X-ray powder diffraction (XRPD), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX) and electron energy loss spectroscopy (EELS). The title compound is hexagonal with space group P6{sub 3}/mmc and unit-cell dimensions a=0.322508(4) nm, c=3.17193(4) nm and V=0.285717(6) nm{sup 3}. The atom ratios of Al:Si and those of O:C:N were, respectively, determined by EDX and EELS. The initial structural model was successfully derived from the XRPD data by the direct methods and further refined by the Rietveld method. The crystal is most probably composed of four types of domains with nearly the same fraction, each of which is isotypic to Al{sub 7}C{sub 3}N{sub 3} with space group P6{sub 3}mc. The existence of another new oxycarbonitride (Al{sub 6.6}Si{sub 1.4})(O{sub 0.7}C{sub 4.3}N{sub 2.0}), which must be homeotypic to Al{sub 8}C{sub 3}N{sub 4}, has been also demonstrated by XRPD and TEM. - Graphical abstract: A new oxycarbonitride discovered in the Al-Si-O-C-N system, (Al{sub 7-x}Si{sub x})(O{sub y}C{sub z}N{sub 6-y-z}) (x{approx}1.2, y{approx}1.0 and z{approx}3.5). The crystal is composed of four types of domains (I, II, III and IV), and hence the structure is represented by a split-atom model. Individual crystal structures can be regarded as layered structures, which consist of A-type [(Al, Si){sub 4}(O, C, N){sub 4}] unit layers and B-type [(Al, Si)(O, C, N){sub 2}] single layers. Highlights: > (Al{sub 5.8}Si{sub 1.2})(O{sub 1.0}C{sub 3.5}N{sub 1.5}) as a new aluminum silicon oxycarbonitride. > Crystal structure is determined and represented by a split-atom model. > Existence of another new oxycarbonitride (Al{sub 6.6}Si{sub 1.4})(O{sub 0.7}C{sub 4.3}N{sub 2.0}) is demonstrated. > Both new materials are formed by oxidation and nitridation of (Al, Si){sub 6}(O, C){sub 5}.

  20. Diffused phase transitions in Pb(Zr{sub 0.65}Ti{sub 0.35})O{sub 3}-Pb(Fe{sub 2/3}W{sub 1/3})O{sub 3} multiferroics

    SciTech Connect (OSTI)

    Tirupathi, Patri; Kumar, Nawnit; Pastor, Mukul Pandey, A. C.; Choudhary, R. N. P.

    2015-02-21

    The solid solutions of (1?x)Pb(Zr{sub 0.65}Ti{sub 0.35})O{sub 3}-xPb(Fe{sub 2/3}W{sub 1/3})O{sub 3} in different ratios were fabricated by a high-temperature solid-state reaction method using high-purity oxides for possible multi-ferroic applications. Structural analysis using x-ray diffraction powder patterns of the system by Rietveld refinement method exhibits the formation of rhombohedral phase with R3c space group. Detailed studies of dielectric permittivity as a function of temperature of the systems show that the frequency independent dielectric maximum temperature shifts toward room temperature on increasing x. In addition to this, the degree of diffuseness of the permittivity anomaly is more pronounced for higher content of Pb(Fe{sub 2/3}W{sub 1/3})O{sub 3}, implying the existence of a composition-induced diffuse phase transition for the limited range of compositional ratios. Detailed impedance spectroscopy analysis shows the contributions of grain, grain boundary, and interfacial polarizations in the resistive characteristics and conduction mechanism of the materials. The weak ferromagnetic and saturated ferroelectric loops indicate that system with x?=?0.1, 0.2 have good multiferroic characteristics, and may be useful for future spintronic devices.

  1. Hydrothermal synthesis and crystal structure of a new inorganic/organic hybrid of scandium sulfate: (H{sub 2}en)Sc{sub 2}(SO{sub 4}){sub 4}.(H{sub 2}O){sub 0.72}

    SciTech Connect (OSTI)

    Lu Jianjiang [Materials Science Division, Argonne National Laboratory, 9700 S Cass Avenue, Argonne, IL 60439 (United States)]. E-mail: j.lu@anl.gov; Schlueter, John A. [Materials Science Division, Argonne National Laboratory, 9700 S Cass Avenue, Argonne, IL 60439 (United States); Geiser, Urs [Materials Science Division, Argonne National Laboratory, 9700 S Cass Avenue, Argonne, IL 60439 (United States)

    2006-05-15

    The first organically templated layered structure of scandium sulfate, (H{sub 2}en)Sc{sub 2}(SO{sub 4}){sub 4}.(H{sub 2}O){sub 0.72}, (en=ethylenediamine) was synthesized by a hydrothermal method and characterized by single crystal X-ray diffraction. In the title compound, scandium ions are bridged by sulfate groups with a ratio of 1:2 into a 4{sub 3}{sup 6} layer structure. These layers are parallel packed and separated from each other by ethylenediammonium dications and water molecules. The title compound crystallizes in the monoclinic space group P2/c, with cell parameters a=8.5966(13)A, b=5.1068(8)A, c=18.847(3)A, {beta}=91.210(3){sup o}, V=827.2(2)A{sup 3} and Z=2. Refinement gave R{sub 1}[I>2{sigma}(I)]=0.0354 and wR{sub 2}[I>2{sigma}(I)]=0.0878. Thermogravimetric analysis indicates that this material is thermally stable to above 400 deg. C.

  2. Regional Test Centers (RTCs)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    has established five Regional Test Centers (RTCs) across the United States to independently validate the performance and reliability of photovoltaic (PV) systems in different...

  3. Synthesis, crystal and electronic structure, and physical properties of the new lanthanum copper telluride La{sub 3}Cu{sub 5}Te{sub 7}

    SciTech Connect (OSTI)

    Zelinska, Mariya; Assoud, Abdeljalil [Department of Chemistry, University of Waterloo, Waterloo, ON, Canada N2L 3G1 (Canada); Kleinke, Holger, E-mail: kleinke@uwaterloo.c [Department of Chemistry, University of Waterloo, Waterloo, ON, Canada N2L 3G1 (Canada)

    2011-03-15

    The new lanthanum copper telluride La{sub 3}Cu{sub 5-x}Te{sub 7} has been obtained by annealing the elements at 1073 K. Single-crystal X-ray diffraction studies revealed that the title compound crystallizes in a new structure type, space group Pnma (no. 62) with lattice dimensions of a=8.2326(3) A, b=25.9466(9) A, c=7.3402(3) A, V=1567.9(1) A{sup 3}, Z=4 for La{sub 3}Cu{sub 4.86(4)}Te{sub 7}. The structure of La{sub 3}Cu{sub 5-x}Te{sub 7} is remarkably complex. The Cu and Te atoms build up a three-dimensional covalent network. The coordination polyhedra include trigonal LaTe{sub 6} prisms, capped trigonal LaTe{sub 7} prisms, CuTe{sub 4} tetrahedra, and CuTe{sub 3} pyramids. All Cu sites exhibit deficiencies of various extents. Electrical property measurements on a sintered pellet of La{sub 3}Cu{sub 4.86}Te{sub 7} indicate that it is a p-type semiconductor in accordance with the electronic structure calculations. -- Graphical abstract: Oligomeric unit comprising interconnected CuTe{sub 3} pyramids and CuTe{sub 4} tetrahedra. Display Omitted Research highlights: {yields} La{sub 3}Cu{sub 5-x}Te{sub 7} adopts a new structure type. {yields} All Cu sites exhibit deficiencies of various extents. {yields} The coordination polyhedra include trigonal LaTe{sub 6} prisms, capped trigonal LaTe{sub 7} prisms, CuTe{sub 4} tetrahedra and CuTe{sub 3} pyramids. {yields} La{sub 3}Cu{sub 5-x}Te{sub 7} is a p-type semiconductor.

  4. Microstructure and hydriding studies of AB/sub 5/ hydrogen storage compounds. Final report

    SciTech Connect (OSTI)

    Goodell, P.D.; Sandrock, G.D.; Huston, E.L.

    1980-01-01

    New data on the microstructure, pressure-composition-temperature, and absorption/desorption kinetics of AB/sub 5/ metal hydrides are presented. The most significant result to emerge from the investigation is that many of the AB/sub 5/ metal hydrides, especially the LaNi/sub 5/ related materials, show instantaneous absorption and desorption response in proportion to the amount of cooling or heating which is provided. Eight categories of materials were studied: reference alloys (LaNi/sub 5/, LaNi/sub 4/ /sub 9/Al/sub 0/ /sub 1/, LaNi/sub 3/Co/sub 2/); Ni second phase particles (LaNi/sub 5/ /sub 67/, LaNi/sub 7/, LaNi/sub 11/ /sub 3/); eutectoid microstructure (SmCo/sub 5/); other second phases (LaNi/sub 3/ /sub 8/Fe/sub 1/ /sub 2/, LaNi/sub 3/ /sub 5/Cr/sub 1/ /sub 5/, LaNi/sub 4/Cr, LaNi/sub 4/Si; LaNi/sub 4/Sn, MNi/sub 4/Sn, MNi/sub 4/ /sub 3/Al/sub 0/ /sub 7/); substitutional elements (LaNi/sub 4/Cu, LaNi/sub 4/ /sub 5/Pd/sub 0/ /sub 5/, LaNi/sub 4/ /sub 7/Sn/sub 0/ /sub 3/, LaNi/sub 4/ /sub 8/C/sub 0/ /sub 2/, MNi/sub 4/ /sub 3/Mn/sub 0/ /sub 7/); surface active elements (LaNi/sub 4/ /sub 8/B/sub 0/ /sub 2/, LaNi/sub 4/ /sub 9/S/sub 0/ /sub 1/, LaNi/sub 4/ /sub 9/Se/sub 0/ /sub 1/); large diameter atom substitutions (Mg/sub 0/ /sub 1/La/sub 0/ /sub 9/Ni/sub 5/, Ca/sub 0/ /sub 2/La/sub 0/ /sub 8/Ni/sub 5/, Sr/sub 0/ /sub 2/La/sub 0/ /sub 8/Ni/sub 5/, Ba/sub 0/ /sub 2/La/sub 0/ /sub 8/Ni/sub 5/); other compositions (LaNi/sub 3/); and Pd plating (electroless plated samples and mechanically alloyed specimens).

  5. Method for synthesizing fine-grained phosphor powders of the type (RE.sub.1- Ln.sub.x)(P.sub.1-y V.sub.y)O.sub.4

    DOE Patents [OSTI]

    Phillips, Mark L. F. (83 Lagarto Rd., Tijeras, NM 87059)

    1998-01-01

    A method for generating well-crystallized photo- and cathodoluminescent oxide phosphor powders. The method of this invention uses hydrothermal synthesis and annealing to produce nearly monosized (RE.sub.1-x Ln.sub.x)(P.sub.1-y V.sub.y)O.sub.4 (Ln.dbd.Ce.fwdarw.Lu) phosphor grains with crystallite sizes from 0.04 to 5 .mu.m. Such phosphors find application in cathode-ray tube, flat-panel, and projection displays.

  6. A highly coercive carbon nanotube coated with Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} nanocrystals synthesized by chemical precipitation-hydrothermal process

    SciTech Connect (OSTI)

    Cao Huiqun; Zhu Meifang Li Yaogang; Liu Jianhong; Ni Zhuo; Qin Zongyi

    2007-11-15

    Novel magnetic composites (Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4}-MWCNTs) of multi-walled carbon nanotubes (MWCNTs) coated with Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} nanocrystals were synthesized by chemical precipitation-hydrothermal process. The composites were characterized by X-ray powder diffractometer (XRD), X-ray photoelectron spectrometer (XPS), Fourier transform infrared spectroscopy (FTIR), Moessbauer spectroscopy (MS), transmission electron microscopy (TEM), and selected area electron diffraction (SAED), etc. A temperature of about 200 deg. C was identified to be an appropriate hydrothermal condition to obtain Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4}-MWCNTs, being lower than the synthesis temperature of a single-phase Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} nanocrystals. The sizes of Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} in the composites were smaller than those of Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} nanocrystals in single phase. The composites exhibited more superparamagnetic than Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} nanocrystals in their relaxation behaviors. The magnetic properties measured by a vibrating sample magnetometer showed that the composites had a high coercive field of 386.0 Oe at room temperature, higher than those of MWCNT and Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} nanocrystals. - Graphical abstract: Novel magnetic composites (Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4}-MWCNTs) of multi-walled carbon nanotubes (MWCNTs) coated with Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} nanocrystals were synthesized by chemical precipitation-hydrothermal process. The composites had a high coercive field of 386.0 Oe, higher than those of MWCNT and Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} nanocrystals.

  7. Strong electron correlation in UO{sub 2}{sup ?}: A photoelectron spectroscopy and relativistic quantum chemistry study

    SciTech Connect (OSTI)

    Li, Wei-Li; Jian, Tian; Lopez, Gary V.; Wang, Lai-Sheng, E-mail: lai-sheng-wang@brown.edu [Department of Chemistry, Brown University, Providence, Rhode Island 02912 (United States)] [Department of Chemistry, Brown University, Providence, Rhode Island 02912 (United States); Su, Jing [Department of Chemistry and Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Tsinghua University, Beijing 100084 (China) [Department of Chemistry and Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Tsinghua University, Beijing 100084 (China); Division of Nuclear Materials Science and Engineering, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China and Key Laboratory of Nuclear Radiation and Nuclear Energy Technology, Chinese Academy of Sciences, Shanghai 201800 (China); Hu, Han-Shi; Cao, Guo-Jin; Li, Jun, E-mail: junli@tsinghua.edu.cn [Department of Chemistry and Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Tsinghua University, Beijing 100084 (China)] [Department of Chemistry and Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Tsinghua University, Beijing 100084 (China)

    2014-03-07

    The electronic structures of actinide systems are extremely complicated and pose considerable challenges both experimentally and theoretically because of significant electron correlation and relativistic effects. Here we report an investigation of the electronic structure and chemical bonding of uranium dioxides, UO{sub 2}{sup ?} and UO{sub 2}, using photoelectron spectroscopy and relativistic quantum chemistry. The electron affinity of UO{sub 2} is measured to be 1.159(20) eV. Intense detachment bands are observed from the UO{sub 2}{sup ?} low-lying (7s?{sub g}){sup 2}(5f?{sub u}){sup 1} orbitals and the more deeply bound O2p-based molecular orbitals which are separated by a large energy gap from the U-based orbitals. Surprisingly, numerous weak photodetachment transitions are observed in the gap region due to extensive two-electron transitions, suggesting strong electron correlations among the (7s?{sub g}){sup 2}(5f?{sub u}){sup 1} electrons in UO{sub 2}{sup ?} and the (7s?{sub g}){sup 1}(5f?{sub u}){sup 1} electrons in UO{sub 2}. These observations are interpreted using multi-reference ab initio calculations with inclusion of spin-orbit coupling. The strong electron correlations and spin-orbit couplings generate orders-of-magnitude more detachment transitions from UO{sub 2}{sup ?} than expected on the basis of the Koopmans’ theorem. The current experimental data on UO{sub 2}{sup ?} provide a long-sought opportunity to arbitrating various relativistic quantum chemistry methods aimed at handling systems with strong electron correlations.

  8. Magnetic properties of Co{sub 2?x}TM{sub x}C and Co{sub 3?x}TM{sub x}C nanoparticles

    SciTech Connect (OSTI)

    Qian, Meichun; Khanna, Shiv N., E-mail: snkhanna@vcu.edu [Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284 (United States)

    2013-12-28

    Using synthetic chemical approaches, it is now possible to synthesize transition metal carbides nanoparticles with morphology, where the transition metal layers are embedded with intervening layers of carbon atoms. A composite material consisting of Co{sub 2}C and Co{sub 3}C nanoparticles has been found to exhibit unusually large coercivity and energy product. Here, we demonstrate that the magnetic moments and the anisotropy can be further enhanced by using a combination of Co and other transition metals (TM). Our studies are based on mixed nanoparticles Co{sub 2?x}TM{sub x}C and Co{sub 3?x}TM{sub x}C, in which selected Co sites are replaced with 3d transition elements Cr, Mn, and Fe. The studies indicate that the replacement of Co by Fe results in an increase of both the magnetic moment and the magnetic anisotropy. In particular, CoFe{sub 2}C is shown to have an average spin moment of 2.56??{sub B} and a magnetic anisotropy of 0.353?meV/formula unit compared to 1.67??{sub B} and 0.206?meV/formula unit for the Co{sub 3}C. Detailed examination of the electronic structure shows that the limited hybridization of carbon p-states with transition metal d-states drives the larger anisotropy.

  9. Role of pressure in understanding the anomalous superconductivity in europium (molybdenum)/sub 6/(sulfur)/sub 8/ and (TMTSF)/sub 2/FSO/sub 3/

    SciTech Connect (OSTI)

    Wolf, S.A.; Huang, C.Y.; Lacoe, R.C.; Chaikin, P.M.; Fuller, W.W.; Luo, H.L.; Wudl, F.

    1983-01-01

    Both the Chevrel phase compound EuMo/sub 6/S/sub 8/ and the organic material, (TMTSF)/sub 2/FSO/sub 3/ are superconducting only under moderate pressure. In both instances the absence of superconductivity at ambient pressure is directly attributed to a low temperature structural distortion that introduces a gap over all or part of the Fermi surface. The role of pressure is to suppress the transition and thus allow the electrons to condense into the superconducting state. In EuMo/sub 6/S/sub 8/, details of the pressure dependence of both the structural and superconducting transition have been explained on the basis of a competition between a charge density wave-type state and superconductivity. In the case of (TMTSF)/sub 2/FSO/sub 3/ an anion ordering giving rise to a metal-insulator transition is responsible for suppressing superconductivity. The critical magnetic fields of EuMo/sub 6/S/sub 8/ are extremely anomalous and are related to the magnetism of the Eu as well as the structure of the compound.

  10. Magnetisation studies of phase co-existence in Gd{sub 1-x}Ca{sub x}BaCo{sub 2}O{sub 5.5}

    SciTech Connect (OSTI)

    Thirumurugan, N. [Condensed Matter Physics Division, Indira Gandhi Centre for Atomic Research, Kalpakkam (India)] [Condensed Matter Physics Division, Indira Gandhi Centre for Atomic Research, Kalpakkam (India); Bharathi, A., E-mail: bharathi@igcar.gov.in [Condensed Matter Physics Division, Indira Gandhi Centre for Atomic Research, Kalpakkam (India); Arulraj, A.; Sundar, C.S. [Condensed Matter Physics Division, Indira Gandhi Centre for Atomic Research, Kalpakkam (India)] [Condensed Matter Physics Division, Indira Gandhi Centre for Atomic Research, Kalpakkam (India)

    2012-04-15

    Highlights: Black-Right-Pointing-Pointer The series Gd{sub 1-x}Ca{sub x}BaCo{sub 2}O{sub 5.5} was synthesised by solid state reaction. Black-Right-Pointing-Pointer Magnetisation studies were carried out in the 4-300 K temperature range in magnetic fields upto 16 Tesla. Black-Right-Pointing-Pointer Results were used to formulate the T versus Ca fraction, phase diagram. Black-Right-Pointing-Pointer Evidence for Magnet-electronic phase separation is shown for the first time in the compound. -- Abstract: Magnetic properties of hole doped, oxygen deficient double perovskite compounds, Gd{sub 1-x}Ca{sub x}BaCo{sub 2}O{sub 5.5}, have been investigated. Ferromagnetic transition temperatures increase and the anti-ferromagnetic transition temperatures decrease with Ca substitution leading to stabilisation of ferromagnetisim for x {>=} 0.05. A detailed study of the ferromagnetic phase indicates the presence of double hysterisis loops for Ca fractions, 0.05 {<=} x {<=} 0.2 in the 50-200 K temperature range, suggestive of the co-existence of two ferromagnetic phases with different co-ercivities. Based on the magnetisation and transport measurements a phase diagram is proposed for Ca doped GdBaCo{sub 2}O{sub 5.5}.

  11. Preparation and thermophysical properties of (Sm{sub 1?x}Er{sub x}){sub 2}Ce{sub 2}O{sub 7} oxides for thermal barrier coatings

    SciTech Connect (OSTI)

    Xiaoge, Chen; Shusen, Yang; Hongsong, Zhang; Gang, Li; Zhenjun, Li.; Bo, Ren; Xudan, Dang; Haoming, Zhang; An, Tang

    2014-03-01

    Graphical abstract: - Highlights: • These ceramic materials with fluorite structure were synthesized. • Defect points lead to their lower thermal conductivities. • The lower ionic radius of Er{sup 3+} ion leads to the reduction of thermal expansion coefficient of (Sm{sub 1?x}Er{sub x}){sub 2}Ce{sub 2}O{sub 7} oxides. - Abstract: (Sm{sub 1?x}Er{sub x}){sub 2}Ce{sub 2}O{sub 7} ceramics were synthesized by sol–gel method and sintered at 1600 °C for 10 h in air. The influence of Er{sub 2}O{sub 3}-substitution on the phase structure and thermophysical properties of Sm{sub 2}Ce{sub 2}O{sub 7} was investigated. The phase structures of these ceramics were identified by X-ray diffraction showing that all synthesized ceramics have fluorite-type structure. The measurements for thermophysical properties of these ceramics show that their thermal conductivities and thermal expansion coefficients remarkably decreased through Er-substitution. However, the thermal expansion coefficients were higher than that of YSZ and their thermal conductivities were much lower than that of 8YSZ. The excellent thermophysical property implies that these solid solutions are potential materials for the ceramics layer in thermal barrier coatings.

  12. Diffusion of CO{sub 2} on Rutile TiO{sub 2}(110) Surface

    SciTech Connect (OSTI)

    Lee, Junseok; Sorescu, Dan C.; Deng, Xingyi; Jordan, Kenneth D.

    2011-12-15

    The diffusion of CO{sub 2} molecules on a reduced rutile TiO{sub 2}(110)-(1×1) surface has been investigated using scanning tunneling microscopy (STM) and density functional theory (DFT) calculations. The STM feature associated with a CO{sub 2} molecule at an oxygen vacancy (V{sub O}) becomes increasingly streaky with increasing temperature, indicating thermally activated CO{sub 2} diffusion from the V{sub O} site. From temperature-dependent tunneling current measurements, the barrier for diffusion of CO{sub 2} from the V{sub O} site is estimated to be 3.31 ± 0.23 kcal/mol. The corresponding value from the DFT calculations is 3.80 kcal/mol. In addition, the DFT calculations give a barrier for diffusion of CO{sub 2} along Ti rows of only 1.33 kcal/mol.

  13. Synthesis, crystal structure and photoluminescence of a new Eu-doped Sr containing sialon (Sr{sub 0.94}Eu{sub 0.06})(Al{sub 0.3}Si{sub 0.7}){sub 4}(N{sub 0.8}O{sub 0.2}){sub 6}

    SciTech Connect (OSTI)

    Yamane, Hisanori; Shimooka, Satoshi; Uheda, Kyota

    2012-06-15

    Colorless transparent platelet single crystals of a novel Eu{sup 2+}-doped strontium silicon aluminum oxynitride, (Sr{sub 0.94}Eu{sub 0.06})(Al{sub 0.3}Si{sub 0.7}){sub 4}(N{sub 0.8}O{sub 0.2}){sub 6}, were prepared at 1800 Degree-Sign C and 0.92 MPa of N{sub 2}. Fundamental reflections of electron and X-ray diffraction of the crystals were indexed with a face-centered orthorhombic unit cell (a=5.8061(5) A, b=37.762(3) A, c=9.5936(9) A). Diffuse streaks elongated in the b-axis direction were observed around the fundamental reflections hkl with h=2n+1 of the electron and X-ray diffraction, indicating stacking faults of (0 1 0)[1 0 0]/2. A crystal structure model without the stacking faults was obtained using the X-ray diffraction data of the fundamental reflections with the space group Fdd2. A SiN{sub 4}-tetrahedron double layer of [SiN{sub 2}]{sub 2} and a Sr/Eu double layer of [(Sr{sub 0.94}Eu{sub 0.06})Al{sub 1.2}Si{sub 0.8}N{sub 0.8} O{sub 1.2}]{sub 2} are stacked alternately along the b-axis direction. The title compound showed an emission with a peak wavelength of 490 nm under 334 nm excitation at room temperature. - Graphical abstract: Single crystals of a novel Eu{sup 2+}-doped strontium silicon aluminum oxynitride, (Sr{sub 0.94}Eu{sub 0.06})(Al{sub 0.3}Si{sub 0.7}){sub 4}(N{sub 0.8}O{sub 0.2}){sub 6}, having stacking faults on the (0 1 0) plane of an orthorhombic cell, were prepared at 1800 Degree-Sign C and 0.92 MPa of N{sub 2}. The compound showed emission with a peak wavelength of 490 nm under 334 nm excitation at room temperature. Highlights: Black-Right-Pointing-Pointer A new compound Eu{sup 2+}-doped (Sr{sub 0.94}Eu{sub 0.06})(Al{sub 0.3}Si{sub 0.7}){sub 4}(N{sub 0.8}O{sub 0.2}){sub 6} was prepared. Black-Right-Pointing-Pointer Stacking faults in the compound were clarified by electron and X-ray diffraction. Black-Right-Pointing-Pointer A basic crystal structure model was obtained based on the X-ray diffraction data. Black-Right-Pointing-Pointer An emission of 490 nm under 334 nm excitation at room temperature was observed.

  14. Phase Diagram and Spin Hamiltonian of Weakly-coupled Anisotropic S=1/2 Chains in CuCl<sub>2sub>.2((CD<sub>3sub>)>2sub>SO)

    SciTech Connect (OSTI)

    Chen, Y. [Johns Hopkins University; Stone, Matthew B [ORNL; Kenzelmann, M. [Johns Hopkins University; Batista, C. D. [Los Alamos National Laboratory (LANL); Reich, D. H. [Johns Hopkins University; Broholm, C. L. [Brookhaven National Laboratory (BNL)

    2007-01-01

    Field-dependent specific heat and neutron scattering measurements were used to explore the antiferromagnetic S=(1/2) chain compound CuCl{sub 2}{center_dot}2((CD{sub 3}){sub 2}SO). At zero field the system acquires magnetic long-range order below T{sub N}=0.93 K with an ordered moment of 0.44{micro}{sub B}. An external field along the b axis strengthens the zero-field magnetic order, while fields along the a and c axes lead to a collapse of the exchange stabilized order at {micro}{sub 0}H{sub c}=6 T and {micro}{sub 0}H{sub c}=4 T (extrapolated to zero temperature) and the formation of an energy gap in the excitation spectrum. We relate the field-induced gap to the presence of a staggered g-tensor and Dzyaloshinskii-Moriya interactions, which lead to effective staggered fields for magnetic fields applied along the a and c axes. Competition between anisotropy, interchain interactions, and staggered fields leads to a succession of three phases as a function of field applied along the c axis. For fields greater than {micro}{sub 0}H{sub c}, we find a magnetic structure that reflects the symmetry of the staggered fields. The critical exponent, beta, of the temperature driven phase transitions are indistinguishable from those of the three-dimensional Heisenberg magnet, while measurements for transitions driven by quantum fluctuations produce larger values of beta.

  15. Photodissociation of (SO{sub 2}?XH) Van der Waals complexes and clusters (XH = C{sub 2}H{sub 2}, C{sub 2}H{sub 4}, C{sub 2}H{sub 6}) excited at 32?040–32?090 cm{sup ?1} with formation of HSO{sub 2} and X

    SciTech Connect (OSTI)

    Makarov, Vladimir I.; Kochubei, Sergei A.; Khmelinskii, Igor

    2014-02-07

    We studied photodecomposition dynamics of (SO{sub 2}?XH) Van der Waals’ (VdW) complexes and clusters in gas phase, with X = C{sub 2}H, C{sub 2}H{sub 3}, and C{sub 2}H{sub 5}. SO{sub 2} was excited by frequency-doubled radiation of a tunable dye laser and resonance-enhanced multiphoton ionization was used to detect the C{sub 2}H (m/z 25), C{sub 2}H{sub 3} (m/z 27), and C{sub 2}H{sub 5} (m/z 29) ions by time-of-flight mass spectroscopy. Spectra obtained at higher nozzle pressures (P{sub 0} > 2.5 atm) indicate formation of clusters. Detailed studies of the VdW complex structure were carried out by analyzing the rotational structure of the respective action spectra. We also performed ab initio theoretical analysis of structures of the VdW complexes and transitional states leading to photodecomposition. We find that the structure of the transition state is significantly different as compared to the equilibrium ground-state structure of the respective complex. The photodecomposition mechanism depends on the hydrocarbon molecule bound to SO{sub 2}.

  16. CO<sub>2sub> induced phase transitions in diamine-appended metal–organic frameworks

    SciTech Connect (OSTI)

    Vlaisavljevich, Bess; Odoh, Samuel O.; Schnell, Sondre K.; Dzubak, Allison L.; Lee, Kyuho; Planas, Nora; Neaton, Jeffrey B.; Gagliardi, Laura; Smit, Berend

    2015-01-01

    Using a combination of density functional theory and lattice models, we study the effect of CO<sub>2sub> adsorption in an amine functionalized metal–organic framework. These materials exhibit a step in the adsorption isotherm indicative of a phase change. The pressure at which this step occurs is not only temperature dependent but is also metal center dependent. Likewise, the heats of adsorption vary depending on the metal center. Herein we demonstrate via quantum chemical calculations that the amines should not be considered firmly anchored to the framework and we explore the mechanism for CO<sub>2sub> adsorption. An ammonium carbamate species is formed via the insertion of CO<sub>2sub> into the M–N<sub>amine> bonds. Furthermore, we translate the quantum chemical results into isotherms using a coarse grained Monte Carlo simulation technique and show that this adsorption mechanism can explain the characteristic step observed in the experimental isotherm while a previously proposed mechanism cannot. Furthermore, metal analogues have been explored and the CO<sub>2sub> binding energies show a strong metal dependence corresponding to the M–N<sub>amine> bond strength. We show that this difference can be exploited to tune the pressure at which the step in the isotherm occurs. Additionally, the mmen–Ni<sub>2sub>(dobpdc) framework shows Langmuir like behavior, and our simulations show how this can be explained by competitive adsorption between the new model and a previously proposed model.

  17. On the peculiar properties of triangular-chain EuCr{sub 3}(BO{sub 3}){sub 4} antiferromagnet

    SciTech Connect (OSTI)

    Gondek, ?.; Szytu?a, A.; Przewo?nik, J.; ?ukrowski, J.; Prokhorov, A.; Chernush, L.; Zubov, E.; Dyakonov, V.; Tyvanchuk, Yu.

    2014-02-15

    In this paper we report studies on EuCr{sub 3}(BO{sub 3}){sub 4} compound, that is a member of newly discovered family of huntite-related specimens for non-linear optics. For the first time, the uncommon temperature dependence of the EuCr{sub 3}(BO{sub 3}){sub 4} lattice parameters is reported. Additionally, the magnetism of this compound is extremely interesting. Namely, a possible interplay in between potentially magnetic rare-earth ions and 3d metal stacked within quasi-1D chain that can lead to a great variety of magnetic behaviour. Indeed, in our studies we have found 3D-long range ordering with metamagnetic behaviour, while at higher temperature the magnetic chains become uncoupled. - Graphical abstract: Torsion-like vibrations are the key to understand negative thermal expansion along the a-axis. Display Omitted - Highlights: • EuCr{sub 3}(BO{sub 3}){sub 4} is a peculiar triangular-chain antiferromagnet. • Rare earth sublattice is non-magnetic with Eu{sup 3+} configuration. • Cr{sup 3+} magnetic moments show 1-D behaviour along with spin fluctuations. • Torsion vibrations of Cr triangular tubes lead to anomalous expansion of unit cell.

  18. Electron interactions and Dirac fermions in graphene-Ge{sub 2}Sb{sub 2}Te{sub 5} superlattices

    SciTech Connect (OSTI)

    Sa, Baisheng [College of Materials, and Collaborative Innovation Center of Chemistry for Energy Materials, Xiamen University, Xiamen 361005 (China); Sun, Zhimei, E-mail: zmsun@buaa.edu.cn [School of Materials Science and Engineering, and Center for Integrated Computational Materials Engineering, International Research Institute for Multidisciplinary Science, Beihang University, Beijing 100191 (China)

    2014-06-21

    Graphene based superlattices have been attracted worldwide interest due to the combined properties of the graphene Dirac cone feature and all kinds of advanced functional materials. In this work, we proposed a novel series of graphene-Ge{sub 2}Sb{sub 2}Te{sub 5} superlattices based on the density functional theory calculations. We demonstrated the stability in terms of energy and lattice dynamics for such kind of artificial materials. The analysis of the electronic structures unravels the gap opening nature at Dirac cone of the insert graphene layer. The Dirac fermions in the graphene layers are strongly affected by the electron spin orbital coupling in the Ge{sub 2}Sb{sub 2}Te{sub 5} layers. The present results show the possible application in phase-change data storage of such kind of superlattice materials, where the Ge{sub 2}Sb{sub 2}Te{sub 5} layers exhibit as the phase-change data storage media and the graphene layer works as the electrode, probe, and heat conductor.

  19. The multiferroic properties of polycrystalline Bi{sub 1?x}Y{sub x}FeO{sub 3} films

    SciTech Connect (OSTI)

    Sheng, Yan [Department of Physics, Southeast University, Nanjing 211189, China and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 210096 (China); Rui, Wenbin; Du, Jun, E-mail: jdu@nju.edu.cn, E-mail: xuqingyu@seu.edu.cn [National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China); Qiu, Xiangbiao [Department of Materials Science and Engineering, Nanjing University, Nanjing 210008 (China); Zhou, Shengqiang [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, P.O. Box 510119, Dresden 01314 (Germany); Xu, Qingyu, E-mail: jdu@nju.edu.cn, E-mail: xuqingyu@seu.edu.cn [Department of Physics, Southeast University, Nanjing 211189, China and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 210096 (China); National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China)

    2014-05-07

    Polycrystalline Bi{sub 1?x}Y{sub x}FeO{sub 3} films with varying x from 0 to 0.30 were prepared by pulsed laser deposition on surface oxidized Si (100) substrates with LaNiO{sub 3} as buffer layer. The influence of Y doping on the structure, ferroelectric properties, and exchange bias have been systematically investigated. X-ray diffraction and Raman spectroscopy studies revealed the structural transition from rhombohedral R3c to orthorhombic Pn2{sub 1}a with increasing x above 0.10. The leakage current density of BiFeO{sub 3} has been effectively suppressed by Y doping, and well saturated P–E loops have been observed in Bi{sub 1?x}Y{sub x}FeO{sub 3} (0.01???x???0.07). Exchange bias field with a 3.6?nm thick NiFe layer increases with increasing x to 0.01, then decreases with further increasing x.

  20. Synthesis and structural characterization of a new rubidium borosulfate, Rb{sub 5}BS{sub 4}O{sub 16}

    SciTech Connect (OSTI)

    Dong, Lingyun; Pan, Shilie; Wang, Ying; Yu, Hongwei; Lin, Xiaoxia; Han, Shujuan

    2015-03-15

    Highlights: • Rb{sub 5}BS{sub 4}O{sub 16} has been synthesized using (NH{sub 4}){sub 2}SO{sub 4} as a source of sulfate ions for the first time. • Zero-dimensional anion groups, [B(SO{sub 4}){sub 4}]{sup 5?}, exist in the title compound. • Spectral properties and thermal analysis of Rb{sub 5}BS{sub 4}O{sub 16} were reported. - Abstract: A new rubidium borosulfate, Rb{sub 5}BS{sub 4}O{sub 16}, has been synthesized using (NH{sub 4}){sub 2}SO{sub 4} as a source of sulfate ions for the first time. The compound crystallizes in the space group P4{sub 3}2{sub 1}2 (No. 96) of the tetragonal system with a = 10.148(4) Å, c = 16.689(14) Å, V = 1718.8(17) Å{sup 3}, and Z = 4. Zero-dimensional anion groups, [B(SO{sub 4}){sub 4}]{sup 5?}, a central BO{sub 4} tetrahedron sharing all its four vertices with neighboring sulfate tetrahedra, exist in the title compound, and then the rubidium atoms are situated in the voids of the resulting structure. The IR spectrum confirms the presence of BO{sub 4} and SO{sub 4} units. The UV–vis-NIR diffuse reflectance spectrum exhibits a band gap of about 3.99 eV. The TG-DSC analysis suggests that Rb{sub 5}BS{sub 4}O{sub 16} is an incongruent melting compound.

  1. BaZn{sub 2}Si{sub 2}O{sub 7} and the solid solution series BaZn{sub 2?x}Co{sub x}Si{sub 2}O{sub 7} (0

    SciTech Connect (OSTI)

    Kerstan, Marita; Thieme, Christian; Grosch, Matthias; Müller, Matthias; Rüssel, Christian, E-mail: ccr@rz.uni-jena.de

    2013-11-15

    For sealing of solid oxide fuel cells, glasses from which crystalline phases with high coefficient of thermal expansion (CTE) can be crystallized are required. In this paper, a new solid solution series BaZn{sub 2?x}Co{sub x}Si{sub 2}O{sub 7} (0sub 2}Si{sub 2}O{sub 7}). Sintered specimens were characterized by dilatometry. The introduction of Co{sup 2+} does not lead to a change in the space group. All compounds show a transition of a low to a high temperature modification. The attributed temperature increases from 300 °C for BaZn{sub 2}Si{sub 2}O{sub 7} to 850 °C for BaCo{sub 2}Si{sub 2}O{sub 7}. The volume expansion which runs parallel to the phase transition decreases with increasing cobalt concentration. The phase BaZn{sub 2}Si{sub 2}O{sub 7} shows the largest CTE and a steep volume effect during phase transition. For the compound BaZn{sub 0.25}Co{sub 1.75}Si{sub 2}O{sub 7} the CTE is minimum (8.6×10{sup ?6} K{sup ?1} (50–900 °C)) and increases again until for the compound BaCo{sub 2}Si{sub 2}O{sub 7} a CTE of 16.6×10{sup ?6} K{sup ?1} (50–900 °C) is reached. In the cobalt rich composition range, the CTEs are in the right range for high temperature fuel cells and can be adjusted by the composition. - Graphical abstract: The composition of the solid solution BaZn{sub 2?x}Co{sub x}Si{sub 2}O{sub 7} strongly affects the thermal expansion. Display Omitted - Highlights: • We examined the thermal expansion of solid solutions BaZn{sub 2?x}Co{sub x}Si{sub 2}O{sub 7} (0sub 2}Si{sub 2}O{sub 7} exhibits the highest thermal expansion due to a phase transition. • Substitution of small amounts of Zn{sup 2+} against Co{sup 2+} lead to decreasing thermal expansion. • The thermal expansions re-increased with further increasing Co{sup 2+} concentrations. • Seals based on these solid solutions should be suitable for solid oxide fuel cells.

  2. Incommensurate and commensurate modulations of Ba{sub 5}RTi{sub 3}Nb{sub 7}O{sub 30} (R?=?La, Nd) tungsten bronzes and the ferroelectric domain structures

    SciTech Connect (OSTI)

    Mao, Min Min; Li, Kun; Zhu, Xiao Li; Chen, Xiang Ming

    2015-04-07

    Incommensurate and commensurate structural modulations of Ba{sub 5}RTi{sub 3}Nb{sub 7}O{sub 30} (R?=?La, Nd) tungsten bronze ceramics were investigated by using a cooling holder equipped transmission electron microscopy in the temperature range from 100?K to 363?K. The incommensurate modulation was observed in both Ba{sub 5}LaTi{sub 3}Nb{sub 7}O{sub 30} and Ba{sub 5}NdTi{sub 3}Nb{sub 7}O{sub 30} at room temperature, while there was a transition from incommensurate tilted structure to commensurate superstructure for Ba{sub 5}NdTi{sub 3}Nb{sub 7}O{sub 30} with decreasing temperature. The incommensurate and commensurate modulations were determined by the A-site occupancy of Ba and R cations. The A-site disorder resulted in larger incommensurability parameter ? and the diffusion of the satellite reflection spots. The effect of A-site disorder on the coupling between long-range dipolar order and the commensurate modulation was also discussed. The obvious ferroelectric 180° domains with spike-like shape parallel to c axis were observed for Ba{sub 5}NdTi{sub 3}Nb{sub 7}O{sub 30}, while no macro ferroelectric domain was determined for Ba{sub 5}LaTi{sub 3}Nb{sub 7}O{sub 30}.

  3. Regional Public Coordination Transportation Plan Texoma Region #22 

    E-Print Network [OSTI]

    Texoma Council of Governments

    2006-12-01

    .......................................................................................................... 6 Regional Geography and Demographics..................................................................................... 6 Regional Agencies Responsible for Transportation Planning.................................................. 6 Descriptions... of the Region?s Public Transportation Providers................................................. 7 Coordinated Transportation Plan..................................................................................................... 8 Coordination Actions...

  4. A two-fold interpenetrating 3D metal-organic framework material constructed from helical chains linked via 4,4'-H{sub 2}bpz fragments

    SciTech Connect (OSTI)

    Xie Yiming; Zhao Zhenguo; Wu Xiaoyuan; Zhang Qisheng; Chen Lijuan; Wang Fei; Chen Shanci; Lu Canzhong

    2008-12-15

    A 3-connected dia-f-type metal-organic framework compound {l_brace}[Ag(L){sub 3/2}H{sub 2}PO{sub 4}]{r_brace}{sub n} (1) has been synthesized by self-assembly of 4,4'-H{sub 2}bpz (L=4,4'-H{sub 2}bpz=3,3',5,5'-tetramethyl-4,4'-bipyrazole) and Ag{sub 4}P{sub 2}O{sub 7} under hydrothermal conditions. It crystallizes in the tetragonal space group I4{sub 1}/acd with a=21.406(4) A, b=21.406(4) A, c=36.298(8) A, Z=32. X-ray single-crystal diffraction reveals that 1 has a three-dimensional framework with an unprecedented alternate left- and right-handed helices structure, featuring a non-uniform two-fold interpenetrated (4.14{sup 2}) net. Photoluminescent investigation reveals that the title compound displays interesting emissions in a wide region, which shows that the title compound may be a good potential candidate as a photoelectric material. - Graphical abstract: A 3-connected dia-f-type metal-organic framework compound [Ag(4,4'-bpz){sub 3/2}H{sub 2}PO{sub 4}] shows unprecedented alternating left- and right-handed helices structure, featuring a non-uniform two-fold interpenetrated (4.14{sup 2}) net.

  5. Reaction dynamics and photochemistry of divalent systems. [Reaction of Ba with NO sub 2 , H sub 2 O, methanol, ClO sub 2 , O sub 3; photodissociation of NO sub 3 radical and OClO

    SciTech Connect (OSTI)

    Davis, H.F.

    1992-05-01

    Results are presented of molecular beam studies of bimolecular and unimolecular reactions of Ba. Chapter 1 discusses the reaction Ba + NO{sub 2}. Formation of the dominant BaO({sup 1}{Sigma}) + NO products resulted primarily from decay of long-lived Ba{sup +}NO{sub 2}{sup {minus}} collision complexes. Secondary mechanisms led to formation of forward scattered, internally excited BaO, and BaNO + O. D{sub o}(Ba-NO) = 65{plus minus}20 kcal/mol. Reactions of ground state and electronically excited Ba with water and alcohols are examined in Chapter 2. Reaction of Ba({sup 1}S) + H{sup 2}O led to BaO + H{sub 2}, whereas excited state Ba({sup 1}D) + H{sub 2}O reacted to form BaOH + H. Collisions between Ba and CH{sub 3}OH led to BaOCH{sub 3} + H. Radical channels involve H-atom migration and are promoted by excitation of the incident Ba atom. In Chapter 3, reactions of Ba({sup 1}S) with ClO{sub 2}2 and O{sub 3} are discussed. Again, direct and complex mechanisms were observed. Formation of BaCl + O{sub 2} from decomposition of Ba{sup +}ClO{sub 2}{sup {minus}} accounted for 10% of total reaction crass section. Although Ba + O{sub 3} {yields} BaO + 0{sub 2} occurs primarily by direct reaction mechanisms, the secondary channel Ba + 0{sub 3} {yields} BaO{sub 2} + 0 involved decay of long lived Ba{sup +}O{sub 3}{sup {minus}} intermediates. D{sub o}(Ba{minus}O{sub 2}) = 120 {plus minus}20 kcal/mol. Photodissociation dynamics of NO{sub 3} is explored in chapter 4. Visible excitation leads to formation of NO + 0{sub 2} and NO{sub 2} + O. Wavelength dependence of branching ratios is investigated. D{sub o}(O-NO{sub 2}) = 48.55 kcal/mole ;and calculate {Delta}H{sub f}(NO{sub 3}) = 17.75 kcal/mole (298K). Chapter 5 discusses the photodissociation of OClO in a molecular beam. Although ClO({sup 2}II) + O({sup 3}P) is dominant, Cl({sup 2}P) + O{sub 2} also forms, with a max yield of 3.9{plus minus}0.8% near 404nm.

  6. Magnetic phase transitions in the UFe{sub 1{minus}{ital x}}Co{sub {ital x}}Al system

    SciTech Connect (OSTI)

    Tran, V.H.; Troc, R.; Zaleski, A.J.

    1996-12-01

    We present the results of x-ray-powder diffraction, magnetic susceptibility, magnetization, electrical resistivity, and M{umlt o}ssbauer effect measurements performed on the UFe{sub 1{minus}{ital x}}Co{sub {ital x}}Al system. The lattice parameters determined for the system show a sharp maximum for {ital a}({ital x}) and minimum for {ital c}({ital x}) approximately for {ital x}{approx_equal}0.3. From the point of view of magnetic properties this system appears to have two main concentration regions: (a) 0{le}{ital x}{lt}0.5 and (b) 0.5{le}{ital x}{le}1.0. The phases falling into the first region do not show a long-range magnetic ordering, while in the second region they become ferromagnetic with the maximum values of the Curie temperature and spontaneous magnetic moment at {ital x}{approx_equal}0.8. The ferromagnetic properties of the alloys at {ital B}=0 T with 0.5{le}{ital x}{le}0.98 are also confirmed by the M{umlt o}ssbauer effect experiment. Furthermore, we compare the magnetic behavior of UFe{sub 1{minus}{ital x}}Co{sub {ital x}}Al with that of the analogous UFe{sub 1{minus}{ital x}}Ni{sub {ital x}}Al. We find that the maximum ferromagnetic response appears in both systems by introduction to them of approximately 0.8 or 1 more electron, i.e., for the {ital x}=0.8 and 0.5 compositions, respectively. Moreover, we discuss the complex magnetic properties of pure U-Co-Al in more details and some view on its ground state is given. {copyright} {ital 1996 The American Physical Society.}

  7. Regional Analysis Briefs

    Reports and Publications (EIA)

    2028-01-01

    Regional Analysis Briefs (RABs) provide an overview of specific regions that play an important role in world energy markets, either directly or indirectly. These briefs cover areas that are currently major producers (Caspian Sea), have geopolitical importance (South China Sea), or may have future potential as producers or transit areas (East Africa, Eastern Mediterranean).

  8. Properties of Sb{sub 2}S{sub 3} and Sb{sub 2}Se{sub 3} thin films obtained by pulsed laser ablation

    SciTech Connect (OSTI)

    Virt, I. S.; Rudyj, I. O.; Kurilo, I. V.; Lopatynskyi, I. Ye.; Linnik, L. F.; Tetyorkin, V. V.; Potera, P.; Luka, G.

    2013-07-15

    The properties of Sb{sub 2}S{sub 3} and Sb{sub 2}Se{sub 3} thin films of variable thickness deposited onto Al{sub 2}O{sub 3}, Si, and KCl substrates are investigated by the method of pulsed laser ablation. The samples are obtained at a substrate temperature of 180 Degree-Sign C in a vacuum chamber with a residual pressure of 10{sup -5} Torr. The thickness of the films amounted to 40-1500 nm. The structure of the bulk material of the targets and films is investigated by the methods of X-ray diffraction and transmission high-energy electron diffraction, respectively. The electrical properties of the films are investigated in the temperature range of 253-310 K. It is shown that the films have semiconductor properties. The structural features of the films determine their optical parameters.

  9. Intrinsic Rashba-like splitting in asymmetric Bi{sub 2}Te{sub 3}/Sb{sub 2}Te{sub 3} heterogeneous topological insulator films

    SciTech Connect (OSTI)

    Liu, Xiaofei; Guo, Wanlin

    2014-08-25

    We show by density functional theory calculations that asymmetric hetero-stacking of Bi{sub 2}Te{sub 3}/Sb{sub 2}Te{sub 3} films can modulate the topological surface states. Due to the structure inversion asymmetry, an intrinsic Rashba-like splitting of the conical surface bands is aroused. While such splitting in homogeneous Bi{sub 2}Te{sub 3}-class topological insulators can be realized in films with more than three quintuple layers under external electric fields, the hetero-stacking breaks the limit of thickness for preserving the topological nature into the thinnest two quintuple layers. These results indicate that the hetero-stacking can serve as an efficient strategy for spin-resolved band engineering of topological insulators.

  10. Complete (O{sub 7},O{sub 8}) contribution to B{yields}X{sub s{gamma}} at O({alpha}{sub s}{sup 2})

    SciTech Connect (OSTI)

    Asatrian, H. M.; Ewerth, T.; Ferroglia, A.; Greub, C.; Ossola, G.

    2010-10-01

    We calculate the set of O({alpha}{sub s}{sup 2}) corrections to the branching ratio and to the photon energy spectrum of the decay process B{yields}X{sub s{gamma}} originating from the interference of diagrams involving the electromagnetic dipole operator O{sub 7} with diagrams involving the chromomagnetic dipole operator O{sub 8}. The corrections evaluated here are one of the elements needed to complete the calculations of the B{yields}X{sub s{gamma}} branching ratio at next-to-next-to-leading order in QCD. We conclude that this set of corrections does not change the central value of the standard model prediction for Br(B{yields}X{sub s{gamma}}) by more than 1%.

  11. Enhancing solar photocatalytic detoxification by adsorption of porphyrins onto TiO sub 2

    SciTech Connect (OSTI)

    Majumder, S.A.; Ondrias, M.R. . Dept. of Chemistry); Prairie, M.R.; Shelnutt, J.A. )

    1991-01-01

    Titanium dioxide (TiO{sub 2}) is a known photocatalyst for solar detoxification of water containing organic contaminants including PCB's and dioxins. Unfortunately, the UV light used by the photocatalyst only comprises about 4% of the strong spectrum. Metalloporphyrins strongly absorb in the visible and near infrared region. Using visible light, we have investigated Ni(II) uroporphyrin (NiUroP), Sn(IV)Cl{sub 2} uroporphyrin (SnUroP) and Sn(IV)Cl{sub 2} tetrakis(p-carboxyphenyl) porphyrin (SnTCPP) as possible enhancers of destruction of a model organic compound, salicylic acid (SA), by means of photosensitization of colloidal TiO{sub 2} particles. All three porphyrins are found to adsorb reversibly onto the colloidal TiO{sub 2} upon variation of pH. Adsorption of porphyrins results in the increased colloidal stability of fine TiO{sub 2} particles in the pH range 5--8. While NiUroP on TiO{sub 2} does not show any enhancement of photodestruction, the adsorption of SnUroP increases the destruction rate compared to that of the bare TiO{sub 2} surface. The effect of ambient oxygen on the observed photolability of the Sn porphyrins and enhancement of photodestruction of SA was also investigated. SnTCPP does not photodecompose upon illumination either in the presence or absence of TiO{sub 2}, but neither does it bind to the photocatalyst at pH 6. At pH 4.5 it adsorbs onto TiO{sub 2} but it also photodecompose at this pH. We are attempting to stabilize the adsorbed porphyrins by adding suitable peripheral substituents onto the porphyrin macrocycle. 27 refs., 6 figs.

  12. Branching ratios from B{sub s} and {Lambda}{sub b}{sup 0}

    SciTech Connect (OSTI)

    Matthew S. Martin

    2004-05-28

    CDF Run II relative branching ratio measurements for 65 pb{sup -1} of data in the channels B{sub s} {yields} D{sub s}{sup {-+}}{pi}{sup {-+}}, {Lambda} {sub b}{sup 0} {yields} {Lambda}{sub c}{sup {+-}}{pi}{sup {-+}} and B {yields} h{sup +}h{sup -} are presented. Further, an observation of B{sub s} {yields} K{sup {+-}} K{sup {-+}} and a measurement of A{sub CP} are presented.

  13. Superconductivity in textured Bi clusters/Bi{sub 2}Te{sub 3} films

    SciTech Connect (OSTI)

    Le, Phuoc Huu [Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 30049, Taiwan (China); Faculty of Basic Sciences, Can Tho University of Medicine and Pharmacy, 179 Nguyen Van Cu Street, Can Tho (Viet Nam); Tzeng, Wen-Yen; Chen, Hsueh-Ju; Luo, Chih Wei, E-mail: cwluo@mail.nctu.edu.tw [Department of Electrophysics, National Chiao Tung University, Hsinchu 300, Taiwan (China); Lin, Jiunn-Yuan [Institute of Physics, National Chiao Tung University, Hsinchu 300, Taiwan (China); Leu, Jihperng, E-mail: jimleu@mail.nctu.edu.tw [Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 30049, Taiwan (China)

    2014-09-01

    We report superconductivity at an onset critical temperature below 3.1 K in topological insulator ?200-nm-thick Bi{sub 2}Te{sub 3} thin films grown by pulsed laser deposition. Using energy-dispersive X-ray spectroscopy elemental mapping and Auger electron spectroscopy elemental depth profiling, we clearly identified bismuth (Bi) precipitation and Bi cluster signatures. Superconductivity in the Bi{sub 2}Te{sub 3} films was attributed to the proximity effect of Bi clusters precipitated on the surface of the Bi{sub 2}Te{sub 3} films.

  14. Synthesis, crystal structure, and vibrational spectroscopic and UV-visible studies of Cs{sub 2}MnP{sub 2}O{sub 7}

    SciTech Connect (OSTI)

    Kaoua, Saida; Krimi, Saida; Pechev, Stanislav; Gravereau, Pierre; Chaminade, Jean-Pierre; Couzi, Michel; El Jazouli, Abdelaziz

    2013-02-15

    A new member of the A{sub 2}MP{sub 2}O{sub 7} diphosphate family, Cs{sub 2}MnP{sub 2}O{sub 7}, has been synthesized and structurally characterized. The crystal structure was determined by single crystal X-Ray diffraction. Cs{sub 2}MnP{sub 2}O{sub 7} crystallizes in the orthorhombic system, space group Pnma ( Music-Sharp-Sign 62), with the unit cell parameters a=16.3398(3), b=5.3872(1), c=9.8872(2) A, Z=4 and V=870.33(3) A{sup 3}. The structure parameters were refined to a final R{sub 1}/wR{sub 2}=0.0194/0.0441 for 1650 observed reflections. The 2D framework of Cs{sub 2}MnP{sub 2}O{sub 7} structure consists of P{sub 2}O{sub 7} and MnO{sub 5} units. The corner-shared MnO{sub 5} and P{sub 2}O{sub 7} units are alternately arranged along the b axis to form [(MnO)P{sub 2}O{sub 7}]{sub {infinity}} chains. These chains are interconnected by an oxygen atom to form sheets parallel to the (b, c) plane. The cesium atoms are located between the sheets in 9- and 10-fold coordinated sites. The infrared and Raman vibrational spectra have been investigated. A factor group analysis leads to the determination of internal modes of (P{sub 2}O{sub 7}) groups. UV-visible spectrum consists of weak bands, between 340 and 700 nm, assigned to the forbidden d-d transitions of Mn{sup 2+} ion, and of a strong band around 250 nm, attributed to the O--Mn charge transfer. - Graphical abstract: Structure of Cs{sub 2}MnP{sub 2}O{sub 7}: The 2D structure of Cs{sub 2}MnP{sub 2}O{sub 7} is built from P{sub 2}O{sub 7} diphosphate groups and MnO{sub 5} square pyramids which share corners and form [(MnO)P{sub 2}O{sub 7}]{sub {infinity}} chains along b axis. These chains are interconnected by an oxygen atom to form wavy (MnP{sub 2}O{sub 7}){sup 2-} sheets parallel to the (b, c) plane. The cesium ions are located between these sheets in the inter-layers space, in zigzag positions. Highlights: Black-Right-Pointing-Pointer A new diphosphate, Cs{sub 2}MnP{sub 2}O{sub 7}, has been synthesized and structurally characterized. Black-Right-Pointing-Pointer The structure consists of a 2D framework built up from (MnP{sub 2}O{sub 7}) sheets. Black-Right-Pointing-Pointer The sheets consist of [(MnO)P{sub 2}O{sub 7}]{sub {infinity}} chains formed by P{sub 2}O{sub 7} units and MnO{sub 5} square pyramids. Black-Right-Pointing-Pointer A factor group analysis leads to the determination of internal modes of (P{sub 2}O{sub 7}) groups. Black-Right-Pointing-Pointer UV-visible spectrum consists bands assigned to d-d transitions of Mn{sup 2+} ion and to O--Mn CT.

  15. Morphology control of open-framework zinc phosphate Zn{sub 4}(H{sub 3}O)(NH{sub 4}){sub 3}(PO{sub 4}){sub 4} via microwave-assisted technique

    SciTech Connect (OSTI)

    Ding, Ling; Song, Yu; Yang, Wei; Xue, Run-Miao; Zhai, Shang-Ru; An, Qing-Da

    2013-08-15

    Open-framework zinc phosphates were synthesized by microwave-assisted technique, and it was shown that the morphology of as-prepared materials could be easily tailored by changing synthesis temperature, reaction time and pH value. During the synthesis, when the reaction temperature increases from 130 °C to 220 °C, the products transformed from hexagonal prisms to polyhedron along with the disappearance of the hexagonal prisms vertical plane. Simultaneously, both the reaction time and pH value could promote the nucleation and growth of crystal particles. More interestingly, the target products with different morphologies could be obtained by varying the usage of NaOH or NH{sub 3}·H{sub 2}O at 130 °C during the microwave synthesis process. - Graphical abstract: Zinc phosphates with variable morphologies can be obtained by simply tuning the microwave-heating temperatures. Display Omitted - Highlights: • Synthesis of open-framework Zn{sub 4} (H{sub 3}O) (NH{sub 4}){sub 3}(PO{sub 4}){sub 4} compounds employing microwave technique. • Dependence of morphology on the reaction conditions. • Morphology transformation from hexagonal prisms to polyhedron was observed.

  16. Lattice instabilities in heavy fermion superconductors. [CeCu/sub 2/Si/sub 2/; CeAl/sub 3/; CeCu/sub 6/; UBe/sub 13/; UPt/sub 3/

    SciTech Connect (OSTI)

    Wohlleben, D.

    1987-01-01

    This paper shows that while in nonsuperconducting HF systems such as CeCu/sub 6/, CeAl/sub 3/ and stoichiometric CeCu/sub 2/Si/sub 2/, the large electronic ..gamma.. is due to a very narrow f band, in the three HF superconductors UBe/sub 13/, UPt/sub 3/ and nonstochiometric CeCu/sub 2/Si/sub 2/, it is not. The f band of these systems, as measured by their response to magnetic fields in three different ways, is much wider than suggested by the large ..gamma... According to their actual f band width, the HF superconductors belong into the Bantam Fermion class. It is argued that most of the large ..gamma.. of the HF superconductors is not of electronic origin and that it is instead caused by the precursor of a martensitic phase transition of the lattice or by a crystallographic phase mixture, i.e., that it is due to the displacive degrees of freedom. This suggests that the superconductivity of all three HF superconductors is caused by some special, low energy phonons rather than by a narrow f band. 52 refs., 4 figs., 3 tabs.

  17. 1-D and 2-D homoleptic dicyanamide structures, [Ph{sub 4}P]{sub 2}{Co{sup II}[N(CN){sub 2}]{sub 4}} and [Ph{sub 4}P]{M[N(CN){sub 2}]{sub 3}} (M = Mn, Co).

    SciTech Connect (OSTI)

    Raebiger, J. W.; Manson, J. L.; Sommer, R. D.; Geiser, U.; Rheingold, A. L.; Miller, J. S.; Materials Science Division; Univ. of Utah; Univ. of Delaware

    2001-05-21

    The homoleptic complexes [Ph{sub 4}P]{sub 2}{l_brace}Co[N(CN){sub 2}]{sub 4}{r_brace} and [Ph{sub 4}P]{l_brace}M[N(CN){sub 2}]{sub 3}{r_brace} [ M = Co, Mn] have been structurally as well as magnetically characterized. The complexes containing {l_brace}M[N(CN){sub 2}]{sub 4}{r_brace}{sup 2-} form 1-D chains, which are bridged via a common dicyanamide ligand in {l_brace}M[N(CN){sub 2}]{sub 3}{r_brace}{sup -} to form a 2-D structure. The five-atom [NCNCN]{sup -} ligands lead to a {sup 4}T{sub 1g} ground state for Co(II) which has an unquenched spin-orbit coupling that is reflected in the magnetic properties. Long-range magnetic ordering was not observed in any of these materials.

  18. Pressure dependence of the exchange interaction in the dimeric single-molecule magnet [Mn{sub 4}O{sub 3}Cl{sub 4}(O{sub 2}CEt){sub 3}(py){sub 3}]{sub 2} from inelastic neutron scattering

    SciTech Connect (OSTI)

    Sieber, A.; Waldmann, O.; Ochsenbein, S. T.; Carver, G.; Guedel, H. U.; Foguet-Albiol, D.; Christou, G.; Mutka, H.; Fernandez-Alonso, F.; Mezouar, M.; Weber, H. P.

    2006-07-01

    The low-lying magnetic excitations in the dimers of single-molecule magnets [Mn{sub 4}O{sub 3}Cl{sub 4}(O{sub 2}CEt){sub 3}(py){sub 3}]{sub 2}, or (Mn{sub 4}){sub 2}, are studied by inelastic neutron scattering as a function of hydrostatic pressure. The anisotropy parameters D and B{sub 0}{sup 4}, which describe each Mn{sub 4} subunit, are essentially pressure independent, while the antiferromagnetic exchange coupling J between the two Mn{sub 4} subunits strongly depends on pressure, with an increase of 42% at 17 kbar. Additional pressure-dependent powder x-ray measurements allow a structural interpretation of the findings.

  19. Expresso -nica Dez crebros sub-35

    E-Print Network [OSTI]

    Instituto de Sistemas e Robotica

    Expresso - Única Dez cérebros sub-35 Autor: N.D. Id: 1385348 Data Publicação: 06-11-2010 Fonte Âmbito: Nacional AlturaxLargura: 27,41cmx19,79cm #12;Expresso - Única Dez cérebros sub-35 Autor: N.D. Id - Única Dez cérebros sub-35 Autor: N.D. Id: 1385350 Data Publicação: 06-11-2010 Fonte: Jornal Edição: 1984

  20. Concentration effect of Er{sup 3+} ions on structural and spectroscopic properties of CdNb{sub 2}O{sub 6} phosphors

    SciTech Connect (OSTI)

    Ghafouri, Sanaz Aian; Erdem, Murat; Ekmekçi, M. Kaan; Mergen, Ayhan; Özen, Gönül

    2014-12-15

    Excitation and emission spectra of a visible room-temperature Er{sup 3+} ions luminescence from powders. - Highlights: • This is the first report on spectroscopic properties of CdNb{sub 2}O{sub 6}:Er{sup 3+}. • The crystalline sizes are affected as the concentration of Er{sup 3+} ions increased. • Quenching of the luminescence was observed to be above 1.0 mol% Er{sup 3+}. - Abstract: This study is focused on the synthesis and characterization of CdNb{sub 2}O{sub 6} compounds doped with of Er{sup 3+} ions. Powders were synthesized by using the molten salt method and annealed at 900 °C for 4 h. The synthesized particles were structurally characterized by using X-ray diffraction, scanning electron microscopy. A single phase of the CdNb{sub 2}O{sub 6} was determined and the size of the particles was found to be affected by the presence and the concentration of Er{sup 3+} ions. Luminescence properties of each sample were investigated by measuring accurately the emission and excitation spectra at room temperature in the wavelength range of 200–1700 nm by exciting the Er{sup 3+} ions at 379 nm and 805 nm. Quenching of the luminescence in both visible and near infrared spectral regions was observed to be above 1.0 mol% Er{sup 3+} concentration.

  1. Comparison of the structural and optical properties of porous In{sub 0.08}Ga{sub 0.92}N thin films synthesized by electrochemical etching

    SciTech Connect (OSTI)

    Abud, Saleh H., E-mail: salehhasson71@gmail.com [Nano-Optoelectronics Research and Technology (N.O.R.) Laboratory, School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia); Department of Physics, College of Science, University of Kufa (Iraq); Hassan, Z.; Yam, F.K. [Nano-Optoelectronics Research and Technology (N.O.R.) Laboratory, School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia); Ghazai, A.J. [Department of Physics, College of Science, Thi-Qar University (Iraq)

    2014-04-01

    This paper presents the structural and optical study of porous (1 µm) In{sub 0.08}Ga{sub 0.92}N synthesized by photoelectrochemical etching under various conditions. Field emission scanning electron microscope and atomic force microscope images showed that the pre-etched thin films have a sufficiently smooth surface over a large region with wurtzite structure. The roughness increased with an increase in etching duration. The blue shift phenomenon was measured for photoluminescence emission peaks at 300 K. The energy band gap increased to be 3.18 and 3.16 eV for post-etched films at ratios of 1:4 and 1:5, respectively. At the same time, the photoluminescence intensities of the post-etched thin films indicated that the optical properties have been enhanced. - Graphical abstract: PL spectra of the as-grown and porous In{sub 0.08}Ga{sub 0.92}N under various etching duration. - Highlights: • Nanoporous structures of In{sub 0.08}Ga{sub 0.92}N. • The roughness of the porous thin films increased with an increase in etching durations. • No phase segregation in XRD pattern. • Blue shifts were observed in the PL spectra of the post-etched films.

  2. Synthesis of Bi{sub 1.8}Pb{sub 0.4}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} superconductor

    DOE Patents [OSTI]

    Smith, M.G.

    1996-10-29

    Two-powder processes for the synthesis of superconducting (Bi, Pb)-2223/Ag-clad wires by the oxide-powder-in-the-robe are provided. The first precursor powder, of nominal stoichiometry CaCuO{sub x}, is a solution-synthesized mixture of Ca{sub 0.45}Cu{sub 0.55}O{sub 2} and CaO. Using these oxide precursor mixtures, superconducting tapes with well-aligned grains and reproducible critical current densities J{sub c} in the range of 20,000 to 26,000 A/cm{sup 2} at 75 K in self-field after annealing less than 200 hours were obtained. 2 figs.

  3. Simultaneous presence of (Si{sub 3}O{sub 10}){sup 8?} and (Si{sub 2}O{sub 7}){sup 6?} groups in new synthetic mixed sorosilicates: BaY{sub 4}(Si{sub 2}O{sub 7})(Si{sub 3}O{sub 10}) and isotypic compounds, studied by single-crystal X-ray diffraction, Raman spectroscopy and DFT calculations

    SciTech Connect (OSTI)

    Wierzbicka-Wieczorek, Maria; Többens, Daniel M.; Kolitsch, Uwe; Tillmanns, Ekkehart

    2013-11-15

    Three new, isotypic silicate compounds, BaY{sub 4}(Si{sub 2}O{sub 7})(Si{sub 3}O{sub 10}), SrYb{sub 4}(Si{sub 2}O{sub 7})(Si{sub 3}O{sub 10}) and SrSc{sub 4}(Si{sub 2}O{sub 7})(Si{sub 3}O{sub 10}), were synthesized using high-temperature flux growth techniques, and their crystal structures were solved from single-crystal X-ray intensity data: monoclinic, P2{sub 1}/m, with a=5.532(1)/5.469(1)/5.278(1), b=19.734(4)/19.447(4)/19.221(4), c=6.868(1)/6.785(1)/6.562(1) Å, ?=106.53(3)/106.20(3)/106.50(3)°, V=718.8(2)/693.0(2)/638.3(2) Å{sup 3}, R(F)=0.0225/0.0204/0.0270, respectively. The topology of the novel structure type contains isolated horseshoe-shaped Si{sub 3}O{sub 10} groups (Si–Si–Si=93.15–95.98°), Si{sub 2}O{sub 7} groups (Si–O{sub bridge}–Si=180°, symmetry-restricted) and edge-sharing M(1)O{sub 6} and M(2)O{sub 6} octahedra. Single-crystal Raman spectra of the title compounds were measured and compared with Raman spectroscopic data of chemically and topologically related disilicates and trisilicates, including BaY{sub 2}(Si{sub 3}O{sub 10}) and SrY{sub 2}(Si{sub 3}O{sub 10}). The band assignments are supported by additional theoretical calculation of Raman vibrations by DFT methods. - Graphical abstract: View of BaY{sub 4}(Si{sub 2}O{sub 7})(Si{sub 3}O{sub 10}) along [100], showing zigzag chains and the tri- and disilicate groups. The unit cell is outlined. Display Omitted - Highlights: • We report a novel interesting crystal structure type for mixed sorosilicates containing Y, Yb, and Sc. • Synthesis of such mixed sorosilicates is possible by a high-temperature flux-growth technique. • Calculation of Raman vibrations by advanced DFT methods allows a considerably improved interpretation of measured Raman spectra.

  4. Regional partnerships lead US carbon sequestration efforts

    SciTech Connect (OSTI)

    NONE

    2007-07-01

    During the sixth annual conference on carbon capture and sequestration, 7-10 May 2007, a snapshot was given of progress on characterization efforts and field validation tests being carried out through the Carbon Sequestration Regional Partnership Initiative. The initiative is built on the recognition that geographical differences in fossil fuel/energy use and CO{sub 2} storage sinks across North America will dictate approaches to carbon sequestration. The first characterization phase (2003-2005) identified regional opportunities and developed frameworks to validate and deploy technologies. The validation phase (2005-2009) includes 10 enhanced oil recovery/enhanced gas recovery field tests in progress in Alberta and six US states and is applying lessons learned from these operations to sequestration in unmineable coal seams. Storage in saline formations are the focus of 10 field tests, and terrestrial sequestration will be studied in 11 other projects. 1 tab., 3 photos.

  5. Effects of oxygen vacancies on dielectric, electrical, and ferroelectric properties of Ba{sub 4}Nd{sub 2}Fe{sub 2}Nb{sub 8}O{sub 30} ceramics

    SciTech Connect (OSTI)

    Fei Liu, Shu; Jun Wu, Yong; Li, Juan; Ming Chen, Xiang

    2014-02-24

    Effects of oxygen vacancies on the dielectric, electrical, and ferroelectric properties of Ba{sub 4}Nd{sub 2}Fe{sub 2}Nb{sub 8}O{sub 30} ceramics were investigated. A dielectric relaxation above T{sub c} can be ascribed to the trap-controlled ac conduction around doubly ionized oxygen vacancies. The dc conductivity of the N{sub 2}-annealed and O{sub 2}-annealed samples is attributed to the long-range motion of the V{sub o}{sup ??}, and that of the as-sintered sample is considered to be governed by the electronic and oxygen-vacancy ionic mixed conduction mechanism. Low concentration and random distributed oxygen vacancies are propitious to the domain switching, while high concentration and allied oxygen defects hinder the domain-wall movement.

  6. Study on the Ge{sub 1?x}Sn{sub x}/HfO{sub 2} interface and its impacts on Ge{sub 1?x}Sn{sub x} tunneling transistor

    SciTech Connect (OSTI)

    Qiu, Yingxin; Wang, Runsheng, E-mail: ruhuang@pku.edu.cn, E-mail: r.wang@pku.edu.cn; Huang, Qianqian; Huang, Ru, E-mail: ruhuang@pku.edu.cn, E-mail: r.wang@pku.edu.cn [Key Laboratory of Microelectronic Devices and Circuits, Institute of Microelectronics, Peking University, Beijing 100871 (China)

    2014-06-21

    In this paper, we employ first-principle calculation to investigate the Ge{sub 1?x}Sn{sub x}/HfO{sub 2} interface, and then evaluate its impacts on Ge{sub 1?x}Sn{sub x} tunneling field-effect transistor (TFET). First-principle calculations of Ge{sub 1?x}Sn{sub x}/HfO{sub 2} interfaces in the oxygen-rich process atmosphere indicate that the interface states originate from the Ge and Sn dangling bond, rather than Hf-bond. The total density of state shows that there are more interface states in the semiconductor bandgap with increasing Sn fraction. By further incorporating the material and interface parameters from density functional theory calculation into advanced device simulation, the electrical characteristics of Ge{sub 1?x}Sn{sub x} TFET are investigated. Removing the Sn atom from the first atom layer of Ge{sub 1?x}Sn{sub x} in device processes is found to be beneficial to reduce the degradations. For the degradation mechanisms, the trap-assisted-tunneling is the dominant mechanism at the low Sn fraction, and enhanced Shockley-Read-Hall recombination induced by traps becomes the dominant mechanism with increasing Sn fraction. The results are helpful for the interface optimization of Ge{sub 1?x}Sn{sub x} TFET.

  7. Structural and conductivity studies of CsK(SO{sub 4}){sub 0.32}(SeO{sub 4}){sub 0.68}Te(OH){sub 6}

    SciTech Connect (OSTI)

    Djemel, M.; Abdelhedi, M.; Dammak, M.; Kolsi, A.W.

    2012-12-15

    The compound CsK(SO{sub 4}){sub 0.32}(SeO{sub 4}){sub 0.68}Te(OH){sub 6} crystallizes in the monoclinic P2{sub 1}/n space group. It was analyzed, at room temperature, using X-ray diffractometer data. The main feature of these atomic arrangements is the coexistence of three and different anions (SO{sub 4}{sup 2-}, SeO{sub 4}{sup 2-} and TeO{sub 6}{sup 6-}groups) in the unit cell, connected by hydrogen bonds which make the building of the crystal. The thermal analysis of the title compound shows three distinct endothermal peaks at 435, 460 and 475 K. Complex impedance measurements are performed on this material as a function of both temperature and frequency. The electric conduction has been studied. The temperature dependence on the conductivity indicates that the sample became an ionic conductor at high temperature. - Graphical abstract: Projection of crystal structure CsK(SO{sub 4}){sub 0.32}(SeO{sub 4}){sub 0.68}Te(OH){sub 6} on the ab plane. Highlights: Black-Right-Pointing-Pointer We have studied the results of the crystal structure of the new mixed compound. Black-Right-Pointing-Pointer We have characterized the phase transition observed in DSC curve. Black-Right-Pointing-Pointer The protonic conduction in our material is probably due to a hopping mechanism.

  8. Recovery of original superconducting properties in ion-irradiated Y sub 1 Ba sub 2 Cu sub 3 O sub 7 minus x thin films

    SciTech Connect (OSTI)

    Vadlamannati, S.; England, P.; Stoffel, N.G.; Ramesh, R.; Ravi, T.S.; Hwang, D.M.; Findikoglu, A.; Li, Q.; Venkatesan, T.; McLean, W.L. )

    1990-11-19

    The changes in the superconducting properties of {ital in} {ital situ} pulsed laser deposited Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7}{sub {minus}{ital x}} thin films caused by irradiation with 200 keV He{sup +} ions are due to both oxygen loss as well as oxygen and cationic displacements induced by the irradiation. This is demonstrated by a study of the recovery of these defects by plasma oxidation and relatively low temperature ({approximately}600 {degree}C) annealing in oxygen. Plasma oxidation of films irradiated to low fluences enables the replacement of oxygen atoms in the lattice, leading to a substantial recovery of {ital T}{sub {ital c}0}, {ital J}{sub {ital c}}, and normal state resistivity. Irradiation-induced oxygen and cationic displacements and other microscopic defects can be further annealed out at relatively low temperatures leading to an almost full recovery of {ital T}{sub {ital c}0}, {ital J}{sub {ital c}}, and normal state resistivity. A transmission electron microscope study of irradiated films shows evidence that they are structurally disordered.

  9. Electric field effect in high T sub c superconducting ultrathin YBa sub 2 Cu sub 3 O sub 7 minus x films

    SciTech Connect (OSTI)

    Xi, X.X.; Li, Q.; Doughty, C.; Kwon, C.; Bhattacharya, S.; Findikoglu, A.T.; Venkatesan, T. )

    1991-12-23

    A multilayer high {ital T}{sub {ital c}} superconducting field-effect transistor-like structure was made from ultrathin YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} films. An epitaxially grown dielectric SrTiO{sub 3} insulation layer, which had a forward bias breakdown voltage of about 20 V, allowed an electric field induced change in the channel layer of 1.25{times}10{sup 13} carrier/cm{sup 2} per volt of the gate voltage. A significant modulation of the normal state and superconducting properties was observed in samples with YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} channel layers of a few unit cells thick. By applying gate voltage of different polarities, {ital T}{sub {ital c}} was both suppressed and enhanced by {similar to}1 K. The resistance was modulated by as much as 20% in the normal state and by over 1500% near the zero resistance temperature.

  10. Biotechnology Adoption in Sub-Saharan Africa

    E-Print Network [OSTI]

    Midling, Michael B

    2011-01-01

    Nigeria lacks Berkeley Undergraduate Journal: Volume 24, Issue 3 Biotechnology Adoption in Sub-Saharan Africa Michael Baihua Midling regular energy,

  11. Magnetorefractive effect in manganites with a colossal magnetoresistance in the visible spectral region

    SciTech Connect (OSTI)

    Sukhorukov, Yu. P., E-mail: suhorukov@imp.uran.ru; Telegin, A. V. [Russian Academy of Sciences, Institute of Metal Physics, Ural Branch (Russian Federation); Granovsky, A. B., E-mail: granov@magn.ru; Gan'shina, E. A. [Moscow State University, Faculty of Physics (Russian Federation); Zhukov, A.; Gonzalez, J. [Universidad del Pais Vasco (UPV)/Euskal Herriko Unibertsitatea (EHU), Departamento de Fisica de Materiales, Facultad de Quimica (Spain); Herranz, G. [Institut de Ciencia de Materials de Barcelona (ICMAB)-CSIC (Spain); Caicedo, J. M. [Universidad del Pais Vasco (UPV)/Euskal Herriko Unibertsitatea (EHU), Departamento de Fisica de Materiales, Facultad de Quimica (Spain); Yurasov, A. N. [Moscow State Institute of Radio-Engineering, Electronics, and Automation (Technical University) (Russian Federation); Bessonov, V. D. [Russian Academy of Sciences, Institute of Metal Physics, Ural Branch (Russian Federation); Kaul', A. R.; Gorbenko, O. Yu.; Korsakov, I. E. [Moscow State University, Faculty of Physics (Russian Federation)

    2012-01-15

    The magnetotransmission, magnetoreflection, and magnetoresistance of the La{sub 0.7}Ca{sub 0.3}MnO{sub 3} and La{sub 0.9}Ag{sub 0.1}MnO{sub 3} epitaxial films have been investigated. It has been found that the films exhibit a significant magnetorefractive effect in the case of reflection and transmission of light in the fundamental absorption region both in the vicinity of the Curie temperature and at low temperatures. It has been shown that the magnetorefractive effect in the infrared spectral region of the manganites is determined by a high-frequency response to magnetoresistance, whereas the magnetorefractive effect in the visible spectral region of these materials is associated with a change in the electronic structure in response to a magnetic field, which, in turn, leads to a change in the electron density of states, the probability of interband optical transitions, and the shift of light absorption bands. The obtained values of the magnetotransmittance and magnetoreflectance in the visible spectral region are less than those observed in the infrared region of the spectrum, but they are several times greater than the linear magneto-optical effects. As a result, the magnetorefractive effect, which is a nongyrotropic phenomenon, makes it possible to avoid the use of light analyzers and polarizers in optical circuits.

  12. Area of Interest 1, CO<sub>2sub> at the Interface. Nature and Dynamics of the Reservoir/Caprock Contact and Implications for Carbon Storage Performance

    SciTech Connect (OSTI)

    Mozley, Peter; Evans, James; Dewers, Thomas

    2014-10-31

    We examined the influence of geologic features present at the reservoir/caprock interface on the transmission of supercritical CO<sub>2sub> into and through caprock. We focused on the case of deformation-band faults in reservoir lithologies that intersect the interface and transition to opening-mode fractures in caprock lithologies. Deformation-band faults are exceeding common in potential CO<sub>2sub> injection units and our fieldwork in Utah indicates that this sort of transition is common. To quantify the impact of these interface features on flow and transport we first described the sedimentology and permeability characteristics of selected sites along the Navajo Sandstone (reservoir lithology) and Carmel Formation (caprock lithology) interface, and along the Slickrock Member (reservoir lithology) and Earthy Member (caprock lithology) of the Entrada Sandstone interface, and used this information to construct conceptual permeability models for numerical analysis. We then examined the impact of these structures on flow using single-phase and multiphase numerical flow models for these study sites. Key findings include: (1) Deformation-band faults strongly compartmentalize the reservoir and largely block cross-fault flow of supercritical CO<sub>2sub>. (2) Significant flow of CO<sub>2sub> through the fractures is possible, however, the magnitude is dependent on the small-scale geometry of the contact between the opening-mode fracture and the deformation band fault. (3) Due to the presence of permeable units in the caprock, caprock units are capable of storing significant volumes of CO<sub>2sub>, particularly when the fracture network does not extend all the way through the caprock. The large-scale distribution of these deformation-bandfault-to-opening-mode-fractures is related to the curvature of the beds, with greater densities of fractures in high curvature regions. We also examined core and outcrops from the Mount Simon Sandstone and Eau Claire Formation reservoir/caprock interface in order to extend our work to a reservoir/caprock pair this is currently being assessed for long-term carbon storage. These analyses indicate that interface features similar to those observed at the Utah sites 3 were not observed. Although not directly related to our main study topic, one byproduct of our investigation is documentation of exceptionally high degrees of heterogeneity in the pore-size distribution of the Mount Simon Sandstone. This suggests that the unit has a greater-than-normal potential for residual trapping of supercritical CO<sub>2sub>.

  13. Effect of postdeposition annealing on the electrical properties of ?-Ga{sub 2}O{sub 3} thin films grown on p-Si by plasma-enhanced atomic layer deposition

    SciTech Connect (OSTI)

    Altuntas, Halit; Donmez, Inci; Ozgit-Akgun, Cagla; Biyikli, Necmi

    2014-07-01

    Ga{sub 2}O{sub 3} dielectric thin films were deposited on (111)-oriented p-type silicon wafers by plasma-enhanced atomic layer deposition using trimethylgallium and oxygen plasma. Structural analysis of the Ga{sub 2}O{sub 3} thin films was carried out using grazing-incidence x-ray diffraction. As-deposited films were amorphous. Upon postdeposition annealing at 700, 800, and 900?°C for 30?min under N{sub 2} ambient, films crystallized into ?-form monoclinic structure. Electrical properties of the ?-Ga{sub 2}O{sub 3} thin films were then investigated by fabricating and characterizing Al/?-Ga{sub 2}O{sub 3}/p-Si metal–oxide-semiconductor capacitors. The effect of postdeposition annealing on the leakage current densities, leakage current conduction mechanisms, dielectric constants, flat-band voltages, reverse breakdown voltages, threshold voltages, and effective oxide charges of the capacitors were presented. The effective oxide charges (Q{sub eff}) were calculated from the capacitance–voltage (C-V) curves using the flat-band voltage shift and were found as 2.6?×?10{sup 12}, 1.9?×?10{sup 12}, and 2.5?×?10{sup 12} cm{sup ?2} for samples annealed at 700, 800, and 900?°C, respectively. Effective dielectric constants of the films decreased with increasing annealing temperature. This situation was attributed to the formation of an interfacial SiO{sub 2} layer during annealing process. Leakage mechanisms in the regions where current increases gradually with voltage were well fitted by the Schottky emission model for films annealed at 700 and 900?°C, and by the Frenkel–Poole emission model for film annealed at 800?°C. Leakage current density was found to improve with annealing temperature. ?-Ga{sub 2}O{sub 3} thin film annealed at 800?°C exhibited the highest reverse breakdown field value.

  14. Ab-initio structure determination of {beta}-La{sub 2}WO{sub 6}

    SciTech Connect (OSTI)

    Chambrier, M-H.; Kodjikian, S.; Ibberson, R.M.; Goutenoire, F.

    2009-02-15

    The structure of the low-temperature form of {beta}-La{sub 2}WO{sub 6} has been determined from laboratory X-ray, neutron time-of-flight and electron diffraction data. This tungstate crystallizes in the non-centrosymmetric orthorhombic space group (no. 19) P2{sub 1}2{sub 1}2{sub 1}, with Z=8, a=7.5196(1) A, b=10.3476(1) A, c=12.7944(2) A, and a measured density 7.37(1) g cm{sup -3}. The structure consists of tungsten [WO{sub 6}] octahedra and tetrahedral [OLa{sub 4}]. Tungsten polyhedra are connected such that [W{sub 2}O{sub 11}]{sup 10-} units are formed. - Graphical abstract: Projection of La{sub 2}WO{sub 6} structure along [100]. The structure could be described by [W{sub 2}O{sub 11}]{sup -10} structural unit formed by two corner-sharing octahedra.

  15. Method for improving voltage regulation of batteries, particularly Li/FeS.sub.2 thermal batteries

    DOE Patents [OSTI]

    Godshall, Ned A. (Albuquerque, NM)

    1988-01-01

    Batteries are improved, especially with respect to voltage regulation properties, by employing as anode and cathode compositions, those which fall in a thermodynamically invariant region of the metallurgical phase diagram of the combination of the constituent components. The invention is especially useful in the Li/FeS.sub.2 system.

  16. Method for improving voltage regulation of batteries, particularly Li/FeS/sub 2/ thermal batteries

    DOE Patents [OSTI]

    Godshall, N.A.

    1986-06-10

    Batteries are improved, especially with respect to voltage regulation properties, by employing as anode and cathode compositions, those which fall in a thermodynamically invariant region of the metallurgical phase diagram of the combination of the constituent components. The invention is especially useful in the Li/FeS/sub 2/ system.

  17. Estimation of freshwater availability in the West African sub-continent using the SWAT hydrologic

    E-Print Network [OSTI]

    Estimation of freshwater availability in the West African sub-continent using the SWAT hydrologic availability is indispensable for water resources management at regional or national level. This information processes. The currently available estimates of freshwater availability by a few large international

  18. Synthesis and characterization of (H{sub 2}dab){sub 2}Cu{sub 8}Ge{sub 4}S{sub 14}{center_dot}2H{sub 2}O: An expanded framework based on icosahedral Cu{sub 8}S{sub 12} cluster

    SciTech Connect (OSTI)

    Zhang Renchun; Zhang Chi [Department of Chemistry, Dalian University of Technology, Dalian 116024 (China); Ji Shouhua [Department of Materials, Dalian University of Technology, Dalian 116024 (China); Ji Min [Department of Chemistry, Dalian University of Technology, Dalian 116024 (China); An Yonglin, E-mail: ylan@dlut.edu.cn [Department of Chemistry, Dalian University of Technology, Dalian 116024 (China)

    2012-02-15

    A new three-dimensional framework copper-thiogermanate, (H{sub 2}dab){sub 2}Cu{sub 8}Ge{sub 4}S{sub 14}{center_dot}2H{sub 2}O (1), was prepared under solvothermal condition and characterized by elemental analysis, single-crystal and powder X-ray diffraction, thermogravimetric analysis and UV-vis diffuse reflectance spectroscopy. Compound 1 crystallizes in the monoclinic space group P2(1)/c, a=11.444(4) A, b=12.984(4) A, c=12.455(6) A, {beta}=91.527(1) Degree-Sign , V=1850.2(3) A{sup 3}, Z=2. It contains a new three-dimensional Cu-Ge-S framework constructed from icosahedral [Cu{sub 8}S{sub 12}]{sup 16-} clusters linked by [GeS{sub 4}]{sup 4-} and dimeric [Ge{sub 2}S{sub 6}]{sup 4-} units, with diprotonated 1,4-dab (1,4-diaminobutane) and H{sub 2}O molecules located in the intersecting channels. UV-vis reflectance spectroscopy reveals the band gap of compound 1 is 2.5 eV. - Graphical abstract: Compound 1 contains a 3D expanded framework constructed from icosahedral Cu{sub 8}S{sub 12} clusters linked by GeS{sub 4} and dimeric Ge{sub 2}S{sub 6} units, with diprotonated 1,4-dab and H{sub 2}O molecules located in the channels. Highlights: Black-Right-Pointing-Pointer A new 3-D framework copper-thiogermanate was prepared under solvothermal condition. Black-Right-Pointing-Pointer The framework is built up from icosahedral Cu{sub 8}S{sub 12} clusters linked by GeS{sub 4} and dimeric Ge{sub 2}S{sub 6} units. Black-Right-Pointing-Pointer The result provides a new strategy to expand octahedral SBUs-based framework. Black-Right-Pointing-Pointer Compound 1 is a semiconductor with the band gap of 2.5 eV.

  19. The enhanced spontaneous dielectric polarization in Ga doped CuFeO{sub 2}

    SciTech Connect (OSTI)

    Shi, Liran; Wei, Meng; Huang, Junwei; Chen, Borong; Shang, Cui [Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074 (China); School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); Xia, Zhengcai, E-mail: xia9020@mail.hust.edu.cn; Long, Zhuo; Ouyang, Zhongwen; Xia, Nianming [Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2014-11-07

    The magnetic and dielectric polarization properties of the single crystal samples of CuFe{sub 1?x}Ga{sub x}O{sub 2} (x?=?0 and 0.02) are investigated. Experimental results show that the magnetization and dielectric polarizations are anisotropy and coupled together. Compared with pure CuFeO{sub 2}, in the case with the magnetic field parallel to the c axis, a field-induced phase transition with a hysteresis is clearly observed between the five-sublattice (5SL) and three-sublattice (3SL) phases. Specially, an obvious spontaneous dielectric polarization is observed in CuFe{sub 0.98}Ga{sub 0.02}O{sub 2} in a lower magnetic field region, indicating that the Ga doping has an effect on the enhancement of spontaneous dielectric polarization. Based on the dilution effect, change of exchange interaction, and partial release of the spin frustration due to the structural modulation of the Ga ion dopant, the origin of the magnetization, and spontaneous polarization characteristics are discussed and the complete dielectric polarization diagrams are assumed.

  20. WEST COAST REGIONAL CARBON SEQUESTRATION PARTNERSHIP

    SciTech Connect (OSTI)

    Larry Myer; Terry Surles; Kelly Birkinshaw

    2004-01-01

    The West Coast Regional Carbon Sequestration Partnership is one of seven partnerships which have been established by the US Department of Energy (DOE) to evaluate carbon dioxide capture, transport and sequestration (CT&S) technologies best suited for different regions of the country. The West Coast Region comprises Arizona, California, Nevada, Oregon, Washington, and the North Slope of Alaska. Led by the California Energy Commission, the West Coast Partnership is a consortium of over thirty five organizations, including state natural resource and environmental protection agencies; national labs and universities; private companies working on CO{sub 2} capture, transportation, and storage technologies; utilities; oil and gas companies; nonprofit organizations; and policy/governance coordinating organizations. In an eighteen month Phase I project, the Partnership will evaluate both terrestrial and geologic sequestration options. Work will focus on five major objectives: (1) Collect data to characterize major CO{sub 2} point sources, the transportation options, and the terrestrial and geologic sinks in the region, and compile and organize this data via a geographic information system (GIS) database; (2) Address key issues affecting deployment of CT&S technologies, including storage site permitting and monitoring, injection regulations, and health and environmental risks (3) Conduct public outreach and maintain an open dialogue with stakeholders in CT&S technologies through public meetings, joint research, and education work (4) Integrate and analyze data and information from the above tasks in order to develop supply curves and cost effective, environmentally acceptable sequestration options, both near- and long-term (5) Identify appropriate terrestrial and geologic demonstration projects consistent with the options defined above, and create action plans for their safe and effective implementation A kickoff meeting for the West Coast Partnership was held on Sept 30-Oct.1. Contracts were then put into place with twelve organizations which will carry out the technical work required to meet Partnership objectives.

  1. Control of bootstrap current in the pedestal region of tokamaks

    SciTech Connect (OSTI)

    Shaing, K. C. [Institute for Space and Plasma Sciences, National Cheng Kung University, Tainan City 70101, Taiwan (China) [Institute for Space and Plasma Sciences, National Cheng Kung University, Tainan City 70101, Taiwan (China); Department of Engineering Physics, University of Wisconsin, Madison, Wisconsin 53796 (United States); Lai, A. L. [Institute for Space and Plasma Sciences, National Cheng Kung University, Tainan City 70101, Taiwan (China)] [Institute for Space and Plasma Sciences, National Cheng Kung University, Tainan City 70101, Taiwan (China)

    2013-12-15

    The high confinement mode (H-mode) plasmas in the pedestal region of tokamaks are characterized by steep gradient of the radial electric field, and sonic poloidal U{sub p,m} flow that consists of poloidal components of the E×B flow and the plasma flow velocity that is parallel to the magnetic field B. Here, E is the electric field. The bootstrap current that is important for the equilibrium, and stability of the pedestal of H-mode plasmas is shown to have an expression different from that in the conventional theory. In the limit where ?U{sub p,m}?? 1, the bootstrap current is driven by the electron temperature gradient and inductive electric field fundamentally different from that in the conventional theory. The bootstrap current in the pedestal region can be controlled through manipulating U{sub p,m} and the gradient of the radial electric. This, in turn, can control plasma stability such as edge-localized modes. Quantitative evaluations of various coefficients are shown to illustrate that the bootstrap current remains finite when ?U{sub p,m}? approaches infinite and to provide indications how to control the bootstrap current. Approximate analytic expressions for viscous coefficients that join results in the banana and plateau-Pfirsch-Schluter regimes are presented to facilitate bootstrap and neoclassical transport simulations in the pedestal region.

  2. A NEW CATALOG OF H II REGIONS IN M31

    SciTech Connect (OSTI)

    Azimlu, M.; Marciniak, R.; Barmby, P.

    2011-10-15

    We present a new catalog of H II regions in M31. The full disk of the galaxy ({approx}24 kpc from the galaxy center) is covered in a 2.2 deg{sup 2} mosaic of 10 fields observed with the Mosaic Camera on the Mayall 4 m telescope as part of the Local Group Galaxies survey. We used HIIphot, a code for automated photometry of H II regions, to identify the regions and measure their fluxes and sizes. A 10{sigma} detection level was used to exclude diffuse gas fluctuations and star residuals after continuum subtraction. That selection limit may result in missing some faint H II regions, but our catalog of 3691 H II regions is still complete to a luminosity of L{sub H{alpha}} = 10{sup 34} erg s{sup -1}. This is five times fainter than the only previous CCD-based study which contained 967 objects in the NE half of M31. We determined the H{alpha} luminosity function (LF) by fitting a power law to luminosities larger than L{sub H{alpha}} = 10{sup 36.7} and determined a slope of 2.52 {+-} 0.07. The in-arm and inter-arm LFs peak at different luminosities but they have similar bright-end slopes. The inter-arm regions are less populated (40% of total detected regions) and constitute only 14% of the total luminosity of L{sub H{alpha}} = 5.6 x 10{sup 40} erg s{sup -1} (after extinction correction and considering 65% contribution from diffused ionized gas). A star formation rate of 0.44 M{sub sun} yr{sup -1} was estimated from the H{alpha} total luminosity; this value is consistent with the determination from the Spitzer 8 {mu}m image. We removed all known and potential planetary nebulae, yet we found a double-peaked LF. The inter-arm older population suggests a starburst between 15 and 20 million years ago. This result is in agreement with UV studies of the star formation history in M31 which found a star formation rate decrease in the recent past. We found a fair spatial correlation between the H II regions and stellar clusters in selected star-forming regions. Most of the matched regions lie within the arm regions.

  3. Electric-field induced strain modulation of magnetization in Fe-Ga/Pb(Mg{sub 1/3}Nb{sub 2/3})-PbTiO{sub 3} magnetoelectric heterostructures

    SciTech Connect (OSTI)

    Zhang, Yue Wang, Zhiguang; Wang, Yaojin; Luo, Chengtao; Li, Jiefang; Viehland, Dwight

    2014-02-28

    Magnetostrictive Fe-Ga thin layers were deposited on ?110?-oriented Pb(Mg{sub 1/3}Nb{sub 2/3})-30%PbTiO{sub 3} (PMN-30%PT) substrates by pulsed laser deposition. The as-prepared heterostructures showed columnar arrays aligned in the out-of-plane direction. Transmission electron microscopy revealed nanocrystalline regions within the columnar arrays of the Fe-Ga film. The heterostructure exhibited a strong converse magnetoelectric coupling effect of up to 4.55?×?10{sup ?7} s m{sup ?1}, as well as an electric field tunability of the in-plane magnetic anisotropy. Furthermore, the remanent magnetization states of the Fe-Ga films can be reversibly and irreversibly changed by external electric fields, suggesting a promising and robust application in magnetic random access memories and spintronics.

  4. Crystal structure of Mn{sub 2}Ln{sub 3}Sb{sub 3}O{sub 14} (Ln=La, Pr and Nd): A new ordered rhombohedral pyrochlore

    SciTech Connect (OSTI)

    Fu, W.T., E-mail: w.fu@chem.leidenuniv.nl; IJdo, D.J.W.

    2014-05-01

    Manganese rare earth antimonates with the formula Mn{sub 2}Ln{sub 3}Sb{sub 3}O{sub 14} (Ln=La–Yb and Y) have been prepared and their structures were determined by the Rietveld method using X-ray diffraction data. The compounds with Ln=La, Pr and Nd crystallize in a rhombohedral supercell of the cubic fluorite with the space group R3{sup ¯}m and with the lattice parameters a{sub h}??2a{sub c} and c{sub h}?2?3a{sub c}, where a{sub c} denotes the lattice constant of the cubic fluorite. The structure is pyrochlore-like but differs from the common cubic pyrochlore A{sub 2}B{sub 2}O{sub 7} in that it consists of fully ordered Mn:Ln in the A sites and Mn:Sb in the B sites with the ratio 1:3. The most interesting feature of Mn{sub 2}Ln{sub 3}Sb{sub 3}O{sub 14} is that the divalent Mn ions have different coordination numbers with oxygen and the Mn(II)O{sub 6} (octahedron) and Mn(II)O{sub 8} (hexagonal bipyramid) alternate along the parent cubic fluorite axes. For medium sized lanthanides, i.e. from Ln=Sm, the rhombohedral phase coexists with the cubic phase and Mn{sub 2}Y{sub 3}Sb{sub 3}O{sub 14} is cubic a pyrochlore. - Graphical abstract: Crystal structure of rhombohedral pyrochlore Mn{sub 2}Ln{sub 3}Sb{sub 3}O{sub 14} (Ln=La, Pr, and Nd) showing the staking of Ln{sub 3}Mn and MnSb{sub 3} layers (a). (b) and (c) show the connections between Mn1O{sub 6} and LnO{sub 8} and between Mn2O{sub 8} and SbO{sub 6} polyhedra, respectively. - Highlights: • Pyrochlores of the formula Mn{sub 2}Ln{sub 3}Sb{sub 3}O{sub 14} (Ln=La–Yb and Y) were synthesized for the first time. • Mn{sub 2}Ln{sub 3}Sb{sub 3}O{sub 14} with Ln=La, Pr, Nd are rhombohedral consisting of fully 1:3 ordering of metal ions. • With medium-sized Ln, rhombohedral phase co-exists with cubic phase. • Two divalent Mn ions have coordination numbers of 6 and 8, respectively.

  5. Influence of H{sub 2}O{sub 2} on LPG fuel performance evaluation

    SciTech Connect (OSTI)

    Khan, Muhammad Saad Ahmed, Iqbal Mutalib, Mohammad Ibrahim bin Abdul Nadeem, Saad Ali, Shahid

    2014-10-24

    The objective of this mode of combustion is to insertion of hydrogen peroxide (H{sub 2}O{sub 2}) to the Liquefied Petroleum Gas (LPG) combustion on spark plug ignition engines. The addition of hydrogen peroxide may probably decrease the formation of NO{sub x}, CO{sub x} and unburned hydrocarbons. Hypothetically, Studies have shown that addition of hydrogen peroxide to examine the performance of LPG/H{sub 2}O{sub 2} mixture in numerous volumetric compositions starting from lean LPG until obtaining a better composition can reduce the LPG fuel consumption. The theory behind this idea is that, the addition of H{sub 2}O{sub 2} can cover the lean operation limit, increase the lean burn ability, diminution the burn duration along with controlling the exhaust emission by significantly reducing the greenhouse gaseous.

  6. Factorized power expansion for high-p<sub>T> heavy quarkonium production

    SciTech Connect (OSTI)

    Ma, Yan-Qing; Qiu, Jian-Wei; Sterman, George; Zhang, Hong

    2014-10-02

    We show that when the factorized cross section for heavy quarkonium production includes next-to-leading power contributions associated with the production of the heavy quark pair at short distances, it naturally reproduces all high p<sub>T> results calculated in nonrelativistic QCD (NRQCD) factorization. This extended formalism requires fragmentation functions for heavy quark pairs, as well as for light partons. When these fragmentation functions are themselves calculated using NRQCD, we find that two of the four leading NRQCD production channels, ³S[1]<sub>1sub> and ¹S[8]<sub>0sub>, are dominated by the next-to-leading power contributions for a very wide p<sub>T> range. The large next-to-leading order corrections of NRQCD are absorbed into the leading order of the first power correction. The impact of this finding on heavy quarkonium production and its polarization is discussed.

  7. Proton and Ion Acceleration by BNL Terewatt Picosecond CO<sub>2sub> Laser. New Horizons

    SciTech Connect (OSTI)

    Shkolnikov, Peter

    2014-09-30

    The report covers pioneering research on proton and ion generation in gas jets by the world's first picosecond TW CO<sub>2sub> laser developed at Brookhaven National Laboratory

  8. CO<sub>2sub> Binding Organic Liquids Gas Capture with Polarity Swing Assisted Regeneration

    SciTech Connect (OSTI)

    Heldebrant, David

    2014-05-31

    This report outlines the comprehensive bench-scale testing of the CO<sub>2sub>-binding organic liquids (CO<sub>2sub>BOLs) solvent platform and its unique Polarity Swing Assisted Regeneration (PSAR). This study outlines all efforts on a candidate CO<sub>2sub>BOL solvent molecule, including solvent synthesis, material characterization, preliminary toxicology studies, and measurement of all physical, thermodynamic and kinetic data, including bench-scale testing. Equilibrium and kinetic models and analysis were made using Aspen Plus™. Preliminary process configurations, a technoeconomic assessment and solvent performance projections for separating CO<sub>2sub> from a subcritical coal-fired power plant are compared to the U.S. Department of Energy's Case 10 monoethanolamine baseline.

  9. Yb:(YLa){sub 2}O{sub 3} laser ceramics produced by microwave sintering

    SciTech Connect (OSTI)

    Balabanov, S S; Bykov, Yu V; Egorov, S V; Eremeev, A G; Gavrishchuk, E M; Khazanov, Efim A; Mukhin, I B; Palashov, O V; Permin, D A; Zelenogorskii, V V

    2013-04-30

    The possibility of using microwave heating for sintering of optical oxide ceramics and the advantages of this method are considered. Sintering of Yb{sub 0.1}:(YLa){sub 1.9}O{sub 3} ceramics by heating with 24-GHz radiation is studied. The compacts for sintering are prepared from nanosized powders obtained by high-temperature synthesis from acetate-nitrates of rare-earth metals. The effect of addition of lanthanum oxide and of the uniaxial pressing conditions on the microstructure and optical transmission of ceramics is studied. Lasing at a wavelength of 1030 nm with an efficiency of 7.5 % is achieved in ceramic samples of the (Yb{sub 0.05}Y{sub 0.1}La{sub 0.85}){sub 2}O{sub 3} composition under pumping by a laser diode at a wavelength of 940 nm. (extreme light fields and their applications)

  10. A partonic interpretation of DVCS at small x{sub B{sub j}}

    SciTech Connect (OSTI)

    Kumericki, Kresimir; Mueller, Dieter; Passek-Kumericki, Kornelija

    2009-03-23

    We describe small-X{sub B{sub j}} deeply virtual Compton scattering measurements at HERA in terms of generalized parton distributions at leading order of perturbation series.

  11. Factorized power expansion for high-p<sub>T> heavy quarkonium production

    SciTech Connect (OSTI)

    Ma, Yan-Qing [Brookhaven National Laboratory, Physics Department, Upton, NY (United States); Qiu, Jian-Wei [Brookhaven National Laboratory, Physics Department, Upton, NY (United States); Stony Brook University, C.N. Yang Institute for Theoretical Physics, Department of Physics and Astronomy, Stony Brook, NY (United States); Sterman, George [Stony Brook University, C.N. Yang Institute for Theoretical Physics, Department of Physics and Astronomy, Stony Brook, NY (United States); Zhang, Hong [Stony Brook University, Department of Physics and Astronomy, Stony Brook, NY (United States)

    2014-10-01

    We show that when the factorized cross section for heavy quarkonium production includes next-to-leading power contributions associated with the production of the heavy quark pair at short distances, it naturally reproduces all high p<sub>T> results calculated in nonrelativistic QCD (NRQCD) factorization. This extended formalism requires fragmentation functions for heavy quark pairs, as well as for light partons. When these fragmentation functions are themselves calculated using NRQCD, we find that two of the four leading NRQCD production channels, ³S[1]<sub>1sub> and ¹S[8]<sub>0sub>, are dominated by the next-to-leading power contributions for a very wide p<sub>T> range. The large next-to-leading order corrections of NRQCD are absorbed into the leading order of the first power correction. The impact of this finding on heavy quarkonium production and its polarization is discussed.

  12. Optical absorption in epitaxial La{sub 1-x}Sr{sub x}FeO{sub 3} thin films

    SciTech Connect (OSTI)

    Scafetta, M D.; Xie, Y. J.; Torres, M.; Spanier, J. E.; May, S. J.

    2013-02-25

    We report the dependence of optical absorption on Sr concentration in La{sub 1-x}Sr{sub x}FeO{sub 3} (LSFO) (x{<=}0.4) perovskite thin films. Strained epitaxial films were deposited on SrTiO{sub 3} substrates using oxide molecular beam epitaxy. We find systematic changes in the optical absorption spectra with increasing x including a red-shift of transition energies and the increasing presence of a lower energy transition within the fundamental gap of pure LaFeO{sub 3}. These results serve as a demonstration of the complex manner in which absorption spectra can be altered in complex oxides via heterovalent A-site substitution.

  13. Electronic phase diagram of epitaxial La{sub 1?x}Sr{sub x}FeO{sub 3} films

    SciTech Connect (OSTI)

    Xie, Y. J.; Scafetta, M. D.; Moon, E. J.; Krick, A. L.; Sichel-Tissot, R. J.; May, S. J.

    2014-08-11

    The electronic phase diagram of epitaxial La{sub 1?x}Sr{sub x}FeO{sub 3} films is presented. The films were grown on SrTiO{sub 3} using molecular beam epitaxy with post-growth annealing to minimize oxygen vacancies. Insulating behavior is observed from x?=?0–0.9, with metallic conduction only present for x?=?1.0. While the La-rich compounds exhibit polaron conduction over all temperatures measured, the Sr-rich films exhibit an electronic phase transition within the compositional window of x?=?0.49–0.9 as revealed by temperature-dependent resistivity measurements. The transition temperatures are found to decrease with increasing Sr content. The constructed phase diagram is discussed in the context of other 3d e{sub g} perovskite systems including manganites and cobaltites.

  14. Disorder-driven spin-reorientation in multiferroic h-YMn{sub 1?x}Fe{sub x}O{sub 3}

    SciTech Connect (OSTI)

    Namdeo, Sonu; Rao, S. S.; Awasthi, A. M.; Kaushik, S. D.; Siruguri, V.

    2014-07-14

    Magnetic structure evolution of multiferroic hexagonal YMn{sub 1?x}Fe{sub x}O{sub 3} (x?=?0, 0.05, and 0.1) has been studied by carrying out detailed temperature-dependent neutron diffraction at zero and 5?T fields. Thermodynamic data confirm antiferromagnetic ordering at T{sub N} in all the compositions. Our sub-T{sub N} neutron diffraction results assign the magnetic structure of pure YMnO{sub 3} to ?{sub 1} irreducible representation. Over the perturbative-doping range, magnetic structure changes via ?{sub 1}?+??{sub 2} for YMn{sub 0.95}Fe{sub 0.05}O{sub 3} on to ?{sub 2} for YMn{sub 0.9}Fe{sub 0.1}O{sub 3}, as the maiden compositional analogue of spin-reorientation; its occurrence in temperature-domain already reported for several manganites. Moreover, while the large thermal isostructural changes observed above T{sub N} are subdued in the ordered state, small alterations by the applied 5?T-field are relatively uniform across, confirming strong magneto-elastic nature of the system. Decrease of the ordered magnetic moment (?{sub ord}) and planar magnetic frustration noted with Fe-doping is enhanced by the applied field, apparently through canting.

  15. Crystal structure, magnetism and transport properties of Ce{sub 3}Ni{sub 25.75}Ru{sub 3.16}Al{sub 4.1}B{sub 10}

    SciTech Connect (OSTI)

    Janka, Oliver; Baumbach, Ryan E.; Thompson, Joe D.; Bauer, Eric D.; Kauzlarich, Susan M.

    2013-09-15

    Single crystals of Ce{sub 3}Ni{sub 25.75}Ru{sub 3.16}Al{sub 4.1}B{sub 10} were obtained from a process in which a polycrystalline sample of CeRu{sub 2}Al{sub 2}B was annealed in an excess of a Ni–In flux. The initial phase, CeRu{sub 2}Al{sub 2}B, does not recrystallize, instead, crystals of a new phase, Ce{sub 3}Ni{sub 25.75}Ru{sub 3.16}Al{sub 4.1}B{sub 10}, could be isolated once the flux was removed. The title compound crystallizes in the tetragonal space group P4/nmm (No. 129) with a=1139.02(8), c=801.68(6) pm (c/a=0.70) in the Nd{sub 3}Ni{sub 29}Si{sub 4}B{sub 10} structure type. Electrical resistivity measurements reveal metallic behavior with a minimum of 700 µ? cm and a small residual resistivity ratio of RRR=1.4 indicating a large amount of disorder scattering. The cerium atoms are either in the 4+ or an intermediate valence state with a valence fluctuation temperature far above room temperature. - Graphical abstract: Single crystals of Ce{sub 3}Ni{sub 25.75}Ru{sub 3.16}A{sub l4.1}B{sub 10} were obtained using a process in which a polycrystalline sample of CeRu{sub 2}Al{sub 2}B was annealed in an excess of a Ni–In flux. Electrical resistivity measurements reveal metallic behavior with a minimum of 700 ?? cm and a small residual resistivity ratio of RRR=1.4 indicating a large amount of disorder scattering. The cerium atoms are either in the 4+ or an intermediate valence state with a valence fluctuation temperature far above room temperature. Display Omitted - Highlights: • Flux synthesis of high quality single crystals of Ce{sub 3}Ni{sub 25.75}Ru{sub 3.16}Al{sub 4.1}B{sub 10} is presented along with the crystal structure, magnetic and transport properties. • The compound is isostructural to Nd{sub 3}Ni{sub 29}Si{sub 4}B{sub 10} but is first of this structure type showing mixed occupancies of d-elements. • This is an intermetallic phase with Ce in either the 4+ or an intermediate valence state. • The fact that this structure with mixed occupied transition metal sites exists suggests that more compounds of this type should be accessible and the physical properties tuned.

  16. Local structure and disorder in crystalline Pb{sub 9}Al{sub 8}O{sub 21}

    SciTech Connect (OSTI)

    Hannon, Alex C. Barney, Emma R.; Holland, Diane; Knight, Kevin S.

    2008-05-15

    Crystalline Pb{sub 9}Al{sub 8}O{sub 21} is a model compound for the structure of non-linear optical glasses containing lone-pair ions, and its structure has been investigated by neutron powder diffraction and total scattering, and {sup 27}Al magic angle spinning NMR. Rietveld analysis (space group Pa3-bar (No. 205), a=13.25221(4) A) shows that some of the Pb and O sites have partial occupancies, due to lead volatilisation during sample preparation, and the non-stoichiometric sample composition is Pb{sub 9-{delta}}Al{sub 8}O{sub 21-{delta}} with {delta}=0.54. The NMR measurements show evidence for a correlation between the chemical shift and the variance of the bond angles at the aluminium sites. The neutron total correlation function shows that the true average Al-O bond length is 0.8% longer than the apparent bond length determined by Rietveld refinement. The thermal variation in bond length is much smaller than the thermal variation in longer interatomic distances determined by Rietveld refinement. The total correlation function is consistent with an interpretation in which AlO{sub 3} groups with an Al-O bond length of 1.651 A occur as a result of the oxygen vacancies in the structure. The width of the tetrahedral Al-O peak in the correlation function for the crystal is very similar to that for lead aluminate glass, indicating that the extent of static disorder is very similar in the two phases. - Graphical abstract: Combined neutron powder diffraction and total scattering, and {sup 27}Al NMR on crystalline Pb{sub 9}Al{sub 8}O{sub 21} shows it to be a non-stoichiometric compound with vacancies due to PbO volatilisation. A detailed consideration of the thermal and static disorder is given, showing that glass and crystal phases have very similar disorder at short range.

  17. Doped Y.sub.2O.sub.3 buffer layers for laminated conductors

    DOE Patents [OSTI]

    Paranthaman, Mariappan Parans (Knoxville, TN) [Knoxville, TN; Schoop, Urs (Westborough, MA) [Westborough, MA; Goyal, Amit (Knoxville, TN) [Knoxville, TN; Thieme, Cornelis Leo Hans (Westborough, MA) [Westborough, MA; Verebelyi, Darren T. (Oxford, MA) [Oxford, MA; Rupich, Martin W. (Framingham, MA) [Framingham, MA

    2007-08-21

    A laminated conductor includes a metallic substrate having a surface, a biaxially textured buffer layer supported by the surface of the metallic substrate, the biaxially textured buffer layer comprising Y.sub.2O.sub.3 and a dopant for blocking cation diffusion through the Y.sub.2O.sub.3, and a biaxially textured conductor layer supported by the biaxially textured buffer layer.

  18. Full differentiation and assignment of boron species in the electrolytes Li{sub 2}B{sub 6}O{sub 9}F{sub 2} and Li{sub 2}B{sub 3}O{sub 4}F{sub 3} by solid-state {sup 11}B NMR spectroscopy

    SciTech Connect (OSTI)

    Braeuniger, Thomas; Pilz, Thomas; Chandran, C. Vinod; Jansen, Martin

    2012-10-15

    The syntheses of two new fluorooxoborates, Li{sub 2}B{sub 3}O{sub 4}F{sub 3} and Li{sub 2}B{sub 6}O{sub 9}F{sub 2}, which possess considerable ion conductivity at higher temperatures, have been reported recently. Here, we describe the characterisation of these compounds by solid-state {sup 11}B NMR spectroscopy. The complex central-transition MAS spectra, resulting from overlap of sub-spectra contributed by the individual boron species in the crystal structures, could be clearly separated by acquisition and analysis of 3QMAS spectra. By numerical fit of these sub-spectra, the isotropic chemical shift {delta}{sub iso}, the quadrupolar coupling constant {chi}, and the asymmetry {eta} were determined. Using known relations between boron coordination and chemical shift as well as quadrupolar coupling, the individual {sup 11}B NMR resonances have been ascribed to boron species in tetrahedral or trigonal environment. To remove remaining assignment ambiguities, the response of the {sup 11}B resonances to {sup 19}F decoupling was qualitatively analysed. Thus, by using the combined information conveyed by chemical shift, quadrupolar and dipolar interaction, a complete assignment of the complex {sup 11}B line shapes exhibited by the fluorooxoborates has been achieved. - Graphical abstract: Structure and solid-state {sup 11}B NMR spectrum of Li{sub 2}B{sub 3}O{sub 4}F{sub 3}. Highlights: Black-Right-Pointing-Pointer Characterisation of title compounds by solid-state {sup 11}B NMR spectroscopy. Black-Right-Pointing-Pointer Sub-spectra of boron species separated by evaluation of 3QMAS spectra. Black-Right-Pointing-Pointer Isotropic chemical shift and quadrupolar interaction parameters determined. Black-Right-Pointing-Pointer Full boron assignment based on NMR parameters and response to {sup 19}F decoupling.

  19. Method of forming a dielectric thin film having low loss composition of Ba.sub.x Sr.sub.y Ca.sub.1-x-y TiO.sub.3 : Ba.sub.0.12-0.25 Sr.sub.0.35-0.47 Ca.sub.0.32-0.53 TiO.sub.3

    DOE Patents [OSTI]

    Xiang, Xiao-Dong (Alameda, CA); Chang, Hauyee (Berkeley, CA); Takeuchi, Ichiro (Albany, CA)

    2000-01-01

    A dielectric thin-film material for microwave applications, including use as a capacitor, the thin-film comprising a composition of barium strontium calcium and titanium of perovskite type (Ba.sub.x Sr.sub.y Ca.sub.1-x-y)TiO.sub.3. Also provided is a method for making a dielectric thin film of that formula over a wide compositional range through a single deposition process.

  20. HELIOSHEATH MAGNETIC FIELDS BETWEEN 104 AND 113 AU IN A REGION OF DECLINING SPEEDS AND A STAGNATION REGION

    SciTech Connect (OSTI)

    Burlaga, L. F. [NASA Goddard Space Flight Center, Code 673, Greenbelt, MD 20771 (United States); Ness, N. F., E-mail: lburlagahsp@verizon.net, E-mail: nfnudel@yahoo.com [Institute for Astrophysics and Computational Sciences, Catholic University of America, Washington, DC 20064 (United States)

    2012-04-10

    We examine the relationships between the magnetic field and the radial velocity component V{sub R} observed in the heliosheath by instruments on Voyager 1 (V1). No increase in the magnetic field strength B was observed in a region where V{sub R} decreased linearly from 70 km s{sup -1} to 0 km s{sup -1} as plasma moved outward past V1. An unusually broad transition from positive to negative polarity was observed during a Almost-Equal-To 26 day interval when the heliospheric current sheet (HCS) moved below the latitude of V1 and the speed of V1 was comparable to the radial speed of the heliosheath flow. When V1 moved through a region where V{sub R} Almost-Equal-To 0 (the 'stagnation region'), B increased linearly with time by a factor of two, and the average of B was 0.14 nT. Nothing comparable to this was observed previously. The magnetic polarity was negative throughout the stagnation region for Almost-Equal-To 580 days until 2011 DOY 235, indicating that the HCS was below the latitude of V1. The average passage times of the magnetic holes and proton boundary layers were the same during 2009 and 2011, because the plasma moved past V1 during 2009 at the same speed that V1 moved through the stagnation region during 2011. The microscale fluctuations of B in the stagnation region during 2011 are qualitatively the same as those observed in the heliosheath during 2009. These results suggest that the stagnation region is a part of the heliosheath, rather than a 'transition region' associated with the heliopause.