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Sample records for riv er ba

  1. Magnetic and dielectric behavior of the spin-chain compound Er?BaNiO? well below its Nel temperature

    SciTech Connect (OSTI)

    Basu, Tathamay; Singh, Kiran; Sampathkumaran, E. V.; Mohapatra, N.

    2014-09-21

    We have recently reported that the Haldane spin-chain system, Er?BaNiO?, undergoing antiferromagnetic order below (T{sub N}=) 32 K, is characterized by the onset of ferroelectricity near 60 K due to magnetoelectric coupling induced by short-range magnetic-order within spin-chains. We have carried out additional magnetic and dielectric studies to understand the properties well below T{sub N}. We emphasize here on the following: (i) A strong frequency dependent behaviors of ac magnetic susceptibility and complex dielectric properties have been observed at much lower temperatures (<8 K), that is, reentrant multiglass-like phenomenon, naturally suggesting the existence of an additional transition well below T{sub N}. (ii) Magnetoelectric phase coexistence is observed at very low temperature (e.g., T=2 K), where the high-field magnetoelectric phase is partially arrested on returning to zero magnetic field after a cycling through metamagnetic transition.

  2. ORPC RivGen controller performance raw data - Igiugig 2015

    SciTech Connect (OSTI)

    Jarlath McEntee

    2015-12-18

    Contains raw data for operations of Ocean Renewable Power Company (ORPC) RivGen Power System in Igiugig 2015 in Matlab data file format. Two data files capture the data and timestamps for data, including power in, voltage, rotation rate, and velocity.

  3. Bifunction in Er{sup 3+}/Yb{sup 3+} co-doped BaTi{sub 2}O{sub 5}Gd{sub 2}O{sub 3} glasses prepared by aerodynamic levitation method

    SciTech Connect (OSTI)

    Zhang, Minghui; Yu, Jianding; Pan, Xiuhong; Cheng, Yuxing; Liu, Yan

    2013-11-15

    Graphical abstract: - Highlights: Novel BaTi{sub 2}O{sub 5}Gd{sub 2}O{sub 3} based glasses have been prepared by aerodynamic levitation. The obtained glasses show high thermal stability with T{sub g} = 763.3 C. Er{sup 3+}/Yb{sup 3+} co-doped glasses show strong upconversion based on a two-photon process. Red emission is stronger than green emissions for EBT by high Yb{sup 3+} concentration. Magnetic ions are paramagnetic and the distribution is homogeneous in the glasses. - Abstract: Novel Er{sup 3+}/Yb{sup 3+} co-doped BaTi{sub 2}O{sub 5}Gd{sub 2}O{sub 3} spherical glasses have been fabricated by aerodynamic levitation method. The thermal stability, upconversion luminescence, and magnetic properties of the present glass have been studied. The glasses show high thermal stability with 763.3 C of the onset temperature of the glass transition. Red and green emissions centered at 671 nm, 548 nm and 535 nm are obtained at 980 nm excitation. The upconversion is based on a two-photon process by energy transfer, excited-state absorption, and energy back transfer. Yb{sup 3+} ions are more than Er{sup 3+} ions in the glass, resulting in efficient energy back transfer from Er{sup 3+} to Yb{sup 3+}. So the red emission is stronger than the green emissions. Magnetization curves indicate that magnetic rare earth ions are paramagnetic and the distribution is homogeneous and random in the glass matrix. Aerodynamic levitation method is an efficient way to prepare glasses with homogeneous rare earth ions.

  4. Protein folding in the ER.

    SciTech Connect (OSTI)

    Stevens, F. J.; Argon, Y.; Biosciences Division; Univ. of Chicago

    1999-10-01

    The endoplasmic reticulum (ER) is a major protein folding compartment for secreted, plasma membrane and organelle proteins. Each of these newly-synthesized polypeptides folds in a deterministic process, affected by the unique conditions that exist in the ER. An understanding of protein folding in the ER is a fundamental biomolecular challenge at two levels. The first level addresses how the amino acid sequence programs that polypeptide to efficiently arrive at a particular fold out of a multitude of alternatives, and how different sequences obtain similar folds. At the second level are the issues introduced by folding not in the cytosol, but in the ER, including the risk of aggregation in a molecularly crowded environment, accommodation of post-translational modifications and the compatibility with subsequent intracellular trafficking. This review discusses both the physicochemical and cell biological constraints of folding, which are the challenges that the ER molecular chaperones help overcome.

  5. Electronic state of Er in sputtered AlN:Er films determined by magnetic measurements

    SciTech Connect (OSTI)

    Narang, V.; Seehra, M. S.; Korakakis, D.

    2014-12-07

    The optoelectronic and piezoelectric properties of AlN:Er thin films have been of great recent interest for potential device applications. In this work, the focus is on the electronic state of Er in AlN:Er thin films prepared by reactive magnetron sputtering on (001) p-type Si substrate. X-ray diffraction shows that Er doping expands the lattice and the AlN:Er film has preferential c-plane orientation. To determine whether Er in AlN:Er is present as Er metal, Er{sub 2}O{sub 3}, or Er{sup 3+} substituting for Al{sup 3+}, detailed measurements and analysis of the temperature dependence (2 K–300 K) of the magnetization M at a fixed magnetic field H along with the M vs. H data at 2 K up to H = 90 kOe are presented. The presence of Er{sub 2}O{sub 3} and Er metal is ruled out since their characteristic magnetic transitions are not observed in the AlN:Er sample. Instead, the observed M vs. T and M vs. H variations are consistent with Er present as Er{sup 3+} substituting for Al{sup 3+} in AlN:Er at a concentration x = 1.08% in agreement with x = 0.94% ± 0.20% determined using x-ray photoelectron spectroscopy (XPS). The larger size of Er{sup 3+} vs. Al{sup 3+}explains the observed lattice expansion of AlN:Er.

  6. Ternary Dy-Er-Al magnetic refrigerants

    DOE Patents [OSTI]

    Gschneidner, Jr., Karl A.; Takeya, Hiroyuki

    1995-07-25

    A ternary magnetic refrigerant material comprising (Dy.sub.1-x Er.sub.x)Al.sub.2 for a magnetic refrigerator using the Joule-Brayton thermodynamic cycle spanning a temperature range from about 60K to about 10K, which can be adjusted by changing the Dy to Er ratio of the refrigerant.

  7. Ternary Dy-Er-Al magnetic refrigerants

    DOE Patents [OSTI]

    Gschneidner, K.A. Jr.; Takeya, Hiroyuki

    1995-07-25

    A ternary magnetic refrigerant material comprising (Dy{sub 1{minus}x}Er{sub x})Al{sub 2} for a magnetic refrigerator using the Joule-Brayton thermodynamic cycle spanning a temperature range from about 60K to about 10K, which can be adjusted by changing the Dy to Er ratio of the refrigerant. 29 figs.

  8. Materials Data on BaErCuS3 (SG:63) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  9. Sub-10 nm lanthanide doped BaLuF{sub 5} nanocrystals: Shape controllable synthesis, tunable multicolor emission and enhanced near-infrared upconversion luminescence

    SciTech Connect (OSTI)

    Rao, Ling; Lu, Wei; Wang, Haibo; Yi, Zhigao; Zeng, Songjun; Li, Zheng

    2015-04-15

    Highlights: • Sub-10 nm cubic phase BaLuF{sub 5} nanocrystals were synthesized by a hydrothermal method for the first time. • Tunable multicolor from yellow to yellow-green was achieved by controlling Gd{sup 3+} content in BaLuF{sub 5}:Yb/Er system. • Intense near-infrared upconversion luminescence in BaLuF{sub 5}:Gd/Yb/Tm nanocrystal. • The enhancement near-infrared luminescence can be realized by adjusting the content of Gd{sup 3+} in BaLuF{sub 5}:Gd/Yb/Tm system. - Abstract: In this study, sub-10 nm BaLuF{sub 5} nanocrystals with cubic phase structure were synthesized by a solvothermal method using oleic acid as the stabilizing agent. The as-prepared BaLuF{sub 5} nanocrystals were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and analyzed by the upconversion (UC) spectra. The TEM results reveal that these samples present high uniformity. Compared with Gd-free samples, the size of BaLuF{sub 5}:Yb/Er doped with 10% Gd{sup 3+} decreased to 5.6 nm. In addition, BaLuF{sub 5}:Yb/Tm/Gd upconversion nanoparticles (UCNPs) presented efficient near-infrared (NIR)-NIR UC luminescence. Therefore, it is expected that these ultra-small BaLuF{sub 5} nanocrystals with well-controlled shape, size, and UC emission have potential applications in biomedical imaging fields.

  10. Environmental release summary (ERS) database CY 1997

    SciTech Connect (OSTI)

    Gleckler, B.P.

    1998-07-01

    This report discusses the Environmental Release Summary (ERS) database. The current needs of the Effluent and Environmental database is continually modified to fulfill monitoring (EEM) program (managed by Waste Management Federal Services of Hanford, Incorporated, Air and Water Services Organization). Changes are made to accurately calculate current releases, to affect how past releases are calculated. This document serves as a snap-shot of the database and software for the CY-1997 data and releases. This document contains all of the relevant data for calculating radioactive-airborne and liquid effluent. The ERS database is the official repository for the CY-1997 ERS release reports and the settings used to generate those reports. As part of the Tri-Party Agreement, FDH is committed to provide a hard copy of the ERS database for Washington State Department of Ecology, upon request. This document also serves as that hard copy for the last complete calendar year.

  11. Ba{sub 2}phenanthrene is the main component in the Ba-doped phenanthrene superconductor

    SciTech Connect (OSTI)

    Yan, Xun-Wang; Huang, Zhongbing; Lin, Hai-Qing

    2014-12-14

    We have systematically investigated the crystal structure of Ba-doped phenanthrene with various Ba doping levels by the first-principles calculations combined with the X-ray diffraction (XRD) spectra simulations. Although the experimental stoichiometry ratio of Ba atom and phenanthrene molecule is 1.5:1, the simulated XRD spectra, space group symmetry and optimized lattice parameters of Ba{sub 1.5}phenanthrene are not consistent with the experimental ones, while the results for Ba{sub 2}phenanthrene are in good agreement with the measurements. The strength difference of a few XRD peaks can be explained by the existence of pristine phenanthrene. Our findings suggest that instead of uniform Ba{sub 1.5}phenanthrene, there coexist Ba{sub 2}phenanthrene and undoped phenanthrene in the superconducting sample. The electronic calculations indicate that Ba{sub 2}phenanthrene is a semiconductor with a small energy gap less than 0.05 eV.

  12. ErSol Thin Film GmbH formerly ErSol New Technologies GmbH ENT...

    Open Energy Info (EERE)

    ErSol Thin Film GmbH formerly ErSol New Technologies GmbH ENT Jump to: navigation, search Name: ErSol Thin Film GmbH (formerly ErSol New Technologies GmbH (ENT)) Place: Germany...

  13. ARM CLASIC ER2 CRS/EDOP

    SciTech Connect (OSTI)

    Gerald Heymsfield

    2010-12-20

    Data was taken with the NASA ER-2 aircraft with the Cloud Radar System and other instruments in conjunction with the DOE ARM CLASIC field campaign. The flights were near the SGP site in north Central Oklahoma and targeted small developing convection. The CRS is a 94 GHz nadir pointing Doppler radar. Also on board the ER-2 was the Cloud Physics Lidar (CPL). Seven science flights were conducted but the weather conditions did not cooperate in that there was neither developing convection, or there was heavy rain.

  14. Low temperature properties of some Er-rich intermetallic compounds

    SciTech Connect (OSTI)

    K.A. Gshneidner,jr; A.O. Pecharsky; L.Hale; V.K. Pecharsky

    2004-09-30

    The low temperature volumetric heat capacity ({approx}3.5 to 350 K) and magnetic susceptibility ({approx}4 to 320 K) of Er{sub 3}Rh, Er{sub 3}Ir, Er{sub 3}Pt, Er{sub 2}Al, and Er{sub 2}Sn have been measured. All of the compounds order antiferromagnetically (or ferrimagnetically), and most exhibit more than one magnetic ordering transition. The volumetric heat capacities in general are smaller than those of the prototype magnetic regenerator materials, except for Er{sub 3}Ir in the 12 to 14 K temperature range.

  15. DOE-ER-STD-6001-92

    Office of Energy Efficiency and Renewable Energy (EERE)

    Implementation Guide for Quality Assurance Programs for Basic and Applied Research Canceled (January, 2003) This Implementation Guide is intended to assist management at DOE-ER sponsored facilities in the process of developing and implementing Quality Assurance Programs (QAPs) that satisfy the requirements of DOE Order 5700.6C.

  16. ER-12-1 completion report

    SciTech Connect (OSTI)

    Russell, C.E.; Gillespie, D.; Cole, J.C.; Drellack, S.L.

    1996-12-01

    The objective of drillhole ER-12-1 was to determine the hydrogeology of paleozoic carbonate rocks and of the Eleana Formation, a regional aquitard, in an area potentially downgradient from underground nuclear testing conducted in nearby Rainier Mesa. This objective was addressed through the drilling of well ER-12-1 at N886,640.26 E640,538.85 Nevada Central Coordinates. Drilling of the 1094 m (3588 ft) well began on July 19, 1991 and was completed on October 17, 1991. Drilling problems included hole deviation and hole instability that prevented the timely completion of this borehole. Drilling methods used include rotary tri-cone and rotary hammer drilling with conventional and reverse circulation using air/water, air/foam (Davis mix), and bentonite mud. Geologic cuttings and geophysical logs were obtained from the well. The rocks penetrated by the ER-12-1 drillhole are a complex assemblage of Silurian, Devonian, and Mississippian sedimentary rocks that are bounded by numerous faults that show substantial stratigraphic offset. The final 7.3 m (24 ft) of this hole penetrated an unusual intrusive rock of Cretaceous age. The geology of this borehole was substantially different from that expected, with the Tongue Wash Fault encountered at a much shallower depth, paleozoic rocks shuffled out of stratigraphic sequence, and the presence of an altered biotite-rich microporphyritic igneous rock at the bottom of the borehole. Conodont CAI analyses and rock pyrolysis analyses indicate that the carbonate rocks in ER-12-1, as well as the intervening sheets of Eleana siltstone, have been thermally overprinted following movement on the faults that separate them. The probable source of heat for this thermal disturbance is the microporphyritic intrusion encountered at the bottom of the hole, and its age establishes that the major fault activity must have occurred prior to 102.3+0.5 Ma (middle Cretaceous).

  17. On the Use of an ER-213 Detonator to Establish a Baseline for the ER-486

    SciTech Connect (OSTI)

    Thomas, Keith A.; Liechty, Gary H.; Jaramillo, Dennis C.; Munger, Alan C.; McHugh, Douglas C.; Kennedy, James E.

    2014-08-19

    This report documents a series of tests using a TSD-115 fireset coupled with an ER-213, a gold exploding bridgewire (EBW) detonator. These tests were designed to fire this EBW with a smaller fireset to obtain current and voltage data as well as timing information at voltage levels below, above, and throughout the threshold firing region. This study could then create a database for comparison to our current ER-486 EBW development, which is designed to be a lower voltage (<500V) device.

  18. Dali Yang er Hydropower Development Co Ltd | Open Energy Information

    Open Energy Info (EERE)

    Yang er Hydropower Development Co Ltd Jump to: navigation, search Name: Dali Yanger Hydropower Development Co Ltd Place: Dali Prefecture, Dali, Yunnan Province, China Zip: 625000...

  19. Final Technical Report for Award # ER64999

    SciTech Connect (OSTI)

    Metcalf, William W.

    2014-10-08

    This report provides a summary of activities for Award # ER64999, a Genomes to Life Project funded by the Office of Science, Basic Energy Research. The project was entitled "Methanogenic archaea and the global carbon cycle: a systems biology approach to the study of Methanosarcina species". The long-term goal of this multi-investigator project was the creation of integrated, multiscale models that accurately and quantitatively predict the role of Methanosarcina species in the global carbon cycle under dynamic environmental conditions. To achieve these goals we pursed four specific aims: (1) genome sequencing of numerous members of the Order Methanosarcinales, (2) identification of genomic sources of phenotypic variation through in silico comparative genomics, (3) elucidation of the transcriptional networks of two Methanosarcina species, and (4) development of comprehensive metabolic network models for characterized strains to address the question of how metabolic models scale with genetic distance.

  20. Green, red and infrared Er-related emission in implanted GaN:Er and GaN:Er,O samples

    SciTech Connect (OSTI)

    Monteiro, T.; Soares, J.; Correia, M. R.; Alves, E.

    2001-06-01

    Er-related luminescence near 1.54 {mu}m ({similar_to}805 meV) is observed under below band gap excitation at 4.2 K in GaN:Er and GaN:Er,O implanted samples. The spectrum of the recovered damage samples is a multiline structure. So far, these lines are the sharpest ones reported for GaN. Well-resolved green and red luminescences are observed in implanted samples. The dependence of luminescence on the excitation energy as well as the influence of different nominal fluence and annealing conditions is discussed. Combining the results obtained from photoluminescence and Rutherford backscattering spectrometry, different lattice sites for the optical active Er-related centers are identified. {copyright} 2001 American Institute of Physics.

  1. Crystal Structure and Thermodynamic Stability of Ba/Ti-Substituted Pollucites for Radioactive Cs/Ba Immobilization

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Xu, Hongwu; Chavez, Manuel E.; Mitchell, Jeremy N.; Garino, Terry J.; Schwarz, Haiqing L.; Rodriguez, Mark A.; Rademacher, David X.; Nenoff, Tina Maria

    2015-04-23

    An analogue of the mineral pollucite (CsAlSi2O6), CsTiSi2O6.5 has a potential host phase for radioactive Cs. However, as 137Cs and 135Cs transmute to 137Ba and 135Ba, respectively, through the beta decay, it is essential to study the structure and stability of this phase upon Cs → Ba substitution. In this work, two series of Ba/Ti-substituted samples, CsxBa(1-x)/2TiSi2O6.5 and CsxBa1-xTiSi2O7-0.5x, (x = 0.9 and 0.7), were synthesized by high-temperature crystallization from their respective precursors. Synchrotron X-ray diffraction and Rietveld analysis reveal that while CsxBa(1-x)/2TiSi2O6.5 samples are phase-pure, CsxBa1-xTiSi2O7-0.5x samples contain Cs3x/(2+x)Ba(1-x)/(2+x)TiSi2O6.5 pollucites (i.e., also two-Cs-to-one-Ba substitution) and a secondary phase, fresnoitemore » (Ba2TiSi2O8). Thus, the CsxBa1-xTiSi2O7-0.5x series is energetically less favorable than CsxBa(1-x)/2TiSi2O6.5. To study the stability systematics of CsxBa(1-x)/2TiSi2O6.5 pollucites, high-temperature calorimetric experiments were performed at 973 K with or without the lead borate solvent. Enthalpies of formation from the constituent oxides (and elements) have thus been derived. Our results show that with increasing Ba/(Cs + Ba) ratio, the thermodynamic stability of these phases decreases with respect to their component oxides. Hence, from the energetic viewpoint, continued Cs → Ba transmutation tends to destabilize the parent silicotitanate pollucite structure. However, the Ba-substituted pollucite co-forms with fresnoite (which incorporates the excess Ba), thereby providing viable ceramic waste forms for all the Ba decay products.« less

  2. Hadron Physics in BaBar

    SciTech Connect (OSTI)

    Lafferty, G.D.; /Manchester U.

    2005-08-29

    Some recent results in hadron physics from the BaBar experiment are discussed. In particular, the observation of two new charmed states, the D*{sub sJ}{sup +}(2317) and the D*{sub sJ}{sup +}(2457), is described, and results are presented on the first measurement of the rare decay mode of the B meson, B{sup 0} {pi}{sup 0}{pi}{sup 0}.

  3. Audit Report: ER-B-96-02 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Audit Report: ER-B-96-02 Audit Report: ER-B-96-02 June 11, 1996 Audit of Groundwater Remediation Plans at Savannah River PDF icon Audit Report: ER-B-96-02 More Documents &...

  4. Ammonia synthesis and ER-MCFC-technology - a profitable combination?

    SciTech Connect (OSTI)

    Dijkema, G.P.J.; Vervoort, J.; Daniels, R.J.E.; Luteijn, C.P.

    1996-12-31

    Similar to stand-alone ER-MCFC power systems industrial ammonia production facilities include hydrogen-rich synthesis-gas production. Therefore, integration of ER-MCFC stacks in a conventional industrial ammonia plant was investigated. By preliminary process design calculations three promising process structures were evaluated: (1) ER-MCFC is fed by the ammonia plant`s steam-reformer; anode off-gas to firing (2) similar to structure 1; in this case the anode off-gas is redirected to the ammonia process (3) ER-MCFC is fed by ammonia-synthesis purge gas The results indicate that for options 1 and 3 a return-on-investment for the ER-MCFC of around 8% is achievable at a stack cost of $250/kW and a revenue of 7c/kWh. Option 2 is not profitable, because of the associated reduction in ammonia production. The degree of hydrogen-utilization in the ER-MCFC to be selected for maximum profit varies with the process structure and indicates that there is scope for ER-MCFC stacks which operate at low hydrogen-utilization.

  5. SeeBA Energiesysteme GmbH | Open Energy Information

    Open Energy Info (EERE)

    search Name: SeeBA Energiesysteme GmbH Place: Stemwede, Germany Zip: 32351 Sector: Wind energy Product: Wind energy project developer, from planning through to implementation...

  6. Abnormal thermal conductivity in tetragonal tungsten bronze Ba...

    Office of Scientific and Technical Information (OSTI)

    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...

  7. ER2 Instrumentation and Measurements for CLASIC (Cloud Land Surface...

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

    ER2 Desired Measurements for CLASIC June 2007 SGP May 31, 2007 1 MEASUREMENT SOURCE DESIRED MEASUREMENTS AND PRODUCTS INSTRUMENT SYSTEMS Cloud Radar System (CRS), W-Band (95 GHz)...

  8. On the Verge of One Petabyte - the Story Behind the BaBar Database...

    Office of Scientific and Technical Information (OSTI)

    the Story Behind the BaBar Database System Citation Details In-Document Search Title: On the Verge of One Petabyte - the Story Behind the BaBar Database System The BaBar database ...

  9. Unitarity Triangle Angle Measurements at BaBar

    SciTech Connect (OSTI)

    Latham, Thomas E.; /SLAC

    2005-06-30

    We present recent results of measurements of the Unitarity Triangle angles alpha, beta and gamma made with the BaBar detector at the PEP-II asymmetric B factory. We present recent results of measurements of the Unitarity Triangle angles alpha, beta and gamma made with the BaBar detector at the PEP-II asymmetric B factory.

  10. Structure-Curie temperature relationships in BaTiO 3 -based ferroelect...

    Office of Scientific and Technical Information (OSTI)

    ferroelectric perovskites: Anomalous behavior of ( Ba , Cd ) TiO 3 from DFT, ... ferroelectric perovskites: Anomalous behavior of ( Ba , Cd ) TiO 3 from DFT, ...

  11. Innovative methodology for the synthesis of Ba-M hexaferrite BaFe{sub 12}O{sub 19} nanoparticles

    SciTech Connect (OSTI)

    Ahmed, M.A.; Helmy, N.; El-Dek, S.I.

    2013-09-01

    Graphical abstract: Transmission electron microscope images for the BaFe12O19. - Highlights: BaFe{sub 12}O{sub 19}nanoparticles were prepared in single-phase from organometallic precursors. BaFe{sub 12}O{sub 19} possesses small size 65 nm, H{sub C} = 3695 Oe and M{sub s} = 58 emu/g. This method of preparation could be extended in the synthesis of other metal oxide nanoparticles. - Abstract: In this piece of work, high quality and homogeneity, barium hexaferrite (BaM) BaFe{sub 12}O{sub 19} nanoparticles were prepared from organometallic precursors for the 1st time. This method is based on the formation of supramolecular crystal structure of Ba[Fe(H{sub 3}NCH{sub 2}CH{sub 2}NH{sub 3})]Cl{sub 7}8H{sub 2}O. The crystal structure, morphology and magnetic properties of BaFe{sub 12}O{sub 19} at two different annealing temperatures namely 1000 C and 1200 C were investigated using X-ray diffraction, transmission electron microscope TEM and vibrating sample magnetometry (VSM). The results show that monophasic nanoparticles of hexaferrites were obtained. Nanoparticles of crystallite size 4050 nm distinguished by narrow distribution and excellent homogeneity were obtained with superior magnetic properties which suggested single-domain particles of Ba-M hexaferrite.

  12. Coordination of Endoplasmic Reticulum (ER) Signaling During Maize Seed Development

    SciTech Connect (OSTI)

    Boston, Rebecca S.

    2010-11-20

    Seed storage reserves represent one of the most important sources of renewable fixed carbon and nitrogen found in nature. Seeds are well-adapted for diverting metabolic resources to synthesize storage proteins as well as enzymes and structural proteins needed for their transport and packaging into membrane bound storage protein bodies. Our underlying hypothesis is that the endoplasmic reticulum (ER) stress response provides the critical cellular control of metabolic flux required for optimal accumulation of storage reserves in seeds. This highly conserved response is a cellular mechanism to monitor the protein folding environment of the ER and restore homeostasis in the presence of unfolded or misfolded proteins. In seeds, deposition of storage proteins in protein bodies is a highly specialized process that takes place even in the presence of mutant proteins that no longer fold and package properly. The capacity of the ER to deposit these aberrant proteins in protein bodies during a period that extends several weeks provides an excellent model for deconvoluting the ER stress response of plants. We have focused in this project on the means by which the ER senses and responds to functional perturbations and the underlying intracellular communication that occurs among biosynthetic, trafficking and degradative pathways for proteins during seed development.

  13. Crystal Structure and Thermodynamic Stability of Ba/Ti-Substituted Pollucites for Radioactive Cs/Ba Immobilization

    SciTech Connect (OSTI)

    Xu, Hongwu; Chavez, Manuel E.; Mitchell, Jeremy N.; Garino, Terry J.; Schwarz, Haiqing L.; Rodriguez, Mark A.; Rademacher, David X.; Nenoff, Tina Maria

    2015-04-23

    An analogue of the mineral pollucite (CsAlSi2O6), CsTiSi2O6.5 has a potential host phase for radioactive Cs. However, as 137Cs and 135Cs transmute to 137Ba and 135Ba, respectively, through the beta decay, it is essential to study the structure and stability of this phase upon Cs → Ba substitution. In this work, two series of Ba/Ti-substituted samples, CsxBa(1-x)/2TiSi2O6.5 and CsxBa1-xTiSi2O7-0.5x, (x = 0.9 and 0.7), were synthesized by high-temperature crystallization from their respective precursors. Synchrotron X-ray diffraction and Rietveld analysis reveal that while CsxBa(1-x)/2TiSi2O6.5 samples are phase-pure, CsxBa1-xTiSi2O7-0.5x samples contain Cs3x/(2+x)Ba(1-x)/(2+x)TiSi2O6.5 pollucites (i.e., also two-Cs-to-one-Ba substitution) and a secondary phase, fresnoite (Ba2TiSi2O8). Thus, the CsxBa1-xTiSi2O7-0.5x series is energetically less favorable than CsxBa(1-x)/2TiSi2O6.5. To study the stability systematics of CsxBa(1-x)/2TiSi2O6.5 pollucites, high-temperature calorimetric experiments were performed at 973 K with or without the lead borate solvent. Enthalpies of formation from the constituent oxides (and elements) have thus been derived. Our results show that with increasing Ba/(Cs + Ba) ratio, the thermodynamic stability of these phases decreases with respect to their component oxides. Hence, from the energetic viewpoint, continued Cs → Ba transmutation tends to destabilize the parent silicotitanate pollucite structure. However, the Ba-substituted pollucite co-forms with fresnoite (which incorporates the excess Ba

  14. DOE - Office of Legacy Management -- GrnRiv

    Office of Legacy Management (LM)

    All documents are Adobe Acrobat files. pdficon Key Documents Fact Sheet 2015 Annual Site Inspection and Monitoring Report for Uranium Mill Tailings Radiation Control Act Title I ...

  15. DOE - Office of Legacy Management -- GrnRiv

    Office of Legacy Management (LM)

    Utah Green River, Utah, Disposal Site UMTRCA Title I site grn_map The Green River disposal site, a Uranium Mill Tailings Radiation Control Act (UMTRCA) Title I disposal site, is licensed to DOE for long-term custody and managed by the Office of Legacy Management. The site transferred to the Office of Legacy Management in 2003 and requires routine inspection and maintenance, records-related activities, and stakeholder support. For more information about the Green River site, view the fact sheet.

  16. ARM - Field Campaign - AERI-ER Intercomparison IOP

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

    govCampaignsAERI-ER Intercomparison IOP ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : AERI-ER Intercomparison IOP 2004.01.12 - 2006.06.29 Lead Scientist : David Turner Data Availability Data were collected and submitted to the ARM Archive for IOPs. For data sets, see below. Summary There were three, potentially four, phases to this experiment. The length of time required for each phase was the time

  17. Ba2TeO: A new layered oxytelluride

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Besara, T.; Ramirez, D.; Sun, J.; Whalen, J. B.; Tokumoto, T. D.; McGill, S. A.; Singh, D. J.; Siegrist, T.

    2015-02-01

    For single crystals of the new semiconducting oxytelluride phase, Ba2TeO, we synthesized from barium oxide powder and elemental tellurium in a molten barium metal flux. Ba2TeO crystallizes in tetragonal symmetry with space group P4/nmm (#129), a=5.0337(1) Å, c=9.9437(4) Å, Z=2. The crystals were characterized by single crystal x-ray diffraction, heat capacity and optical measurements. Moreover, the optical measurements along with electronic band structure calculations indicate semiconductor behavior with a band gap of 2.93 eV. Resistivity measurements show that Ba2TeO is highly insulating.

  18. Pahute Mesa Well Development and Testing Analyses for Wells ER-20-7, ER-20-8 #2, and ER-EC-11, Revision 1

    SciTech Connect (OSTI)

    Greg Ruskauff

    2011-12-01

    This report analyzes the following data collected from ER-20-7, ER-20-8 No.2, and ER-EC-11 during WDT operations: (1) Chemical indicators of well development (Section 2.0); (2) Static hydraulic head (Section 3.0); (3) Radiochemistry and geochemistry (Section 4.0); (4) Drawdown observed at locations distal to the pumping well (Section 5.0); and (5) Drilling water production, flow logs, and temperature logs (Section 6.0). The new data are further considered with respect to existing data as to how they enhance or change interpretations of groundwater flow and transport, and an interim small-scale conceptual model is also developed and compared to Phase I concepts. The purpose of well development is to remove drilling fluids and drilling-associated fines from the formation adjacent to a well so samples reflecting ambient groundwater water quality can be collected, and to restore hydraulic properties near the well bore. Drilling fluids can contaminate environmental samples from the well, resulting in nonrepresentative measurements. Both drilling fluids and preexisting fines in the formation adjacent to the well can impede the flow of water from the formation to the well, creating artifacts in hydraulic response data measured in the well.

  19. Symmetry-Breaking Orbital Anisotropy Observed for Detwinned Ba...

    Office of Scientific and Technical Information (OSTI)

    Symmetry-Breaking Orbital Anisotropy Observed for Detwinned Ba(Fe (1-X) Co (X) ) (2) As (2) Above the Spin Density Wave Transition Citation Details In-Document Search Title: ...

  20. The analysis of Ytrium doped BaZrO3

    Office of Scientific and Technical Information (OSTI)

    Enhanced Power Stability for Proton Conducting Solid Oxides Fuel Cells Report Title: Computational modeling, synthesis, and characterization of BaZr 1-x Y x O 3- solid state ...

  1. Transition probabilities in the X(5) candidate {sup 122}Ba

    SciTech Connect (OSTI)

    Bizzeti, P. G.; Giannatiempo, A.; Melon, B.; Perego, A.; Sona, P.; Bizzeti-Sona, A. M.; Tonev, D.; Ur, C. A.; Bazzacco, D.; Farnea, E.; Marginean, R.; Menegazzo, R.; Rossi Alvarez, C.; Dewald, A.; Fransen, C.; Michelagnoli, C.; Lenzi, S.; Lunardi, S.; Mengoni, D.; Nespolo, M.

    2010-11-15

    To investigate the possible X(5) character of {sup 122}Ba, suggested by the ground-state band energy pattern, the lifetimes of the lowest yrast states of {sup 122}Ba have been measured, via the recoil distance Doppler-shift method. The relevant levels have been populated by using the {sup 108}Cd({sup 16}O,2n){sup 122}Ba and the {sup 112}Sn({sup 13}C,3n){sup 122}Ba reactions. The B(E2) values deduced in the present work are compared to the predictions of the X(5) model and to calculations performed in the framework of the IBA-1 and IBA-2 models.

  2. Completion report for Well Cluster ER-20-6

    SciTech Connect (OSTI)

    1998-02-01

    The Well Cluster ER-20-6 drilling and completion project was conducted during February, March, and April of 1996 in support of the Nevada Environmental Restoration Project at the Nevada Test Site (NTS), Nye County, Nevada. This project is part of the DOE`s Underground Test Area (UGTA) subproject at the NTS. The primary UGTA tasks include collecting geological, geophysical, and hydrological data from new and existing wells to define groundwater quality as well as pathways and rates of groundwater migration at the NTS. A program of drilling wells near the sites of selected underground nuclear tests (near-field drilling) was implemented as part of the UGTA subproject to obtain site-specific data on the nature and extent of migration of radionuclides produced by an underground nuclear explosion. The ER-20-6 near-field drilling project was originally planned to be very similar to that recently conducted at Well Cluster ER-20-5, which was designed to obtain data on the existing hydrologic regime near the site of an underground nuclear explosion (IT, 1995; IT, 1996a). However, after further consideration of the goals of the near-field drilling program and the characteristics of the BULLION site, the TWG recommended that the ER-20-6 project be redesigned to accommodate a forced-gradient experiment. This proposed experiment is expected to yield more realistic estimates of transport parameters than can be deduced from sampling and testing natural groundwater flow systems.

  3. Leptonic B Decays at BaBar

    SciTech Connect (OSTI)

    Monorchio, Diego; /INFN, Naples /Naples U.

    2011-09-13

    The authors will present the most recent results on leptonic B decays B{sup {+-}(0)} {yields} K*{sup {+-}(0)} {nu}{bar {nu}} and B{sup {+-}} {yields} {mu}{sup {+-}}{nu}, based on the data collected by the BaBar detector at PEP-II, an asymmetric e{sup +}e{sup -} collider at the center of mass energy of the {Upsilon}(4S) resonance. Rare B decays have always been a standard probe for New Physics (NP) searches. The very low Standard Model (SM) rate of these decays often make them unaccessible with the present experimental datasets, unless NP effects enhance the rate up to the current experimental sensitivity. Moreover, as NP effects can modify the decay kinematic, particular attention must be payed in order to perform a model independent analysis. A B-Factory provides an unique environment where to investigate these processes. The high number of B{bar B} pairs produced by a B-Factory often allows to approach the needed experimental sensitivity. Moreover, the clean environment and the closed kinematic of the initial state enable to obtaining a very pure sample where to look for these decays.

  4. Leptonic B Decays at BaBar

    SciTech Connect (OSTI)

    Baracchini, Elisabetta; /Rome U. /INFN, Rome

    2011-11-10

    We will present the most recent results on leptonic B decays B{sup {+-}(0)} {yields} K*{sup {+-}(0)}{nu}{bar {nu}} and B{sup {+-}} {yields} {mu}{sup {+-}}{nu}, based on the data collected by the BaBar detector at PEP-II, an asymmetric e{sup +}e{sup -} collider at the center of mass energy of the {Upsilon}(4S) resonance. Rare B decays have always been a standard probe for New Physics (NP) searches. The very low Standard Model (SM) rate of these decays often make them unaccessible with the present experimental datasets, unless NP effects enhance the rate up to the current experimental sensitivity. Moreover, as NP effects can modify the decay kinematic, particular attention must be paid in order to perform a model independent analysis. A B-Factory provides an unique environment to investigate these processes. The high number of B{bar B} pairs produced by a B-Factory often allows to approach the needed experimental sensitivity. Moreover, the clean environment and the closed kinematic of the initial state enable to obtaining a very pure sample where to look for these decays.

  5. Inner Mongolia Bayannao er Fuhui Wind Power Co Ltd | Open Energy...

    Open Energy Info (EERE)

    Bayannao er Fuhui Wind Power Co Ltd Jump to: navigation, search Name: Inner Mongolia Bayannao'er Fuhui Wind Power Co Ltd Place: Inner Mongolia Autonomous Region, China Sector: Wind...

  6. USACE ER 200-2-2 Procedures for Implementing NEPA | Open Energy...

    Open Energy Info (EERE)

    ER 200-2-2 Procedures for Implementing NEPA Jump to: navigation, search OpenEI Reference LibraryAdd to library PermittingRegulatory Guidance - GuideHandbook: USACE ER 200-2-2...

  7. Audit Report: ER-FS-99-03 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    3 Audit Report: ER-FS-99-03 May 25, 1999 Matters Identified at the Savannah River ... Audit Report: ER-FS-99-03 (19.56 KB) More Documents & Publications Audit Report: ...

  8. Audit Report: ER-B-97-03 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    3 Audit Report: ER-B-97-03 June 5, 1997 Audit of Proposal to Acquire Land at the Fernald Environmental Management Project PDF icon Audit Report: ER-B-97-03 More Documents & ...

  9. Magnetic properties of Er1-xDyxAl2 (0 ≤ x ≤ 1) compounds...

    Office of Scientific and Technical Information (OSTI)

    Er1-xDyxAl2 (0 x 1) compounds in low applied fields Citation Details In-Document Search Title: Magnetic properties of Er1-xDyxAl2 (0 x 1) compounds in low applied ...

  10. Bosch Solar Energy AG former ErSol Solar Energy AG | Open Energy...

    Open Energy Info (EERE)

    AG former ErSol Solar Energy AG Jump to: navigation, search Name: Bosch Solar Energy AG (former ErSol Solar Energy AG) Place: Erfurt, Germany Zip: D-99099 Product: Germany-based...

  11. Final Report: DOE award: ER64516-1031199-0013966 2007-2011 Genomic...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Final Report: DOE award: ER64516-1031199-0013966 2007-2011 Genomic ... Title: Final Report: DOE award: ER64516-1031199-0013966 2007-2011 Genomic Structure, ...

  12. FINAL REPORT DE-FG02-07ER15894 (Technical Report) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Technical Report: FINAL REPORT DE-FG02-07ER15894 Citation Details In-Document Search Title: FINAL REPORT DE-FG02-07ER15894 One of the greatest technological hurdles to deployment ...

  13. Audit Report: ER-B-96-01 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    1 Audit Report: ER-B-96-01 April 23, 1996 Force Restructuring at the Fernald Environmental Management Project Audit Report: ER-B-96-01 (72.18 KB) More Documents & Publications Audit Report: ER-B-98-06 Semiannual Report to Congress: April 1, 1996 - September 30, 1996 Draft Policy and Planning Guidance for Community Transition Activities

  14. Completion report for well ER-30-1

    SciTech Connect (OSTI)

    1995-12-01

    Well ER-30-1 was drilled for the U.S. Department of Energy (DOE), Nevada Operations Office, in support of the Nevada Environmental Restoration Project at the Nevada Test Site (NTS). IT Corporation (IT) was the principal environmental contractor for the project. The roles and responsibilities of IT and other contractors involved in the project are described in the Raytheon Services Nevada (RSN) Drilling and Completion Programs and the Underground Test Area Operable Unit Project Management Plan. The Well ER-30-1 investigation is part of the DOE`s Underground Test Area (UGTA) Project at the NTS, the goals of which include collecting geological, geophysical, hydrological, and water-chemistry data from new and existing wells to define groundwater migration pathways, rates of migration, and groundwater quality at the NTS. The well will become part of the UGTA monitoring well network.

  15. Grant No. DE=FG03=86ER113469

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

    Annual Report, 1993 Grant No. DE=FG03=86ER113469 "Research in Chemical Kinetics" Principal Ihvestigator, F. S. Rowland This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or use- fulness of any information, apparatus, product,

  16. 02-10ER85986 | netl.doe.gov

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

    Swellable Organosilica Materials to Clean Produced Water Last Reviewed 6/3/2016 02-10ER85986 Goal The project is targeted at a more general solution of improving refinery wastewater treatment. Successful completion of the revised Phase IIB goals will allow ABS Materials to provide a more applicable technology solution by capturing a broad range of organic compounds from a variety of refinery process waste streams. Some of these organics are valuable feedstock, so the capture and return function

  17. ER85357_Phase2_Eltron | netl.doe.gov

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

    Unconventional High Temperature Nanofiltration for Produced Water Treatment Last Reviewed 6/25/2013 DE-10ER85357 Goal The project goal is to further develop a proprietary, high-temperature nanofiltration (NF) technology (DurafluxTM) to remove salt and other dissolved solids from produced water originating from domestic oil and gas production. Treated water can be re-used in the extraction process without cooling/re-heating costs or can be recycled as an acceptable supply of source water. Project

  18. Final Report DE-FG02-07ER64416

    SciTech Connect (OSTI)

    Seymour, Joseph D.

    2014-02-01

    The document provides the Final Report for DE-FG02-07ER64416 on the use of magnetic resonance (MR) methods to quantify transport in porous media impacted by biological and chemical processes. Products resulting from the research in the form of peer reviewed publications and conference presentations are presented. The research correlated numerical simulations and MR measurements to test simulation methodology. Biofilm and uranium detection by MR was demonstrated.

  19. Tunable, diode side-pumped Er: YAG laser

    DOE Patents [OSTI]

    Hamilton, Charles E.; Furu, Laurence H.

    1997-01-01

    A discrete-element Er:YAG laser, side pumped by a 220 Watt peak-power InGaAs diode array, generates >500 mWatts at 2.94 .mu.m, and is tunable over a 6 nm range near about 2.936 .mu.m. The oscillator is a plano-concave resonator consisting of a concave high reflector, a flat output coupler, a Er:YAG crystal and a YAG intracavity etalon, which serves as the tuning element. The cavity length is variable from 3 cm to 4 cm. The oscillator uses total internal reflection in the Er:YAG crystal to allow efficient coupling of the diode emission into the resonating modes of the oscillator. With the tuning element removed, the oscillator produces up to 1.3 Watts of average power at 2.94 .mu.m. The duty factor of the laser is 6.5% and the repetition rate is variable up to 1 kHz. This laser is useful for tuning to an atmospheric transmission window at 2.935 .mu.m (air wavelength). The laser is also useful as a spectroscopic tool because it can access several infrared water vapor transitions, as well as transitions in organic compounds. Other uses include medical applications (e.g., for tissue ablation and uses with fiber optic laser scalpels) and as part of industrial effluent monitoring systems.

  20. Tunable, diode side-pumped Er:YAG laser

    DOE Patents [OSTI]

    Hamilton, C.E.; Furu, L.H.

    1997-04-22

    A discrete-element Er:YAG laser, side pumped by a 220 Watt peak-power InGaAs diode array, generates >500 mWatts at 2.94 {micro}m, and is tunable over a 6 nm range near about 2.936 {micro}m. The oscillator is a plano-concave resonator consisting of a concave high reflector, a flat output coupler, a Er:YAG crystal and a YAG intracavity etalon, which serves as the tuning element. The cavity length is variable from 3 cm to 4 cm. The oscillator uses total internal reflection in the Er:YAG crystal to allow efficient coupling of the diode emission into the resonating modes of the oscillator. With the tuning element removed, the oscillator produces up to 1.3 Watts of average power at 2.94 {micro}m. The duty factor of the laser is 6.5% and the repetition rate is variable up to 1 kHz. This laser is useful for tuning to an atmospheric transmission window at 2.935 {micro}m (air wavelength). The laser is also useful as a spectroscopic tool because it can access several infrared water vapor transitions, as well as transitions in organic compounds. Other uses include medical applications (e.g., for tissue ablation and uses with fiber optic laser scalpels) and as part of industrial effluent monitoring systems. 4 figs.

  1. Completion Report for Well Cluster ER-5-4

    SciTech Connect (OSTI)

    U.S. Department of Energy, National Nuclear Security Administration, Nevada Site Office; Bechtel Nevada

    2005-02-01

    Well Cluster ER-5-4 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office, in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. The cluster consists of two wells, positioned about 30 meters apart on the same drill pad, constructed as part of a hydrogeologic investigation program for Frenchman Flat at the Nevada Test Site. Detailed lithologic descriptions with preliminary stratigraphic assignments for the well cluster are included in this report. These are based on composite drill cuttings collected every 3 meters, and 156 sidewall samples taken at various depths below 192 meters in both boreholes, supplemented by geophysical log data. Detailed petrographic, chemical, and mineralogical studies of rock samples were conducted on 122 samples. Well ER-5-4 penetrated approximately 1,120 meters of Quaternary and Tertiary alluvium before reaching total depth in Tertiary volcanic rocks at 1,137.5 meters. The deeper Well ER-5-4 No.2 penetrated 1,120.4 meters of alluvial sediments, and was terminated within Tertiary volcanic rocks at a depth of 2,133.6 meters, indicating that Paleozoic rocks are deeper than expected at this site.

  2. Completion Report for Well Cluster ER-6-1

    SciTech Connect (OSTI)

    Bechtel Nevada

    2004-10-01

    Well Cluster ER-6-1 was constructed for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of the Nevada Environmental Restoration Division at the Nevada Test Site, Nye County, Nevada. This work was initiated as part of the Groundwater Characterization Project, now known as the Underground Test Area Project. The well cluster is located in southeastern Yucca Flat. Detailed lithologic descriptions with stratigraphic assignments for Well Cluster ER-6-1 are included in this report. These are based on composite drill cuttings collected every 3 meters and conventional core samples taken below 639 meters, supplemented by geophysical log data. Detailed petrographic, chemical, and mineralogical studies of rock samples were conducted on 11 samples to resolve complex interrelationships between several of the Tertiary tuff units. Additionally, paleontological analyses by the U.S. Geological Survey confirmed the stratigraphic assignments below 539 meters within the Paleozoic sedimentary section. All three wells in the Well ER-6-1 cluster were drilled within the Quaternary and Tertiary alluvium section, the Tertiary volcanic section, and into the Paleozoic sedimentary section.

  3. X-ray and neutron diffraction of Er-hydride films.

    SciTech Connect (OSTI)

    Rodriguez, Mark Andrew

    2004-10-01

    The outline of this report is: (1) structures of hexagonal Er meal, ErH{sub 2} fluorite, and molybdenum; (2) texture issues and processing effects; (3) idea of pole figure integration; and (4) promising neutron diffraction work. Summary of this report are: (1) ErD{sub 2} and ErT{sub 2} film microstructures are strongly effected by processing conditions; (2) both x-ray and neutron diffraction are being pursued to help diagnose structure/property issues regarding ErT{sub 2} films and these correlations to He retention/release; (3) texture issues are great challenges for determination of site occupancy; and (4) work on pole-figure-integration looks to have promise addressing texture issues in ErD{sub 2} and ErT{sub 2} films.

  4. Processing of R-Ba-Cu-O superconductors

    SciTech Connect (OSTI)

    Wu, H.

    1998-02-23

    Precipitation processes were developed to introduce second phases as flux pinning centers in Gd-Ba-Cu-O and Nd-Ba-Cu-O superconductors. In Gd-Ba-Cu-O, precipitation is caused by the decrease of the upper solubility limit of Gd{sub 1+x}Ba{sub 2{minus}x}Cu{sub 3}O{sub 7} solid solution (Gd123ss) in low oxygen partial pressure. Processing of supersaturated Gd{sub 1.2}Ba{sub 1.8}Cu{sub 3}O{sub 7} in low oxygen partial pressure can produce dispersed second phases. Gd211 is formed as a separate phase while extensive Gd124 type stacking fault is formed instead of a separate CuO phase. As a result of the precipitation reaction, the transition temperature and critical current density are increased. In Nd-Ba-Cu-O, precipitation is caused by the decrease of the lower solubility limit of Nd{sub 1+x}Ba{sub 2{minus}x}Cu{sub 3}O{sub 7} solid solution (Nd123ss) in oxygen. DTA results reveal the relative stability of Nd123ss in different oxygen partial pressures. In 1 bar oxygen partial pressure, Nd123ss with x = 0.1 is the most stable phase. In lower oxygen partial pressures, the most stable composition shifts towards the stoichiometric composition. The relative stability changes faster with decreasing oxygen partial pressure. Therefore, processing in oxygen and air tends to produce broad superconducting transitions but sharp transitions can be achieved in 0.01 bar and 0.001 bar oxygen partial pressures. While the lower solubility limits in 0.01 bar and 0.001 bar oxygen partial pressures remain at x = 0.00, the solubility limits in oxygen and air show a narrowing with decreasing temperature. Because of the narrowing of the solubility range in oxygen, oxygen annealing of Nd123 initially processed in low oxygen partial pressures will result in precipitation of second phases. The equilibrium second phase is BaCuO{sub 2} for temperature above 608 C, and at lower temperatures the equilibrium second phases are Ba{sub 2}CuO{sub 3.3} and Ba{sub 2}Cu{sub 3}O{sub 5+y}. However, annealing at

  5. COMPLETION REPORT FOR WELL CLUSTER ER-5-3

    SciTech Connect (OSTI)

    BECHTEL NEVADA

    2005-12-01

    Well Cluster ER-5-3 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. This cluster of 3 wells was drilled in 2000 and 2001 as part of a hydrogeologic investigation program in Frenchman Flat. The first borehole in the cluster, Well ER-5-3, was drilled in February and March 2000. A 47.0-centimeter surface hole was drilled and cased off to the depth of 374.8 meters. The hole diameter was decreased to 31.1 centimeters for drilling to a total depth of 794.3 meters within welded ash-flow tuff. A piezometer string with 1 slotted interval was installed in the annulus of the surface casing, open to the saturated alluvium. A completion string with 2 slotted intervals was installed in the main hole, open to saturated alluvium and to the welded tuff aquifer. A second piezometer string with 1 slotted interval open to the welded-tuff aquifer was installed outside the completion string. Well ER-5-3 No.2 was drilled about 30 meters west of the first borehole in March 2000, and was recompleted in March 2001. A 66.0-centimeter hole was drilled and cased off to the depth of 613.8 meters. The hole diameter was decreased to 44.5 centimeters and the borehole was drilled and cased off to the depth of 849.0 meters. The hole diameter was decreased once more to 31.1 centimeters for drilling to a total depth of 1,732.2 meters in dolomite. A completion string open to the dolomite (lower carbonate aquifer) was installed. Well ER-5-3 No.3 was drilled approximately 30 meters north of the first 2 boreholes in February 2001. A 66.0-centimeter hole was drilled and cased off to the depth of 36.6 meters, then the main 25.1-centimeter-diameter hole was drilled to a total depth of 548.6 meters in alluvium. A slotted stainless-steel tubing string was installed in the saturated alluvium. A preliminary composite, static water level was measured at

  6. Observation of excited states in /sup 128/Ba

    SciTech Connect (OSTI)

    Zhao Zhi-zheng; Guo Ying-xiang; Pan Zong-you; Xiao Jian-min; Lei Xiang-guo; Liu Hong-ye; Sun Xi-jun

    1987-01-01

    Excited states in /sup 128/Ba have been investigated via the /sup 120/Sn (/sup 12/C, 4n..gamma..) /sup 128/Ba reaction by means of in-beam gamma spectroscopy. A 12/sup +/ state other than the previously reported one is observed according to the properties of the 935.0 keV ..gamma..-ray. It does not belong to the ground-state band. Two new interband transitions, 224.8 keV and 632.7 keV, are observed and assigned to sidefeeding between the negative-parity band and ground-state band.

  7. Study of the Decays of Charm Mesons With the BaBar Experiment...

    Office of Scientific and Technical Information (OSTI)

    Study of the Decays of Charm Mesons With the BaBar Experiment Citation Details In-Document Search Title: Study of the Decays of Charm Mesons With the BaBar Experiment You are ...

  8. Electric control of magnetism at the Fe/BaTiO3 interface (Journal...

    Office of Scientific and Technical Information (OSTI)

    Electric control of magnetism at the FeBaTiO3 interface Citation Details In-Document Search Title: Electric control of magnetism at the FeBaTiO3 interface Interfacial ...

  9. Optimizing Parallel Access to the BaBar Database System Using...

    Office of Scientific and Technical Information (OSTI)

    Optimizing Parallel Access to the BaBar Database System Using CORBA Servers Citation Details In-Document Search Title: Optimizing Parallel Access to the BaBar Database System Using ...

  10. Bottomonium Spectroscopy at BaBar and Belle (Conference) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    Bottomonium Spectroscopy at BaBar and Belle Citation Details In-Document Search Title: Bottomonium Spectroscopy at BaBar and Belle You are accessing a document from the ...

  11. Production of BaBar Skimmed Analysis Datasets Using the Grid...

    Office of Scientific and Technical Information (OSTI)

    Production of BaBar Skimmed Analysis Datasets Using the Grid Citation Details In-Document Search Title: Production of BaBar Skimmed Analysis Datasets Using the Grid You are ...

  12. Electric control of magnetism at the Fe/BaTiO3 interface (Journal...

    Office of Scientific and Technical Information (OSTI)

    Electric control of magnetism at the FeBaTiO3 interface Citation Details In-Document Search Title: Electric control of magnetism at the FeBaTiO3 interface You are accessing a ...

  13. Searches for Light New Physics at BaBar (Conference) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Search Results Conference: Searches for Light New Physics at BaBar Citation Details In-Document Search Title: Searches for Light New Physics at BaBar Authors: ...

  14. Grant No. DE-FG03-86ER-13469

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

    Report, 1994 Grant No. DE-FG03-86ER-13469 "Research in Chemical Kinetics'' Principal Investigator, F. S. Rowland DISCLAIMER T h i s report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or use- fulness of any information, apparatus, product,

  15. Structural phase transitions in BaPrO{sub 3}

    SciTech Connect (OSTI)

    Saines, Paul J.; Kennedy, Brendan J. Smith, Ronald I.

    2009-04-02

    The crystal structures adopted by BaPrO{sub 3} at and above ambient temperature have been examined using a combination of synchrotron X-ray and neutron diffraction. BaPrO{sub 3} has been established to undergo a series of phase transitions from Pbnmorthorhombic{yields}Ibmmorthorhombic{yields}R3-bar crhombohedral{yields}Pm3-barm cubic. BaPrO{sub 3} is the second A{sup 2+}B{sup 4+}O{sub 3} perovskite found to adopt rhombohedral symmetry in preference to the I4/mcm tetragonal structure. Analysis of the octahedral tilting through the rhombohedral to cubic phase transition indicates that this transformation is continuous and tricritical in nature. The tricritical behaviour of this transition is likely to be a result of the competition between tetragonal and rhombohedral structures to be the preferred phase, with the rhombohedral symmetry adopted by BaPrO{sub 3} being stabilised by the unusually large B-site cation.

  16. 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.

  17. Audit Report: ER-B-95-06 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    6 Audit Report: ER-B-95-06 August 3, 1995 Audit of Work Force Restructuring at the Oak Ridge Operations Office Audit Report: ER-B-95-06 (103.77 KB) More Documents & Publications Audit Report: ER-B-96-01 Draft Policy and Planning Guidance for Community Transition Activities Authorize_Changes_Contractor_Work_Force_Restructuring_Policy.pdf

  18. ER Consolidated Qtrly Rpt_July-September 2015_January 2016

    SciTech Connect (OSTI)

    Cochran, John R.

    2016-01-01

    This Environmental Restoration Operations (ER) Consolidated Quarterly Report (ER Quarterly Report) provides the status of ongoing corrective action activities being implemented by Sandia National Laboratories, New Mexico (SNL/NM) for the July, August, and September 2015 quarterly reporting period. The Solid Waste Management Units (SWMUs) and Areas of Concern (AOCs) identified for corrective action at SNL/NM are listed in Table I-1. The work completed during this quarter is reported below in Sections I.2.1 and I.2.2. Section I.2.1 summarizes the quarterly activities at sites undergoing corrective action field activities (SWMUs 8 and 58, 68, 149, 154, and 502, and three groundwater AOCs). Section I.2.2 summarizes quarterly activities at sites where the New Mexico Environment Department (NMED) has issued a certificate of completion and the site is in the corrective action complete (CAC) regulatory process. Currently, the Mixed Waste Landfill (MWL, SWMU 76) is the only site in the CAC regulatory process. Corrective action activities have been deferred at the Long Sled Track (SWMU 83), the Gun Facilities (SWMU 84), and the Short Sled Track (SWMU 240) because these are active mission facilities.

  19. Completion Report for Well ER-8-1

    SciTech Connect (OSTI)

    Bechtel Nevada

    2004-11-01

    Well ER-8-1 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. This well was drilled in October and November of 2002 as part of a Hydrogeologic investigation program for the Yucca Flat/Climax Mine Corrective Action Unit in the northeastern portion of the Nevada Test Site. Well ER-8-1 is located at the north end of Yucca Flat approximately 580 meters south-southeast of the surface exposure of the Climax granitic intrusive. Detailed lithologic descriptions with stratigraphic assignments are included in this report. These are based on composite drill cuttings samples collected every 3 meters, and 21 sidewall samples taken at various depths between 351.1 and 573.0 meters, supplemented by incomplete geophysical log data. Detailed petrographic, geochemical, and mineralogical studies of rock samples were conducted on 22 samples of drill cuttings. Drilling began in tuffaceous alluvium, and the borehole penetrated Tertiary age bedded tuffs of the Volcanics of Oak Spring Butte and carbonate sediments of Paleozoic age, which were encountered at a depth of 334 meters. The borehole unexpectedly penetrated granite at the depth of 538.9 meters in which drilling was stopped. Contact metamorphic rocks and intrusive dikes associated with the Cretaceous-age granitic intrusive and at least one significant fault zone were encountered.

  20. Completion Report for Well ER-2-1

    SciTech Connect (OSTI)

    Bechtel Nevada

    2004-10-01

    Well ER-2-1 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office (formerly Nevada Operations Office), in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. This well was drilled in February and March of 2003, as part of a hydrogeologic investigation program for the Yucca Flat/Climax Mine Corrective Action Unit in the northeastern portion of the Nevada Test Site. Well ER-2-1 was drilled as part of the Yucca Flat Corrective Action Unit Phase I drilling initiative. The well is located in north central Yucca Flat within Area 2 of the Nevada Test Site, and provided information regarding the radiological and physical environment near underground nuclear tests conducted in a saturated volcanic aquifer setting. Detailed lithologic descriptions with stratigraphic assignments are included in this report. These are based on composite drill cuttings collected every 3 meters and 83 sidewall samples taken at various depths between 113.7 and 754.4 meters, supplemented by geophysical log data. Detailed petrographic, chemical, and mineralogical studies of rock samples were conducted on 27 samples of drill cuttings. The well was collared in tuffaceous alluvium, and penetrated Tertiary-age tuffs of the Timber Mountain and Paintbrush Groups, Calico Hills and Wahmonie Formations, Crater Flat Group, Grouse Canyon Formation, before reaching total depth in the Tunnel Bed Formation.

  1. Environmental Release Summary (ERS) database CY 1995 releases and supporting data

    SciTech Connect (OSTI)

    Gleckler, B.P., Westinghouse Hanford

    1996-08-05

    This document is a hard copy of the CY 1995 airborne and liquid effluent data contained in the Environmental Release Summary (ERS) computer database.

  2. Final Technical Report for DOE Grant, number DE-FG02-05ER15701...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Final Technical Report for DOE Grant, number DE-FG02-05ER15701; Probing Surface Chemistry Under Catalytic Conditions: Olefin Hydrogenation,Cyclization and ...

  3. Hydrothermal synthesis and magnetic properties of ErCrO{sub 4} nanoparticles

    SciTech Connect (OSTI)

    Sundarayya, Y. Kumar, K. Ashwini Sondge, Rajesh Srinath, S. Kaul, S. N.

    2014-04-24

    Homogeneous single phase ErCrO{sub 4} nanoparticles have been synthesized by a modified sol-gel followed by hydrothermal method. X-ray diffraction reveals that the compound crystallizes into tetragonal structure with space group I41/amd. The average crystallite size was estimated to be 21(1) nm. Morphological analysis of the sample confirms uniform particles of size 20 nm. DC magnetic measurements show that ErCrO{sub 4} undergoes a paramagnetic-antiferromagnetic transition at 16 K, due to the superexchange Er-O-Cr-O-Er antiferromagnetic interactions.

  4. PO*WW*ER mobile treatment unit process hazards analysis

    SciTech Connect (OSTI)

    Richardson, R.B.

    1996-06-01

    The objective of this report is to demonstrate that a thorough assessment of the risks associated with the operation of the Rust Geotech patented PO*WW*ER mobile treatment unit (MTU) has been performed and documented. The MTU was developed to treat aqueous mixed wastes at the US Department of Energy (DOE) Albuquerque Operations Office sites. The MTU uses evaporation to separate organics and water from radionuclides and solids, and catalytic oxidation to convert the hazardous into byproducts. This process hazards analysis evaluated a number of accident scenarios not directly related to the operation of the MTU, such as natural phenomena damage and mishandling of chemical containers. Worst case accident scenarios were further evaluated to determine the risk potential to the MTU and to workers, the public, and the environment. The overall risk to any group from operation of the MTU was determined to be very low; the MTU is classified as a Radiological Facility with low hazards.

  5. Completion Report for Well ER-18-2

    SciTech Connect (OSTI)

    Bechtel Nevada

    2003-09-01

    Well ER-18-2 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. This well, located on Buckboard Mesa in the western part of the Nevada Test Site, was drilled in the spring of 1999 as part of the U.S. Department of Energy's hydrogeologic investigation well program in the Western Pahute Mesa - Oasis Valley region just west of the Test Site. A 44.5-centimeter surface hole was drilled and cased off to the depth 408.1 meters below the surface. The hole diameter was then decreased to 31.1 centimeters for drilling to a total depth of 762.0 meters. A preliminary composite, static, water level was measured at the depth of approximately 369.7 meters approximately two months after the completion string was installed. One completion string with three isolated, slotted intervals was installed in the well. Detailed lithologic descriptions with preliminary stratigraphic assignments are included in the report. These are based on composite drill cuttings collected every 3 meters and 15 sidewall samples taken at various depths below 420 meters, supplemented by geophysical log data and results of detailed chemical and mineralogical studies of rock samples. The upper part of the well penetrated Tertiary-age basalt, underlain by tuffaceous moat-filling sediments interbedded with ash-flow tuff units of the Thirsty Canyon Group and the Beatty Wash Formation. The lower half of the drill hole penetrated ash-flow tuff of the mafic-rich Ammonia Tanks Tuff. The geologic interpretation of data from Well ER-18-2 indicates that this site is located inside the structural margin of the Ammonia Tanks caldera.

  6. Completion Report for Well ER-EC-1

    SciTech Connect (OSTI)

    Townsend, M.J.

    2000-12-01

    Well ER-EC-1 was drilled for the U.S. Department of Energy, Nevada Operations Office in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. This well was drilled in the spring of 1999 as part of the U.S. Department of Energy's hydrogeologic investigation well program in the Western Pahute Mesa - Oasis Valley region just west of the Test Site. A 44.5-centimeter surface hole was drilled and cased off to the depth 675.1 meters below the surface. The hole diameter was then decreased to 31.1 centimeters for drilling to a total depth of 1,524.0 meters. A preliminary composite, static, water level was measured at the depth of approximately 566.3 meters prior to installation of the completion string. One completion string with three isolated, slotted intervals was installed in the well. Detailed lithologic descriptions with preliminary stratigraphic assignments are included in the report. These are based on composite drill cuttings collected every 3 meters and 31 sidewall samples taken at various depths below 680 meters, supplemented by geophysical log data. Detailed chemical and mineralogical studies of rock samples are in progress. The well penetrated Tertiary-age lava and tuff of the Timber Mountain Group, the Paintbrush Group, the Calico Hills Formation, the Crater Flat Group, and the Volcanics of Quartz Mountain. The preliminary geologic interpretation of data from Well ER-EC-1 indicates the presence of a structural trough or bench filled with a thick section of post-Rainier Mesa lava. These data also suggest that this site is located on a buried structural ridge that may separate the Silent Canyon and Timber Mountain caldera complexes.

  7. Quarkonium Spectroscopy and New States from BaBar

    SciTech Connect (OSTI)

    Vitale, L.; /Trieste U. /INFN, Trieste

    2007-06-08

    We review results on charmonium and bottomonium spectroscopy by the BaBar experiment at the PEP-II e{sup +}e{sup -} collider at SLAC. More space is reserved to the new results like the observation of hadronic non-B{bar B} {Upsilon}(4S) decays and the investigation on the production and decay properties of the recently discovered charmonium-like states X(3872) and Y (4260). These results are preliminary, unless otherwise specified.

  8. Audit Report: ER-B-95-05 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    5 Audit Report: ER-B-95-05 July 14, 1995 Audit of Acquisition of Scientific Research at Ames Laboratory Audit Report: ER-B-95-05 (57.27 KB) More Documents & Publications Audit Report: OAS-M-05-05 Semiannual Report to Congress: April 1 to September 30, 2000 Audit Report: WR-B-96-08

  9. Audit Report: ER-B-97-01 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    1 Audit Report: ER-B-97-01 October 22, 1996 Audit of Economic Development Grants and a Cooperative Agreement with East Tennessee Not-For-Profit Organizations Audit Report: ER-B-97-01 (64.63 KB) More Documents & Publications Audit Report: CR-B-97-01 Audit Report: IG-0609 Semiannual Report to Congress: March 31, 1997

  10. Carrier transfer from InAs quantum dots to ErAs metal nanoparticles

    SciTech Connect (OSTI)

    Haughn, C. R.; Chen, E. Y.; Zide, J. M. O.; Doty, M. F.; Steenbergen, E. H.; Bissell, L. J.; Eyink, K. G.

    2014-09-08

    Erbium arsenide (ErAs) is a semi-metallic material that self-assembles into nanoparticles when grown in GaAs via molecular beam epitaxy. We use steady-state and time-resolved photoluminescence to examine the mechanism of carrier transfer between indium arsenide (InAs) quantum dots and ErAs nanoparticles in a GaAs host. We probe the electronic structure of the ErAs metal nanoparticles (MNPs) and the optoelectronic properties of the nanocomposite and show that the carrier transfer rates are independent of pump intensity. This result suggests that the ErAs MNPs have a continuous density of states and effectively act as traps. The absence of a temperature dependence tells us that carrier transfer from the InAs quantum dots to ErAs MNPs is not phonon assisted. We show that the measured photoluminescence decay rates are consistent with a carrier tunneling model.

  11. Structural and chemical characterization of BaTiO{sub 3} nanorods

    SciTech Connect (OSTI)

    Zagar, K.; Recnik, A.; Sturm, S.; Gajovic, A.; Ceh, M.

    2011-03-15

    Research highlights: {yields} Polycrystalline BaTiO{sub 3} nanorods were synthesized with EPD into AAO templates. {yields} Nanorods are composed of crystalline, nanosized grains with pseudo-cubic structure. {yields} Integrowth of hexagonal BaTiO{sub 3} polymorph within pseudo-cubic structure was observed. -- Abstract: An electron-microscopy investigation was performed on BaTiO{sub 3} nanorods that were processed by sol-gel electrophoretic deposition (EPD) into anodic aluminium oxide (AAO) membranes. The BaTiO{sub 3} nanorods grown within the template membranes had diameters ranging from 150 to 200 nm, with an average length of 10-50 {mu}m. By using various electron-microscopy techniques we showed that the processed BaTiO{sub 3} nanorods were homogeneous in their chemical composition. The BaTiO{sub 3} nanorods were always polycrystalline and were composed of well-crystallized, defect-free, pseudo-cubic BaTiO{sub 3} grains, ranging from 10 to 30 nm. No intergranular phases were observed between the BaTiO{sub 3} grains. A low-temperature hexagonal polymorph that is coherently intergrown with the BaTiO{sub 3} perovskite matrix was also observed as a minor phase. When annealing the AAO templates containing the BaTiO{sub 3} sol in an oxygen atmosphere the presence of the hexagonal polymorph was diminished.

  12. Formation, characterization and reactivity of adsorbed oxygen on BaO/Pt(111)

    SciTech Connect (OSTI)

    Mudiyanselage, Kumudu; Mei, Donghai; Yi, Cheol-Woo; Weaver, Jason F.; Szanyi, Janos

    2010-12-02

    The formation of adsorbed O (Oad) species and their reactivities in CO oxidation on BaO/Pt(111) (at two BaO coverages) were studied with temperature programmed desorption (TPD), infrared reflection absorption (IRA) and X-ray photoelectron (XP) spectroscopies. In neither of these two systems was the Pt(111) surface completely covered with BaO. On the system with lower BaO coverage (~45 % of the Pt(111) surface is covered by BaO), two different Oad species form following the adsorption of O2 at 300 K: O adsorbed on BaO-free Pt(111) sites (OPt) and at the Pt-BaO interface (Oint). On the system with higher BaO coverage (~60 % of the Pt(111) surface is covered by BaO), two types of Oint are seen at the Pt-BaO interface. The desorption of OPt from the BaO-free portion of the Pt(111) surface gives an O2 desorption peak with a maximum desorption rate at ~690 K. Migration of Oint to the Pt(111) sites and their recombinative desorption give two explosive desorption features at ~760 and ~790 K in the TPD spectrum. The reactivities of these Oad species with CO to form CO2 follow their sequence of desorption; i.e., the OPt associated with the BaO-free Pt(111) surface, which desorbs at 690 K, reacts first with CO, followed by the Oint species at the Pt-BaO interface (first the one that desorbs at ~760 K and finally the one that is bound the most strongly to the interface, and desorbs at ~790 K). This work was supported by the US Department of Energy Basic Energy Sciences' Chemical Sciences, Geosciences & Biosciences Division. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  13. Water adsorption induced in-plane domain switching on BaTiO{sub 3} surface

    SciTech Connect (OSTI)

    Li, X.; Bai, Y.; Su, Y. J.; Wang, B. C.

    2015-09-07

    In this study, the influences of the adsorption of water molecules on the changes in the atomic and electric structures of BaTiO{sub 3} surface were investigated using ab initio calculation. Water molecules are molecularly and dissociatively adsorbed on the BaTiO{sub 3} surface, which makes electrons transfer from water molecules to the BaTiO{sub 3} surface. The redistribution of electrons in the BaTiO{sub 3} surface layers weakens the Ba-O interactions and strengthens the Ti-O interactions, so that the Ti atom shifts in TiO{sub 2} plane, i.e., an in-plane domain switching. The adsorption of water molecules on BaTiO{sub 3} surfaces also results in a reduction in the surface rumpling.

  14. Ba{sub 2}TeO: A new layered oxytelluride

    SciTech Connect (OSTI)

    Besara, T.; Ramirez, D.; Sun, J.; Whalen, J.B.; Tokumoto, T.D.; McGill, S.A.; Singh, D.J.; Siegrist, T.

    2015-02-15

    Single crystals of the new semiconducting oxytelluride phase, Ba{sub 2}TeO, were synthesized from barium oxide powder and elemental tellurium in a molten barium metal flux. Ba{sub 2}TeO crystallizes in tetragonal symmetry with space group P4/nmm (#129), a=5.0337(1) Å, c=9.9437(4) Å, Z=2. The crystals were characterized by single crystal x-ray diffraction, heat capacity and optical measurements. The optical measurements along with electronic band structure calculations indicate semiconductor behavior with a band gap of 2.93 eV. Resistivity measurements show that Ba{sub 2}TeO is highly insulating. - Graphical abstract: Starting from a simple stacking of rocksalt layers, the final structure of Ba{sub 2}TeO can be obtained by accommodation of structural strain via atom displacements. Density of states calculations and optical absorbance measurements show that Ba{sub 2}TeO has a band gap of 2.93 eV, indicative of semiconductor behavior. - Highlights: • Single crystal synthesis of a new layered oxytelluride, Ba{sub 2}TeO. • The structure features inverse PbO-type BaO layers and NaCl-type BaTe layers. • Optical absorbance show Ba{sub 2}TeO to be a semiconductor with a 2.93 eV gap. • Density of states indicate a small hybridization between Te 5p and Ba 5d states. • The BaTe (BaO) layers dominate the heat capacity at low (high) temperatures.

  15. Inter-atomic force constants of BaF{sub 2} by diffuse neutron scattering measurement

    SciTech Connect (OSTI)

    Sakuma, Takashi Makhsun,; Sakai, Ryutaro; Xianglian; Takahashi, Haruyuki; Basar, Khairul; Igawa, Naoki; Danilkin, Sergey A.

    2015-04-16

    Diffuse neutron scattering measurement on BaF{sub 2} crystals was performed at 10?K and 295?K. Oscillatory form in the diffuse scattering intensity of BaF{sub 2} was observed at 295?K. The correlation effects among thermal displacements of F-F atoms were obtained from the analysis of oscillatory diffuse scattering intensity. The force constants among neighboring atoms in BaF{sub 2} were determined and compared to those in ionic crystals and semiconductors.

  16. Method of forming superconducting Tl-Ba-Ca-Cu-O films

    DOE Patents [OSTI]

    Wessels, Bruce W.; Marks, Tobin J.; Richeson, Darrin S.; Tonge, Lauren M.; Zhang, Jiming

    1993-01-01

    A method of forming a superconducting Tl-Ba-Ca-Cu-O film is disclosed, which comprises depositing a Ba-Ca-Cu-O film on a substrate by MOCVD, annealing the deposited film and heat-treating the annealed film in a closed circular vessel with TlBa.sub.2 Ca.sub.2 Cu.sub.3 O.sub.x and cooling to form said superconducting film of TlO.sub.m Ba.sub.2 Ca.sub.n-1 Cu.sub.n O.sub.2n+2, wherein m=1,2 and n=1,2,3.

  17. Completion Report for Well ER-7-1

    SciTech Connect (OSTI)

    Bechtel Nevada

    2004-11-01

    Well ER-7-1 was drilled for the U.S. Department of Energy's National Nuclear Security Administration Nevada Site Office in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. This well was drilled in January and February 2003, as part of a hydrogeologic investigation program in Yucca Flat. A 47.0-centimeter surface hole was drilled and cased off to a depth of 541.0 meters below the surface. The hole diameter was then decreased to 31.8 centimeters for drilling to a total depth of 762.0 meters. Detailed lithologic descriptions with stratigraphic assignments are included in this report. These are based on composite drill cuttings collected every 3 meters, and 62 sidewall samples taken at various depths below 85.3 meters, supplemented by geophysical log data. Detailed petrographic, chemical, and mineralogical studies were conducted on 22 samples of cuttings. The well was collared in Quaternary surficial deposits and penetrated a thick section of Tertiary-age volcanic deposits before terminating in carbonate rocks of Paleozoic-age.

  18. A A S BA IMPORTANT ISSUES W BOOK TWO O

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    i * A * A S BA IMPORTANT ISSUES W BOOK TWO O * - U.S. Department of Energy, Transition 2008 - HOT Issue Papers Section 1 - Energy 1-1 Carbon Capture and Storage (CCS) * CCS could be developed and accelerated to meet aggressive C02 emissions goals. This strategy includes FutureGen and Clean Coal Power Initiative (CCPI). * July 2009 - Select CCPI recipients (closes 1/15/09) * December 2009 - Award FutureGen based on a December 2008 selection 1-2 Next Generation Nuclear Plant (NGNP) Partnership

  19. Completion Report for Wells ER-20-8 and ER-20-8#2 Corrective Action Units 101 and 102: Central and Western Pahute Mesa

    SciTech Connect (OSTI)

    NSTec Environmental Management

    2011-02-28

    Wells ER-20-8 and ER-20-8#2 were drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of the Nevada Environmental Restoration Project at the Nevada National Security Site (formerly Nevada Test Site), Nye County, Nevada. The holes were drilled in July and August 2009, as part of the Pahute Mesa Phase II drilling program. The primary purpose of these wells was to provide detailed hydrogeologic information in the Tertiary volcanic section that will help address uncertainties within the Pahute Mesa–Oasis Valley hydrostratigraphic framework model. They may also be used as long-term monitoring wells.

  20. Audit Report: ER-B-98-02 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Audit Report: ER-B-98-02 October 24, 1997 Audit of Environmental Monitoring and Health Physics Laboratories at the Savannah River Site The Environmental Monitoring and Health...

  1. Award DE-FG02-04ER52655 Final Technical Report: Interior Point...

    Office of Scientific and Technical Information (OSTI)

    Final Technical Report: Interior Point Algorithms for Optimization Problems Citation Details In-Document Search Title: Award DE-FG02-04ER52655 Final Technical Report: Interior ...

  2. Audit Report: ER-B-95-04 | Department of Energy

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

    26, 1995 Audit of the Replacement High Level Waste Evaporator at Savannah River PDF icon Audit Report: ER-B-95-04 More Documents & Publications Inspection Report: INS-O-97-01 ...

  3. Audit Report: ER-B-98-04 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    4 Audit Report: ER-B-98-04 November 24, 1997 Audit Of Selected Government-Funded Grants And Contracts At Princeton University As the cognizant audit agency for Princeton University ...

  4. Audit Report: ER-B-98-05 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    5 Audit Report: ER-B-98-05 December 10, 1997 Audit Of The Department Of Energy's Contracts With Envirocare Of Utah, Inc The Department of Energy (Department) is responsible for ...

  5. Audit Report: ER-B-98-03 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    3 Audit Report: ER-B-98-03 November 7, 1997 Audit of the Union Valley Sample Preparation Facility at Oak Ridge In 1991, Lockheed Martin Energy Systems (Energy Systems) determined ...

  6. Audit Report: ER-B-98-01 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    1 Audit Report: ER-B-98-01 October 23, 1997 Audit of the Deactivation, Decontamination, and Disposal of Surplus Facilities at the Savannah River Site Westinghouse Savannah River ...

  7. Audit Report: ER-B-99-06 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    6 Audit Report: ER-B-99-06 April 14, 1999 Bechtel Jacobs Payroll Creation The Oak Ridge Operations Office (Operations Office) awarded a contract to the Bechtel Jacobs Company, LLC...

  8. Audit Report: ER-B-99-07 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    7 Audit Report: ER-B-99-07 May 4, 1999 Maintenance Activities at the Y-12 Plant Department of Energy (Department) policy requires the use of performance measures to assess the...

  9. Audit Report: ER-B-99-02 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    submit offers. PDF icon Audit Report: ER-B-99-02 More Documents & Publications Microsoft Word - al2004-03.doc Chapter 19 - Small Business Programs Acquisition Letter: AL2005-08...

  10. Structural and photoluminescence properties of Ce, Dy, Er-doped ZnO nanoparticles

    SciTech Connect (OSTI)

    Jayachandraiah, C.; Kumar, K. Siva; Krishnaiah, G.

    2015-06-24

    Undoped ZnO and rare earth elements (Ce, Dy and Er with 2 at. %) doped nanoparticles were synthesized by wet chemical co-precipitation method at 90°C with Polyvinylpyrrolidone (PVP) as capping agent. The structural, morphological, compositional and photoluminescence studies were performed with X-ray diffraction (XRD), Transmission electron microscopy (TEM), Energy dispersive spectroscopy (EDS), FTIR spectroscopy and Photoluminescence (PL) respectively. XRD results revealed hexagonal wurtzite structure with average particle size around 18 nm - 14 nm and are compatible with TEM results. EDS confirm the incorporation of Ce, Dy and Er elements into the host ZnO matrix and is validated by FTIR analysis. PL studies showed a broad intensive emission peak at 558 nm in all the samples. The intensity for Er- doped ZnO found maximum with additional Er shoulder peaks at 516nm and 538 nm. No Ce, Dy emission centers were found in spectra.

  11. Audit Report: ER-B-96-02 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    at Savannah River PDF icon Audit Report: ER-B-96-02 More Documents & Publications EIS-0120: Wetland Assessment Audit Report: IG-0655 EIS-0303: Draft Environmental Impact Statement

  12. Final Technical Report for DOE DE-FG02-05ER54831 "Laboratory...

    Office of Scientific and Technical Information (OSTI)

    The device works like a magnetic fi12;eld ampli12;er with a feedback circuit: the ... What is remarkable is that the same type of circuit may be achieved in a flowing ...

  13. DOE-ER-STD-6001-92; Implementation Guide for Quality Assurance...

    Office of Environmental Management (EM)

    the concepts and requirements of DOE 5700.6C into the language and practices that are ... reasonably implement the full intent of 5700.6C in the ER research community and yet ...

  14. Final Technical Report for DOE Grant DE-FG02-91ER20038 (Technical...

    Office of Scientific and Technical Information (OSTI)

    Title: Final Technical Report for DOE Grant DE-FG02-91ER20038 The existence of species within the plant genus Flaveria with differing leaf cell arrangements and photosynthetic ...

  15. FINAL REPORT Plant Physiological Aspects of Silicon DE-FG03-94ER20151

    Office of Scientific and Technical Information (OSTI)

    FINAL REPORT Plant Physiological Aspects of Silicon DE-FG03-94ER20151 Emanuel Epstein, ... Images are produced from the best available original document. Plant Physiological Aspects ...

  16. Final Technical Report: DE-FG02-08ER41562

    Office of Scientific and Technical Information (OSTI)

    Report: DE-FG02-08ER41562 (2008-2010) Discovering the Nature of Dark Energy: Towards ... R. Gibson, K. Gilmore, E. A. Grace, R. F. Green, W. J. Gressler, C. J. Grill- mair, S. ...

  17. Completion Report for Well ER-EC-2A

    SciTech Connect (OSTI)

    M. J. Townsend

    2002-03-01

    Well ER-EC-2A was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Operations Office, in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. This well was drilled in January and February of 2000 as part of a hydrogeologic investigation program in the Pahute Mesa - Oasis Valley region just west of the Nevada Test Site. A 44.5-centimeter surface hole was drilled and cased off to a depth of 412.9 meters below the surface. The hole diameter was then decreased to 31.1 centimeters for drilling to a total depth of 1,516.1 meters. One completion string with three isolated slotted intervals was installed in the well. A preliminary composite, static water level was measured at the depth of 228.0 meters, approximately two months after installation of the completion string. Detailed lithologic descriptions with preliminary stratigraphic assignments are included in this report. These are based on composite drill cuttings collected every 3 meters, and 81 sidewall samples taken at various depths below 212 meters, supplemented by geophysical log data. Detailed petrographic, chemical, and mineralogical studies of rock samples were conducted on 30 samples. The well was collared in rhyolite lava and penetrated Tertiary-age lava and tuff of the Volcanics of Fortymile Canyon and the Timber Mountain Group. The preliminary geologic interpretation of borehole data indicates that this well was drilled within the margins of the buried Rainier Mesa and Ammonia Tanks calderas, and that caldera collapse in this area was deeper than expected, resulting in a section of Volcanics of Fortymile Canyon (caldera-filling deposit) that is much thicker than expected.

  18. Completion Report for Well ER-EC-5

    SciTech Connect (OSTI)

    Bechtel Nevada

    2004-10-01

    Well ER-EC-5 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. This well was drilled in the summer of 1999 as part of the U.S. Department of Energy's hydrogeologic investigation program in the Western Pahute Mesa - Oasis Valley region just west of the Nevada Test Site. A 44.5-centimeter surface hole was drilled and cased off to a depth of 342.6 meters below ground surface. The borehole diameter was then decreased to 31.1 centimeters for drilling to a total depth of 762.0 meters. One completion string with three isolated slotted intervals was installed in the well. A preliminary composite, static water level was measured at the depth of 309.9 meters, 40 days after installation of the completion string. Detailed lithologic descriptions with stratigraphic assignments are included in the report. These are based on composite drill cuttings collected every 3 meters, and 18 sidewall samples taken at various depths below 349.6 meters, supplemented by geophysical log data and results from detailed chemical and mineralogical analyses of rock samples. The well penetrated Tertiary-age tuffs of the Thirsty Canyon Group, caldera moat-filling sedimentary deposits, lava of the Beatty Wash Formation, and landslide breccia and tuffs of the Timber Mountain Group. The well reached total depth in welded ashflow tuff of the Ammonia Tanks Tuff after penetrating 440.1 meters of this unit, which is also the main water-producing unit in the well. The geologic interpretation of data from this well constrains the western margin of the Ammonia Tanks caldera to the west of the well location.

  19. Completion Report for Well ER-12-2

    SciTech Connect (OSTI)

    Bechtel Nevada

    2004-11-01

    Well ER-12-2 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office, in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. The well was drilled from November 2002 to January 2003 as part of a hydrogeologic investigation program for the Yucca Flat Corrective Action Unit. The overall purpose of the well was to gather subsurface data to better characterize the hydrogeology in the northwestern portion of Yucca Flat. The well was drilled to total measured depth of 2,097.9 meters. The 131.1-centimeter-diameter borehole was left open (i.e., uncased) below the base of the intermediate casing at 901.6 meters. A piezometer string was installed outside the surface casing to a depth of 176.4 meters to monitor a zone of perched water. Data gathered during and shortly after hole construction include composite drill cuttings samples collected every 3 meters, sidewall core samples from 7 depths, various geophysical logs, and water level measurements. These data indicate that the well penetrated, in descending order, 137.5 meters of Quaternary and Tertiary alluvium, 48.8 meters of Tertiary volcanic rocks, 289.6 meters of Mississippian Chainman Shale, and 1,622.5 meters of Mississippian and Upper Devonian Eleana Formation consisting of shale, argillite, sandstone, quartzite, and limestone. Forty-seven days after the well was drilled the water level inside the main hole was tagged at the depth of 65.43 meters, and the water level inside the piezometer string was tagged at 127.14 meters.

  20. Completion Report for Well ER-EC-4

    SciTech Connect (OSTI)

    M. J. Townsend

    2000-09-01

    Well ER-EC-4 was drilled for the US Department of Energy, Nevada Operations Office in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. This well was drilled in the summer of 1999 as part of the U.S Department of Energy's hydrogeologic investigation well program in the Western Pahute Mesa - Oasis Valley region just west of the Test Site. A 44.5-centimeter surface hole was drilled and cased off to a depth of 263.7 meters below the surface. The hole diameter was then decreased to 31.1 centimeters for drilling to a total depth of 1,062.8 meters. One completion string with three isolated slotted intervals was installed in the well. A preliminary composite, static, water level was measured at the depth of 228.3 meters, two months after installation of the completion string. Detailed lithologic descriptions with preliminary stratigraphic assignments are included in the report. These are based on composite drill cuttings collected every 3 meters, and 35 sidewall samples taken at various depths below 286.5 meters, supplemented by geophysical log data. Detailed chemical and mineralogical studies of rock samples are in progress. The well was collared in basalt and penetrated Tertiary-age lava and tuff of the Thirsty Canyon Group, the Volcanics of Fortymile Canyon, and the Timber Mountain Group. The preliminary geologic interpretation of data from this well helps pinpoint the location of the western margin of the Timber Mountain caldera complex in the southern Nevada volcanic field.

  1. Completion Report for Well ER-EC-7

    SciTech Connect (OSTI)

    Bechtel Nevada

    2004-10-01

    Well ER-EC-7 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. This well was drilled in the summer of 1999 as part of the Department of Energy's hydrogeologic investigation program in the Western Pahute Mesa - Oasis Valley region just west of the Test Site. A 44.5-centimeter surface hole was drilled and cased off to a depth of 265.8 meters below the surface. The hole diameter was then decreased to 31.1 centimeters for drilling to a total depth of 422.5 meters. The planned depth of 762 meters was not reached due to borehole stability problems. One completion string with two isolated slotted intervals was installed in the well. A preliminary composite, static, water level was measured at the depth of 227.8 meters, 20 days after installation of the completion string. Detailed lithologic descriptions with stratigraphic assignments are included in the report. These are based on composite drill cuttings, supplemented by geophysical log data, and incorporating data from detailed chemical and mineralogical studies of rock samples. Beneath a thin alluvial deposit, the well penetrated 410 meters of lava and bedded tuff of the Volcanics of Fortymile Canyon Group, deposited in the Timber Mountain caldera moat after caldera collapse. The geologic interpretation of data from this well provides information on the thickness, lithologic composition, and hydrogeologic character of moat-filling rocks in the southern portion of the Timber Mountain caldera complex in the southwestern Nevada volcanic field.

  2. Completion report for Well ER-EC-6

    SciTech Connect (OSTI)

    M. J. Townsend

    2000-05-01

    Well ER-EC-6 was drilled for the U.S. Department of Energy, Nevada Operations Office in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. This well was drilled in the spring of 1999 as part of the DOE's hydrogeologic investigation well program in the Western Pahute Mesa - Oasis Valley region just west of the Nevada Test Site. A 66-centimeter surface hole was drilled and cased off to the depth of 485.1 meters below the surface. The hole diameter was then decreased to 31.1 centimeters for drilling to a total depth of 1,524.0 meters. A preliminary composite, static, water level was measured at the depth of approximately 434.6 meters prior to installation of the completion string. One completion string with four isolated, slotted intervals was installed in the well. Detailed lithologic descriptions with preliminary stratigraphic assignments are included in the report. These are based on composite drill cuttings collected every 3 meters and 33 sidewall samples taken at various depths below 504.4 meters, supplemented by geophysical log data. Detailed chemical and mineralogical studies of rock samples are in progress. The well penetrated Tertiary-age lava and tuff of the Timber Mountain Group, the Paintbrush Group, the Calico Hills Formation, and the Volcanics of Quartz Mountain. Intense hydrothermal alteration was observed below the depth of 640 m. The preliminary geologic interpretation indicates that this site may be located on a buried structural ridge that separates the Silent Canyon and Timber Mountain caldera complexes.

  3. Completion Report for Well ER-EC-8

    SciTech Connect (OSTI)

    Bechtel Nevada

    2004-10-01

    Well ER-EC-8 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. This well was drilled in the summer of 1999 as part of the U.S. Department of Energy's hydrogeologic investigation program in the Western Pahute Mesa - Oasis Valley region just west of the Nevada Test Site. A 44.5-centimeter surface hole was drilled and cased off to a depth of 129.8 meters below the surface. The hole diameter was then decreased to 31.1 centimeters for drilling to a total depth of 609.6 meters. One completion string with three isolated slotted intervals was installed in the well. A preliminary composite, static water level was measured at the depth of 98.4 meters, 24 days after installation of the completion string. Detailed lithologic descriptions with stratigraphic assignments are included in the report. These are based on evaluation of composite drill cuttings collected every 3 meters, and 20 sidewall samples taken at various depths below 157.9 meters, supplemented by geophysical log data and results of detailed chemical and mineralogical studies of rock samples. Drilling began in Tertiary-age tuff of the Thirsty Canyon Group, and penetrated tuffs of the Beatty Wash Formation, tuff of Buttonhook Wash, and the upper portion of the Ammonia Tanks Tuff. The geologic interpretation of data from this well helps define the location of the western margin of the Timber Mountain caldera complex in the southwestern Nevada volcanic field. Geologic and hydrologic data from the well will aid in development of models to predict groundwater flow and contaminant migration within and near the Nevada Test Site.

  4. DYNAMICAL STABILITY AND QUANTUM CHAOS OF IONS IN A LINEAR TRAP (1999002ER).

    Office of Scientific and Technical Information (OSTI)

    (Technical Report) | SciTech Connect Technical Report: DYNAMICAL STABILITY AND QUANTUM CHAOS OF IONS IN A LINEAR TRAP (1999002ER). Citation Details In-Document Search Title: DYNAMICAL STABILITY AND QUANTUM CHAOS OF IONS IN A LINEAR TRAP (1999002ER). The realization of a paradigm chaotic system, namely the harmonically driven oscillator, in the quantum domain using cold trapped ions driven by lasers is theoretically investigated. The simplest characteristics of regular and chaotic dynamics

  5. IMG ER: A System for Microbial Genome Annotation Expert Review and Curation

    SciTech Connect (OSTI)

    Markowitz, Victor M.; Mavromatis, Konstantinos; Ivanova, Natalia N.; Chen, I-Min A.; Chu, Ken; Kyrpides, Nikos C.

    2009-05-25

    A rapidly increasing number of microbial genomes are sequenced by organizations worldwide and are eventually included into various public genome data resources. The quality of the annotations depends largely on the original dataset providers, with erroneous or incomplete annotations often carried over into the public resources and difficult to correct. We have developed an Expert Review (ER) version of the Integrated Microbial Genomes (IMG) system, with the goal of supporting systematic and efficient revision of microbial genome annotations. IMG ER provides tools for the review and curation of annotations of both new and publicly available microbial genomes within IMG's rich integrated genome framework. New genome datasets are included into IMG ER prior to their public release either with their native annotations or with annotations generated by IMG ER's annotation pipeline. IMG ER tools allow addressing annotation problems detected with IMG's comparative analysis tools, such as genes missed by gene prediction pipelines or genes without an associated function. Over the past year, IMG ER was used for improving the annotations of about 150 microbial genomes.

  6. Direct spectroscopic evidence for completely filled Cu 3d shell in BaCu₂As₂ and α – BaCu₂Sb₂

    SciTech Connect (OSTI)

    Wu, S. F.; Richard, P.; van Roekeghem, A.; Nie, S. M.; Miao, H.; Xu, N.; Qian, T.; Saparov, B.; Fang, Z.; Biermann, S.; Sefat, Athena S.; Ding, H.

    2015-06-08

    We use angle-resolved photoemission spectroscopy to extract the band dispersion and the Fermi surface of BaCu₂As₂ and α - BaCu₂Sb₂. While the Cu 3d bands in both materials are located around 3.5 eV below the Fermi level, the low-energy photoemission intensity mainly comes from As 4p states, suggesting a completely filled Cu 3d shell. The splitting of the As 3d core levels and the lack of pronounced three-dimensionality in the measured band structure of BaCu₂As₂ indicate a surface state likely induced by the cleavage of this material in the collapsed tetragonal phase, which is consistent with our observation of a Cu⁺¹ oxidation state. However, the observation of Cu states at similar energy in α - BaCu₂Sb₂ without the pnictide-pnictide interlayer bonding characteristic of the collapsed tetragonal phase suggests that the short interlayer distance in BaCu₂As₂ follows from the stability of the Cu⁺¹ rather than the other way around. Our results confirm the prediction that BaCu₂As₂ is an sp metal with weak electronic correlations.

  7. Dipole strength distributions in the stable Ba isotopes {sup 134-138}Ba: A study in the mass region of a nuclear shape transition

    SciTech Connect (OSTI)

    Scheck, M.; Garrel, H. von; Belic, D.; Kneissl, U.; Kohstall, C.; Nord, A.; Pitz, H.H.; Stedile, F.; Tsoneva, N.; Brentano, P. von; Fransen, C.; Gade, A.; Jolie, J.; Linnemann, A.; Pietralla, N.; Werner, V.; Stoyanov, C.

    2004-10-01

    The low-lying dipole strength distributions in the odd-mass isotopes {sup 135,137}Ba were studied in nuclear resonance fluorescence experiments (NRF) performed at the Stuttgart Dynamitron facility using bremsstrahlung beams with end point energies of 4.1, 3.1, and 2.5 MeV. Numerous excited states, most of them unknown so far, were observed in the excitation energy range up to 4 MeV. Detailed spectroscopic information has been obtained on excitation energies, decay widths, decay branching ratios, and transition probabilities. The results for {sup 137}Ba are compared with calculations in the framework of the Quasiparticle-Phonon Model. The new data for {sup 135,137}Ba complete the systematics of low-lying dipole excitations as observed for the even Ba isotopes {sup 134,136,138}Ba in previous NRF experiments in Stuttgart. The complete systematics within the Ba isotopic chain, exhibiting a nuclear shape transition, is discussed with respect to E1 two-phonon excitations, M1 scissors mode excitations, and in regard to the new critical point symmetries.

  8. Submillimeter and microwave residual losses in epitaxial films of Y-Ba-Cu-O and Tl-Ca-Ba-Cu-O

    SciTech Connect (OSTI)

    Miller, D.; Richards, P.L.; Garrison, S.M.; Newman, N.; Eom, C.B.; Geballe, T.H.; Etemad, S.; Inam, A.; Venkatesan, T.; Martens, J.S.; Lee, W.Y.; Bourne, L.C.

    1992-03-01

    We have used a novel bolometric technique and a resonant technique to obtain accurate submillimeter and microwave residual loss data for epitaxial thin films of YBa{sub 2}Cu{sub 3}O{sub 7}, Tl{sub 2}Ca{sub 2}Ba{sub 2}Cu{sub 3}O{sub 10} and Tl{sub 2}CaBa{sub 2}Cu{sub 2}O{sub 8}. For all films we obtain good agreement between the submillimeter and microwave data, with the residual losses in both the Y-Ba-Cu-O and Tl-Ca-Ba-Cu-O films scaling approximately as frequency squared below {approximately} 1 THz. We are able to fit the losses in the Y-Ba-Cu-O films to a weakly coupled grain model for the a-b plane conductivity, in good agreement with results from a Kramers-Kronig analysis of the loss data. We observe strong phonon structure in the Tl-Ca-Ba-Cu-O films for frequencies between 2 and 21 THz, and are unable to fit these losses to the simple weakly coupled grain model. This is in strong contrast to the case for other high {Tc} superconductors such as YBa{sub 2}Cu{sub 3}O{sub 7}, where phonon structure observed in ceramic samples is absent in epitaxial oriented films and crystals because of the electronic screening due to the high conductivity of the a-b planes.

  9. Direct spectroscopic evidence for completely filled Cu 3d shell in BaCu₂As₂ and α – BaCu₂Sb₂

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wu, S. F.; Richard, P.; van Roekeghem, A.; Nie, S. M.; Miao, H.; Xu, N.; Qian, T.; Saparov, B.; Fang, Z.; Biermann, S.; et al

    2015-06-08

    We use angle-resolved photoemission spectroscopy to extract the band dispersion and the Fermi surface of BaCu₂As₂ and α - BaCu₂Sb₂. While the Cu 3d bands in both materials are located around 3.5 eV below the Fermi level, the low-energy photoemission intensity mainly comes from As 4p states, suggesting a completely filled Cu 3d shell. The splitting of the As 3d core levels and the lack of pronounced three-dimensionality in the measured band structure of BaCu₂As₂ indicate a surface state likely induced by the cleavage of this material in the collapsed tetragonal phase, which is consistent with our observation of amore » Cu⁺¹ oxidation state. However, the observation of Cu states at similar energy in α - BaCu₂Sb₂ without the pnictide-pnictide interlayer bonding characteristic of the collapsed tetragonal phase suggests that the short interlayer distance in BaCu₂As₂ follows from the stability of the Cu⁺¹ rather than the other way around. Our results confirm the prediction that BaCu₂As₂ is an sp metal with weak electronic correlations.« less

  10. Phonon properties of BaFe?X? (X=S, Se) spin ladder compounds

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Popovicq, Z. V.; Petrovic, C.; Scepanovic, M.; Lazarevic, N.; Opacic, M.; Radonjic, M. M.; Tanaskovic, D.; Lei, Hechang

    2015-02-27

    We present the Raman scattering spectra of the S=2 spin ladder compounds BaFe?X? (X=S,Se) in a temperature range between 20 and 400 K. Although the crystal structures of these two compounds are both orthorhombic and very similar, they are not isostructural. The unit cell of BaFe?S? (BaFe?Se?) is base-centered Cmcm (primitive Pnma), giving 18 (36) modes to be observed in the Raman scattering experiment. We have detected almost all Raman active modes, predicted by factor group analysis, which can be observed from the cleavage planes of these compounds. Assignment of the observed Raman modes of BaFe?S(Se)? is supported by themorelattice dynamics calculations. The antiferromagnetic long-range spin ordering in BaFe?Se? below TN=255K leaves a fingerprint both in the A1g and B3g phonon mode linewidth and energy.less

  11. Nanocrystalline BaTiO3 powder via ambient conditions sol process (Prop.2001-071)

    SciTech Connect (OSTI)

    Payzant, E Andrew; Wang, X.; Hu, Michael Z.; Blom, Douglas Allen

    2005-01-01

    Nanocrystalline BaTiO{sub 3} particles have been prepared by ambient condition sol (ACS) process starting from soluble precursors of barium and titanium yielding a mixed oxide/hydroxide gel. The gel was peptized and crystallized in water under a refluxing condition. Higher initial pH and Ba/Ti ratio led to smaller crystallite sizes of BaTiO{sub 3} powders. Organic mineralizer, tetramethylammonium hydroxide (TMAH), can adsorb on the BaTiO{sub 3} nuclei and inhibited further growth of the particles. Adding a polymer during BaTiO{sub 3} synthesis led to a smaller particle size and increased redispersibility of the particles in water.

  12. Pahute Mesa Well Development and Testing Analyses for Wells ER-20-8 and ER-20-4, Nevada National Security Site, Nye County, Nevada, Revision 0

    SciTech Connect (OSTI)

    Greg Ruskauff and Sam Marutzky

    2012-09-01

    Wells ER-20-4 and ER-20-8 were drilled during fiscal year (FY) 2009 and FY 2010 (NNSA/NSO, 2011a and b). The closest underground nuclear test detonations to the area of investigation are TYBO (U-20y), BELMONT (U-20as), MOLBO (U-20ag), BENHAM (U-20c), and HOYA (U-20 be) (Figure 1-1). The TYBO, MOLBO, and BENHAM detonations had working points located below the regional water table. The BELMONT and HOYA detonation working points were located just above the water table, and the cavity for these detonations are calculated to extend below the water table (Pawloski et al., 2002). The broad purpose of Wells ER-20-4 and ER-20-8 is to determine the extent of radionuclide-contaminated groundwater, the geologic formations, groundwater geochemistry as an indicator of age and origin, and the water-bearing properties and hydraulic conditions that influence radionuclide migration. Well development and testing is performed to determine the hydraulic properties at the well and between other wells, and to obtain groundwater samples at the well that are representative of the formation at the well. The area location, wells, underground nuclear detonations, and other features are shown in Figure 1-1. Hydrostratigraphic cross sections A-A, B-B, C-C, and D-D are shown in Figures 1-2 through 1-5, respectively.

  13. Catalytic decomposition of Ba(NO3)2 on Pt(111)

    SciTech Connect (OSTI)

    Mudiyanselage, Kumudu; Weaver, Jason F.; Szanyi, Janos

    2011-04-07

    The decomposition of Ba(NO3)2 formed on BaO/Pt(111) (Pt(111) surface is partially covered by BaO) in the presence of CO was studied using temperature programmed desorption (TPD), infrared reflection absorption (IRA) and X-ray photoelectron (XP) spectroscopies. The exposure of BaO/Pt(111) to elevated NO2 pressure (1.0×10-4 Torr) at 450 K leads to the formation of Ba(NO3)2, chemisorbed O (OPt) and Pt-oxide-like domains. During TPD, the Ba(NO3)2 begins to thermally decompose near 490 K, releasing NO and NO2 with the maximum NOx desorption rate seen at 605 K. The OPt species formed following the exposure of BaO/Pt(111) to NO2 react with CO to release CO2 at 450 K. The consumption of OPt during CO oxidation initiates the migration of O from the Pt-oxide-like domains to the chemisorbed phase, where the CO oxidation reaction occurs. Therefore, the removal of OPt by CO leads to the reduction of oxidized Pt, and to the formation of metallic Pt(111) domains, where, subsequently, catalytic decomposition of Ba(NO3)2 can take place. The Pt-catalyzed decomposition of Ba(NO3)2 occurs readily at 450 K, a temperature much lower than the onset of the decomposition temperature of Ba(NO3)2 in the presence of oxidized Pt. This work was supported by the US Department of Energy Basic Energy Sciences' Chemical Sciences, Geosciences & Biosciences Division. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  14. Excitation mechanisms of Er optical centers in GaN epilayers

    SciTech Connect (OSTI)

    George, D. K.; Hawkins, M. D.; McLaren, M.; Vinh, N. Q.; Jiang, H. X.; Lin, J. Y.; Zavada, J. M.

    2015-10-26

    We report direct evidence of two mechanisms responsible for the excitation of optically active Er{sup 3+} ions in GaN epilayers grown by metal-organic chemical vapor deposition. These mechanisms, resonant excitation via the higher-lying inner 4f shell transitions and band-to-band excitation of the semiconductor host, lead to narrow emission lines from isolated and the defect-related Er optical centers. However, these centers have different photoluminescence spectra, local defect environments, decay dynamics, and excitation cross sections. The photoluminescence at 1.54 μm from the isolated Er optical center which can be excited by either mechanism has the same decay dynamics, but possesses a much higher excitation cross-section under band-to-band excitation. In contrast, the photoluminescence at 1.54 μm from the defect-related Er optical center can only be observed through band-to-band excitation but has the largest excitation cross-section. These results explain the difficulty in achieving gain in Er doped GaN and indicate approaches for realization of optical amplification, and possibly lasing, at room temperature.

  15. Y-Ba-Cu-O films prepared by a paint-on method

    SciTech Connect (OSTI)

    Shih, I.; Qiu, C.X.

    1988-02-29

    Polycrystalline films of Y-Ba-Cu-O with a thickness of about 20--40 ..mu..m have been prepared on alumina substrates using a paint-on method. The liquid source used was obtained by mixing powder of Y/sub 2/O/sub 3/, BaCO/sub 3/, and CuO in liquid triethanolamine. Several Y-Ba-Cu-O films with an onset temperature of about 100 K and a zero resistance temperature of 85 K have been obtained after a short heat treatment at 1000 /sup 0/C in flowing O/sub 2/.

  16. Thickness dependence of hydrogen permeability for Ni-BaCe{sub...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Thickness dependence of hydrogen permeability for Ni-BaCesub 0.8Ysub 0.2Osub 3-delta. Citation Details In-Document Search Title: Thickness dependence of ...

  17. Ba{sub 2}TeO as an optoelectronic material: First-principles study

    SciTech Connect (OSTI)

    Sun, Jifeng; Shi, Hongliang; Du, Mao-Hua; Singh, David J.; Siegrist, Theo

    2015-05-21

    The band structure, optical, and defects properties of Ba{sub 2}TeO are systematically investigated using density functional theory with a view to understanding its potential as an optoelectronic or transparent conducting material. Ba{sub 2}TeO crystallizes with tetragonal structure (space group P4/nmm) and with a 2.93 eV optical bandgap [Besara et al., J. Solid State Chem. 222, 60 (2015)]. We find relatively modest band masses for both electrons and holes suggesting applications. Optical properties show infrared-red absorption when doped. This could potentially be useful for combining wavelength filtering and transparent conducting functions. Furthermore, our defect calculations show that Ba{sub 2}TeO is intrinsically p-type conducting under Ba-poor condition. However, the spontaneous formation of the donor defects may constrain the p-type transport properties and would need to be addressed to enable applications.

  18. Fermi surfaces and phase stability of Ba( Fe 1 - x M x ) 2 As...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Fermi surfaces and phase stability of Ba( Fe 1 - x M x ) 2 As 2 ( M Co ... Resource Relation: Journal Name: Physical Review. B, Condensed Matter and Materials ...

  19. Morphology and Composition cycle of BaO/Al2O3 NSR Catalysts during...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    spectroscopy and microscopy study Morphology and Composition cycle of BaOAl2O3 NSR Catalysts during NO2 Uptake and Release: A multi spectroscopy and microscopy study 2005 Diesel ...

  20. Ba2TeO as an optoelectronic material: First-principles study

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Sun, Jifeng; Shi, Hongliang; Du, Mao-Hua; Siegrist, Theo; Singh, David J.

    2015-05-21

    The band structure, optical and defects properties of Ba2TeO are systematically investigated using density functional theory with a view to understanding its potential as an optoelectronic or transparent conducting material. Ba2TeO crystallizes with tetragonal structure (space group P4/nmm) and with a 2.93 eV optical band gap1. We find relatively modest band masses for both electrons and holes suggesting applications. Optical properties show a infrared-red absorption when doped. This could potentially be useful for combining wavelength filtering and transparent conducting functions. Furthermore, our defect calculations show that Ba2TeO is intrinsically p-type conducting under Ba-poor condition. However, the spontaneous formation of themore » donor defects may constrain the p-type transport properties and would need to be addressed to enable applications.« less

  1. The U5+ compound Ba9Ag10U4S24: Synthesis, structure, and electronic...

    Office of Scientific and Technical Information (OSTI)

    The U5+ compound Ba9Ag10U4S24: Synthesis, structure, and electronic properties This ... Sponsoring Org: USDOE Country of Publication: United States Language: English Word Cloud ...

  2. Observation in BaBar of a Narrow Resonance in the D{sub s} pi...

    Office of Scientific and Technical Information (OSTI)

    in the Dsub s pisup 0 System at 2317 MeVcsup 2 Citation Details In-Document Search Title: Observation in BaBar of a Narrow Resonance in the Dsub s pisup 0 System at ...

  3. Chiral Anomaly Effects And the BaBar Measurements of the$\\gamma...

    Office of Scientific and Technical Information (OSTI)

    ...to pi0 Transition Form Factor Citation Details In-Document Search Title: Chiral Anomaly Effects And the BaBar Measurements of the gammagamma*to pi0 ...

  4. NO2 uptake under practically relevant conditions on BaO/Pt(111)

    SciTech Connect (OSTI)

    Mudiyanselage, Kumudu K.; Szanyi, Janos

    2012-02-14

    The formation of nitrites and nitrates (Ba(NOx)2) under practically relevant conditions (PNO2 up to 1.0 Torr and T = 500 K) and their thermal decomposition on BaO (>20 monolayer equivalent (MLE))/Pt(1 1 1) were studied using temperature programmed desorption (TPD), infrared reflection absorption (IRA), and Xray photoelectron (XP) spectroscopies. The exposure of BaO to 1.0 × 10−8 Torr NO2 at 500 K leads to the formation of a Ba(NOx)2 layer with small, disordered crystalline nitrate clusters. Under these conditions (PNO2 = 1.0 × 10−8 Torr and T = 500 K) only the top portion of the BaO layer converts to Ba(NOx)2 and the nitrites in this Ba(NOx)2 layer stay without converting completely to nitrates even after 100 min of NO2 exposure. In the thermal decomposition of Ba(NOx)2, first nitrites decompose, releasing NO and then the decomposition of nitrates occurs via two pathways releasing NO2 and NO + O2. At 500 K and PNO2 ≥ 1.0 × 10−7 Torr, first NO2 reacts with BaO to form small disordered crystalline Ba(NO3)2 particles and then these particles agglomerate to form large, well-ordered (bulk-like) crystalline nitrates as the NO2 exposure increases. The thermal decomposition of these well-ordered, bulk-like crystalline nitrate aggregates occurs in two steps releasing NO2 and NO + O2 in each step in two different temperature regions. NO2 pressure ≥1.0 × 10−5 Torr is required for the complete oxidation of initially formed nitrites to nitrates and the full nitration of the BaO layer at 500 K sample temperature. We gratefully acknowledge the US Department of Energy (DOE), Office of Basic Energy Sciences, Division of Chemical Sciences for the support of this work. The research described in this paper was performed at the Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by the DOE Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory (PNNL). PNNL is operated for the US

  5. Building America Team (BA-PIRC) - 2014 BTO Peer Review | Department of

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Energy BA-PIRC) - 2014 BTO Peer Review Building America Team (BA-PIRC) - 2014 BTO Peer Review Presenter: Eric Martin, Florida Solar Energy Center Building America research projects develop and demonstrate market-ready building solutions that improve the energy efficiency of new and existing homes, increasing comfort, health, safety, and durability. When fully deployed, proven solutions will reduce building-related energy use in new and existing residential building stock by 30% and 25%,

  6. Crystallography and Physical Properties of BaCo2As2, Ba0.94K0.06Co2As2, and Ba0.78K0.22Co2As2

    SciTech Connect (OSTI)

    Anand, V K; Quirinale, Dante G; Lee, Yongbin; Harmon, Bruce N; Furukawa, Yuji; Ogloblichev, V V; Huq, A; Abernathy, D L; Stephens, P W; McQueeney, Robert J; Kreyssig, Aandreas; Goldman, Alan I; Johnston, David C

    2014-08-01

    The crystallographic and physical properties of polycrystalline and single crystal samples of BaCo2As2 and K-doped Ba{1-x}K{x}Co2As2 (x = 0.06, 0.22) are investigated by x-ray and neutron powder diffraction, magnetic susceptibility chi, magnetization, heat capacity Cp, {75}As NMR and electrical resistivity rho measurements versus temperature T. The crystals were grown using both Sn flux and CoAs self-flux, where the Sn-grown crystals contain 1.6-2.0 mol% Sn. All samples crystallize in the tetragonal ThCr2Si2-type structure (space group I4/mmm). For BaCo2As2, powder neutron diffraction data show that the c-axis lattice parameter exhibits anomalous negative thermal expansion from 10 to 300 K, whereas the a-axis lattice parameter and the unit cell volume show normal positive thermal expansion over this T range. No transitions in BaCo2As2 were found in this T range from any of the measurements. Below 40-50 K, we find rho ~ T^2 indicating a Fermi liquid ground state. A large density of states at the Fermi energy D(EF) ~ 18 states/(eV f.u.) for both spin directions is found from low-T Cp(T) measurements, whereas the band structure calculations give D(EF) = 8.23 states/(eV f.u.). The {75}As NMR shift data versus T have the same T dependence as the chi(T) data, demonstrating that the derived chi(T) data are intrinsic. The observed {75}As nuclear spin dynamics are consistent with the presence of ferromagnetic and/or stripe-type antiferromagnetic spin fluctuations. The crystals of Ba{0.78}K{0.22}Co2As2 were grown in Sn flux and show properties very similar to those of undoped BaCo2As2. On the other hand, the crystals from two batches of Ba{0.94}K{0.06}Co2As2 grown in CoAs self-flux show evidence of weak ferromagnetism at T < 10 K with small ordered moments at 1.8 K of 0.007 and 0.03 muB per formula unit, respectively.

  7. 137 Ba Double Gamma Decay Measurement with GAMMASPHERE

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Merchán, E.; Moran, K.; Lister, C. J.; Chowdhury, P.; McCutchan, E. A.; Greene, J. P.; Zhu, S.; Lauritsen, T.; Carpenter, M. P.; Shearman, R.

    2015-05-28

    The study of the electromagnetic moments (EM), and decay probability, provides detailed information about nuclear wave functions. The well-know properties of EM interactions are good for extracting information about the motion of nucleons. Higher order EM processes always occur, but are usually too weak to be measured. In the case of a 0+ → 0+ transitions, where a single gamma transition is forbidden, the simultaneous emission of two γ-rays has been studied. An interesting opportunity to further investigate 2-photon emission phenomena is by using a standard 137Cs source populating, via β-decay, the Jπ = 11/2- isomeric state at 662 keVmore » in 137Ba. In this case, two photon process can have contributions from quadrupole-quadrupole or dipole-octupole multipolarities in direct competition with the high multipolarity M4 decay. Since the yield of the double gamma decay is around six orders of magnitude less than the first order transition, very good statistics are needed in order to observe the phenomena and great care must be taken to suppress the first-order decay. The Gammasphere array is ideal since its configuration allows a good coverage of the angular distribution and the Compton events can be suppressed. Nevertheless the process to understand and eliminate the Compton background is a challenge. Geant4 simulations were carried out to help understand and correct for those factors.« less

  8. 137 Ba Double Gamma Decay Measurement with GAMMASPHERE

    SciTech Connect (OSTI)

    Merchn, E.; Moran, K.; Lister, C. J.; Chowdhury, P.; McCutchan, E. A.; Greene, J. P.; Zhu, S.; Lauritsen, T.; Carpenter, M. P.; Shearman, R.

    2015-05-28

    The study of the electromagnetic moments (EM), and decay probability, provides detailed information about nuclear wave functions. The well-know properties of EM interactions are good for extracting information about the motion of nucleons. Higher order EM processes always occur, but are usually too weak to be measured. In the case of a 0+ ? 0+ transitions, where a single gamma transition is forbidden, the simultaneous emission of two ?-rays has been studied. An interesting opportunity to further investigate 2-photon emission phenomena is by using a standard 137Cs source populating, via ?-decay, the J? = 11/2- isomeric state at 662 keV in 137Ba. In this case, two photon process can have contributions from quadrupole-quadrupole or dipole-octupole multipolarities in direct competition with the high multipolarity M4 decay. Since the yield of the double gamma decay is around six orders of magnitude less than the first order transition, very good statistics are needed in order to observe the phenomena and great care must be taken to suppress the first-order decay. The Gammasphere array is ideal since its configuration allows a good coverage of the angular distribution and the Compton events can be suppressed. Nevertheless the process to understand and eliminate the Compton background is a challenge. Geant4 simulations were carried out to help understand and correct for those factors.

  9. Measurements of the CKM Angle Alpha at BaBar

    SciTech Connect (OSTI)

    Stracka, Simone; /Milan U. /INFN, Milan

    2012-04-04

    The authors present improved measurements of the branching fractions and CP-asymmetries fin the B{sup 0} {yields} {pi}{sup +}{pi}{sup -}, B{sup 0} {yields} {pi}{sup 0}{pi}{sup 0}, and B{sup +} {yields} {rho}{sup +}{rho}{sup 0} decays, which impact the determination of {alpha}. The combined branching fractions of B {yields} K{sub 1}(1270){pi} and B {yields} K{sub 1}(1400){pi} decays are measured for the first time and allow a novel determination of {alpha} in the B{sup 0} {yields} {alpha}{sub 1}(1260){sup {+-}}{pi}{sup {-+}} decay channel. These measurements are performed using the final dataset collected by the BaBar detector at the PEP-II B-factory. The primary goal of the experiments based at the B factories is to test the Cabibbo-Kobayashi-Maskawa (CKM) picture of CP violation in the standard model of electroweak interactions. This can be achieved by measuring the angles and sides of the Unitarity Triangle in a redundant way.

  10. The photoluminescence properties of Er{sup 3+}-doped ZrO{sub 2} nanotube arrays prepared by anodization

    SciTech Connect (OSTI)

    Wang, Xixin; Zhao, Jianling; Du, Peng; Guo, Limin; Xu, Xuewen; Tang, Chengchun

    2012-11-15

    Graphical abstract: Display Omitted Highlights: ? Er{sup 3+}-doped ZrO{sub 2} nanotube arrays were prepared by anodization of ZrEr alloy. ? Small tetragonal zirconia crystallites are tended to be formed due to the doping of Er{sup 3+}. ? Under excitation at 317 nm, the ZrO{sub 2} nantube arrays have strongest photoluminescence intensity. -- Abstract: Er{sup 3+}-doped ZrO{sub 2} nanotube arrays were prepared by anodization of ZrEr alloy which was obtained by melting zirconium with 1.0 wt% erbium. The morphology, structure and photoluminescence properties were studied through scanning electron microscope, transmission electron microscope, X-ray diffraction and photoluminescence analyzer. X-ray diffraction results indicate that doping of Er{sup 3+} affects the crystal structure and grain size obviously and the Er{sup 3+}-doped samples tend to form small tetragonal grains. Photoluminescence analyses show that when Er{sup 3+}-doped zirconia nanotube arrays are excited at 317 nm, there are two strong photoluminescence emission peaks at 373 nm and 415 nm. When the excitation wavelength is 257 nm, a photoluminescence emission peak appears at 363 nm. Under same measurement conditions, emission peaks of the undoped ZrO{sub 2} nanotube arrays are very weak.

  11. Final Report on Research Conducted under Grant DE-FG02-98ER14857

    SciTech Connect (OSTI)

    Carpenter, Barry,K.; Davis, H., Floyd

    2008-01-28

    Work in the Carpenter laboratory under the aegis of grant DE-FG02-98ER14857 concerned the formation, properties, and reactions of organic free radicals known or believed to be important in hydrocarbon combustion. Both computational and experimental methods were employed in these studies.

  12. FOEU-iERLY UTILIZED SITES REKEDIAL ACTION PROG%AM ELIMINATION REPORT

    Office of Legacy Management (LM)

    y ((-' q ' c - ,' .* FOEU-iERLY UTILIZED SITES REKEDIAL ACTION PROG%AM ELIMINATION REPORT FORMERERATOOLAND ENGINEERING COMPANY 4555 UEST ADDISON STREET CHICAGO, ILLINOIS NOVEMBER 14, 1989 Department of Energy Office of Nuclear Energy Office of Remedial Action and Waste Technology Facility and Site Decommissioning . . CONTENTS Page INTRODU~ION......................... 1 BAcI(GROuND.......................... 1 Site Function. ...................... 1 Site Description ..................... 2

  13. Effect of Er doping on the structural and magnetic properties of cobalt-ferrite

    SciTech Connect (OSTI)

    Prathapani, Sateesh; Vinitha, M.; Das, D.; Jayaraman, T. V.

    2014-05-07

    Nanocrystalline particulates of Er doped cobalt-ferrites CoFe{sub (2−x)}Er{sub x}O{sub 4} (0 ≤ x ≤ 0.04), were synthesized, using sol-gel assisted autocombustion method. Co-, Fe-, and Er- nitrates were the oxidizers, and malic acid served as a fuel and chelating agent. Calcination (400–600 °C for 4 h) of the precursor powders was followed by sintering (1000 °C for 4 h) and structural and magnetic characterization. X-ray diffraction confirmed the formation of single phase of spinel for the compositions x = 0, 0.01, and 0.02; and for higher compositions an additional orthoferrite phase formed along with the spinel phase. Lattice parameter of the doped cobalt-ferrites was higher than that of pure cobalt-ferrite. The observed red shift in the doped cobalt-ferrites indicates the presence of induced strain in the cobalt-ferrite matrix due to large size of the Er{sup +3} compared to Fe{sup +3}. Greater than two-fold increase in coercivity (∼66 kA/m for x = 0.02) was observed in doped cobalt-ferrites compared to CoFe{sub 2}O{sub 4} (∼29 kA/m)

  14. Infrared spectroscopy of CaTiO3, SrTiO3, BaTiO3, Ba0.5Sr0.5TiO3...

    Office of Scientific and Technical Information (OSTI)

    Infrared spectroscopy of CaTiO3, SrTiO3, BaTiO3, Ba0.5Sr0.5TiO3 thin films, and (BaTiO3)5(SrTiO3)5 superlattice grown on SrRuO3SrTiO3(001) substrates Citation Details In-Document ...

  15. Work Function Reduction by BaO: Growth of Crystalline Barium Oxide on Ag(001) and Ag(111) Surfaces

    SciTech Connect (OSTI)

    Droubay, Timothy C.; Kong, Lingmei; Chambers, Scott A.; Hess, Wayne P.

    2015-02-01

    Ultrathin films of barium oxide were grown on Ag(001) and Ag(111) using the evaporation of Ba metal in an O2 atmosphere by molecular beam epitaxy. Ultraviolet photoemission spectroscopy reveals that films consisting of predominantly BaO or BaO2 result in Ag(001) work function reductions of 1.74 eV and 0.64 eV, respectively. On the Ag(001) surface, Ba oxide growth is initiated by two-dimensional nucleation of epitaxial BaO, followed by a transition to three-dimensional dual-phase nucleation of epitaxial BaO and BaO2. Three-dimensional islands of primarily BaO2(111) nucleate epitaxially on the Ag(111) substrate leaving large patches of Ag uncovered. We find no indication of chemical reaction or charge transfer between the films and the Ag substrates. These data suggest that the origin of the observed work function reduction is largely due to a combination of BaO surface relaxation and an electrostatic compressive effect.

  16. Significant increase of Curie temperature in nano-scale BaTiO{sub 3}

    SciTech Connect (OSTI)

    Li, Yueliang; Liao, Zhenyu; Fang, Fang; Zhu, Jing; Wang, Xiaohui; Li, Longtu

    2014-11-03

    The low Curie temperature (T{sub c}?=?130?C) of bulk BaTiO{sub 3} greatly limits its applications. In this work, the phase structures of BaTiO{sub 3} nanoparticles with sizes ranging from 2.5?nm to 10?nm were studied at various temperatures by using aberration-corrected transmission electron microscopy (TEM) equipped with an in-situ heating holder. The results implied that each BaTiO{sub 3} nanoparticle was composed of different phases, and the ferroelectric ones were observed in the shells due to the complicated surface structure. The ferroelectric phases in BaTiO{sub 3} nanoparticles remained at 600?C, suggesting a significant increase of T{sub c}. Based on the in-situ TEM results and the data reported by others, temperature-size phase diagrams for BaTiO{sub 3} particles and ceramics were proposed, showing that the phase transition became diffused and the T{sub c} obviously increased with decreasing size. The present work sheds light on the design and fabrication of advanced devices for high temperature applications.

  17. Lattice dynamics of BaFe2X3(X=S,Se) compounds

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Popović, Z. V.; Šćepanović, M.; Lazarević, N.; Opačić, M.; Radonjić, M. M.; Tanasković, D.; Lei, Hechang; Petrovic, C.

    2015-02-27

    We present the Raman scattering spectra of the S=2 spin ladder compounds BaFe₂X₃ (X=S,Se) in a temperature range between 20 and 400 K. Although the crystal structures of these two compounds are both orthorhombic and very similar, they are not isostructural. The unit cell of BaFe₂S₃ (BaFe₂Se₃) is base-centered Cmcm (primitive Pnma), giving 18 (36) modes to be observed in the Raman scattering experiment. We have detected almost all Raman active modes, predicted by factor group analysis, which can be observed from the cleavage planes of these compounds. Assignment of the observed Raman modes of BaFe₂S(Se)₃ is supported by themore » lattice dynamics calculations. The antiferromagnetic long-range spin ordering in BaFe₂Se₃ below TN=255K leaves a fingerprint both in the A1g and B3g phonon mode linewidth and energy.« less

  18. Investigation of the {sup 128}Ba nucleus with the (p,t) reaction

    SciTech Connect (OSTI)

    Pascu, S.; Cata-Danil, Gh.; Bucurescu, D.; Marginean, N.; Zamfir, N. V.; Graw, G.; Gollwitzer, A.; Hofer, D.; Valnion, B. D.

    2009-06-15

    The low lying states in {sup 128}Ba have been investigated for the first time with the {sup 130}Ba(p,t){sup 128}Ba reaction. The experiment was performed at the Munich Q3D magnetic spectrograph with a 25-MeV proton beam and a high-resolution, 1.5-m-long focal plane detector. As a result of this experiment 27 excited levels with energies below 3.7 MeV have been observed for the first time, significantly increasing (by {approx}50%) the number of levels observed in {sup 128}Ba. Angular distributions of tritons were measured and their comparison with the distorted wave Born approximation calculation allowed in most cases spin and parity assignments for the nuclear levels. The experimental two-neutron transition strengths with transferred angular momentum L=0 and 2 are compared with the predictions of the IBA-1 model with a new set of parameters. The results indicate for the first time from a hadronic probe perspective a transitional structure close to the O(6) symmetry for the {sup 128}Ba nucleus, confirming previous conclusions of {gamma}-ray spectroscopy studies.

  19. Microstructure and Cs Behavior of Ba-Doped Aluminosilicate Pollucite Irradiated with F+ Ions

    SciTech Connect (OSTI)

    Jiang, Weilin; Kovarik, Libor; Zhu, Zihua; Varga, Tamas; Engelhard, Mark H.; Bowden, Mark E.; Nenoff, Tina M.; Garino, Terry

    2014-08-07

    Radionuclide 137Cs is one of the major fission products that dominate heat generation in spent fuels over the first 300 hundred years. A durable waste form for 137Cs that decays to 137Ba is needed to minimize its environmental impact. Aluminosilicate pollucite CsAlSi2O6 is selected as a model waste form to study the decay-induced structural effects. While Ba-containing precipitates are not present in charge-balanced Cs0.9Ba0.05AlSi2O6, they are found in Cs0.9Ba0.1AlSi2O6 and identified as monoclinic Ba2Si3O8. Pollucite is susceptible to electron irradiation induced amorphization. The threshold density of the electronic energy deposition for amorphization is determined to be ~235 keV/nm3. Pollucite can be readily amorphized under F+ ion irradiation at 673 K. A significant amount of Cs diffusion and release from the amorphized pollucite is observed during the irradiation. However, cesium is immobile in the crystalline structure under He+ ion irradiation at room temperature. The critical temperature for amorphization is not higher than 873 K under F+ ion irradiation. If kept at or above 873 K all the time, the pollucite structure is unlikely to be amorphized; Cs diffusion and release are improbable. A general discussion regarding pollucite as a potential waste form is provided in this report.

  20. Hybrid molecular beam epitaxy for the growth of stoichiometric BaSnO{sub 3}

    SciTech Connect (OSTI)

    Prakash, Abhinav Dewey, John; Yun, Hwanhui; Jeong, Jong Seok; Mkhoyan, K. Andre; Jalan, Bharat

    2015-11-15

    Owing to its high room-temperature electron mobility and wide bandgap, BaSnO{sub 3} has recently become of significant interest for potential room-temperature oxide electronics. A hybrid molecular beam epitaxy (MBE) approach for the growth of high-quality BaSnO{sub 3} films is developed in this work. This approach employs hexamethylditin as a chemical precursor for tin, an effusion cell for barium, and a radio frequency plasma source for oxygen. BaSnO{sub 3} films were thus grown on SrTiO{sub 3} (001) and LaAlO{sub 3} (001) substrates. Growth conditions for stoichiometric BaSnO{sub 3} were identified. Reflection high-energy electron diffraction (RHEED) intensity oscillations, characteristic of a layer-by-layer growth mode were observed. A critical thickness of ∼1 nm for strain relaxation was determined for films grown on SrTiO{sub 3} using in situ RHEED. Scanning transmission electron microscopy combined with electron energy-loss spectroscopy and energy dispersive x-ray spectroscopy confirmed the cube-on-cube epitaxy and composition. The importance of precursor chemistry is discussed in the context of the MBE growth of BaSnO{sub 3}.

  1. Population dynamics in epitaxial Er{sub 2}O{sub 3} thin films grown on Si(111)

    SciTech Connect (OSTI)

    Tawara, T.; Omi, H.; Hozumi, T.; Kaji, R.; Adachi, S.; Gotoh, H.; Sogawa, T.

    2013-06-17

    We grow single crystal erbium-oxide (Er{sub 2}O{sub 3}) epitaxially on a Si (111) substrate by using molecular beam epitaxy and investigate the population dynamics in Er{sup 3+} ions for the coherent manipulation of the population in Er{sub 2}O{sub 3}. Sharp and discrete Stark energy levels of the {sup 4}I{sub 13/2} manifold as small as 200 {mu}eV are observed with inhomogeneous broadening caused by the uniform crystal field of the epitaxial Er{sub 2}O{sub 3}. We also experimentally determine the time constant of the resonant population transfer between spatially distant Er{sup 3+}-ion sites, which is limited to the manipulation time of the population in the Er{sub 2}O{sub 3} crystals. Using selective excitation of the Stark level in the {sup 4}I{sub 13/2} manifold, we obtain the energy transfer times between spatially distant Er{sup 3+} ions, and they are about 2 {mu}s between sites whose crystallographic symmetry is different and 10 {mu}s between sites whose symmetry is the same.

  2. Ba2TeO: A new layered oxytelluride

    SciTech Connect (OSTI)

    Besara, T.; Ramirez, D.; Sun, J.; Whalen, J. B.; Tokumoto, T. D.; McGill, S. A.; Singh, D. J.; Siegrist, T.

    2015-02-01

    For single crystals of the new semiconducting oxytelluride phase, Ba2TeO, we synthesized from barium oxide powder and elemental tellurium in a molten barium metal flux. Ba2TeO crystallizes in tetragonal symmetry with space group P4/nmm (#129), a=5.0337(1) Å, c=9.9437(4) Å, Z=2. The crystals were characterized by single crystal x-ray diffraction, heat capacity and optical measurements. Moreover, the optical measurements along with electronic band structure calculations indicate semiconductor behavior with a band gap of 2.93 eV. Resistivity measurements show that Ba2TeO is highly insulating.

  3. High-mobility BaSnO{sub 3} grown by oxide molecular beam epitaxy

    SciTech Connect (OSTI)

    Raghavan, Santosh; Schumann, Timo; Kim, Honggyu; Zhang, Jack Y.; Cain, Tyler A.; Stemmer, Susanne

    2016-01-01

    High-mobility perovskite BaSnO{sub 3} films are of significant interest as new wide bandgap semiconductors for power electronics, transparent conductors, and as high mobility channels for epitaxial integration with functional perovskites. Despite promising results for single crystals, high-mobility BaSnO{sub 3} films have been challenging to grow. Here, we demonstrate a modified oxide molecular beam epitaxy (MBE) approach, which supplies pre-oxidized SnO{sub x}. This technique addresses issues in the MBE of ternary stannates related to volatile SnO formation and enables growth of epitaxial, stoichiometric BaSnO{sub 3}. We demonstrate room temperature electron mobilities of 150 cm{sup 2} V{sup −1} s{sup −1} in films grown on PrScO{sub 3}. The results open up a wide range of opportunities for future electronic devices.

  4. Photonic crystal light emitting diode based on Er and Si nanoclusters co-doped slot waveguide

    SciTech Connect (OSTI)

    Lo Savio, R.; Galli, M.; Liscidini, M.; Andreani, L. C.; Franz, G.; Iacona, F.; Miritello, M.; Irrera, A.; Sanfilippo, D.; Piana, A.; Priolo, F.

    2014-03-24

    We report on the design, fabrication, and electro-optical characterization of a light emitting device operating at 1.54??m, whose active layer consists of silicon oxide containing Er-doped Si nanoclusters. A photonic crystal (PhC) is fabricated on the top-electrode to enhance the light extraction in the vertical direction, and thus the external efficiency of the device. This occurs if a photonic mode of the PhC slab is resonant with the Er emission energy, as confirmed by theoretical calculations and experimental analyses. We measure an increase of the extraction efficiency by a factor of 3 with a high directionality of light emission in a narrow vertical cone. External quantum efficiency and power efficiency are among the highest reported for this kind of material. These results are important for the realization of CMOS-compatible efficient light emitters at telecom wavelengths.

  5. Audit Report: ER-B-98-02 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    2 Audit Report: ER-B-98-02 October 24, 1997 Audit of Environmental Monitoring and Health Physics Laboratories at the Savannah River Site The Environmental Monitoring and Health Physics Laboratories at the Department of Energy's (Department) Savannah River Site are over 40 years old and are approaching the end of their useful lives. The managing and operating contractor, Westinghouse Savannah River Company (Westinghouse), and the Savannah River Operations Office (Operations Office) proposed to

  6. Audit Report: ER-B-98-09 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    9 Audit Report: ER-B-98-09 July 15, 1998 Disposal of Tritium Residues at the Los Alamos National Laboratory In 1991 the Secretary of Energy directed the Assistant Secretary for Environment, Safety and Health to form a Task Group to review tritium facility management practices and identify measures to improve tritium operations. The Task Group issued a report in October 1991 stating that there was an overall lack of attention to managing tritium residues throughout the Department of Energy

  7. Audit Report: ER-B-00-03 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    3 Audit Report: ER-B-00-03 June 19, 2000 Waste Characterization at Oak Ridge Waste characterization is a series of steps performed to determine the weight, volume, and physical characteristics of radioactive waste. The Department of Energy (Department) uses data obtained from waste characterization to evaluate treatment and disposal options for the waste. The characterization process begins when the generator of the waste prepares a general description of the waste produced. The extent of work

  8. Microsoft Word - DOE-ER-0670T_6.09_Final.doc

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

    ER-0670T UC-402 Science Plan for the Atmospheric Radiation Measurement Program (ARM) February 1996 United States Department of Energy Office of Energy Research Office of Health and Environmental Research Environmental Sciences Division Washington, DC 20585 ARM Science Plan iii Executive Summary The purpose of this Atmospheric Radiation Measurement (ARM) Science Plan is to articulate the scientific issues driving the ARM Program, and to relate them to DOE's programmatic objectives for ARM, based

  9. Audit Report: ER-B-98-06 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    8-06 Audit Report: ER-B-98-06 April 1, 1998 Fluor Daniel Fernald's Use of Temporary Service Subcontractors The Department of Energy (Department) and Fluor Daniel Fernald (Fluor Daniel) implemented two work force restructurings at the Fernald Environmental Management Project between Fiscal Years (FY) 1994 and 1996. During the restructurings, the Department's cost for temporary service subcontracts increased from $2.8 million to $9.8 million annually. The objective of this audit was to determine

  10. Audit Report: ER-B-99-03 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    3 Audit Report: ER-B-99-03 January 25, 1999 Westinghouse Savannah River Company's Health Benefit Plan Westinghouse Savannah River Company (Westinghouse) manages and operates the Savannah River Site, located in Aiken, South Carolina, for the U.S. Department of Energy (Department). Westinghouse was self-insured for health benefits and contracted with Aetna Insurance to administer the plan (service payments to providers) from Calendar Year (CY) 1989 through 1996. Westinghouse's administrative

  11. Audit Report: ER-B-99-05 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    5 Audit Report: ER-B-99-05 April 8, 1999 Westinghouse Savannah River Company's Withdrawal of Fees As the operator of the Department's Savannah River Site, Westinghouse Savannah River Company (Westinghouse) receives three types of fees: (1) award fees commensurate with the overall performance rating, (2) Performance Based Incentive (PBI) fees for achieving measurable goals or defined tasks as specified in annual operating plans, and (3) Cost Reduction Incentive Program (CRIP) fees for making

  12. Audit Report: ER-B-99-08 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    8 Audit Report: ER-B-99-08 May 12, 1999 Health Physics Technician Subcontracts at Brookhaven National Laboratory To supplement its health physics staff, Brookhaven National Laboratory (Brookhaven) subcontracted with a support service business (the subcontractor) to obtain the services of health physics technicians. During the performance of these subcontracts, certain issues arose concerning per diem payments to the subcontractor for local technicians. The objective of this audit was to

  13. Audit Report: ER-L-02-01 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    L-02-01 Audit Report: ER-L-02-01 February 7, 2002 The Department of Energy's Strategy for Disposal of Plutonium In September 2000, the United States and the Russian Federation entered into an agreement stipulating that each country will irreversibly transform 34 metric tons of weapons-grade plutonium into forms which could not be used for weapons purposes. To meet the United States' commitment, the Department of Energy planned activities at its Savannah River Site; specifically, to immobilize

  14. Cw laser action of Er/sup 3 +/ in double sensitized fluoroaluminate glass at room temperature

    SciTech Connect (OSTI)

    Heumann, E.; Ledig, M.; Ehrt, D.; Seeber, W.; Duczynski, E.W.; Heide, H.v.; Huber, G.

    1988-01-25

    cw lasing at 1.6 ..mu..m was obtained for the first time in Cr, Yb, Er:fluoroaluminate glass. Double step pumping via Cr/sup 3 +/ and Yb/sup 3 +/ with a krypton laser yields a threshold pump power of 80 mW. Efficient lasing can be expected using glass samples of optimized dopant concentration and improved optical quality.

  15. Water-assisted pulsed Er:YAG laser interaction with silicon

    SciTech Connect (OSTI)

    Kim, Jaehun; Ki, Hyungson

    2015-07-07

    Silicon is virtually transparent to the Er:YAG laser with a wavelength of 2.94 μm. In this study, we report that moderately doped silicon (1–10 Ω cm) can be processed by a pulsed Er:YAG laser with a pulse duration of 350 μs and a peak laser intensity of 1.7 × 10{sup 5} W/cm{sup 2} by applying a thin water layer on top of silicon as a light absorbing medium. In this way, water is heated first by strongly absorbing the laser energy and then heats up the silicon wafer indirectly. As the silicon temperature rises, the free carrier concentration and therefore the absorption coefficient of silicon will increase significantly, which may enable the silicon to get directly processed by the Er:YAG laser when the water is vaporized completely. We also believe that the change in surface morphology after melting could contribute to the increase in the laser beam absorptance. It was observed that 525 nm-thick p-type wafer specimens were fully penetrated after 15 laser pulses were irradiated. Bright yellow flames were observed during the process, which indicates that the silicon surface reached the melting point.

  16. Synthesis and characterization of hollow mesoporous BaFe12O19 spheres

    SciTech Connect (OSTI)

    Xu, X; Park, J; Hong, YK; Lane, AM

    2015-02-01

    A facile method is reported to synthesize hollow mesoporous BaFe12O19 spheres using a template-free chemical etching process. Hollow BaFe12O19 spheres were synthesized by conventional spray pyrolysis. The mesoporous structure is achieved by alkaline ethylene glycol etching at 185 degrees C, with the porosity controlled by the heating time. The hollow porous structure is confirmed by SEM, TEM, and FIB-FESEM characterization. The crystal structure and magnetic properties are not significantly affected after the chemical etching process. The formation mechanism of the porous structure is explained by grain boundary etching. (C) 2014 Elsevier Inc. All rights reserved.

  17. Crystal structures and phase transitions in Ba{sub 2}HoTaO{sub 6}

    SciTech Connect (OSTI)

    Kennedy, Brendan J. Saines, Paul J.; Kubota, Yoshiki; Minakata, Chiharu; Hano, Hiroko; Kato, Kenichi; Takata, Masaki

    2007-11-06

    The structure of the cation-ordered double perovskite Ba{sub 2}HoTaO{sub 6} was examined using synchrotron X-ray powder diffraction at fine temperature intervals over the range of 90-300 K. Ba{sub 2}HoTaO{sub 6} has a cubic structure in space group Fm3-barm at room temperature. A proper ferroelastic phase transition to I4/m tetragonal symmetry occurs near approximately 260 K. Analysis of the spontaneous tetragonal strain versus temperature indicated that the phase transition is second order in nature.

  18. Electron-hole asymmetry, Dirac fermions, and quantum magnetoresistance in BaMnBi2

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Li, Lijun; Wang, Kefeng; Graf, D.; Wang, Limin; Wang, Aifeng; Petrovic, C.

    2016-03-28

    Here, we report two-dimensional quantum transport and Dirac fermions in BaMnBi2 single crystals. BaMnBi2 is a layered bad metal with highly anisotropic conductivity and magnetic order below 290 K. Magnetotransport properties, nonzero Berry phase, small cyclotron mass, and the first-principles band structure calculations indicate the presence of Dirac fermions in Bi square nets. Quantum oscillations in the Hall channel suggest the presence of both electron and hole pockets, whereas Dirac and parabolic states coexist at the Fermi level.

  19. Spin-driven multiferroics in BaYFeO{sub 4}

    SciTech Connect (OSTI)

    Cong, Jun-Zhuang; Shen, Shi-Peng; Chai, Yi-Sheng; Yan, Li-Qin; Shang, Da-Shan; Wang, Shou-Guo; Sun, Young

    2015-05-07

    We report on the spin-driven multiferroic property and magnetoelectric effect in the lately synthesized compound BaYFeO{sub 4}. Due to its peculiar crystal structure, the system exhibits complex magnetic phases with multiple transitions. The dielectric and pyroelectric measurements evidence a spin-driven multiferroic state raised by the cycloidal spin structure below T{sub 1} = 36 K. Strong magnetoelectric effect has also been observed in the multiferroic state. The origin of noncollinear cycloidal spin structure in BaYFeO{sub 4} is believed to arise from the interactions between low-dimensional magnetic columns.

  20. The luminescence of BaF{sub 2} nanoparticles upon high-energy excitation

    SciTech Connect (OSTI)

    Vistovskyy, V. V. Zhyshkovych, A. V.; Halyatkin, O. O.; Voloshinovskii, A. S.; Mitina, N. E.; Zaichenko, A. S.; Rodnyi, P. A.; Vasil'ev, A. N.; Gektin, A. V.

    2014-08-07

    The dependence of X-ray excited luminescence intensity on BaF{sub 2} nanoparticle size was studied. A sharp decrease of self-trapped exciton luminescence intensity was observed when the nanoparticle size is less than 80?nm. The main mechanism of the luminescence quenching is caused by the escape of electrons from the nanoparticles. Escape of electrons from nanoparticles is confirmed by the considerable increase of luminescence intensity of the polystyrene scintillator with embedded BaF{sub 2} nanoparticles comparing with pure polystyrene scintillator.

  1. Fermi surfaces and phase stability of Ba(Fe1 xMx)2As2 (M = Co...

    Office of Scientific and Technical Information (OSTI)

    Fermi surfaces and phase stability of Ba(Fe1 xMx)2As2 (M Co,Ni,Cu,Zn) Citation Details In-Document Search Title: Fermi surfaces and phase stability of Ba(Fe1 xMx)2As2 (M ...

  2. Fermi surfaces and Phase Stability of Ba(Fe1-xMx))2As2 (M=Co...

    Office of Scientific and Technical Information (OSTI)

    Fermi surfaces and Phase Stability of Ba(Fe1-xMx))2As2 (MCo, Ni, Cu, Zn) Citation Details In-Document Search Title: Fermi surfaces and Phase Stability of Ba(Fe1-xMx))2As2 (MCo,...

  3. High-pressure densified solid solutions of alkaline earth hexaborides (Ca/Sr, Ca/Ba, Sr/Ba) and their high-temperature thermoelectric properties

    SciTech Connect (OSTI)

    Gürsoy, M.; Takeda, M.; Albert, B.

    2015-01-15

    Solid solutions of alkaline earth hexaborides were synthesized and densified by spark plasma sintering at 100 MPa. The high-temperature thermoelectric properties (Seebeck coefficients, electrical and thermal diffusivities, heat capacities) were measured between room temperature and 1073 K. CaB{sub 6}, SrB{sub 6}, BaB{sub 6} and the ternary hexaborides Ca{sub x}Sr{sub 1−x}B{sub 6}, Ca{sub x}Ba{sub 1−x}B{sub 6}, Sr{sub x}Ba{sub 1−x}B{sub 6} (x = 0.25, 0.5, 0.75) are n-type conducting compounds over the whole compositional and thermal ranges. The values of the figure of merit ZT for CaB{sub 6} (ca. 0.3 at 1073 K) were found to be significantly increased compared to earlier investigations which is attributed to the densification process. - Highlights: • Solid solutions of alkaline earth hexaborides were synthesized. • High-temperature thermoelectric properties of mixed calcium borides are excellent. • Spark plasma source densification results in high ZT values. • Borides are rare-earth free and refractory materials.

  4. Analysis of Well ER-EC-6 Testing, Western Pahute Mesa - Oasis Valley FY 2000 Testing Program

    SciTech Connect (OSTI)

    2002-09-30

    This report documents the analysis of the data collected for Well ER-EC-6 during the Western Pahute Mesa-Oasis Valley (WPM-OV) well development and testing program that was conducted during fiscal year (FY) 2000. The data collection for that program is documented in Appendix A, Western Pahute Mesa-Oasis Valley, Well ER-EC-6 Data Report for Development and Hydraulic Testing.

  5. Analysis of Well ER-EC-2a Testing, Western Pahute Mesa-Oasis Valley FY 2000 Testing Program

    SciTech Connect (OSTI)

    2002-09-30

    This report documents the analysis of the data collected for Well ER-EC-2a during the Western Pahute Mesa - Oasis Valley (WPM-OV) well development and testing program that was conducted during fiscal year (FY) 2000. The data collection for that program is documented in Appendix A, Western Pahute Mesa - Oasis Valley, Well ER-EC-2a Data Report for Development and Hydraulic Testing.

  6. Analysis of well ER-18-2 testing, Western Pahute Mesa - Oasis Valley FY 2000 testing program

    SciTech Connect (OSTI)

    2002-09-30

    This report documents the analysis of the data collected for Well ER-18-2 during the Western Pahute Mesa - Oasis Valley (WPM-OV) well development and testing program that was conducted during fiscal year (FY) 2000. The data collection for that program is documented in Appendix A, Western Pahute Mesa - Oasis Valley, Well ER-18-2 Data Report for Development and Hydraulic Testing.

  7. Structural basis for a hand-like site in the calcium sensor CatchER with fast kinetics

    SciTech Connect (OSTI)

    Zhang, Ying; Reddish, Florence; Tang, Shen; Zhuo, You; Wang, Yuan-Fang; Yang, Jenny J.; Weber, Irene T.

    2013-12-01

    High-resolution crystal structures of the designed calcium sensor CatchER revealed snapshots of calcium and gadolinium ions binding within the designed site in agreement with its fast kinetics. Calcium ions, which are important signaling molecules, can be detected in the endoplasmic reticulum by an engineered mutant of green fluorescent protein (GFP) designated CatchER with a fast off-rate. High resolution (1.78–1.20 Å) crystal structures were analyzed for CatchER in the apo form and in complexes with calcium or gadolinium to probe the binding site for metal ions. While CatchER exhibits a 1:1 binding stoichiometry in solution, two positions were observed for each of the metal ions bound within the hand-like site formed by the carboxylate side chains of the mutated residues S147E, S202D, Q204E, F223E and T225E that may be responsible for its fast kinetic properties. Comparison of the structures of CatchER, wild-type GFP and enhanced GFP confirmed that different conformations of Thr203 and Glu222 are associated with the two forms of Tyr66 of the chromophore which are responsible for the absorbance wavelengths of the different proteins. Calcium binding to CatchER may shift the equilibrium for conformational population of the Glu222 side chain and lead to further changes in its optical properties.

  8. Synthesis and Structure Determination of Ferromagnetic Semiconductors LaAMnSnO6 (A = Sr Ba)

    SciTech Connect (OSTI)

    T Yang; T Perkisas; J Hadermann; M Croft; A Ignatov; M Greenblatt

    2011-12-31

    LaAMnSnO{sub 6} (A = Sr, Ba) have been synthesized by high temperature solid-state reactions under dynamic 1% H{sub 2}/Ar flow. Rietveld refinements on room temperature powder X-ray diffraction data indicate that LaSrMnSnO{sub 6} crystallizes in the GdFeO{sub 3}-structure, with space group Pnma and, combined with transmission electron microscopy, LaBaMnSnO{sub 6} in Imma. Both space groups are common in disordered double-perovskites. The Mn{sup 3+} and Sn{sup 4+} ions whose valence states were confirmed by X-ray absorption spectroscopy, are completely disordered over the B-sites and the BO{sub 6} octahedra are slightly distorted. LaAMnSnO{sub 6} are ferromagnetic semiconductors with a T{sub C} = 83 K for the Sr- and 66 K for the Ba-compound. The title compounds, together with the previously reported LaCaMnSnO{sub 6} provide an interesting example of progression from Pnma to Imma as the tolerance factor increases. An analysis of the relationship between space group and tolerance factor for the series LaAMnMO{sub 6} (A = Ca, Sr, Ba; M = Sn, Ru) provides a better understanding of the symmetry determination for double perovskites.

  9. Atomic and electronic structure of the ferroelectric BaTiO{sub 3}/Ge(001) interface

    SciTech Connect (OSTI)

    Fredrickson, Kurt D.; Ponath, Patrick; Posadas, Agham B.; Demkov, Alexander A.; McCartney, Martha R.; Smith, David J.; Aoki, Toshihiro

    2014-06-16

    In this study, we demonstrate the epitaxial growth of BaTiO{sub 3} on Ge(001) by molecular beam epitaxy using a thin Zintl template buffer layer. A combination of density functional theory, atomic-resolution electron microscopy and in situ photoemission spectroscopy is used to investigate the electronic properties and atomic structure of the BaTiO{sub 3}/Ge interface. Aberration-corrected scanning transmission electron micrographs reveal that the Ge(001) 2??1 surface reconstruction remains intact during the subsequent BaTiO{sub 3} growth, thereby enabling a choice to be made between several theoretically predicted interface structures. The measured valence band offset of 2.7?eV matches well with the theoretical value of 2.5?eV based on the model structure for an in-plane-polarized interface. The agreement between the calculated and measured band offsets, which are highly sensitive to the detailed atomic arrangement, indicates that the most likely BaTiO{sub 3}/Ge(001) interface structure has been identified.

  10. Audit Report: ER-B-99-01 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    9-01 Audit Report: ER-B-99-01 December 21, 1998 Decontamination and Decommissioning at the East Tennessee Technology Park The East Tennessee Technology Park (ETTP) contains about 400 buildings with approximately 14.4 million square feet of space. Almost 90 percent of the space is comprised of buildings that are currently undergoing or are planned for decontamination and decommissioning (D&D). Departmental policy requires that D&D projects be prioritized based on employee and public

  11. Audit Report: ER-B-99-04 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    4 Audit Report: ER-B-99-04 March 15, 1999 Credit Card Usage at the Ohio Field Office and the Fernald and Miamisburg Environmental Management Projects The Department of Energy (Department) obtained the services of Rocky Mountain BankCard System, through the use of a General Services Administration contract, as a means for the Department and its contractors to make small purchases. The Ohio Field Office (Field Office) uses the credit card system and oversees usage by the Fernald and Miamisburg

  12. Progress Report- DE-FG02-03ER46078-University of Houston

    Office of Scientific and Technical Information (OSTI)

    Final Report- DE-FG02-08ER46486-University of Houston Neutron Compton Scattering as a Probe of Hydrogen Bonded (and other) Systems George Reiter December 22, 2010 Period: Feb 1, 2010-Jan 31, 2011 Summary of work: 3-D Measurements of Born-Oppenheimer Potential Measurements of the momentum distribution of Rb3H(SO4)2 at 120K and 170K have been analyzed, and a paper submitted to PRB. It is now in the review process. The import of the paper is that the effective Born Oppenheimer potential for the

  13. US DEPARTMENT OF ENERGY EERE PROJECT MANAGEMENT CENTER NEPA DEI'ER1IllNATION

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    EERE PROJECT MANAGEMENT CENTER NEPA DEI'ER1IllNATION Page I of3 RECIPIENT:Verdant Power, Inc. STATE: NY PROJECT TITLE : Advancement of the Kinetic Hydropower System (KHPS) to DOE TRL 7/8 Funding Opportunity Announcement Number DE-FOA-OOOO293 Procurement Instrument Number NEPA Control Number CID Number DE-EEOOO5929 GF0-0005929-OO1 EE5929 Based on my review of the information concerning the proposed action, as NEPA Compliance Officer (authorized under DOE Order 451.1A), I have made the following

  14. Controlled synthesis and optical properties of BaFBr:Eu{sup 2+} crystals via ethanol/water solutions

    SciTech Connect (OSTI)

    Liang, Qinghua; Graduate University of Chinese Academy of Sciences, Beijing 10039 ; Li, Zhi; Ma, Wangjing; Shi, Yao; Yang, Xinmin

    2012-09-15

    Graphical abstract: A facile and cost-effective approach for the controlled synthesis of BaFBr:Eu{sup 2+} crystals is introduced. The structures and morphologies of the obtained products are affected by the amount of water and ethanol in the solvent mixtures. Highlights: ► Precipitation route for preparing BaFBr nano and micro crystals in water/ethanol solvent mixtures. ► Controlled growth of BaFBr nano crystals by tuning the volume ratio of Ethanol/water. ► Luminescence properties after annealing at 200 °C are investigated. ► Short lifetimes of photoluminescence and photostimulated luminescence in BaFBr:Eu{sup 2+} nano crystals are presented. ► Shortened lifetimes in BaFBr:Eu{sup 2+} nano crystals demonstrate that they are promising materials for use in X-ray imaging systems. -- Abstract: BaFBr:Eu{sup 2+} crystals with different structures were successfully fabricated via a simple precipitation method using ethanol/water mixtures as solvents. The amount of ethanol in the solvent mixtures played a significant role in the formation of final products, enabling the well-controlled growth of the BaFBr crystals. A possible formation mechanism was proposed based on the results of controlled experiments. The phases and morphologies of the resulting samples were systematically investigated by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), selected area electron diffraction (SAED) and elementary analysis. The optical properties of the annealed BaFBr:Eu{sup 2+} nano-cuboids were investigated using photoluminescence (PL), photo-stimulated luminescence spectroscopy (PSL) and kinetic decays. Faster decay behaviors demonstrate that these BaFBr:Eu{sup 2+} phosphors are promising materials for applications in optical storage fields. Furthermore, it is envisaged that this environmentally benign method can be extended to prepare other fluoride halides.

  15. Synthesis, structural and magnetic characterisation of the fully fluorinated compound 6H-BaFeO{sub 2}F

    SciTech Connect (OSTI)

    Clemens, Oliver; Wright, Adrian J.; Berry, Frank J.; Smith, Ronald I.; Slater, Peter R.

    2013-02-15

    The compound 6H-BaFeO{sub 2}F (P6{sub 3}/mmc) was synthesised by the low temperature fluorination of 6H-BaFeO{sub 3-d} using polyvinylidenedifluoride (PVDF) as a fluorination agent. Structural characterisation by XRD and NPD suggests that the local positions of the oxygen and fluorine atoms vary with no evidence for ordering on the anion sites. This compound shows antiferromagnetic ordering at room temperature with antiparallel alignment of the magnetic moments along the c-axis. The use of PVDF also allows the possibility of tuning the fluorine content in materials of composition 6H-BaFeO{sub 3-d}F{sub y} to any value of 0BaFeO{sub 2}F. Highlights: Black-Right-Pointing-Pointer The crystal structure of the hexagonal perovskite phase 6H-BaFeO{sub 2}F. Black-Right-Pointing-Pointer H-BaFeO{sub 2}F and 6H-BaFeO{sub 3-d}F{sub y} were prepared via low temperature fluorination using PVDF. Black-Right-Pointing-Pointer A structural investigation of the compounds BaFeO{sub 2}F is presented in detail. Black-Right-Pointing-Pointer This analysis suggests differences for the local coordination of O{sup 2-} and F{sup -} anions. Black-Right-Pointing-Pointer H-BaFeO{sub 2}F shows antiferromagnetic ordering at 300 K. Black-Right-Pointing-Pointer The magnetic moments align parallel to the a-axis.

  16. Synthesis, structural and magnetic characterisation of the fluorinated compound 15R-BaFeO{sub 2}F

    SciTech Connect (OSTI)

    Clemens, Oliver; Berry, Frank J.; Bauer, Jessica; Wright, Adrian J.; Knight, Kevin S.; Slater, Peter R.

    2013-07-15

    The compounds 15R-BaFeO{sub 2}F and 15R-BaFeO{sub 2.27}F{sub 0.5} have been synthesised by the low temperature fluorination of 15R-BaFeO{sub 3−d}F{sub 0.2} using polyvinylidenedifluoride (PVDF) as a fluorination agent. The materials have been structurally characterised by Rietveld analysis of the X-ray- and HRPD-powder neutron diffraction data. A detailed analysis of bond valence sums suggests that the oxide and fluoride ions order on the different anion sites. A reinvestigation of our recently published structure (Clemens et al., 2013) [34] of 6H-BaFeO{sub 2}F is also reported and incorporation of fluoride in h-type layers is also confirmed in this compound. The magnetic moments for 15R-BaFeO{sub 2}F and 15R-BaFeO{sub 2.25}F{sub 0.5} align in the a/b-plane with antiferromagnetic alignment of the moments between adjacent layers, and are flipped by 90° as compared to the precursor compound. 15R-BaFeO{sub 2}F exhibits very robust antiferromagnetism with a Néel temperature between 300 and 400 °C. - Graphical abstract: The crystal and magnetic structure of the perovskite phase 15R-BaFeO{sub 2}F. - Highlights: • 15R-BaFeO{sub 2}F and 15R-BaFeO{sub 2.27}F{sub 0.5}were prepared via low temperature fluorination using PVDF. • A structural investigation of the compounds BaFeO{sub 2}F is presented in detail. • This analysis suggests ordering of O{sup 2−} and F{sup −} anions between different layers. • 15R-BaFeO{sub 2}F shows antiferromagnetic ordering at 300 K with T{sub N} ∼300–400 °C. • The magnetic moments align in the a/b-plane.

  17. Electrical Properties of Er-doped In0.53Ga0.47As

    SciTech Connect (OSTI)

    Burke, Peter G.; Lu, Hong; Rudawski, Nicholas G.; Stemmer, Susanne; Gossard, Arthur C.; Bahk, Je-Hyeong; Bowers, John E.

    2011-03-03

    The electrical properties of In0.53Ga0.47As As thin films Er-doped to concentrations of 1.51017 7.21020 cm-3 grown by molecular beam epitaxy at 490 C on (001) InP substrates were studied. Electrical conductivity, carrier density, and carrier mobility as a function of Er doping were measured by Hall effect at temperatures of 20750 K. Additionally, high-angle annular dark-field scanning transmission electron microscopy and infrared absorption spectroscopy confirmed the presence of epitaxially embedded ErAs nanoparticles at Er concentrations ?81019 cm-3. The observed electrical properties are discussed in terms of the dependence of ErAs nanoparticle formation with Er doping.

  18. Absence of exchange interaction between localized magnetic moments and conduction-electrons in diluted Er{sup 3+} gold-nanoparticles

    SciTech Connect (OSTI)

    Lesseux, G. G. Urbano, R. R.; Iwamoto, W.; Garca-Flores, A. F.; Rettori, C.

    2014-05-07

    The Electron Spin Resonance (ESR) of diluted Er{sup 3+} magnetic ions in Au nanoparticles (NPs) is reported. The NPs were synthesized by reducing chloro triphenyl-phosphine gold(I) and erbium(III) trifluoroacetate. The Er{sup 3+} g-value along with the observed hyperfine splitting indicate that the Er{sup 3+} impurities are in a local cubic symmetry. Furthermore, the Er{sup 3+} ESR spectra show that the exchange interaction between the 4f and the conduction electrons (ce) is absent or negligible in Au{sub 1x}Er{sub x} NPs, in contrast to the ESR results in bulk Au{sub 1x}Er{sub x}. Therefore, the nature of this interaction needs to be reexamined at the nano scale range.

  19. Er{sup 3+}/Yb{sup 3+}co-doped bismuth molybdate nanosheets upconversion photocatalyst with enhanced photocatalytic activity

    SciTech Connect (OSTI)

    Adhikari, Rajesh; Gyawali, Gobinda; Cho, Sung Hun; Narro-Garca, R.; Sekino, Tohru; Lee, Soo Wohn

    2014-01-15

    In this paper, we report the microwave hydrothermal synthesis of Er{sup 3+}/Yb{sup 3+} co-doped Bi{sub 2}MoO{sub 6} upconversion photocatalyst. Crystal structure, morphology, elemental composition, optical properties and BET surface area were analyzed in detail. Infrared to visible upconversion luminescence at 532 nm and 546 nm of the co-doped samples was investigated under excitation at 980 nm. The results revealed that the co-doping of Er{sup 3+}/Yb{sup 3+} into Bi{sub 2}MoO{sub 6} exhibited enhanced photocatalytic activity for the decomposition of rhodamine B under simulated solar light irradiation. Enhanced photocatalytic activity can be attributed to the energy transfer between Er{sup 3+}/Yb{sup 3+} and Bi{sub 2}MoO{sub 6} via infrared to visible upconversion from Er{sup 3+}/Yb{sup 3+} ion and higher surface area of the Bi{sub 2}MoO{sub 6} nanosheets. Therefore, this synthetic approach may exhibit a better alternative to fabricate upconversion photocatalyst for integral solar light absorption. - Graphical abstract: Schematic illustration of the upconversion photocatalysis. Display Omitted - Highlights: Er{sup 3+}/Yb{sup 3+} co-doped Bi{sub 2}MoO{sub 6} upconversion photocatalyst is successfully synthesized. We obtained the nanosheets having high surface area. Upconversion of IR to visible light was confirmed. Upconversion phenomena can be utilized for effective photocatalysis.

  20. Effect of nonmagnetic impurities on the residual electron-spin-resonance linewidth of Er:Ag dilute alloys

    SciTech Connect (OSTI)

    Dahlberg, E.D.; Souletie, J.; Dodds, S.A.; Chock, E.P.; Orbach, R.L. )

    1990-06-01

    We have undertaken a systematic investigation of the effect of nonmagnetic impurities on the residual ({ital T}{r arrow}0 K) electron-spin-resonance linewidth of erbium in dilute (200 parts per million atomic (ppm)) Er:Ag alloys. The nonmagnetic impurities used were In, Sn, Sb, Y, and Lu in the concentration range of 500--4600 ppm. The linewidth broadening caused by these impurities was found to be 0.2{plus minus}0.11, 0.49{plus minus}0.1, 0.51{plus minus}0.11, 1.4{plus minus}0.18, and 1.37{plus minus}0.32 G/1000 ppm atomic frequency (GHz) for In, Sn, Sb, Y, and Lu, respectively. The most reasonable source of the Er line broadening is the mixing of the crystal-field levels of the Er by the Kohn-Vosko oscillations in the charge density. The broadening of the Er resonance line due to In, Sn, and Sb doping is consistent with the expected form of the oscillations. Also, Y and Lu are equivalent in the broadening of the Er line, as expected. However, the scaling of the Y and Lu broadening compared to that due to the In, Sn, and Sb is not consistent. The reasons for this are not understood.

  1. The role of Nb in intensity increase of Er ion upconversion luminescence in zirconia

    SciTech Connect (OSTI)

    Smits, K. Sarakovskis, A.; Grigorjeva, L.; Millers, D.; Grabis, J.

    2014-06-07

    It is found that Nb co-doping increases the luminescence and upconversion luminescence intensity in rare earth doped zirconia. Er and Yb-doped nanocrystalline samples with or without Nb co-doping were prepared by sol-gel method and thermally annealed to check for the impact of phase transition on luminescence properties. Phase composition and grain sizes were examined by X-ray diffraction; the morphology was checked by scanning- and high-resolution transmission electron microscopes. Both steady-state and time-resolved luminescence were studied. Comparison of samples with different oxygen vacancy concentrations and different Nb concentrations confirmed the known assumption that oxygen vacancies are the main agents for tetragonal or cubic phase stabilization. The oxygen vacancies quench the upconversion luminescence; however, they also prevent agglomeration of rare-earth ions and/or displacement of rare-earth ions to grain surfaces. It is found that co-doping with Nb ions significantly (>20 times) increases upconversion luminescence intensity. Hence, ZrO{sub 2}:Er:Yb:Nb nanocrystals may show promise for upconversion applications.

  2. Development of bubble microstructure in ErT2 films during aging

    SciTech Connect (OSTI)

    Bond, Gillian; Snow, Clark

    2010-01-01

    Helium bubbles form in metal tritide films as tritium decays into 3He, influencing mechanical properties and long-term film stability. The bubble nucleation and growth mechanisms comprise an active research area, but there has been only one previous systematic experimental study of helium bubble growth in metal tritides, on zirconium tritides. There have been no such studies on tritides such as ErT2 that form plate-like bubbles and lack a secondary bubble population on a network of line dislocations, and yet such a study is needed to inform the modeling of helium-bubble microstructure development in a broader range of metal tritides. Transmission electron microscopy (TEM) has been used to study the growth and evolution of helium bubbles in ErT2 films over a four-year period. The results have been used to test the present models of helium bubble nucleation and growth in metal tritides, particularly those forming plate-like bubbles. The results support the models of Trinkaus and Cowgill. The observations of non-uniform bubble thicknesses and the pattern of grain-boundary bubble formation, however, indicate that these models could be strengthened by closer attention to details of interfacial energy. It is strongly recommended that efforts be made (either experimentally or by calculation) to determine anisotropy of tritide/helium interfacial energy, both for clean, stoichiometric interfaces, and also allowing for such factors as non-stoichiometry and segregation.

  3. 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; Rogl, Peter; Bednar, Ingeborg; Bauer, Ernst

    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.

  4. Final Technical Report DE-FG02-08ER41540. Establishing the Transport Properties of QCD With Heavy Ion Reactions

    SciTech Connect (OSTI)

    Teaney, Derek

    2015-03-17

    We review the results of the DE-FG02-08ER41540, "Establishing the transport properties of QCD with heavy ion reactions"

  5. Optical properties of Pr-doped BaY{sub 2}F{sub 8}

    SciTech Connect (OSTI)

    Andrade, Adriano B. Mello, Ana C. S. de; Valerio, Mrio E. G.; Rezende, Marcos V. dos S.; Baldochi, Sonia L.

    2014-08-07

    Crystalline samples of Pr-doped BaY{sub 2}F{sub 8} (BaYF) were prepared by zone melting technique. The pure phase obtained was identified by X-ray diffraction measurement. Optical absorption result was evaluated and it showed that the formation of the absorption bands can be connected to color centers generated by radiation in the matrix. Radioluminescence emission measurements after excitation by X-ray showed that the material exhibited components responsible for long lasting phosphorescence. Short decay times were also evaluated, the measurements showed a fast component around 70?ns associated to the 4f{sup 1}5d{sup 1} ? 4f{sup 2} transition of the Pr{sup 3+} ion. The Thermoluminescence (TL) results indicate the presence of two trapping centers.

  6. Single crystal growth and characterization of the large-unit-cell compound Cu13Ba

    SciTech Connect (OSTI)

    Jesche, Anton; Budko, Serguei L.; Canfield, Paul C.

    2013-10-31

    Single crystals of Cu13Ba were successfully grown out of BaCu self flux. Temperature dependent magnetization, M (T ), electrical resistivity, ?(T)?(T), and specific heat, Cp(T)Cp(T), data are reported. Isothermal magnetization measurements, M(H)M(H), show clear de Haas-van Alphen oscillations at T = 2 K for applied fields as low as View the MathML source?0H=1T. An anomalous behavior of the magnetic susceptibility is observed up to T ? 50 K reflecting the effect of de Haas-van Alphen oscillations at fairly high temperatures. The field- and temperature-dependencies of the magnetization indicate the presence of diluted magnetic impurities with a concentration of the order of 0.01 at.%. Accordingly, the minimum and lower temperature rise observed in the electrical resistivity at and below T = 15 K is attributed to the Kondo-impurity effect.

  7. Melt-processing of Y-Ba-Cu-O superconductors for improved levitation

    SciTech Connect (OSTI)

    Balachandran, U.; Zhong, W.; Emerson, J.E.; McDaniel, R.L.

    1994-04-01

    Melt processed bulk YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} (YBCO) superconductors are of considerable interest in the application of low-friction, superconducting permanent magnet bearings and flywheel-energy-storage devices. The mechanisms of enhanced flux pinning in the melt processed samples has been the subject of many investigations. Fine precipitates of Y{sub 2}BaCuO{sub 5} (211) are considered potential flux-pinning sites by many investigators. Several groups have reported the refinement of 211 precipitates through Pt additions. In this paper, the authors describe the melt processing of YBCO with additives such as 211, Pt, and Ag. Large single domain regions are obtained using small SmBa2Cu3O{sub 7{minus}{delta}} (Sm-123) single crystal seeds. The microstructure and levitation forces are measured and reported here.

  8. 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 1x}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.

  9. K and Mn co-doped BaCd{sub 2}As{sub 2}: A hexagonal structured...

    Office of Scientific and Technical Information (OSTI)

    K and Mn co-doped BaCdsub 2Assub 2: A hexagonal structured bulk diluted magnetic semiconductor with large magnetoresistance Citation Details In-Document Search Title: K and Mn ...

  10. Solution-Derived Bi(ZnTi)O3 - BaTiO3 Thin Films with Bulk-like...

    Office of Scientific and Technical Information (OSTI)

    Title: Solution-Derived Bi(ZnTi)O3 - BaTiO3 Thin Films with Bulk-like Permittivity. Abstract not provided. Authors: Meyer, Kelsey Elizabeth ; Kotula, Paul Gabriel ; Brennecka, ...

  11. Fermi surfaces and phase stability of Ba(Fe1-xMx)2As2 (M = Co...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Fermi surfaces and phase stability of Ba(Fe1-xMx)2As2 (M Co,Ni,Cu,Zn) ... (EFRC); Center for Defect Physics in Structural Materials (CDP) Sponsoring Org: USDOE ...

  12. Recent Results on D0 - Anti-D0 Mixing from BaBar and Belle (Conference...

    Office of Scientific and Technical Information (OSTI)

    Title: Recent Results on D0 - Anti-D0 Mixing from BaBar and Belle Authors: Neri, Nicola ; Pisa U. INFN, Pisa Publication Date: 2013-06-04 OSTI Identifier: 1082815 Report ...

  13. Data:3dfe9516-886e-413a-baed-ae8390939e0b | Open Energy Information

    Open Energy Info (EERE)

    dfe9516-886e-413a-baed-ae8390939e0b No revision has been approved for this page. It is currently under review by our subject matter experts. Jump to: navigation, search Loading......

  14. A Measurement of the Exclusive Branching Fraction for B → π K at BaBar

    SciTech Connect (OSTI)

    Aspinwall, Marie Louise

    2002-02-01

    This thesis presents an exclusive measurement of the branching fraction B for the rare charmless hadronic B decays to πK final states. A sample of 22.57±0.36 million BB pairs was collected with the BaBar detector at the Stanford Linear Accelerator Center's PEP-II B Factory, during the Run 1 data taking period (1999-2000).

  15. Evidence of energy transfer in an aluminosilicate glass codoped with Si nanoaggregates and Er{sup 3+} ions

    SciTech Connect (OSTI)

    Enrichi, F.; Mattei, G.; Sada, C.; Trave, E.; Pacifici, D.; Franzo, G.; Priolo, F.; Iacona, F.; Prassas, M.; Falconieri, M.; Borsella, E.

    2004-10-01

    The enhancement of the Er{sup 3+} ions' photoluminescence (PL) emission at 1.54 {mu}m in a Si and Er coimplanted aluminosilicate glass is investigated in detail. A postimplantation thermal treatment has been performed to recover the damage induced by the implantation process and to promote Si aggregation. It will be shown that 1 h treatment in N{sub 2} atmosphere is not sufficient to induce Si precipitation for temperatures up to 500 deg. C. Nevertheless, the most intense Er{sup 3+} PL emission at 1.54 {mu}m is achieved after a thermal treatment at 400 deg. C. Such emission has been investigated by pumping in and out of resonance, showing a very efficient energy transfer process in the whole excitation wavelength range (360-515 nm). These results suggest that good energy transfer mediators could be small Si aggregates and not only crystalline clusters. For the best performing sample, the effective Er excitation cross section has been measured to be higher than 10{sup -17} cm{sup 2} at 379 and 390 nm and about 2x10{sup -16} cm{sup 2} at 476 nm, that is, several orders of magnitude higher than the Er direct absorption cross section (of the order of 10{sup -21} cm{sup 2} in this glass). Moreover the coefficient of cooperative upconversion has been evaluated to be 2.7x10{sup -18} cm{sup 3} s{sup -1}. The structural and optical properties of this material are discussed and compared to those found for Si and Er codoped silica.

  16. Dielectric investigations in nanostructured tetragonal BaTiO{sub 3} ceramics

    SciTech Connect (OSTI)

    Silveira, L.G.D.; Alves, M.F.S.; Ctica, L.F.; Gotardo, R.A.M.; Nascimento, W.J.; Garcia, D.; Eiras, J.A.; Santos, I.A.

    2013-05-15

    Highlights: ? Nanostructured BaTiO{sub 3} ceramics processed by an innovative protocol. ? Dielectric relaxations related to strains and vacancies. ? Dielectric and ferroelectric properties enhanced by strain. - Abstract: In this paper, structural and dielectric properties of BaTiO{sub 3} ceramics obtained under extreme conditions were investigated. The temperature dependent dielectric investigations revealed that the phase transition temperatures of the BaTiO{sub 3} ceramics were raised as a function of residual strains associated to the nanostructuration, while structural characterizations showed a tetragonal arrangement at room temperature. From the frequency dependence analyses of the imaginary parts of dielectric permittivity, impedance and modulus function, three relaxation processes were identified. Two of them exhibit activation energies of 0.45 and 0.63 eV, and were attributed to single and double-ionization of oxygen vacancies. The whole set of results also indicated that the electrons resulting from the ionization of oxygen vacancies are trapped and do not contribute to the electrical conductivity, while the physical properties of the analyzed samples were enhanced by retaining a strained microstructure.

  17. Hydrodynamic Modeling Analysis for Leque Island and zis a ba Restoration Feasibility Study

    SciTech Connect (OSTI)

    Whiting, Jonathan M.; Khangaonkar, Tarang

    2015-01-31

    Ducks Unlimited, Inc. in collaboration with Washington State Department of Fish and Wildlife (WDFW), and Stillaguamish Tribe of Indians have proposed the restoration of Leque Island and zis a ba (formerly Matterand) sites near the mouth of Old Stillaguamish River Channel in Port Susan Bay, Washington. The Leque Island site, which is owned by WDFW, consists of nearly 253 acres of land south of Highway 532 that is currently behind a perimeter dike. The 90-acres zis a ba site, also shielded by dikes along the shoreline, is located just upstream of Leque Island and is owned by Stillaguamish Tribes. The proposed actions consider the removal or modification of perimeter dikes at both locations to allow estuarine functions to be restored. The overall objective of the proposed projects is to remove the dike barriers to 1) provide connectivity and access between the tidal river channel and the restoration site for use by juvenile migrating salmon and 2) create a self-sustaining tidal marsh habitat. Ducks Unlimited engaged Pacific Northwest National Laboratory (PNNL) to develop a three-dimensional hydrodynamic model of the Port Susan Bay, Skagit Bay, and the interconnecting Leque Island region for use in support of the feasibility assessment for the Leque Island and zis a ba restoration projects. The objective of this modeling-based feasibility assessment is to evaluate the performance of proposed restoration actions in terms of achieving habitat goals while assessing the potential hydraulic and sediment transport impacts to the site and surrounding parcels of land.

  18. Closeout of the award DE-FG02-05ER46223. Trustees of the University of

    Office of Scientific and Technical Information (OSTI)

    Pennsylvania. Project title- "Modular Designed Protein Constructions for Solar Generated H2 From Water (Technical Report) | SciTech Connect Closeout of the award DE-FG02-05ER46223. Trustees of the University of Pennsylvania. Project title- "Modular Designed Protein Constructions for Solar Generated H2 From Water Citation Details In-Document Search Title: Closeout of the award DE-FG02-05ER46223. Trustees of the University of Pennsylvania. Project title- "Modular Designed

  19. Growth and self-assembly of BaTiO{sub 3} nanocubes for resistive switching memory cells

    SciTech Connect (OSTI)

    Chu, Dewei, E-mail: D.Chu@unsw.edu.au [School of Materials Science and Engineering, University of New South Wales, Sydney, 2052 NSW (Australia); Lin, Xi; Younis, Adnan [School of Materials Science and Engineering, University of New South Wales, Sydney, 2052 NSW (Australia); Li, Chang Ming [Chongqing Key Lab for Advanced Materials and Clean Energies of Techonologies Dean, Institute for Clean Energy and Advanced Materials, Southwest University, Chongqing (China); Dang, Feng [Research Center for Materials Back Casting Technology (MBT Center), Nagoya University, Nagoya 464-8603 (Japan); Li, Sean [School of Materials Science and Engineering, University of New South Wales, Sydney, 2052 NSW (Australia)

    2014-06-01

    In this work, the self-assembled BaTiO{sub 3} nanocubes based resistive switching memory capacitors are fabricated with hydrothermal and drop-coating approaches. The device exhibits excellent bipolar resistance switching characteristics with ON/OFF ratio of 5870, better reliability and stability over various polycrystalline BaTiO{sub 3} nanostructures. It is believed that the inter cube junctions is responsible for such a switching behaviour and it can be described by the filament model. The effect of film thickness on switching ratio (ON/OFF) was also investigated in details. - Graphical abstract: This work describes a novel resistive switching memory cell based on self-assembled BaTiO{sub 3} nanocubes. - Highlights: BaTiO{sub 3} nanocubes were prepared by one step facile hydrothermal method. Self-assembled BaTiO{sub 3} nanocubes thin films were obtained by drop-coating approach. The BaTiO{sub 3} nanocubes show excellent resistive switching properties for memory applications.

  20. The new barium zinc mercurides Ba{sub 3}ZnHg{sub 10} and BaZn{sub 0.6}Hg{sub 3.4} - Synthesis, crystal and electronic structure

    SciTech Connect (OSTI)

    Schwarz, Michael; Wendorff, Marco; Roehr, Caroline

    2012-12-15

    The title compounds Ba{sub 3}ZnHg{sub 10} and BaZn{sub 0.6}Hg{sub 3.4} were synthesized from stoichiometric ratios of the elements in Ta crucibles. Their crystal structures, which both represent new structure types, have been determined using single crystal X-ray data. The structure of Ba{sub 3}ZnHg{sub 10} (orthorhombic, oP28, space group Pmmn, a=701.2(3), b=1706.9(8), c=627.3(3)pm, Z=2, R1=0.0657) contains folded 4{sup 4} Hg nets, where the meshes form the bases of flat rectangular pyramids resembling the structure of BaAl{sub 4}. The flat pyramids are connected via Hg-Zn/Hg bonds, leaving large channels at the folds, in which Ba(1) and Hg(2) atoms alternate. Whereas the remaining Hg/Zn atoms form a covalent 3D network of three- to five-bonded atoms with short M-M distances (273-301 pm; CN 9-11), the Hg(2) atoms in the channels adopt a comparatively large coordination number of 12 and increased distances (317-348 pm) to their Zn/Hg neighbours. In the structure of BaZn{sub 0.6}Hg{sub 3.4} (cubic, cI320, space group I4{sup Macron }3d, a=2025.50(7) pm, Z=64, R1=0.0440), with a chemical composition not much different from that of Ba{sub 3}ZnHg{sub 10}, the Zn/Hg atoms of the mixed positions M(1/2) are arranged in an slightly distorted primitive cubic lattice with a 4 Multiplication-Sign 4 Multiplication-Sign 4 subcell relation to the unit cell. The 24 of the originating 64 cubes contain planar cis tetramers Hg(5,6){sub 4} with Hg in a nearly trigonal planar or tetrahedral coordination. In another 24 of the small cubes, two opposing faces are decorated by Hg(3,4){sub 2} dumbbells, two by Ba(2) atoms respectively. The third type of small cubes are centered by Ba(1) atoms only. The complex 3D polyanionic Hg/Zn network thus formed is compared with the Hg partial structure in Rb{sub 3}Hg{sub 20} applying a group-subgroup relation. Despite their different overall structures, the connectivity of the negatively charged Hg atoms, the rather metallic Zn bonding characteristic

  1. Final Technical Report for Grant DE-FG02-04ER54795

    SciTech Connect (OSTI)

    Merlino, Robert L

    2015-10-02

    This is the final technical report for DOE Grant #DE-FG02-04ER54795-Experimental Investigations of Fundamental Processes in Dusty Plasmas. A plasma is an ionized gas, and a dusty plasmas is a plasma that contains, in addition to electrons and ions, micron-sized dust particles. The dust particles acquire and electric charge in the plasma by collecting electrons and ions. The electrons move more rapidly than the ions, so the dust charge is negative. A 1 micron dust particle in a typical low temperature plasma has a charge corresponding to approximately 2000 electrons. Dusty plasmas are naturally found in astrophysical plasmas, planetary rings, technological plasmas, and magnetic fusion plasmas. The goal of this project was to study in the laboratory, the basic physical processes that occur in dusty plasmas. This report provides a summary of the major scientific products and activities of this award.

  2. Completion Report for Model Evaluation Well ER-11-2: Corrective Action Unit 98: Frenchman Flat

    SciTech Connect (OSTI)

    NSTec Underground Test Area and Boreholes Programs and Operations

    2013-01-22

    Model Evaluation Well ER-11-2 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of Nevada Environmental Management Operations at the Nevada National Security Site (formerly known as the Nevada Test Site). The well was drilled in August 2012 as part of a model evaluation program in the Frenchman Flat area of Nye County, Nevada. The primary purpose of the well was to provide detailed geologic, hydrogeologic, chemical, and radionuclide data that can be used to test and build confidence in the applicability of the Frenchman Flat Corrective Action Unit flow and transport models for their intended purpose. In particular, this well was designed to provide data to evaluate the uncertainty in model forecasts of contaminant migration from the upgradient underground nuclear test PIN STRIPE, conducted in borehole U-11b in 1966. Well ER-11-2 will provide information that can be used to refine the Phase II Frenchman Flat hydrostratigraphic framework model if necessary, as well as to support future groundwater flow and transport modeling. The main 31.1-centimeter (cm) hole was drilled to a total depth of 399.6 meters (m). A completion casing string was not set in Well ER-11-2. However, a piezometer string was installed in the 31.1-cm open hole. The piezometer is composed of 7.3-cm stainless-steel tubing hung on 6.0-cm carbon-steel tubing via a crossover sub. The piezometer string was landed at 394.5 m, for monitoring the lower tuff confining unit. Data collected during and shortly after hole construction include composite drill cuttings samples collected every 3.0 m, various geophysical logs, water quality (including tritium and other test-related radionuclides) measurements, and water level measurements. The well penetrated 42.7 m of Quaternary and Tertiary alluvium and 356.9 m of Tertiary volcanic rock. The water-level measured in the piezometer string on September 25, 2012, was 353.8 m below ground surface. No

  3. Ba-filled Ni–Sb–Sn based skutterudites with anomalously high lattice thermal conductivity

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Paschinger, W.; Rogl, Gerda; Grytsiv, A.; Michor, H.; Heinrich, P. R.; Mueller, H.; Puchegger, S.; Klobes, B.; Hermann, Raphael P.; Reinecker, M.; et al

    2016-06-21

    Here, in this study, novel filled skutterudites BayNi4Sb12-xSnx (ymax = 0.93) have been prepared by arc melting followed by annealing at 250, 350 and 450°C up to 30 days in vacuum-sealed quartz vials. Extension of the homogeneity region, solidus temperatures and structural investigations were performed for the skutterudite phase in the ternary Ni–Sn–Sb and in the quaternary Ba–Ni–Sb–Sn systems. Phase equilibria in the Ni–Sn–Sb system at 450°C were established by means of Electron Probe Microanalysis (EPMA) and X-ray Powder Diffraction (XPD). With rather small cages Ni4(Sb,Sn)12, the Ba–Ni–Sn–Sb skutterudite system is perfectly suited to study the influence of filler atomsmore » on the phonon thermal conductivity. Single-phase samples with the composition Ni4Sb8.2Sn3.8, Ba0.42Ni4Sb8.2Sn3.8 and Ba0.92Ni4Sb6.7Sn5.3 were used to measure their physical properties, i.e. temperature dependent electrical resistivity, Seebeck coefficient and thermal conductivity. The resistivity data demonstrate a crossover from metallic to semiconducting behaviour. The corresponding gap width was extracted from the maxima in the Seebeck coefficient data as a function of temperature. Single crystal X-ray structure analyses at 100, 200 and 300 K revealed the thermal expansion coefficients as well as Einstein and Debye temperatures for Ba0.73Ni4Sb8.1Sn3.9 and Ba0.95Ni4Sb6.1Sn5.9. These data were in accordance with the Debye temperatures obtained from the specific heat (4.4 K < T < 140 K) and Mössbauer spectroscopy (10 K < T < 290 K). Rather small atom displacement parameters for the Ba filler atoms indicate a severe reduction in the “rattling behaviour” consistent with the high levels of lattice thermal conductivity. The elastic moduli, collected from Resonant Ultrasonic Spectroscopy ranged from 100 GPa for Ni4Sb8.2Sn3.8 to 116 GPa for Ba0.92Ni4Sb6.7Sn5.3. The thermal expansion coefficients were 11.8 × 10-6 K-1 for Ni4Sb8.2Sn3.8 and 13.8 × 10-6 K-1 for Ba0.92Ni4

  4. Continuous cross-over from ferroelectric to relaxor state and piezoelectric properties of BaTiO{sub 3}-BaZrO{sub 3}-CaTiO{sub 3} single crystals

    SciTech Connect (OSTI)

    Benabdallah, F.; Veber, P. Prakasam, M.; Viraphong, O.; Maglione, M.; Shimamura, K.

    2014-04-14

    Optimal properties like piezoelectricity can be found in polarizable materials for which the structure changes sharply under small composition variations in the vicinity of their morphotropic phase boundary or the triple point in their isobaric temperature-composition phase diagram. In the latter, lead-free (Ba{sub 0.850}Ca{sub 0.150})(Ti{sub 0.900}Zr{sub 0.100})O{sub 3} ceramics exhibit outstanding piezoelectric coefficients. For the first time, we report the growth of piezoelectric lead-free single crystals in the BaTiO{sub 3}-BaZrO{sub 3}-CaTiO{sub 3} pseudo-ternary system. The stoichiometry control in the CaO-BaO-TiO{sub 2}-ZrO{sub 2} solid solution led to single crystals with various compositions ranging from (Ba{sub 0.857}Ca{sub 0.143})(Ti{sub 0.928}Zr{sub 0.072})O{sub 3} to (Ba{sub 0.953}Ca{sub 0.047})(Ti{sub 0.427}Zr{sub 0.573})O{sub 3}. We evidenced a continuous cross-over from a ferroelectric state at high titanium content to a relaxor one on increasing the zirconium content. Such a property tuning is rather seldom observed in lead-free ferroelectrics and confirms what was already reported for ceramics. Single crystal with (Ba{sub 0.838}Ca{sub 0.162})(Ti{sub 0.854}Zr{sub 0.146})O{sub 3} composition, which has been grown and oriented along [001] crystallographic direction, displayed electromechanical coefficients d{sub 31} and k{sub 31} of 93 pC.N{sup −1} and 0.18, respectively, near the room temperature (T = 305 K)

  5. 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; Ekmeki, M. Kaan; Mergen, Ayhan; zen, Gnl

    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 2001700 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.

  6. The structural and magnetic properties of Pr{sub 1−x}Er{sub x}Al{sub 2}

    SciTech Connect (OSTI)

    Pathak, Arjun K.; Gschneidner, K. A.; Pecharsky, V. K.

    2015-05-07

    We report on the effect of Er addition to PrAl{sub 2} on the lattice parameters, magnetic behavior, heat capacity, and magnetocaloric effect by using x-ray diffraction, magnetization, and heat capacity measurements. Unlike Pr{sub 0.6}Er{sub 0.4}Al{sub 2}, other alloys we studied in the pseudobinary (Pr{sub 1−x}Er{sub x})Al{sub 2} system do not exhibit a sharp peak in heat capacity with the application of magnetic field. Both the cubic lattice parameter and the Curie temperature decrease with increasing Er concentration. The nuclear specific heat coefficient decreases from 660 mJ K mol{sup −1} for x = 0.05 to a nearly negligible value for x = 0.95. The magnetic entropy and adiabatic temperature change varies from 2 to 4 J mol{sup −1} K{sup −1} and 2.5 to 5 K at ΔH = 20 kOe for x = 0.05 to 0.95, respectively. These values of the magnetocaloric effect are comparable to those of the other rare-earth dialuminides systems.

  7. The crystal structure of {pi}-ErBO{sub 3}: New single-crystal data for an old problem

    SciTech Connect (OSTI)

    Pitscheider, Almut [Institut fuer Allgemeine, Anorganische und Theoretische Chemie, Leopold-Franzens-Universitaet Innsbruck, Innrain 52a, A-6020 Innsbruck (Austria); Kaindl, Reinhard [Institut fuer Mineralogie und Petrographie, Leopold-Franzens-Universitaet Innsbruck, Innrain 52, A-6020 Innsbruck (Austria); Oeckler, Oliver [Department Chemie, Ludwig-Maximilians-Universitaet Muenchen, Butenandtstrasse 5-13, D-81377 Muenchen (Germany); Huppertz, Hubert, E-mail: Hubert.Huppertz@uibk.ac.a [Institut fuer Allgemeine, Anorganische und Theoretische Chemie, Leopold-Franzens-Universitaet Innsbruck, Innrain 52a, A-6020 Innsbruck (Austria)

    2011-01-15

    Single crystals of the orthoborate {pi}-ErBO{sub 3} were synthesized from Er{sub 2}O{sub 3} and B{sub 2}O{sub 3} under high-pressure/high-temperature conditions of 2 GPa and 800 {sup o}C in a Walker-type multianvil apparatus. The crystal structure was determined on the basis of single-crystal X-ray diffraction data, collected at room temperature. The title compound crystallizes in the monoclinic pseudowollastonite-type structure, space group C2/c, with the lattice parameters a=1128.4(2) pm, b=652.6(2) pm, c=954.0(2) pm, and {beta}=112.8(1){sup o} (R{sub 1}=0.0124 and wR{sub 2}=0.0404 for all data). -- graphical abstract: The first satisfying single-crystal structure determination of {pi}-ErBO{sub 3} sheds light on the extensively discussed structure of {pi}-orthoborates. The application of light pressure during the solid state synthesis yielded in high-quality crystals, due to pressure-induced crystallization. Research highlights: {yields} High-quality single crystals of {pi}-ErBO{sub 3} were prepared via high-pressure-induced crystallization. {yields} At least five different space groups for the rare-earth {pi}-orthoborates are reported. {yields} {pi}-ErBO{sub 3} is isotypic to the pseudowollastonite-type CaSiO{sub 3}. {yields} Remaining ambiguities regarding the structure of the rare-earth {pi}-orthoborates are resolved.

  8. Preparation, photoluminescent properties and luminescent dynamics of BaAlF{sub 5}:Eu{sup 2+} nanophosphors

    SciTech Connect (OSTI)

    Zhang, Wei; Hua, Ruinian; Liu, Tianqing; Zhao, Jun; Na, Liyan; Chen, Baojiu

    2014-12-15

    Graphical abstract: Rice-shaped BaAlF{sub 5}:Eu{sup 2+} nanophosphors were synthesized via one-pot hydrothermal process. The as-prepared BaAlF{sub 5}:Eu{sup 2+} are composed of many particles with an average diameter of 40 nm. When excited at 260 nm, the sharp line emission located at 361 nm of Eu{sup 2+} was observed. The optimum doping concentration of Eu{sup 2+} was confirmed to be 5 mol%. The strong ultraviolet emission of Eu{sup 2+} ions in BaAlF{sub 5}:Eu{sup 2+} nanoparticles suggests that these nanoparticles may have potential applications for sensing, solid-state lasers and spectrometer calibration. - Highlights: • BaAlF{sub 5}:Eu{sup 2+} nanophosphors were synthesized via a mild hydrothermal process. • The Van and Huang models were used to research the mechanism of concentration quenching. • The optimum doping concentration of Eu2+ was confirmed to be 5 mol%. - Abstract: Eu{sup 2+}-doped BaAlF{sub 5} nanophosphors were synthesized via a facile one-pot hydrothermal method. The final products were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and photoluminescence (PL) spectroscopy. XRD results showed that the prepared samples are single-phase. The FE-SEM and TEM images indicated that the prepared BaAlF{sub 5}:Eu{sup 2+} nanophosphors are composed of many rice-shaped particles with an average diameter of 40 nm. When excited at 260 nm, BaAlF{sub 5}:Eu{sup 2+} nanophosphors exhibit the sharp line emissions of Eu{sup 2+} at room temperature. The optimum doping concentration of Eu{sup 2+} was confirmed to be 5 mol%. The Van and Huang models were used to study the mechanism of concentration quenching and the electric dipole–dipole interaction between Eu{sup 2+} can be deduced to be a dominant for quenching fluorescence in BaAlF{sub 5}:Eu{sup 2+} nanophosphors. The strong ultraviolet emission of Eu{sup 2+} in BaAlF{sub 5}:Eu{sup 2+} nanophosphors suggests that

  9. Robust antiferromagnetism preventing superconductivity in pressurized (Ba0.61K0.39)Mn2Bi2

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gu, Dachun; Dai, Xia; Le, Congcong; Sun, Liling; Wu, Qi; Saparov, Bayrammurad; Guo, Jing; Gao, Peiwen; Zhang, Shan; Zhou, Yazhou; et al

    2014-12-05

    BaMn2Bi2 possesses an iso-structure of iron pnictide superconductors and similar antiferromagnetic (AFM) ground state to that of cuprates, therefore, it receives much more attention on its properties and is expected to be the parent compound of a new family of superconductors. When doped with potassium (K), BaMn2Bi2 undergoes a transition from an AFM insulator to an AFM metal. Consequently, it is of great interest to suppress the AFM order in the K-doped BaMn2Bi2 with the aim of exploring the potential superconductivity. Here, we report that external pressure up to 35.6 GPa cannot suppress the AFM order in the K-doped BaMn2Bi2more » to develop superconductivity in the temperature range of 300 K–1.5 K, but induces a tetragonal (T) to an orthorhombic (OR) phase transition at ~20 GPa. Theoretical calculations for the T and OR phases, on basis of our high-pressure XRD data, indicate that the AFM order is robust in the pressurized Ba0.61K0.39Mn2Bi2. Utlimately, both of our experimental and theoretical results suggest that the robust AFM order essentially prevents the emergence of superconductivity.« less

  10. Facile synthesis of Ba1-xKxFe?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 Ba1-xKxFe?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 Ba1-xKxFe?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 Tc 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.

  11. Analysis of BaBar data for three meson tau decay modes using the Tauola generator

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Shekhovtsova, Olga

    2014-11-24

    The hadronic current for the τ⁻ → π⁻π⁺π⁻ντ decay calculated in the framework of the Resonance Chiral Theory with an additional modification to include the σ meson is described. In addition, implementation into the Monte Carlo generator Tauola and fitting strategy to get the model parameters using the one-dimensional distributions are discussed. The results of the fit to one-dimensional mass invariant spectrum of the BaBar data are presented.

  12. Analysis of BaBar data for three meson tau decay modes using the Tauola generator

    SciTech Connect (OSTI)

    Shekhovtsova, Olga

    2014-11-24

    The hadronic current for the τ⁻ → π⁻π⁺π⁻ντ decay calculated in the framework of the Resonance Chiral Theory with an additional modification to include the σ meson is described. In addition, implementation into the Monte Carlo generator Tauola and fitting strategy to get the model parameters using the one-dimensional distributions are discussed. The results of the fit to one-dimensional mass invariant spectrum of the BaBar data are presented.

  13. 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.

  14. High temperature crystal structures and superionic properties of SrCl{sub 2}, SrBr{sub 2}, BaCl{sub 2} and BaBr{sub 2}

    SciTech Connect (OSTI)

    Hull, Stephen; Norberg, Stefan T.; Ahmed, Istaq; Eriksson, Sten G.; Mohn, Chris E.

    2011-11-15

    The structural properties of the binary alkaline-earth halides SrCl{sub 2}, SrBr{sub 2}, BaCl{sub 2} and BaBr{sub 2} have been investigated from ambient temperature up to close to their melting points, using the neutron powder diffraction technique. Fluorite-structured SrCl{sub 2} undergoes a gradual transition to a superionic phase at 900-1100 K, characterised by an increasing concentration of anion Frenkel defects. At a temperature of 920(3) K, the tetragonal phase of SrBr{sub 2} undergoes a first-order transition to a cubic fluorite phase. This high temperature phase shows the presence of extensive disorder within the anion sublattice, which differs from that found in superionic SrCl{sub 2}. BaCl{sub 2} and BaBr{sub 2} both adopt the cotunnite crystal structure under ambient conditions. BaCl{sub 2} undergoes a first-order structural transition at 917(5) K to a disordered fluorite-structured phase. The relationship between the (disordered) crystal structures and the ionic conductivity behaviour is discussed and the influence of the size of the mobile anion on the superionic behaviour is explored. - Graphical abstract: Anomalous behaviour of the lattice expansion of SrCl{sub 2} at temperatures of {approx}1000 K is associated with the gradual transition to a superionic phase, whilst SrBr{sub 2} undergoes a first-order structural transition ({beta}{yields}{alpha}) to a fluorite-structured superionic phase at 920(3) K. Highlights: > Anomalous behaviour of the lattice expansion of SrCl{sub 2} occurs at temperatures {approx}1000 K. > Crystal structure of {beta}-SrBr{sub 2} is described in detail. > On heating, SrBr{sub 2} and BaCl{sub 2} transform to a fluorite-structured superionic phase. > Temperature dependence of the BaCl{sub 2} and BaBr{sub 2} structures is presented. > Nature of the superionic phases within the alkaline-earth halides is discussed.

  15. Crystal and electronic structures of two new iron selenides: Ba{sub 4}Fe{sub 3}Se{sub 10} and BaFe{sub 2}Se{sub 4}

    SciTech Connect (OSTI)

    Berthebaud, David; Perez, Olivier; Tobola, Janusz; Pelloquin, Denis; Maignan, Antoine

    2015-10-15

    The new ternary selenides, Ba{sub 4}Fe{sub 3}Se{sub 10} and BaFe{sub 2}Se{sub 4,} were synthesized from a reaction of appropriate amounts of elements at high temperature in a silica sealed tube, and their structures were resolved using X-ray single crystal diffraction. BaFe{sub 2}Se{sub 4} crystallizes in the tetragonal space group I4/m with a=8.008(9) Å and c=5.483(3) Å as cell parameters. It is a new compound with a structure isotypical to the sulfide BaFe{sub 2}S{sub 4} which belongs to the infinitely adaptive structures series Ba{sub 1+x}Fe{sub 2}S{sub 4}. The second compound, Ba{sub 4}Fe{sub 3}Se{sub 10}, crystallizes in the monoclinic space group P2{sub 1}/n with a=8.8593(1) Å, b=8.8073(1) Å, c=12.2724(1) Å and β=109.037(6)° as cell parameters. It exhibits an original structure with a new type of iron selenide polyhedra. These data were consistent with the powder X-ray diffraction and TEM analyses. Their electronic structures point towards metallicity and electronic correlations for both selenides. - Graphical abstract: Experimental [010] oriented ED pattern and corresponding HREM image of Ba{sub 4}Fe{sub 3}Se{sub 10}. Image calculated with a focus and thickness to 15nm and 8 nm respectively is inserted. Bright contrasts are correlated to Se rows belonging to FeSe{sub 3}(Se{sub 2}){sup 2−}–FeSe{sub 6}–FeSe{sub 3}(Se{sub 2}){sup 2−} trimers. The corresponding structure projection is also shown. - Highlights: • Two new barium iron selenide compounds. • An original structure type Ba4Fe3Se10. • Electronic structure calculations.

  16. Engineered unique elastic modes at a BaTiO3/2x1-Ge(001) interface

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kumah, D. P.; Dogan, M.; Ngai, J. H.; Qiu, D.; Zhang, Z.; Su, D.; Specht, E. D.; Ismail-Beigi, S.; Ahn, C. H.; Walker, F. J.

    2016-03-07

    Here, the strong interaction at an interface between a substrate and thin film leads to epitaxy and provides a means of inducing structural changes in the epitaxial film. These induced material phases often exhibit technologically relevant electronic, magnetic, and functional properties. The 2×1 surface of a Ge(001) substrate applies a unique type of epitaxial constraint on thin films of the perovskite oxide BaTiO3 where a change in bonding and symmetry at the interface leads to a non-bulk-like crystal structure of the BaTiO3. While the complex crystal structure is predicted using first-principles theory, it is further shown that the details ofmore » the structure are a consequence of hidden phases found in the bulk elastic response of the BaTiO3 induced by the symmetry of forces exerted by the germanium substrate.« less

  17. Formation of BaSi{sub 2} heterojunction solar cells using transparent MoO{sub x} hole transport layers

    SciTech Connect (OSTI)

    Du, W.; Takabe, R.; Baba, M.; Takeuchi, H.; Toko, K.; Hara, K. O.; Usami, N.; Suemasu, T.

    2015-03-23

    Heterojunction solar cells that consist of 15?nm thick molybdenum trioxide (MoO{sub x}, x?BaSi{sub 2} layers were demonstrated. Rectifying current-voltage characteristics were observed when the surface of BaSi{sub 2} was exposed to air. When the exposure time was decreased to 1?min, an open circuit voltage of 200?mV and a short circuit current density of 0.5?mA/cm{sup 2} were obtained under AM1.5 illumination. The photocurrent density under a reverse bias voltage of ?1 V reached 25?mA/cm{sup 2}, which demonstrates the significant potential of BaSi{sub 2} for solar cell applications.

  18. Long-range magnetic ordering in Ba{sub 2}CoS{sub 3}: A neutron diffraction study

    SciTech Connect (OSTI)

    Headspith, D.A. [Department of Chemistry, University of Hull, Cottingham Road, Hull HU6 7RX (United Kingdom); Battle, P.D. [Inorganic Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QR (United Kingdom); Francesconi, M.G. [Department of Chemistry, University of Hull, Cottingham Road, Hull HU6 7RX (United Kingdom)], E-mail: m.g.francesconi@hull.ac.uk

    2007-10-15

    Neutron powder diffraction has been used to determine the magnetic structure of the quasi-one-dimensional compound Ba{sub 2}CoS{sub 3}, which contains linear [001] chains of vertex-sharing CoS{sub 4} tetrahedra, spaced apart by Ba{sup 2+} cations. At 1.5 K the Co{sup 2+} cations in the chains are antiferromagnetically ordered with an ordered magnetic moment of 1.97(4) {mu}{sub B} per cation aligned along [100]. Each Co{sup 2+} cation is ferromagnetically aligned with four cation in neighbouring chains and antiferromagnetically aligned with two others. - Graphical abstract: Neutron powder diffraction has been used to prove that Ba{sub 2}CoS{sub 3} shows long-range antiferromagnetic order at low temperatures, despite the quasi-one-dimensional arrangement of the CoS{sub 4} tetrahedra in the crystal structure.

  19. Structure and transport in high pressure oxygen sputter-deposited BaSnO{sub 3−δ}

    SciTech Connect (OSTI)

    Ganguly, Koustav; Ambwani, Palak; Xu, Peng; Jeong, Jong Seok; Mkhoyan, K. Andre; Leighton, C. E-mail: leighton@umn.edu; Jalan, Bharat E-mail: leighton@umn.edu

    2015-06-01

    BaSnO{sub 3} has recently been identified as a high mobility wide gap semiconductor with significant potential for room temperature oxide electronics. Here, a detailed study of the high pressure oxygen sputter-deposition, microstructure, morphology, and stoichiometry of epitaxial BaSnO{sub 3} on SrTiO{sub 3}(001) and MgO(001) is reported, optimized conditions resulting in single-phase, relaxed, close to stoichiometric films. Most significantly, vacuum annealing is established as a facile route to n-doped BaSnO{sub 3−δ}, leading to electron densities above 10{sup 19} cm{sup −3}, 5 mΩ cm resistivities, and room temperature mobility of 20 cm{sup 2} V{sup −1} s{sup −1} in 300-Å-thick films on MgO(001). Mobility limiting factors, and the substantial scope for their improvement, are discussed.

  20. The protein pheromone Er-1 of the ciliate Euplotes raikovi stimulates human T-cell activity: Involvement of interleukin-2 system

    SciTech Connect (OSTI)

    Cervia, Davide; Department of Biomedical and Clinical Sciences, Luigi Sacco University Hospital, University of Milan, Milano ; Catalani, Elisabetta; Belardinelli, Maria Cristina; Perrotta, Cristiana; Picchietti, Simona; Alimenti, Claudio; Casini, Giovanni; Fausto, Anna Maria; Vallesi, Adriana

    2013-02-01

    Water-soluble protein signals (pheromones) of the ciliate Euplotes have been supposed to be functional precursors of growth factors and cytokines that regulate cellcell interaction in multi-cellular eukaryotes. This work provides evidence that native preparations of the Euplotes raikovi pheromone Er-1 (a helical protein of 40 amino acids) specifically increases viability, DNA synthesis, proliferation, and the production of interferon-?, tumor necrosis factor-?, interleukin (IL)-1?, IL-2, and IL-13 in human Jurkat T-cells. Also, Er-1 significantly decreases the mRNA levels of the ? and ? subunits of IL-2 receptor (IL-2R), while the mRNA levels of the ? subunit appeared to be not affected. Jurkat T-cell treatments with Er-1 induced the down-regulation of the IL-2R? subunit by a reversible and time-dependent endocytosis, and increased the levels of phosphorylation of the extracellular signal-regulated kinases (ERK). The cell-type specificity of these effects was supported by the finding that Er-1, although unable to directly influence the growth of human glioma U-373 cells, induced Jurkat cells to synthesize and release factors that, in turn, inhibited the U-373 cell proliferation. Overall, these findings imply that Er-1 coupling to IL-2R and ERK immuno-enhances T-cell activity, and that this effect likely translates to an inhibition of glioma cell growth. -- Highlights: ? Euplotes pheromone Er-1 increases the growth of human Jurkat T-cells. ? Er-1 increases the T-cell production of specific cytokines. ? Er-1 activates interleukin-2 receptor and extracellular signal-regulated kinases. ? The immuno-enhancing effect of Er-1 on Jurkat cells translates to an inhibition of human glioma cell growth.

  1. Reversible Electrochemical Insertion of Lithium into Type I Ba8AlySi46-y Clathrate

    SciTech Connect (OSTI)

    Li, Ying; Raghavan, Rahul; Wagner, Nicholas; Davidowski, Stephen; Baggetto, Loic; Zhao, Ran; Cheng, Qian; Holland, Gregory p; Yarger, Jeffery L; Veith, Gabriel M; Ellis-Terrell, Carol; Miller, Michael A; Chan, Kwai; Chan, Candace

    2015-01-01

    Silicon clathrates contain cage-like structures that can encapsulate various guest atoms or molecules. Here we present an electrochemical evaluation of type I silicon clathrates based on Ba8AlySi46-y for the anode material in lithium-ion batteries. Post-cycling characterization with NMR and XRD show no discernible structural or volume changes even after electrochemical insertion of 44 Li into the clathrate structure. The observed properties are in stark contrast with lithiation of other silicon anodes, which become amorphous and suffer from larger volume changes. The lithiation/delithiation processes are proposed to occur in single phase reactions at approximately 0.2 and 0.4 V vs. Li/Li+, respectively, distinct from other diamond cubic or amorphous silicon anodes. Reversible capacities as high as 499 mAh g-1 at a 5 mA g-1 rate were observed for silicon clathrate with composition Ba8Al8.54Si37.46, corresponding to Li:Si of 1.18:1. The results show that silicon clathrates could be promising durable anodes for lithium-ion batteries.

  2. High critical currents in heavily doped (Gd,Y)Ba2Cu3Ox superconductor tapes

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Selvamanickam, V.; Gharahcheshmeh, M. Heydari; Xu, A.; Galstyan, E.; Delgado, L.; Cantoni, C.

    2015-01-20

    REBa2Cu3Ox superconductor tapes with moderate levels of dopants have been optimized for high critical current density in low magnetic fields at 77 K, but they do not exhibit exemplary performance in conditions of interest for practical applications, i.e., temperatures less than 50 K and fields of 2–30 T. Heavy doping of REBCO tapes has been avoided by researchers thus far due to deterioration in properties. Here, we report achievement of critical current densities (Jc) above 20 MA/cm2 at 30 K, 3 T in heavily doped (25 mol. % Zr-added) (Gd,Y)Ba2Cu3Ox superconductor tapes, which is more than three times higher thanmore » the Jc typically obtained in moderately doped tapes. Pinning force levels above 1000 GN/m3 have also been attained at 20 K. A composition map of lift factor in Jc (ratio of Jc at 30 K, 3 T to the Jc at 77 K, 0 T) has been developed which reveals the optimum film composition to obtain lift factors above six, which is thrice the typical value. A highly c-axis aligned BaZrO3 (BZO) nanocolumn defect density of nearly 7 × 1011 cm–2 as well as 2–3nm sized particles rich in Cu and Zr have been found in the high Jc films.« less

  3. Direct evidence of octupole deformation in neutron-rich 144Ba

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bucher, B.; Zhu, S.; Wu, C. Y.; Janssens, R. V. F.; Cline, D.; Hayes, A. B.; Albers, M.; Ayangeakaa, A. D.; Butler, P. A.; Campbell, C. M.; et al

    2016-03-17

    Here, the neutron-rich nucleus 144Ba (t1/2 = 11.5 s) is expected to exhibit some of the strongest octupole correlations among nuclei with mass numbers A less than 200. Until now, indirect evidence for such strong correlations has been inferred from observations such as enhanced E1 transitions and interleaving positive- and negative-parity levels in the ground-state band. In this experiment, the octupole strength was measured directly by sub-barrier, multistep Coulomb excitation of a post-accelerated 650-MeV 144Ba beam on a 1.0–mg/cm2 208Pb target. The measured value of the matrix element, < 31–∥M(E3)∥01+ >= 0.65(+17–23) eb3/2, corresponds to a reduced B(E3) transition probabilitymore » of 48(+25–34) W.u. This result represents an unambiguous determination of the octupole collectivity, is larger than any available theoretical prediction, and is consistent with octupole deformation.« less

  4. Final Technical Report for Award DE-FG02-98ER41080

    SciTech Connect (OSTI)

    Chen, Alan

    2014-11-14

    The prime motivation of the project at McMaster University was to carry out the critical evaluation and compilation of Nuclear Structure and Decay data, and of nuclear astrophysics data with continued participation in the United States Nuclear Data Program (US-NDP). A large body of evaluated and compiled structure data were supplied for databases such as ENSDF, XUNDL, NSR, etc. residing on webpage of National Nuclear Data Center of the Brookhaven National Laboratory, Upton, New York, USA. Thermonuclear reaction rates of importance to stellar explosions, such as novae, x-ray bursts and supernovae, were evaluated as well. This effort was closely coupled to our ongoing experimental effort, which took advantage of radioactive ion beam and stable beam facilities worldwide to study these key reaction rates. This report contains brief descriptions of the various activities together with references to all the publications in peer-reviewed journals which were the result of work carried out with the award DE-FG02-98-ER41080, during 1998-2013.

  5. THERMODYNAMIC AND KINETIC MODELING OF ADVANCED NUCLEAR FUELS - FINAL LDRD-ER REPORT

    SciTech Connect (OSTI)

    Turchi, P

    2011-11-28

    This project enhanced our theoretical capabilities geared towards establishing the basic science of a high-throughput protocol for the development of advanced nuclear fuel that should couple modern computational materials modeling and simulation tools, fabrication and characterization capabilities, and targeted high throughput performance testing experiments. The successful conclusion of this ER project allowed us to upgrade state-of-the-art modeling codes, and apply these modeling tools to ab initio energetics and thermodynamic assessments of phase diagrams of various mixtures of actinide alloys, propose a tool for optimizing composition of complex alloys for specific properties, predict diffusion behavior in diffusion couples made of actinide and transition metals, include one new equation in the LLNL phase-field AMPE code, and predict microstructure evolution during alloy coring. In FY11, despite limited funding, the team also initiated an experimental activity, with collaboration from Texas A&M University by preparing samples of nuclear fuels in bulk forms and for diffusion couple studies and metallic matrices, and performing preliminary characterization.

  6. Particle detection through the quantum counter concept in YAG:Er{sup 3+}

    SciTech Connect (OSTI)

    Borghesani, A. F.; Braggio, C. Carugno, G.; Chiossi, F.; Guarise, M.; Di Lieto, A.; Tonelli, M.; Ruoso, G.

    2015-11-09

    We report on a scheme for particle detection based on the infrared quantum counter concept. Its operation consists of a two-step excitation process of a four level system, which can be realized in rare earth-doped crystals when a cw pump laser is tuned to the transition from the second to the fourth level. The incident particle raises the atoms of the active material into a low lying, metastable energy state, triggering the absorption of the pump laser to a higher level. Following a rapid non-radiative decay to a fluorescent level, an optical signal is observed with a conventional detector. In order to demonstrate the feasibility of such a scheme, we have investigated the emission from the fluorescent level {sup 4}S{sub 3∕2} (540 nm band) in an Er{sup 3+}-doped YAG crystal pumped by a tunable titanium sapphire laser when it is irradiated with 60 keV electrons delivered by an electron gun. We have obtained a clear signature that this excitation increases the {sup 4}I{sub 13∕2} metastable level population that can efficiently be exploited to generate a detectable optical signal.

  7. Helium release and microstructural changes in Er(D,T)2-x3Hex films).

    SciTech Connect (OSTI)

    Gelles, D. S.; Browning, James Frederick; Snow, Clark Sheldon; Banks, James Clifford; Mangan, Michael A.; Rodriguez, Mark Andrew; Brewer, Luke N.; Kotula, Paul Gabriel

    2007-12-01

    Er(D,T){sub 2-x} {sup 3}He{sub x}, erbium di-tritide, films of thicknesses 500 nm, 400 nm, 300 nm, 200 nm, and 100 nm were grown and analyzed by Transmission Electron Microscopy, X-Ray Diffraction, and Ion Beam Analysis to determine variations in film microstructure as a function of film thickness and age, due to the time-dependent build-up of {sup 3}He in the film from the radioactive decay of tritium. Several interesting features were observed: One, the amount of helium released as a function of film thickness is relatively constant. This suggests that the helium is being released only from the near surface region and that the helium is not diffusing to the surface from the bulk of the film. Two, lenticular helium bubbles are observed as a result of the radioactive decay of tritium into {sup 3}He. These bubbles grow along the [111] crystallographic direction. Three, a helium bubble free zone, or 'denuded zone' is observed near the surface. The size of this region is independent of film thickness. Four, an analysis of secondary diffraction spots in the Transmission Electron Microscopy study indicate that small erbium oxide precipitates, 5-10 nm in size, exist throughout the film. Further, all of the films had large erbium oxide inclusions, in many cases these inclusions span the depth of the film.

  8. Letter Report: Borehole Flow and Horizontal Hydraulic Conductivity with Depth at Well ER-12-4

    SciTech Connect (OSTI)

    Phil L. Oberlander; Charles E. Russell

    2005-12-31

    Borehole flow and fluid temperature during pumping were measured at well ER-12-4 at the Nevada Test Site in Nye County, Nevada. This well was constructed to characterize the carbonate aquifer. The well is cased from land surface to the total depth at 1,132 m (3,713 ft bgs) below ground surface (bgs). The screened section of the well consists of alternating sections of slotted well screen and blank casing from 948 to 1,132 m bgs (3,111 to 3,713 ft bgs). Borehole flow velocity (LT-1) with depth was measured with an impeller flowmeter from the top of the screened section to the maximum accessible depth while the well was pumped and under ambient conditions. A complicating factor to data interpretation is that the well was not filter packed and there is upward and downward vertical flow in the open annulus under ambient and pumping conditions. The open annulus in the well casing likely causes the calculated borehole flow rates being highly nonrepresentative of inflow from the formation. Hydraulic conductivities calculated under these conditions would require unsupportable assumptions and would be subject to very large uncertainties. Borehole hydraulic conductivities are not presented under these conditions.

  9. Analysis of Well ER-6-2 Testing, Yucca Flat FY 2004 Testing Program, Nevada Test Site, Nye County, Nevada, Rev. No.: 0

    SciTech Connect (OSTI)

    Greg Ruskauff

    2005-07-01

    This report documents the analysis of data collected for Well ER-6-2 during fiscal year (FY) 2004 Yucca Flat well development and testing program (herein referred to as the ''testing program''). Participants in Well ER-6-2 field development and hydraulic testing activities were: Stoller-Navarro Joint Venture (SNJV), Bechtel Nevada (BN), Desert Research Institute (DRI), Los Alamos National Laboratory (LANL), Lawrence Livermore National Laboratory (LLNL), U.S. Geological Survey (USGS), and the University of Nevada, Las Vegas-Harry Reid Center (UNLV-HRC). The analyses of data collected from the Well ER-6-2 testing program were performed by the SNJV.

  10. Unit-cell thick BaTiO{sub 3} blocks octahedral tilt propagation across oxide heterointerface

    SciTech Connect (OSTI)

    Kan, Daisuke Aso, Ryotaro; Kurata, Hiroki; Shimakawa, Yuichi

    2014-05-14

    We fabricated SrRuO{sub 3}/BaTiO{sub 3}/GdScO{sub 3} heterostructures in which the BaTiO{sub 3} layer is one unit cell thick by pulsed laser deposition and elucidated how the BaTiO{sub 3} layer influences structural and magneto-transport properties of the SrRuO{sub 3} layer through octahedral connections across the heterointerface. Our X-ray-diffraction-based structural characterizations show that while an epitaxial SrRuO{sub 3} layer grown directly on a GdScO{sub 3} substrate is in the monoclinic phase with RuO{sub 6} octahedral tilts, a one-unit-cell-thick BaTiO{sub 3} layer inserted between SrRuO{sub 3} and GdScO{sub 3} stabilizes the tetragonal SrRuO{sub 3} layer with largely reduced RuO{sub 6} tilts. Our high-angle annular dark-field and annular bright-field scanning transmission electron microscopy observations provide an atomic-level view of the octahedral connections across the heterostructure and reveal that the BaTiO{sub 3} layer only one unit cell thick is thick enough to stabilize the RuO{sub 6}-TiO{sub 6} octahedral connections with negligible in-plane oxygen atomic displacements. This results in no octahedral tilts propagating into the SrRuO{sub 3} layer and leads to the formation of a tetragonal SrRuO{sub 3} layer. The magneto-transport property characterizations also reveal a strong impact of the octahedral connections modified by the inserted BaTiO{sub 3} layer on the spin-orbit interaction of the SrRuO{sub 3} layer. The SrRuO{sub 3} layer on BaTiO{sub 3}/ GdScO{sub 3} has in-plane magnetic anisotropy. This is in contrast to the magnetic anisotropy of the monoclinic SrRuO{sub 3} films on the GdScO{sub 3} substrate, in which the easy axis is ?45 to the film surface normal. Our results demonstrate that the one-unit-cell-thick layer of BaTiO{sub 3} can control and manipulate the interfacial octahedral connection closely linked to the structure-property relationship of heterostructures.

  11. Role of magnetism in superconductivity of BaFe2As2: Study of 5d Au-doped crystals

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Li, Li; Cao, Huibo; McGuire, Michael A.; Kim, J. S.; Stewart, G. R.; Sefat, Athena Safa

    2015-09-09

    We investigate properties of BaFe2As2 (122) single crystals upon gold doping, which is the transition metal with the highest atomic weight. The Au substitution into the FeAs-planes of 122 crystal structure (Au-122) is only possible up to a small amount of ~3%. We find that 5d is more effective in reducing magnetism in 122 than its counter 3d Cu, and this relates to superconductivity. We provide evidence of short-range magnetic fluctuations and local lattice inhomogeneities that may prevent strong percolative superconductivity in Ba(Fe1-xAux)2As2.

  12. Morphology and Composition cycle of BaO/Al2O3 NSR Catalysts during NO2

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Uptake and Release: A multi spectroscopy and microscopy study | Department of Energy Morphology and Composition cycle of BaO/Al2O3 NSR Catalysts during NO2 Uptake and Release: A multi spectroscopy and microscopy study Morphology and Composition cycle of BaO/Al2O3 NSR Catalysts during NO2 Uptake and Release: A multi spectroscopy and microscopy study 2005 Diesel Engine Emissions Reduction (DEER) Conference Presentations and Posters 2005_deer_kim.pdf (868.73 KB) More Documents &

  13. Completion Report for the Well ER-6-2 Site Corrective Action Unit 97: Yucca Flat - Climax Mine

    SciTech Connect (OSTI)

    NSTec Environmental Management

    2008-03-01

    Well ER-6-2 and its satellite hole, Well ER-6-2 No.1, were drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. Well ER-6-2 was drilled in two stages in 1993 and 1994; the satellite hole, Well ER-6-2 No.1 was drilled nearby in 1993 but was abandoned. The wells were drilled as part of a hydrogeologic investigation program for the Yucca Flat-Climax Mine Corrective Action Unit Number 97, in the northeastern portion of the Nevada Test Site. The wells are located in Yucca Flat, within Area 6 of the Nevada Test Site. The wells provided information regarding the radiological and hydrogeological environment in a potentially down-gradient position from tests conducted in northern and central Yucca Flat. Construction of Well ER-6-2 began with a 1.2-meter-diameter surface conductor hole, which was drilled and cased off to a depth of 30.8 meters below the surface. A 50.8-centimeter diameter surface hole was then rotary drilled to the depth of 578.5 meters and cased off to the depth of 530.4 meters. The hole diameter was then reduced to 27.0 centimeters, and the borehole was advanced to a temporary depth of 611.4 meters. The borehole was conventionally cored to a total depth of 1,045 meters with a diameter of 14.0 centimeters. Borehole sloughing required cementing and re-drilling of several zones. The open-hole completion accesses the lower carbonate aquifer, the CP thrust fault, and the upper clastic confining unit. A fluid level depth of 543.2 meters was most recently measured in the open borehole in September 2007. No radionuclides were encountered during drilling. The satellite hole Well ER-6-2 No.1 was drilled approximately 15.2 meters north of Well ER-6-2 on the same drill pad. This was planned to be used as an observation well during future hydrologic testing at Well ER-6-2; however, the satellite hole was abandoned at

  14. Spatially resolved penetration depth measurements and vortex manipulation in the ferromagnetic superconductor ErNi2B2C

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wulferding, Dirk; Yang, Ilkyu; Yang, Jinho; Lee, Minkyung; Choi, Hee Cheul; Bud'ko, Sergey L.; Canfield, Paul C.; Yeom, Han Woong; Kim, Jeehoon

    2015-07-31

    We present a local probe study of the magnetic superconductor ErNi2B2C, using magnetic force microscopy at sub-Kelvin temperatures. ErNi2B2C is an ideal system to explore the effects of concomitant superconductivity and ferromagnetism. At 500 mK, far below the transition to a weakly ferromagnetic state, we directly observe a structured magnetic background on the micrometer scale. We determine spatially resolved absolute values of the magnetic penetration depth λ and study its temperature dependence as the system undergoes magnetic phase transitions from paramagnetic to antiferromagnetic, and to weak ferromagnetic, all within the superconducting regime. We estimate the absolute pinning force of Abrikosovmore » vortices, which shows a position dependence and temperature dependence as well, and discuss the possibility of the purported spontaneous vortex formation.« less

  15. Interaction between BaCO{sub 3} and OPC/BFS composite cements at 20 {sup o}C and 60 {sup o}C

    SciTech Connect (OSTI)

    Utton, C.A.; Gallucci, E.; Hill, J.; Milestone, N.B.

    2011-03-15

    A BaCO{sub 3} slurry, containing radioactive {sup 14}C, is produced during the reprocessing of spent nuclear fuel. This slurry is encapsulated in a Portland-blastfurnace slag composite cement. The effect of BaCO{sub 3} on the hydration of OPC and Portland-blastfurnace slag cements has been studied in this work. Samples containing a simulant BaCO{sub 3} slurry were cured for up to 720 days at 20 and 60 {sup o}C and analysed by XRD, SEM(EDX) and ICC. BaCO{sub 3} reacted with OPC to precipitate BaSO{sub 4} from a reaction between soluble sulfate and BaCO{sub 3}. Calcium monocarboaluminate subsequently formed from the carbonate released. The monocarboaluminate precipitated as crystals in voids formed during hydration. At 60 {sup o}C in OPC, it was not identified by XRD, suggesting the phase is unstable in this system around this temperature. In the Portland-blastfurnace slag cements containing BaCO{sub 3}, less monocarboaluminate and BaSO{sub 4} were formed, but the hydration of BFS was promoted and monocarboaluminate was stable up to 60 {sup o}C.

  16. Synthesis, Crystal and Electronic Structures of the Pnictides AE3TrPn3 (AE = Sr, Ba; Tr = Al, Ga; Pn = P, As)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Stoyko, Stanislav; Voss, Leonard; He, Hua; Bobev, Svilen

    2015-09-24

    New ternary arsenides AE3TrAs3 (AE = Sr, Ba; Tr = Al, Ga) and their phosphide analogs Sr3GaP3 and Ba3AlP3 have been prepared by reactions of the respective elements at high temperatures. Single-crystal X-ray diffraction studies reveal that Sr3AlAs3 and Ba3AlAs3 adopt the Ba3AlSb3-type structure (Pearson symbol oC56, space group Cmce, Z = 8). This structure is also realized for Sr3GaP3 and Ba3AlP3. Likewise, the compounds Sr3GaAs3 and Ba3GaAs3 crystallize with the Ba3GaSb3-type structure (Pearson symbol oP56, space group Pnma, Z = 8). Both structures are made up of isolated pairs of edge-shared AlPn4 and GaPn4 tetrahedra (Pn = pnictogen, i.e.,more » P or As), separated by the alkaline-earth Sr2+ and Ba2+ cations. In both cases, there are no homoatomic bonds, hence, regardless of the slightly different atomic arrangements, both structures can be rationalized as valence-precise [AE2+]3[Tr3+][Pn3-]3, or rather [AE2+]6[Tr2Pn6]12-, i.e., as Zintl phases.« less

  17. Gain dynamics in a soft X-ray laser ampli er perturbed by a strong injected X-ray eld

    SciTech Connect (OSTI)

    Wang, Yong; Wang, Shoujun; Oliva, E; Lu, L; Berrill, Mark A; Yin, Liang; Nejdl, J; Luther, Brad; Proux, C; Le, T. T.; Dunn, James; Ros, D; Zeitoun, Philippe; Rocca, Jorge

    2014-01-01

    Seeding soft X-ray plasma ampli ers with high harmonics has been demonstrated to generate high-brightness soft X-ray laser pulses with full spatial and temporal coherence. The interaction between the injected coherent eld and the swept-gain medium has been modelled. However, no exper- iment has been conducted to probe the gain dynamics when perturbed by a strong external seed eld. Here, we report the rst X-ray pump X-ray probe measurement of the nonlinear response of a plasma ampli er perturbed by a strong soft X-ray ultra-short pulse. We injected a sequence of two time-delayed high-harmonic pulses (l518.9 nm) into a collisionally excited nickel-like molybdenum plasma to measure with femto-second resolution the gain depletion induced by the saturated ampli cation of the high-harmonic pump and its subsequent recovery. The measured fast gain recovery in 1.5 1.75 ps con rms the possibility to generate ultra-intense, fully phase-coherent soft X-ray lasers by chirped pulse ampli cation in plasma ampli ers.

  18. Close-Out Report of DOE Grant DE-FG02-91ER40682 for November 1, 2009 - April 30, 2013

    SciTech Connect (OSTI)

    Paulini, Manfred

    2013-07-20

    This document is the close-out report of Grant DE-FG02-91ER40682 from the Carnegie Mellon University (CMU) High-Energy Physics (HEP) Group to the U.S. Department of Energy (DOE).

  19. Potential variation around grain boundaries in BaSi{sub 2} films grown on multicrystalline silicon evaluated using Kelvin probe force microscopy

    SciTech Connect (OSTI)

    Baba, Masakazu; Tsukahara, Daichi; Toko, Kaoru; Hara, Kosuke O.; Usami, Noritaka; Sekiguchi, Takashi; Suemasu, Takashi

    2014-12-21

    Potential variations across the grain boundaries (GBs) in a 100?nm thick undoped n-BaSi{sub 2} film on a cast-grown multicrystalline Si (mc-Si) substrate are evaluated using Kelvin probe force microscopy (KFM). The ?-2? X-ray diffraction pattern reveals diffraction peaks, such as (201), (301), (410), and (411) of BaSi{sub 2}. Local-area electron backscatter diffraction reveals that the a-axis of BaSi{sub 2} is tilted slightly from the surface normal, depending on the local crystal plane of the mc-Si. KFM measurements show that the potentials are not significantly disordered in the grown BaSi{sub 2}, even around the GBs of mc-Si. The potentials are higher at GBs of BaSi{sub 2} around Si GBs that are formed by grains with a Si(111) face and those with faces that deviate slightly from Si(111). Thus, downward band bending occurs at these BaSi{sub 2} GBs. Minority carriers (holes) undergo a repelling force near the GBs, which may suppress recombination as in the case of undoped n-BaSi{sub 2} epitaxial films on a single crystal Si(111) substrate. The barrier height for hole transport across the GBs varies in the range from 10 to 55?meV. The potentials are also higher at the BaSi{sub 2} GBs grown around Si GBs composed of grains with Si(001) and Si(111) faces. The barrier height for hole transport ranges from 5 to 55?meV. These results indicate that BaSi{sub 2} GBs formed on (111)-dominant Si surfaces do not have a negative influence on the minority-carrier properties, and thus BaSi{sub 2} formed on underlayers, such as (111)-oriented Si or Ge and on (111)-oriented mc-Si, can be utilized as a solar cell active layer.

  20. Magnetic and nonlinear optical properties of BaTiO{sub 3} nanoparticles

    SciTech Connect (OSTI)

    Ramakanth, S.; Venugopal Rao, S.; Hamad, Syed; James Raju, K. C.

    2015-05-15

    In our earlier studies the BaTiO{sub 3} samples were processed at higher temperatures like 1000{sup o}C and explained the observed magnetism in it. It is found that the charge transfer effects are playing crucial role in explaining the observed ferromagnetism in it. In the present work the samples were processed at lower temperatures like 650{sup o}C-800{sup o}C. The carrier densities in these particles were estimated to be ∼ 10{sup 19}-10{sup 20}/cm{sup 3} range. The band gap is in the range of 2.53eV to 3.2eV. It is observed that magnetization increased with band gap narrowing. The higher band gap narrowed particles exhibited increased magnetization with a higher carrier density of 1.23×10{sup 20}/cm{sup 3} near to the Mott critical density. This hint the exchange interactions between the carriers play a dominant role in deciding the magnetic properties of these particles. The increase in charge carrier density in this undoped BaTiO{sub 3} is because of oxygen defects only. The oxygen vacancy will introduce electrons in the system and hence more charge carriers means more oxygen defects in the system and increases the exchange interactions between Ti3+, Ti4+, hence high magnetic moment. The coercivity is increased from 23 nm to 31 nm and then decreased again for higher particle size of 54 nm. These particles do not show photoluminescence property and hence it hints the absence of uniformly distributed distorted [TiO5]-[TiO6] clusters formation and charge transfer between them. Whereas these charge transfer effects are vital in explaining the observed magnetism in high temperature processed samples. Thus the variation of magnetic properties like magnetization, coercivity with band gap narrowing, particle size and charge carrier density reveals the super paramagnetic nature of BaTiO{sub 3} nanoparticles. The nonlinear optical coefficients extracted from Z-scan studies suggest that these are potential candidates for optical imaging and signal processing

  1. Completion Report for Model Evaluation Well ER-5-5: Corrective Action Unit 98: Frenchman Flat

    SciTech Connect (OSTI)

    NSTec Underground Test Area and Boreholes Programs and Operations

    2013-01-18

    Model Evaluation Well ER-5-5 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of Nevada Environmental Management Operations at the Nevada National Security Site (formerly known as the Nevada Test Site). The well was drilled in July and August 2012 as part of a model evaluation well program in the Frenchman Flat area of Nye County, Nevada. The primary purpose of the well was to provide detailed geologic, hydrogeologic, chemical, and radiological data that can be used to test and build confidence in the applicability of the Frenchman Flat Corrective Action Unit flow and transport models for their intended purpose. In particular, this well was designed to obtain data to evaluate the uncertainty in model forecasts of contaminant migration from the upgradient underground nuclear test MILK SHAKE, conducted in Emplacement Hole U-5k in 1968, which were considered to be uncertain due to the unknown extent of a basalt lava-flow aquifer present in this area. Well ER-5-5 is expected to provide information to refine the Phase II Frenchman Flat hydrostratigraphic framework model, if necessary, as well as to support future groundwater flow and transport modeling. The 31.1-centimeter (cm) diameter hole was drilled to a total depth of 331.3 meters (m). The completion string, set at the depth of 317.2 m, consists of 16.8-cm stainless-steel casing hanging from 19.4-cm carbon-steel casing. The 16.8-cm stainless-steel casing has one slotted interval open to the basalt lava-flow aquifer and limited intervals of the overlying and underlying alluvial aquifer. A piezometer string was also installed in the annulus between the completion string and the borehole wall. The piezometer is composed of 7.3-cm stainless-steel tubing suspended from 6.0-cm carbon-steel tubing. The piezometer string was landed at 319.2 m, to monitor the basalt lava-flow aquifer. Data collected during and shortly after hole construction include

  2. Analysis of in-situ electrical conductivity data from the HFIR TRIST-ER1 experiment

    SciTech Connect (OSTI)

    Zinkle, S.J.; Snead, L.L.; Shikama, T.

    1997-08-01

    The current vs. applied voltage data generated from the HFIR TRIST-ER1 experiment have been analyzed to determine the electrical conductivity of the 15 aluminum oxide specimens and the MgO-insulated electrical cables as a function of irradiation dose. With the exception of the 0.05%Cr-doped sapphire (ruby) specimen, the electrical conductivity of the alumina specimens remained at the expected radiation induced conductivity (RIC) level of <10{sup -6} S/m during full-power reactor irradiation (10-16 kGy/s) at 450-500{degrees}C up to a maximum dose of {approximately}3 dpa. The ruby specimen showed a rapid initial increase in conductivity to {approximately}2 x 10{sup -4} S/m after {approximately}0.1 dpa, followed by a gradual decrease to <1 x 10{sup -6} S/m after 2 dpa. Nonohmic electrical behavior was observed in all of the specimens, and was attributed to preferential attraction of ionized electrons in the capsule gas to the unshielded low-side bare electrical leads emanating from the subcapsules. The electrical conductivity was determined from the slope of the specimen current vs. voltage curve at negative voltages, where the gas ionization effect was minimized. Dielectric breakdown tests performed on unirradiated mineral-insulated coaxial cables identical to those used in the high voltage coaxial cables during the 3-month irradiation is attributable to thermal dielectric breakdown in the glass seals at the end of the cables, as opposed to a radiation-induced electrical degradation (RIED) effect.

  3. Completion Report for Well ER-12-3 Corrective Action Unit 99: Rainier Mesa - Shoshone Mountain

    SciTech Connect (OSTI)

    U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office; Bechtel Nevada Corporation

    2006-05-01

    Well ER-12-3 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office, in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. The well was drilled in March and April 2005 as part of a hydrogeologic investigation program for the Rainier Mesa-Shoshone Mountain Corrective Action Unit. The overall purpose of the well was to gather subsurface data to better characterize the hydrogeology of central Rainier Mesa, especially in the older Tertiary volcanic rocks and Paleozoic sedimentary rocks. The main 47.0-centimeter hole was drilled to a depth of 799.2 meters and cased with 33.97-centimeter casing to 743.1 meters. The hole diameter was then decreased to 31.1 centimeters, and the well was drilled to a total depth of 1,496.0 meters. The completion string consisted of 13.97-centimeter stainless steel casing, with two slotted intervals open to the lower carbonate aquifer, suspended from 19.37-centimeter carbon steel casing. A piezometer string was installed outside the 33.97-centimeter casing to a depth of 467.1 meters to monitor a zone of perched water within the Tertiary volcanic section. Data gathered during and shortly after hole construction include composite drill cuttings samples collected every 3 meters (extra cuttings samples were collected from the Paleozoic rocks for paleontological analyses), sidewall core samples from 35 depths, various geophysical logs, and water level measurements. These data indicate that the well penetrated 674.2 meters of Tertiary volcanic rocks and 821.7 meters of Paleozoic dolomite and limestone. Forty-nine days after the well was completed, but prior to well development and testing, the water level inside the main hole was tagged at the depth of 949.1 meters, and the water level inside the piezometer string was tagged at 379.9 meters.

  4. Idaho National Engineering Laboratory (INEL) Environmental Restoration (ER) Program Baseline Safety Analysis File (BSAF)

    SciTech Connect (OSTI)

    1995-09-01

    The Baseline Safety Analysis File (BSAF) is a facility safety reference document for the Idaho National Engineering Laboratory (INEL) environmental restoration activities. The BSAF contains information and guidance for safety analysis documentation required by the U.S. Department of Energy (DOE) for environmental restoration (ER) activities, including: Characterization of potentially contaminated sites. Remedial investigations to identify and remedial actions to clean up existing and potential releases from inactive waste sites Decontamination and dismantlement of surplus facilities. The information is INEL-specific and is in the format required by DOE-EM-STD-3009-94, Preparation Guide for U.S. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports. An author of safety analysis documentation need only write information concerning that activity and refer to BSAF for further information or copy applicable chapters and sections. The information and guidance provided are suitable for: {sm_bullet} Nuclear facilities (DOE Order 5480-23, Nuclear Safety Analysis Reports) with hazards that meet the Category 3 threshold (DOE-STD-1027-92, Hazard Categorization and Accident Analysis Techniques for Compliance with DOE Order 5480.23, Nuclear Safety Analysis Reports) {sm_bullet} Radiological facilities (DOE-EM-STD-5502-94, Hazard Baseline Documentation) Nonnuclear facilities (DOE-EM-STD-5502-94) that are classified as {open_quotes}low{close_quotes} hazard facilities (DOE Order 5481.1B, Safety Analysis and Review System). Additionally, the BSAF could be used as an information source for Health and Safety Plans and for Safety Analysis Reports (SARs) for nuclear facilities with hazards equal to or greater than the Category 2 thresholds, or for nonnuclear facilities with {open_quotes}moderate{close_quotes} or {open_quotes}high{close_quotes} hazard classifications.

  5. Final Report for DOE Grant DE-FG02-06ER64160 Retrieval of Cloud Properties and Direct Testing of Cloud and Radiation Parameterizations using ARM Observations.

    SciTech Connect (OSTI)

    Donovan, David Patrick

    2013-07-26

    This report briefly summaries the work performed at KNMI under DOE Grant DE-FG02-06ER64160 which, in turn was conducted in support of DOE Grant DE-FG02-90ER61071 lead by E. Clothieux of Penn. State U. The specific work at KNMI revolved around the development and application of the EarthCARE simulator to ground-based multi-sensor simulations.

  6. 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 (α-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

  7. Production of highly-enriched 134Ba for a reference material for isotope dilution mass spectrometry measurements

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Horkley, J. J.; Carney, K. P.; Gantz, E. M.; Davies, J. E.; Lewis, R. R.; Crow, J. P.; Poole, C. A.; Grimes, T. S.; Giglio, J. J.

    2015-03-17

    Isotope dilution mass spectrometry (IDMS) is an analytical technique capable of providing accurate and precise quantitation of trace isotope abundance and assay providing measurement uncertainties below 1 %. To achieve these low uncertainties, the IDMS method ideally utilizes chemically pure “spike” solutions that consist of a single highly enriched isotope that is well-characterized relating to the abundance of companion isotopes and concentration in solution. To address a current demand for accurate 137Cs/137Ba ratio measurements for “age” determination of radioactive 137Cs sources, Idaho National Laboratory (INL) is producing enriched 134Ba isotopes that are tobe used for IDMS spikes to accurately determinemore » 137Ba accumulation from the decay of 137Cs. The final objective of this work it to provide a homogenous set of reference materials that the National Institute of Standards and Technology can certify as standard reference materials used for IDMS. The process that was developed at INL for the separation and isolation of Ba isotopes, chemical purification of the isotopes in solution, and the encapsulation of the materials will be described.« less

  8. Production of highly-enriched 134Ba for a reference material for isotope dilution mass spectrometry measurements

    SciTech Connect (OSTI)

    Horkley, J. J.; Carney, K. P.; Gantz, E. M.; Davies, J. E.; Lewis, R. R.; Crow, J. P.; Poole, C. A.; Grimes, T. S.; Giglio, J. J.

    2015-03-17

    Isotope dilution mass spectrometry (IDMS) is an analytical technique capable of providing accurate and precise quantitation of trace isotope abundance and assay providing measurement uncertainties below 1 %. To achieve these low uncertainties, the IDMS method ideally utilizes chemically pure “spike” solutions that consist of a single highly enriched isotope that is well-characterized relating to the abundance of companion isotopes and concentration in solution. To address a current demand for accurate 137Cs/137Ba ratio measurements for “age” determination of radioactive 137Cs sources, Idaho National Laboratory (INL) is producing enriched 134Ba isotopes that are tobe used for IDMS spikes to accurately determine 137Ba accumulation from the decay of 137Cs. The final objective of this work it to provide a homogenous set of reference materials that the National Institute of Standards and Technology can certify as standard reference materials used for IDMS. The process that was developed at INL for the separation and isolation of Ba isotopes, chemical purification of the isotopes in solution, and the encapsulation of the materials will be described.

  9. Production of highly-enriched 134Ba for a reference material for isotope dilution mass spectrometry measurements

    SciTech Connect (OSTI)

    J.J. Horkley; K.P E.M. Gantz; J.E. Davis; R.R. Lewis; J.P. Crow; C.A. Poole; T.S. Grimes; J.J. Giglio

    2015-03-01

    t Isotope dilution mass spectrometry (IDMS) is an analytical technique capable of providing accurate and precise quantitation of trace isotope abundance and assay providing measurement uncertainties below 1 %. To achieve these low uncertainties, the IDMS method ideally utilizes chemically pure spike solutions that consist of a single highly enriched isotope that is well-characterized relating to the abundance of companion isotopes and concentration in solution. To address a current demand for accurate 137Cs/137Ba ratio measurements for age determination of radioactive 137Cs sources, Idaho National Laboratory (INL) is producing enriched 134Ba isotopes that are tobe used for IDMS spikes to accurately determine 137Ba accumulation from the decay of 137Cs. The final objective of this work it to provide a homogenous set of reference materials that the National Institute of Standards and Technology can certify as standard reference materials used for IDMS. The process that was developed at INL for the separation and isolation of Ba isotopes, chemical purification of the isotopes in solution,

  10. Production of highly-enriched 134Ba for a reference material for isotope dilution mass spectrometry measurements

    SciTech Connect (OSTI)

    Horkley, J. J.; Carney, K. P.; Gantz, E. M.; Davies, J. E.; Lewis, R. R.; Crow, J. P.; Poole, C. A.; Grimes, T. S.; Giglio, J. J.

    2015-03-17

    Isotope dilution mass spectrometry (IDMS) is an analytical technique capable of providing accurate and precise quantitation of trace isotope abundance and assay providing measurement uncertainties below 1 %. To achieve these low uncertainties, the IDMS method ideally utilizes chemically pure spike solutions that consist of a single highly enriched isotope that is well-characterized relating to the abundance of companion isotopes and concentration in solution. To address a current demand for accurate 137Cs/137Ba ratio measurements for age determination of radioactive 137Cs sources, Idaho National Laboratory (INL) is producing enriched 134Ba isotopes that are tobe used for IDMS spikes to accurately determine 137Ba accumulation from the decay of 137Cs. The final objective of this work it to provide a homogenous set of reference materials that the National Institute of Standards and Technology can certify as standard reference materials used for IDMS. The process that was developed at INL for the separation and isolation of Ba isotopes, chemical purification of the isotopes in solution, and the encapsulation of the materials will be described.

  11. Thermoelectric and Structural Characterization of Ba2Ho(Cu3-xCox)O6+y

    SciTech Connect (OSTI)

    Wong-Ng, W.; Li, Q.; Yang, Z.; Hu, Y.F.; Huang, Q.; Lowhorn, N.; Otani, M.; Kaduk, J.A.

    2009-03-18

    The search for thermoelectric materials for power generation and for solid-state cooling has led to increased interest of layered cobalt-containing oxides because of their thermal stability at high temperature and their desirable thermoelectric properties. This paper examines the effect of substitution of Co in the layered pervoskite Ba{sub 2}Ho(Cu{sub 3-x}Co{sub x})O{sub 6+y} (x = 0.3, 0.4, 0.5, 0.6, and 1.0). Structural analysis using the neutron Rietveld refinement technique reveals that when x {le} 0.4, Co substitutes mainly for Cu in the 'chain sites' of the Ba{sub 2}Ho(Cu{sub 3-x}Co{sub x})O{sub 6+y} structure. As x > 0.4, Co also enters in the Cu-O 'plane sites' as well. The thermoelectric properties of polycrystalline Ba{sub 2}Ho(Cu{sub 3-x}Co{sub x})O{sub 6+y} samples were studied in the temperature range of 10-390 K. In general, as the cobalt content x increases, the resistivity and Seebeck coefficient of these samples increase while the thermal conductivity decreases. Among the five Ba{sub 2}Ho(Cu{sub 3-x}Co{sub x})O{sub 6+y} compositions, the x = 0.4 member gives the highest figure of merit ZT of {approx} 0.02 at approximately 270 K.

  12. Long-range ferromagnetic order induced by a donor impurity band exchange in SnO{sub 2}:Er{sup 3+} nanoparticles

    SciTech Connect (OSTI)

    Aragn, F. H.; Coaquira, J. A. H.; Chitta, V. A.; Hidalgo, P.; Brito, H. F.

    2013-11-28

    In this work, the structural and magnetic properties of Er-doped SnO{sub 2} (SnO{sub 2}:Er) nanoparticles are reported. The SnO{sub 2}:Er nanoparticles have been synthesized by a polymer precursor method with Er content from 1.0% to 10.0%. X-ray diffraction results indicate the formation of only the rutile-type structure in all samples. The estimated mean crystallite size shows a decrease from ?10 to ?4?nm when the Er content is increased from 1.0% to 10.0%. The particle size values have been corroborated by transmission electron microscopy technique. The thermal dependence of the magnetization is consistent with the 3+ oxidation state of erbium ions for all samples. A strong paramagnetic-like behavior coexisting with a ferromagnetic phase has been determined for samples with Er content below 5.0%. Above this concentration, only a paramagnetic behavior has been determined. Isothermal magnetization curves are consistent with the occurrence of long-range ferromagnetic order mediated by donor electrons forming bound magnetic polarons which overlap to produce a spin-split impurity band.

  13. Microscopic description of spherical to {gamma}-soft shape transitions in Ba and Xe nuclei

    SciTech Connect (OSTI)

    Li, Z. P.; Niksic, T.; Vretenar, D.; Meng, J.

    2010-03-15

    The rapid transition between spherical and {gamma}-soft shapes in Ba and Xe nuclei in the mass region A>=130 is analyzed using excitation spectra and collective wave functions obtained by diagonalization of a five-dimensional Hamiltonian for quadrupole vibrational and rotational degrees of freedom, with parameters determined by constrained self-consistent relativistic mean-field calculations for triaxial shapes. The results reproduce the characteristic evolution of excitation spectra and E2 transition probabilities, and in general, a good agreement with available data is obtained. The calculated spectra display fingerprints of a second-order shape phase transition that can approximately be described by analytic solutions corresponding to the E(5) dynamical symmetry.

  14. Proton Form Factors And Related Processes in BaBar by ISR

    SciTech Connect (OSTI)

    Ferroli, R.B.; /Enrico Fermi Ctr., Rome /INFN, Rome

    2007-02-12

    BaBar has measured with unprecedented accuracy e{sup +}e{sup -} {yields} p{bar p} from the threshold up to Q{sub p{bar p}}{sup 2} {approx} 20 GeV{sup 2}/c{sup 4}, finding out an unexpected cross section, with plateaux and drops. In particular it is well established a sharp drop near threshold, where evidence for structures in multihadronic channels has also been found. Other unexpected and spectacular features of the Nucleon form factors are reminded, the behavior of space-like G{sub E}{sup p}/G{sub M}{sup p} and the neutron time-like form factors.

  15. Enhanced thermoelectric performance of (Ba,In) double-filled skutterudites via randomly arranged micropores

    SciTech Connect (OSTI)

    Yu, Jian; Zhao, Wen-Yu E-mail: zhangqj@whut.edu.cn; Wei, Ping; Zhu, Wan-Ting; Zhou, Hong-Yu; Liu, Zhi-Yuan; Tang, Ding-Guo; Lei, Bing; Zhang, Qing-Jie E-mail: zhangqj@whut.edu.cn

    2014-04-07

    Porous (Ba,In) double-filled skutterudite materials with pore diameter about 14??m were prepared by the decomposition of metastable ZnSb inclusions induced by the Zn sublimation. Transport measurements revealed that the Seebeck coefficient was increased due to the electron filtering effect induced by nanostructures in the surfaces of pores, the electrical conductivity was almost unchanged because of the percolation effect of conducted network composed of filled skutterudites, and the lattice thermal conductivity was dramatically suppressed due to the enhanced pore-edge boundary scattering of long-wavelength phonons. As a result, a maximum ZT of 1.36 was obtained, increased by 22.5% as compared to that of the bulk material with same chemical composition. This work demonstrates that by introducing porous structures is thought to be an efficient approach to improve the thermoelectric performance of bulk materials.

  16. Computer modeling of Y-Ba-Cu-O thin film deposition and growth

    SciTech Connect (OSTI)

    Burmester, C.; Gronsky, R. ); Wille, L. . Dept. of Physics)

    1991-07-01

    The deposition and growth of epitaxial thin films of YBa{sub 2}Cu{sub 3}O{sub 7} are modeled by means of Monte Carlo simulations of the deposition and diffusion of Y, Ba, and Cu oxide particles. This complements existing experimental characterization techniques to allow the study of kinetic phenomena expected to play a dominant role in the inherently non-equilibrium thin film deposition process. Surface morphologies and defect structures obtained in the simulated films are found to closely resemble those observed experimentally. A systematic study of the effects of deposition rate and substrate temperature during in-situ film fabrication reveals that the kinetics of film growth can readily dominate the structural formation of the thin film. 16 refs., 4 figs.

  17. Magnetic structure and spin excitations in BaMn2Bi2

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Calder, Stuart A.; Saparov, Bayrammurad I; Cao, H. B.; Niedziela, Jennifer L.; Lumsden, Mark D.; Sefat, Athena Safa; Christianson, Andrew D.

    2014-02-19

    We present a single crystal neutron scattering study of BaMn2Bi2, a recently synthesized material with the same ThCr2Si2type structure found in several Fe-based unconventional superconducting materials. We show long range magnetic order, in the form of a G-type antiferromagnetic structure, to exist up to 390 K with an indication of a structural transition at 100 K. Utilizing inelastic neutron scattering we observe a spin-gap of 16 meV, with spin-waves extending up to 55 meV. We find these magnetic excitations are well fit to a J1-J2-Jc Heisenberg model and present values for the exchange interactions. The spin wave spectrum appears tomore » be unchanged by the 100 K structural phase transition.« less

  18. Bose-Einstein condensation of triplons in Ba3Cr2O8

    SciTech Connect (OSTI)

    Jaime, Marcelo [Los Alamos National Laboratory; Kohama, Y [Los Alamos National Laboratory; Aczel, A [MCMASTER UNIV; Ninios, K [UNIV OF FL; Chan, H [UNIV OF FL; Balicas, L [NHMFL; Dabkowska, H [MCMASTER UNIV; Like, G [MCMASTER UNIV

    2009-01-01

    By performing heat capacity, magnetocaloric effect, torque magnetometry and force magnetometry measurements up to 33 T, we have mapped out the T-H phase diagram of the S = 1/2 spin dimer compound Ba{sub 3}Cr{sub 2}O{sub 8}. We found evidence for field-induced magnetic order between H{sub cl} = 12.52(2) T and H{sub c2} = 23.65(5) T, with the maximum transition temperature T{sub c} {approx} 2.7 K at H {approx} 18 T. The lower transition can likely be described by Bose-Einstein condensation of triplons theory, and this is consistent with the absence of any magnetization plateaus in our magnetic torque and force measurements. In contrast, the nature of the upper phase transition appears to be quite different as our measurements suggest that this transition is actually first order.

  19. Self-trapped exciton and core-valence luminescence in BaF{sub 2} nanoparticles

    SciTech Connect (OSTI)

    Vistovskyy, V. V. Zhyshkovych, A. V.; Chornodolskyy, Ya. M.; Voloshinovskii, A. S.; Myagkota, O. S.; Gloskovskii, A.; Gektin, A. V.; Vasil'ev, A. N.; Rodnyi, P. A.

    2013-11-21

    The influence of the BaF{sub 2} nanoparticle size on the intensity of the self-trapped exciton luminescence and the radiative core-valence transitions is studied by the luminescence spectroscopy methods using synchrotron radiation. The decrease of the self-trapped exciton emission intensity at energies of exciting photons in the range of optical exciton creation (h? ? E{sub g}) is less sensitive to the reduction of the nanoparticle sizes than in the case of band-to-band excitation, where excitons are formed by the recombination way. The intensity of the core-valence luminescence shows considerably weaker dependence on the nanoparticle sizes in comparison with the intensity of self-trapped exciton luminescence. The revealed regularities are explained by considering the relationship between nanoparticle size and photoelectron or photohole thermalization length as well as the size of electronic excitations.

  20. Investigation of novel decay B _____ ____(2S)____K at BaBar

    SciTech Connect (OSTI)

    Schalch, Jacob; /Oberlin Coll. /SLAC

    2011-06-22

    We investigate the undocumented B meson decay, B{sup +} {yields} {Psi}(2S){omega}K{sup +}. The data were collected with the BaBar detector at the SLAC PEP-II asymmetric-energy e{sup +}e{sup -} collier operating at the {gamma}(4S) resonance, a center-of-mass energy of 10.58 GeV/c{sup 2}. The {gamma}(4S) resonance primarily decays to pairs of B-mesons. The BaBar collaboration at the PEP-II ring was located at the SLAC National Accelerator Laboratory and was designed to study the collisions of positrons and electrons. The e{sup -}e{sup +} pairs collide at asymmetric energies, resulting in a center of mass which is traveling at relativistic speeds. The resulting time dilation allows the decaying particles to travel large distances through the detector before undergoing their rapid decays, a process that occurs in the in the center of mass frame over extremely small distances. As they travel through silicon vertex trackers, a drift chamber, a Cerenkov radiation detector and finally an electromagnetic calorimeter, we measure the charge, energy, momentum, and particle identification in order to reconstruct the decays that have occurred. While all well understood mesons currently fall into the qq model, the quark model has no a priori exclusion of higher configuration states such as qqqq which has led experimentalists and theorists alike to seek evidence supporting the existence of such states. Currently, there are hundreds of known decay modes of the B mesons cataloged by the Particle Data Group, but collectively they only account for approximately 60% of the B branching fraction and it is possible that many more exist.

  1. Source Term Estimates of Radioxenon Released from the BaTek Medical Isotope Production Facility Using External Measured Air Concentrations

    SciTech Connect (OSTI)

    Eslinger, Paul W.; Cameron, Ian M.; Dumais, Johannes R.; Imardjoko, Yudi; Marsoem, Pujadi; McIntyre, Justin I.; Miley, Harry S.; Stoehlker, Ulrich; Widodo, Susilo; Woods, Vincent T.

    2015-10-01

    Abstract Batan Teknologi (BaTek) operates an isotope production facility in Serpong, Indonesia that supplies 99mTc for use in medical procedures. Atmospheric releases of Xe-133 in the production process at BaTek are known to influence the measurements taken at the closest stations of the International Monitoring System (IMS). The purpose of the IMS is to detect evidence of nuclear explosions, including atmospheric releases of radionuclides. The xenon isotopes released from BaTek are the same as those produced in a nuclear explosion, but the isotopic ratios are different. Knowledge of the magnitude of releases from the isotope production facility helps inform analysts trying to decide whether a specific measurement result came from a nuclear explosion. A stack monitor deployed at BaTek in 2013 measured releases to the atmosphere for several isotopes. The facility operates on a weekly cycle, and the stack data for June 15-21, 2013 show a release of 1.84E13 Bq of Xe-133. Concentrations of Xe-133 in the air are available at the same time from a xenon sampler located 14 km from BaTek. An optimization process using atmospheric transport modeling and the sampler air concentrations produced a release estimate of 1.88E13 Bq. The same optimization process yielded a release estimate of 1.70E13 Bq for a different week in 2012. The stack release value and the two optimized estimates are all within 10 percent of each other. Weekly release estimates of 1.8E13 Bq and a 40 percent facility operation rate yields a rough annual release estimate of 3.7E13 Bq of Xe-133. This value is consistent with previously published estimates of annual releases for this facility, which are based on measurements at three IMS stations. These multiple lines of evidence cross-validate the stack release estimates and the release estimates from atmospheric samplers.

  2. Investigations of Ba{sub x}Sr{sub 1?x}TiO{sub 3} ceramics and powders prepared by direct current arc discharge technique

    SciTech Connect (OSTI)

    Li, Shuangbin; Wang, Xiaohan; Yao, Ying Jia, Yongzhong; Xie, Shaolei; Jing, Yan; Yuzyuk, Yu. I.

    2014-09-01

    Ba{sub x}Sr{sub 1?x}TiO{sub 3} ceramics with x ranging from 0 to 1 were prepared by direct current arc discharge technique and studied by means of x-ray diffraction (XRD) and Raman spectroscopy. The cubic-tetragonal ferroelectric phase transition in Ba{sub x}Sr{sub 1?x}TiO{sub 3} ceramics was found to occur at x???0.75. XRD investigation of as-grown BaTiO{sub 3} ceramics revealed co-existence of tetragonal and hexagonal modifications with a small amount of impurity phase BaTi{sub 4}O{sub 9}. No evidences of hexagonal phase were observed in Raman spectra of as-grown BaTiO{sub 3} ceramics, while Raman peaks related to hexagonal phase were clearly observed in the spectrum of fine-grain powders prepared from the same ceramics. A core-shell model for BaTiO{sub 3} ceramics prepared by direct current arc discharge technique is proposed. Absence of the hexagonal phase in any Ba{sub x}Sr{sub 1?x}TiO{sub 3} solid solution with x?

  3. Completion Report for Well ER-16-1 Corrective Action Unit 99: Rainier Mesa - Shoshone Mountain

    SciTech Connect (OSTI)

    NSTec Geology Services

    2006-12-01

    Well ER-16-1 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office, in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. The well was drilled in June and July 2005 as part of a hydrogeologic investigation program for the Rainier Mesa-Shoshone Mountain Corrective Action Unit, Number 99. The overall purpose of the well was to gather subsurface data to better characterize the hydrogeology of the Shoshone Mountain area, especially in the older Tertiary and pre-Tertiary strata. The main 46.99-centimeter hole was drilled to a depth of 702.9 meters and cased with 33.97-centimeter casing to 663.7 meters. The hole diameter was then decreased to 31.1 centimeters, and the well was drilled to total depth of 1,220.7 meters. A completion string set at the depth of 1,162.4 meters consisted of 13.97-centimeter stainless-steel casing, with one continuous slotted interval open to the lower carbonate aquifer. The fluid level in the borehole soon dropped, so the borehole was deepened in July 2006. To deepen the borehole, the slotted section was cemented and a 12.1-centimeter hole was drilled through the bottom of the completion string to the new total depth of 1,391.7 meters, which is 171.0 meters deeper than the original borehole. A string of 6.03-centimeter carbon-steel tubing with one continuous slotted interval at 1,361.8 to 1,381.4 meters, and open to the lower carbonate aquifer, was installed in the well with no gravel packing or cement, to serve as a monitoring string. Data gathered during and shortly after hole construction include composite drill cuttings samples collected every 3 meters (extra cuttings samples were collected from the Paleozoic rocks for paleontological analyses), sidewall core samples from 37 depths, various geophysical logs, and water level measurements. These data indicate that the well penetrated 646.8 meters of Tertiary volcanic rocks and 744.9 meters

  4. A dual chelating solgel synthesis of BaTiO{sub 3} nanoparticles with effective photocatalytic activity for removing humic acid from water

    SciTech Connect (OSTI)

    Wang, Peigong; Fan, Caimei; Wang, Yawen; Ding, Guangyue; Yuan, Peihong

    2013-02-15

    Graphical abstract: The cubic phase BaTiO{sub 3} nanoparticles can be obtained at 600 C and changed into tetragonal phase at 900 C by a dual chelating solgel method, and the photocatalytic activities of the photocatalysts calcined at different temperatures were investigated by the removal of humic acid (HA) from water under UV light irradiation. Highlights: ? The humic acid in water was firstly degradated by BaTiO{sub 3} photocatalyst. ? The cubic BaTiO{sub 3} was obtained and changed into tetragonal phase at lower temperature. ? The chelating agents had an important influence on the phase formation of BaTiO{sub 3}. ? The tetragonal phase BaTiO{sub 3} calcined at 900 C exhibited higher photocatalytic activity under UV irradiation. -- Abstract: In this paper, a dual chelating solgel method was used to synthesize BaTiO{sub 3} nanoparticles by using acetylacetone and citric acid as chelating agents. The samples calcined at different temperatures were analyzed by thermogravimetric and differential thermal analysis (TG-DTA), X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), scanning electron microscope (SEM) and UVvis diffuse reflectance spectra (UVvis). The results indicated that cubic phase BaTiO{sub 3} nanoparticles about 19.6 nm can be obtained at 600 C and changed into tetragonal phase at 900 C about 97.1 nm. All the BaTiO{sub 3} nanoparticles showed effective photocatalytic activities on the removal of humic acid (HA) under UV light irradiation. A comparison of single (acetylacetone or citric acid) and dual chelating (acetylacetone and citric acid) synthetic processes was also studied and the results demonstrated that the dual chelating agents indeed reduced phase transformation temperature from cubic to tetragonal BaTiO{sub 3}.

  5. Negative to positive magnetoresistance and magnetocaloric effect in Pr0.6Er0.4Al2

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Pathak, Arjun K.; Gschneidner, Jr., K. A.; Pecharsky, V. K.

    2014-10-13

    We report on the magnetic, magnetocaloric and magnetotransport properties of Pr0.6Er0.4Al2. The title compound exhibits a large positive magnetoresistance (MR) for H ≥ 40 kOe and a small but non negligible negative MR for H ≤ 30 kOe. The maximum positive MR reaches 13% at H = 80 kOe. The magnetic entropy and adiabatic temperature changes as functions of temperature each show two anomalies: a broad dome-like maximum below 20 K and a relatively sharp peak at higher temperature. As a result, observed behaviors are unique among other binary and mixed lanthanide compounds.

  6. Final Report for DOE grant project FG02-07ER41458 [Dense Quark Matter in Magnetic Fields

    SciTech Connect (OSTI)

    Incera, Vivian

    2012-01-24

    Final Report for DOE grant DE-FG02-07ER41458. This grant was originally a three-year project. However, this final report summarizes the results of the first two years, as at the end of the second year of the grant the PIs moved to a new university and the grant was closed. The work done under the first two years of the DOE grant led to several papers and presentations. It also served to train one undergraduate and three graduate students.

  7. Completion Report for Well ER-20-4 Corrective Action Units 101 and 102: Central and Western Pahute Mesa

    SciTech Connect (OSTI)

    NSTec Environmental Management

    2011-04-30

    Well ER-20-4 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of the Nevada Environmental Restoration Project at the Nevada National Security Site, Nye County, Nevada. The well was drilled in August and September 2010 as part of the Pahute Mesa Phase II drilling program. The primary purpose of the well was to investigate the possibility of radionuclide transport from up-gradient underground nuclear tests conducted in central Pahute Mesa. This well also provided detailed hydrogeologic information in the Tertiary volcanic section that will help reduce uncertainties within the Pahute Mesa-Oasis Valley hydrostratigraphic framework model.

  8. Increased efficiency in multijunction solar cells through the incorporation of semimetallic ErAs nanoparticles into the tunnel junction

    SciTech Connect (OSTI)

    Zide, J.M.O.; Kleiman-Shwarsctein, A.; Strandwitz, N.C.; Zimmerman, J.D.; Steenblock-Smith, T.; Gossard, A.C.; Forman, A.; Ivanovskaya, A.; Stucky, G.D.

    2006-04-17

    We report the molecular beam epitaxy growth of Al{sub 0.3}Ga{sub 0.7}As/GaAs multijunction solar cells with epitaxial, semimetallic ErAs nanoparticles at the interface of the tunnel junction. The states provided by these nanoparticles reduce the bias required to pass current through the tunnel junction by three orders of magnitude, and therefore drastically reduce the voltage losses in the tunnel junction. We have measured open-circuit voltages which are 97% of the sum of the constituent cells, which result in nearly double the efficiency of our multijunction cell with a conventional tunnel junction.

  9. Final Technical Report DOE Award DE-FG02-07ER41515 QUEST Camera Short Term Maintenance

    Office of Scientific and Technical Information (OSTI)

    DOE Award DE-FG02-07ER41515 QUEST Camera Short Term Maintenance PI: Charles Baltay, Yale University The QUEST large area astronomical camera was installed at the prime focus of the Oschin Schmidt Telescope at the Palomar Observatory in California. The camera was used to carry out a survey of low redshift Type 1a supernovae which are the distance indicators used in the measurement of the expansion history of the universe and thus provided a method to study the nature of the recently discovered

  10. Technical support to the ER program subsurface technologies team leader. Final report, March 15, 1993--March 15, 1998

    SciTech Connect (OSTI)

    1998-12-01

    This research included development of a new geologic sample management facility and associated quality assurance systems for the LANL Environmental Restoration Program. Additional work with the LANL Environmental Restoration Program included the development of Sampling and Analysis Plans (SAP) for various Operable Units for the Laboratory. The PI (Davidson) served as the sample curation/sample management specialist on the ER program Subsurface Studies Technical Team. Specialization in Field Unit Data Base systems was the focus of the work towards the end of the contract. A document is included which provides the Statement of Policy for the management of borehole samples collected during environmental restoration activities at LANL.

  11. ABUNDANCES OF C, N, Sr, AND Ba ON THE RED GIANT BRANCH OF {omega} CENTAURI

    SciTech Connect (OSTI)

    Stanford, Laura M.; Da Costa, G. S.; Norris, John E. E-mail: gdc@mso.anu.edu.a

    2010-05-10

    Abundances relative to iron for carbon, nitrogen, strontium, and barium are presented for 33 stars on the red giant branch (RGB) of the globular cluster {omega} Centauri. They are based on intermediate-resolution spectroscopic data covering the blue spectral region analyzed using spectrum synthesis techniques. The data reveal the existence of a broad range in the abundances of these elements, and a comparison with similar data for main-sequence stars enables insight into the evolutionary history of the cluster. The majority of the RGB stars were found to be depleted in carbon, i.e., [C/Fe] < 0, while [N/Fe] for the same stars shows a range of {approx}1 dex, from [N/Fe] {approx} 0.7 to 1.7 dex. The strontium-to-iron abundance ratios varied from solar to mildly enhanced (0.0 {<=} [Sr/Fe] {<=} 0.8), with [Ba/Fe] generally equal to or greater than [Sr/Fe]. The carbon and nitrogen abundance ratios for the one known CH star in the sample, ROA 279, are [C/Fe] = 0.6 and [N/Fe] = 0.5 dex. Evidence for evolutionary mixing on the RGB is found from the fact that the relative carbon abundances on the main sequence are generally higher than those on the RGB. However, comparison of the RGB and main-sequence samples shows that the upper level of nitrogen enhancement is similar in both sets at [N/Fe] {approx} 2.0 dex. This is most likely the result of primordial rather than evolutionary mixing processes. One RGB star, ROA 276, was found to have Sr and Ba abundance ratios similar to the anomalous Sr-rich main-sequence star S2015448. High-resolution spectra of ROA 276 were obtained with the Magellan Telescope/MIKE spectrograph combination to confirm this result, revealing that ROA 276 is indeed an unusual star. For this star, calculations of the depletion effect, the potential change in surface abundance that results from the increased depth of the convective envelope as a star moves from the main sequence to the RGB, strongly suggest that the observed Sr enhancement in ROA 276 is of

  12. FInal Report: DE-FG02-04ER41310 "Elementary Particle Physics"

    SciTech Connect (OSTI)

    Izen, Joseph M.; Ishak-Boushaki, Mustapha

    2013-10-18

    Computing Operations Shifts (ADCoS) During Summer 2012, UTD joined upgrade activities in preparation for LS1. We took a major role in the testing of Electro-Readout (ER) Bundle testing for new Service Quarter Panels (nSQP?s), and we developed two utilities to measure the timing jitter and bit error rate of the Pixel readout chain for use commissioning Pixel detector upgrades. During BABAR?s heyday, the UTD group pioneered the use of e^+ e^- annihilation events with hard Initial State Radiation (ISR) to study the charm threshold region, and we carried out the first BABAR double-cc analysis. Our most recent ISR paper, written in collaboration with A. Palano (Bari) is Exclusive Production of Ds^+ Ds^-, D_S^(*+) Ds^-, and Ds^(*+) Ds^(*-) via e+ e- Annihilation with Initial-State-Radiation was published in Physical Review D 82, 052004 (2010). Work continues on a study of ISR Λc^+ Λc^- production, and a new search to establish and study double-ss production is starting.

  13. Two-dimensional resonant magnetic excitation in BaFe1.84Co0.16As2

    SciTech Connect (OSTI)

    Lumsden, Mark D; Christianson, Andrew D; Parshall, Daniel; Stone, Matthew B; Nagler, Stephen E; Mook Jr, Herbert A; Lokshin, Konstantin A; Egami, Takeshi; Abernathy, Douglas L; Goremychkin, E. A.; Osborn, R.; McGuire, Michael A; Safa-Sefat, Athena; Jin, Rongying; Sales, Brian C; Mandrus, David

    2009-01-01

    Inelastic neutron scattering measurements on single crystals of superconducting BaFe1.84Co0.16As2 clearly reveal a magnetic excitation located at wavevectors (1/2 1/2 L) in tetragonal notation. The scattering is much broader in L than are spin waves observed in the parent compound BaFe2As2 indicating that the excitations in the superconducting material are more two-dimensional in nature. The excitation appears gapless for T > TC and becomes gapped on cooling below TC. The observed gap energy is approximately 9.6 meV corresponding to 5 kBTC which is remarkably similar to the canonical value for the resonance energy in the cuprates.

  14. Temperature and composition phase diagram in the iron-based ladder compounds Ba 1 - x Cs x Fe 2 Se 3

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hawai, Takafumi; Nambu, Yusuke; Ohgushi, Kenya; Du, Fei; Hirata, Yasuyuki; Avdeev, Maxim; Uwatoko, Yoshiya; Sekine, Yurina; Fukazawa, Hiroshi; Ma, Jie; et al

    2015-05-28

    We investigated the iron-based ladder compounds (Ba,Cs)Fe₂Se₃. Their parent compounds BaFe₂Se₃ and CsFe₂Se₃ have different space groups, formal valences of Fe, and magnetic structures. Electrical resistivity, specific heat, magnetic susceptibility, x-ray diffraction, and powder neutron diffraction measurements were conducted to obtain a temperature and composition phase diagram of this system. Block magnetism observed in BaFe₂Se₃ is drastically suppressed with Cs doping. In contrast, stripe magnetism observed in CsFe₂Se₃ is not so fragile against Ba doping. A new type of magnetic structure appears in intermediate compositions, which is similar to stripe magnetism of CsFe₂Se₃, but interladder spin configuration is different. Intermediatemore » compounds show insulating behavior, nevertheless a finite T-linear contribution in specific heat was obtained at low temperatures.« less

  15. Data:0a710392-0262-4cde-a5ba-d1dd41e15527 | Open Energy Information

    Open Energy Info (EERE)

    cde-a5ba-d1dd41e15527 No revision has been approved for this page. It is currently under review by our subject matter experts. Jump to: navigation, search Loading... 1. Basic...

  16. Completion Report for Well ER-EC-14, Corrective Action Units 101 and 102: Central and Western Pahute Mesa

    SciTech Connect (OSTI)

    2013-03-05

    Well ER-EC-14 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of the Nevada Environmental Management Operations Underground Test Area (UGTA) Activity at the Nevada National Security Site (NNSS; formerly Nevada Test Site), Nye County, Nevada. The well was drilled in September and October 2012, as part of the Central and Western Pahute Mesa Corrective Action Unit Phase II drilling program. The primary purpose of the well was to provide detailed hydrogeologic information for the Fortymile Canyon composite hydrostratigraphic unit in the Timber Mountain moat area, within the Timber Mountain caldera complex, that will help address uncertainties within the Pahute Mesa–Oasis Valley hydrostratigraphic framework model. The main 55.9-centimeter (cm) hole was drilled to a total depth of 325.5 meters (m) and cased with 40.6-cm casing to 308.1 m. The hole diameter was then decreased to 37.5 cm, and drilling continued to a total depth of 724.8 m. The completion casing string, set to the depth of 690.9 m, consists of 16.8-cm stainless-steel casing hanging from 19.4-cm carbon-steel casing. The stainless-steel casing has two slotted intervals open to the Rainier Mesa Tuff. Two piezometer strings were installed in Well ER-EC-14. Both piezometer strings, each with one slotted interval, consist of 6.0-cm carbon-steel tubing at the surface, then cross over to 7.3-cm stainless-steel tubing just above the water table. The shallow piezometer string was landed at 507.8 m, and the deep piezometer string was landed at 688.6 m. Both piezometer strings are set to monitor groundwater within moderately to densely welded Rainier Mesa Tuff. Data collected during and shortly after hole construction include composite drill cuttings samples collected every 3.0 m, various geophysical logs, water quality (including tritium and other radionuclides) measurements, and water level measurements. The well penetrated 15.2 m of alluvium and

  17. Synthesis, Crystal and Electronic Structures of the Pnictides AE3TrPn3 (AE = Sr, Ba; Tr = Al, Ga; Pn = P, As)

    SciTech Connect (OSTI)

    Stoyko, Stanislav; Voss, Leonard; He, Hua; Bobev, Svilen

    2015-09-24

    New ternary arsenides AE3TrAs3 (AE = Sr, Ba; Tr = Al, Ga) and their phosphide analogs Sr3GaP3 and Ba3AlP3 have been prepared by reactions of the respective elements at high temperatures. Single-crystal X-ray diffraction studies reveal that Sr3AlAs3 and Ba3AlAs3 adopt the Ba3AlSb3-type structure (Pearson symbol oC56, space group Cmce, Z = 8). This structure is also realized for Sr3GaP3 and Ba3AlP3. Likewise, the compounds Sr3GaAs3 and Ba3GaAs3 crystallize with the Ba3GaSb3-type structure (Pearson symbol oP56, space group Pnma, Z = 8). Both structures are made up of isolated pairs of edge-shared AlPn4 and GaPn4 tetrahedra (Pn = pnictogen, i.e., P or As), separated by the alkaline-earth Sr2+ and Ba2+ cations. In both cases, there are no homoatomic bonds, hence, regardless of the slightly different atomic arrangements, both structures can be rationalized as valence-precise [AE2+]3[Tr3+][Pn3-]3, or rather [AE2+]6[Tr2Pn6]12-, i.e., as Zintl phases.

  18. Electric control of magnetism at the Fe/BaTiO3 interface

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Radaelli, G.; Petti, D.; Plekhanov, E.; Fina, I.; Torelli, P.; Salles, B. R.; Cantoni, M.; Rinaldi, C.; Gutiérrez, D.; Panaccione, G.; et al

    2014-03-03

    Interfacial magnetoelectric coupling (MEC) is a viable path to achieve electrical writing of magnetic information in spintronic devices. For the prototypical Fe/BaTiO3 (BTO) system, only tiny changes of the interfacial Fe magnetic moment upon reversal of the BTO dielectric polarization have been predicted so far. Here, by using X-ray magnetic circular dichroism in combination with high resolution electron microscopy and first principles calculations, we report on an undisclosed physical mechanism for interfacial MEC in the Fe/BTO system. At the Fe/BTO interface, an ultrathin FeOx layer exists, whose magnetization can be electrically and reversibly switched on-off at room-temperature by reversing themore » BTO polarization. The suppression / recovery of interfacial ferromagnetism results from the asymmetric effect that ionic displacements in BTO produces on the exchange coupling constants in the adjacent FeOx layer. The observed giant magnetoelectric response holds potential for optimizing interfacial MEC in view of efficient, low-power spintronic devices.« less

  19. Structural and optical study of ? BIMEVOX; ME: Ba{sup 2+} and Sr{sup 2+}

    SciTech Connect (OSTI)

    Gupta, Sakshi Singh, K.

    2015-05-15

    Bismuth oxide based compounds, such as Bi{sub 4}V{sub 2}O{sub 11-?} (BIVOX), exhibit Aurivillus type of interleaving arrangement of (Bi{sub 2}O{sub 2}){sup 2+} and (VO{sub 3}?{sub 0.5}){sup 2-} (?: oxygen vacancies). Bi{sub 4}V{sub 2}O{sub 11-?,} is known to have three kinds of temperature dependent interconvertible polymorphs ? (monoclinic), ? (orthorhombic) and ? (tetragonal). Out of all the three phases, the ? phase is highly disordered and hence, is the most conductive one which can be stabilized by proper lower valence cation (ME) doping at V site. Bi{sub 4}V{sub 1.90}ME{sub 0.20}O{sub 11-?} (ME: Ba{sup 2+} and Sr{sup 2+}) were prepared via splat quenching technique. The required compositions were melted at 1250 C in an electric furnace. The as quenched samples were sintered at 800 C for 12 hours (h). The formed phases were analyzed using X-ray diffraction on quenched and sintered samples, the peak at 32{sup } is found to be singlet in all the samples which confirms the presence of ?-phase. Hence, the stabilization of ?-phase with tetragonal structure was found to have taken place with doping and quenching. These samples are also studied by FT-IR and UV/vis spectroscopy to investigate the effect of dopants on structure and band gaps respectively.

  20. High temperature superconductor step-edge Josephson junctions using Ti-Ca-Ba-Cu-O

    DOE Patents [OSTI]

    Ginley, David S.; Hietala, Vincent M.; Hohenwarter, Gert K. G.; Martens, Jon S.; Plut, Thomas A.; Tigges, Chris P.; Vawter, Gregory A.; Zipperian, Thomas E.

    1994-10-25

    A process for formulating non-hysteretic and hysteretic Josephson junctions using HTS materials which results in junctions having the ability to operate at high temperatures while maintaining high uniformity and quality. The non-hysteretic Josephson junction is formed by step-etching a LaAlO.sub.3 crystal substrate and then depositing a thin film of TlCaBaCuO on the substrate, covering the step, and forming a grain boundary at the step and a subsequent Josephson junction. Once the non-hysteretic junction is formed the next step to form the hysteretic Josephson junction is to add capacitance to the system. In the current embodiment, this is accomplished by adding a thin dielectric layer, LaA1O.sub.3, followed by a cap layer of a normal metal where the cap layer is formed by first depositing a thin layer of titanium (Ti) followed by a layer of gold (Au). The dielectric layer and the normal metal cap are patterned to the desired geometry.

  1. New insulating antiferromagnetic quaternary iridates MLa10Ir4O24 (M=Sr, Ba)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    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, Jeff = ½, that defines the electronic and magnetic properties. The canonical example is the Ruddlesden-Popper compound Sr2IrO4, which has been suggested as a potential route to a new class of high temperature superconductor due to the formal analogy between Jeff = 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. Inmore » this spirit, here we report the synthesis and physical properties of two new quaternary tetravalent iridates, MLa10Ir4O24 (M = Sr, Ba). The crystal structure of both compounds features isolated IrO6 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 SrLa10Ir4O24 is an insulator.« less

  2. Structural feature controlling superconductivity in compressed BaFe{sub 2}As{sub 2}

    SciTech Connect (OSTI)

    Yang, Wenge; Jia, Feng-Jiang; Tang, Ling-Yun; Tao, Qian; Xu, Zhu-An; Chen, Xiao-Jia

    2014-02-28

    Superconductivity can be induced with the application of pressure but it disappears eventually upon heavy compression in the iron-based parent compound BaFe{sub 2}As{sub 2}. Structural evolution with pressure is used to understand this behavior. By performing synchrotron X-ray powder diffraction measurements with diamond anvil cells up to 26.1 GPa, we find an anomalous behavior of the lattice parameter with a S shape along the a axis but a monotonic decrease in the c-axis lattice parameter with increasing pressure. The close relationship between the axial ratio c/a and the superconducting transition temperature T{sub c} is established for this parent compound. The c/a ratio is suggested to be a measure of the spin fluctuation strength. The reduction of T{sub c} with the further increase of pressure is a result of the pressure-driven weakness of the spin-fluctuation strength in this material.

  3. High temperature superconductor step-edge Josephson junctions using Ti-Ca-Ba-Cu-O

    DOE Patents [OSTI]

    Ginley, D.S.; Hietala, V.M.; Hohenwarter, G.K.G.; Martens, J.S.; Plut, T.A.; Tigges, C.P.; Vawter, G.A.; Zipperian, T.E.

    1994-10-25

    A process is disclosed for formulating non-hysteretic and hysteretic Josephson junctions using HTS materials which results in junctions having the ability to operate at high temperatures while maintaining high uniformity and quality. The non-hysteretic Josephson junction is formed by step-etching a LaAlO[sub 3] crystal substrate and then depositing a thin film of TlCaBaCuO on the substrate, covering the step, and forming a grain boundary at the step and a subsequent Josephson junction. Once the non-hysteretic junction is formed the next step to form the hysteretic Josephson junction is to add capacitance to the system. In the current embodiment, this is accomplished by adding a thin dielectric layer, LaA1O[sub 3], followed by a cap layer of a normal metal where the cap layer is formed by first depositing a thin layer of titanium (Ti) followed by a layer of gold (Au). The dielectric layer and the normal metal cap are patterned to the desired geometry. 8 figs.

  4. Ba2+-inhibitable /sup 86/Rb+ fluxes across membranes of vesicles from toad urinary bladder

    SciTech Connect (OSTI)

    Garty, H.; Civan, M.M.

    1987-01-01

    /sup 86/Rb+ fluxes have been measured in suspensions of vesicles prepared from the epithelium of toad urinary bladder. A readily measurable barium-sensitive, ouabain-insensitive component has been identified; the concentration of external Ba2+ required for half-maximal inhibition was 0.6 mM. The effects of externally added cations on /sup 86/Rb+ influx and efflux have established that this pathway is conductive, with a selectivity for K+, Rb+ and Cs+ over Na+ and Li+. The Rb+ uptake is inversely dependent on external pH, but not significantly affected by internal Ca2+ or external amiloride, quinine, quinidine or lidocaine. It is likely, albeit not yet certain, that the conductive Rb+ pathway is incorporated in basolateral vesicles oriented right-side-out. It is also not yet clear whether this pathway comprises the principle basolateral K+ channel in vivo, and that its properties have been unchanged during the preparative procedures. Subject to these caveats, the data suggest that the inhibition by quinidine of Na+ transport across toad bladder does not arise primarily from membrane depolarization produced by a direct blockage of the basolateral channels. It now seems more likely that the quinidine-induced elevation of intracellular Ca2+ activity directly blocks apical Na+ entry.

  5. High field nuclear magnetic resonance in transition metal substituted BaFe{sub 2}As{sub 2}

    SciTech Connect (OSTI)

    Garitezi, T. M. Lesseux, G. G.; Rosa, P. F. S.; Adriano, C.; Pagliuso, P. G.; Urbano, R. R.; Reyes, A. P.; Kuhns, P. L.

    2014-05-07

    We report high field {sup 75}As nuclear magnetic resonance (NMR) measurements on Co and Cu substituted BaFe{sub 2}As{sub 2} single crystals displaying same structural/magnetic transition T{sub 0}≃128  K. From our anisotropy studies in the paramagnetic state, we strikingly found virtually identical quadrupolar splitting and consequently the quadrupole frequency ν{sub Q}≃2.57(1)  MHz for both compounds, despite the claim that each Cu delivers 2 extra 3d electrons in BaFe{sub 2}As{sub 2} compared to Co substitution. These results allow us to conclude that a subtle change in the crystallographic structure, particularly in the Fe–As tetrahedra, must be the most probable tuning parameter to determine T{sub 0} in this class of superconductors rather than electronic doping. Furthermore, our NMR data around T{sub 0} suggest coexistence of tetragonal/paramagnetic and orthorhombic/antiferromagnetic phases between the structural and the spin density wave magnetic phase transitions, similarly to what was reported for K-doped BaFe{sub 2}As{sub 2} [Urbano et al., Phys. Rev. Lett. 105, 107001 (2010)].

  6. Anomalous magneto-elastic and charge doping effects in thallium-doped BaFe2As2

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Sefat, Athena S.; Li, Li; Cao, Huibo B.; McGuire, Michael A.; Sales, Brian; Custelcean, Radu; Parker, David S.

    2016-02-12

    Within the BaFe2As2 crystal lattice, we partially substitute thallium for barium and report the effects of interlayer coupling in Ba1-xTlxFe2As2 crystals. We demonstrate the unusual effects of magneto-elastic coupling and charge doping in this iron-arsenide material, whereby Néel temperature rises with small x, and then falls with additional x. Specifically, we find that Néel and structural transitions in BaFe2As2 (TN = Ts = 133 K) increase for x = 0.05 (TN = 138 K, Ts = 140 K) from magnetization, heat capacity, resistivity, and neutron diffraction measurements. Evidence from single crystal X-ray diffraction and first principles calculations attributes the stronger magnetism in x = 0.05 to magneto-elastic coupling related to the shorter intraplanar Fe-Fe bondmore » distance. With further thallium substitution, the transition temperatures decrease for x = 0.09 (TN = Ts = 131 K), and this is due to charge doping. Finally, we illustrate that small changes related to 3d transition-metal state can have profound effects on magnetism.« less

  7. Structural and magnetic properties of the Kagome antiferromagnet YbBaCo{sub 4}O{sub 7}

    SciTech Connect (OSTI)

    Huq, A.; Mitchell, J.F. . E-mail: mitchell@anl.gov; Zheng, H.; Chapon, L.C.; Radaelli, P.G.; Knight, K.S.; Stephens, P.W.

    2006-04-15

    The mixed-valent compound YbBaCo{sub 4}O{sub 7} is built up of Kagome sheets of CoO{sub 4} tetrahedra, linked in the third dimension by a triangular layer of CoO{sub 4} tetrahedra in an analogous fashion to that found in the known geometrically frustrated magnets such as pyrochlores and SrCr{sub 9} {sub x} Ga{sub 12-9} {sub x} O{sub 19} (SCGO). We have undertaken a study of the structural and magnetic properties of this compound using combined high-resolution powder neutron and synchrotron X-ray diffraction. YbBaCo{sub 4}O{sub 7} undergoes a first-order trigonal{sup {yields}}orthorhombic phase transition at 175 K. We show that this transition occurs as a response to a markedly underbonded Ba{sup 2+} site in the high-temperature phase and does not appear to involve charge ordering of Co{sup 2+}/Co{sup 3+} ions in the tetrahedra. The symmetry lowering relieves the geometric frustration of the structure, and a long-range-ordered 3-D antiferromagnetic state develops below 80 K.

  8. Structural and magnetic phase transitions near optimal superconductivity in BaFe2(As1-xPx)2

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hu, Ding; Lu, Xingye; Zhang, Wenliang; Luo, Huiqian; Li, Shiliang; Wang, Peipei; Chen, Genfu; Han, Fei; Banjara, Shree R.; Sapkota, A.; et al

    2015-04-17

    In this study, we use nuclear magnetic resonance (NMR), high-resolution x-ray and neutron scattering to study structural and magnetic phase transitions in phosphorus-doped BaFe2(As1-xPx)2. Thus, previous transport, NMR, specific heat, and magnetic penetration depth measurements have provided compelling evidence for the presence of a quantum critical point (QCP) near optimal superconductivity at x = 0.3. However, we show that the tetragonal-to-orthorhombic structural (Ts) and paramagnetic to antiferromagnetic (AF, TN) transitions in BaFe2(As1-xPx)2 are always coupled and approach to TN ≈ Ts ≥ Tc (≈ 29 K) for x = 0.29 before vanishing abruptly for x ≥ 0.3. These results suggestmore » that AF order in BaFe2(As1-xPx)2 disappears in a weakly first order fashion near optimal superconductivity, much like the electron-doped iron pnictides with an avoided QCP.« less

  9. Structure and magnetic properties of Ba{sub 5}Ce{sub 1.25}Mn{sub 3.75}O{sub 15}, a new 10H-polytype in the Ba-Ce-Mn-O system

    SciTech Connect (OSTI)

    Macias, Mario A.; Mentre, Olivier; Cuello, Gabriel J.; Gauthier, Gilles H.

    2013-02-15

    Based on the peculiar magnetic properties that are observed in pseudo one-dimensional manganites, we decided to synthesize the new Ba{sub 5}Ce{sub 1.25}Mn{sub 3.75}O{sub 15} compound. The preparation was performed by solid state reaction in air at about 1350 Degree-Sign C, for which we found that the compound crystallizes in a hexagonal symmetry with space group P6{sub 3}/mmc (No-194) and cell parameters a=b=5.7861(2) A and c=23.902(1) A. The structural description was correlated with neutron diffraction and bond valence calculations, confirming the presence of Ce{sup 4+} and Mn{sup 4+} segregated in the different crystallographic positions. Ba{sub 5}Ce{sub 1.25}Mn{sub 3.75}O{sub 15} displays evidence for strong AFM couplings already set at room temperature. The main arrangement of Mn{sup 4+} in magnetically isolated tetramers of face-sharing octahedra is responsible for a metamagnetic-like transition around 50 K. - Graphical abstract: The new Ba{sub 5}Ce{sub 1.25}Mn{sub 3.75}O{sub 15} polytype shows strong AFM couplings in magnetically isolated [Ce{sub 0.25}Mn{sub 3.75}O{sub 15}] tetramers of face-sharing octahedral, resulting in a metamagnetic-like transition around 50 K. Highlights: Black-Right-Pointing-Pointer Ba{sub 5}Ce{sub 1.25}Mn{sub 3.75}O{sub 15}, a new 10H polytype, has been prepared in the Ba-Ce-Mn-O system. Black-Right-Pointing-Pointer The compound crystallizes in the P6{sub 3}/mmc space group with (cchhh){sub 2} stacking sequence. Black-Right-Pointing-Pointer [Ce{sub 0.25}Mn{sub 3.75}O{sub 15}] tetramers are separated by [CeO{sub 6}] octahedra in the structure. Black-Right-Pointing-Pointer Instead of robust AFM ordering, a metamagnetic-like transition is found around 50 K.

  10. Antiferromagnetic transitions of osmium-containing rare earth double perovskites Ba{sub 2}LnOsO{sub 6} (Ln=rare earths)

    SciTech Connect (OSTI)

    Hinatsu, Yukio Doi, Yoshihiro; Wakeshima, Makoto

    2013-10-15

    The perovskite-type compounds containing both rare earth and osmium Ba{sub 2}LnOsO{sub 6} (Ln=Pr, Nd, SmLu) have been prepared. Powder X-ray diffraction measurements and Rietveld analysis show that Ln{sup 3+} and Os{sup 5+} ions are structurally ordered at the M site of the perovskite BaMO{sub 3}. Magnetic susceptibility and specific heat measurements show that an antiferromagnetic ordering of Os{sup 5+} ions has been observed for Ba{sub 2}LnOsO{sub 6} (Ln=Pr, Nd, Sm, Eu, Gd, Lu) at 6571 K. Magnetic ordering of Ln{sup 3+} moments occurs when the temperature is furthermore decreased. - Graphical abstract: The perovskite-type compounds containing both rare earth and osmium Ba{sub 2}LnOsO{sub 6} (Ln=Pr, Nd, SmLu) have been prepared. An antiferromagnetic ordering of Os{sup 5+} ions has been observed for Ba{sub 2}LnOsO{sub 6} (Ln=Pr, Nd, Sm, Eu, Gd, Lu) at 6571 K. Measurements and analysis of the specific heat for Ba{sub 2}PrOsO{sub 6} show that magnetic ordering of the Pr{sup 3+} moments should have occurred at ?20 K. Display Omitted.

  11. 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.

  12. In-situ time-of-flight neutron diffraction of ErD2 (beta phase) formation during D2 loading.

    SciTech Connect (OSTI)

    Browning, James Frederick; Llobet, Anna; Snow, Clark Sheldon; Rodriguez, Mark Andrew; Wixom, Ryan R.

    2008-06-01

    In an effort to better understand the structural changes occurring during hydrogen loading of erbium target materials, we have performed D{sub 2} loading of erbium metal (powder) with simultaneous neutron diffraction analysis. This experiment tracked the conversion of Er metal to the {alpha} erbium deuteride (solid-solution) phase and then on to the {beta} (fluorite) phase. Complete conversion to ErD{sub 2.0} was accomplished at 10 Torr D{sub 2} pressure with deuterium fully occupying the tetrahedral sites in the fluorite lattice. Increased D{sub 2} pressure (up to 500 Torr at 450 C) revealed {approx}10 % deuterium occupation of the octahedral sites. Subsequent vacuum pumping of the sample at 450 C removed octahedral site occupancy while maintaining tetrahedral deuterium occupancy, thereby yielding stoichiometric ErD{sub 2.0} {beta} phase.

  13. Magnetic properties and magnetocaloric effects of Gd{sub x}Er{sub 1−x}Ga (0 ≤ x ≤ 1) compounds

    SciTech Connect (OSTI)

    Zheng, X. Q.; Wang, L. C.; Wu, R. R.; Hu, F. X.; Sun, J. R.; Shen, B. G.; Chen, J.

    2014-05-07

    We carefully studied the magnetic properties and magnetocaloric effect of Gd{sub x}Er{sub 1-x}Ga (0 ≤ x ≤ 1) compounds. The Gd{sub x}Er{sub 1-x}Ga compounds undergo two magnetic transitions with temperature increasing: spin-reorientation or antiferromagnetic-to-ferromagnetic (FM) transition and FM-to-paramagnetic transition. As the content of Gd increases from 0 to 1, the transition temperature in low temperature region changes from 15 K to 66 K and the Curie temperature increases obviously from 30 K to 181.9 K. Although the maximum value of magnetic entropy change (ΔS{sub M}) for Gd{sub x}Er{sub 1−x}Ga decreases with the increase of x, the refrigerant capacity (RC) improves remarkably compared with that of ErGa compound. Table-like ΔS{sub M} curves are observed for the compounds with x = 0.1, 0.2, 0.3, and 0.4, which are very useful for real cooling applications. And Gd{sub 0.2}Er{sub 0.8}Ga and Gd{sub 0.3}Er{sub 0.7}Ga compounds show better magnetocaloric features than others in this series under considerations of both ΔS{sub M} and RC. The results of this series of compounds show us a possible way to design and improve the magnetic refrigerant materials by making some substitutions.

  14. DE-FG02-08ER64658 (OASIS) - Final Technical Report

    SciTech Connect (OSTI)

    Sharman, Jonathan

    2013-09-05

    Project OASIS (Operation of Advanced Structures, Interfaces and Sub-components for MEAs) was a 12 month project that ran from 1st September 2008 to 31st August 2009, and was managed by the Department of Energy Office of Science, Chicago Office, as Award No DE-FG02-08ER64658, with Johnson Matthey Fuel Cells Inc. as the sole contractor. The project was completed on schedule, with technical successes (details below) and payment of the full grant award made by DOE. The aim of the project was the development of membrane electrode assemblies (MEAs) for H2/air polymer electrolyte membrane (PEM) fuel cells that would give higher performance under hot/dry and dry operating conditions, ideally with no loss of performance under wet conditions. Reducing or eliminating the need for humidifying the incoming gases will allow significant system cost and size reduction for many fuel cell applications including automotive, stationary and back-up power, and portable systems. Portable systems are also of particular interest in military markets. In previous work Johnson Matthey Fuel Cells had developed very stable, corrosion-resistant catalysts suitable for resisting degradation by carbon corrosion in particular. These materials were applied within the OASIS project as they are considered necessary for systems such as automotive where multiple start-stop events are experienced. These catalysts were contrasted with more conventional materials in the design of catalyst layers and novel microporous layers (MPLs) and gas diffusion layer (GDL) combinations were also explored. Early on in the work it was shown how much more aggressive high temperature operation is than dry operation. At the same humidity, tests at 110?C caused much more dehydration than tests at 80?C and the high temperature condition was much more revealing of improvements made to MEA design. Alloy catalysts were introduced and compared with Pt catalysts with a range of particle sizes. It was apparent that the larger

  15. CHARGE-IMBALANCE RELAXATION IN THE PRESENCE OF A PAIR-BREAKING INTERACTION IN SUPERCONDUCTING AlEr FILMS

    SciTech Connect (OSTI)

    Lemberger, T.R.; Clarke, J.

    1980-07-01

    The charge-imbalance relaxation rate, 1/F*{sub T{sub Q*}}, has been measured in dirty superconducting AlEr films in which Er is a pair-breaking magnetic impurity that induces charge relaxation through elastic exchange scattering. Measurements were made in the range 0.1 {approx}< {Delta}(T)/k{sub B}T{sub c} {approx}< 1.4 for Er concentrations varying from 21 to 1660 at. ppm that produced estimated exchange scattering rates, {tau}{sub S}{sup -1}, from about 10{sup 9} sec{sup -1} to 5 x 10{sup 10} sec{sup -1}. Measured values of 1/F*{sub T{sub Q*}} were in good agreement with the Schmid-Schoen expression, 1/F*{sub T{sub Q*}}=({pi}{Delta}/4k{sub B}T{sub c}{tau}{sub E}) x (1+2{tau}{sub E}/{tau}{sub S}){sup 1/2}, for {Delta}/k{sub B}T{sub c} {approx}< 0.8, where {tau}{sub E}{sup -1} is the electron-phonon scattering rate estimated from the measured transition temperature. For larger values of {Delta}/k{sub B}T{sub c}, the relaxation rate increased less rapidly with {Delta}. The appropriate Boltzmann equation was solved on a computer to obtain values for 1/F*{sub T{sub Q*}} in the range 0.5 {approx}< T/T{sub c} {approx}< 0.999999. The computed values of 1/F*{sub T{sub Q*}} agreed with several analytic expressions valid for {Delta}/k{sub B}T{sub c} << 1, but not with the experimental data: The computed curves increased more rapidly than linearly with {Delta}/k{sub B}T{sub c} near T{sub c}, and the shape of the 1/F*{sub T{sub Q*}} vs {Delta}/k{sub B}T{sub c} curves was qualitatively different. This discrepancy suggests that either the generally accepted expression for exchange charge relaxation is incorrect, or that the Boltzmann equation is inappropriate for these calculations.

  16. Mixed metallic Ba(Co,Mn)X{sub 0.2-x}O{sub 3-{delta}} (X=F, Cl) hexagonal perovskites

    SciTech Connect (OSTI)

    Iorgulescu, Mihaela; Roussel, Pascal; Tancret, Nathalie; Renaut, Nicolas; Tiercelin, Nicolas; Mentre, Olivier

    2013-02-15

    We show here that the incorporation of Mn in Ba-Co-oxohalide, BaCoX{sub 0.2-x}O{sub 3-{delta}}, hexagonal perovskite stabilizes the 6H-form (stacking sequence (chhhch Prime ); c, h=[BaO{sub 3}] and h Prime =[BaOX] layers), with tetramers of face-sharing octahedra) rather than the trimeric 10H-form. On the contrary to previous results on the Fe incorporation in similar system leading to more reduced 10H-compounds, the Mn effect is to increase the mean (Co/Mn) valence better suited to the 6H form. We experienced a poor Mn/Co miscibility during our syntheses leading to great difficulties to isolate mixed Co/Mn single phase materials and/or weak reproducibility. Powder neutron diffraction data shows a mixed Mn/Co octahedral occupancy, while the tetrahedra are filled by Co{sup 3+} cations. Anionic vacancies were refined in the h Prime -[BaO{sub 1-z}X{sub 1-x}] layer and the next c-[BaO{sub 3-z}] layers, while the h-[BaO{sub 3}] layers are not oxygen deficient. Magnetic properties suggest that a part of Mn cations remain paramagnetic until low temperature, while isolated spin clusters (probably driven by AFM Co tetrahedral dimers) behave as low-dimensional AFM systems. Transport measurements reveal a transition from high-temperature metallic to low-temperature semi-conducting states that could occur from defect shallow donor upon the Mn for Co substitution. - Graphical abstract: The incorporation of Mn in Ba-Co-oxohalide, BaCoX{sub 0.2-x}O{sub 3-{delta}}, hexagonal perovskite stabilizes the 6H-form with tetrameric (Co,Mn){sub 4}O{sub 15} face sharing linear chains. This results from a oxidizing Mn effect and particular Mn/Co distribution. Highlights: Black-Right-Pointing-Pointer The incorporation of Mn in BaCoX{sub 0.2-x}O{sub 3-{delta}} (X=F,Cl) hexagonal perovskites stabilizes the 6H-form. Black-Right-Pointing-Pointer It contains tetrameric (Co,Mn){sub 4}O{sub 15} face sharing linear chains. Black-Right-Pointing-Pointer The preference for such chains better than

  17. Exploring the electronic structure and optical properties of the quaternary selenide compound, Ba{sub 4}Ga{sub 4}SnSe{sub 12}: For photovoltaic applications

    SciTech Connect (OSTI)

    Azam, Sikander; Khan, Saleem Ayaz; Goumri-Said, Souraya

    2015-09-15

    Due to huge demand on discovering new materials for energy, we used first-principle calculations to explore the electronic structure and optical properties of a recent quaternary selenide, namely Ba{sub 4}Ga{sub 4}SnSe{sub 12}. The electronic structure and the optical properties of Ba{sub 4}Ga{sub 4}SnSe{sub 12} were calculated through a reliable approach of Engle Vosko-GGA (EV-GGA). We found that Ba{sub 4}Ga{sub 4}SnSe{sub 12} has a direct band gap of 2.14 eV positioned at Γ. Acquiring the fundamental characteristics of Ba{sub 4}Ga{sub 4}SnSe{sub 12,} we studied the linear optical properties like dielectric function in the energy range of 0–14 eV. From the dielectric function we noticed a weak directional anisotropy for the two components. The absorption spectrum indicates the possibility of greater multiple direct and indirect inter-band transitions in the visible regions and shows similar behavior with experimental spectrum. Ba{sub 4}Ga{sub 4}SnSe{sub 12} can be used as shielding material from UV radiations. Present study predicts that the Ba{sub 4}Ga{sub 4}SnSe{sub 12} is promising for photovoltaic applications due to their high absorption of solar radiations and photoconductivity in the visible range. - Graphical abstract: Interesting quaternary selenide compound, Ba{sub 4}Ga{sub 4}SnSe{sub 12}, for photovoltaic applications. - Highlights: • Ba{sub 4}Ga{sub 4}SnSe{sub 12} is a quaternary selenide designed for PV and thermoelectric. • Ba{sub 4}Ga{sub 4}SnSe{sub 12} has a direct band gap of 2.14 eV. • Ba{sub 4}Ga{sub 4}SnSe{sub 12,} has a maximum reflectivity in the visible and UV regions.

  18. Diffuse magnetic neutron scattering in the highly frustrated double perovskite Ba2YRuO6

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Nilsen, Gøran. J.; Thompson, Corey M.; Ehlers, Georg; Marjerrison, Casey A.; Greedan, John E.

    2015-02-23

    Here we investigated diffuse magnetic scattering in the highly frustrated double perovskite Ba2YRuO6 using polarized neutrons. Consistent with previous reports, the material shows two apparent transitions at 47 and 36 K to an eventual type I face-centered-cubic magnetic ground state. The (100) magnetic reflection shows different behavior from the five other observed reflections upon heating from 1.8 K, with the former broadening well beyond the resolution limit near 36 K. Closer examination of the latter group reveals a small, but clear, increase in peak widths between 36 and 47 K, indicating that this regime is dominated by short-range spin correlations.more » Diffuse magnetic scattering persists above 47 K near the position of (100) to at least 200 K, consistent with strong frustration. Reverse Monte Carlo (RMC) modeling of the diffuse scattering from 45 to 200 K finds that the spin-spin correlations between nearest and next-nearest neighbors are antiferromagnetic and ferromagnetic, respectively, at temperatures near the upper ordering temperature, but both become antiferromagnetic and of similar magnitude above 100 K. The significance of this unusual crossover is discussed in light of the super-superexchange interactions between nearest and next-nearest neighbors in this material and the demands of type I order. The dimensionality of the correlations is addressed by reconstructing the scattering in the (hk0) plane using the RMC spin configurations. This indicates that one-dimensional spin correlations dominate at temperatures close to the first transition. In addition, a comparison between mean-field calculations and (hk0) scattering implies that further neighbor couplings play a significant role in the selection of the ground state. Finally, the results and interpretation are compared with those recently published for monoclinic Sr2YRuO6, and similarities and differences are emphasized.« less

  19. Relativistic energy density functionals: Low-energy collective states of {sup 240}Pu and {sup 166}Er

    SciTech Connect (OSTI)

    Li, Z. P.; Niksic, T.; Vretenar, D.; Ring, P.; Meng, J.

    2010-06-15

    The empirical relativistic density-dependent, point-coupling energy density functional, adjusted exclusively to experimental binding energies of a large set of deformed nuclei with Aapprox =150-180 and Aapprox =230-250, is tested with spectroscopic data for {sup 166}Er and {sup 240}Pu. Starting from constrained self-consistent triaxial relativistic Hartree-Bogoliubov calculations of binding energy maps as functions of the quadrupole deformation in the beta-gamma plane, excitation spectra and E2 transition probabilities are calculated as solutions of the corresponding microscopic collective Hamiltonian in five dimensions for quadrupole vibrational and rotational degrees of freedom and compared with available data on low-energy collective states.

  20. Completion Report for Well ER-12-4, Corrective Action Unit 99: Rainier Mesa - Shoshone Mountain (includes Errata Sheet)

    SciTech Connect (OSTI)

    U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office; Bechtel Nevada

    2006-05-01

    Well ER-12-4 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office, in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. This well was drilled in May 2005, as part of a hydrogeologic investigation program for the Rainier Mesa-Shoshone Mountain Corrective Action Unit in the north-central portion of the Nevada Test Site. The well is located on Rainier/Aqueduct Mesa, northwest of Yucca Flat, within Area 12 of the Nevada Test Site. The well provided information regarding the radiological and physical environment near underground nuclear tests conducted in U12t Tunnel, information on the pre-Tertiary rocks in the area, and depth to the regional water table.

  1. Well Completion Report for Well ER-20-11, Corrective Action Units 101 and 102: Central and Western Pahute Mesa

    SciTech Connect (OSTI)

    NSTec Environmental Management

    2013-02-27

    Well ER-20-11 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of the Nevada Environmental Management Operations Underground Test Area (UGTA) Activity at the Nevada National Security Site (formerly Nevada Test Site), Nye County, Nevada. The well was drilled in September 2012 as part of the Central and Western Pahute Mesa Corrective Action Unit Phase II drilling program. Well ER-20-11 was constructed to further investigate the nature and extent of radionuclidecontaminated groundwater encountered in two nearby UGTA wells, to help define hydraulic and transport parameters for the contaminated Benham aquifer, and to provide data for the UGTA hydrostratigraphic framework model. The 44.5-centimeter (cm) surface hole was drilled to a depth of 520.0 meters (m) and cased with 34.0-cm casing to 511.5 m. The hole diameter was then decreased to 31.1 cm, and the borehole was drilled to a total depth of 915.6 m. The hole was completed to allow access for hydrologic testing and sampling in the target aquifer, which is a lava-flow aquifer known as the Benham aquifer. The completion casing string, set to the depth of 904.3 m, consists of a string of 6 5/8-inch (in.) stainless-steel casing hanging from a string of 7 5/8-in. carbon-steel casing. The stainless-steel casing has one slotted interval at 796.3 to 903.6 m. One piezometer string was installed, which consists of 2 7/8-in. stainless-steel tubing that hangs from 2 3/8-in. carbon-steel tubing via a crossover sub. This string was landed at 903.8 m and is slotted in the interval 795.3 to 903.1 m. Data collected during and shortly after hole construction include composite drill cuttings samples collected every 3.0 m, various geophysical logs, fluid samples (for groundwater chemistry analysis and tritium measurements), and water-level measurements. The well penetrated 915.6 m of Tertiary volcanic rock, including one saturated lava flow aquifer. Measurements on

  2. Completion Report for Well ER-EC-12 Corrective Action Units 101 and 102: Central and Western Pahute Mesa

    SciTech Connect (OSTI)

    NSTec Environmental Management

    2011-04-30

    Well ER-EC-12 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of the Nevada Environmental Restoration Project at the Nevada National Security Site (formerly known as the Nevada Test Site), Nye County, Nevada. The well was drilled in June and July 2010 as part of the Pahute Mesa Phase II drilling program. The primary purpose of the well was to provide detailed hydrogeologic information in the Tertiary volcanic section in the area between Pahute Mesa and the Timber Mountain caldera complex that will help address uncertainties within the Pahute Mesa–Oasis Valley hydrostratigraphic model. In particular, the well was intended to help define the structural position and hydraulic parameters for volcanic aquifers potentially down-gradient from historic underground nuclear tests on Pahute Mesa. It may also be used as a long-term monitoring well.

  3. Completion Report for Well ER-EC-15 Corrective Action Units 101 and 102: Central and Western Pahute Mesa

    SciTech Connect (OSTI)

    NSTec Environmental Management

    2011-05-31

    Well ER-EC-15 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of the Nevada Environmental Restoration Project at the Nevada National Security Site (formerly known as the Nevada Test Site), Nye County, Nevada. The well was drilled in October and November 2010, as part of the Pahute Mesa Phase II drilling program. The primary purpose of the well was to provide detailed hydrogeologic information in the Tertiary volcanic section in the area between Pahute Mesa and the Timber Mountain caldera complex that will help address uncertainties within the Pahute Mesa–Oasis Valley hydrostratigraphic model. In particular, the well was intended to help define the structural position and hydraulic parameters of volcanic aquifers potentially down-gradient from underground nuclear tests on Pahute Mesa. It may also be used as a long-term monitoring well.

  4. Completion Report for Well ER-EC-13 Corrective Action Units 101 and 102: Central and Western Pahute Mesa

    SciTech Connect (OSTI)

    NSTec Environmental Management

    2011-05-31

    Well ER-EC-13 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office, in support of the Nevada Environmental Restoration Project at the Nevada National Security Site (formerly Nevada Test Site), Nye County, Nevada. The well was drilled in October 2010 as part of the Pahute Mesa Phase II drilling program. A main objective was to provide detailed hydrogeologic information for the Fortymile Canyon composite unit hydrostratigraphic unit in the Timber Mountain moat area, within the Timber Mountain caldera complex, that will help address uncertainties within the Pahute Mesa–Oasis Valley hydrostratigraphic framework model. This well may also be used as a long-term monitoring well.

  5. Single and two-photon fluorescence control of Er{sup 3+} ions by phase-shaped femtosecond laser pulse

    SciTech Connect (OSTI)

    Zhang, Shian Ding, Jingxin; Lu, Chenhui; Jia, Tianqing; Sun, Zhenrong; Xu, Shuwu; Qiu, Jianrong

    2014-01-06

    We experimentally demonstrate the control of the single and two-photon fluorescence (SPF and TPF) in Er{sup 3+} ions by shaping the femtosecond laser pulse with a π or square phase modulation. With the low laser intensity (8.4 × 10{sup 10} W/cm{sup 2}), SPF keeps a constant while TPF is effectively suppressed by the two control schemes. With the high laser intensity (1.2 × 10{sup 13} W/cm{sup 2}), both SPF and TPF are simultaneously enhanced or suppressed by the π phase modulation, and SPF is enhanced while TPF is effectively suppressed by the square phase modulation. The up/down-conversion fluorescence enhancement, suppression, or tuning by the optical control method can greatly expand its applications in various related fields.

  6. Synthesis and characterization of R{sub 2}MnTiO{sub 7} (R = Y and Er) pyrochlores oxides

    SciTech Connect (OSTI)

    Martnez-Coronado, R.; Alonso, J.A.; Fernndez, M.T.

    2013-09-01

    Graphical abstract: - Abstract: New pyrochlore-like phases of composition R{sub 2}MnTiO{sub 7} (R = Er and Y) have been synthesized by a soft-chemistry procedure involving citrates of the different metal ions followed by thermal treatments at moderate temperatures (850 C for 12 h in air). A characterization by X-ray diffraction and neutron powder diffraction (NPD) has been carried out in order to determine the crystal structure features: these phyrochlores are cubic, space group Fd-3m, defining an intrinsically frustrated three-dimensional system. The Rietveld-refinement from NPD data at room temperature evidences an antisite cation disorder (distribution of Mn between A and B positions) that is accompanied by an increment of the oxygen-vacancy concentration due to the reduction of Mn{sup 4+} at the B position to Mn{sup 2+} at the A position. Thermogravimetric analysis (TGA) was useful to evaluate the stability of these oxides in reducing conditions up to 500 C. Magnetic susceptibility measurements indicate a ferromagnetic behavior, due to the random distribution of Mn{sup 4+} ions in the octahedral sublattice. At lower temperatures there is a polarization of the R{sup +3} magnetic moments, which also participate in the magnetic structure. Aiming to evaluate these materials as possible electrodes for solid oxide fuel cells (SOFC) we determined that the thermal expansion coefficients between 100 and 900 C perfectly match with those of the usual electrolytes; however, these pyrochlore oxides display a semiconductor-like behavior with poor conductivity values, e.g. 6 10{sup ?3} cm{sup ?1} at 850 C for Er, which would prevent its use as MIEC (mixed ionic-electronic conductors) oxides in SOFC devices.

  7. A new oxytelluride: Perovskite and CsCl intergrowth in Ba{sub 3}Yb{sub 2}O{sub 5}Te

    SciTech Connect (OSTI)

    Whalen, J.B.; Besara, T.; Vasquez, R.; Herrera, F.; Sun, J.; Ramirez, D.; Stillwell, R.L.; and others

    2013-07-15

    The new oxytelluride Ba{sub 3}Yb{sub 2}O{sub 5}Te was obtained from an alkaline earth flux. Ba{sub 3}Yb{sub 2}O{sub 5}Te crystallizes in the tetragonal space group P4/mmm (#123), with a=4.3615(3) Å and c=11.7596(11) Å, Z=1. The structure combines two distinct building blocks, a Ba{sub 2}Yb{sub 2}O{sub 5} perovskite-like double layer with square bipyramidal coordination of the ytterbium ions, and a CsCl-type BaTe layer. Short range magnetic order is apparent at below 5 K, with the magnetic behavior above this temperature dominated by crystal field effects. The structure may be considered as an analog to the Ruddlesden–Popper phases, where the NaCl-type layer has been replaced by the CsCl-type layer. The two-dimensional magnetic behavior is expected based on the highly anisotropic nature of the structure. - Graphical abstract: Optical images of Ba{sub 3}Yb{sub 2}O{sub 5}Te in transmission (left) and reflected (right) light, with atomic unit cell overlay. - Highlights: • Single crystal synthesis and characterization of a new phase, Ba{sub 3}Yb{sub 2}O{sub 5}Te. • The structure features the BaTe high pressure polymorph intergrowth. • Magnetic susceptibility measurements show short range 2 dimensional ordering. • Heat capacity measurements show a feature at the magnetic ordering temperature. • Optical reflectivity measurements show a {sup 2}F{sub 7/2}→{sup 2}F{sub 5/2} absorption at 976 nm.

  8. Highly constrained ferroelectric [BaTiO{sub 3}]{sub (1−x)Λ}/[BaZrO{sub 3}]{sub xΛ} superlattices: X-ray diffraction and Raman spectroscopy

    SciTech Connect (OSTI)

    Belhadi, J.; El Marssi, M. Gagou, Y.; El Mendili, Y.; Bouyanfif, H.; Yuzyuk, Yu. I.; Raevski, I. P.; Wolfman, J.

    2014-07-21

    We report an x-ray diffraction (XRD) and a Raman-scattering investigation of ferroelectric/paraelectric superlattices [BaTiO{sub 3}] {sub (1−x)Λ}/[BaZrO{sub 3}]{sub xΛ} for which the composition varied, 0.15 ≤ x ≤ 0.85, while the superlattice (SL) modulation period Λ was kept constant at about 100 Å. The samples were epitaxially grown by pulsed laser deposition on MgO substrates buffered with La{sub 0.5}Sr{sub 0.5}CoO{sub 3}. Based on the XRD analysis and on polarized Raman spectra, we have showed that the large strain in SLs induced ferroelectricity in BaZrO{sub 3} (BZ) for all SLs, a material that is paraelectric in the bulk form at any temperature and in the single film. The induced polar axis in BZ layers is perpendicular to the plane of substrate while BaTiO{sub 3} (BT) layers exhibit in-plane polar orientation. Raman spectroscopy revealed a lattice ordering in SLs due to the misfit strain generated by the large lattice mismatch between the alternating BZ and BT layers. This strain induced a huge upward frequency of the lowest E(1TO) soft mode from 60 cm{sup −1} in the BT single film to 215 cm{sup −1} in the SL with x = 0.85. These results show that in spite of relatively large periodicity of SLs, they are highly constrained and the variation of BZ ratio allowed modifying strains between layers. The temperature dependence of the Raman spectra for BT{sub 0.3Λ}/BZ{sub 0.7Λ} and BT{sub 0.7Λ}/BZ{sub 0.3Λ} samples revealed giant shift of the ferroelectric phase transition. The phase transition temperature was found to be upshifted by about 300 °C with respect to BT single crystal.

  9. Final Report for Grant DE-FG02-91ER40690 for the period 12/1/2010 to 4/30/2014

    SciTech Connect (OSTI)

    Durkin, Stan; Hill, Chris; Kass, Richard; Braaten, Eric; Mathur, Samir; Raby, Stuart; Shigemitsu, Junko; Gan, K. K.; Kagan, Harris; Hughes, Richard E.; Winer, Brian L.; Honscheid, Klaus

    2014-07-22

    This is the #12;final report for The Ohio State University high energy physics grant DE-FG02- 91ER40690. The activities of the various Tasks are briefy summarized over the previous grant period. The support from the Department of Energy is greatly appreciated.

  10. Characterisation of Ba(OH){sub 2}–Na{sub 2}SO{sub 4}–blast furnace slag cement-like composites for the immobilisation of sulfate bearing nuclear wastes

    SciTech Connect (OSTI)

    Mobasher, Neda; Bernal, Susan A.; Hussain, Oday H.; Apperley, David C.; Kinoshita, Hajime; Provis, John L.

    2014-12-15

    Soluble sulfate ions in nuclear waste can have detrimental effects on cementitious wasteforms and disposal facilities based on Portland cement. As an alternative, Ba(OH){sub 2}–Na{sub 2}SO{sub 4}–blast furnace slag composites are studied for immobilisation of sulfate-bearing nuclear wastes. Calcium aluminosilicate hydrate (C–A–S–H) with some barium substitution is the main binder phase, with barium also present in the low solubility salts BaSO{sub 4} and BaCO{sub 3}, along with Ba-substituted calcium sulfoaluminate hydrates, and a hydrotalcite-type layered double hydroxide. This reaction product assemblage indicates that Ba(OH){sub 2} and Na{sub 2}SO{sub 4} act as alkaline activators and control the reaction of the slag in addition to forming insoluble BaSO{sub 4}, and this restricts sulfate availability for further reaction as long as sufficient Ba(OH){sub 2} is added. An increased content of Ba(OH){sub 2} promotes a higher degree of reaction, and the formation of a highly cross-linked C–A–S–H gel. These Ba(OH){sub 2}–Na{sub 2}SO{sub 4}–blast furnace slag composite binders could be effective in the immobilisation of sulfate-bearing nuclear wastes.

  11. Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+}: A novel blue emitting phosphor for white LEDs

    SciTech Connect (OSTI)

    Li, Panlai Wang, Zhijun Yang, Zhiping; Guo, Qinglin

    2014-12-15

    Graphical abstract: Under the 350 nm radiation excitation, Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} has a broad blue emission band. When the temperature turned up to 150 C, the emission intensity of Ba{sub 1.97}B{sub 2}O{sub 5}:0.03Ce{sup 3+} is 63.4% of the initial value at room temperature. The activation energy ?E is calculated to be 0.25 eV, which prove the good thermal stability of Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+}. All the properties indicate that Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} may have potential application in white LEDs. - Highlights: Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} has a broad blue emission band under the 350 nm radiation excitation. Emission intensity of Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} is 63.4% (150 C) of the initial value (30 C). The activation energy ?E for thermal quenching is 0.25 eV. - Abstract: A novel blue emitting phosphor Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} is synthesized by a high temperature solid state method. The luminescent property and the thermal stability of Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} are investigated. Under the 350 nm radiation excitation, Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} has a broad blue emission band, and the peak locates at 417 nm which is assigned to the 5d{sup 1}4f{sup 1} transition of Ce{sup 3+}. It is further proved that the dipoledipole interaction results in the concentration quenching of Ce{sup 3+} in Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+}. When the temperature turned up to 150 C, the emission intensity of Ba{sub 1.97}B{sub 2}O{sub 5}:0.03Ce{sup 3+} is 63.4% of the initial value at room temperature. The activation energy ?E is calculated to be 0.25 eV, which prove the good thermal stability of Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+}. All the properties indicate that Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} may have potential application in white LEDs.

  12. (Sr,Ba)(Si,Ge){sub 2} for thin-film solar-cell applications: First-principles study

    SciTech Connect (OSTI)

    Kumar, Mukesh E-mail: mkgarg79@gmail.com; Umezawa, Naoto; Imai, Motoharu

    2014-05-28

    In order to meet the increasing demand for electric power generation from solar energy conversion, the development of efficient light absorber materials has been awaited. To this end, the electronic and optical properties of advanced alkaline-earth-metals disilicides and digermanides (SrSi{sub 2}, BaSi{sub 2}, SrGe{sub 2}, and BaGe{sub 2}) are studied by means of the density functional theory using HSE06 exchange-correlation energy functional. Our calculations show that all these orthorhombic structured compounds have fundamental indirect band gaps in the range E{sub g} ? 0.891.25 eV, which is suitable for solar cell applications. The estimated lattice parameters and band gaps are in good agreement with experiments. Our calculations show that the electronic band structures of all four compounds are very similar except in the vicinity of the ?-point. The valence band of these compounds is made up by Si(Ge)-p states, whereas the conduction band is composed of Sr(Ba)-d states. Their band alignments are carefully determined by estimating the work function of each compound using slab model. The optical properties are discussed in terms of the complex dielectric function ?(?)?=??{sub 1}(?)?+?i?{sub 2}(?). The static and high-frequency dielectric constants are calculated, taking into account the ionic contribution. The absorption coefficient ?(?) demonstrates that a low energy dispersion of the conduction band, which results in a flat conduction band minimum, leads to large optical activity in these compounds. Therefore, alkaline-earth-metals disilicides and digermanides possess great potential as light absorbers for applications in thin-film solar cell technologies.

  13. Electromotive force responses of Cl[sub 2] gas sensor using BaCl[sub 2]-KCl solid electrolyte

    SciTech Connect (OSTI)

    Aono, Hiromichi; Sugimoto, Eisuke . Dept. of Industrial Chemistry); Mori, Yoshiaki; Okajima, Yasuhiro . Niihama Research Lab.)

    1993-11-01

    Chlorine is the most important halogen in industrial production. Chlorine exhaust gas has become a serious problem with regard to air pollution and acid rain in recent years. Solid electrolyte-type gas sensors are superior for SO[sub x] or CO[sub 2] detection because of their rapid response. A Cl[sub 2] gas sensor using BaCl[sub 2]-KCl solid electrolyte was investigated. The conductivity was greatly enhanced by KCl doping of the (1 [minus] x)BaCl[sub 2][minus]x KCl system, and a maximum conductivity of 5.6 [times] 10[sup [minus]5]S [times] cm[sup [minus]1] at 573 K was obtained for x = 0.02. The sensor probe was prepared by a melting method at 1,373 K. The electromotive force (EMF) measurement with the Cl[sub 2] gas sensor using the 0.97BaCl[sub 2]-0.03KCl solid electrolyte was performed with an Ag-AgCl solid reference electrode and an RuO[sub 2] measuring electrode. Good agreement between the measured and the calculated EMF values was obtained for Cl[sub 2] gas concentrations from 50 to 10,000 ppm at 623 K. The EMF response time with a change in Cl[sub 2] concentration is ca. 1 min for above 100 ppm and 2 to 5 min for lower concentrations. The measured EMF was not influenced by O[sub 2] or CO[sub 2] gas concentration. This sensor probe was very stable in the presence of water vapor at 623 K during a 90 day test period.

  14. Temperature driven nano-domain evolution in lead-free Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}-50(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} piezoceramics

    SciTech Connect (OSTI)

    Lu, Shengbo Xu, Zhengkui; Su, Shi; Zuo, Ruzhong

    2014-07-21

    Hierarchical micro- and nanoscale domain structures in Pb-free Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}-50(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} piezoceramics were investigated by transmission electron microscopy. In situ heating and cooling studies of domain structure evolution reveal an irreversible domain transformation from a wedge-shaped rhombohedral nanodomain structure to a lamellar tetragonal domain structure, which could be associated with strong piezoelectricity in Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}-50(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} piezoceramics.

  15. 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.; Wang, X. D.; Zhao, C. Z.; Liu, M. F.; Liu, J. M.

    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.

  16. Curcumin attenuates glutamate neurotoxicity in the hippocampus by suppression of ER stress-associated TXNIP/NLRP3 inflammasome activation in a manner dependent on AMPK

    SciTech Connect (OSTI)

    Li, Ying; Li, Jia; Li, Shanshan; Li, Yi; Wang, Xiangxiang; Liu, Baolin; Fu, Qiang; Ma, Shiping

    2015-07-01

    Curcumin is a natural polyphenolic compound in Curcuma longa with beneficial effects on neuronal protection. This study aims to investigate the action of curcumin in the hippocampus subjected to glutamate neurotoxicity. Glutamate stimulation induced reactive oxygen species (ROS), endoplasmic reticulum stress (ER stress) and TXNIP/NLRP3 inflammasome activation, leading to damage in the hippocampus. Curcumin treatment in the hippocampus or SH-SY5Y cells inhibited IRE1α and PERK phosphorylation with suppression of intracellular ROS production. Curcumin increased AMPK activity and knockdown of AMPKα with specific siRNA abrogated its inhibitory effects on IRE1α and PERK phosphorylation, indicating that AMPK activity was essential for the suppression of ER stress. As a result, curcumin reduced TXNIP expression and inhibited NLRP3 inflammasome activation by downregulation of NLRP3 and cleaved caspase-1 induction, and thus reduced IL-1β secretion. Specific fluorescent probe and flow cytometry analysis showed that curcumin prevented mitochondrial malfunction and protected cell survival from glutamate neurotoxicity. Moreover, oral administration of curcumin reduced brain infarct volume and attenuated neuronal damage in rats subjected to middle cerebral artery occlusion. Immunohistochemistry showed that curcumin inhibited p-IRE1α, p-PERK and NLRP3 expression in hippocampus CA1 region. Together, these results showed that curcumin attenuated glutamate neurotoxicity by inhibiting ER stress-associated TXNIP/NLRP3 inflammasome activation via the regulation of AMPK, and thereby protected the hippocampus from ischemic insult. - Highlights: • Curcumin attenuates glutamate neurotoxicity in the hippocampus. • Curcumin suppresses ER stress in glutamate-induced hippocampus slices. • Curcumin inhibits TXNIP/NLRP3 inflammasome activation. • Regulation of AMPK by curcumin contributes to suppressing ER stress.

  17. Up-regulation of K{sub ir}2.1 by ER stress facilitates cell death of brain capillary endothelial cells

    SciTech Connect (OSTI)

    Kito, Hiroaki; Yamazaki, Daiju; Department of Biological Chemistry, Kyoto University, Graduate School of Pharmaceutical Sciences, Kyoto; Department of Molecular Neurobiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya ; Ohya, Susumu; Yamamura, Hisao; Asai, Kiyofumi; Imaizumi, Yuji

    2011-07-29

    Highlights: {yields} We found that application of endoplasmic reticulum (ER) stress with tunicamycin to brain capillary endothelial cells (BCECs) induced cell death. {yields} The ER stress facilitated the expression of inward rectifier K{sup +} channel (K{sub ir}2.1) and induced sustained membrane hyperpolarization. {yields} The membrane hyperpolarization induced sustained Ca{sup 2+} entry through voltage-independent nonspecific cation channels and consequently facilitated cell death. {yields} The K{sub ir}2.1 up-regulation by ER stress is, at least in part, responsible for cell death of BCECs under pathological conditions. -- Abstract: Brain capillary endothelial cells (BCECs) form blood brain barrier (BBB) to maintain brain homeostasis. Cell turnover of BCECs by the balance of cell proliferation and cell death is critical for maintaining the integrity of BBB. Here we found that stimuli with tunicamycin, endoplasmic reticulum (ER) stress inducer, up-regulated inward rectifier K{sup +} channel (K{sub ir}2.1) and facilitated cell death in t-BBEC117, a cell line derived from bovine BCECs. The activation of K{sub ir} channels contributed to the establishment of deeply negative resting membrane potential in t-BBEC117. The deep resting membrane potential increased the resting intracellular Ca{sup 2+} concentration due to Ca{sup 2+} influx through non-selective cation channels and thereby partly but significantly regulated cell death in t-BBEC117. The present results suggest that the up-regulation of K{sub ir}2.1 is, at least in part, responsible for cell death/cell turnover of BCECs induced by a variety of cellular stresses, particularly ER stress, under pathological conditions.

  18. Exposure of Jurkat cells to bis (tri-n-butyltin) oxide (TBTO) induces transcriptomics changes indicative for ER- and oxidative stress, T cell activation and apoptosis

    SciTech Connect (OSTI)

    Katika, Madhumohan R.; Hendriksen, Peter J.M.; Loveren, Henk van; Peijnenburg, Ad

    2011-08-01

    Tributyltin oxide (TBTO) is an organotin compound that is widely used as a biocide in agriculture and as an antifouling agent in paints. TBTO is toxic for many cell types, particularly immune cells. The present study aimed to identify the effects of TBTO on the human T lymphocyte cell line Jurkat. Cells were treated with 0.2 and 0.5 {mu}M TBTO for 3, 6, 12 and 24 h and then subjected to whole genome gene expression microarray analysis. The biological interpretation of the gene expression profiles revealed that endoplasmic reticulum (ER) stress is among the earliest effects of TBTO. Simultaneously or shortly thereafter, oxidative stress, activation of NFKB and NFAT, T cell activation, and apoptosis are induced. The effects of TBTO on genes involved in ER stress, NFAT pathway, T cell activation and apoptosis were confirmed by qRT-PCR. Activation and nuclear translocation of NFATC1 and the oxidative stress response proteins NRF2 and KEAP1 were confirmed by immunocytology. Taking advantage of previously published microarray data, we demonstrated that the induction of ER stress, oxidative stress, T cell activation and apoptosis by TBTO is not unique for Jurkat cells but does also occur in mouse thymocytes both ex vivo and in vivo and rat thymocytes ex vivo. We propose that the induction of ER stress leading to a T cell activation response is a major factor in the higher sensitivity of immune cells above other types of cells for TBTO. - Research Highlights: > The human T lymphocyte cell line Jurkat was exposed to TBTO. > Whole-genome microarray experiments were performed. > Data analysis revealed the induction of ER stress and activation of NFAT and NFKB. > Exposure to TBTO also led to T cell activation, oxidative stress and apoptosis.

  19. Interfacial chemical reaction and multiple gap state formation on three layer cathode in organic light-emitting diode: Ca/BaF{sub 2}/Alq{sub 3}

    SciTech Connect (OSTI)

    Kim, Tae Gun; Kim, Jeong Won; Lee, Hyunbok; Yi, Yeonjin; Lee, Seung Mi

    2015-07-14

    A three layer cathode is a promising stack structure for long lifetime and high efficiency in organic light-emitting diodes. The interfacial chemical reactions and their effects on electronic structures for alkaline-earth metal (Ca, Ba)/Alq{sub 3} [tris(8-hydroxyquinolinato)aluminum] and Ca/BaF{sub 2}/Alq{sub 3} are investigated using in-situ X-ray and ultraviolet photoelectron spectroscopy, as well as molecular model calculation. The BaF{sub 2} interlayer initially prevents direct contact between Alq{sub 3} and the reactive Ca metal, but it is dissociated into Ba and CaF{sub 2} by the addition of Ca. As the Ca thickness increases, the Ca penetrates the interlayer to directly participate in the reaction with the underlying Alq{sub 3}. This series of chemical reactions takes place irrespective of the BaF{sub 2} buffer layer thickness as long as the Ca overlayer thickness is sufficient. The interface reaction between the alkaline-earth metal and Alq{sub 3} generates two energetically separated gap states in a sequential manner. This phenomenon is explained by step-by-step charge transfer from the alkaline-earth metal to the lowest unoccupied molecular orbital states of Alq{sub 3}, forming new occupied states below the Fermi level.

  20. Dissociation of misfit and threading dislocations in Ba{sub 0.75}Sr{sub 0.25}TiO{sub 3} epitaxial film

    SciTech Connect (OSTI)

    Wang, Y.Q.; Liang, W.S.; Petrov, Peter Kr.; Alford, Neil McN.

    2011-03-15

    Ba{sub 0.75}Sr{sub 0.25}TiO{sub 3} film was epitaxially grown on a (001) LaAlO{sub 3} substrate using single-target pulsed laser deposition. The dissociation of misfit and threading dislocations in the epitaxial Ba{sub 0.75}Sr{sub 0.25}TiO{sub 3} film was investigated using high-resolution transmission electron microscopy (HRTEM). For a misfit dislocation with a Burgers vector of [200], it was shown that it could dissociate into four partial dislocations with Burgers vector of type 1/2 < 110>. For the threading dislocations, it was found that they usually coexist with stacking faults. The formation mechanism for the dissociated dislocations was discussed. All the dislocations can relieve the local strain in the Ba{sub 0.75}Sr{sub 0.25}TiO{sub 3} epitaxial film. - Research Highlights: {yields}Dissociation behaviour of misfit dislocations in Ba{sub 0.75}Sr{sub 0.25}TiO{sub 3} film. {yields}Dissociation behaviour of threading dislocations in Ba{sub 0.75}Sr{sub 0.25}TiO{sub 3} film. {yields}Formation mechanism of the dissociated dislocations.

  1. High temperature phase stabilities and electrochemical properties of InBaCo4-xZnxO7 cathodes for intermediate temperature solid oxide fuel cells

    SciTech Connect (OSTI)

    Kim, Jung-Hyun; Young Nam, Kim; Bi, Zhonghe; Manthiram, Arumugam; Paranthaman, Mariappan Parans; Huq, Ashfia

    2011-01-01

    InBaCo4-xZnxO7 oxides have been synthesized and characterized as cathode materials for intermediate temperature solid oxide fuel cells (IT-SOFC). The effect of Zn substitution for Co on the structure, phase stability, thermal expansion, and electrochemical properties of the InBaCo4-xZnxO7 has been investigated. The increase in the Zn content from x = 1 to 1.5 improves the high temperature phase stability at 600 oC and 700 oC for 100 h, and chemical stability against a Gd0.2Ce0.8O1.9 (GDC) electrolyte. Thermal expansion coefficient (TEC) values of the InBaCo4-xZnxO7 (x = 1, 1.5, 2) specimens were determined to be 8.6 10-6 9.6 10-6 /oC in the range of 80 900 oC, which provides good thermal expansion compatibility with the standard SOFC electrolyte materials. The InBaCo4-xZnxO7 + GDC (50:50 wt. %) composite cathodes exhibit improved cathode performances compared to those obtained from the simple InBaCo4-xZnxO7 cathodes due to the extended triple-phase boundary (TPB) and enhanced oxide-ion conductivity through the GDC portion in the composites.

  2. Zn-Doping Dependence of Stripe Order in La1.905Ba0.095CuO4

    SciTech Connect (OSTI)

    Hucker, M.; Zimmermann, M.v.; Xu, Z.J.; Wen, J.S.; Gu, G.D.; Tian, W.; Zarestky, J.; Tranquada, J.M.

    2011-04-01

    The effect of Zn-doping on the stripe order in La{sub 1.905}Ba{sub 0.095}CuO{sub 4} has been studied by means of x-ray and neutron diffraction as well as magnetization measurements. While 1% Zn leads to an increase of the spin stripe order, it unexpectedly causes a wipe out of the visibility of the charge stripe order. A magnetic field of 10 Tesla applied along the c-axis has no reversing effect on the charge order. We compare this observation with the Zn-doping dependence of the crystal structure, superconductivity, and normal state magnetism.

  3. Photo-induced change of dielectric response in BaCoSiO{sub 4} stuffed tridymite

    SciTech Connect (OSTI)

    Taniguchi, Hiroki Okamura, Takuma; Yamamoto, Takafumi; Okazaki, Ryuji; Terasaki, Ichiro; Moriwake, Hiroki; Kuwabara, Akihide; Itoh, Mitsuru

    2014-04-28

    The photodielectric effect is demonstrated in Mott-insulator BaCoSiO{sub 4} with a stuffed-tridymite-type structure under irradiation of visible light at 365?nm. The real part of dielectric permittivity is enhanced by ?300% with little increase of tan?? in a low-frequency region. Results of diffuse reflectance spectroscopy, first-principles calculations and dielectric measurements suggest that the photodielectric effect stems from a response of photo-excited electrons in an unoccupied upper-Hubbard band for 3d-orbitals of cobalt, which have significantly small mobility due to the unique configuration of Co ions in the stuffed-tridymite-type structure.

  4. NMR evidence for inhomogeneous nematic fluctuations in BaFe2(As1-xPx)2

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Dioguardi, A. P.; Kissikov, T.; Lin, C. H.; Shirer, K. R.; Lawson, M. M.; Grafe, H. -J.; Chu, J. -H.; Fisher, I. R.; Fernandes, R. M.; Curro, N. J.

    2016-03-10

    We present evidence for nuclear spin-lattice relaxation driven by glassy nematic fluctuations in isovalent P-doped BaFe2As2 single crystals. Both the 75As and 31P sites exhibit a stretched-exponential relaxation similar to the electron-doped systems. By comparing the hyperfine fields and the relaxation rates at these sites we find that the As relaxation cannot be explained solely in terms of magnetic spin fluctuations. We demonstrate that nematic fluctuations couple to the As nuclear quadrupolar moment and can explain the excess relaxation. Lastly, these results suggest that glassy nematic dynamics are a common phenomenon in the iron-based superconductors.

  5. Growth of epitaxial (Sr,Ba){sub n+1}Ru{sub n}O{sub 3n+1} films

    SciTech Connect (OSTI)

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

    1997-12-01

    We have grown epitaxial (Sr,Ba) (n+1)Ru(n)O(3n+1) films, n = 1, 2, and infinity, by pulsed laser deposition (PLD) and controlled their orientation by choosing appropriate substrates. The growth conditions yielding phase pure films have been mapped out. Resistivity versus temperature measurements show that both a and c axis films of Sr2RuO4 are metallic, but not superconducting. The latter is probably due to the presence of low-level impurities that are difficult to avoid given the target preparation process involved in growing these films by PLD.

  6. Mixture formation of Er{sub x}Yb{sub 2-x}Si{sub 2}O{sub 7} and Er{sub x}Yb{sub 2-x}O{sub 3} on Si for broadening the C-band in an optical amplifier

    SciTech Connect (OSTI)

    Omi, Hiroo; Tawara, Takehiko; Abe, Yoshiyuki; Anagnosti, Maria

    2013-04-15

    Thin films composed of polycrystalline Er{sub x}Yb{sub 2-x}O{sub 3} grains and crystalline Er{sub x}Yb{sub 2-x}Si{sub 2}O{sub 7} layers were formed on a Si(111) substrate by RF - sputtering and subsequent thermal annealing in Ar gas ambient up to 1100 Degree-Sign C. The films were characterized by synchrotron radiation grazing incidence X-ray diffraction, cross-sectional transmission microscopy, energy dispersive X-ray spectrometry and micro photoluminescence measurements. In the annealed film of 950 Degree-Sign C it is observed that the I{sub 15/2} - I{sub 13/2} Er{sup 3+} photoluminescent transition exhibits simultaneously maximum intensity and peak width at room temperature. This effect satisfies the requirements for broadening the C-band of an optical amplifier on Si.

  7. Synthesis and electromagnetic properties of BaFe{sub 11.92}(LaNd){sub 0.04}O{sub 19}/titanium dioxide composites

    SciTech Connect (OSTI)

    Xie, Yu; Hong, Xiaowei; Liu, Jinmei; Le, Zhanggao; Huang, Feihui; Qin, Yuancheng; Zhong, Rong; Gao, Yunhua; Pan, Jianfei; Ling, Yun

    2014-02-01

    Graphical abstract: Due to combining different functions and characteristics of individual materials, hybrid nanocomposite materials can strengthen their applications. Magnetic-conductive nanocomposites are the promising materials with electromagnetic loss, which have synergetic behavior between magnetic and conductive materials. It is the first time to report the synthesis of BaFe{sub 11.92}(LaNd){sub 0.04}O{sub 19}/titanium dioxide (BF/TD) composites by the gel-precursor self-propagating combustion process. The influence of mass ratio of BF and TD on the electromagnetic properties of BaFe{sub 11.92}(LaNd){sub 0.04}O{sub 19}/titanium dioxide composites was studied. The tgδ{sub μ} and tgδ{sub ε} of BF–TD composites. - Highlights: • It is the first time to report BaFe{sub 11.92}(LaNd){sub 0.04}O{sub 19}/titanium dioxide composites. • The composites are prepared by the gel-precursor self-propagating combustion. • The electromagnetic properties could be adjusted by the mass ratio of BF and TD. • The introduction of TD enhances the dielectric loss and widens the frequency bands. • BF/TD composites will be microwave absorption materials with wide frequency band. - Abstract: Doped BaFe{sub 11.92}(LaNd){sub 0.04}O{sub 19}/titanium dioxide composites have been prepared by the gel-precursor self-propagating combustion process. The characterization of the composites are performed by Fourier transform infrared (FT-IR), X-ray diffraction (XRD), Differential thermal analysis-thermo gravimetry (DTA–TG), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM) and network analyzer. Both XRD and FT-IR indicate that the doped BaFe{sub 11.92}(LaNd){sub 0.04}O{sub 19}/titanium dioxide composites are successfully synthesized and there are some interactions between BaFe{sub 11.92}(LaNd){sub 0.04}O{sub 19} and titanium dioxide. DTA–TG analysis of BaFe{sub 11.92}(LaNd){sub 0.04}O{sub 19}/titanium dioxide composites shows that the composite gel

  8. Dielectric studies of BaTi{sub 0.96}Co{sub 0.04}O{sub 3} prepared via solid state route

    SciTech Connect (OSTI)

    Mishra, Ashutosh Mishra, Niyati Jarabana, Kanaka Mahalakshmi Bisen, Supriya

    2014-04-24

    The synthesis and characterization of cobalt doped barium titanate; BaTi{sub 0.96}Co{sub 0.04}O{sub 3} was investigated with a view to understand its structural and dielectric properties. A finest possible sample of Cobalt doped micro particles of BaTiO{sub 3} (BTO) with possible cubic structure via a solid-state route was prepared. Prepared samples were structural characterized by X-ray diffraction (XRD). The dielectric constant measurements of the sample above and below the Curie temperature were carried out at various frequencies. The Transition temperature is found shifted towards lower side from that of pure BaTiO{sub 3}.

  9. Structural evolution across the insulator-metal transition in oxygen-deficient BaTiO3-δ studied using neutron total scattering and Rietveld analysis

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jeong, I.-K.; Lee, Seunghun; Jeong, Se-Young; Won, C. J.; Hur, N.; Llobet, A.

    2011-08-29

    Oxygen-deficient BaTiO3-δ exhibits an insulator-metal transition with increasing δ. We performed neutron total scattering measurements to study structural evolution across an insulator-metal transition in BaTiO3-δ. Despite its significant impact on resistivity, slight oxygen reduction (δ=0.09) caused only a small disturbance on the local doublet splitting of Ti-O bond. This finding implies that local polarization is well preserved under marginal electric conduction. In the highly oxygen-deficient metallic state (δ=0.25), however, doublet splitting of the Ti-O bond became smeared. The smearing of the local Ti-O doublet is complemented with long-range structural analysis and demonstrates that the metallic conduction in the highly oxygen-reducedmore » BaTiO3-δ is due to the appearance of nonferroelectric cubic lattice.« less

  10. Completion Report for Well ER-20-7: Corrective Action Units 101 and 102: Central and Western Pahute Mesa

    SciTech Connect (OSTI)

    NSTec Environmental Restoration

    2010-04-28

    Well ER-20-7 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. The well was drilled in June 2009 as part of the Pahute Mesa Phase II drilling program. The primary purpose of the well was to further investigate migration of radionuclides from the nearby, up-gradient TYBO and BENHAM underground nuclear tests, which originally was discovered at Well Cluster ER-20-5. This well also provided detailed hydrogeologic information in the Tertiary volcanic section that will reduce uncertainties within the Pahute Mesa-Oasis Valley hydrostratigraphic framework model. The main 44.45-centimeter hole was drilled to a depth of 681.8 meters and cased with 33.97-centimeter casing to 671.7 meters. The hole diameter was then decreased to 31.12 centimeters, and the well was drilled to total depth of 894.9 meters. The completion string, set to the depth of 890.0 meters, consists of 14.13-centimeter stainless-steel casing hanging from 19.37-centimeter carbon-steel casing. The 14.13-centimeter stainless-steel casing has one continuous slotted interval open to the Topopah Spring aquifer. Data collected during and shortly after hole construction include composite drill cuttings samples collected every 3.0 meters, sidewall core samples from 20 depth intervals, various geophysical logs, water quality (primarily tritium) measurements, and water level measurements. The well penetrated 894.9 meters of Tertiary volcanic rock, including two saturated welded-tuff aquifers. A fluid level measurement was obtained during open-hole geophysical well logging for the upper, Tiva Canyon, aquifer at the depth of 615.7 meters on June 19, 2009. The fluid level measured in the open hole on June 27, 2009,after the total depth was reached and the upper aquifer was cased off, was also at the depth of 615.7 meters. Preliminary field measurements indicated 1

  11. Inclusion property of Cs, Sr, and Ba impurities in LiCl crystal formed by layer-melt crystallization

    SciTech Connect (OSTI)

    Choi, Jung-Hoon; Cho, Yung-Zun; Lee, Tae-Kyo; Eun, Hee-Chul; Kim, Jun-Hong; Park, Hwan-Seo; Kim, In-Tae; Park, Geun-Il

    2013-07-01

    Pyroprocessing is one of the promising technologies enabling the recycling of spent nuclear fuels from a commercial light water reactor (LWR). In general, pyroprocessing uses dry molten salts as electrolytes. In particular, LiCl waste salt after pyroprocessing contains highly radioactive I/II group fission products mainly composed of Cs, Sr, and Ba impurities. Therefore, it is beneficial to reuse LiCl salt in the pyroprocessing as an electrolyte for economic and environmental issues. Herein, to understand the inclusion property of impurities within LiCl crystal, the physical properties such as lattice parameter change, bulk modulus, and substitution enthalpy of a LiCl crystal having 0-6 at% Cs{sup +} or Ba{sup 2+} impurities under existence of 1 at% Sr{sup 2+} impurity were calculated via the first-principles density functional theory. The substitution enthalpy of LiCl crystals having 1 at% Sr{sup 2+} showed slightly decreased value than those without Sr{sup 2+} impurity. Therefore, through the substitution enthalpy calculation, it is expected that impurities will be incorporated within LiCl crystal as co-existed form rather than as a single component form. (authors)

  12. Acoustoelastic effect of textured (Ba,Sr)TiO{sub 3} thin films under an initial mechanical stress

    SciTech Connect (OSTI)

    Kamel, Marwa; Mseddi, Souhir; Njeh, Anouar; Ben Ghozlen, Mohamed Hédi; Donner, Wolfgang

    2015-12-14

    Acoustoelastic (AE) analysis of initial stresses plays an important role as a nondestructive tool in current engineering. Two textured BST (Ba{sub 0.65}Sr{sub 0.35}TiO{sub 3}) thin films, with different substrate to target distance, were grown on Pt(111)/TiO{sub 2}/SiO{sub 2}/Si(001) substrate by rf-magnetron sputtering deposition techniques. A conventional “sin{sup 2} ψ” method to determine residual stress and strain in BST films by X-ray diffraction is applied. A laser acoustic waves (LA-waves) technique is used to generate surface acoustic waves (SAW) propagating in both samples. Young's modulus E and Poisson ratio ν of BST films in different propagation directions are derived from the measured dispersion curves. Estimation of effective second-order elastic constants of BST thin films in stressed states is served in SAW study. This paper presents an original investigation of AE effect in prestressed Ba{sub 0.65}Sr{sub 0.35}TiO{sub 3} films, where the effective elastic constants and the effect of texture on second and third order elastic tensor are considered and used. The propagation behavior of Rayleigh and Love waves in BST thin films under residual stress is explored and discussed. The guiding velocities affected by residual stresses, reveal some shifts which do not exceed four percent mainly in the low frequency range.

  13. Determination of the phase diagram of the electron doped superconductor Ba(Fe1-xCox)2As2

    SciTech Connect (OSTI)

    Chu, Jiun-Haw; Analytis, James G.; Kucharczyk, Chris; Fisher, Ian R.; /Stanford U., Geballe Lab.

    2010-02-15

    Systematic measurements of the resistivity, heat capacity, susceptibility and Hall coefficient are presented for single crystal samples of the electron-doped superconductor Ba(Fe{sub 1-x}Co{sub x}){sub 2}As{sub 2}. These data delineate an x-T phase diagram in which the single magnetic/structural phase transition that is observed for undoped BaFe{sub 2}As{sub 2} at 134 K apparently splits into two distinct phase transitions, both of which are rapidly suppressed with increasing Co concentration. Superconductivity emerges for Co concentrations above x {approx}0.025, and appears to coexist with the broken symmetry state for an appreciable range of doping, up to x {approx} 0.06. The optimal superconducting transition temperature appears to coincide with the Co concentration at which the magnetic/structural phase transitions are totally suppressed, at least within the resolution provided by the finite step size between crystals prepared with different doping levels. Superconductivity is observed for a further range of Co concentrations, before being completely suppressed for x {approx} 0.018 and above. The form of this x-T phase diagram is suggestive of an association between superconductivity and a quantum critical point arising from suppression of the magnetic and/or structural phase transitions.

  14. Investigations of Ba{sub 3}BP{sub 3}O{sub 12}:Eu{sup 2+} single crystal as a scintillator

    SciTech Connect (OSTI)

    Zhang, Zhi-Jun; Hu, Guan-Qin; Wang, Hong; Zhu, Lin-Lin; Zhao, Jing-Tai

    2014-04-01

    Highlights: • Eu{sup 2+}-activated Ba{sub 3}BP{sub 3}O{sub 12} single crystals have been grown by the top-seeded solution growth method (TSSG) for the first time. • Ba{sub 3}BP{sub 3}O{sub 12}:Eu{sup 2+} single crystal exhibits wide transparency in the wavelength range from 250 to 700 nm. • Ba{sub 3}BP{sub 3}O{sub 12}:Eu{sup 2+} single crystal shows high overall scintillation efficiency (1.8 times of BGO) and moderate decay time (860 ns). - Abstract: Single crystals of Ba{sub 3}BP{sub 3}O{sub 12}:Eu{sup 2+} with high optical quality have been grown by the top-seeded solution growth (TSSG) method using BPO{sub 4}–NaF mixture as the flux. Ba{sub 3}BP{sub 3}O{sub 12}:Eu{sup 2+} single crystal exhibits wide transparency in the wavelength range from 250 to 700 nm, and shows a broad emission band in the wavelength range of 350–650 nm when excited by X-ray radiation. The overall scintillation efficiency is about 1.8 times of that of BGO crystal under the same conditions. Its room temperature fluorescence decay curve exhibits a single-exponent shape with decay time of about 860 ns. It is worth noting that Ba{sub 3}BP{sub 3}O{sub 12}:Eu{sup 2+} single crystal may be of great interest for applications in the field of scintillation materials considering its scintillation properties, as well as the good chemical stability.

  15. Preferential Eu Site Occupation and Its Consequences in the Ternary Luminescent HalidesAB2I5:Eu2+(A=Li–Cs;B=Sr, Ba)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Fang, C.  M.; Biswas, Koushik

    2015-07-22

    Several rare-earth-doped, heavy-metal halides have recently been identified as potential next-generation luminescent materials with high efficiency at low cost. AB2I5:Eu2+ (A=Li–Cs; B=Sr, Ba) is one such family of halides. Its members, such as CsBa2I5:Eu2+ and KSr2I5:Eu2+, are currently being investigated as high-performance scintillators with improved sensitivity, light yield, and energy resolution less than 3% at 662 keV. Within the AB2I5 family, our first-principles-based calculations reveal two remarkably different trends in Eu site occupation. The substitutional Eu ions occupy both eightfold-coordinated B1(VIII) and the sevenfold-coordinated B2(VII) sites in the Sr-containing compounds. However, in the Ba-containing crystals, Eu ions strongly prefer themore »B2(VII)sites. This random versus preferential distribution of Eu affects their electronic properties. The calculations also suggest that in the Ba-containing compounds one can expect the formation of Eu-rich domains. These results provide atomistic insight into recent experimental observations about the concentration and temperature effects in Eu-doped CsBa2I5. We discuss the implications of our results with respect to luminescent properties and applications. We also hypothesize Sr, Ba-mixed quaternary iodides ABaVIIISrVIII5:Eu as scintillators having enhanced homogeneity and electronic properties.« less

  16. High-pressure synthesis, crystal structure and magnetic properties of double perovskite oxide Ba{sub 2}CuOsO{sub 6}

    SciTech Connect (OSTI)

    Feng, Hai L.; Arai, Masao; Matsushita, Yoshitaka; Tsujimoto, Yoshihiro; Yuan, Yahua; Sathish, Clastin I.; He, Jianfeng; Tanaka, Masahiko; Yamaura, Kazunari

    2014-09-15

    A new compositional double perovskite oxide Ba{sub 2}CuOsO{sub 6} was synthesized under high-pressure (6 GPa) and high-temperature (1500 °C) conditions. The polycrystalline Ba{sub 2}CuOsO{sub 6} was characterized by synchrotron X-ray diffraction, thermogravimetric analysis, and magnetic susceptibility, isothermal magnetization, and specific heat measurements. The oxide crystallizes in a double-perovskite structure with an I4/m space group, in which Os(VI) and Cu(II) are ordered in the perovskite B-site. Ba{sub 2}CuOsO{sub 6} is electrically insulating with an activation energy of 0.813(2) eV and shows antiferromagnetic-like characteristics at temperatures of ∼55 K and ∼70 K. The results of the first-principle calculation suggested that the spin–orbit interaction of Os(VI) plays a substantial role in the insulating state. The Jahn–Teller distortion of CuO{sub 6} octahedra influences the magnetic characteristics with regard to possible two-dimensional magnetic correlations. - Graphical abstract: A new compositional double perovskite oxide Ba{sub 2}CuOsO{sub 6} synthesized by a high-pressure (6 GPa) and high-temperature (1500 °C) method. - Highlights: • A new compositional double perovskite oxide Ba{sub 2}CuOsO{sub 6} was synthesized. • Ba{sub 2}CuOsO{sub 6} is electrically insulating and antiferromagnetic below ∼70 K. • The Jahn–Teller distortion of CuO{sub 6} has relevance to possible magnetic anisotropy.

  17. (Y0.5In0.5)Ba(Co,Zn)4O7 cathodes with superior high-temperature phase stability for solid oxide fuel cells

    SciTech Connect (OSTI)

    Young Nam, Kim; Kim, Jung-Hyun; Paranthaman, Mariappan Parans; Manthiram, Arumugam; Huq, Ashfia

    2012-01-01

    (Y0.5In0.5)BaCo4-xZnxO7 (1.0 x 2.0) oxides crystallizing in a trigonal P31c structure have been synthesized and explored as cathode materials for solid oxide fuel cells (SOFC). At a given Zn content, the (Y0.5In0.5)BaCo4-xZnxO7 sample with 50 % Y and 50 % In exhibits much improved phase stability at intermediate temperatures (600 - 800 oC) compared to the samples with 100 % Y or In. However, the substitution of Zn for Co in (Y0.5In0.5)Ba(Co4-xZnx)O7 (1.0 x 2.0) decreases the amount of oxygen loss on heating, total electrical conductivity, and cathode performance in SOFC while providing good long-term phase stability at high temperatures. Among the various chemical compositions investigated in the (Y0.5In0.5)Ba(Co4-xZnx)O7 system, the (Y0.5In0.5)BaCo3ZnO7 sample offers a combination of good electrochemical performance and low thermal expansion coefficient (TEC) while maintaining superior phase stability at 600 800 oC for 100 h. Fuel cell performances of the (Y0.5In0.5)Ba(Co3Zn)O7 + Ce0.8Gd0.2O1.9 (GDC) (50 : 50 wt. %) composite cathodes collected with anode-supported single cell reveal a maximum power density value of 521 mW cm-2 at 700 oC.

  18. Preferential Eu Site Occupation and Its Consequences in the Ternary Luminescent HalidesAB2I5:Eu2+(A=Li–Cs;B=Sr, Ba)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Fang, C.  M.; Biswas, Koushik

    2015-07-22

    Several rare-earth-doped, heavy-metal halides have recently been identified as potential next-generation luminescent materials with high efficiency at low cost. AB2I5:Eu2+ (A=Li–Cs; B=Sr, Ba) is one such family of halides. Its members, such as CsBa2I5:Eu2+ and KSr2I5:Eu2+, are currently being investigated as high-performance scintillators with improved sensitivity, light yield, and energy resolution less than 3% at 662 keV. Within the AB2I5 family, our first-principles-based calculations reveal two remarkably different trends in Eu site occupation. The substitutional Eu ions occupy both eightfold-coordinated B1(VIII) and the sevenfold-coordinated B2(VII) sites in the Sr-containing compounds. However, in the Ba-containing crystals, Eu ions strongly prefer themore » B2(VII)sites. This random versus preferential distribution of Eu affects their electronic properties. The calculations also suggest that in the Ba-containing compounds one can expect the formation of Eu-rich domains. These results provide atomistic insight into recent experimental observations about the concentration and temperature effects in Eu-doped CsBa2I5. We discuss the implications of our results with respect to luminescent properties and applications. We also hypothesize Sr, Ba-mixed quaternary iodides ABaVIIISrVIII5:Eu as scintillators having enhanced homogeneity and electronic properties.« less

  19. Site-related near-infrared luminescence in MAl{sub 12}O{sub 19} (M = Ca, Sr, Ba):Fe{sup 3+} phosphors

    SciTech Connect (OSTI)

    Li, Y.J.; Ma, Y.Y.; Ye, S.; Hu, G.P.; Zhang, Q.Y.

    2014-03-01

    Graphical abstract: - Highlights: • Intense 700–850 nm NIR emissions in MAl{sub 12}O{sub 19} (M = Ca, Sr, Ba):1%Fe{sup 3+} has been obtained. • The NIR emissions can be ascribed to the octahedral Fe{sup 3+} sites. • The site symmetry of Fe{sup 3+} in CA{sub 6} and SA{sub 6} may be lower than that in BA{sub 6}. • The phosphors may be potentially applied in the high-resolution bioimaging. - Abstract: Intense and broad near-infrared (NIR) photoluminescence (PL) peaks locating at 777, 808 and 810 nm is observed for BaAl{sub 12}O{sub 19} (BA{sub 6}):1%Fe{sup 3+}, CaAl{sub 12}O{sub 19} (CA{sub 6}):1%Fe{sup 3+} and SrAl{sub 12}O{sub 19} (SA{sub 6}):1%Fe{sup 3+}, respectively. Electron paramagnetic resonance (EPR) spectra show that Fe{sup 3+} ions substitute for the different types of Al{sup 3+} sites simultaneously. Meanwhile, the luminescence of Fe{sup 3+} in MAl{sub 12}O{sub 19} (M = Ca, Sr and Ba) are ascribed to octahedral Fe{sup 3+}. In addition, the site symmetry of Fe{sup 3+} in CA{sub 6}/SA{sub 6} is lower compared with BA{sub 6}, deduced from the photoluminescence excitation (PLE), EPR and Fourier-transform infrared (FT-IR) spectra. These phosphors can be considered as good candidates for the applications in the field of high-resolution bioimaging.

  20. Synthesis, structures and photocatalytic activities of microcrystalline ABi{sub 2}Nb{sub 2}O{sub 9} (A=Sr, Ba) powders

    SciTech Connect (OSTI)

    Wu, Weiming; Liang, Shijing; Wang, Xiaowei; Bi, Jinhong; Liu, Ping; Wu, Ling

    2011-01-15

    Microcrystalline ABi{sub 2}Nb{sub 2}O{sub 9} (A=Sr, Ba) photocatalysts were successfully synthesized by a citrate complex method. The as-prepared samples were characterized by the X-ray diffraction technique, BET surface area analysis, UV-vis diffuse reflectance spectrum, transmission electron microscopy, X-ray photoelectron spectroscopy and inductively coupled plasma-atomic emission spectrometry. The results indicated that single-phase orthorhombic SrBi{sub 2}Nb{sub 2}O{sub 9} could be obtained after being calcined above 650 {sup o}C, while BaBi{sub 2}Nb{sub 2}O{sub 9} was tetragonal. Based on the diffuse reflectance spectra, the band gaps of the obtained samples were calculated to be around 3.34-3.54 eV. For the photocatalytic redox reaction of methyl orange under UV-light irradiation, SrBi{sub 2}Nb{sub 2}O{sub 9} exhibited higher photocatalytic activity than that of BaBi{sub 2}Nb{sub 2}O{sub 9}. The effects of the crystallinities, BET surface areas and crystal structures of the samples on the photocatalytic activities were discussed in detail. -- Graphical abstract: Aurivillius-type ABi{sub 2}Nb{sub 2}O{sub 9} (A=Sr, Ba) photocatalysts were successfully synthesized by a citrate complex method. SrBi{sub 2}Nb{sub 2}O{sub 9} and BaBi{sub 2}Nb{sub 2}O{sub 9} showed different photocatalytic performances in the redox reaction of methyl orange (MO) under UV-light ({lambda}=254 nm), due to the different crystal structures of ABi{sub 2}Nb{sub 2}O{sub 9} (A=Sr, Ba). Display Omitted

  1. Spin-liquid ground state in the frustrated J1?J2 zigzag chain system BaTb2O4

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aczel, A. A.; Li, L.; Garlea, V. O.; Yan, J. -Q.; Weickert, F.; Zapf, V. S.; Movshovich, R.; Jaime, M.; Baker, P. J.; Keppens, V.; et al

    2015-07-13

    We have investigated polycrystalline samples of the zigzag chain system BaTb2O4 with magnetic susceptibility, heat capacity, neutron powder diffraction, and muon spin relaxation measurements. No magnetic transitions are observed in the bulk measurements, while neutron diffraction reveals the presence of low-temperature, short-range, intrachain magnetic correlations between Tb3+ ions. muSR indicates that these correlations are dynamic, as no signatures of static magnetism are detected by the technique down to 0.095 K. Altogether these findings provide strong evidence for a spin liquid ground state in BaTb2O4.

  2. Spin-liquid ground state in the frustrated J1-J2 zigzag chain system BaTb2O4

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aczel, A. A.; Li, L.; Garlea, V. O.; Yan, J. -Q.; Weickert, F.; Zapf, V. S.; Movshovich, R.; Jaime, M.; Baker, P. J.; Keppens, V.; et al

    2015-07-13

    We have investigated polycrystalline samples of the zigzag chain system BaTb2O4 with magnetic susceptibility, heat capacity, neutron powder diffraction, and muon spin relaxation measurements. No magnetic transitions are observed in the bulk measurements, while neutron diffraction reveals low-temperature, short-range, intrachain magnetic correlations between Tb3+ ions. Muon spin relaxation measurements indicate that these correlations are dynamic, as the technique detects no signatures of static magnetism down to 0.095 K. Altogether these findings provide strong evidence for a spin liquid ground state in BaTb2O4.

  3. Completion Report for Well ER-EC-11 Corrective Action Units 101 and 102: Central and Western Pahute Mesa

    SciTech Connect (OSTI)

    NSTec Environmental Management

    2010-12-01

    Well ER-EC-11 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office, in support of the Nevada Environmental Restoration Project at the Nevada National Security Site (formerly Nevada Test Site), Nye County, Nevada. The well was drilled in September and October 2009 as part of the Pahute Mesa Phase II drilling program. A main objective was to investigate radionuclide migration down-gradient from Well Cluster ER-20-5 and Well ER-20-7 and across the northern Timber Mountain moat structural zone into the area referred to as the Bench, between Pahute Mesa and the Timber Mountain caldera complex. A secondary purpose of the well was to provide detailed hydrogeologic information for the shallow- to intermediate-depth Tertiary volcanic section in the Bench area. This well also provided detailed hydrogeologic information in the Tertiary volcanic section to reduce uncertainties within the Pahute Mesa-Oasis Valley hydrostratigraphic framework model (Bechtel Nevada, 2002). The main 52.1-centimeter hole was drilled to a depth of 507.5 meters and then opened to a diameter of 66.0 centimeters. It was cased with 50.8-centimeter casing to 504.9 meters. The hole diameter was then decreased to 47.0 centimeters, and drilling continued to a total depth of 979.3 meters. It was then cased with 34.0-centimeter casing set at 965.5 meters. The hole diameter was then decreased to 31.1 centimeters and the borehole was drilled to a total depth of 1,264.3 meters. The completion casing string, set to the depth of 1,262.5 meters, consists of 19.4-centimeter stainless-steel casing hanging from 19.4-centimeter carbon-steel casing. The stainless-steel casing has two slotted intervals open to the Tiva Canyon and Topopah Spring aquifers. Four piezometer strings were installed in Well ER-EC-11. A string of carbon-steel 6.0-centimeter tubing with one slotted interval was inserted outside the 50.8-centimeter casing, within the 66.0-centimeter borehole

  4. Strong blue and white photoluminescence emission of BaZrO{sub 3} undoped and lanthanide doped phosphor for light emitting diodes application

    SciTech Connect (OSTI)

    Romero, V.H.; De la Rosa, E.; Salas, P.; Velazquez-Salazar, J.J.

    2012-12-15

    In this paper, we report the obtained strong broadband blue photoluminescence (PL) emission centered at 427 nm for undoped BaZrO{sub 3} observed after 266 nm excitation of submicron crystals prepared by hydrothermal/calcinations method. This emission is enhanced with the introduction of Tm{sup 3+} ions and is stronger than the characteristic PL blue emission of such lanthanide. The proposed mechanism of relaxation for host lattice emission is based on the presence of oxygen vacancies produced during the synthesis process and the charge compensation due to the difference in the electron valence between dopant and substituted ion in the host. Brilliant white light emission with a color coordinate of (x=0.29, y=0.32) was observed by combining the blue PL emission from the host with the green and red PL emission from Tb{sup 3+} and Eu{sup 3+} ions, respectively. The color coordinate can be tuned by changing the ratio between blue, green and red band by changing the concentration of lanthanides. - Graphical abstract: Strong blue emission from undoped BaZrO{sub 3} phosphor and white light emission by doping with Tb{sup 3+} (green) and Eu{sup 3+} (red) after 266 nm excitation. Highlights: Black-Right-Pointing-Pointer Blue emission from BaZrO{sub 3} phosphor. Black-Right-Pointing-Pointer Blue emission enhanced with Tm{sup 3+}. Black-Right-Pointing-Pointer White light from BaZrO{sup 3+} phosphor.

  5. Ba{sub 6}Ge{sub 25}: low-temperature Ge-Ge bond breaking during temperature-induced structure transformation

    SciTech Connect (OSTI)

    Carrillo-Cabrera, Wilder . E-mail: carrillo@cpfs.mpg.de; Borrmann, Horst; Paschen, Silke; Baenitz, Michael; Steglich, Frank; Grin, Yuri

    2005-03-15

    In order to find the optimal conditions for sample preparation of the binary germanide Ba{sub 6}Ge{sub 25}, the germanium-rich part of the Ba-Ge phase diagram was redetermined by means of metallography, X-ray powder diffraction and differential thermal analysis. The temperature behavior of cubic Ba{sub 6}Ge{sub 25} was investigated both on polycrystalline samples and single crystals. The temperature dependence of the lattice parameter exhibits two anomalies at about 180 and 230K, respectively, which are caused by a structure transformation in two steps with hysteresis. Powder (T=10-295K) and single-crystal (T=95-295K) X-ray diffraction studies confirm that the symmetry of Ba{sub 6}Ge{sub 25} (space group P4{sub 1}32) remains unchanged within the entire temperature range. A reconstructive behavior of the structural transformation is observed, involving Ge-Ge bond breaking and barium cation displacements. Some Ge4 type atoms ({approx}28%) are so significantly displaced during cooling that Ge4-Ge6 bonds break and new three-bonded (3b)Ge{sup -} species (electron acceptors) are formed. Consequently, the number of charge carriers is reduced, affecting the physical properties. The reversible bond breaking involved in this process is a typical characteristic of a solid-state chemical reac0010ti.

  6. Single Phase Melt Processed Powellite (Ba,Ca) MoO{sub 4} For The Immobilization Of Mo-Rich Nuclear Waste

    SciTech Connect (OSTI)

    Brinkman, Kyle; Marra, James; Fox, Kevin; Reppert, Jason; Crum, Jarrod; Tang, Ming

    2012-09-17

    Crystalline and glass composite materials are currently being investigated for the immobilization of combined High Level Waste (HLW) streams resulting from potential commercial fuel reprocessing scenarios. Several of these potential waste streams contain elevated levels of transition metal elements such as molybdenum (Mo). Molybdenum has limited solubility in typical silicate glasses used for nuclear waste immobilization. Under certain chemical and controlled cooling conditions, a powellite (Ba,Ca)MoO{sub 4} crystalline structure can be formed by reaction with alkaline earth elements. In this study, single phase BaMoO{sub 4} and CaMoO{sub 4} were formed from carbonate and oxide precursors demonstrating the viability of Mo incorporation into glass, crystalline or glass composite materials by a melt and crystallization process. X-ray diffraction, photoluminescence, and Raman spectroscopy indicated a long range ordered crystalline structure. In-situ electron irradiation studies indicated that both CaMoO{sub 4} and BaMoO{sub 4} powellite phases exhibit radiation stability up to 1000 years at anticipated doses with a crystalline to amorphous transition observed after 1 X 10{sup 13} Gy. Aqueous durability determined from product consistency tests (PCT) showed low normalized release rates for Ba, Ca, and Mo (<0.05 g/m{sup 2}).

  7. Single phase melt processed powellite (Ba,Ca)MoO4 for the immobilization of Mo-rich nuclear waste

    SciTech Connect (OSTI)

    Brinkman, Kyle; Fox, Kevin M.; Marra, James C.; Reppert, Jason; Crum, Jarrod V.; Tang, Ming

    2012-10-02

    Crystalline and glass composite materials are currently being investigated for the immobilization of combined High Level Waste (HLW) streams resulting from potential commercial fuel reprocessing scenarios. Several of these potential waste streams contain elevated levels of transition metal elements such as molybdenum (Mo). Molybdenum has limited solubility in typical silicate glasses used for nuclear waste immobilization. Under certain chemical and controlled cooling conditions, a powellite (Ba,Ca)MoO4 crystalline structure can be formed by reaction with alkaline earth elements. In this study, single phase BaMoO4 and CaMoO4 were formed from carbonate and oxide precursors demonstrating the viability of Mo incorporation into glass, crystalline or glass composite materials by a melt and crystallization process. X-ray diffraction, photoluminescence, and Raman spectroscopy indicated a long range ordered crystalline structure. In situ electron irradiation studies indicated that both CaMoO4 and BaMoO4 powellite phases exhibit radiation stability up to 1000 years at anticipated doses with a crystalline to amorphous transition observed after 1 x 1013 Gy. Aqueous durability determined from product consistency tests (PCT) showed low normalized release rates for Ba, Ca, and Mo (<0.05 g/m2).

  8. Spin dynamics near a putative antiferromagnetic quantum critical point in Cu-substituted BaFe2As2 and its relation to high-temperature superconductivity

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kim, M. G.; Wang, M.; Tucker, G. S.; Valdivia, P. N.; Abernathy, D. L.; Chi, Songxue; Christianson, A. D.; Aczel, A. A.; Hong, T.; Heitmann, T. W.; et al

    2015-12-02

    We present the results of elastic and inelastic neutron scattering measurements on nonsuperconducting Ba(Fe0.957Cu0.043)2As2, a composition close to a quantum critical point between antiferromagnetic (AFM) ordered and paramagnetic phases. By comparing these results with the spin fluctuations in the low-Cu composition as well as the parent compound BaFe2As2 and superconducting Ba(Fe1–xNix)2As2 compounds, we demonstrate that paramagnon-like spin fluctuations are evident in the antiferromagnetically ordered state of Ba(Fe0.957Cu0.043)2As2, which is distinct from the AFM-like spin fluctuations in the superconducting compounds. Our observations suggest that Cu substitution decouples the interaction between quasiparticles and the spin fluctuations. In addition, we show that themore » spin-spin correlation length ξ(T) increases rapidly as the temperature is lowered and find ω/T scaling behavior, the hallmark of quantum criticality, at an antiferromagnetic quantum critical point.« less

  9. First Principles Calculations of Oxygen Vacancy Formation and Migration in Ba1?xSrxCo1?yFeyO3?? Perovskites

    SciTech Connect (OSTI)

    Merkle, Rotraut; Mastrikov, Yuri; Kotomin, Eugene Alexej; Kukla, Maija M.; Maier, Joachim

    2011-12-28

    Based on first principles DFT calculations, we analyze oxygen vacancy formation and migration energies as a function of chemical composition in complex multicomponent (Ba,Sr)(Co,Fe)O3?? perovskites which are candidate materials for SOFC cathodes and permeation membranes. The atomic relaxation, electronic charge redistribution and energies of the transition states of oxygen migration are compared for several perovskites to elucidate the atomistic reason for the exceptionally low migration barrier in Ba0.5Sr0.5Co0.8Fe0.2O3?? that was previously determined experimentally. The critical comparison of Ba1?xSrxCo1?yFeyO3?? perovskites with different cation compositions and arrangements shows that in addition to the geometric constraints the electronic structure plays a considerable role for the height of the oxygen migration barrier in these materials. These findings help understand advantages and limitations of the fast oxygen permeation and exchange properties of Ba0.5Sr0.5Co0.8Fe0.2O3??.

  10. Heterojunction band offsets and dipole formation at BaTiO{sub 3}/SrTiO{sub 3} interfaces

    SciTech Connect (OSTI)

    Balaz, Snjezana; Zeng, Zhaoquan; Brillson, Leonard J.; Department of Physics, The Ohio State University, 191 West Woodruff, Columbus, Ohio 43210

    2013-11-14

    We used a complement of photoemission and cathodoluminescence techniques to measure formation of the BaTiO{sub 3} (BTO) on SrTiO{sub 3} (STO) heterojunction band offset grown monolayer by monolayer by molecular beam epitaxy. X-ray photoemission spectroscopy (XPS) provided core level and valence band edge energies to monitor the valence band offset in-situ as the first few crystalline BTO monolayers formed on the STO substrate. Ultraviolet photoemission spectroscopy (UPS) measured Fermi level positions within the band gap, work functions, and ionization potentials of the growing BTO film. Depth-resolved cathodoluminescence spectroscopy measured energies and densities of interface states at the buried heterojunction. Kraut-based XPS heterojunction band offsets provided evidence for STO/BTO heterojunction linearity, i.e., commutativity and transitivity. In contrast, UPS and XPS revealed a large dipole associated either with local charge transfer or strain-induced polarization within the BTO epilayer.

  11. Ethylene glycol assisted spray pyrolysis for the synthesis of hollow BaFe12O19 spheres

    SciTech Connect (OSTI)

    Xu, X; Park, J; Hong, YK; Lane, AM

    2015-04-01

    Hollow spherical BaFe12O19 particles were synthesized by spray pyrolysis from a solution containing ethylene glycol (EG) and precursors at 1000 degrees C. The effects of EG concentration on particle morphology, crystallinity and magnetic properties were investigated. The hollow spherical particles were found to consist of primary particles, and higher EG concentration led to a bigger primary particle size. EG concentration did not show much effect on the hollow particle size. Better crystallinity and higher magnetic coercivity were obtained with higher EG concentration, which is attributed to further crystallization with the heat produced from EG combustion. Saturation magnetization (emu/g) decreased with increasing EG concentration due to residual carbon from EG incomplete combustion, contributing as a non-magnetic phase to the particles. Published by Elsevier B.V.

  12. Unconventional Electronic Reconstruction in Undoped (Ba,Sr)Fe2As2 Across the Spin Density Wave Transition

    SciTech Connect (OSTI)

    Yi, M.

    2010-06-02

    Through a systematic high-resolution angle-resolved photoemission study of the iron pnictide compounds (Ba,Sr)Fe{sub 2}As{sub 2}, we show that the electronic structures of these compounds are significantly reconstructed across the spin density wave transition, which cannot be described by a simple folding scenario of conventional density wave ordering. Moreover, we find that LDA calculations with an incorporated suppressed magnetic moment of 0.5{mu}{sub B} can match well the details in the reconstructed electronic structure, suggesting that the nature of magnetism in the pnictides is more itinerant than local, while the origin of suppressed magnetic moment remains an important issue for future investigations.

  13. Low-energy planar magnetic defects in BaFe2As2: Nanotwins, twins, antiphase, and domain boundaries

    SciTech Connect (OSTI)

    Khan, Suffian N. [Ames Laboratory; Alam, Aftab [Ames Laboratory; Johnson, Duane D. [Ames Laboratory

    2013-11-27

    In BaFe2As2, structural and magnetic planar defects begin to proliferate below the structural phase transition, affecting descriptions of magnetism and superconductivity. We study, using density-functional theory, the stability and magnetic properties of competing antiphase and domain boundaries, twins and isolated nanotwins (twin nuclei), and spin excitations proposed and/or observed. These nanoscale defects have a very low surface energy (22210 m Jm?2), with twins favorable to the mesoscale. Defects exhibit smaller moments confined near their boundariesmaking a uniform-moment picture inappropriate for long-range magnetic order in real samples. Nanotwins explain features in measured pair distribution functions so should be considered when analyzing scattering data. All these defects can be weakly mobile and/or can have fluctuations that lower assessed ordered moments from longer spatial and/or time averaging and should be considered directly.

  14. Low-energy planar magnetic defects in BaFe2As2: Nanotwins, twins, antiphase, and domain boundaries

    SciTech Connect (OSTI)

    Khan, S. N. [Ames Laboratory] [Ames Laboratory; Alam, A. [Ames Laboratory] [Ames Laboratory; Johnson, Duane D. [University of Illinois, Urbana-Champaign] [University of Illinois, Urbana-Champaign

    2013-01-01

    In BaFe2As2, structural and magnetic planar defects begin to proliferate below the structural phase transition, affecting descriptions of magnetism and superconductivity.We study, using density-functional theory, the stability and magnetic properties of competing antiphase and domain boundaries, twins and isolated nanotwins (twin nuclei), and spin excitations proposed and/or observed. These nanoscale defects have a very low surface energy (22 210 m Jm 2), with twins favorable to the mesoscale. Defects exhibit smaller moments confined near their boundaries making a uniform-moment picture inappropriate for long-range magnetic order in real samples. Nanotwins explain features in measured pair distribution functions so should be considered when analyzing scattering data. All these defects can be weakly mobile and/or can have fluctuations that lower

  15. Specific heat investigation for line nodes in heavily overdoped Ba1-xKxFe2As2

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    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 Ba1-xKxFe2As2 changes from nodeless s-wave near optimally doped, x≈0.4-0.55 and Tc>30 K, to nodal (either d-wave or s-wave) at the pure endpoint, x=1 and Tc<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 Ba1-xKxFe2As2,more » x= 0.91, 0.88, and 0.81. The values for Tcmid are 5.6, 7.2 and 13 K and for Hc2≈ 4.5, 6, and 20 T respectively. Furthermore, the data can be analyzed in a two gap scenario, Δ2/Δ1 ≈ 4, with the magnetic field dependence of γ (=C/T as T→0) showing an anisotropic ‘S-shaped’ behavior vs H, with the suppression of the lower gap by 1 T and γ ≈ H1/2 overall. Although such a non-linear γ 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 Ba1-xKxFe2As2 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 ∝ αT2 in zero field at low temperatures, with α ≤ 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, Δ2, such that the scaling works for fields above 0.25 – 0

  16. Anisotropic Exchange within Decoupled Tetrahedra in the Quantum Breathing Pyrochlore Ba3Yb2Zn5O11

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Rau, J. G.; Wu, L. S.; May, A. F.; Poudel, L.; Winn, B.; Garlea, V. O.; Huq, A.; Whitfield, P.; Taylor, A. E.; Lumsden, M. D.; et al

    2016-06-24

    Tmore » he low energy spin excitation spectrum of the breathing pyrochlore Ba3Yb2Zn5O11 has been investigated with inelastic neutron scattering. Several nearly resolution limited modes with no observable dispersion are observed at 250 mK while, at elevated temperatures, transitions between excited levels become visible. o gain deeper insight, a theoretical model of isolated Yb3+ tetrahedra parametrized by four anisotropic exchange constants is constructed. he model reproduces the inelastic neutron scattering data, specific heat, and magnetic susceptibility with high fidelity. he fitted exchange parameters reveal a Heisenberg antiferromagnet with a very large Dzyaloshinskii-Moriya interaction. Ultimately, using this model, we predict the appearance of an unusual octupolar paramagnet at low temperatures and speculate on the development of inter-tetrahedron correlations.« less

  17. An overview of DANCE: a 4II BaF[2] detector for neutron capture measurements at LANSCE.

    SciTech Connect (OSTI)

    Ullmann, J. L.

    2004-01-01

    The Detector for Advanced Neutron Capture experiments (DANCE) is a 162-element, 4{pi} BaF{sub 2} array designed to make neutron capture cross-section measurements on rare or radioactive targets with masses as little as 1 mg. Accurate capture cross sections are needed in many research areas, including stellar nucleosynthesis, advanced nuclear fuel cycles, waste transmutation, and other applied programs. These cross sections are difficult to calculate accurately and must be measured. Up to now, except for a few long-lived nuclides there are essentially no differential capture measurements on radioactive nuclei. The DANCE array is located at the Lujan Neutron Scattering Center at LANSCE, which is a continuous-spectrum neutron source with useable energies from below thermal to about 100 keV. Data acquisition is done with 320 fast waveform digitizers. The design and initial performance results, including background minimization, will be discussed.

  18. Stripe-like nanoscale structural phase separation in superconducting BaPb1-xBixO3

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    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 BaPb1-xBixO3 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 Tc occurs when the superconducting coherence length matches the width of the partially disordered stripes, implying amore » connection between the structural phase separation and the shape of the superconducting dome.« less

  19. Magnetoelastically coupled structural, magnetic, and superconducting order parameters in BaFe₂(As₁₋xPx)₂

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kuo, H.-H.; Analytis, James G.; Chu, J.-H.; Fernandes, R. M.; Schmalian, J.; Fisher, I. R.

    2012-10-04

    We measure the transport properties of mechanically strained single crystals of BaFe₂(As₁₋xPx)₂ over a wide range of x. The Néel transition is extremely sensitive to stress and this sensitivity increases as optimal doping is approached (doping with the highest superconducting Tc), even though the magnetic transition itself is strongly suppressed. Furthermore, we observe significant changes in the superconducting transition temperature with applied strain, which mirror changes in the composition x. These experiments are a direct illustration of the intimate coupling between different degrees of freedom in iron-based superconductors, revealing the importance of magnetoelastic coupling to the magnetic and superconducting transitionmore » temperatures.« less

  20. Preclinical investigation for developing injectable fiducial markers using a mixture of BaSO{sub 4} and biodegradable polymer for proton therapy

    SciTech Connect (OSTI)

    Ahn, Sang Hee; Gil, Moon Soo; Lee, Doo Sung; Han, Youngyih E-mail: Hee.ro.Park@samsung.com; Park, Hee Chul E-mail: Hee.ro.Park@samsung.com; Yu, Jeong Il; Noh, Jae Myoung; Cho, Jun Sang; Ahn, Sung Hwan; Choi, Doo Ho; Sohn, Jason W.; Kim, Hye Yeong; Shin, Eun Hyuk

    2015-05-15

    Purpose: The aim of this study is to investigate the use of mixture of BaSO{sub 4} and biodegradable polymer as an injectable nonmetallic fiducial marker to reduce artifacts in x-ray images, decrease the absorbed dose distortion in proton therapy, and replace permanent metal markers. Methods: Two samples were made with 90 wt. % polymer phosphate buffer saline (PBS) and 10 wt. % BaSO{sub 4} (B1) or 20 wt. % BaSO{sub 4} (B2). Two animal models (mice and rats) were used. To test the injectability and in vivo gelation, a volume of 200 μl at a pH 5.8 were injected into the Sprague-Dawley rats. After sacrificing the rats over time, the authors checked the gel morphology. Detectability of the markers in the x-ray images was tested for two sizes (diameters of 1 and 2 mm) for B1 and B2. Four samples were injected into BALB/C mice. The polymer mixed with BaSO{sub 4} transform from SOL at 20 °C with a pH of 6.0 to GEL in the living body at 37 °C with a pH of 7.4, so the size of the fiducial marker could be controlled by adjusting the injected volume. The detectability of the BaSO{sub 4} marker was measured in x-ray images of cone beam CT (CBCT), on-board imager [anterior–posterior (AP), lateral], and fluoroscopy (AP, lateral) using a Novalis-TX (Varian Medical Systems, Palo Alto, CA) repeatedly over 4 months. The volume, HU, and artifacts for the markers were measured in the CBCT images. Artifacts were compared to those of gold marker by analyzing the HU distribution. The dose distortion in proton therapy was computed by using a Monte Carlo (MC) code. A cylindrical shaped marker (diameter: 1 or 2 mm, length: 3 mm) made of gold, stainless-steel [304], titanium, and 20 wt. % BaSO{sub 4} was positioned at the center of the spread-out Bragg peak (SOBP) in parallel or perpendicular to the beam entrance. The dose distortion was measured on the depth dose profile across the markers. Results: Transformation to GEL and the biodegradation were verified. All BaSO{sub 4} markers

  1. Carbon-14 immobilization via the Ba(OH)/sub 2/. 8H/sub 2/O process

    SciTech Connect (OSTI)

    Haag, G.L.; Nehls, J.W. Jr.; Young, G.C.

    1983-03-01

    The airborne release of /sup 4/C from varous nuclear facilities has been identified as a potential biohazard due to the long half-life of /sup 14/C (5730 y) and the ease with which it may be assimilated into the biosphere. At ORNL, technology has been developed for the removal and immobilization of this radionuclide. Prior studies have indicated that /sup 14/C will likely exist in the oxidized form as CO/sub 2/ and will contribute slightly to the bulk CO/sub 2/ concentration of the gas stream, which is airlike in nature (approx. 330 ppmv CO/sub 2/). The technology that has been developed utilizes the CO/sub 2/-Ba(OH)/sub 2/.8H/sub 2/O gas-solid reaction with the mode of gas-solid contacting being a fixed bed. The product, BaCO/sub 3/, possesses excellent thermal and chemical stability, prerequisites for the long-term disposal of nuclear wastes. For optimal process operation, studies have indicated that an operating window of adequate size does exist. When operating within the window, high CO/sub 2/ removal efficiency (effluent concentrations < 100 ppbv), high reactant utilization (> 99%), and an acceptable pressure drop across the bed (3 kPa/m at a superficial velocity of 13 cm/s) are possible. This paper addresses three areas of experimental investigation: (1) microscale studies on 150-mg samples to provide information concerning surface properties, kinetics, and equilibrium vapor pressures; (2) macroscale studies on large fixed beds (4.2 kg of reactant) to determine the effects of humidity, temperature, and gas flow rate upon bed pressure drop and CO/sub 2/ breakthrough; and (3) design, construction, and initial operation of a pilot unit capable of continuously processing a 34-m/sup 3//h (20-ft/sup 3//min) air-based gas stream.

  2. NaYF{sub 4}:Er,Yb/Bi{sub 2}MoO{sub 6} core/shell nanocomposite: A highly efficient visible-light-driven photocatalyst utilizing upconversion

    SciTech Connect (OSTI)

    Sun, Yuanyuan; Wang, Wenzhong Sun, Songmei; Zhang, Ling

    2014-04-01

    Highlights: Design and synthesis of NaYF{sub 4}:Er,Yb/Bi{sub 2}MoO{sub 6} based on upconversion. NaYF{sub 4}:Er,Yb/Bi{sub 2}MoO{sub 6} nanocomposite was prepared for the first time. Coreshell structure benefits the properties. Upconversion contributed to the enhanced photocatalytic activity. Helps to understand the functionality of new type photocatalysts. - Abstract: NaYF{sub 4}:Er,Yb/Bi{sub 2}MoO{sub 6} core/shell nanocomposite was designed and prepared for the first time based on upconversion. The products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution TEM (HRTEM), energy dispersive X-ray spectroscopy (EDS) and diffuse reflectance spectra (DRS). The results revealed that the as-synthesized NaYF{sub 4}:Er,Yb/Bi{sub 2}MoO{sub 6} consisted of spheres with a core diameter of about 26 nm and a shell diameter of around 6 nm. The core was upconversion illuminant NaYF{sub 4}:Er,Yb and the shell was Bi{sub 2}MoO{sub 6} around the core, which was confirmed by EDS. The NaYF{sub 4}:Er,Yb/Bi{sub 2}MoO{sub 6} exhibited higher photocatalytic activity for the photodecomposition of Rhodamine B (RhB) under the irradiation of Xe lamp and green light emitting diode (g-LED). The mechanism of the high photocatalytic activity was discussed by photoluminescence spectra (PL), which is mainly attributed to upconversion of NaYF{sub 4}:Er,Yb in the NaYF{sub 4}:Er,Yb/Bi{sub 2}MoO{sub 6} nanocomposite and the coreshell structure.

  3. [beta]-BaV[sub 2](P[sub 2]O[sub 7])[sub 2]: A new polymorph of barium vanadium (III) pyrophosphate characterized by intersecting tunnels

    SciTech Connect (OSTI)

    Hwu, Shiou-Jyh; Carroll, R.I.; Serra, D.L. )

    1994-06-01

    Investigation into the synthesis of reduced vanadium phosphate has led to the formation of a new form of the barium vanadium (III) pyrophosphate compound [beta]-BaV[sub 2](P[sub 2]O[sub 7])[sub 2]. It is a polymorph of the previously known BaV[sub 2](P[sub 2]O[sub 7])[sub 2], which is now labeled as the [alpha]-phase. The title compound crystallizes in the P-1 (No. 2) space group with a = 6.269 (1) [angstrom], b = 7.864 (3) [angstrom], c = 6.1592 (9) [angstrom], [alpha] = 101.34 (2)[degree], [beta] = 105.84 (1)[degree], and [gamma] = 96.51 (2)[degree]. The structure consists of corner-shared VO[sub 6] octahedra and PO[sub 4] tetrahedra that are connected in V-O-P-O-V and V-O-P-O-P-O-V bonding arrangements. This interesting three-dimensional framework is characterized by seven types of intersecting tunnels, three of which are occupied by the barium cation, while the others are empty. It is important to know that one of the empty tunnels has a relatively large window with a minimum diagonal distance of 4.4 [angstrom], which facilitates a possible framework for a lithium ion insertion reaction. The barium atom has a 10-coordination sphere, BaO[sub 10], in which the oxygen atoms can be viewed as forming two intersecting pseudohexagonal planes. [beta]-BaV[sub 2](P[sub 2]O[sub 7])[sub 2] appears to form at a relatively higher temperature than its polymorph, [alpha]-BaV[sub 2](P[sub 2]O[sub 7])[sub 2]. A detailed structural analysis and structural comparison with the [alpha]-phase, as well as a brief comparison with SrV[sub 2](P[sub 2]O[sub 7])[sub 2], are presented.

  4. Novel chemically stable Ba3Ca1.18Nb1.82-xYxO9- proton conductor: improved proton conductivity through tailored cation ordering

    SciTech Connect (OSTI)

    Wang, Siwei; Chen, Yan; Fang, Shumin; Zhang, Lingling; Tang, Ming; An, Ke; Brinkman, Dr. Kyle S.; Chen, Fanglin

    2014-01-01

    Simple perovskite-structured proton conductors encounter significant challenges to simultaneously achieving excellent chemical stability and proton conductivity that are desirable for many important applications in energy conversion and storage. This work demonstrates that Y-doped complex-perovskite-structured Ba3Ca1.18Nb1.82 xYxO9 materials possess both improved proton conductivity and exceptional chemical stability. Neutron powder diffraction refinement revealed a Fm3 m perovskite-structure and increased oxygen vacancy concentration due to the Y doping. High-resolution TEM analysis confirmed the perturbation of the B site cation ordering in the structure for the Ba3Ca1.18Nb1.82 xYxO9 materials. Such combined effects led to improved proton conductivity with a value of 5.3 10 3 S cm 1 at 600 C for Ba3Ca1.18Nb1.52Y0.3O9 (BCNY0.3), a value 2.4 times higher compared with that of the undoped Ba3Ca1.18Nb1.82O9 . The Ba3Ca1.18Nb1.82 xYxO9 materials showed remarkable chemical stability toward water and demonstrated no observable reactions to CO2 exposure. Ionic transport number studies showed that BCNY0.3 had predominantly proton conduction below 600 C. Solid oxide fuel cells using BCNY0.3 as an electrolyte demonstrated cell power output of 103 mW cm 2 at 750 C. These results suggest that a doping strategy that tailors the cation ordering in complex perovskites provides a new direction in the search for novel proton conducting ceramics.

  5. Crystal structure and luminescence properties of a novel red-emitting phosphor BaAlBO{sub 3}F{sub 2}:Eu{sup 3+}

    SciTech Connect (OSTI)

    Chen, Wanping Zhou, Ahong; Liu, Yan; Dai, Xiaoyan; Yang, Xin

    2014-12-15

    A series of novel red-emitting phosphors BaAlBO{sub 3}F{sub 2}:xEu{sup 3+} (0.001≤x≤0.08) were first synthesized via a high temperature solid-state reaction. X-ray diffraction and photoluminescence spectroscopy were used to characterize the crystal structure and photoluminescence properties of the phosphor, respectively. The phosphor can be effectively excited with a 395 nm light, and shows a dominant {sup 5}D{sub 0}−{sup 7}F{sub 2} emission with chromatic coordination of 0.628 and 0.372. The optimal doping concentration is about 0.04. Rietveld refinement results and the luminescence behavior of Eu{sup 3+} indicate that the Eu{sup 3+} ion occupies a C{sub 3} symmetry site, and the host BaAlBO{sub 3}F{sub 2} has a hexagonal structure with P-6 space group. In addition, the phosphor could be a potential candidate as red-emitting phosphor for application in white light-emitting diode. - Graphical abstract: The luminescence behavior and Rietveld refinement of BaAlBO{sub 3}F{sub 2}:Eu{sup 3+} indicate that the red-emitting phosphor has potential application in white LED and the host has a hexagonal structure with P-6 space group. - Highlights: • A novel red-emitting phosphor BaAlBO{sub 3}F{sub 2}:Eu{sup 3+} is first synthesized. • The crystal structure of BaAlBO{sub 3}F{sub 2} is confirmed. • The phosphor shows potential application in white LED.

  6. 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}.

  7. DOE/ER-0442

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

    2 Executive Summary: Atmospheric Radiation Measurement Program Plan ARM Program Plan Foreword In 1978 the Department of Energy initiated the Carbon Dioxide Research Program to address climate change from the increasing concentration of carbon dioxide in the atmosphere. Over the years the Program has studied the many facets of the issue, from the carbon cycle, the climate diagnostics, the vegetative effects, to the societal impacts. The Program is presently the Department's principal entry in the

  8. OoEr

    Office of Legacy Management (LM)

    are as follows: 0 0 0 0 l 0 0 0 0 0 l 0 l l -0 0 0 0 0 0 0 0 0 0 American Machine and Metals, E. Holine, IL .a4 American Steel Foundries, Clncinnatl, OHe3b Bendix Aviation Corp.. ...

  9. DJS CLAIM ER

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

    available original document. L -1- e ' c -2 - MDDC a42 - Physically sodium hydride is a grey or white powder with a density of 0.92 gmscm3. It is extremely active towards water or...

  10. 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

  11. Well ER-6-1 Tracer Test Analysis: Yucca Flat, Nevada Test Site, Nye County, Nevada, Rev. No.: 0

    SciTech Connect (OSTI)

    Greg Ruskauff

    2006-09-01

    The ER-6-1 multiple-well aquifer test-tracer test (MWAT-TT) investigated groundwater flow and transport processes relevant to the transport of radionuclides from sources on the Nevada Test Site (NTS) through the lower carbonate aquifer (LCA) hydrostratigraphic unit (HSU). The LCA, which is present beneath much of the NTS, is the principal aquifer for much of southern Nevada. This aquifer consists mostly of limestone and dolomite, and is pervasively fractured. Groundwater flow in this aquifer is primarily in the fractures, and the hydraulic properties are primarily related to fracture frequency and fracture characteristics (e.g., mineral coatings, aperture, connectivity). The objective of the multiple-well aquifer test (MWAT) was to determine flow and hydraulic characteristics for the LCA in Yucca Flat. The data were used to derive representative flow model and parameter values for the LCA. The items of specific interest are: Hydraulic conductivity; Storage parameters; Dual-porosity behavior; and Fracture flow characteristics. The objective of the tracer transport experiment was to evaluate the transport properties and processes of the LCA and to derive representative transport parameter values for the LCA. The properties of specific interest are: Effective porosity; Matrix diffusion; Longitudinal dispersivity; Adsorption characteristics; and Colloid transport characteristics. These properties substantially control the rate of transport of contaminants in the groundwater system and concentration distributions. To best support modeling at the scale of the corrective action unit (CAU), these properties must be investigated at the field scale. The processes represented by these parameters are affected by in-situ factors that are either difficult to investigate at the laboratory scale or operate at a much larger scale than can be reproduced in the laboratory. Measurements at the field scale provide a better understanding of the effective average parameter values. The

  12. Carbon-14 immobilization via the Ba(OH)/sub 2/8H/sub 2/O process

    SciTech Connect (OSTI)

    Haag, G.L.; Nehls, J.W. Jr.; Young, G.C.

    1982-01-01

    The airborne release of /sup 14/C from various nuclear facilities has been identified as a potential biohazard due to the long half-life of /sup 14/C (5730 yrs) and the ease in which it may be assimilated into the biosphere. At Oak Ridge National Laboratory, technology is under development, as part of the Airborne Waste Management Program, for the removal and immobilization of this radionuclide. Prior studies have indicated that the /sup 14/C will likely exist in the oxidized form as CO/sub 2/ and will contribute slightly to the bulk CO/sub 2/ concentration of the gas stream, which is airlike in nature (approx. 330 ppMv CO/sub 2/). The technology under development utilizes the CO/sub 2/ - Ba(OH)/sub 2/ 8H/sub 2/O gas-solid reaction with the mode of gas-solid contacting being a fixed bed. The product, BaCO/sub 3/, possessing excellent thermal and chemical stability, prerequisites for the long-term disposal of nuclear wastes. For optimal process operation, studies have indicated that an operating window of adequate size does exist. When operating within the window, high CO/sub 2/ removal efficiency (effluent concentrations < 100 ppBv), high reactant utilization (> 99%), and an acceptable pressure drop across the bed (3 kPa/m at 13 cm/s superficial velocity) are possible. This paper will address three areas of experimental investigation. These areas are (1) micro-scale studies on 150-mg samples to provide information concerning surface properties, kinetics, and equilibrium vapor pressures, (2) macro-scale studies on large fixed beds (4.2 kg reactant) to determine the effects of humidity, temperature, and gas flow-rate upon bed pressure drop and CO/sub 2/ breakthrough, and (3) the design, construction, and initial operation of a pilot unit capable of continuously processing a 34 m/sup 3//h (20 ft/sup 3//min) air-based gas stream.

  13. Phytoestrogens in menopausal supplements induce ER-dependent cell proliferation and overcome breast cancer treatment in an in vitro breast cancer model

    SciTech Connect (OSTI)

    Duursen, Majorie B.M. van; Smeets, Evelien E.J.W.; Rijk, Jeroen C.W.; Nijmeijer, Sandra M.; Berg, Martin van den

    2013-06-01

    Breast cancer treatment by the aromatase inhibitor Letrozole (LET) or Selective Estrogen Receptor Modulator Tamoxifen (TAM) can result in the onset of menopausal symptoms. Women often try to relieve these symptoms by taking menopausal supplements containing high levels of phytoestrogens. However, little is known about the potential interaction between these supplements and breast cancer treatment, especially aromatase inhibitors. In this study, interaction of phytoestrogens with the estrogen receptor alpha and TAM action was determined in an ER-reporter gene assay (BG1Luc4E2 cells) and human breast epithelial tumor cells (MCF-7). Potential interactions with aromatase activity and LET were determined in human adrenocorticocarcinoma H295R cells. We also used the previously described H295R/MCF-7 co-culture model to study interactions with steroidogenesis and tumor cell proliferation. In this model, genistein (GEN), 8-prenylnaringenin (8PN) and four commercially available menopausal supplements all induced ER-dependent tumor cell proliferation, which could not be prevented by physiologically relevant LET and 4OH-TAM concentrations. Differences in relative effect potencies between the H295R/MCF-7 co-culture model and ER-activation in BG1Luc4E2 cells, were due to the effects of the phytoestrogens on steroidogenesis. All tested supplements and GEN induced aromatase activity, while 8PN was a strong aromatase inhibitor. Steroidogenic profiles upon GEN and 8PN exposure indicated a strong inhibitory effect on steroidogenesis in H295R cells and H295R/MCF-7 co-cultures. Based on our in vitro data we suggest that menopausal supplement intake during breast cancer treatment should better be avoided, at least until more certainty regarding the safety of supplemental use in breast cancer patients can be provided. - Highlights: Supplements containing phytoestrogens are commonly used by women with breast cancer. Phytoestrogens alter steroidogenesis in a co-culture breast cancer

  14. As you may kn&<' the~de&tment of &~er& (D&j 1s involved'in'a pronram

    Office of Legacy Management (LM)

    As you may kn&<' the~de&tment of &~er& (D&j 1s involved'in'a pronram '. to'chiiracterlze the radjologital cbndif~on of ,sites formerly used byythe . . . ., Manhattan Engineer Dlstrlct (NED) and/or Atomjc Energy Co$n~~lssiqq (AEC); in.. the development of 'nuclear energy.. As part..of this -programi' DOE is 1~ I+ preparing, ,a' series of. brJef~ summaries ,-of .the' history:. of' tho ,#D/AEC~ : : ..; 'i ..relatecl activities and 'Conditions at .thc. sneclfic. sites. The

  15. 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.

  16. Enhance D. C. resistivity of Ba{sub 0.7}Sr{sub 0.3}TiO{sub 3} ceramic by acceptor (Mn) doping

    SciTech Connect (OSTI)

    Sharma, Hakikat Arya, G. S.; Pramar, Kusum; Negi, N. S.

    2015-05-15

    In the present work, we prepared Ba{sub 0.7}Sr{sub 0.3}TiO{sub 3} and Mn (2 and 3 at % on Ti site) doped Ba{sub 0.7}Sr{sub 0.3}TiO{sub 3} ceramic by sol- gel method. The samples were characterized by X-ray diffraction (XRD). The XRD patterns reveled that Mn ions did not change the perovskite structure of BST (70/30). The dielectric measurements proved that dielectric constant decreased with Mn doping. The dc resistivity was studied by using I-V measurements. The dc resistivity of the BST increased with Mn doping, which suppressed the leakage current.

  17. Electron backscatter diffraction analysis of gold nanoparticles on Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7−δ}

    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−δ} 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−δ}. 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.

  18. Giant room-temperature barocaloric effect and pressure-mediated electrocaloric effect in BaTiO{sub 3} single crystal

    SciTech Connect (OSTI)

    Liu, Yang; Wei, Jie; Janolin, Pierre-Eymeric; Infante, Ingrid C.; Dkhil, Brahim E-mail: xlou03@mail.xjtu.edu.cn; Lou, Xiaojie E-mail: xlou03@mail.xjtu.edu.cn

    2014-04-21

    Barocaloric effect in BaTiO{sub 3} single crystal is studied by a thermodynamic phenomenological model. It is demonstrated that a giant barocaloric effect can be achieved near room temperature with an adiabatic temperature change of more than 3 K and a temperature span about 50 K. As expected, the electrocaloric peak can be shifted towards room temperature by pressure. However, a slight reduction of the electrocaloric peak is found in contrast to relaxor ferroelectrics and LiNbO{sub 3}. We believe that our findings could open a potential route by combining the barocaloric effect and pressure-mediated electrocaloric effect in BaTiO{sub 3} single crystal for cooling devices.

  19. A study of electromagnetic characteristics of {sup 124,126,128,130,132,134,136}Ba isotopes performed in the framework of IBA

    SciTech Connect (OSTI)

    Turkan, N.

    2010-01-15

    It was pointed out that the level scheme of the transitional nuclei {sup 124,126,128,130,132,134,136}Ba also can be studied by both characteristics (IBM-1 and IBM-2) of the interacting boson model and an adequate point of the model leading to E2 transitions is therefore confirmed. Most of the {delta}(E2/M1) ratios that are still not known so far are stated and the set of parameters used in these calculations is the best approximation that has been carried out so far. It has turned out that the interacting boson approximation is fairly reliable for the calculation of spectra in the entire set of {sup 124,126,128,130,132,134,136}Ba isotopes.

  20. Electrical conductivity spectra of Sn doped BaTi{sub 0.95}Zr{sub 0.05}O{sub 3}

    SciTech Connect (OSTI)

    Dalal, Biswajit; Sarkar, Babusona; De, S. K.

    2014-05-28

    The alternating current (ac) conductivity spectra of Sn doped BaTi{sub 0.95}Zr{sub 0.05}O{sub 3} prepared by solid state reaction have been studied in the temperature range of 373–473 K. Mixed valency of Sn atoms and the oxygen vacancy controls electrical transport process. The ac conductivity follows Jonscher type power law as a function of frequency. Derived dc conductivity and hopping frequency follow Arrhenius type temperature dependency and have same activation energy. Almost temperature independent nature of frequency exponent indicates that the electrical conduction in Zr and Sn co-doped BaTiO{sub 3} relaxor is quantum mechanical electron tunneling. The conductivity spectra are perfectly scaled using the scaling parameters as dc conductivity and hopping frequency.

  1. Commensurate antiferromagnetic excitations as a signature of the pseudogap in the tetragonal high-Tc cuprate HgBa2CuO4+δ

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chan, M. K.; Dorow, C. J.; Mangin-Thro, L.; Tang, Y.; Ge, Y.; Veit, M. J.; Yu, G.; Zhao, X.; Christianson, A. D.; Park, J. T.; et al

    2016-03-04

    We report that antiferromagnetic correlations have been argued to be the cause of the d-wave superconductivity and the pseudogap phenomena exhibited by the cuprates. Although the antiferromagnetic response in the pseudogap state has been reported for a number of compounds, there exists no information for structurally simple HgBa2CuO4+δ. We report neutron-scattering results for HgBa2CuO4+δ (superconducting transition temperature Tc≈71 K, pseudogap temperature T*≈305 K) that demonstrate the absence of the two most prominent features of the magnetic excitation spectrum of the cuprates: the X-shaped ‘hourglass’ response and the resonance mode in the superconducting state. Instead, the response is Y-shaped, gapped andmore » significantly enhanced below T*, and hence a prominent signature of the pseudogap state.« less

  2. Comparative studies of dipole polarizabilities in Sr{sup +}, Ba{sup +}, and Ra{sup +} and their applications to optical clocks

    SciTech Connect (OSTI)

    Sahoo, B. K.; Timmermans, R. G. E.; Das, B. P.; Mukherjee, D.

    2009-12-15

    Static dipole polarizabilities are calculated in the ground and metastable states of Sr{sup +}, Ba{sup +} and Ra{sup +} using the relativistic coupled-cluster method. Trends of the electron correlation effects are investigated in these atomic ions. We also estimate the Stark and black-body radiation shifts from these results for these systems for the transitions proposed for the optical frequency standards and compare them with available experimental data.

  3. 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.

  4. Syntheses and characterization of energetic compounds constructed from alkaline earth metal cations (Sr and Ba) and 1,2-bis(tetrazol-5-yl)ethane

    SciTech Connect (OSTI)

    Xia Zhengqiang; Chen Sanping; Wei Qing; Qiao Chengfang

    2011-07-15

    Two new energetic compounds, [M(BTE)(H{sub 2}O){sub 5}]{sub n} (M=Sr(1), Ba(2)) [H{sub 2}BTE=1,2-bis(tetrazol-5-yl)ethane], have been hydrothermally synthesized and structurally characterized. Single-crystal X-ray diffraction analyses reveal that they are isomorphous and exhibit 2D (4,4) net framework, generated by 4-connected Sr{sub 2}(H{sub 2}O){sub 10}/Ba{sub 2}(H{sub 2}O){sub 10} SBUs linked up by two independent binding modes of H{sub 2}BTE, and the resulting 2D structure is interconnected by hydrogen-bond and strong face to face {pi}-{pi} stacking interactions between two tetrazole rings to lead to a 3D supramolecular architecture. DSC measurements show that they have significant catalytic effects on thermal decomposition of ammonium perchlorate. Moreover, the photoluminescence properties, thermogravimetric analyses, and flame colors of the as-prepared compounds are also investigated in this paper. - Graphical abstract: Two novel 2D isomorphous alkaline earth metal complexes were assembled by 4-connected Sr{sub 2}(H{sub 2}O){sub 10}/Ba{sub 2}(H{sub 2}O){sub 10} SBUs and two independent binding modes of H{sub 2}BTE ligands, and the catalytic performances toward thermal decomposition of ammonium perchlorate and photoluminescent properties of them were investigated. Highlights: > Two novel alkaline earth energetic coordination polymers have been prepared.{yields} Both structures are layered based on 4-connected Sr{sub 2}(H{sub 2}O){sub 10}/Ba{sub 2}(H{sub 2}O){sub 10} SBUs and two distinct H{sub 2}BTE coordination modes.{yields} The dehydrated products of the compounds possess good thermostability and significant catalytic effects on thermal decomposition of AP.

  5. In situ electric field induced domain evolution in Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}-0.3(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} ferroelectrics

    SciTech Connect (OSTI)

    Zakhozheva, M.; Kleebe, H.-J.; Schmitt, L. A.; Acosta, M.; Rödel, J.; Jo, W.

    2014-09-15

    In this work, the lead-free Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}-0.3(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} piezoelectric ceramic was investigated in situ under an applied electric field by transmission electron microscopy. Significant changes in domain morphology of the studied material have been observed under an applied electric field. During the poling process, the domain configurations disappeared, forming a single-domain state. This multi- to single-domain state transition occurred with the formation of an intermediate nanodomain state. After removing the electric field, domain configurations reappeared. Selected area electron diffraction during electrical poling gave no indication of any structural changes as for example reflection splitting. Rather, a contribution of the extrinsic effect to the piezoelectric response of the Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}-0.3(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} was found to be dominant.

  6. Broad Temperature Pinning Study of 15 mol.% Zr-Added (Gd, Y)-Ba-Cu-O MOCVD Coated Conductors

    SciTech Connect (OSTI)

    Xu, AX; Khatri, N; Liu, YH; Majkic, G; Galstyan, E; Selvamanickam, V; Chen, YM; Lei, CH; Abraimov, D; Hu, XB; Jaroszynski, J; Larbalestier, D

    2015-06-01

    BaZrO3 (BZO) nanocolumns have long been shown to be very effective for raising the pinning force F-p of REBa2Cu3Ox (REBCO, where RE = rare earth) films at high temperatures and recently at low temperatures too. We have successfully incorporated a high density of BZO nanorods into metal organic chemical vapor deposited (MOCVD) REBCO coated conductors via Zr addition. We found that, compared to the 7.5% Zr-added coated conductor, dense BZO nanorod arrays in the 15% Zr-added conductor are effective over the whole temperature range from 77 K down to 4.2 K. We attribute the substantially enhanced J(c) at 30 K to the weak uncorrelated pinning as well as the strong correlated pinning. Meanwhile, by tripling the REBCO layer thickness to similar to 2.8 mu m, the engineering critical current density J(e) at 30 K exceeds J(e) of optimized Nb-Ti wires at 4.2 K.

  7. Geochemistry of Ca, Sr, Ba and Ra sulfates in some deep brines from the Palo Duro basin, Texas

    SciTech Connect (OSTI)

    Langmuir, D.; Melchior, D.

    1985-11-01

    The geochemistry of Ca, Sr, Ba and Ra sulfates in some deep brines from the Palo Duro Basin of north Texas, was studied to define geochemical controls on radionuclides such as /sup 90/Sr and /sup 226/Ra. Published solubility data for gypsum, anhydrite, celestite, barite and RaSO/sub 4/ were first reevaluated, in most cases using the ion interaction approach of Pitzer, to determine solubility products of the sulfates as a function of temperature and pressure. Ionic strengths of the brines were from 2.9 to 4.8 m, their temperatures and pressures up to 40/sup 0/C and 130 bars. Saturation indices of the sulfates were computed with the ion-interaction approach in one brine from the arkosic granite wash facies and four from the carbonate Wolfcamp Formation. All five brines are saturated with respect to gypsum, anhydrite and celestite, and three of the five with respect to barite. All are undersaturated by from 5 to 6 orders of magnitude with respect to pure RaSO/sub 4/. /sup 226/Ra concentrations in the brines, which ranged from 10/sup -11.3/ to 10/sup -12.7/ m, are not controlled by RaSO/sub 4/ solubility or adsorption, but possibly by the solubility of trace Ra solid solutions in sulfates including celestite and barite.

  8. High frequency permeability and permittivity spectra of BiFeO{sub 3}/(CoTi)-BaM ferrite composites

    SciTech Connect (OSTI)

    Peng, Yun; Wu, Xiaohan; Li, Qifan; Yu, Ting; Feng, Zekun; Chen, Zhongyan; Su, Zhijuan; Chen, Yajie; Harris, Vincent G.

    2015-05-07

    Low magnetic loss ferrite composites consisting of Ba(CoTi){sub 1.2}Fe{sub 9.6}O{sub 19} and BiFeO{sub 3} (BFO) ferrite were investigated for permeability, permittivity, and high frequency losses at 10 MHz1?GHz. The phase fraction of BiFeO{sub 3} was quantitatively analyzed by X-ray diffraction measurements. An effective medium approach was employed to predict the effective permeability and permittivity for the ferrite composites, which was found to be in good agreement with experimental data. The experiment demonstrated low magnetic losses (<0.128), modified by BFO phase fraction, while retaining high permeability (?10.86) at 300?MHz. More importantly, the BFO phase resulted in a reduction of magnetic loss by 32%, as BFO phase increased from 2.7 vol.?% to 12.6 vol.?%. The effect of BFO phase on magnetic and dielectric properties revealed great potential for use in the miniaturization of high efficiency antennas.

  9. Absence of strain-mediated magnetoelectric coupling at fully epitaxial Fe/BaTiO{sub 3} interface (invited)

    SciTech Connect (OSTI)

    Radaelli, G. Petti, D.; Cantoni, M.; Rinaldi, C.; Bertacco, R.

    2014-05-07

    Interfacial MagnetoElectric coupling (MEC) at ferroelectric/ferromagnetic interfaces has recently emerged as a promising route to achieve electrical writing of magnetic information in spintronic devices. For the prototypical Fe/BaTiO{sub 3} (BTO) system, various MEC mechanisms have been theoretically predicted. Experimentally, it is well established that using BTO single crystal substrates MEC is dominated by strain-mediated mechanisms. In case of ferromagnetic layers epitaxially grown onto BTO films, instead, no direct evidence for MEC has been provided, apart from the results obtained on tunneling junction sandwiching a BTO tunneling barrier. In this paper, MEC at fully epitaxial Fe/BTO interface is investigated by Magneto-Optical Kerr Effect and magnetoresistance measurements on magnetic tunnel junctions fabricated on BTO. We find no evidence for strain-mediated MEC mechanisms in epitaxial systems, likely due to clamping of BTO to the substrate. Our results indicate that pure electronic MEC is the route of choice to be explored for achieving the electrical writing of information in epitaxial ferromagnet-ferroelectric heterostructures.

  10. Kinetic and Performance Studies of the Regeneration Phase of Model Pt/Ba/Rh NOx Traps for Design and Optimization

    SciTech Connect (OSTI)

    Michael Harold; Vemuri Balakotaiah

    2010-05-31

    In this project a combined experimental and theoretical approach was taken to advance our understanding of lean NOx trap (LNT) technology. Fundamental kinetics studies were carried out of model LNT catalysts containing variable loadings of precious metals (Pt, Rh), and storage components (BaO, CeO{sub 2}). The Temporal Analysis of Products (TAP) reactor provided transient data under well-characterized conditions for both powder and monolith catalysts, enabling the identification of key reaction pathways and estimation of the corresponding kinetic parameters. The performance of model NOx storage and reduction (NSR) monolith catalysts were evaluated in a bench scale NOx trap using synthetic exhaust, with attention placed on the effect of the pulse timing and composition on the instantaneous and cycle-averaged product distributions. From these experiments we formulated a global model that predicts the main spatio-temporal features of the LNT and a mechanistic-based microkinetic models that incorporates a detailed understanding of the chemistry and predicts more detailed selectivity features of the LNT. The NOx trap models were used to determine its ability to simulate bench-scale data and ultimately to evaluate alternative LNT designs and operating strategies. The four-year project led to the training of several doctoral students and the dissemination of the findings as 47 presentations in conferences, catalysis societies, and academic departments as well 23 manuscripts in peer-reviewed journals. A condensed review of NOx storage and reduction was published in an encyclopedia of technology.

  11. Giant magnetocaloric effect in magnetoelectric Eu{sub 1-x}Ba{sub x}TiO{sub 3}

    SciTech Connect (OSTI)

    Rubi, Km; Kumar, Pawan; Maheswar Repaka, D. V.; Chen, Ruofan; Wang, Jian-Sheng; Mahendiran, R.

    2014-01-20

    We report the magnetic entropy change (ΔS{sub m}) in magnetoelectric Eu{sub 1-x}Ba{sub x}TiO{sub 3} for 0.1 ≤ x ≤ 0.9. We find −ΔS{sub m} = 11 (40) J/kg·K in x = 0.1 for a field change of 1 (5) T, respectively, which is the largest value among all Eu-based oxides. ΔS{sub m} arises from the field-induced suppression of the spin entropy of Eu{sup 2+}:4f{sup 7} localized moments. While ∣−ΔS{sub m}∣ decreases with increasing x, ∣−ΔS{sub m}∣ = 6.58 J/kg·K observed in the high spin diluted composition x = 0.9 is larger than that in many manganites. Our results indicate that these magnetoelectrics are potential candidates for cryogenic magnetic refrigeration.

  12. Thermodynamic and nonstoichiometric behavior of the GdBa{sub 2}Cu{sub 3}O{sub x} system.

    SciTech Connect (OSTI)

    Tetenbaum, M.

    1998-09-29

    Electromotive force (EMF) measurements of oxygen fugacities as a function of stoichiometry have been made on the GdBa{sub 2}Cu{sub 3}O{sub x} system in the temperature range {approximately}400-600 C by means of an oxygen titration technique with an yttria-stabilized zirconia electrolyte. Equations for the variation of oxygen partial pressure with composition and temperature have been derived from our EMF measurements. The shape of the 400 C isotherms as a function of oxygen stoichiometry for the Gd and Nd cuprate systems suggests the presence of miscibility gaps at values of x that are higher than those in the YBa{sub 2}Cu{sub 3}O{sub x} system. For a given oxygen stoichiometry, oxygen partial pressures above Gd-123 and Nd-123 cuprate systems are higher (above x = 6.5) than that for the Y-123 system. A thermodynamic assessment and intercomparison of our partial pressure measurements with the results of related measurements will be presented.

  13. Superconducting gap evolution in overdoped BaFe₂(As1-xPx)₂ single crystals through nanocalorimetry

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Campanini, D.; Diao, Z.; Fang, L.; Kwok, W.-K.; Welp, U.; Rydh, A.

    2015-06-18

    We report on specific heat measurements on clean overdoped BaFe₂(As1-xPx)₂ single crystals performed with a high resolution membrane-based nanocalorimeter. A nonzero residual electronic specific heat coefficient at zero temperature γr=C/T|T→0 is seen for all doping compositions, indicating a considerable fraction of the Fermi surface ungapped or having very deep minima. The remaining superconducting electronic specific heat is analyzed through a two-band s-wave α model in order to investigate the gap structure. Close to optimal doping we detect a single zero-temperature gap of Δ₀~5.3 me V, corresponding to Δ₀/kBTc ~ 2.2. Increasing the phosphorus concentration x, the main gap reduces tillmore » a value of Δ₀ ~ 1.9 meV for x = 0.55 and a second weaker gap becomes evident. From the magnetic field effect on γr, all samples however show similar behavior [γr(H) - γr (H = 0)∝ Hn, with n between 0.6 and 0.7]. This indicates that, despite a considerable redistribution of the gap weights, the total degree of gap anisotropy does not change drastically with doping.« less

  14. Resonant Spin Excitation in the High Temperature Superconductor Ba0.6K0.4Fe2As2

    SciTech Connect (OSTI)

    Christianson, Andrew D; Goremychkin, E. A.; Osborn, R.; Rosenkranz, Stephen; Lumsden, Mark D; Malliakas, C.; Todorov, L.; Claus, H.; Chung, D.Y.; Kanatzidis, M.; Bewley, Robert I.; Guidi, T.

    2008-12-18

    A new family of superconductors containing layers of iron arsenide has attracted considerable interest because of their high transition temperatures (T{sub c}), some of which are >50 K, and because of similarities with the high-{sub c} copper oxide superconductors. In both the iron arsenides and the copper oxides, superconductivity arises when an antiferromagnetically ordered phase has been suppressed by chemical doping. A universal feature of the copper oxide superconductors is the existence of a resonant magnetic excitation, localized in both energy and wavevector, within the superconducting phase. This resonance, which has also been observed in several heavy-fermion superconductors is predicted to occur when the sign of the superconducting energy gap takes opposite values on different parts of the Fermi surface, an unusual gap symmetry which implies that the electron pairing interaction is repulsive at short range. Angle-resolved photoelectron spectroscopy shows no evidence of gap anisotropy in the iron arsenides, but such measurements are insensitive to the phase of the gap on separate parts of the Fermi surface. Here we report inelastic neutron scattering observations of a magnetic resonance below T{sub c} in Ba{sub 0.6}K{sub 0.4}Fe{sub 2}As{sub 2}, a phase-sensitive measurement demonstrating that the superconducting energy gap has unconventional symmetry in the iron arsenide superconductors.

  15. Relating electronic and geometric structure of atomic layer deposited BaTiO3 to its electrical properties

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Torgersen, Jan; Acharya, Shinjita; Dadlani, Anup Lal; Petousis, Ioannis; Kim, Yongmin; Trejo, Orlando; Nordlund, Dennis; Prinz, Fritz B.

    2016-03-24

    Atomic layer deposition allows the fabrication of BaTiO3 (BTO) ultrathin films with tunable dielectric properties, which is a promising material for electronic and optical technology. Industrial applicability necessitates a better understanding of their atomic structure and corresponding properties. Through the use of element-specific X-ray absorption near edge structure (XANES) analysis, O K-edge of BTO as a function of cation composition and underlying substrate (RuO2 and SiO2) is revealed. By employing density functional theory and multiple scattering simulations, we analyze the distortions in BTO’s bonding environment captured by the XANES spectra. The spectral weight shifts to lower energy with increasing Timore » content and provides an atomic scale (microscopic) explanation for the increase in leakage current density. Differences in film morphologies in the first few layers near substrate–film interfaces reveal BTO’s homogeneous growth on RuO2 and its distorted growth on SiO2. As a result, this work links structural changes to BTO thin-film properties and provides insight necessary for optimizing future BTO and other ternary metal oxide-based thin-film devices.« less

  16. Magneto-dielectric coupling and transport properties of the ferromagnetic-BaTiO{sub 3} composites

    SciTech Connect (OSTI)

    Kumar, Manish E-mail: mkiitbhu2014@gmail.com; Shankar, S. E-mail: mkiitbhu2014@gmail.com; Dwivedi, G. D.; Anshul, A.; Thakur, O. P.; Ghosh, Anup K. E-mail: mkiitbhu2014@gmail.com

    2015-02-16

    Ferromagnetic and large magnetoresistance (MR) nanocomposites of La{sub 0.67}Sr{sub 0.33}MnO{sub 3}-BaTiO{sub 3} (LSMO-BTO) are synthesized via sol-gel route. The X-ray diffraction confirms the existence of two chemically separated phases in the composites. The maximum MR (35%) was achieved in LSMO-5% BTO (LB5). The coupling between the coexisting phases is observed from the dielectric anomaly at the ferromagnetic transition (T{sub c} = 353 K) for LB5 composition. We observed maximum magnetodielectric effect at T{sub c} of 1.18% in magnitude for LB5 and the effect of magnetic field on other composites was significant. These results are related to the large spin polarization within grains as well as at the grain boundaries and the evidence of variation in dielectric parameters with magnetic field reveal the magnetoelectric coupling in LSMO-BTO nanocomposites.

  17. Neutron diffraction study of the magnetic ordering of the Cu sup ++ spins in Nd sub 1. 5 Ba sub 1. 5 Cu sub 3 O sub 6+x

    SciTech Connect (OSTI)

    Moudden, A.H.; Hennion, B. - Centre d'Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette ); Schweiss, P. - Centre d'Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette Kernforschungszentrum Karlsruhe GmbH . Inst. fuer Nukleare Festkoerperphysik); Gehring, P.M.; Shirane, G. (Brookhaven National Lab., Upton, NY (

    1991-01-01

    Elastic neutron scattering experiments performed on single crystals of Nd{sub 1.5}Ba{sub 1.5}Cu{sub 3}O{sub 6+y} reveal successive antiferromagnetic (AF) ordering of the Cu{sup ++} spins. The as grown single crystals show an AF structure characterized by a Neel temperature T{sub N1} {approximately} 390K and a magnetic wave vector (1/2 1/2 0) referring to the tetragonal structure of NdBa{sub 2}Cu{sub 3}O{sub 6}. As the temperature is lowered below T{sub N2} {approximately} 150K, a spin reorientation develops and a second AF ordering with (1/2 1/2 1/2) wave vector is stabilized. When the samples are oxygenated the tetragonal symmetry and the Neel temperature T{sub N1} remain unchanged, whereas the spin reorientation at T{sub N2} is suppressed. The results indicate that the Nd/Ba substitution increases the stability of the tetragonal structure upon the oxygen content. This may induce new possibilities of local oxygen ordering that favour the presence of holes in the deficient layer.

  18. High mobility field effect transistor based on BaSnO{sub 3} with Al{sub 2}O{sub 3} gate oxide

    SciTech Connect (OSTI)

    Park, Chulkwon; Kim, Useong; Ju, Chan Jong; Park, Ji Sung; Kim, Young Mo; Char, Kookrin

    2014-11-17

    We fabricated an n-type accumulation-mode field effect transistor based on BaSnO{sub 3} transparent perovskite semiconductor, taking advantage of its high mobility and oxygen stability. We used the conventional metal-insulator-semiconductor structures: (In,Sn){sub 2}O{sub 3} as the source, drain, and gate electrodes, Al{sub 2}O{sub 3} as the gate insulator, and La-doped BaSnO{sub 3} as the semiconducting channel. The Al{sub 2}O{sub 3} gate oxide was deposited by atomic layer deposition technique. At room temperature, we achieved the field effect mobility value of 17.8?cm{sup 2}/Vs and the I{sub on}/I{sub off} ratio value higher than 10{sup 5} for V{sub DS}?=?1?V. These values are higher than those previously reported on other perovskite oxides, in spite of the large density of threading dislocations in the BaSnO{sub 3} on SrTiO{sub 3} substrates. However, a relatively large subthreshold swing value was found, which we attribute to the large density of charge traps in the Al{sub 2}O{sub 3} as well as the threading dislocations.

  19. 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 (600C), 119.5 nm (700C), 121.0 nm (800C), 123.1 nm (900C) to 138.4 nm (1000C) 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.

  20. Luminescent properties of Eu{sup 2+}-doped BaGdF{sub 5} glass ceramics a potential blue phosphor for ultra-violet light-emitting diode

    SciTech Connect (OSTI)

    Zhang, Weihuan; Zhang, Yuepin Ouyang, Shaoye; Zhang, Zhixiong; Wang, Qian; Xia, Haiping

    2015-01-14

    Eu{sup 2+} doped transparent oxyfluoride glass ceramics containing BaGdF{sub 5} nanocrystals were successfully fabricated by melt-quenching technique under a reductive atmosphere. The structure of the glass and glass ceramics were investigated by differential scanning calorimetry, X-ray diffraction (XRD), and transmission electron microscopy (TEM). The luminescent properties were investigated by transmission, excitation, and emission spectra. The decay time of the Gd{sup 3+} ions at 312?nm excited with 275?nm were also investigated. The results of XRD and TEM indicated the existence of BaGdF5 nanocrystals in the transparent glass ceramics. The excitation spectra of Eu{sup 2+} doped glass ceramics showed an excellent overlap with the main emission region of an ultraviolet light-emitting diode (UV-LED). Compared with the as-made glass, the emission of glass ceramics is much stronger by a factor of increasing energy transfer efficiency from Gd{sup 3+} to Eu{sup 2+} ions, the energy transfer efficiency from Gd{sup 3+} to Eu{sup 2+} ions was discussed. In addition, the chromaticity coordinates of glass and glass ceramics specimens were also discussed, which indicated that the Eu{sup 2+} doped BaGdF{sub 5} glass ceramics may be used as a potential blue-emitting phosphor for UV-LED.

  1. 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}.

  2. Energy dependence of the spin excitation anisotropy in uniaxial-strained BaFe1.9Ni0.1As2

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Song, Yu; Lu, Xingye; Abernathy, Douglas L.; Tam, David W.; Niedziela, Jennifer L.; Tian, Wei; Si, Qimiao; Dai, Pengcheng; Luo, Huiqian

    2015-11-06

    In this study, we use inelastic neutron scattering to study the temperature and energy dependence of the spin excitation anisotropy in uniaxial-strained electron-doped iron pnictide BaFe1.9Ni0.1As2 near optimal superconductivity (Tc = 20K). Our work has been motivated by the observation of in-plane resistivity anisotropy in the paramagnetic tetragonal phase of electron-underdoped iron pnictides under uniaxial pressure, which has been attributed to a spin-driven Ising-nematic state or orbital ordering. Here we show that the spin excitation anisotropy, a signature of the spin-driven Ising-nematic phase, exists for energies below 60 meV in uniaxial-strained BaFe1.9Ni0.1As2. Since this energy scale is considerably larger thanmore » the energy splitting of the dxz and dyz bands of uniaxial-strained Ba(Fe1–xCox)2As2 near optimal superconductivity, spin Ising-nematic correlations are likely the driving force for the resistivity anisotropy and associated electronic nematic correlations.« less

  3. Direct observation of oxygen-vacancy-enhanced polarization in a SrTiO3-buffered ferroelectric BaTiO3 film on GaAs

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Qiao, Q.; Zhang, Y.; Contreras-Guerrero, Rocio; Droopad, Ravi; Pantelides, S. T.; Pennycook, Stephen J.; Ogut, Serdar; Klie, Robert F.

    2015-11-16

    The integration of functional oxide thin-films on compound semiconductors can lead to a class of reconfigurable spin-based optoelectronic devices if defect-free, fully reversible active layers are stabilized. However, previous first-principles calculations predicted that SrTiO3 thin filmsgrown on Si exhibit pinned ferroelectric behavior that is not switchable, due to the presence of interfacial vacancies. Meanwhile, piezoresponse force microscopy measurements have demonstrated ferroelectricity in BaTiO3 grown on semiconductor substrates. The presence of interfacial oxygen vacancies in such complex-oxide/semiconductor systems remains unexplored, and their effect on ferroelectricity is controversial. We also use a combination of aberration-corrected scanning transmission electron microscopy and first-principles densitymore » functional theory modeling to examine the role of interfacial oxygen vacancies on the ferroelectricpolarization of a BaTiO3 thin filmgrown on GaAs. Moreover, we demonstrate that interfacial oxygen vacancies enhance the polar discontinuity (and thus the single domain, out-of-plane polarization pinning in BaTiO3), and propose that the presence of surface charge screening allows the formation of switchable domains.« less

  4. 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 solgel 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.

  5. Final Technical Report for DOE DE-FG02-05ER54831 "Laboratory Studies of Dynamos."

    SciTech Connect (OSTI)

    Forest, Cary B.

    2014-11-06

    Laboratory Studies of Dynamos: Executive Summary. The self-generation of magnetic fields by astrophysical bodies like planets, stars, accretion disks, galaxies, and even galaxy clusters arises due to a mechanism referred to as a homogeneous dynamo. It is quite simple to demonstrate the generation of a magnetic fi eld from a rotating copper disk coupled with a coil of wire, a device known as the homopolar dynamo. The device works like a magnetic fi eld ampli er with a feedback circuit: the differential rotation of a metal disk past an infinitesimally small seed magnetic field induces currents in the disk which, when coupled to a coil winding, can amplify the field until it becomes strong enough to slow the rotation of the disk. What is remarkable is that the same type of circuit may be achieved in a flowing conducting fluid such as a liquid metal in the case of planetary dynamos or a plasma in the case of astrophysical dynamos. The complexity of describing planetary and stellar dynamos despite their ubiquity and the plethora of observational data from the Earth and the Sun motivates the demonstration of a laboratory homogenous dynamo. To create a homogenous dynamo, one first needs a su fficiently large, fast flow of a highly conducting fluid that the velocity shear in the fluid can bend magnetic field lines. With a high Rm-flow, the magnetic fi eld can be ampli ed by the stretching action provided by di fferential rotation. The other critical ingredient is a flow geometry that provides feedback so that the ampli ed eld reinforces the initial in nitesimal seed field - a mechanism that recreates the feedback provided by the coil of wire in the homopolar dynamo. In the Madison Dynamo Experiment, this combination of magnetic ampli cation and feedback is feasible in the simple geometry of two counter-rotating helical vortices in a 1 meter-diameter spherical vessel lled with liquid sodium. For an optimal helical pitch of the flow the threshold for exciting a dynamo is

  6. A co-precipitation preparation, crystal structure and photoluminescent properties of Er5%:Gd{sub 2}O{sub 3} nanorods

    SciTech Connect (OSTI)

    Boopathi, G. Mohan, R.; Raj, S. Gokul; Kumar, G. Ramesh

    2015-06-24

    An inexpensive preparation method is being reported for obtaining erbium doped gadolinium oxide (Er5%:Gd{sub 2}O{sub 3}) nanoscale rods. The elongated nanoscale systems, as-formed through a co-precipitation process, are characterized by using X-ray powder diffraction (XRD) patterns, scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) mapping, Ultra Violet-visible (UV-vis.) absorption spectroscopy and photoluminescence (PL) spectroscopy. In addition, the Williamson–Hall (W–H) plot is also performed to distinguish the effect of crystalline size-induced broadening and strain-induced broadening at full-width at half-maximum (FWHM) of the XRD profile. The XRD patterns of as-formed and calcined products show that the phase confirmation. As revealed from the SEM micrographs, the morphology of the products show that the rod-like nanoparticles. The EDX micrographs show that the presence of elements in our samples. The band gap values in calcined samples are found to be in the range of 3.569 eV. Upon 230 nm excitation on calcined samples, three broad emission peaks are observed from PL studies. The possible mechanism for the formation of Er5%:Gd{sub 2}O{sub 3} nanorods is briefly discussed.

  7. The breakdown of de Gennes Scaling in TbxEr1-xNi2B2C and its mean field theory explanation

    SciTech Connect (OSTI)

    Gao, Chunwang

    2005-05-01

    The Neel temperatures, T{sub N}, of Tb{sub x}Er{sub 1-x}Ni{sub 2}B{sub 2}C samples have been determined from the temperature dependence of magnetization measurements. A breakdown of the de Gennes scaling of T{sub N} with a clear turning point around x = 0.45 has been observed. The T{sub N} values of Tb{sub x}Er{sub 1-x}Ni{sub 2}B{sub 2}C do not change much within the range of O < x < 0.45 and then, for larger x they increase almost linearly with concentration until T{sub N} = 14.9K is reached for x = 1, TbNi{sub 2}B{sub 2}C. The clear change in the x-dependence of T{sub N} around x = 0.45 can be linked to a change in the local moment ordering direction from transverse to longitudinal, a change which is consistent with recent resonant X-ray scattering data. These features in T{sub N}(x) can be explained using a mean field model.

  8. NdBaFe{sub 2}O{sub 5+w} and steric effect of Nd on valence mixing and ordering of Fe

    SciTech Connect (OSTI)

    Linden, J.; Karen, P.

    2010-11-15

    NdBaFe{sub 2}O{sub 5} above and below Verwey transition is studied by synchrotron X-ray powder diffraction and Moessbauer spectroscopy and compared with GdBaFe{sub 2}O{sub 5} that adopts a higher-symmetry charge-ordered structure typical of the Sm-Ho variants of the title phase. Differences are investigated by Moessbauer spectroscopy accounting for iron valence states at their local magnetic and ionic environments. In the charge-ordered state, the orientation of the electric-field gradient (EFG) versus the internal magnetic field (B) agrees with experiment only when contribution from charges of the ordered d{sub xz} orbitals of Fe{sup 2+} is included, proving thus the orbital ordering. The EFG magnitude indicates that only some 60% of the orbital order occurring in the Sm-Ho variants is achieved in NdBaFe{sub 2}O{sub 5}. The consequent diminishing of the orbit contribution (of opposite sign) to the field B at the Fe{sup 2+} nucleus explains why B is larger than for the Sm-Ho variants. The decreased orbital ordering in NdBaFe{sub 2}O{sub 5} causes a corresponding decrease in charge ordering, which is achieved by decreasing both the amount of the charge-ordered iron states in the sample and their fractional valence separation as seen by the Moessbauer isomer shift. The charge ordering in NdBaFe{sub 2}O{sub 5+w} is more easily suppressed by the oxygen nonstoichiometry (w) than in the Sm-Ho variants. Also the valence mixing into Fe{sup 2.5+} is destabilized by the large size of Nd. The orientation of the EFG around this valence-mixed iron can only be accounted for when the valence-mixing electron is included in the electrostatic ligand field. This proves that the valence mixing occurs between the two iron atoms facing each other across the structural plane of the rare-earth atoms. -- Graphical Abstract: Moessbauer spectrum detects ordering of d{sub xz} orbitals of Fe{sup II}O{sub 5} via the electric-field gradient (EFG) of the orbital, which makes the main component of

  9. Morphology and orientation of β-BaB{sub 2}O{sub 4} crystals patterned by laser in the inside of samarium barium borate glass

    SciTech Connect (OSTI)

    Nishii, Akihito; Shinozaki, Kenji; Honma, Tsuyoshi; Komatsu, Takayuki

    2015-01-15

    Nonlinear optical β-BaB{sub 2}O{sub 4} crystal lines (β-BBO) were patterned in the inside of 8Sm{sub 2}O{sub 3}–42BaO–50B{sub 2}O{sub 3} glass by irradiations of continuous-wave Yb:YVO{sub 4} lasers with a wavelength of 1080 nm (power: P=0.8–1.0 W, scanning speed: S=0.2–2.5 μm/s), in which the laser focal position was moved gradually from the surface to the inside. The morphology, size, and orientation of β-BBO crystals were examined from polarization optical microscope and birefringence imaging observations. It was demonstrated that c-axis oriented β-BBO crystals with long lengths (e.g., 20 mm) were patterned in the inside of the glass. The morphology of β-BBO in the cross-section of lines was a rectangular shape with rounded corners, and the volume of β-BBO formed increased with increasing laser power and with decreasing laser scanning speed. The maximum depth in the inside from the surface for β-BBO patterning increased with increasing laser power, e.g., D{sub max}∼100 μm at P=0.8 W, D{sub max}∼170 μm at P=0.9 W, and D{sub max}∼200 μm at P=1 W. The present study proposes that the laser-induced crystallization opens a new door for applied engineering in glassy solids. - Graphical abstract: This figure shows the POM photographs for β-BaB{sub 2}O{sub 4} crystal lines patterned by cw Yb:YVO{sub 4} fiber laser irradiations with a laser power of P=0.8 W and a laser scanning speed S=2 μm/s in the glass. The laser focal point was moved gradually from the surface into the inside. The results shown in Fig. 1 demonstrate that it is possible to pattern highly oriented β-BaB{sub 2}O{sub 4} crystals even in the inside of glasses. - Highlights: • β-BaB{sub 2}O{sub 4} crystal lines were patterned in the inside of a glass by lasers. • Laser focal position was moved gradually from the surface to the inside. • Birefringence imaging was observed. • Morphology, size, and orientation of crystals were clarified. • Crystal lines with long lengths

  10. Effect of Mn doping on structural and magnetic susceptibility of C-type rare earth nano oxides Er{sub 2?x}Mn{sub x}O{sub 3}

    SciTech Connect (OSTI)

    Heiba, Zein K.; Taif University, Faculty of Science, Physics Department ; Mohamed, Mohamed Bakr; Fuess, H.

    2012-12-15

    Graphical abstract: Display Omitted Highlights: ? Er{sub 2?x}Mn{sub x}O{sub 3} (0.0 ? x ? 0.20) prepared by solgel method. ? The change in lattice parameter is not linear with x due to the change in crystallite size with doping. ? Anomalous concentration dependence is found in magnetic susceptibility. ? The effective magnetic moment ?{sub eff} is found to decrease with composition parameter x. ? Superexchange interactions between Er ions depending on the amount of Mn or Er in different sites. -- Abstract: The manganese doped rare earth oxides Er{sub 2?x}Mn{sub x} O{sub 3} (0.0 ? x ? 0.20) were synthesized by a solgel process and analyzed by X-ray diffraction using Rietveld refinement methods. A single phase solid solution is formed up to x = 0.15 while for x ? 0.2 a manganese oxide phase appears in the diffraction pattern. Preferential cationic distribution between the non-equivalent sites 8b and 24d of space group Ia3{sup } is found for all samples but to a different extent. The octahedral volume and average bond length of Er{sub 1}-O for 8b site decrease while both octahedral volume and bond length of Er{sub 2}-O for 24d site increase. Magnetization measurements were done in the temperature range 5300 K. The effective magnetic moment ?{sub eff} is found to decrease with composition parameter x, except for sample x = 0.05 where the magnetization is enhanced. The Curie-Weiss paramagnetic temperatures indicate antiferromagnetic interaction.

  11. Laser-induced magnetic fields in ICF capsules, Final Report, DE-FG02-08ER85128, Phase 1

    SciTech Connect (OSTI)

    Lindman, Erick L

    2009-11-05

    Laser-induced magnetic fields in ICF capsules Final Report, DE-FG02-08ER85128, Phase 1 E. L. LINDMAN, Otowi Technical Services, Los Alamos, NM. The performance of an inertial-confinement-fusion (ICF) capsule can be improved by inserting a magnetic field into it before compressing it [Kirkpatrick, et al., Fusion Technol. 27, 205 (1995)]. To obtain standoff in an ICF power generator, a method of inserting the field without the use of low-inductance leads attached to the capsule is desired. A mechanism for generating such a field using a laser was discovered in Japan [Sakagami, et al., Phys. Rev. Lett. 42, 839 (1979), Kolodner and Yablonovitch, Phys. Rev. Lett. 43, 1402 (1979)] and studied at Los Alamos in the 1980s [M. A. Yates, et al., Phys. Rev. Lett. 49, 1702 (1982); Forslund and Brackbill, Phys. Rev. Lett. 48, 1614 (1982)]. In this mechanism, a p-polarized laser beam strikes a solid target producing hot electrons that are accelerated away from the target surface by resonant absorption. An electric field is created that returns the hot electrons to the target. But, they do not return to the target along the same trajectory on which they left. The resulting current produces a toroidal magnetic field that was observed to spread over a region outside the hot spot with a radius of a millimeter. No experimental measurements of the magnetic field strength were performed. Estimates from computer simulation suggest that field strengths in the range of 1 to 10 Mega gauss (100 to 1000 Tesla) were obtained outside of the laser spot. To use this mechanism to insert a magnetic field into an ICF capsule, the capsule must be redesigned. In one approach, a central conductor is added, a toroidal gap is cut in the outer wall and the DT fuel is frozen on the inner surface of the capsule. The capsule is dropped into the reaction chamber and struck first with the laser that generates the magnetic field. The laser hot spot is positioned at the center of the toroidal gap. As the

  12. ARM - 2012 AGU Presentations Featuring ARM Data

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

    ... of Clouds ER Lewis, WJ Wiscombe, BA Albrecht, G Bland, CN Flagg, SA Klein, P Kollias, ... Doppler Cloud Radar Observations BA Albrecht, M Fang 4:12 pm, M-West 3006 A54H. Where ...

  13. DOE/SC-ARM-12-020 MAGIC: Marine ARM GPCI Investigation of Clouds

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

    ER Lewis WJ Wiscombe Co-Investigators BA Albrecht GL Bland CN Flagg SA Klein P Kollias G ... Space Flight Center Co-Investigators BA Albrecht, University of Miami GL Bland - NASA ...

  14. Negative to positive magnetoresistance and magnetocaloric effect in Pr0.6Er0.4Al2

    SciTech Connect (OSTI)

    Pathak, Arjun K.; Gschneidner, Jr., K. A.; Pecharsky, V. K.

    2014-10-13

    We report on the magnetic, magnetocaloric and magnetotransport properties of Pr0.6Er0.4Al2. The title compound exhibits a large positive magnetoresistance (MR) for H ≥ 40 kOe and a small but non negligible negative MR for H ≤ 30 kOe. The maximum positive MR reaches 13% at H = 80 kOe. The magnetic entropy and adiabatic temperature changes as functions of temperature each show two anomalies: a broad dome-like maximum below 20 K and a relatively sharp peak at higher temperature. As a result, observed behaviors are unique among other binary and mixed lanthanide compounds.

  15. High-resolution study of 0{sup +} and 2{sup +} excitations in {sup 168}Er with the (p,t) reaction

    SciTech Connect (OSTI)

    Bucurescu, D. [Horia Hulubei National Institute of Physics and Nuclear Engineering, P.O. Box MG-6, R-76900 Bucharest (Romania); Graw, G.; Hertenberger, R. [Sektion Physik, Ludwig Maximilians Universitaet Muenchen, Am Coulombwall 1, D-85748 Garching (Germany); Wirth, H.-F.; Faestermann, T.; Kruecken, R.; Mahgoub, M. [Physik Department, Technische Universitaet Muenchen, D-85748 Garching (Germany); Lo Iudice, N. [Dipartimento di Scienze Fisiche, Universita di Napoli 'Federico II' and Istituto Nazionale di Fisica Nucleare, Monte S Angelo, Via Cintia I-80126 Naples (Italy); Sushkov, A.V.; Shirikova, N.Yu. [Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, RU-141980 Dubna (Russian Federation); Sun, Y. [Department of Physics and Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Department of Physics, Tsinghua University, Beijing 100084 (China); Department of Physics, Xuzhou Normal University, Xuzhou, Jiangsu 221009 (China); Jolie, J.; Brentano, P. von; Braun, N.; Heinze, S.; Moeller, O.; Muecher, D.; Scholl, C. [Institut fuer Kernphysik, Universitaet zu Koeln, D-50937 Cologne (Germany); Casten, R.F.; Meyer, D.A. [Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520-8124 (United States)

    2006-06-15

    Excited states in the deformed nucleus {sup 168}Er have been studied with high-energy resolution, in the (p,t) reaction, with the Munich Q3D spectrograph. A number of 25 excited 0{sup +} states (four tentative) and 63 2{sup +} states have been assigned up to 4.0 MeV excitation energy. This unusually rich characterization of the 0{sup +} and 2{sup +} states in a deformed nucleus, close to a complete level scheme, offers a unique opportunity to check, in detail, models of nuclear structure that incorporate many excitation modes. A comparison of the experimental data is made with two such models: the quasiparticle-phonon model (QPM), and the projected shell model (PSM). The PSM wave functions appear to contain fewer correlations than those of the QPM and than required by the data.

  16. Lifetime of the K{sup pi} = 8{sup -} isomer in the neutron-rich nucleus, {sup 174}Er and N = 106 E1 systematics.

    SciTech Connect (OSTI)

    Dracoulis, G. D.; Lane, G. J.; Kondev, F. G.; Watanabe, H.; Seweryniak, D.; Zhu, S.; Carpenter, M. P.; Chiara, C. J.; Janssens, R. V. F.; Lauritsen, T.; Lister, C. J.; McCutchan, E. A.; Stefanescu, I.; Australian National Univ.; RIKEN; Univ. of Maryland

    2009-06-01

    Chopped-beam techniques and {gamma}-ray spectroscopy with Gammasphere have been used to measure the lifetime of the 1112-keV 8{sup -} isomeric state in {sup 174}Er. The value obtained of {tau} = 5.8(4) s corresponds to a reduced hindrance of f{sub {nu}} = 98 for the 163-keV E1 transition to the 8{sup +} state of the ground-state band, in good agreement with the systematics of the corresponding E1 strengths in the N = 106 isotones. The K-mixing in the 8{sup -} states is calculated in the context of the particle-rotor model and used to extract the underlying reduced hindrances.

  17. Lifetime of the K{sup {pi}}=8{sup -} isomer in the neutron-rich nucleus {sup 174}Er, and N=106 E1 systematics

    SciTech Connect (OSTI)

    Dracoulis, G. D.; Lane, G. J.; Kondev, F. G.; Chiara, C. J.; Watanabe, H.; Seweryniak, D.; Zhu, S.; Carpenter, M. P.; Janssens, R. V. F.; Lauritsen, T.; Lister, C. J.; McCutchan, E. A.; Stefanescu, I.

    2009-06-15

    Chopped-beam techniques and {gamma}-ray spectroscopy with Gammasphere have been used to measure the lifetime of the 1112-keV 8{sup -} isomeric state in {sup 174}Er. The value obtained of {tau}=5.8(4) s corresponds to a reduced hindrance of f{sub {nu}}=98 for the 163-keV E1 transition to the 8{sup +} state of the ground-state band, in good agreement with the systematics of the corresponding E1 strengths in the N=106 isotones. The K-mixing in the 8{sup -} states is calculated in the context of the particle-rotor model and used to extract the underlying reduced hindrances.

  18. Unusually high critical current of clean P-doped BaFe{sub 2}As{sub 2} single crystalline thin film

    SciTech Connect (OSTI)

    Kurth, F. Engelmann, J.; Schultz, L.; Tarantini, C.; Jaroszynski, J.; Grinenko, V.; Reich, E.; Hühne, R.; Hänisch, J.; Mori, Y.; Sakagami, A.; Kawaguchi, T.; Ikuta, H.; Holzapfel, B.; Iida, K.

    2015-02-16

    Microstructurally clean, isovalently P-doped BaFe{sub 2}As{sub 2} (Ba-122) single crystalline thin films have been prepared on MgO (001) substrates by molecular beam epitaxy. These films show a superconducting transition temperature (T{sub c}) of over 30 K although P content is around 0.22, which is lower than the optimal one for single crystals (i.e., 0.33). The enhanced T{sub c} at this doping level is attributed to the in-plane tensile strain. The strained film shows high transport self-field critical current densities (J{sub c}) of over 6 MA/cm{sup 2} at 4.2 K, which are among the highest for Fe based superconductors (FeSCs). In-field J{sub c} exceeds 0.1 MA/cm{sup 2} at μ{sub 0}H=35 T for H‖ab and μ{sub 0}H=18 T for H‖c at 4.2 K, respectively, in spite of moderate upper critical fields compared to other FeSCs with similar T{sub c}. Structural investigations reveal no defects or misoriented grains pointing to strong pinning centers. We relate this unexpected high J{sub c} to a strong enhancement of the vortex core energy at optimal T{sub c}, driven by in-plane strain and doping. These unusually high J{sub c} make P-doped Ba-122 very favorable for high-field magnet applications.

  19. Synthesis and Characterization of Comb and Centipede Multigraft Copolymers PnBA-g-PS with High Molecular Weight Using Miniemulsion Polymerization

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wang, Wenwen; Wang, Weiyu; Lu, Xinyi; Bobade, Sachin; Chen, Jihua; Kang, Nam-goo; Zhang, Qiuyu; Mays, Jimmy

    2014-10-23

    For this study, comb and centipede multigraft copolymers, poly(n-butyl acrylate)-g-polystyrene (PnBA-g-PS) with PnBA backbones and PS side chains, were synthesized via high-vacuum anionic polymerization and miniemulsion polymerization. Single-tailed and double-tailed PS macromonomers were synthesized by anionic polymerization and Steglich esterification. Subsequently, the copolymerization of each macromonomer and nBA was carried out in miniemulsion, and multigraft copolymers were obtained. The latex particles of multigraft copolymers were characterized using dynamic light scattering. The molecular weights of macromonomers and multigraft copolymers were analyzed by size exclusion chromatography. Moreover, the molecular weights and structures of macromonomers were investigated by matrix-assisted laser desorption/ionization time-of-flight massmore » spectrometry and 1H nuclear magnetic resonance spectroscopy. The weight contents of PS in comb and centipede multigraft copolymers were calculated by 1H nuclear magnetic resonance spectroscopy. The thermal properties of multigraft copolymers were characterized by thermogravimetric analysis and differential scanning calorimetry. The microphase separation of multigraft copolymers was observed by atomic force microscopy and transmission electronic microscopy. Rheological measurements showed that comb and centipede multigraft copolymers have elastic properties when the weight content of PS side chains is 26–32 wt %. Centipede multigraft copolymers possess better elastic properties than comb multigraft copolymers with the similar weight content of PS. In conclusion, these findings are similar to previous results on poly(isoprene-g-polystyrene) comb and centipede copolymers made by anionic polymerization.« less

  20. Electron density distribution in BaPb{sub 1-x}Sb{sub x}O{sub 3} superconducting oxides studied by double nuclear magnetic resonance methods

    SciTech Connect (OSTI)

    Piskunov, Yu. V. Ogloblichev, V. V.; Arapova, I. Yu.; Sadykov, A. V.; Gerashchenko, A. P.; Verkhovskii, S. V.

    2011-11-15

    The effect of charge disorder on the formation of an inhomogeneous state of the electron system in the conduction band in BaPb{sub 1-x}Sb{sub x}O{sub 3} superconducting oxides is investigated experimentally by NMR methods. The NMR spectra of {sup 17}O are measured systematically, and the contributions from {sup 17}O atoms with different cation nearest surroundings are identified. It is found that microscopic regions with an elevated spin density of charge carriers are formed within two coordination spheres near antimony ions. Nuclei of the superconducting phase of the oxide (regions with an elevated antimony concentration) microscopically distributed over the sample are detected in compounds with x = 0.25 and 0.33. Experiments in which a double resonance signal of the spin echo of {sup 17}O-{sup 207}Pb and {sup 17}O-{sup 121}Sb are measured in the metal phase of BaPb{sub 1-x}Sb{sub x}O{sub 3} oxides are carried out for the first time. The constants of indirect heteronuclear spin-spin {sup 17}O-{sup 207}Pb interaction are determined as functions of the local Knight shift {sub 207}Ks. The estimates of the constants of the indirect interaction between the nuclei of the nearest neighbors (O-Pb and Pb-Pb atoms) and analysis of evolution of the NMR spectra of {sup 17}O upon a change in the antimony concentration are convincing evidence in favor of the development of a microscopically inhomogeneous state of the electron system in the metal phase of BaPb{sub 1-x}Sb{sub x}O{sub 3} oxides.

  1. Robust antiferromagnetism preventing superconductivity in pressurized (Ba0.61K0.39)Mn2Bi2

    SciTech Connect (OSTI)

    Gu, Dachun; Dai, Xia; Le, Congcong; Sun, Liling; Wu, Qi; Saparov, Bayrammurad; Guo, Jing; Gao, Peiwen; Zhang, Shan; Zhou, Yazhou; Zhang, Chao; Jin, Shifeng; Xiong, Lun; Li, Rui; Li, Yanchun; Li, Xiaodong; Liu, Jing; Sefat, Athena S.; Hu, Jiangping; Zhao, Zhongxian

    2014-12-05

    BaMn2Bi2 possesses an iso-structure of iron pnictide superconductors and similar antiferromagnetic (AFM) ground state to that of cuprates, therefore, it receives much more attention on its properties and is expected to be the parent compound of a new family of superconductors. When doped with potassium (K), BaMn2Bi2 undergoes a transition from an AFM insulator to an AFM metal. Consequently, it is of great interest to suppress the AFM order in the K-doped BaMn2Bi2 with the aim of exploring the potential superconductivity. Here, we report that external pressure up to 35.6 GPa cannot suppress the AFM order in the K-doped BaMn2Bi2 to develop superconductivity in the temperature range of 300 K–1.5 K, but induces a tetragonal (T) to an orthorhombic (OR) phase transition at ~20 GPa. Theoretical calculations for the T and OR phases, on basis of our high-pressure XRD data, indicate that the AFM order is robust in the pressurized Ba0.61K0.39Mn2Bi2. Utlimately, both of our experimental and theoretical results suggest that the robust AFM order essentially prevents the emergence of superconductivity.

  2. Orthorhombic-tetragonal phase coexistence and enhanced piezo-response at room temperature in Zr, Sn, and Hf modified BaTiO{sub 3}

    SciTech Connect (OSTI)

    Kalyani, Ajay Kumar; Brajesh, Kumar; Ranjan, Rajeev; Senyshyn, Anatoliy

    2014-06-23

    The effect of Zr, Hf, and Sn in BaTiO{sub 3} has been investigated at close composition intervals in the dilute concentration limit. Detailed structural analysis by x-ray and neutron powder diffraction revealed that merely 2 mol. % of Zr, Sn, and Hf stabilizes a coexistence of orthorhombic (Amm2) and tetragonal (P4mm) phases at room temperature. As a consequence, all the three systems show substantial enhancement in the longitudinal piezoelectric coefficient (d{sub 33}), with Sn modification exhibiting the highest value ∼425 pC/N.

  3. Formation mechanism and characteristics of lanthanum-doped BaTiO{sub 3} powders and ceramics prepared by the sol–gel process

    SciTech Connect (OSTI)

    Ianculescu, Adelina Carmen; Vasilescu, Catalina Andreea; Crisan, Maria; Raileanu, Malina; Vasile, Bogdan Stefan; Calugaru, Mihai; Crisan, Dorel; Dragan, Nicolae; Curecheriu, Lavinia; Mitoseriu, Liliana

    2015-08-15

    Pure and lanthanum-doped barium titanate nanopowders described by two different formulae, as Ba{sub 1−x}La{sub x}TiO{sub 3}, for lower La concentrations (0 ≤ x ≤ 0.005) and Ba{sub 1−x}La{sub x}Ti{sub 1−x/4}O{sub 3} for higher La concentration (x = 0.025) were prepared by an alkoxide sol–gel method. Single phase compositions were obtained after annealing at 900 °C for 2 h, in air. The increase of the lanthanum content causes structural and morphological changes in the oxide powders, including the evolution of the unit cell from tetragonal toward a cubic symmetry, the particle size decrease and a higher aggregation tendency. SEM investigations of the ceramics sintered at 1300 °C for 4 h indicate significant changes of the microstructural features (strong decrease of the average grain size and increase of the intergranular porosity) with the raise of La amount. Lanthanum addition to barium titanate prepared by sol–gel induces a more significant shift of the Curie temperature toward lower values, than that one reported in literature for ceramics of similar compositions, but processed by the conventional solid state method. The compositions with smaller La amount (x ≤ 0.005) show semiconducting properties at room temperature and high relative dielectric permittivity values, while the undoped ceramics and those doped with higher La content (x = 0.025) are good dielectrics. The ceramic with x = 0.025 exhibits acceptable low losses, a very diffuse ferroelectric–paraelectric transition and Curie temperature closed to the room temperature, being thus susceptible for high tunability applications. - Highlights: • Ba{sub 1−x}La{sub x}TiO{sub 3} (x ≤ 0.005) and Ba{sub 1−x}La{sub x}Ti{sub 1−x/4}O{sub 3} (x = 0.025) were prepared by sol–gel. • Ceramics with x < 0.5 exhibit semiconductor and high dielectric properties. • Ceramic with x = 0.025 exhibits acceptable low losses and diffuse phase transition.

  4. Neutron-scattering evidence for a periodically modulated superconducting phase in the underdoped cuprate La1.905Ba0.095CuO4

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    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 La1.905Ba0.095CuO4. 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 La2-xSrxCuO4 and YBa2Cu3O6+x.

  5. Structural and magnetic properties of transition metal substituted BaFe{sub 2}As{sub 2} compounds studied by x-ray and neutron scattering

    SciTech Connect (OSTI)

    Kim, Min Gyu

    2012-08-28

    The purpose of my dissertation is to understand the structural and magnetic properties of the newly discovered FeAs-based superconductors and the interconnection between superconductivity, antiferromagnetism, and structure. X-ray and neutron scattering techniques are powerful tools to directly observe the structure and magnetism in this system. I used both xray and neutron scattering techniques on di#11;erent transition substituted BaFe2As2 compounds in order to investigate the substitution dependence of structural and magnetic transitions and try to understand the connections between them.

  6. Crystal Growth And Characterization of the Model High-Temperature Superconductor HgBa{sub 2}CuO{sub 4+{delta}}

    SciTech Connect (OSTI)

    Zhao, Xudong; Yu, Guichuan; Cho, Yong-Chan; Chabot-Couture, Guillaume; Barisic, Neven; Bourges, Philippe; Kaneko, Nobuhisa; Li, Yuan; Lu, Li; Motoyama, Eugene M.; Vajk, Owen P.; Greven, Martin; /Stanford U., Appl. Phys. Dept. /SLAC, SSRL /Jilin U. /Stanford U., Phys. Dept. /Saclay /NIST, Wash., D.C.

    2007-03-16

    Since the discovery of high-transition-temperature (T{sub c}) superconductivity in La{sub 2-x}Ba{sub x}CuO{sub 4} in 1986, the study of the lamellar copper oxides has remained at the forefront of condensed matter physics. Apart from their unusually high values of T{sub c}, these materials also exhibit a variety of complex phenomena and phases. This rich behavior is a consequence of the lamellar crystal structures, formed of copper-oxygen sheets separated by charge reservoir layers, and of the strong electron-electron correlations in the copper-oxygen sheets. After two decades of intensive research, which has stimulated many valuable new insights into correlated electron systems in general, there remains a lack of consensus regarding the correct theory for high-T{sub c} superconductivity. The ultimate technological goal of room-temperature superconductivity might only be attained after the development of a deeper understanding of the mercury-based compounds HgBa{sub 2}Ca{sub n-1}Cu{sub n}OI{sub 2n+2+{delta}}, which currently exhibit the highest T{sub c}values. One very important issue in this regard is the role of electronic versus chemical and structural inhomogeneities in these materials, and the associated need to separate material-specific properties from those that are essential to superconductivity. Unfortunately, there has been remarkably little scientific work on the mercury-based compounds because sizable crystals have not been available; quantitative measurements of any kind would be invaluable benchmarks for testing the theories of high-T{sub c} superconductivity. The compounds HgBa{sub 2}Ca{sub n-1}Cu{sub n}OI{sub 2n+2+{delta}} can be viewed as model systems not only because of their record high-T{sub c} values, but also because of their high-symmetry crystal structures. Of particular interest is the simplest member of this materials family, HgBa{sub 2}CuO{sub 4+{delta}} (Hg1201), which possesses only one copper-oxygen sheet per unit cell (n = 1), as

  7. 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; Chang, Hauyee; Takeuchi, Ichiro

    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.

  8. 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.

  9. BA-PIRC

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... Power and Light Tacoma Power FL Natural Gas Assn. Natl. ... focusing on duct system integration, system ... Estar dryer and HPWH - Mini-split retrofits 20 20132014 - ...

  10. Up-conversion luminescent properties of La{sub (0.80−x)}VO{sub 4}:Yb{sub x}, Er{sub 0.20} phosphors

    SciTech Connect (OSTI)

    Choi, Dong Hwa; Kang, Deok Hwa; Yi, Soung Soo; Jang, Kiwan; Jeong, Jung Hyun

    2015-11-15

    Highlights: • A novel green and red emitting LaVO{sub 4}:Yb{sub x}{sup 3+}, Er{sub 0.20}{sup 3+} phosphors were synthesized. • Their structures, luminescent properties have also been investigated. • Major laser transition for Er{sup 3+} ion is {sup 2}H{sub 11/2} → {sup 4}I{sub 15/2} (525 nm). • These results suggest the possibility as photonic devices. - Abstract: Yb{sup 3+}, Er{sup 3+} co-doped LaVO{sub 4} phosphors were synthesized by solid state reaction method. Yb{sup 3+} concentrations were changed from 0.01 to 0.20 mol for the fixed Er{sup 3+} concentration at 0.2 mol. The crystalline structure of samples was investigated by X-ray diffraction (XRD). The composition was investigated by X-ray photoelectron spectroscopy (XPS) analysis. The surface morphology was observed by scanning electron microscope (SEM). The red and green up-conversion emissions were observed in Yb{sup 3+}, Er{sup 3+} co-doped LaVO{sub 4} phosphors under the excitation of 980 nm laser diode. Several emissions in green and red regions of the spectrum were observed near 525 nm, 553 nm and 659 nm radiated by {sup 2}H{sub 11/2} → {sup 4}I{sub 15/2}, {sup 4}S{sub 3/2} → {sup 4}I{sub 15/2}, and {sup 4}F{sub 3/2} → {sup 4}I{sub 15/2} transitions, respectively.

  11. FT-IR and thermoluminescence investigation of P{sub 2}O{sub 5}-BaO-K{sub 2}O glass system

    SciTech Connect (OSTI)

    Ivascu, C.; Timar-Gabor, A.; Cozar, O.

    2013-11-13

    The 0.5P{sub 2}O{sub 5}⋅xBaO⋅(0.5−x)K{sub 2}O glass system (0≤x≤0.5mol%) is investigated by FT-IR and thermoluminescence as a possible dosimetic material. FT-IR spectra show structural network modifications with the composition variations of the studied glasses. The predominant absorption bands are characterized by two broad peaks near 500 cm{sup −1}, two weak peaks around 740 cm{sup −1} and three peaks in the 900–1270 cm{sup −1} region. The shift in the position of the band assigned to asymmetric stretching of PO{sub 2}{sup −} group, υ{sub as}(PO{sub 2}{sup −}) modes from ∼1100 cm{sup −1} to 1085 cm{sup −1} and the decrease in its relative intensity with the increasing of K{sub 2}O content shows a network modifier role of this oxide.. Luminescence investigations show that by adding modifier oxides in the phosphate glass a dose dependent TL signals result upon irradiation. Thus P{sub 2}O{sub 5}–BaO–K{sub 2}O glass system is a possible candidate material for dosimetry in the dose 0 – 50 Gy range.

  12. Two-Step Reactive Aid Sintering of BaZr0.8Y0.2O3-δ Proton-Conducting Ceramics

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wang, Siwei; Chen, Yan; Zhang, Lingling; Ren, Cong; Chen, Fanglin; Brinkman, Kyle S.

    2015-10-14

    Ceramic-based proton conductors enable high-temperature hydrogen economy applications such as hydrogen separation membranes, fuel cells, and steam electrolyzers. BaZr0.8Y0.2O3-δ (BZY) proton-conducting oxide possesses the highest level of proton conductivity reported to date, but poor sinterability hinders its widespread utilization. Here, we report a two-step reactive aid sintering (TRAS) method involving the introduction of BaCO3 and B2O3-Li2O for the preparation of dense BZY ceramics sintered at 1500°C. The resulting BZY samples showed a pure perovskite structure with a dramatic increase in the relative density to 91.5%. In addition, the shrinkage during sintering was improved to 19.3% by a TRAS method asmore » compared to 2.6% by the conventional solid date reaction method. Moreover, the bulk conductivity was improved due to enhanced densification, while the grain boundary conductivity decreased due to the blocking behavior of the sintering aid resulting in a decrease in the total conductivity of the samples.« less

  13. Average and local structure of the Pb-free ferroelectric perovskites (Sr,Sn)TiO3 and (Ba,Ca,Sn)TiO3

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Laurita, Geneva; Page, Katharine; Suzuki, Shoichiro; Seshadri, Ram

    2015-12-16

    The characteristic structural off -centering of Pb2+ in oxides, associated with its 6s2 lone pair, allows it to play a dominant role in polar materials, and makes it a somewhat ubiquitous component of ferroelectrics. In this work, we examine the compounds Sr0.9Sn0.1TiO3 and Ba0.79Ca0.16Sn0.05TiO3 using neutron total scattering techniques with data acquired at di erent temperatures. In these compounds, previously reported as ferroelectrics, Sn2+ appears to display some of the characteristics of Pb2+. We compare the local and long-range structures of the Sn2+-substituted compositions to the unsubstituted parent compounds SrTiO3 and BaTiO3. Lastly, we find that even at these smallmore » substitution levels, the Sn2+ lone pairs drive the local ordering behavior, with the local structure of both compounds more similar to the structure of PbTiO3 rather than the parent compounds.« less

  14. Critical magnetic fields of superconducting aluminum-substituted Ba{sub 8}Si{sub 42}Al{sub 4} clathrate

    SciTech Connect (OSTI)

    Li, Yang Garcia, Jose; Lu, Kejie; Shafiq, Basir; Franco, Giovanni; Lu, Junqiang; Rong, Bo; Chen, Ning; Liu, Yang; Liu, Lihua; Song, Bensheng; Wei, Yuping; Johnson, Shardai S.; Luo, Zhiping; Feng, Zhaosheng

    2015-06-07

    In recent years, efforts have been made to explore the superconductivity of clathrates containing crystalline frameworks of group-IV elements. The superconducting silicon clathrate is unusual in that the structure is dominated by strong sp{sup 3} covalent bonds between silicon atoms, rather than the metallic bonding that is more typical of traditional superconductors. This paper reports on critical magnetic fields of superconducting Al-substituted silicon clathrates, which were investigated by transport, ac susceptibility, and dc magnetization measurements in magnetic fields up to 90 kOe. For the sample Ba{sub 8}Si{sub 42}Al{sub 4}, the critical magnetic fields were measured to be H{sub C1}?=?40.2?Oe and H{sub C2}?=?66.4 kOe. The London penetration depth of 4360? and the coherence length 70? were obtained, whereas the estimated GinzburgLandau parameter of ??=?62 revealed that Ba{sub 8}Si{sub 42}Al{sub 4} is a strong type-II superconductor.

  15. Optoelectronic properties and interband transition of La-doped BaSnO{sub 3} transparent conducting films determined by variable temperature spectral transmittance

    SciTech Connect (OSTI)

    Xing, S. M.; Shan, C.; Jiang, K.; Zhu, J. J.; Li, Y. W.; Hu, Z. G. Chu, J. H.

    2015-03-14

    Perovskite-structured Ba{sub 1?x}La{sub x}SnO{sub 3} (x?=?00.10) films have been directly grown on (0001) sapphire substrates by a sol-gel method. Optical properties and bandgap energy of the films have been investigated by transmittance spectra from 10?K to 450?K. It indicates that these films exhibit a high transmission of more than 80% in the visible region. With increasing temperature, there is a significant bandgap shrinkage of about 0.5?eV for lightly La doping (x???0.04) films. For heavily La doping concentration (x???0.06), the bandgap remains nearly stable with the temperature and La composition. This is due to the fact that the lattice expansion caused by La doping is close to the saturation for the film doped with x?=?0.06. Moreover, temperature dependent conductivity behavior shows a similar pattern, which suggests that the doping concentration of La-doped BaSnO{sub 3} (BLSO) films has a saturated state. The La introduction can modify the Sn 5s-O 2p antibonding state and the nonbonding O 2p orbital, which remarkably affect the electronic bandgap of the BLSO films.

  16. Heat capacity of the site-diluted spin dimer system Ba?(Mn1-xVx)?O?

    SciTech Connect (OSTI)

    Samulon, E. C.; Shapiro, M. C.; Fisher, I. R.

    2011-08-05

    Heat-capacity and susceptibility measurements have been performed on the diluted spin dimer compound Ba?(Mn1-xVx)?O?. The parent compound Ba?Mn?O? is a spin dimer system based on pairs of antiferromagnetically coupled S=1, 3d Mn?? ions such that the zero-field ground state is a product of singlets. Substitution of nonmagnetic S=0, 3d? V?? ions leads to an interacting network of unpaired Mn moments, the low-temperature properties of which are explored in the limit of small concentrations 0?x?0.05. The zero-field heat capacity of this diluted system reveals a progressive removal of magnetic entropy over an extended range of temperatures, with no evidence for a phase transition. The concentration dependence does not conform to expectations for a spin-glass state. Rather, the data suggest a low-temperature random singlet phase, reflecting the hierarchy of exchange energies found in this system.

  17. Determination of anisotropic He2 up to 46 T in (BaO.55K0.45)Fe2As2 single crystals

    SciTech Connect (OSTI)

    Altarawneh, M M [Los Alamos National Laboratory; Collar, K N [Los Alamos National Laboratory; Mielke, C H [Los Alamos National Laboratory; Ni, N [IOWA STATE UNIV; Bud'ko, S [IOWA STATE UNIV.; Canfield, P [IOWA STATE UNIV

    2008-01-01

    The magnetoresistance and the radio frequency penetration depth was measured in the superconductor (Ba{sub 0.55}K{sub 0.45})Fe{sub 2}As{sub 2} under pulsed arid static magnetic fields extending to 46 tesla and down to 20 K. Using these data we are able to infer a H{sub c2}(T), H - T phase diagram, for applied fields parallel and perpendicular to the crystallographic c-axis. The upper critical field anisotropy is moderate, {approx} 3.5 close to T{sub c} , and decreases with the decrease of temperature, reaching {approx} 1.5 at T {approx} 20K. These data and analysis indicate that (i) (Ba{sub 0.55}K{sub 0.45})Fe{sub 2}As{sub 2} is well described by Ginzburg-Landau theory and at 20 K is very close to a dimensional crossover and (ii) H{sub c2}(T = 0) for this compound may easily approach fields of 75 tesla.

  18. Pressure effects on magnetic pair-breaking in Mn- and Eu-substituted BaFe{sub 2}As{sub 2}

    SciTech Connect (OSTI)

    Rosa, P. F. S.; Garitezi, T. M.; Adriano, C.; Urbano, R. R.; Pagliuso, P. G.; Grant, T.; Fisk, Z.; Fernandes, R. M.

    2014-05-07

    We report a combined study of hydrostatic pressure (P ? 25 kbar) and chemical substitution on the magnetic pair-breaking effect in Eu- and Mn-substituted BaFe{sub 2}As{sub 2} single crystals. At ambient pressure, both substitutions suppress the superconducting (SC) transition temperature (T{sub c}) of BaFe{sub 2x}Co{sub x}As{sub 2} samples slightly under the optimally doped region, indicating the presence of a pair-breaking effect. At low pressures, an increase of T{sub c} is observed for all studied compounds followed by an expected decrease at higher pressures. However, in the Eu dilute system, T{sub c} further increases at higher pressure along with a narrowing of the SC transition, suggesting that a pair-breaking mechanism reminiscent of the Eu Kondo single impurity regime is being suppressed by pressure. Furthermore, Electron Spin Resonance (ESR) measurements indicate the presence of Mn{sup 2+} and Eu{sup 2+} local moments and the microscopic parameters extracted from the ESR analysis reveal that the AbrikosovGor'kov expression for magnetic pair-breaking in a conventional sign-preserving superconducting state cannot describe the observed reduction of T{sub c}.

  19. Interfacial dislocations in (111) oriented (Ba0.7Sr0.3)TiO3 films on SrTiO3 single crystal

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    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)TiO3 films grown on (111)-oriented SrTiO3 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 retrievedmore » 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 (Ba0.7Sr0.3)TiO3 films.« less

  20. Development of very high Jc in Ba(Fe1-xCox)2As2 thin films grown on CaF2

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    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(Fe1-xCox)2As2 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, Jc. Moreover, FBS are very sensitive to strain, which induces an important enhancement in critical temperature,Tc, of the material. In this study we demonstrate that strain induced by the substrate can further improve Jc of both single and multilayer films by more than that expected simply due to the increase in Tc. The multilayer deposition of Ba(Fe1-xCox)2As2 on CaF2 increases the pinning force density (Fp=Jc xmore » μ₀H) 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.« less

  1. Systematics of the temperature-dependent interplane resistivity in Ba(Fe1-xMx)₂As₂ (M=Co, Rh, Ni, and Pd)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Tanatar, M. A.; Ni, N.; Thaler, A.; Bud’ko, S. L.; Canfield, P. C.; Prozorov, R.

    2011-07-27

    Temperature-dependent interplane resistivity ρc(T) was measured systematically as a function of transition-metal substitution in the iron-arsenide superconductors Ba(Fe1-xMx)₂As₂, M=Ni, Pd, Rh. The data are compared with the behavior found in Ba(Fe1-xCox)₂As₂, revealing resistive signatures of pseudogap. In all compounds we find resistivity crossover at a characteristic pseudogap temperature T* from nonmetallic to metallic temperature dependence on cooling. Suppression of T* proceeds very similarly in cases of Ni and Pd doping and much faster than in similar cases of Co and Rh doping. In cases of Co and Rh doping an additional minimum in the temperature-dependent ρc emerges for high dopings,more » when superconductivity is completely suppressed. These features are consistent with the existence of a charge gap covering part of the Fermi surface. The part of the Fermi surface affected by this gap is notably larger for Ni- and Pd-doped compositions than in Co- and Rh-doped compounds.« less

  2. Study of Eu{sup 3+} → Eu{sup 2+} reduction in BaAl{sub 2}O{sub 4}:Eu prepared in different gas atmospheres

    SciTech Connect (OSTI)

    Rezende, Marcos V. dos S.; Valerio, Mário E.G.; Jackson, Robert A.

    2015-01-15

    Highlights: • The effect of different gas atmospheres on the Eu reduction process was studied. • The Eu reduction was monitored analyzing XANES region at the Eu L{sub III}-edge. • Hydrogen reducing agent are the most appropriate gas for Eu{sup 2+} stabilization. • Only a part of the Eu ions can be stabilized in the divalent state. • A model of Eu reduction process is proposed. - Abstract: The effect of different gas atmospheres such as H{sub 2}(g), synthetic air, carbon monoxide (CO) and nitrogen (N{sub 2}) on the Eu{sup 3+} → Eu{sup 2+} reduction process during the synthesis of Eu-doped BaAl{sub 2}O{sub 4} was studied using synchrotron radiation. The Eu{sup 3+} → Eu{sup 2+} reduction was monitored analyzing XANES region when the sample are excited at the Eu L{sub III}-edge. The results show that the hydrogen reducing agent are the most appropriate gas for Eu{sup 2+} stabilization in BaAl{sub 2}O{sub 4} and that only a part of the Eu ions can be stabilized in the divalent state. A model of Eu reduction process, based on the incorporation of charge compensation defects, is proposed.

  3. Enhancement in the multiferroic properties of BiFeO{sub 3} by charge compensated aliovalent substitution of Ba and Nb

    SciTech Connect (OSTI)

    Makhdoom, A. R. E-mail: a.r.makhdoom@gmail.com; Rafiq, M. A.; Hasan, M. M.; Akhtar, M. J. E-mail: a.r.makhdoom@gmail.com; Siddique, M.; Iqbal, M.

    2014-03-15

    Polycrystalline ceramics, Bi{sub 1-2x}Ba{sub 2x}Fe{sub 1-x}Nb{sub x}O{sub 3} (x = 0.00–0.15), were synthesized by solid state reactions method. X-ray diffraction data have revealed elimination of impurity phases and an increase in unit cell volume with Ba and Nb substitution. Diffraction peak splitting is found to be suppressed which indicates a decrease in octahedral distortion. The Mössbauer spectra demonstrate the suppression of spiral spin modulation of the magnetic moments resulting in enhanced ferromagnetism with increasing dopant concentration. The leakage current density of the sample with x = 0.10 is found to be greatly reduced up to six orders of magnitude as compared to the undoped sample. Ohmic conduction is found to be dominant mechanism in all the samples, however, undoped sample showed space charge limited conduction in high electric filed region, while the sample with x = 0.15 exhibited grain boundary limited conduction in low electric field region.

  4. Thermoelectric Properties of Au- Containing Type-I Clathrates Ba8AuxGa16-3xGe30+2x

    SciTech Connect (OSTI)

    Ye, Zuxin; Cho, Jung Young; Tessema, Misle M.; Salvador, James R.; Waldo, Richard A.; Yang, Jihui; Wang, Hsin; Cai, Wei; Kirkham, Melanie J; Yang, Jiong; Zhang, Wenqing

    2014-01-01

    Type I clathrates, with compositions based on Ba8Ga16Ge30, are a class of promising thermoelectric materials due to their intrinsically low thermal conductivity. It has been demonstrated previously that the thermoelectric performance can be improved by transition metal substitution of the framework atoms. In this study, the effects of Au substitution for Ga/Ge on thermal and electrical transport properties of type I clathrate compounds have been investigated. Polycrystalline samples with a large range of Au content have been synthesized using conventional solid state techniques with the actual compositions of resulting materials approximately following Zintl-Klemm rules. The charge carrier type changes from electrons (n) to holes (p) as the Au content increases. The Seebeck coefficient (S) and power factor (S2/ where is the electrical resistivity) were improved by Au substitution and the resulting overall thermoelectric properties were enhanced by Au substitution with a thermoelectric figure of merit ZT ~ 0.63 at temperature T = 740 K for the composition Ba8Au5.47Ge39.96. The results presented herein show that Au-containing type I clathrates are promising p-type thermoelectric materials for high temperature applications.

  5. Search for 2νββ decay of Xe136 to the 01+ excited state of Ba136 with the EXO-200 liquid xenon detector

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Albert, J. B.; Auty, D. J.; Barbeau, P. S.; Beck, D.; Belov, V.; Breidenbach, M.; Brunner, T.; Burenkov, A.; Cao, G. F.; Chambers, C.; et al

    2016-03-08

    EXO-200 is a single phase liquid xenon detector designed to search for neutrinoless ββ decay of 136Xe to the ground state of 136Ba. We report here on a search for the two-neutrino ββ decay of 136Xe to the first 0+ excited state, 0+1, of Ba136 based on a 100 kg yr exposure of 136Xe. Using a specialized analysis employing a machine learning algorithm, we obtain a 90% CL half-life sensitivity of 1.7×1024 yr. We find no statistically significant evidence for the 2νββ decay to the excited state resulting in a lower limit of T2ν1/2 (0+ → 0+1) > 6.9 ×1023more » yr at 90% CL. In conclusion, this observed limit is consistent with the estimated half-life of 2.5×1025 yr.« less

  6. Synthesis, structural characterization and properties of SrAl{sub 4−x}Ge{sub x}, BaAl{sub 4−x}Ge{sub x}, and EuAl{sub 4−x}Ge{sub x} (x≈0.3–0.4)—Rare examples of electron-rich phases with the BaAl{sub 4} structure type

    SciTech Connect (OSTI)

    Zhang, Jiliang; Bobev, Svilen

    2013-09-15

    Three solid solutions with the general formula AEAl{sub 4−x}Ge{sub x} (AE=Eu, Sr, Ba; 0.32(1)≤x≤0.41(1)) have been synthesized via the aluminum self-flux method, and their crystal structures have been established from powder and single-crystal X-ray diffraction. They are isotypic and crystallize with the well-known BaAl{sub 4} structure type, adopted by the three AEAl{sub 4} end members. In all structures, Ge substitutes Al only at the 4e Wyckoff site. Results from X-rays photoelectron spectroscopy on EuAl{sub 4−x}Ge{sub x} and EuAl{sub 4} indicate that the interactions between the Eu{sup 2+} cations and the polyanionic framework are enhanced in the Ge-doped structure, despite the slightly elevated Fermi level. Magnetic susceptibility measurements confirm the local moment magnetism, expected for the [Xe]4f{sup 7} electronic configuration of Eu{sup 2+} and suggest strong ferromagnetic interactions at cryogenic temperatures. Resistivity data from single-crystalline samples show differences between the title compounds, implying different bonding characteristics despite the close Debye temperatures. A brief discussion on the observed electron count and homogeneity ranges for AEAl{sub 4−x}Ge{sub x} (AE=Eu, Sr, Ba) is also presented. - Graphical abstract: AEAl{sub 4−x}Ge{sub x} (AE=Eu, Sr, Ba; 0.32(1)≤x≤0.41(1)), three “electron-rich” phases with BaAl{sub 4} structure type have been synthesized and characterized. Display Omitted - Highlights: • Three BaAl{sub 4}-type ternary aluminum germanides have been synthesized with Eu, Sr and Ba. • Eu, Sr and Ba cations have no apparent influence on the solubility of Ge. • The Ge atoms substitute Al on one of two framework sites, thereby strengthening the interactions between the cations and the polyanionic framework.

  7. Q-switched and mode-locked Er{sup 3+}-doped fibre laser using a single-multi-single fibre filter and piezoelectric

    SciTech Connect (OSTI)

    Ji Wang; Yunjun Zhang; Aotuo Dong; Xiaoxin Xu; Youlun Ju; Baoquan Yao

    2014-04-28

    The active Q-switched and passive mode-locked Er{sup 3+}-doped all-fibre laser is presented. The fibre laser centre wavelength is located at 1563 nm and determined by the homemade singlemulti- single (SMS) in-line fibre filter. The laser spectrum width is nearly 0.1 nm. The active Q-switched mechanism relies on the polarisation state control using a piezoelectric to press a segment of passive fibre on the circular cavity. The nonlinear polarisation rotation technology is used to realise the passive self-started modelocked operation. In the passive mode-locked regimes, the output average power is 2.1 mW, repetition frequency is 11.96 MHz, and single pulse energy is 0.18 nJ. With the 100-Hz Q-switched regimes running, the output average power is 1.5 mW. The total Q-switched pulse width is 15 μs, and every Q-switched pulse is made up by several tens of mode-locked peak pulses. The calculated output pulse energy of the Q-switched fibre laser is about 15 μJ, and the energy of every mode-locked pulse is about 64–68 nJ during a Q-switched pulse taking into account the power fraction propagating between pulses. (lasers)

  8. Radiation leukaemogenesis at low doses DE-FG02-05 ER 63947 Final Technical Report 15 May 2005 ?? 14 May 2010

    SciTech Connect (OSTI)

    Simon Bouffler; Christophe Badie; Natalie Brown; Rosemary Finnon

    2010-07-28

    This report provides a full summary of the results obtained under grant DE-FG02-05ER63947, Radiation Leukaemogenesis at low doses. The studies employed an experimental model of radiation leukaemogenesis with the main aim of identifying key events that convert normal cells into leukaemic cells follwoing exposure to radiation. Important aspect of the work was to understand dose-response relationships and time course relationships for leakaemogenis events. The studies performed provided evidence for direct radiation-induced losses of the Sfpi1/PU.1 gene being critical for induction of the disease. No threshold below 0.1 Gy in the induction of the gene losses was observed. The critical cell type in which the myeloid lekaemias arise has been identified and point mutations in the Sfpi1/PU.1 gene are common in leukaemias. The consequences of the genetic losses and mutation have been examined and these provide evidence of a disruption of differentiation in leukaemic cells. Additional pathways to leukaemogenesis have been identified also. Overall the study provides quantitiative data suitable for testing approaches to modelling of leukaemia rosk at low doses.

  9. Developing a Biosensor for Estrogens in Water Samples: Study ofthe Real-time Response of Live Cells of the Estrogen-sensitive YeastStrain RMY/ER-ERE using Fluorescence Microscopy

    SciTech Connect (OSTI)

    Wozei, E.; Hermanowicz, S.W.; Holman, H-Y.N.

    2006-01-01

    Using a fluorescein di-{beta}-d-galactopyranoside (FDG) substrate we show that in live cells of an estrogen-sensitive yeast strain RMY/ER-ERE with human estrogen receptor (ER{alpha}) gene and the lacZ gene which encodes {beta}-galactosidase, the uptake of 17{beta}-estradiol (E2) and the subsequent production of {beta}-galactosidase enzyme occur quite rapidly, with maximal enzyme-catalyzed product formation evident after about 30 min of exposure to E2. This finding which agrees with the well-known rates of enzyme-catalyzed reactions could have implications for shortening the duration of environmental sample screening and monitoring regimes using yeast-based estrogen assays, and the development of biosensors for environmental estrogens to complement quantification methods.

  10. Developing a Biosensor for Estrogens in Water Samples: Study ofthe Real-time Response of Live Cells of the Estrogen-sensitive YeastStrain RMY/ER-ERE using Fluorescence Microscopy

    SciTech Connect (OSTI)

    Wozei, E.; Hermanowicz, S.W.; Holman, H-Y.N.

    2005-07-13

    Using a fluorescein di-{beta}-D-galactopyranoside (FDG) substrate we show that in live cells of an estrogen-sensitive yeast strain RMY/ER-ERE with human estrogen receptor (ER{alpha}) gene and the lacZ gene which encodes {beta}-galactosidase, the uptake of 17 {beta}-estradiol (E2) and the subsequent production of {beta}-galactosidase enzyme occur quite rapidly, with maximal enzyme-catalyzed product formation evident after about 30 minutes of exposure to E2. This finding which agrees with the well-known rates of enzyme-catalyzed reactions could have implications for shortening the duration of environmental sample screening and monitoring regimes using yeast-based estrogen assays, and the development of biosensors for environmental estrogens to complement quantification methods.

  11. Thermoelectric power generator module of 16x16 Bi{sub 2}Te{sub 3} and 0.6%ErAs:(InGaAs){sub 1-x}(InAlAs){sub x} segmented elements

    SciTech Connect (OSTI)

    Zeng Gehong; Bahk, Je-Hyeong; Bowers, John E.; Lu Hong; Gossard, Arthur C.; Singer, Suzanne L.; Majumdar, Arun; Bian, Zhixi; Zebarjadi, Mona; Shakouri, Ali

    2009-08-24

    We report the fabrication and characterization of thermoelectric power generator modules of 16x16 segmented elements consisting of 0.8 mm thick Bi{sub 2}Te{sub 3} and 50 {mu}m thick ErAs:(InGaAs){sub 1-x}(InAlAs){sub x} with 0.6% ErAs by volume. An output power up to 6.3 W was measured when the heat source temperature was at 610 K. The thermoelectric properties of (InGaAs){sub 1-x}(InAlAs){sub x} were characterized from 300 up to 830 K. The finite element modeling shows that the performance of the generator modules can further be enhanced by improving the thermoelectric properties of the element materials, and reducing the electrical and thermal parasitic losses.

  12. Fine tunable red-green upconversion luminescence from glass ceramic containing 5%Er{sup 3+}:NaYF{sub 4} nanocrystals under excitation of two near infrared femtosecond lasers

    SciTech Connect (OSTI)

    Shang, Xiaoying; Cheng, Wenjing; Zhou, Kan; Ma, Jing; Feng, Donghai; Zhang, Shian; Sun, Zhenrong; Jia, Tianqing; Chen, Ping; Qiu, Jianrong

    2014-08-14

    In this paper, we report fine tunable red-green upconversion luminescence of glass ceramic containing 5%Er{sup 3+}: NaYF{sub 4} nanocrystals excited simultaneously by two near infrared femtosecond lasers. When the glass ceramic was irradiated by 800 nm femtosecond laser, weak red emission centered at 670 nm was detected. Bright red light was observed when the fs laser wavelength was tuned to 1490 nm. However, when excited by the two fs lasers simultaneously, the sample emitted bright green light centered at 550 nm, while the red light kept the same intensity. The dependences of the red and the green light intensities on the two pump lasers are much different, which enables us to manipulate the color emission by adjusting the two pump laser intensities, respectively. We present a theoretical model of Er{sup 3+} ions interacting with two fs laser fields, and explain well the experimental results.

  13. Precipitate size refinement by CeO{sub 2} and Y{sub 2}BaCuO{sub 5} additions in directionally solidified YBa{sub 2}Cu{sub 3}O{sub 7}

    SciTech Connect (OSTI)

    Vilalta, N.; Sandiumenge, F.; Pinol, S.; Obradors, X.

    1997-01-01

    Directional solidification of YBa{sub 2}Cu{sub 3}O{sub 7} has been carried out through a Bridgman technique, and the influence of Y{sub 2}BaCuO{sub 5} and CeO{sub 2} additives on the size of Y{sub 2}BaCuO{sub 5} precipitates has been investigated. It is demonstrated in this work that the most efficient procedure to reduce the size of the Y{sub 2}BaCuO{sub 5} precipitates is to increase the concentration of nucleation centers present in the peritectic decomposition of YBa{sub 2}Cu{sub 3}O{sub 7{minus}x}. A small concentration (0.3{endash}1 wt.{percent}) of CeO{sub 2} has a strong influence on the solidification process and on the size of Y{sub 2}BaCuO{sub 5} precipitates. It is shown that when CeO{sub 2} is added, further refinement of the size of precipitates results from the formation of nanometric Y{sub 2}O{sub 3} particles which further enhance the multinucleation effect. We have also observed that coarsening effects are avoided with CeO{sub 2} additives. {copyright} {ital 1997 Materials Research Society.}

  14. Structure and magnetic properties of a new anion-deficient perovskite Pb{sub 2}Ba{sub 2}BiFe{sub 4}ScO{sub 13} with crystallographic shear structure

    SciTech Connect (OSTI)

    Batuk, Maria; Tyablikov, Oleg A.; Tsirlin, Alexander A.; Kazakov, Sergey M.; Rozova, Marina G.; Pokholok, Konstantin V.; Filimonov, Dmitry S.; Antipov, Evgeny V.; Abakumov, Artem M.; Hadermann, Joke

    2013-09-01

    Graphical abstract: - Highlights: Pb{sub 2}Ba{sub 2}BiFe{sub 4}ScO{sub 13} was obtained by solid state synthesis. Its structure was refined from combination of XPD and TEM. It is a new member of the perovskite-related homologous series A{sub n}B{sub n}O{sub 3n?2} with n = 5. Pb{sub 2}Ba{sub 2}BiFe{sub 4}ScO{sub 13} is antiferromagnetically ordered below T{sub N} ?350 K. - Abstract: Pb{sub 2}Ba{sub 2}BiFe{sub 4}ScO{sub 13}, a new n = 5 member of the oxygen-deficient perovskite-based A{sub n}B{sub n}O{sub 3n?2} homologous series, was synthesized using a solid-state method. The crystal structure of Pb{sub 2}Ba{sub 2}BiFe{sub 4}ScO{sub 13} was investigated by a combination of synchrotron X-ray powder diffraction, electron diffraction, high-angle annular dark-field scanning transmission electron microscopy and Mssbauer spectroscopy. At 900 K, it crystallizes in the Ammm space group with the unit cell parameters a = 5.8459(1) ?, b = 4.0426(1) ?, and c = 27.3435(1) ?. In the Pb{sub 2}Ba{sub 2}BiFe{sub 4}ScO{sub 13} structure, quasi-two-dimensional perovskite blocks are periodically interleaved with [1 1 0] (1{sup }01){sub p} crystallographic shear (CS) planes. At the CS planes, the corner-sharing FeO{sub 6} octahedra are transformed into chains of edge-sharing FeO{sub 5} distorted tetragonal pyramids. B-positions of the perovskite blocks between the CS planes are jointly occupied by Fe{sup 3+} and Sc{sup 3+}. The chains of the FeO{sub 5} pyramids and (Fe,Sc)O{sub 6} octahedra delimit six-sided tunnels that are occupied by double columns of cations with a lone electron pair (Pb{sup 2+}). The remaining A-cations (Bi{sup 3+}, Ba{sup 2+}) occupy positions in the perovskite block. According to the magnetic susceptibility measurements, Pb{sub 2}Ba{sub 2}BiFe{sub 4}ScO{sub 13} is antiferromagnetically ordered below T{sub N} ?350 K.

  15. Stripe-like nanoscale structural phase separation in superconducting BaPb1-xBixO3

    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 BaPb1-xBixO3 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 Tc 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.

  16. Structural and dielectric properties of Ba{sub 0.7}Sr{sub 0.3}TiO{sub 3} thin films grown by PLD

    SciTech Connect (OSTI)

    James, K. K.; Satish, B.; Jayaraj, M. K.

    2014-01-28

    Ferroelectric thin films of Ba{sub 0.7}Sr{sub 0.3}TiO{sub 3} (BST) were deposited on Si/SiO{sub 2}/TiO{sub 2}/Pt (PtSi) substrate by pulsed laser deposition (PLD). Crystalline films with perovskite structure were obtained without post-deposition annealing. Phase purity of the deposited films was confirmed by x-ray diffraction. The lowest value of FWHM obtained for the film deposited at oxygen pressure 5.410{sup ?4} mbar and substrate temperature 600C, indicates the high crystallinity of the film. The room temperature dielectric constant at 100 kHz was 85. Butterfly loop, which is the characteristic of ferroelectric materials, was obtained in the regime of ?4 to +4V. The leakage current density was nearly 910{sup ?13} Acm{sup ?2}.

  17. Strain-induced orbital polarization and multiple phase transitions in Ba{sub 2}MnWO{sub 6} from first principles

    SciTech Connect (OSTI)

    Ju, Weiwei; Zhao, Bao; Yang, Zhongqin

    2013-11-28

    Electronic structures of double perovskite Ba{sub 2}MnWO{sub 6} with epitaxial strain are explored by using methods based on density functional theory. An in-plane compressive strain is found not only resulting in a semiconductor-metal transition (SMT), but also altering the magnetic structures, from different kinds of antiferromagnetic to ferromagnetic orders. Orbital polarization and different orbital occupancies of Mn d{sub z{sup 2}} and d{sub x{sup 2}?y{sup 2}} states, induced by the epitaxial strain, are employed to understand the SMT. The rich magnetic phase transitions are rationalized by a magnetic stabilization mechanism. Our results show that many technological applications may be carried out in the material with the control of epitaxial strain.

  18. Physical properties and electronic structure of a new barium titanate suboxide Ba1+?Ti13-?O?? (? = 0.11)

    SciTech Connect (OSTI)

    Rotundu, Costel R.; Jiang, Shan; Deng, Xiaoyu; Qian, Yiting; Khan, Saeed; Hawthorn, David G.; Kotliar, Gabriel; Ni, Ni

    2015-04-01

    The structure, transport, thermodynamic properties, x-ray absorption spectra (XAS), and electronic structure of a new barium titanate suboxide, Ba1+?Ti13-?O?? (? = 0.11), are reported. It is a paramagnetic poor metal with hole carriers dominating the transport. Fermi liquid behavior appears at low temperature. The oxidization state of Ti obtained by the XAS is consistent with the metallic Ti? state. Local density approximation band structure calculations reveal the material is near the Van Hove singularity. The pseudogap behavior in the Ti-d band and the strong hybridization between the Ti-d and O-p orbitals reflect the characteristics of the building blocks of the Ti?? semi-cluster and the TiO? quasi-squares, respectively.

  19. Physical properties and electronic structure of a new barium titanate suboxide Ba{sub 1+?}Ti{sub 13??}O{sub 12} (? = 0.11)

    SciTech Connect (OSTI)

    Rotundu, Costel R.; Jiang, Shan; Ni, Ni; Deng, Xiaoyu; Kotliar, Gabriel; Qian, Yiting; Hawthorn, David G.; Khan, Saeed

    2015-04-01

    The structure, transport, thermodynamic properties, x-ray absorption spectra (XAS), and electronic structure of a new barium titanate suboxide, Ba{sub 1+?}Ti{sub 13??}O{sub 12} (? = 0.11), are reported. It is a paramagnetic poor metal with hole carriers dominating the transport. Fermi liquid behavior appears at low temperature. The oxidization state of Ti obtained by the XAS is consistent with the metallic Ti{sup 2+} state. Local density approximation band structure calculations reveal the material is near the Van Hove singularity. The pseudogap behavior in the Ti-d band and the strong hybridization between the Ti-d and O-p orbitals reflect the characteristics of the building blocks of the Ti{sub 13} semi-cluster and the TiO{sub 4} quasi-squares, respectively.

  20. Effect of proton irradiation on superconductivity in optimally doped BaFe2(As1-xPx)2 single crystals

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Smylie, M. P.; Leroux, M.; Fang, L.; Chmaissem, Omar H.; Claus, H.; Kayani, A.; Snezhko, A.; Welp, U.; Kwok, W. -K.; Mishra, V.; et al

    2016-03-10

    Irradiation with 4 MeV protons was used to systematically introduce defects in single crystals of the iron-arsenide superconductor BaFe2(As1-xPx)2, x = 0.33. The effect of disorder on the low-temperature behavior of the London penetration depth λ(T) and transition temperature Tc was investigated. In nearly optimally doped samples with Tc ~ 29 K, signatures of a superconducting gap with nodes were observed. Contrary to previous reports on electron-irradiated crystals, we do not see a disorder-driven lifting of accidental nodes, and we observe that proton-induced defects are weaker pair breakers than electron-induced defects. Lastly, we attribute our findings to anisotropic electron scatteringmore » caused by proton irradiation defects.« less

  1. Magnetic field induced anisotropy of 139La spin-lattice relaxation rates in stripe ordered La1.875Ba0.125CuO4

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    S. -H. Baek; Gu, G. D.; Utz, Y.; Hucker, M.; Buchner, B.; Grafe, H. -J.

    2015-10-26

    We report 139La nuclear magnetic resonance studies performed on a La1.875Ba0.125CuO4 single crystal. The data show that the structural phase transitions (high-temperature tetragonal → low-temperature orthorhombic → low-temperature tetragonal phase) are of the displacive type in this material. The 139La spin-lattice relaxation rate T–11 sharply upturns at the charge-ordering temperature TCO = 54 K, indicating that charge order triggers the slowing down of spin fluctuations. Detailed temperature and field dependencies of the T–11 below the spin-ordering temperature TSO=40 K reveal the development of enhanced spin fluctuations in the spin-ordered state for H ∥ [001], which are completely suppressed for largemore » fields along the CuO2 planes. Lastly, our results shed light on the unusual spin fluctuations in the charge and spin stripe ordered lanthanum cuprates.« less

  2. Wavelength-dependent optical enhancement of superconducting interlayer coupling in La1.885Ba0.115CuO4

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    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 La1.885Ba0.115CuO4, 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 becomemore » 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.« less

  3. Softening of infrared-active mode of perovskite BaZrO{sub 3} proved by terahertz time-domain spectroscopy

    SciTech Connect (OSTI)

    Helal, M. A.; Mori, T.; Kojima, S.

    2015-05-04

    The low-frequency infrared-active optical modes were studied in a barium zirconate, BaZrO{sub 3}, single crystal with the perovskite structure using terahertz (THz) time-domain spectroscopy (TDS). The real and imaginary parts of the dielectric constants were accurately determined in the frequency range between 0.2 and 2.7 THz. Upon cooling from room temperature to 8 K, the lowest-frequency TO1 mode at 2.32 THz showed a pronounced softening to 1.94 THz. The real part of the dielectric constant at 0.5 THz determined by THz-TDS obeys Barrett's relation, and the existence of a plateau confirms that the quantum effects lead to saturation of the soft mode frequencies of the TO1 and TO2 modes below ≈20 K. This is reminiscent of incipient ferroelectrics with the perovskite structure such as CaTiO{sub 3}.

  4. Nanodomain induced anomalous magnetic and electronic transport properties of LaBaCo{sub 2}O{sub 5.5+?} highly epitaxial thin films

    SciTech Connect (OSTI)

    Ruiz-Zepeda, F.; Ma, C.; Bahena Uribe, D.; Cantu-Valle, J.; Wang, H.; Xu, Xing; Yacaman, M. J.; Ponce, A.; Chen, C.; Lorenz, B.; Jacobson, A. J.; Chu, P. C. W.

    2014-01-14

    A giant magnetoresistance effect (?46% at 20?K under 7?T) and anomalous magnetic properties were found in a highly epitaxial double perovskite LaBaCo{sub 2}O{sub 5.5+?} (LBCO) thin film on (001) MgO. Aberration-corrected Electron Microscopy and related analytical techniques were employed to understand the nature of these unusual physical properties. The as-grown film is epitaxial with the c-axis of the LBCO structure lying in the film plane and with an interface relationship given by (100){sub LBCO} || (001){sub MgO} and [001]{sub LBCO} || [100]{sub MgO} or [010]{sub MgO}. Orderly oxygen vacancies were observed by line profile electron energy loss spectroscopy and by atomic resolution imaging. Especially, oxygen vacancy and nanodomain structures were found to have a crucial effect on the electronic transport and magnetic properties.

  5. Electronic Phase Separation in the Slightly Underdoped Iron Pnictide Superconductor Ba{sub 1-x}K{sub x}Fe{sub 2}As{sub 2}

    SciTech Connect (OSTI)

    Park, J. T.; Inosov, D. S.; Sun, G. L.; Haug, D.; Dinnebier, R.; Boris, A. V.; Yang, Xiaoping; Lin, C. T.; Keimer, B.; Hinkov, V.; Niedermayer, Ch.; Christensen, N. B.; Drew, A. J.; Schulz, L.; Shapoval, T.; Wolff, U.; Neu, V.

    2009-03-20

    Here we present a combined study of the slightly underdoped novel pnictide superconductor Ba{sub 1-x}K{sub x}Fe{sub 2}As{sub 2} by means of x-ray powder diffraction, neutron scattering, muon-spin rotation ({mu}SR), and magnetic force microscopy (MFM). Static antiferromagnetic order sets in below T{sub m}{approx_equal}70 K as inferred from the neutron scattering and zero-field-{mu}SR data. Transverse-field {mu}SR below T{sub c} shows a coexistence of magnetically ordered and nonmagnetic states, which is also confirmed by MFM imaging. We explain such coexistence by electronic phase separation into antiferromagnetic and superconducting- or normal-state regions on a lateral scale of several tens of nanometers. Our findings indicate that such mesoscopic phase separation can be considered an intrinsic property of some iron pnictide superconductors.

  6. Physical properties and electronic structure of a new barium titanate suboxide Ba1+δTi13-δO₁₂ (δ = 0.11)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Rotundu, Costel R.; Jiang, Shan; Deng, Xiaoyu; Qian, Yiting; Khan, Saeed; Hawthorn, David G.; Kotliar, Gabriel; Ni, Ni

    2015-04-01

    The structure, transport, thermodynamic properties, x-ray absorption spectra (XAS), and electronic structure of a new barium titanate suboxide, Ba1+δTi13-δO₁₂ (δ = 0.11), are reported. It is a paramagnetic poor metal with hole carriers dominating the transport. Fermi liquid behavior appears at low temperature. The oxidization state of Ti obtained by the XAS is consistent with the metallic Ti²⁺ state. Local density approximation band structure calculations reveal the material is near the Van Hove singularity. The pseudogap behavior in the Ti-d band and the strong hybridization between the Ti-d and O-p orbitals reflect the characteristics of the building blocks of themore » Ti₁₃ semi-cluster and the TiO₄ quasi-squares, respectively.« less

  7. Induced Ti magnetization at La0.7Sr0.3MnO3 and BaTiO3 interfaces

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Liu, Yaohua; Tornos, J.; te Velthuis, S. G. E.; Freeland, J. W.; Zhou, H.; Steadman, P.; Bencok, P.; Leon, C.; Santamaria, J.

    2016-04-01

    In artificial multiferroics hybrids consisting of ferromagnetic La0.7Sr0.3MnO3 (LSMO) and ferroelectric BaTiO3 epitaxial layers, net Ti moments are found from polarized resonant soft x-ray reflectivity and absorption. Moreover, the Ti dichroic reflectivity follows the Mn signal during the magnetization reversal, indicating exchange coupling between the Ti and Mn ions. But, the Ti dichroic reflectivity shows stronger temperature dependence than the Mn dichroic signal. Besides a reduced ferromagnetic exchange coupling in the interfacial LSMO layer, this may also be attributed to a weak Ti-Mn exchange coupling that is insufficient to overcome the thermal energy at elevated temperatures.

  8. Physical properties and electronic structure of a new barium titanate suboxide Ba1+δTi13-δO₁₂ (δ = 0.11)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Rotundu, Costel R.; Jiang, Shan; Deng, Xiaoyu; Qian, Yiting; Khan, Saeed; Hawthorn, David G.; Kotliar, Gabriel; Ni, Ni

    2015-04-01

    The structure, transport, thermodynamic properties, x-ray absorption spectra (XAS), and electronic structure of a new barium titanate suboxide, Ba1+δTi13-δO₁₂ (δ = 0.11), are reported. It is a paramagnetic poor metal with hole carriers dominating the transport. Fermi liquid behavior appears at low temperature. The oxidization state of Ti obtained by the XAS is consistent with the metallic Ti²⁺ state. Local density approximation band structure calculations reveal the material is near the Van Hove singularity. The pseudogap behavior in the Ti-d band and the strong hybridization between the Ti-d and O-p orbitals reflect the characteristics of the building blocks of themore »Ti₁₃ semi-cluster and the TiO₄ quasi-squares, respectively.« less

  9. Photoluminescence and compositional-structural properties of ion-beam sputter deposited Er-doped TiO{sub 2−x}N{sub x} films: Their potential as a temperature sensor

    SciTech Connect (OSTI)

    Scoca, D. Morales, M.; Merlo, R.; Alvarez, F.; Zanatta, A. R.

    2015-05-28

    Er-doped TiO{sub 2−x}N{sub x} films were grown by Ar{sup +} ion-beam sputtering a Ti + Er target under different N{sub 2} + O{sub 2} high-purity atmospheres. The compositional-structural properties of the samples were investigated after thermal annealing the films up to 1000 °C under a flow of oxygen. Sample characterization included x-ray photoelectron spectroscopy, grazing incidence x-ray diffraction, Raman scattering, and photoluminescence experiments. According to the experimental data, both composition and atomic structure of the samples were very sensitive to the growth conditions and annealing temperature. In the as-deposited form, the N-rich TiO{sub 2−x}N{sub x} films presented TiN crystallites and no photoluminescence. As the thermal treatments proceed, the films were transformed into TiO{sub 2} and Er{sup 3+}-related light emission were observed in the visible and near-infrared ranges at room-temperature. Whereas the development of TiO{sub 2} occurred due to the insertion-diffusion of oxygen in the films, light emission originated because of optical bandgap widening and/or structural-chemical variations in the vicinity of the Er{sup 3+} ions. Finally, the photoluminescence results in the visible range suggested the potential of the present samples in producing an optically based temperature sensor in the ∼150–500 K range.

  10. Analysis of Hydraulic Responses from the ER-6-1 Multiple-Well Aquifer Test, Yucca Flat FY 2004 Testing Program, Nevada Test Site, Nye County, Nevada, Rev. No.: 0

    SciTech Connect (OSTI)

    Greg Ruskauff

    2005-06-01

    This report documents the interpretation and analysis of the hydraulic data collected for the Fiscal Year (FY) 2004 Multiple-Well Aquifer Test-Tracer Test (MWAT-TT) conducted at the ER-6-1 Well Cluster in Yucca Flat Corrective Action Unit (CAU) 97, on the Nevada Test Site (NTS). The MWAT-TT was performed to investigate CAU-scale groundwater flow and transport processes related to the transport of radionuclides from sources on the NTS through the Lower Carbonate Aquifer (LCA) Hydrostratigraphic Unit (HSU). The ER-6-1 MWAT-TT was planned and executed by contractor participants for the Underground Test Area (UGTA) Project of the Environmental Restoration (ER) program of the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office (NNSA/NSO). Participants included Stoller-Navarro Joint Venture (SNJV), the Environmental Engineering Services Contractor; Bechtel Nevada (BN); the Desert Research Institute (DRI); Los Alamos National Laboratory; and the University of Nevada, Las Vegas-Harry Reid Center. The SNJV team consists of the S.M. Stoller Corporation, Navarro Research and Engineering, Battelle Memorial Institute, INTERA Inc., and Weston Solutions, Inc. The MWAT-TT was implemented according to the ''Underground Test Area Project, ER-6-1 Multi-Well Aquifer Test - Tracer Test Plan'' (SNJV, 2004a) issued in April 2004. The objective of the aquifer test was to determine flow processes and local hydraulic properties for the LCA through long-term constant-rate pumping at the well cluster. This objective was to be achieved in conjunction with detailed sampling of the composite tracer breakthrough at the pumping well, as well as with depth-specific sampling and logging at multiple wells, to provide information for the depth-discrete analysis of formation hydraulic properties, particularly with regard to fracture properties.

  11. Magnetic properties and magnetocaloric effect in the RCu{sub 2}Si{sub 2} and RCu{sub 2}Ge{sub 2} (R = Ho, Er) compounds

    SciTech Connect (OSTI)

    Mo, Zhao-Jun; Shen, Jun E-mail: tangcc@hebut.edu.cn; Wu, Jian-Feng; Yan, Li-Qin; Wang, Li-Chen; Sun, Ji-rong; Shen, Bao-Gen; Gao, Xin-Qiang; Tang, Cheng-Chun E-mail: tangcc@hebut.edu.cn

    2014-02-21

    The magnetic properties and magnetocaloric effect (MCE) in RCu{sub 2}Si{sub 2} and RCu{sub 2}Ge{sub 2} (R = Ho, Er) compounds have been investigated. All these compounds possess an antiferromagnetic (AFM)-paramagnetic (PM) transition around their respective Neel temperatures. The RCu{sub 2}Si{sub 2} compounds undergo spin-glassy behavior above Neel temperature. Furthermore, a field-induced metamagnetic transition from AFM to ferromagnetic (FM) states is observed in these compounds. The calculated magnetic entropy changes show that all RCu{sub 2}Si{sub 2} and RCu{sub 2}Ge{sub 2} (R = Ho, Er) compounds, especially, ErCu{sub 2}Si{sub 2} exhibits large MCEs with no thermal hysteresis and magnetic hysteresis loss. The value of −ΔS{sub M}{sup max} reaches 22.8 J/Kg K for magnetic field changes from 0 to 5 T. In particular, for field changes of 1 and 2 T, the giant reversible magnetic entropy changes −ΔS{sub M}{sup max} are 8.3 and 15.8 J/kg K at 2.5 K, which is lower than the boiling point of helium. The low-field giant magnetic entropy change, together with ignorable thermal hysteresis and field hysteresis loss of ErCu{sub 2}Si{sub 2} compound is expected to have effective applications in low temperature magnetic refrigeration.

  12. Dielectric behavior of samarium-doped BaZr{sub 0.2}Ti{sub 0.8}O{sub 3} ceramics

    SciTech Connect (OSTI)

    Li, Yuanliang; Wang, Ranran; Ma, Xuegang; Li, Zhongqiu; Sang, Rongli; Qu, Yuanfang

    2014-01-01

    Graphical abstract: - Highlights: We investigate dielectric properties and phase transition of Sm{sup 3+}-doped BaZr{sub 0.2}Ti{sub 0.8}O{sub 3} ceramics. The additive amount of Sm{sub 2}O{sub 3} can greatly affect the dielectric properties. The materials undergo a diffuse type ferroelectric phase transition. There is an alternation of substitution preference of Sm{sup 3+} ion for the host cations in perovskite lattice. - Abstract: The dielectric properties and phase transition of Sm{sup 3+}-doped BaZr{sub 0.2}Ti{sub 0.8}O{sub 3} (BZT20) ceramics were investigated. Room temperature X-ray diffraction study suggested that the compositions had single-phase cubic symmetry. Microstructure studies showed that the grain size decreased and that the Sm{sub 2}O{sub 3} amount markedly affected the dielectric properties of BZT20. A dielectric constant of 5700 at 0.2 mol% Sm{sub 2}O{sub 3} and a dissipation factor of only 0.0011 at 2 mol% Sm{sub 2}O{sub 3} were observed, indicating that BZT20 had significant potential applications. Moreover, the dielectric constant, dissipation factor, phase-transition temperature, and maximum dielectric constant increased with increased Sm{sub 2}O{sub 3} amount at ?0.2 mol% Sm{sub 2}O{sub 3} but decreased with increased Sm{sub 2}O{sub 3} amount at >0.2 mol% Sm{sub 2}O{sub 3}.

  13. The new model of chemical evolution of r-process elements based on the hierarchical galaxy formation. I. Ba and Eu

    SciTech Connect (OSTI)

    Komiya, Yutaka; Suda, Takuma; Yamada, Shimako; Fujimoto, Masayuki Y.

    2014-03-10

    We investigate the chemical enrichment of r-process elements in the early evolutionary stages of the Milky Way halo within the framework of hierarchical galaxy formation using a semi-analytic merger tree. In this paper, we focus on heavy r-process elements, Ba and Eu, of extremely metal-poor (EMP) stars and give constraints on their astronomical sites. Our models take into account changes of the surface abundances of EMP stars by the accretion of interstellar medium (ISM). We also consider metal-enrichment of intergalactic medium by galactic winds and the resultant pre-enrichment of proto-galaxies. The trend and scatter of the observed r-process abundances are well reproduced by our hierarchical model with ∼10% of core-collapse supernovae in low-mass end (∼10 M {sub ☉}) as a dominant r-process source and the star formation efficiency of ∼10{sup –10} yr{sup –1}. For neutron star mergers as an r-process source, their coalescence timescale has to be ∼10{sup 7} yr, and the event rates ∼100 times larger than currently observed in the Galaxy. We find that the accretion of ISM is a dominant source of r-process elements for stars with [Ba/H] < –3.5. In this model, a majority of stars at [Fe/H] < –3 are formed without r-process elements, but their surfaces are polluted by the ISM accretion. The pre-enrichment affects ∼4% of proto-galaxies, and yet, is surpassed by the ISM accretion in the surface of EMP stars.

  14. Photoluminescence and cathodoluminescence properties of Eu{sup 3+} ions activated AMoO{sub 4} (A = Mg, Ca, Sr, Ba) phosphors

    SciTech Connect (OSTI)

    Du, Peng; Yu, Jae Su

    2015-10-15

    Highlights: • Under 393 nm excitation, strong red emission located at 615 nm was observed in all the samples. • The Eu{sup 3+}-activated CaMoO{sub 4} phosphor exhibited the strongest PL properties. • The CIE chromaticity coordinate of Eu{sup 3+}-activated CaMoO{sub 4} phosphor was (0.647,0.352). • The color purity of Eu{sup 3+}-activated CaMoO{sub 4} phosphor was 92.8%. • Strong CL properties were observed in the Eu{sup 3+}-activated CaMoO{sub 4} phosphor. - Abstract: Eu{sup 3+}-activated AMoO{sub 4} (A = Mg, Ca, Sr, Ba) phosphors were synthesized by a solid-state reaction method. Photoluminescence and cathodoluminescence (CL) spectra as well as X-ray diffraction patterns were measured to characterize the fabricated samples. Under 393 nm excitation, strong red emissions located at ∼615 nm corresponding to the {sup 5}D{sub 0} → {sup 7}F{sub 2} transition of Eu{sup 3+} ions were observed in all the samples. Compared with other Eu{sup 3+} ions activated AMoO{sub 4} (A = Mg, Sr, Ba) phosphors, Eu{sup 3+}-activated CaMoO{sub 4} phosphor exhibited the strongest red emission intensity with better Commission Internationale de L’Eclairage chromaticity coordinate and higher color purity. Furthermore, the CL results indicated that the Eu{sup 3+}-activated CaMoO{sub 4} phosphor had excellent luminescence properties.

  15. Ba(OH)/sub 2/. 8H/sub 2/O process for the removal and immobilization of carbon-14. Final report

    SciTech Connect (OSTI)

    Haag, G.L.; Holladay, D.W.; Pitt, W.W. Jr.; Young, G.C.

    1986-01-01

    The airborne release of /sup 14/C from various nuclear facilities has been identified as a potential biohazard due to the long half-life of /sup 14/C (5730 years) and the ease with which it may be assimilated into the biosphere. At ORNL, technology has been developed for the removal and immobilization of this radionuclide. Prior studies have indicated that /sup 14/C will likely exist in the oxidized form as CO/sub 2/ and will contribute slightly to the bulk CO/sub 2/ concentration of the gas stream, which is air-like in nature (approx.300 ppM/sub v/ CO/sub 2/). The technology that has been developed utilizes the CO/sub 2/-Ba(OH)/sub 2/.8H/sub 2/O gas-solid reaction with the mode of gas-solid contacting being a fixed bed. The product, BaCO/sub 3/, possesses excellent thermal and chemical stability, prerequisites for the long-term disposal of nuclear wastes. For optimal process operation, studies have indicated that an operating window of adequate size does exist. When operating within the window, high CO/sub 2/ removal efficiency (effluent concentrations <100 ppB/sub v/), high reactant utilization (>99%), and an acceptable pressure drop across the bed (3 kPa/m at a superficial velocity of 13 cm/s) are possible. Three areas of experimental investigation are reported: (1) microscale studies on 150-mg samples to provide information concerning surface properties, kinetics, and equilibrium vapor pressures; (2) macroscale studies on large fixed beds (4.2 kg of reactant) to determine the effects of humidity, temperature, and gas flow rate upon bed pressure drop and CO/sub 2/ breakthrough; and (3) design, construction, and operation of a pilot unit capable of continuously processing a 34-m/sup 3//h (20-ft/sup 3//min) air-based gas stream.

  16. Gallium Pnictides of the Alkaline Earth Metals, Synthesized by Means of the Flux Method: Crystal Structures and Properties of CaGa[subscript 2]Pn[subscript 2], SrGa[subscript 2]As[subscript 2], Ba[subscript 2]Ga[subscript 5]As[subscript 5], and Ba[subscript 4]Ga[subscript 5]Pn[subscript 8] (Pn = P or As)

    SciTech Connect (OSTI)

    He, Hua; Stearrett, Ryan; Nowak, Edmund R.; Bobev, Svilen

    2014-05-28

    The focus of this paper is on the structural characterization of the new Zintl phases CaGa{sub 2}P{sub 2}, CaGa{sub 2}As{sub 2}, SrGa{sub 2}As{sub 2}, and Ba{sub 2}Ga{sub 5}As{sub 5}, and the solid solution (Ba{sub 0.85(1)}Sr{sub 0.15}){sub 2}Ga{sub 5}As{sub 5}, all of which were synthesized from molten metal fluxes.CaGa{sub 2}P{sub 2}, CaGa{sub 2}As{sub 2}, and SrGa{sub 2}As{sub 2} have layered structures with polyanionic layers made of ethane-like Ga{sub 2}P6 and Ga{sub 2}As6 motifs fused through common edges; the polyanionic substructure in Ba{sub 2}Ga{sub 5}As{sub 5} consists of condensed Ga{sub 2}As6 units and GaAs{sub 4} tetrahedra. Ba{sub 4}Ga{sub 5}P{sub 8} and Ba{sub 4}Ga{sub 5}As{sub 8}, another pair of new compounds with channel-like 3D structures, were also synthesized from metal fluxes, and their structures were established from single-crystal X-ray and synchrotron powder diffraction. They are based on GaP{sub 4} and GaAs{sub 4} tetrahedra, with parts of their structures being heavily disordered. The electronic structures computed with the linear muffin-tin orbital (LMTO) method are discussed as well, alongside the thermopower and the electrical conductivity, measured on single crystals of Ba{sub 2}Ga{sub 5}As{sub 5} and the solid solution (Ba{sub 0.85(1)}Sr{sub 0.15}){sub 2} Ga{sub 5}As{sub 5}. They demonstrate that such an approach would be an effective way to fine-tune the transport properties.

  17. Final report (Grant No. DOE DE-FG02-97ER62366) [Retrieval of cloud fraction and type using broadband diffuse and total shortwave irradiance measurements

    SciTech Connect (OSTI)

    Clothiaux, Eugene

    2001-05-17

    The primary research effort supported by Grant No. DOE DEFG02-97ER62366 titled ''Retrieval of Cloud Fraction and Type Using Broadband Diffuse and Total Shortwave Irradiance Measurements'' was application of clear-sky identification and cloud fraction estimation algorithms developed by Charles N. Long and Thomas P. Ackerman to the downwelling total, direct and diffuse shortwave irradiance measurements made at all of the central, boundary, and extended facilities of the DOE Atmospheric Radiation Measurement (ARM) Program Southern Great Plains (SOP) site. Goals of the research were finalization and publication of the two algorithms in the peer-reviewed literature and operational application of them to all of aforementioned data streams from the ARM SGP site. The clear-sky identification algorithm was published as Long and Ackerman (2000) in the Journal of Geophysical Research, while a description of the cloud fraction estimation algorithm made it to the scientific literature as Long et al. (1999) in the Proceedings of the 10th American Meteorological Association Conference on Atmospheric Radiation held in Madison, Wisconsin. The cloud fraction estimation algorithm relies on empirical relationships between the outputs of the clear-sky identification algorithm and cloud fraction; as such, the cloud fraction estimation algorithm requires significant amounts of data both to properly develop the empirical relationships and to thoroughly test them. With this perspective in mind the major focus of our research efforts in the later half of the project became the operational implementation of the clear-sky identification algorithm on DOE ARM SGP data so that we could develop the data set necessary for final tuning of the cloud fraction estimation algorithm in research extending beyond the lifetime of the project.

  18. Symmetry determination on Pb-free piezoceramic 0.5Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}-0.5(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} using convergent beam electron diffraction method

    SciTech Connect (OSTI)

    Gao, Jinghui Zhong, Lisheng; Zhang, Lixue; Xue, Dezhen; Kimoto, Takayoshi; Song, Minghui; Ren, Xiaobing

    2014-02-07

    (1−x)(Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}-x(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} (BZT-xBCT) Pb-free piezoceramic has been reported showing ultrahigh piezoelectric performance in its morphotropic phase boundary (MPB) region. However, the crystal structure characteristic for the MPB composition of BZT-xBCT is still under debate—between single orthorhombic phase and tetragonal + rhombohedral two phase mixture. In the present study, we perform the local symmetry determination on the MPB composition x = 0.5 using convergent beam electron diffraction analysis (CBED). Our CBED results from multiple zone axes suggest that there are two coexisting phases with the point group symmetries of 4 mm (tetragonal) and 3 m (rhombohedral) respectively, which agree with two phase mixture model. The strong piezoelectricity can thus be understood by considering the polarization rotation between tetragonal and rhombohedral phases by external field.

  19. Phase transitions and the piezoelectricity around morphotropic phase boundary in Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}-x(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} lead-free solid solution

    SciTech Connect (OSTI)

    Zhang, Le; Zhang, Ming; Wang, Liang; Zhou, Chao; Zhang, Zhen; Yao, Yonggang; Zhang, Lixue; Xue, Dezhen E-mail: xlou03@mail.xjtu.edu.cn Lou, Xiaojie E-mail: xlou03@mail.xjtu.edu.cn; Ren, Xiaobing E-mail: xlou03@mail.xjtu.edu.cn

    2014-10-20

    In this paper, two displacive phase transitions around the morphotropic phase boundary (MPB) in Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}-x(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} (BZT-xBCT) ceramics were detected by inspecting two anomalies of the Raman Ti{sup 4+}-O{sup 2−} longitudinal optical mode (∼725 cm{sup −1}). Further, permittivity and X-ray diffraction results demonstrated these two phase transitions originate from tetragonal (T) to rhombohedral (R) through an intermediate orthorhombic (O) phase. Importantly, we found that the maximum piezoelectric response (d{sub 33} = 545pC/N) was achieved at the boundary between the T and O phase, indicating that the giant piezoelectricity of BZT-xBCT may mainly stem from the T-O phase boundary due to easier polarization rotation and larger lattice softening.

  20. miller-er-99.PDF

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

    Correction for Dry Bias in Vaisala Radiosonde RH Data E. R. Miller, J. Wang, and H. L. Cole National Center for Atmospheric Research Atmospheric Technology Division Boulder, Colorado Abstract Extensive data analysis of sounding data from the Tropical Ocean Global Atmosphere-Coupled Ocean Atmosphere Response Experiment (TOGA-COARE) and other research projects coupled with supporting evidence from other sources have lead to the conclusion that there is a dry bias in Vaisala radiosonde relative