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Sample records for ac26-07nt42677 rpsea fe

  1. Ultra-Deepwater and Unconventional Natural Gas and Other Petroleum Resources

    SciTech Connect (OSTI)

    Russell E. Fray

    2007-05-31

    RPSEA is currently in its first year of performance under contract DE-AC26-07NT42677, Ultra-Deepwater and Unconventional Natural Gas and Other Petroleum Resources Program Administration. Significant progress has been made in establishing the program administration policies, procedures, and strategic foundation for future research awards. RPSEA has concluded an industry-wide collaborative effort to identify focus areas for research awards under this program. This effort is summarized in the RPSEA Draft Annual Plan, which is currently under review by committees established by the Secretary of Energy.

  2. Ultra-Deepwater and Unconventional Natural Gas and Other Petroleum Resources

    SciTech Connect (OSTI)

    Russell E. Fray

    2007-06-30

    RPSEA is currently in its first year of performance under contract DE-AC26-07NT42677, Ultra-Deepwater and Unconventional Natural Gas and Other Petroleum Resources Program Administration. Progress continues to be made in establishing the program administration policies, procedures, and strategic foundation for future research awards. Significant progress was made in development of the draft program solicitations. In addition, RPSEA personnel continued an aggressive program of outreach to engage the industry and ensure wide industry participation in the research award solicitation process.

  3. RPSEA REPORT PROCEDURES

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMassR&D100 Winners * Impacts on Global TechnologyProceeding2-767 (REV RPSEA Final

  4. RPSEA awards a major research grant to Rubin's research group (January 2004)

    E-Print Network [OSTI]

    Rubin, Yoram

    in gas sands present in deep and ultra-deep water in the Gulf of Mexico. The project is tied to potential. The economic impact of the successful completion of the project is in the 100s of millions of dollars per year & Environmental Engineering http://www.ce.berkeley.edu/~rubin/rpsea.html 1 of 1 5/20/2014 2:45 PM #12;

  5. RPSEA REPORT PROCEDURES

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

    version 7). http:webbook.nist.govchemistry Wu, Y., Bamgbade, B. A., Baled, H., Enick, R. M., Burgess, W. A., Tapriyal, D., McHugh, M. A., "Liquid Densities of Xylene...

  6. RPSEA Final Report

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

    irrigation process for treating oil and natural gas produced waters. 2. Develop engineering and design information for implementing the pervaporation irrigation process...

  7. RPSEA Final Report

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

    the upper carbonate sequence (Arbuckle) was found to form a few streaks of dolomite-sand with variable thickness of crystalline-dolomite. The lower Precambrian sequence of...

  8. RPSEA Final Report

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMassR&D100 Winners * Impacts on Global TechnologyProceeding2-767 (REV

  9. rpsea | netl.doe.gov

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorkingLosThe 26thI D- 6 0 4 2 r m m m mrofox Ames Laboratory Profile

  10. 42677RPSEA | netl.doe.gov

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservationBio-InspiredAtmosphericdevicesPPONeApril351 Substation4.0 -ULTRA-SUPERCRITICAL

  11. RPSEA Final Report Small Producers Program Development Strategies...

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

    Texas at Austin, Bureau of Economic Geology, Workshop No. SW0020, 26 p. Anonymous, 2003, Thomas D. Barrow-a legend in wildcatting: The Leading Edge, v. 22, no. 12, p. 1218-1222....

  12. RPSEA UNCONVENTIONAL GAS CONFERENCE 2012: Geology, the Environment, Hydraulic Fracturing

    E-Print Network [OSTI]

    Yener, Aylin

    Recovery and Salt Production - Jim Silva, GE Oil & Gas 9:30 a.m. Appalachian Shale and Barnett Area Water.m. Environmentally Friendly Drilling Program Results - Rich Haut, Houston Area Research Center 11 a.m. Novel Gas

  13. Research Partnership to Secure Energy for America RPSEA | Open Energy

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page onRAPID/Geothermal/Exploration/ColoradoRemsenburg-Speonk, New York: EnergyOpen Energy Information

  14. Organometallic Complexes that Model the Active Sites of the [FeFe]- and [Fe]-Hydrogenases 

    E-Print Network [OSTI]

    Liu, Tianbiao

    2011-02-22

    of the [FeFe]-H2ase, (mu-pdt)[Fe(CO)2PMe3][Fe(CO)2NHC] (pdt = 1,3- propanedithiolate, NHC = N-heterocyclic carbene) generates mixed valent FeIIFeI models of the Hox state of [FeFe]-hydrogenase. The spectroscopic properties, structures, reactivities...

  15. Masses of Fe-61 and Fe-62 

    E-Print Network [OSTI]

    Cossairt, J. D.; Tribble, Robert E.; Kenefick, R. A.

    1977-01-01

    been measured using the Ni(a, Be) 'Fe and Ni("B,"N) Fe reactions. The mass excesses obtained are M( 'Fe) = ?58.92 ~ 0.02 MeV and M("Fe) = ?58.85 + 0.07 MeV. The results are consistent with recent predictions from two different mass relations. NUCLEAR... represents a differential cross section of about 24 pb/sr at 9?,?=10 . The mass excess is found to be -58.85+0.07 MeV. Our result is not in good agreement with the P-decay measurement that determined the mass excess to be -58.5 + 0.2 MeV (Ref. 7). We...

  16. miniFE

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservationBio-Inspired SolarAboutXu Named|Got Solitons? S andia's JuanLearnmdtestminiFE miniFE

  17. Fe(A)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HABFES OctoberEvan Racah861 ANNUAL|FacilityAboutHeatFe(A) Fe(B) O ( 0 0

  18. Measurements and calculations of metastable level lifetimes in Fe X, Fe XI, Fe XII, Fe XIII, and Fe XIV 

    E-Print Network [OSTI]

    Moehs, D. P.; Bhatti, M. I.; Church, David A.

    2001-01-01

    Lifetimes of metastable levels in the ground term of Fe ions within the 3s(2)3p(k), k=1-5, isoelectronic sequences have been measured. These measurements were performed utilizing ions that were selected by mass to charge ratio while transported from...

  19. Supporting Information for "Seasonal changes in Fe species and soluble Fe concentration in the

    E-Print Network [OSTI]

    ) ferrihydrite goethite (-FeOOH) Fe(III) oxalate Fe(III) citrate Fe(III) sulfate smectite (SWy-2) illite (IMt-1 shown. #12;2 4 6 8 10o k (A -1 ) k 3 (k) pyrite (FeS2). hematite (-Fe2O3) ferrihydrite goethite (-Fe

  20. FE Speeches and Testimony

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergy A plug-inPPLfor InnovativeProcessing22,673,list includesJune 17, 20139955/430939/FE

  1. FinalTechnicalReport_15U5O2I-11_RPSEA.docx

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

    design aspects, DNV GL has also conducted limited independent analysis on air-gap calculation and top tension riser analysis for the governing load case. DNV GL has arrived at...

  2. FinalTechnicalReport_15U5O2I-11_RPSEA.docx

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (Journal Article) |Final Report Document Number(Technical

  3. Photoionization of FE3+ Ions

    SciTech Connect (OSTI)

    Ovchinnikov, O.; Schlachter, F.

    2003-01-01

    Photoionization of Fe3+ ions was studied for the first time using synchrotron radiation from the Advanced Light Source (ALS) and the merged-beams technique. Fe3+ ions were successfully produced using ferrocene in an electron cyclotron resonance ion source (ECR). The measured yield of Fe4+ photoions as a function of photon energy revealed the presence of resonances that correspond to excitation of autoionizing states. These resonances are superimposed upon the photoion yield produced by direct photoionization, which is a smooth, slowly decreasing function of energy. The spectra for the photoionization of Fe3+ will be analyzed and compared with theory. The data collected will also serve to test models for the propagation of light through ionized matter.

  4. ORIGINAL ARTICLE [FeFe]-hydrogenase in Yellowstone National Park

    E-Print Network [OSTI]

    is an important source of energy for the maintenance and growth of microbial populations (Wolin, 1982; Morita and is the basis for many syntrophic interactions that commonly occur in microbial communities. Little is known diversity of organisms which produce H2 in microbial communities. In this study, we examined the [Fe

  5. Controlled Anisotropic Growth of Co-Fe-P from Co-Fe-O Nanoparticles

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

    Mendoza-Garcia, Adriana; Zhu, Huiyuan; Yu, Yongsheng; Li, Qing; Zhou, Lin; Su, Dong; Kramer, Matthew J.; Sun, Shouheng

    2015-06-26

    Presented here is a facile approach to bimetallic phosphides, Co-Fe-P, via high-temperature (300°C) reaction between Co-Fe-O nanoparticles and trioctylphosphine. The growth of Co-Fe-P from the Co-Fe-O is anisotropic. As a result, Co-Fe-P nanorods (from the polyhedral Co-Fe-O nanoparticles) and sea-urchin-like Co-Fe-P (from the cubic Co-Fe-O nanoparticles) are synthesized with both nanorod and the sea-urchin-arm dimensions controlled by Co/Fe ratios. The Co-Fe-P structure, especially the sea-urchin-like (Co0.54Fe0.46)2P, shows enhanced catalysis for oxygen evolution reaction in KOH with its catalytic efficiency surpassing Ir catalyst. Our synthesis is simple and may be readily extended to the preparation of other multimetallic phosphides for importantmore »catalysis and energy storage applications.« less

  6. [NiFeSe]-Hydrogenase Chemistry

    E-Print Network [OSTI]

    Wombwell, Claire; Caputo, Christine A.; Reisner, Erwin

    2015-01-01

    and selection of a suitable hydrogenase enables direct applications in electro- and photocatalysis. [FeFe]-hydrogenases display excellent H? evolution activity, but they are irreversibly damaged upon exposure to O?, which currently prevents their use in full...

  7. NNMCAB Board Minutes: November 2008 Santa Fe

    Broader source: Energy.gov [DOE]

    Minutes of the November 19, 2008 Board meeting at Santa Fe Community College Presentation LANL, Environmental Surveillance Report

  8. TESTING OF THE FE WALKING ROBOT MAY 2006 1 Testing of the FE Walking Robot

    E-Print Network [OSTI]

    Ruina, Andy L.

    TESTING OF THE FE WALKING ROBOT MAY 2006 1 Testing of the FE Walking Robot Elianna R Weyer, May and result of testing the FE walking robot during spring 2006. Improve- ments in code and launch technique. The author predicts that with continued optimization and testing, the FE walking robot can surpass

  9. Process and genes for expression and overexpression of active [FeFe] hydrogenases

    DOE Patents [OSTI]

    Seibert, Michael; King, Paul W; Ghirardi, Maria Lucia; Posewitz, Matthew C; Smolinski, Sharon L

    2014-09-16

    A process for expression of active [FeFe]-hydrogenase in a host organism that does not contain either the structural gene(s) for [FeFe]-hydrogenases and/or homologues for the maturation genes HydE, HydF and HyG, comprising: cloning the structural hydrogenase gene(s) and/or the maturation genes HydE, HydF and HydG from an organisms that contains these genes into expression plasmids; transferring the plasmids into an organism that lacks a native [FeFe]-hydrogenase or that has a disrupted [FeFe]-hydrogenase and culturing it aerobically; and inducing anaerobiosis to provide [FeFe] hydrogenase biosynthesis and H?2#191 production.

  10. Characterization of hematite (a-Fe2O3), goethite (a-FeOOH), greigite (Fe3S4), and pyrrhotite (Fe7S8) using first-order reversal

    E-Print Network [OSTI]

    Utrecht, Universiteit

    Characterization of hematite (a-Fe2O3), goethite (a-FeOOH), greigite (Fe3S4), and pyrrhotite (Fe7S8) synthetic aluminous hematite (a-Fe2-xAlxO3) and goethite (a-(FeAl)OOH) and natural greigite (Fe3S4) and pyrrhotite (Fe7S8) to constrain interpretation of FORC diagrams from natural samples. Hematite and goethite

  11. Radiation effects on interface reactions of U/Fe, U/(Fe+Cr), and U/(Fe+Cr+Ni)

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

    Shao, Lin; Chen, Di; Wei, Chaochen; Martin, Michael S.; Wang, Xuemei; Park, Youngjoo; Dein, Ed; Coffey, Kevin R.; Sohn, Yongho; Sencer, Bulent H.; et al

    2014-10-01

    We study the effects of radiation damage on interdiffusion and intermetallic phase formation at the interfaces of U/Fe, U/(Fe + Cr), and U/(Fe + Cr + Ni) diffusion couples. Magnetron sputtering is used to deposit thin films of Fe, Fe + Cr, or Fe + Cr + Ni on U substrates to form the diffusion couples. One set of samples are thermally annealed under high vacuum at 450 C or 550 C for one hour. A second set of samples are annealed identically but with concurrent 3.5 MeV Fe++ ion irradiation. The Fe++ ion penetration depth is sufficient to reachmore »the original interfaces. Rutherford backscattering spectrometry analysis with high fidelity spectral simulations is used to obtain interdiffusion profiles, which are used to examine differences in U diffusion and intermetallic phase formation at the buried interfaces. For all three diffusion systems, Fe++ ion irradiations enhance U diffusion. Furthermore, the irradiations accelerate the formation of intermetallic phases. In U/Fe couples, for example, the unirradiated samples show typical interdiffusion governed by Fick’s laws, while the irradiated ones show step-like profiles influenced by Gibbs phase rules.« less

  12. Radiation effects on interface reactions of U/Fe, U/(Fe+Cr), and U/(Fe+Cr+Ni)

    SciTech Connect (OSTI)

    Shao, Lin; Chen, Di; Wei, Chaochen; Martin, Michael S.; Wang, Xuemei; Park, Youngjoo; Dein, Ed; Coffey, Kevin R.; Sohn, Yongho; Sencer, Bulent H.; Rory Kennedy, J.

    2014-10-01

    We study the effects of radiation damage on interdiffusion and intermetallic phase formation at the interfaces of U/Fe, U/(Fe + Cr), and U/(Fe + Cr + Ni) diffusion couples. Magnetron sputtering is used to deposit thin films of Fe, Fe + Cr, or Fe + Cr + Ni on U substrates to form the diffusion couples. One set of samples are thermally annealed under high vacuum at 450 C or 550 C for one hour. A second set of samples are annealed identically but with concurrent 3.5 MeV Fe++ ion irradiation. The Fe++ ion penetration depth is sufficient to reach the original interfaces. Rutherford backscattering spectrometry analysis with high fidelity spectral simulations is used to obtain interdiffusion profiles, which are used to examine differences in U diffusion and intermetallic phase formation at the buried interfaces. For all three diffusion systems, Fe++ ion irradiations enhance U diffusion. Furthermore, the irradiations accelerate the formation of intermetallic phases. In U/Fe couples, for example, the unirradiated samples show typical interdiffusion governed by Fick’s laws, while the irradiated ones show step-like profiles influenced by Gibbs phase rules.

  13. Spatial and chemical interface asymmetry in Fe/MgO/Fe(001) heterostructures

    SciTech Connect (OSTI)

    Palomares, F.J.; Munuera, C.; Boubeta, C. Martinez; Cebollada, A. [Instituto de Ciencia de Materiales de Madrid (CSIC), Cantoblanco, 28049 Madrid (Spain); Instituto de Microelectronica de Madrid IMM (CNM-CSIC), Isaac Newton 8, P.T.M. 28760 Madrid (Spain)

    2005-02-01

    The chemical nature of the different interfaces and possible segregation effects are studied in fully epitaxial Fe/MgO/Fe (001) oriented heterostructures fabricated by combined sputtering plus laser ablation deposition techniques. Auger electron spectroscopy depth profiling experiments showed that the interfaces of the MgO spacer with the Fe layers are different, the inner MgO/Fe being spatially broader and with an FeO interlayer, while that of the outer Fe/MgO is spatially narrower with no evidence of FeO formation. This spatial and chemical asymmetry is interpreted in terms of the different deposition procedures, which affect the formation of both interfaces. No Fe segregation in the MgO layers or MgO segregation in the Fe films is observed.

  14. Interstitial Fe in MgO

    SciTech Connect (OSTI)

    Mølholt, T. E., E-mail: tem4@hi.is; Gislason, H. P.; Ólafsson, S. [Science Institute, University of Iceland, Dunhaga 3, IS-107 Reykjavík (Iceland); Mantovan, R. [Laboratorio MDM, IMM-CNR, Via Olivetti 2, 20846 Agrate Brianza (MB) (Italy); Gunnlaugsson, H. P.; Svane, A.; Weyer, G. [Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark); Masenda, H.; Naidoo, D. [School of Physics, University of the Witwatersrand, WITS 2050 (South Africa); Bharuth-Ram, K. [Durban University of Technology, Durban 4001 (South Africa); Fanciulli, M. [Laboratorio MDM, IMM-CNR, Via Olivetti 2, 20846 Agrate Brianza (MB) (Italy); Dipartimento di Scienza dei Materiali, Università di Milano Bicocca, Milano (Italy); Johnston, K. [PH Department, ISOLDE/CERN, 1211 Geneva 23 (Switzerland); Langouche, G. [Instituut voor Kern-en Stralings fysika, University of Leuven, B-3001 Leuven (Belgium); Sielemann, R. [Helmholtz-Zentrum-Berlin für Materialien und Energie, D-14109 Berlin (Germany)

    2014-01-14

    Isolated {sup 57}Fe atoms were studied in MgO single-crystals by emission Mössbauer spectroscopy following implantation of {sup 57}Mn decaying to {sup 57}Fe. Four Mössbauer spectral components were found corresponding to different Fe lattice positions and/or charge states. Two components represent Fe atoms substituting Mg as Fe{sup 2+} and Fe{sup 3+}, respectively; a third component is due to Fe in a strongly implantation-induced disturbed region. The fourth component, which is the focus of this paper, can be assigned to Fe at an interstitial site. Comparison of its measured isomer shift with ab initio calculations suggests that the interstitial Fe is located on, or close to, the face of the rock-salt MgO structure. To harmonize such an assignment with the measured near-zero quadrupole interaction a local motion process (cage motion) of the Fe has to be stipulated. The relation of such a local motion as a starting point for long range diffusion is discussed.

  15. Fe-based long range ordered alloys

    DOE Patents [OSTI]

    Liu, Chain T (Oak Ridge, TN); Inouye, Henry (Oak Ridge, TN); Schaffhauser, Anthony C. (Oak Ridge, TN)

    1980-01-01

    Malleable long range ordered alloys having high critical ordering temperatures exist in the V(Co,Fe).sub.3 and V(Co,Fe,Ni).sub.3 system having the composition comprising by weight 22-23% V, 35-50% Fe, 0-22% Co and 19-40% Ni with an electron density no greater than 8.00. Excellent high temperature properties occur in alloys having compositions comprising by weight 22-23% V, 35-45% Fe, 0-10% Co, 25-35% Ni; 22-23% V, 28-33% Ni and the remainder Fe; and 22-23% V, 19-22% Ni, 19-22% Co and the remainder Fe. The alloys are fabricable by casting, deforming and annealing for sufficient time to provide ordered structure.

  16. High-Pressure Behavior of Perovskite: FeTiO3 Dissociation into Fe1; TiO and Fe1Ti2O5

    E-Print Network [OSTI]

    Steinle-Neumann, Gerd

    High-Pressure Behavior of Perovskite: FeTiO3 Dissociation into ðFe1À; TiÞO and Fe1þTi2ÀO5 X. Wu,1 G, Australia (Received 22 January 2009; published 7 August 2009) The stability of perovskite structure, we observe in situ the breakdown of FeTiO3 perovskite into a ðFe1À; TiÞO þ Fe1þTi2ÀO5 assemblage

  17. DIELECTRONIC RECOMBINATION OF Fe xxi AND Fe xxii VIA N = 2!N0 = 2 CORE EXCITATIONS

    E-Print Network [OSTI]

    Savin, Daniel Wolf

    coefficients for the iron L-shell ions (Fe xviii­Fe xxiv). These ions are predicted to play an important role in deter- mining the thermal structure and line emission from X-ray photoionized plasmas (Hess, Kahn

  18. Fe-V redox flow batteries

    DOE Patents [OSTI]

    Li, Liyu; Kim, Soowhan; Yang, Zhenguo; Wang, Wei; Zhang, Jianlu; Chen, Baowei; Nie, Zimin; Xia, Guanguang

    2014-07-08

    A redox flow battery having a supporting solution that includes Cl.sup.- anions is characterized by an anolyte having V.sup.2+ and V.sup.3+ in the supporting solution, a catholyte having Fe.sup.2+ and Fe.sup.3+ in the supporting solution, and a membrane separating the anolyte and the catholyte. The anolyte and catholyte can have V cations and Fe cations, respectively, or the anolyte and catholyte can each contain both V and Fe cations in a mixture. Furthermore, the supporting solution can contain a mixture of SO.sub.4.sup.2- and Cl.sup.- anions.

  19. FE0023592 | netl.doe.gov

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

    FE0023592 Breakthrough Hybrid CTL Process Integrating Advanced Technologies for Coal Gasification, NG Partial Oxidation, Warm Syngas Cleanup and Syngas-to-Jet Email Page email...

  20. International science conferences in Santa Fe

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

    International science conferences International science conferences in Santa Fe The conference are 2012 International Conference on Defects in Insulating Materials and Computer...

  1. fe0024292-gti | netl.doe.gov

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

    Resources - Field Labs Hydraulic Fracturing Test Site (HFTS) Last Reviewed 1232015 DE-FE0024292 Goal This project is to conduct a field-based hydraulic fracturing research...

  2. Electrospun Polyimide Nanocomposite Fibers Reinforced with Core-Shell Fe-FeO Nanoparticles

    E-Print Network [OSTI]

    Guo, John Zhanhu

    Electrospun Polyimide Nanocomposite Fibers Reinforced with Core-Shell Fe-FeO Nanoparticles Jiahua 5, 2010; ReVised Manuscript ReceiVed: April 14, 2010 Both pure polyimide (PI) and Fe. Polyimides (PIs), a class of high-performance engineering plastics, are well-known for their excellent

  3. Quasi-elastic region of the /sup 56/Fe + /sup 56/Fe and /sup 56/Fe + /sup 238/U reactions

    SciTech Connect (OSTI)

    Weston-Dawkes, A.P.

    1986-01-01

    Projectile-like fragments (PLF's) were detected for the 15-MeV/uFe + Fe and Fe + U reactions. The mass, charge and energy of the PLF's were recorded. For the Fe + Fe reaction light-charged particles were also recorded in coincidence with PLF's. Products with kinetic energies corresponding to the first 100 MeV of energy loss were studied in detail for a variety of questions that remain concerning the quasi-elastic region. PLF energy spectra clearly show the presence of structures. These structures can be classified as either narrow or broad in kinetic energy width. By use of evaporation calculations, it was shown that broad structures were due to normal evaporation processes. Narrow structures with widths of 8 to 10 MeV could not be duplicated by evaporation calculations and their origin is still unexplained.

  4. 57Fe Mössbauer study of Lu2Fe3Si5 iron silicide superconductor

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

    Ma, Xiaoming; Ran, Sheng; Pang, Hua; Li, Fashen; Canfield, Paul C.; Bud'ko, Sergey L.

    2015-08-01

    With the advent of Fe–As based superconductivity it has become important to study how superconductivity manifests itself in details of 57Fe Mössbauer spectroscopy of conventional, Fe-bearing superconductors. The iron-based superconductor Lu2Fe3Si5 has been studied by 57Fe Mössbauer spectroscopy over the temperature range from 4.4 K to room temperature with particular attention to the region close to the superconducting transition temperature (Tc=6.1 K). Consistent with the two crystallographic sites for Fe in this structure, the observed spectra appear to have a pattern consisting of two doublets over the whole temperature range. Furthermore, the value of Debye temperature was estimated from temperaturemore »dependence of the isomer shift and the total spectral area and compared with the specific heat capacity data. Neither abnormal behavior of the hyperfine parameters at or near Tc, nor phonon softening were observed.« less

  5. NNMCAB Board Minutes: December 2014 Santa Fe

    Office of Energy Efficiency and Renewable Energy (EERE)

    Minutes of the December 10, 2014 Special Board meeting at Lodge at Santa Fe Presentation DOE HQ, Transition of Environmental Management Clean-up at LANL, Jack Craig Presentation RCLC, Perspectives from the Regional Coalition of LANL Communities, Darien Cabral

  6. Adaptive FE Methods for Conservation Equations

    E-Print Network [OSTI]

    Hartmann, Ralf

    Adaptive FE Methods for Conservation Equations Ralf Hartmann Abstract. We present an approach, University of Heidelberg. #12; 2 R. Hartmann by parts on each cell K results in X K2Th h (F (u); rv)K + (F (u

  7. FE0005961_UIllinois | netl.doe.gov

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

    RVA: 3-D Visualization and Analysis Software to Support Management of Unconventional Oil and Gas Resources Last Reviewed 1222015 DE-FE0005961 Goal This project will produce a...

  8. fe0024311-ttu | netl.doe.gov

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

    Maximize Liquid Oil Production from Shale Oil and Gas Condensate Reservoirs by Cyclic Gas Injection Last Reviewed 1242015 DE-FE0024311 Goal The project goal is to evaluate the...

  9. FINITENESS OF e Ass Fe (M) AND ITS

    E-Print Network [OSTI]

    Katzman, Moty

    FINITENESS OF e Ass Fe (M) AND ITS CONNECTIONS TO TIGHT CLOSURE. Mordechai Katzman Abstract. Let R the sets e Ass Fe(M) and e Ass Ge(M) where Fe() is the Peskine-Szpiro functor and Ge(M) is Fe(M) modulo and tight closure. The last section of this paper constructs an example which shows that e Ass Fe(M) may

  10. Sound velocities of Fe and Fe-Si alloy in the Earth's core

    E-Print Network [OSTI]

    Lin, Jung-Fu "Afu"

    , Jackson School of Geosciences, University of Texas at Austin, Austin, TX 78712; b Advanced Photon Source-ray diffraction. The nature of the Fe-Si alloy where Si is readily soluble in Fe repre- sents an ideal solid-solution), silicon (Si), sulfur (S), carbon (C), and hydrogen (H), have been suggested via cosmochemical, geo

  11. Underwater Explosive Shock Consolidation of Nanocomposite Pr2Fe14B/-Fe Magnetic Powders

    E-Print Network [OSTI]

    Liu, J. Ping

    to fabricate exchange-coupled Pr2Fe14B/-Fe nanocomposite bulk magnets, using explosively generated shock waves of Physics, University of Texas at Arlington, Arlington, Texas 76019, USA 3 Shock Wave and Condensed Matter Research Center, Kumamoto University, Kumamoto 860-8555, Japan Dynamic consolidation of powders was studied

  12. Magnetic interaction in oxygenated alpha Fe-phthalocyanines

    SciTech Connect (OSTI)

    Kuzmann, Ern?, E-mail: kuzmann@caesar.elte.hu; Homonnay, Zoltán; Horváth, Attila [Institute of Chemistry, Eötvös Loránd University, P.O. Box 32, 1512 Budapest (Hungary); Pechousek, Jiri; Cuda, Jan; Machala, Libor; Zoppellaro, Giorgio; Zboril, Radek [Regional Centre of Advanced Technologies and Materials, Departments of Experimental Physics and Physical Chemistry, Faculty of Science Palacky University, 17. Listopadu 1192/12, 771 46 Olomouc (Czech Republic); Yin, Houping; Wei, Yen [Department of Chemistry, Drexel University, Philadelphia, PA 19104 (United States); Klencsár, Zoltán [Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, 1117 (Hungary); Kubuki, Shiro [Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachi-Oji, Tokyo 192-0397 (Japan); Nath, Amar [Department of Chemistry, University of North Carolina, Asheville, NC 28804 (United States)

    2014-10-27

    Alpha iron phthalocyanines (?-FePc) oxygenated at low temperatures were investigated with the help of {sup 57}Fe Mössbauer spectroscopy, magnetization measurements (SQUID) and X-ray diffractometry (XRD). Mössbauer spectroscopy revealed that upon oxygenation of ?-FePc, new species were formed which could be associated with Fe{sup III}Pc oxygen adducts. Unexpectedly, magnetically split spectrum of oxygenated ?-FePc was observed below 20 K. In-field Mössbauer spectra in a 5 T external magnetic field at 5K and magnetization measurements indicate antiferromagnetic coupling in oxygenated ?-FePc.

  13. Membrane separation advances in FE hydrogen program

    SciTech Connect (OSTI)

    NONE

    2007-12-31

    Since its inception in Fiscal Year 2003 the US Office of Fossil Energy (FE) Hydrogen from Coal Program has sponsored more than 60 projects and made advances in the science of separating out pure hydrogen from syngas produced through coal gasification. The Program is focusing on advanced hydrogen separation technologies, which include membranes, and combining the WGS reaction and hydrogen separation in a single operation known as process intensification. The article explains the technologies and describes some key FE membrane projects. More details are available from http://www.fossil.energy.gov. 1 fig.

  14. Regulation of brain copper homeostasis by the brain barrier systems: Effects of Fe-overload and Fe-deficiency

    SciTech Connect (OSTI)

    Monnot, Andrew D.; Behl, Mamta; Ho, Sanna; Zheng, Wei

    2011-11-15

    Maintaining brain Cu homeostasis is vital for normal brain function. The role of systemic Fe deficiency (FeD) or overload (FeO) due to metabolic diseases or environmental insults in Cu homeostasis in the cerebrospinal fluid (CSF) and brain tissues remains unknown. This study was designed to investigate how blood-brain barrier (BBB) and blood-SCF barrier (BCB) regulated Cu transport and how FeO or FeD altered brain Cu homeostasis. Rats received an Fe-enriched or Fe-depleted diet for 4 weeks. FeD and FeO treatment resulted in a significant increase (+ 55%) and decrease (- 56%) in CSF Cu levels (p < 0.05), respectively; however, neither treatment had any effect on CSF Fe levels. The FeD, but not FeO, led to significant increases in Cu levels in brain parenchyma and the choroid plexus. In situ brain perfusion studies demonstrated that the rate of Cu transport into the brain parenchyma was significantly faster in FeD rats (+ 92%) and significantly slower (- 53%) in FeO rats than in controls. In vitro two chamber Transwell transepithelial transport studies using primary choroidal epithelial cells revealed a predominant efflux of Cu from the CSF to blood compartment by the BCB. Further ventriculo-cisternal perfusion studies showed that Cu clearance by the choroid plexus in FeD animals was significantly greater than control (p < 0.05). Taken together, our results demonstrate that both the BBB and BCB contribute to maintain a stable Cu homeostasis in the brain and CSF. Cu appears to enter the brain primarily via the BBB and is subsequently removed from the CSF by the BCB. FeD has a more profound effect on brain Cu levels than FeO. FeD increases Cu transport at the brain barriers and prompts Cu overload in the CNS. The BCB plays a key role in removing the excess Cu from the CSF.

  15. 90° magnetic coupling in a NiFe/FeMn/biased NiFe multilayer spin valve component investigated by polarized neutron reflectometry

    SciTech Connect (OSTI)

    Callori, S. J., E-mail: sara.callori@ansto.gov.au; Bertinshaw, J. [School of Physics, The University of New South Wales, Sydney, New South Wales 2052 (Australia); Bragg Institute, Australian Nuclear Science and Technology Organization, Lucas Heights, New South Wales 2234 (Australia); Cortie, D. L. [The Institute for Superconducting and Electronic Materials, The University of Wollongong, Wollongong, New South Wales 2522 (Australia); Bragg Institute, Australian Nuclear Science and Technology Organization, Lucas Heights, New South Wales 2234 (Australia); Cai, J. W., E-mail: jwcai@aphy.iphy.ac.cn; Zhu, T. [Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Le Brun, A. P. [Bragg Institute, Australian Nuclear Science and Technology Organization, Lucas Heights, New South Wales 2234 (Australia); Klose, F. [Bragg Institute, Australian Nuclear Science and Technology Organization, Lucas Heights, New South Wales 2234 (Australia); Department of Physics and Materials Science, City University of Hong Kong (Hong Kong)

    2014-07-21

    We have observed 90° magnetic coupling in a NiFe/FeMn/biased NiFe multilayer system using polarized neutron reflectometry. Magnetometry results show magnetic switching for both the biased and free NiFe layers, the latter of which reverses at low applied fields. As these measurements are only capable of providing information about the total magnetization within a sample, polarized neutron reflectometry was used to investigate the reversal behavior of the NiFe layers individually. Both the non-spin-flip and spin-flip neutron reflectometry signals were tracked around the free NiFe layer hysteresis loop and were used to detail the evolution of the magnetization during reversal. At low magnetic fields near the free NiFe coercive field, a large spin-flip signal was observed, indicating magnetization aligned perpendicular to both the applied field and pinned layer.

  16. Isolation and microbial reduction of Fe(III) phyllosilicates...

    Office of Scientific and Technical Information (OSTI)

    Fe(III) phyllosilicate phases, and if possible, Fe(III) oxide phases, from a weathered shale saprolite sediment in order to permit experimentation with each phase in isolation....

  17. Ferromagnetism of Fe3Sn and Alloys

    SciTech Connect (OSTI)

    Sales, Brian C [ORNL; Saparov, Bayrammurad I [ORNL; McGuire, Michael A [ORNL; Singh, David J [ORNL; Parker, David S [ORNL

    2014-01-01

    Hexagonal Fe3Sn has many of the desirable properties for a new permanent magnet phase with a Curie temperature of 725 K, a saturation moment of 1.18 MA/m. and anisotropy energy, K1 of 1.8 MJ/m3. However, contrary to earlier experimental reports, we found both experimentally and theoretically that the easy magnetic axis lies in the hexagonal plane, which is undesirable for a permanent magnet material. One possibility for changing the easy axis direction is through alloying. We used first principles calculations to investigate the effect of elemental substitutions. The calculations showed that substitution on the Sn site has the potential to switch the easy axis direction. However, transition metal substitutions with Co or Mn do not have this effect. We attempted synthesis of a number of these alloys and found results in accord with the theoretical predictions for those that were formed. However, the alloys that could be readily made all showed an in-plane easy axis. The electronic structure of Fe3Sn is reported, as are some are magnetic and structural properties for the Fe3Sn2 , and Fe5Sn3 compounds, which could be prepared as mm-sized single crystals.

  18. Magnetism in La?O?(Fe??xMnx)?Se? tuned by Fe/Mn ratio

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

    Lei, Hechang; Bozin, Emil S.; Llobet, A.; Ivanovski, V.; Koteski, V.; Belosevic-Cavor, J.; Cekic, B.; Petrovic, C.

    2012-09-01

    We report the evolution of structural and magnetic properties in La?O?(Fe??xMnx)?Se?. Heat capacity and bulk magnetization indicate an increased ferromagnetic component of the long-range magnetic order and possible increased degree of frustration. Atomic disorder on Fe(Mn) sites suppresses the temperature of the long-range order whereas intermediate alloys show a rich magnetic phase diagram.

  19. RDX degradation using an integrated Fe(0)-microbial treatment approach

    E-Print Network [OSTI]

    Alvarez, Pedro J.

    RDX degradation using an integrated Fe(0)-microbial treatment approach M.J. Wildman and P was enhanced by anaerobic bacteria that feed on cathodic hydrogen (i.e., H2 produced during anaerobic Fe(0) corrosion by water). Apparently, the hydrogenotrophic consortium that exploits Fe(0) corrosion

  20. Fe(III) Oxide Reactivity Toward Biological versus Chemical

    E-Print Network [OSTI]

    Roden, Eric E.

    size, surface area, and solubility of the mineral. Such variations lead to a continuum of Fe(III) oxideFe(III) Oxide Reactivity Toward Biological versus Chemical Reduction E R I C E . R O D E N of synthetic Fe(III) oxides with a broad range of crystallinity and specific surface area were examined

  1. Multiferroicity and spiral magnetism in FeVO{sub 4} with quenched Fe orbital moments

    SciTech Connect (OSTI)

    Daoud-Aladine, A.; Chapon, L. C.; Kundys, B.; Martin, C.; Simon, C.; Radaelli, P. G.; Brown, P. J.

    2009-12-01

    FeVO{sub 4} has been studied by heat capacity, magnetic susceptibility, electric polarization and single-crystal neutron-diffraction experiments. The triclinic crystal structure is made of S-shaped clusters of six Fe{sup 3+} ions, linked by VO{sub 4}{sup 3-} groups. Two long-range magnetic ordering transitions occur at T{sub N1}=22 K and T{sub N2}=15 K. Both magnetic structures are incommensurate and below T{sub N2}, FeVO{sub 4} becomes weakly ferroelectric coincidentally with the loss of the collinearity of the magnetic structure in a very similar fashion than in the classical TbMnO{sub 3} multiferroic material. However we argue that the symmetry considerations and the mechanisms invoked to explain these properties in TbMnO{sub 3} do not straightforwardly apply to FeVO{sub 4}. First, the magnetic structures, even the collinear structure, are all acentric so that ferroelectricity in FeVO{sub 4} is not correlated with the fact magnetic ordering is breaking inversion symmetry. Regarding the mechanism, FeVO{sub 4} has quenched orbital moments that questions the exact role of the spin-orbit interactions.

  2. Effects of Fe-enrichment on the equation of state and stability of (Mg,Fe)SiO3 perovskite

    E-Print Network [OSTI]

    Duffy, Thomas S.

    Effects of Fe-enrichment on the equation of state and stability of (Mg,Fe)SiO3 perovskite Susannah 2012 Editor: L. Stixrude Available online 8 December 2012 Keywords: perovskite post-perovskite lower and temperatures up to 3000 K. Single- phase orthorhombic GdFeO3-type perovskite was synthesized by heating

  3. Interface characterization of epitaxial Fe/MgO/Fe magnetic tunnel junctions

    SciTech Connect (OSTI)

    Wang, Shouguo; Ward, R. C. C.; Zhang, Xiaoguang; Kohn, A.; Ma, Q. L.; Zhang, J.; Liu, H. F.; Han, Prof. X. F.

    2012-01-01

    Following predictions by first-principles theory of huge tunnel magnetoresistance (TMR) effect in epitaxial Fe/MgO/Fe magnetic tunnel junctions (MTJs), measured magnetoresistance (MR) ratio about 200% at room temperature (RT) have been reported in MgO-based epitaxial MTJs. Recently, MR ratio of about 600% has been reported at RT in MgO-based amorphous MTJs with core structure of CoFeB/MgO/CoFeB grown by magnetron sputtering with amorphous CoFeB layers. The sputtered CoFeB/MgO/CoFeB MTJs shows a great potential application in spintronic devices. Although epitaxial structure will probably not be used in devices, it remains an excellent model system to compare theoretical calculations with experimental results and to enhance our understanding of the spin dependent tunneling. Both theoretical calculations and experimental results clearly indicate that the interfacial structure plays a crucial role on coherent tunneling across single crystalMgO barrier, especially in epitaxial MgO-based MTJs grown by molecular beam epitaxy (MBE). Surface X-ray diffraction, Auger electron spectroscopy, X-ray absorption spectra, and X-ray magnetic circular dichroism have been used for interface characterization. However, no consistent viewpoint has been reached, and this is still an open issue. In this article, recent studies on the interface characterization in MgO-based epitaxial MTJs will be introduced, with a focus on research by X-ray photoelectron spectroscopy, high resolution transmission electron microscopy, and spin dependent tunneling spectroscopy.

  4. Speciation of Fe in ambient aerosol and cloudwater

    SciTech Connect (OSTI)

    Siefert, L. [California Institute of Technology, Pasadena, CA (United States)

    1996-08-15

    Atmospheric iron (Fe) is thought to play an important role in cloudwater chemistry (e.g., S(IV) oxidation, oxidant production, etc.), and is also an important source of Fe to certain regions of the worlds oceans where Fe is believed to be a rate-limiting nutrient for primary productivity. This thesis focuses on understanding the chemistry, speciation and abundance of Fe in cloudwater and aerosol in the troposphere, through observations of Fe speciation in the cloudwater and aerosol samples collected over the continental United States and the Arabian Sea. Different chemical species of atmospheric Fe were measured in aerosol and cloudwater samples to help assess the role of Fe in cloudwater chemistry.

  5. In situ observation of defect annihilation in Kr ion-irradiated bulk Fe/amorphous-Fe 2 Zr nanocomposite alloy

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

    Yu, K. Y.; Fan, Z.; Chen, Y.; Song, M.; Liu, Y.; Wang, H.; Kirk, M. A.; Li, M.; Zhang, X.

    2014-08-26

    Enhanced irradiation tolerance in crystalline multilayers has received significant attention lately. However, little is known on the irradiation response of crystal/amorphous nanolayers. We report on in situ Kr ion irradiation studies of a bulk Fe96Zr4 nanocomposite alloy. Irradiation resulted in amorphization of Fe2Zr and formed crystal/amorphous nanolayers. ?-Fe layers exhibited drastically lower defect density and size than those in large ?-Fe grains. In situ video revealed that mobile dislocation loops in ?-Fe layers were confined by the crystal/amorphous interfaces and kept migrating to annihilate other defects. This study provides new insights on the design of irradiation-tolerant crystal/amorphous nanocomposites.

  6. Search for pressure-induced superconductivity in CeFeAsO and CeFePO iron pnictides

    SciTech Connect (OSTI)

    Zocco, D. A. [University of California, San Diego; Baumbach, R. E. [University of California, San Diego; Hamlin, J. J. [University of California, San Diego; Janoschek, M. [University of California, San Diego; Lum, I. K. [University of California, San Diego; McGuire, Michael A [ORNL; Safa-Sefat, Athena [ORNL; Sales, Brian C [ORNL; Jin, Rongying [ORNL; Mandrus, David [ORNL; Jeffries, J. R. [Lawrence Livermore National Laboratory (LLNL); Weir, S. T. [Lawrence Livermore National Laboratory (LLNL); Vohra, Y. K. [University of Alabama, Birmingham; Maple, M. B. [University of California, San Diego

    2011-01-01

    The CeFeAsO and CeFePO iron pnictide compounds were studied via electrical transport measurements under high pressure. In CeFeAsO polycrystals, the magnetic phases involving the Fe and Ce ions coexist for hydrostatically applied pressures up to 15 GPa, and with no signs of pressure-induced superconductivity up to 50 GPa for the less hydrostatic pressure techniques. For the CeFePO single crystals, pressure further stabilizes the Kondo screening of the Ce 4f-electron magnetic moments.

  7. VERY LATE PHOTOMETRY OF SN 2011fe

    SciTech Connect (OSTI)

    Kerzendorf, W. E. [Department of Astronomy and Astrophysics, University of Toronto, 50 Saint George Street, Toronto, ON M5S 3H4 (Canada); Taubenberger, S.; Seitenzahl, I. R.; Ruiter, A. J., E-mail: wkerzendorf@gmail.com [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Straße 1, D-85748 Garching (Germany)

    2014-12-01

    The Type Ia supernova SN 2011fe is one of the closest supernovae of the past decades. Due to its proximity and low dust extinction, this object provides a very rare opportunity to study the extremely late time evolution (>900 days) of thermonuclear supernovae. In this Letter, we present our photometric data of SN 2011fe taken at an unprecedented late epoch of ?930 days with GMOS-N mounted on the Gemini North telescope (g = 23.43 ± 0.28, r = 24.14 ± 0.14, i = 23.91 ± 0.18, and z = 23.90 ± 0.17) to study the energy production and retention in the ejecta of SN 2011fe. Together with previous measurements by other groups, our result suggests that the optical supernova light curve can still be explained by the full thermalization of the decay positrons of {sup 56}Co. This is in spite of theoretical predicted effects (e.g., infrared catastrophe, positron escape, and dust) that advocate a substantial energy redistribution and/or loss via various processes that result in a more rapid dimming at these very late epochs.

  8. Magnetic and Electronic Structure study of Fe/MgO/Fe/Co Multilayer Stack Deposited by E-Beam Evaporation

    E-Print Network [OSTI]

    Jitendra Pal Singh; Sanjeev Gautam; Braj Bhusan Singh; M. Raju; S. Chaudhary; D. Kabiraj; D. Kanjilal; Jenn-Min Lee; Jin-Ming Chen; K. Asokan; Keun Hwa Chae

    2013-05-13

    Present work investigates the magnetic and electronic structure of MgO/Fe/MgO/Fe/Co/Au multilayer stack grown on Si(100) substrates by electron beam evaporation method. X-ray diffraction study depicts polycrystalline nature of the multilayers. Results obtained from vibrating sample magnetometry (VSM) and near-edge X-ray absorption fine structure spectra (NEXAFS) at Fe & Co L- and Mg & O K-edges are applied to understand the magnetic and electronic properties of this stack and its interface properties. While the spectral features of Fe L-edge spectrum recorded by surface sensitive total electron yield (TEY) mode shows the formation of FeOx at the Fe/MgO interface, the bulk sensitive total fluorescence yield (TFY), shows Fe in metallic nature. Co L-edge spectrum reveals the presence of metallic nature of cobalt in both TEY and TFY modes. Above results are well correlated with X-ray reflectometry.

  9. Proteome of Geobacter sulfurreducens grown with Fe(III) oxide or Fe(III) citrate as the electron acceptor.

    SciTech Connect (OSTI)

    Ding, Y-H R.; Hixson, Kim K.; Aklujkar, Ma; Lipton, Mary S.; Smith, Richard D.; Lovley, Derek R.; Mester, Tunde

    2008-12-01

    e(III) oxides are the most abundant source of reducible Fe(III) by microorganisms in most soils and sediments, yet few studies on the physiology of Fe(III)-reducing microorganisms during growth on Fe(III) oxide have been conducted because of the technical difficulties in working with cell growth and harvest in the presence of Fe(III) oxides. Geobacter sulfurreducens is a representative of the Geobacter species that predominate in a variety of subsurface environments in which Fe(III) oxide is important. In order to better understand the physiology of Geobacter species during growth on Fe(III) oxide, the proteome of G. sulfurreducens grown on Fe(III) oxide was compared with the proteome of cells grown with soluble Fe(III) citrate. Two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) revealed 19 proteins that were more abundant during growth on Fe(III) oxide than on soluble Fe(III). These included proteins related to protein synthesis, electron transfer and energy production, oxidative stress, protein folding, outer membrane proteins, nitrogen metabolism and hypothetical proteins. Further analysis of the proteome with the accurate mass and time (AMT) tag method revealed additional proteins associated with growth on Fe(III) oxide. These included the outer-membrane c-type cytochrome, OmcS and OmcG, which genetic studies have suggested are required for Fe(III) oxide reduction. Furthermore, several other cytochromes, as yet unstudied, were detected to be significantly up regulated during growth on Fe(III) oxide and other proteins of unknown function were more abundant during growth on Fe(III) oxide than on soluble Fe(III). PilA, the structural protein for pili, which is required for Fe(III) oxide reduction, and other pilin-associated proteins were also more abundant during growth on Fe(III) oxide. Confirmation of the differential expression of proteins known to be important in Fe(III) oxide reduction was observed, and an additional number of previously unidentified proteins were found with significant abundance in the cells grown under conditions of Fe(III) oxide reduction.

  10. Interfacial electronic transport phenomena in single crystalline Fe-MgO-Fe thin barrier junctions

    SciTech Connect (OSTI)

    Gangineni, R. B.; Negulescu, B.; Baraduc, C.; Gaudin, G.

    2014-05-05

    Spin filtering effects in nano-pillars of Fe-MgO-Fe single crystalline magnetic tunnel junctions are explored with two different sample architectures and thin MgO barriers (thickness: 3–8 monolayers). The two architectures, with different growth and annealing conditions of the bottom electrode, allow tuning the quality of the bottom Fe/MgO interface. As a result, an interfacial resonance states (IRS) is observed or not depending on this interface quality. The IRS contribution, observed by spin polarized tunnel spectroscopy, is analyzed as a function of the MgO barrier thickness. Our experimental findings agree with theoretical predictions concerning the symmetry of the low energy (0.2?eV) interfacial resonance states: a mixture of ?{sub 1}-like and ?{sub 5}-like symmetries.

  11. Stellar and laboratory XUV/EUV line ratios in Fe XVIII and Fe XIX

    SciTech Connect (OSTI)

    Traebert, E.; Beiersdorfer, P.; Clementson, J.

    2012-05-25

    A so-called XUV excess has been suspected with the relative fluxes of Fe XVIII and Fe XIX lines observed in the XUV and EUV ranges of the spectrum of the star Capella as observed by the Chandra spacecraft, even after correction for interstellar absorption. This excess becomes apparent in the comparison of the observations with simulations of stellar spectra obtained using collisional-radiative models that employ, for example, the Atomic Plasma Emission Code (APEC) or the Flexible Atomic Code (FAC). We have addressed this problem by laboratory studies using the Livermore electron beam ion trap (EBIT).

  12. [?/Fe] ABUNDANCES OF FOUR OUTER M31 HALO STARS

    SciTech Connect (OSTI)

    Vargas, Luis C.; Geha, Marla; Tollerud, Erik J. [Department of Astronomy, Yale University, 260 Whitney Avenue, New Haven, CT 06511 (United States); Gilbert, Karoline M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Kirby, Evan N. [California Institute of Technology, 1200 East California Boulevard, MC 249-17, Pasadena, CA 91125 (United States); Guhathakurta, Puragra, E-mail: luis.vargas@yale.edu [UCO/Lick Observatory and Department of Astronomy and Astrophysics, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States)

    2014-12-10

    We present alpha element to iron abundance ratios, [?/Fe], for four stars in the outer stellar halo of the Andromeda Galaxy (M31). The stars were identified as high-likelihood field halo stars by Gilbert et al. and lie at projected distances between 70 and 140 kpc from M31's center. These are the first alpha abundances measured for a halo star in a galaxy beyond the Milky Way. The stars range in metallicity between [Fe/H] = –2.2 and [Fe/H] = –1.4. The sample's average [?/Fe] ratio is +0.20 ± 0.20. The best-fit average value is elevated above solar, which is consistent with rapid chemical enrichment from Type II supernovae. The mean [?/Fe] ratio of our M31 outer halo sample agrees (within the uncertainties) with that of Milky Way inner/outer halo stars that have a comparable range of [Fe/H].

  13. FE Petroleum Reserves News | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematics And StatisticsProgramof-SA-02:InnovativeEnergy DocketExportOil and Natural Gas News FE Oil

  14. Microsoft Word - FeV.doc

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines light on77 PAGE OF PAGESpersonal CERTIFIED MAIL August0 FOIAKansasAprilFe

  15. Microsoft Word - FeVI.doc

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines light on77 PAGE OF PAGESpersonal CERTIFIED MAIL August0 FOIAKansasAprilFe6

  16. Exponentially decaying magnetic coupling in sputtered thin film FeNi/Cu/FeCo trilayers

    SciTech Connect (OSTI)

    Wei, Yajun Akansel, Serkan; Thersleff, Thomas; Brucas, Rimantas; Lansaker, Pia; Leifer, Klaus; Svedlindh, Peter; Harward, Ian; Celinski, Zbigniew; Ranjbar, Mojtaba; Dumas, Randy K.; Jana, Somnath; Pogoryelov, Yevgen; Karis, Olof; Åkerman, Johan

    2015-01-26

    Magnetic coupling in trilayer films of FeNi/Cu/FeCo deposited on Si/SiO{sub 2} substrates have been studied. While the thicknesses of the FeNi and FeCo layers were kept constant at 100?Å, the thickness of the Cu spacer was varied from 5 to 50?Å. Both hysteresis loop and ferromagnetic resonance results indicate that all films are ferromagnetically coupled. Micromagnetic simulations well reproduce the ferromagnetic resonance mode positions measured by experiments, enabling the extraction of the coupling constants. Films with a thin Cu spacer are found to be strongly coupled, with an effective coupling constant of 3?erg/cm{sup 2} for the sample with a 5?Å Cu spacer. The strong coupling strength is qualitatively understood within the framework of a combined effect of Ruderman-Kittel-Kasuya-Yosida and pinhole coupling, which is evidenced by transmission electron microscopy analysis. The magnetic coupling constant surprisingly decreases exponentially with increasing Cu spacer thickness, without showing an oscillatory thickness dependence. This is partially connected to the substantial interfacial roughness that washes away the oscillation. The results have implications on the design of multilayers for spintronic applications.

  17. Engineering Multimetallic FePt-based nanowires for enhancing...

    Office of Scientific and Technical Information (OSTI)

    and methanol oxidation reactions Citation Details In-Document Search Title: Engineering Multimetallic FePt-based nanowires for enhancing oxygen reduction and methanol oxidation...

  18. Fe Atomic Data for Non-equilibrium Ionization Plasmas Eriksen...

    Office of Scientific and Technical Information (OSTI)

    Fe Atomic Data for Non-equilibrium Ionization Plasmas Eriksen, Kristoffer A. Los Alamos National Laboratory; Fontes, Christopher J. Los Alamos National Laboratory; Colgan,...

  19. QER Public Meeting Santa Fe, NM Electricity Infrastructure Transmissio...

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

    QER Public Meeting Santa Fe, NM Electricity Infrastructure Transmission, Storage, and Distribution - Jurisdictional issues and priorities Remarks of Susan Ackerman, Chair, Oregon...

  20. Phase coexistence in the Fe-Nd system

    SciTech Connect (OSTI)

    Cabral, F.A.O.; Gama, S. , Caixa Postal 6165, 13081 Campinas, Sao Paulo )

    1989-01-01

    The authors discuss phase coexistence in the Fe-Nd binary system investigated by metallography, x-ray diffractometry, electron microprobe analysis, and differential thermal analysis. The technique of diffusion couples also has been used. The Fe/sub 17/Nd/sub 2/ compound is peritectically formed at 1185{sup 0}C and the eutectic reaction is L {yields} Fe/sub 17/Nd/sub 2/ + Nd/sup */, occurring at 670{sup 0}C; the Fe/sub 2/Nd phase was not found. A double thermal arrest is observed at the eutectic temperature and its origin is not well understood yet.

  1. Anisotropic scattering rate in Fe-substituted Bi 2 Sr 2 Ca ( Cu 1 - x Fe x ) 2 O 8 + ?

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

    Naamneh, M.; Lubashevsky, Y.; Lahoud, E.; Gu, G. D.; Kanigel, A.

    2015-05-01

    We measured the electronic structure of Fe-substituted Bi2212 using angle-resolved photoemission spectroscopy. We find that the substitution does not change the momentum dependence of the superconducting gap but induces a very anisotropic enhancement of the scattering rate. A comparison of the effect of Fe substitution to that of Zn substitution suggests that the Fe reduces Tc so effectively because it suppresses very strongly the coherence weight around the antinodes.

  2. Chemical Reduction of U(VI) by Fe(II) at the Solid-Water Interface

    E-Print Network [OSTI]

    Roden, Eric E.

    ) oxides and highly Fe(III) oxide-enriched (18-35 wt % Fe) Atlantic coastal plain sediments. In contrast with relatively low Fe(III) oxide content (1-5 wt % Fe). Fe(II) sorption site density was severalfold lower Uranium(VI) is stable in oxic environments and typically exists as soluble carbonate complexes in aerobic

  3. Local structure of Fe in Fe-doped misfit-layered calcium cobaltite: An X-ray absorption spectroscopy study

    SciTech Connect (OSTI)

    Prasoetsopha, Natkrita; Pinitsoontorn, Supree; Bootchanont, Atipong; Kidkhunthod, Pinit; Srepusharawoot, Pornjuk; Kamwanna, Teerasak; Amornkitbamrung, Vittaya; Kurosaki, Ken; Yamanaka, Shinsuke

    2013-08-15

    Polycrystalline Ca{sub 3}Co{sub 4?x}Fe{sub x}O{sub 9+?} ceramics (x=0, 0.01, 0.03, 0.05) were fabricated using a simple thermal hydro-decomposition method and a spark plasma sintering technique. Thermoelectric property measurements showed that increasing Fe concentration resulted in a decrease in electrical resistivity, thermopower and thermal conductivity, leading to an improvement in the dimensionless figure-of-merit, >35% for x=0.05 at 1073 K. An X-ray absorption spectroscopy technique was used to investigate the local structure of Fe ions in the Ca{sub 3}Co{sub 4?x}Fe{sub x}O{sub 9+?} structure for the first time. By fitting data from the extended X-ray absorption fine structure (EXAFS) spectra and analyzing the X-ray absorption near-edge structure (XANES) spectra incorporated with first principle simulation, it was shown that Fe was substituted for Co in the the Ca{sub 2}CoO{sub 3} (rocksalt, RS) layer rather than in the CoO{sub 2} layer. Variation in the thermoelectric properties as a function of Fe concentration was attributed to charge transfer between the CoO{sub 2} and the RS layers. The origin of the preferential Fe substitution site was investigated considering the ionic radii of Co and Fe and the total energy of the system. - Graphical abstract: The Fe K-edge XANES spectra of: (a) experimental result in comparison to the simulated spectra when Fe atoms were substituted in the RS layer; (b) with magnetic moment; (c) without magnetic moment, and in the CoO{sub 2} layer; (d) with magnetic moment and (e) without magnetic moment. Highlights: • Synthesis, structural studies, and thermoelectric properties of Ca{sub 3}Co{sub 4?x}Fe{sub x}O{sub 9+?}. • Direct evidence for the local structure of the Fe ions in the Ca{sub 3}Co{sub 4?x}Fe{sub x}O{sub 9+?} using XAS analysis. • EXAFS and XANES analysis showed that Fe was likely to be situated in the RS layer structure. • Changes in TE property with Fe content was due to charge transfer between the CoO{sub 2} and the RS layers. • Total energy calculation showed energetically favorable Fe substitution in the RS layer.

  4. Structure and critical function of Fe and acid sites in Fe-ZSM-5 in propane oxidative dehydrogenation with N2O and N2O decomposition

    E-Print Network [OSTI]

    Sklenak, Stepan

    Structure and critical function of Fe and acid sites in Fe-ZSM-5 in propane oxidative species Steamed Fe-zeolites Mössbauer spectroscopy UV­Vis FTIR H2-TPR N2O decomposition Propane oxidative of propane to propene with N2O. The evacuated non-steamed FeH-ZSM-5 contained high concentration of Brønsted

  5. Is the spin transition in Fe2+ bearing perovskite

    E-Print Network [OSTI]

    Cattin, Rodolphe

    Click Here for Full Article Is the spin transition in Fe2+ bearing perovskite visible in seismology; accepted 14 June 2010; published 15 July 2010. [1] We determine the elasticity of FeSiO3 perovskite differences in seismic anisotropy between the highspin and lowspin phases of Febearing perovskite coupled

  6. MICROSTRUCTURE AND MAGNETIC PROPERTIES OF SPINODAL Fe-Cr-Co ALLOYS

    E-Print Network [OSTI]

    Okada, Masuo

    2011-01-01

    28 Isothermal wt% Co, Fe-31 wtS Cr-23 wt% Co, Cr-26 wt% Fe-system. An Fe-31 wt% Cr-23 wtS Co a l l o y was found to be

  7. Kinetics of Fe(II)-catalyzed transformation of 6-line ferrihydrite under anaerobic flow conditions

    E-Print Network [OSTI]

    Yang, L.

    2010-01-01

    transformation to goethite via the Fe(II) pathway. Am.ferrihydrite, and goethite. Geochim. Cosmochim. Acta 2001,between Aqueous Fe(II) and Goethite: An Fe Isotope Tracer

  8. Influence of alloying elements on grain-growth in Zr(Fe) and Cu(Fe) thin-films under in situ ion-irradiation

    E-Print Network [OSTI]

    Motta, Arthur T.

    Influence of alloying elements on grain-growth in Zr(Fe) and Cu(Fe) thin-films under in situ ion-irradiation(Fe) and Cu(Fe) were ion-irradiated in situ in a transmission electron microscope to study the influence of mixing and Cu­Fe a positive heat of mixing. Irradiations conducted at temperatures of 20­573 K showed

  9. Multiple-Timescale Photoreactivity of a Model Compound Related to the Active Site of [FeFe]-Hydrogenase

    E-Print Network [OSTI]

    Strathclyde, University of

    of iron carbonyl sulfide, Fe2(CO)6(µ- S2), in a Nujol matrix show that the two lowest-energy transitions carbonyl ligand photolysis. The Fe-only hydrogenases reversibly catalyze the reduction of protons, as well as the loss of the infrared (IR) band associated with the bridging carbonyl ligand.6 Pho- tolysis

  10. Controlling the crystallization and magnetic properties of melt-spun Pr2Fe14B -Fe nanocomposites by Joule heating

    E-Print Network [OSTI]

    Liu, J. Ping

    the crystallization behavior during Joule heating and to identify the heat-treatment conditions for optimum magnetic- ation is to increase heating rate in attempts to avoid the for- mation of undesired phases duringControlling the crystallization and magnetic properties of melt-spun Pr2Fe14BÕ -Fe nanocomposites

  11. Pressure-induced amorphization of CuFeS2 studied by 57 Fe nuclear resonant inelastic scattering

    E-Print Network [OSTI]

    Alfè, Dario

    Hisao Kobayashi,* Junpei Umemura, Yutaka Kazekami, and Nobuhiko Sakai Graduate School of Material structural properties of CuFeS2 under high pressure were investigated by x-ray diffrac- tion and 57 Fe centered tetragonal lattice with space group I4¯2d, which is an antiferromagnetic semiconductor with high

  12. Controlling the crystallization and magnetic properties of melt-spun Pr2Fe14B -Fe nanocomposites by Joule heating

    E-Print Network [OSTI]

    Wang, Zhong L.

    Controlling the crystallization and magnetic properties of melt-spun Pr2Fe14BÕ -Fe nanocomposites by Joule heating Z. Q. Jin School of Materials Science and Engineering, Georgia Institute of Technology by means of ac Joule heating while simultaneously monitoring room-temperature electrical resistance R

  13. Stability of precipitate phases in Fe-rich Fe-Cr-Ni-Mo alloys

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

    Yang, Ying; Tan, Lizhen; Busby, Jeremy T

    2015-01-01

    Understanding the stability of precipitate phases in the Fe-rich Fe-Cr-Ni-Mo alloys is critical to the alloy design and application of Mo-containing Austenitic steels. Coupled with thermodynamic modeling, stability of the and phases in two Fe-Cr-Ni-Mo alloys were investigated at 1000, 850 and 700 C for different annealing time. The morphologies, compositions and crystal structures of the matrix and precipitate phases were carefully examined by Scanning Electron Microscopy, Electron Probe Microanalysis, X-ray diffraction and Transmission Electron Microscopy. Two key findings resulted from this work. One is that the phase is stable at high temperature and transformed into the phase at lowmore »temperature. The other is that both the and phases have large solubilites of Cr, Mo and Ni, among which the Mo solubility has a major role on the relative stability of the precipitate phases. The developed thermodynamic models were then applied to evaluating the Mo effect on the stability of precipitate phases in AISI 316 and NF709 alloys.« less

  14. Thermal stability of intermetallic phases in Fe-rich Fe-Cr-Ni-Mo alloys

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

    Yang, Ying; Tan, Lizhen; Busby, Jeremy T.

    2015-06-12

    Understanding the stability of precipitate phases in the Fe-rich Fe-Cr-Ni-Mo alloys is critical to the alloy design and application of Mo-containing Austenitic steels. Coupled with thermodynamic modeling, stability of the chi and Laves phases in two Fe-Cr-Ni-Mo alloys were investigated at 1000, 850 and 700 °C for different annealing time. The morphologies, compositions and crystal structures of the matrix and precipitate phases were carefully examined by Scanning Electron Microscopy, Electron Probe Microanalysis, X-ray diffraction and Transmission Electron Microscopy. The two key findings resulted from this work. One is that the chi phase is stable at high temperature and transformed intomore »the Laves phase at low temperature. The other is that both the chi and Laves phases have large solubilites of Cr, Mo and Ni, among which the Mo solubility has a major role on the relative stability of the precipitate phases. The developed thermodynamic models were then applied to evaluating the Mo effect on the stability of precipitate phases in AISI 316 and NF709 alloys.« less

  15. High precision density measurements in the solar corona: I. Analysis methods and results for Fe XII and Fe XIII

    E-Print Network [OSTI]

    P. R. Young; T. Watanabe; H. Hara; J. T. Mariska

    2008-10-28

    The EUV Imaging Spectrometer (EIS) instrument on board the Hinode satellite has access to some of the best coronal density diagnostics and the high sensitivity of the instrument now allows electron number density, N_e, measurements to an unprecedented precision of up to +/-5 % in active regions. This paper gives a thorough overview of data analysis issues for the best diagnostics of Fe XII and Fe XIII and assesses the accuracy of the measurements. Two density diagnostics each from Fe XII (186.88/195.12 and 196.64/195.12) and Fe XIII (196.54/202.04 and 203.82/202.04) are analysed in two active region data-sets from 2007 May 3 and 6 that yield densities in the range 8.5 < log N_e < 11.0. The densities are derived using v5.2 of the CHIANTI atomic database. The Fe XII and Fe XIII diagnostics show broadly the same trend in density across the active region, consistent with their similar temperatures of formation. However the high precision of the EIS measurements demonstrates significant discrepancies of up to 0.5 dex in derived log N_e values, with Fe XII always giving higher densities than Fe XIII. The discrepancies may partly be due to real physical differences between the emitting regions of the two plasmas, but the dominant factor lies in the atomic models of the two ions. Two specific problems are identified for Fe XII 196.64 and Fe XIII 203.82: the former is found to be under-estimated in strength by the CHIANTI atomic model, while the high density limit of the 203.82/202.04 is suggested to be inaccurate in the CHIANTI atomic model. The small grating tilt of the EIS instrument is found to be very significant when deriving densities from emission lines separated by more than a few angstroms.

  16. Accelerated decarburization of Fe-C metal alloys

    DOE Patents [OSTI]

    Pal, U.B.; Sadoway, D.R.

    1997-05-27

    A process is described for improving the rate of metal production and FeO utilization in a steelmaking process or a process combining iron-making and steelmaking in a single reactor that uses or generates Fe-C metal alloy droplets submerged in an FeO-containing slag. The process involves discharging a charge build-up (electron accumulation) in the slag at the slag-metal alloy interface by means of an electron conductor connected between the metal alloy droplets and a gas at a gas-slag interface, said gas having an oxygen partial pressure of at least about 0.01 atmosphere. 2 figs.

  17. Constructing Hierarchical Interfaces: TiO2-Supported PtFe-FeOx Nanowires for Room Temperature CO Oxidation

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

    Zhu, Huiyuan; Wu, Zili; Dong, Su; Veith, Gabriel M; Lu, Hanfeng; Zhang, Pengfei; Chai, Songhai; Dai, Sheng

    2015-08-05

    This is a report of a facile approach to constructing catalytic active hierarchical interfaces in one-dimensional (1D) nanostructure, exemplified by the synthesis of TiO2-supported PtFe–FeOx nanowires (NWs). The hierarchical interface, constituting atomic level interactions between PtFe and FeOx within each NW and the interactions between NWs and support (TiO2), enables CO oxidation with 100% conversion at room temperature. We identify the role of the two interfaces by probing the CO oxidation reaction with isotopic labeling experiments. Both the oxygen atoms (Os) in FeOx and TiO2 participate in the initial CO oxidation, facilitating the reaction through a redox pathway. Moreover, themore »intact 1D structure leads to the high stability of the catalyst. After 30 h in the reaction stream, the PtFe–FeOx/TiO2 catalyst exhibits no activity decay. These results provide a general approach and new insights into the construction of hierarchical interfaces for advanced catalysis.« less

  18. Synthesis and properties of titanomagnetite (Fe3-xTixO4) nanoparticles: A tunable solid-state Fe(II/III) redox system

    SciTech Connect (OSTI)

    Pearce, Carolyn I.; Qafoku, Odeta; Liu, Juan; Arenholz, Elke; Heald, Steve M.; Kukkadapu, Ravi K.; Gorski, Christopher A.; Henderson, C. Michael B.; Rosso, Kevin M.

    2012-12-01

    Titanomagnetite (Fe3-xTixO4) nanoparticles were synthesized by room temperature aqueous precipitation, in which Ti(IV) replaces Fe(III) and is charge compensated by conversion of Fe(III) to Fe(II) in the unit cell. A comprehensive suite of tools was used to probe composition, structure, and magnetic properties down to site-occupancy level, emphasizing distribution and accessibility of Fe(II) as a function of x. Synthesis of nanoparticles in the range 0 ? x ? 0.6 was attempted; Ti, total Fe and Fe(II) content were verified by chemical analysis. TEM indicated homogeneous spherical 10 12 nm particles. ?-XRD and Mössbauer spectroscopy on anoxic aqueous suspensions verified the inverse spinel structure and Ti(IV) incorporation in the unit cell up to x ? 0.38, based on Fe(II)/Fe(III) ratio deduced from the unit cell edge and Mössbauer spectra. Nanoparticles with a higher value of x possessed a minor amorphous secondary Fe(II)/Ti(IV) phase. XANES/EXAFS indicated Ti(IV) incorporation in the octahedral sublattice (B-site) and proportional increases in Fe(II)/Fe(III) ratio. XA/XMCD indicate these increases arise from increasing B-site Fe(II), and that these charge-balancing equivalents segregate to those B-sites near particle surfaces. Dissolution studies showed that this segregation persists after release of Fe(II) into solution, in amounts systematically proportional to x and thus the Fe(II)/Fe(III) ratio. A mechanistic reaction model was developed entailing mobile B-site Fe(II) supplying a highly interactive surface phase that undergoes interfacial electron transfer with oxidants in solution, sustained by outward Fe(II) migration from particle interiors and concurrent inward migration of charge-balancing cationic vacancies in a ratio of 3:1.

  19. Clean Energy- FE Dkt No. 14-54-LNG (FTA)

    Broader source: Energy.gov [DOE]

    The Office of Fossil Energy (FE) of the Department of Energy (DOE) gives notice of receipt of an application filed on March 18, 2014, by Clean Energy, requesting blanket authorization to engage in...

  20. FE Leaders Discuss African Energy Development | Department of...

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

    FE's Christopher Smith spoke recently during the Africa Leaders Visit: Energy event in Houston. During the three-day event organized by the U.S. Trade Development Agency,...

  1. Electrochemical Model of the Fe/V Redox Flow Battery

    SciTech Connect (OSTI)

    Stephenson, David E.; Kim, Soowhan; Chen, Feng; Thomsen, Edwin C.; Viswanathan, Vilayanur V.; Wang, Wei; Sprenkle, Vincent L.

    2012-11-05

    This paper presents a mathematical model for the new Fe/V redox flow battery chemistry. The model is designed to be useful for stack development and cost analysis purposes.

  2. Hydrogen-Vacancy Interactions in Fe-C Alloys

    E-Print Network [OSTI]

    Yip, Sidney

    Energetics and concentrations of hydrogen-containing point defect clusters (PDCs) in Fe-C alloys are calculated and cast into a PDC dominance diagram. Because of the strong binding effects of iron vacancies on the stability ...

  3. Magneto-optical characterizations of FeTe???Se??? thin...

    Office of Scientific and Technical Information (OSTI)

    in the two thin films. Compared with bulk crystals, FeTeSe thin film demonstrates not only higher Tc, but also much larger Jc, which is attractive for...

  4. Duo at Santa Fe's Monte del Sol Charter

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

    New Mexico Supercomputing Challenge April 21, 2015 Using nanotechnology robots to kill cancer cells LOS ALAMOS, N.M., April 21, 2015-Meghan Hill and Katelynn James of Santa Fe's...

  5. Iron Corrosion Observations: Pu(VI)-Fe Reduction Studies

    SciTech Connect (OSTI)

    Reed, Donald T. [Los Alamos National Laboratory; Swanson, Juliet S. [Los Alamos National Laboratory; Richmann, Michael K. [Los Alamos National Laboratory; Lucchini, Jean-Francois [Los Alamos National Laboratory; Borkowski, Marian [Los Alamos National Laboratory

    2012-09-11

    Iron and Pu Reduction: (1) Very different appearances in iron reaction products were noted depending on pH, brine and initial iron phase; (2) Plutonium was associated with the Fe phases; (3) Green rust was often noted at the higher pH; (4) XANES established the green rust to be an Fe2/3 phase with a bromide center; and (5) This green rust phase was linked to Pu as Pu(IV).

  6. Demonstration of Security Benefits of Renewable Generation at FE Warren Air Force Base

    SciTech Connect (OSTI)

    Warwick, William M.; Myers, Kurt; Seifert, Gary

    2010-12-31

    Report detailing field demonstration of security benefits of renewable generation at FE Warren Air Force Base.

  7. Mössbauer investigations of hyperfine interactions features of {sup 57}Fe nuclei in BiFeO{sub 3} ferrite

    SciTech Connect (OSTI)

    Sobolev, Alexey, E-mail: salex12@rambler.ru; Presniakov, Igor, E-mail: salex12@rambler.ru; Rusakov, Vyacheslav, E-mail: salex12@rambler.ru; Matsnev, Mikhail; Gorchakov, Dmitry; Glazkova, Iana [Lomonosov Moscow State University, 119991, Moscow (Russian Federation); Belik, Alexey [International Center for Materials Nanoarchitectonics (MANA), National Institute for Material Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki, 305-0044 (Japan)

    2014-10-27

    New results of {sup 57}Fe Mössbauer studies on BiFeO{sub 3} powder sample performed at various temperatures above and below magnetic phase transitions point T{sub N} ? 640K are reported. We have performed self-consistent calculations of the lattice contributions to the EFG tensor, taking into account dipole moments of the O{sup 2?} and Bi{sup 3+} ions. Low-temperature {sup 57}Fe Mössbauer spectra recorded at T < T{sub N} were analyzed assuming an anharmonic cycloidal modulation of the Fe{sup 3+} magnetic moments. The cycloidal modulation of the iron spin was described with the elliptic Jacobi function sn[(±4K(m)/?)x,m]. The good fit of the experimental spectra was obtained for the anharmonicity m = 0.44 ± 0.04 (T = 4.9K) resulting from the easy-axis magnetic anisotropy.

  8. Fe3+/Fe2+ mycobactin-complex electrochemistry as an approach to determine mycobactin levels in urine.

    E-Print Network [OSTI]

    McBride, Nicholas; Hall, Elizabeth A. H.

    2015-03-05

    Mycobacterium acquire iron by producing siderophores called mycobactins, with an extremely high affinity complexation of Fe3+. The iron complex shows distinctive electrochemistry predicting 18 orders of magnitude greater affinity of the mycobactin...

  9. Role of structural Fe in nontronite NAu-1 and dissolved Fe(II) in redox transformations of arsenic and antimony

    SciTech Connect (OSTI)

    Ilgen, Anastasia G.; Foster, Andrea L.; Trainor, Thomas P. (Alaska Fairbanks); (USGS)

    2012-11-01

    Oxidation state is a major factor affecting the mobility of arsenic (As) and antimony (Sb) in soil and aquatic systems. Metal (hydr)oxides and clay minerals are effective sorbents, and may also promote redox reactions on their surfaces via direct or indirect facilitation of electron transfer. Iron substituted for Al in the octahedral sites of aluminosilicate clay minerals has the potential to be in variable oxidation states and is a key constituent of electron transfer reactions in clay minerals. This experimental work was conducted to determine whether structural Fe in clays can affect the oxidation state of As and Sb adsorbed at the clay surface. Another goal of our study was to compare the reactivity of clay structural Fe(II) with systems containing Fe(II) present in dissolved/adsorbed forms. The experimental systems included batch reactors with various concentrations of As(III), Sb(III), As(V), or Sb(V) equilibrated with oxidized (NAu-1) or partially reduced (NAu-1-Red) nontronite, hydrous aluminum oxide (HAO) and kaolinite (KGa-1b) suspensions under oxic and anoxic conditions. The reaction times ranged from 0.5 to 720 h, and pH was constrained at 5.5 (for As) and at 5.5 or 8.0 (for Sb). The oxidation state of As and Sb in the liquid phase was determined by liquid chromatography in line with an inductively coupled plasma mass spectrometer, and in the solid phase by X-ray absorption spectroscopy. Our findings show that structural Fe(II) in NAu-1-Red was not able to reduce As(V)/Sb(V) under the conditions examined, but reduction was seen when aqueous Fe(II) was present in the systems with kaolinite (KGa-1b) and nontronite (NAu-1). The ability of the structural Fe in nontronite clay NAu-1 to promote oxidation of As(III)/Sb(III) was greatly affected by its oxidation state: if all structural Fe was in the oxidized Fe(III) form, no oxidation was observed; however, when the clay was partially reduced ({approx}20% of structural Fe was reduced to Fe(II)), NAu-1-Red promoted the most extensive oxidation under both oxic and anoxic conditions. Electron balance considerations suggest that structural Fe(III) in the NAu-1-Red was the sole oxidant in the anoxic setup, while dissolved O{sub 2} also contributes in oxic conditions. Long-term batch experiments revealed the complex dynamics of As aqueous speciation in anoxic and oxic systems when reduced arsenic was initially added: rapid disappearance of As(III) was observed due to oxidation to As(V) followed by a slow increase of aqueous As(III). This behavior is explained by two reactions: fast initial oxidation of As(III) by structural Fe(III) (anoxic) or Fe(III) and dissolved O2 (oxic) followed by the slow reduction of As(V) by dissolved Fe(II). The resulting re-mobilization of As due to As(V) reduction by aqueous Fe(II) occurs on time scales on the order of days. These reactions are likely significant in a natural soil or aquifer environment with seasonal cycling or slightly reducing conditions with an abundance of clay minerals and dissolved Fe(II).

  10. Campbell penetration depth in Fe-based superconductors

    SciTech Connect (OSTI)

    Prommapan, Plegchart

    2011-08-15

    A 'true' critical current density, j{sub c}, as opposite to commonly measured relaxed persistent (Bean) current, j{sub B}, was extracted from the Campbell penetration depth, {lambda}{sub c}(T,H) measured in single crystals of LiFeAs, and optimally electron-doped Ba(Fe{sub 0.954}Ni{sub 0.046}){sub 2}As{sub 2} (FeNi122). In LiFeAs, the effective pinning potential is nonparabolic, which follows from the magnetic field - dependent Labusch parameter {alpha}. At the equilibrium (upon field - cooling), {alpha}(H) is non-monotonic, but it is monotonic at a finite gradient of the vortex density. This behavior leads to a faster magnetic relaxation at the lower fields and provides a natural dynamic explanation for the fishtail (second peak) effect. We also find the evidence for strong pinning at the lower fields.The inferred field dependence of the pinning potential is consistent with the evolution from strong pinning, through collective pinning, and eventually to a disordered vortex lattice. The value of j{sub c}(2 K) {approx_equal} 1.22 x 10{sup 6} A/cm{sup 2} provide an upper estimate of the current carrying capability of LiFeAs. Overall, vortex behavior of almost isotropic, fully-gapped LiFeAs is very similar to highly anisotropic d-wave cuprate superconductors, the similarity that requires further studies in order to understand unconventional superconductivity in cuprates and pnictides. In addition to LiFeAs, we also report the magnetic penetration depth in BaFe{sub 2}As{sub 2} based superconductors including irradiation of FeNi122. In unirradiated FeNi122, the maximum critical current value is, j{sub c}(2K) {approx_equal} 3.3 x 10{sup 6} A/cm{sup 2}. The magnetic-dependent feature was observed near the transition temperature in FeTe{sub 0.53}Se{sub 0.47} and irradiated FeNi122. Because of this feature, further studies are required in order to properly calibrate the Campbell penetration depth. Finally, we detected the crossing between the magnetic penetration depth and London penetration depth in optimally hold-doped Ba{sub 0.6}K{sub 0.4}Fe{sub 2}As{sub 2} (BaK122) and isovalent doped BaFe{sub 2}(As{sub 0.7}P{sub 0.3}){sub 2} (BaP122). These phenomena probably coincide with anomalous Meissner effect reported in pnicitde superconductors [Prozorov et al. (2010b)] however more studies are needed in order to clarify this.

  11. N2s2 chelating agents as cys-x-cys biomimics for fe(no) and fe(no)2 complexes 

    E-Print Network [OSTI]

    Chiang, Chao-Yi

    2006-08-16

    model complexes I have examined the fundamental properties of a dithiolato-Fe(NO)2 complex, bismercaptoethandiazacyclooctane iron dinitrosyl or (H+bme-daco)Fe(NO)2 as a biomimic of dicysteinate coordination of [Fe(NO)2]. This complex was prepared...

  12. Effect of Ag addition to L1{sub 0} FePt and L1{sub 0} FePd films grown by molecular beam epitaxy

    SciTech Connect (OSTI)

    Tokuoka, Y.; Seto, Y.; Kato, T.; Iwata, S.

    2014-05-07

    L1{sub 0} ordered FePt-Ag (5?nm) and FePd-Ag (5?nm) films were grown on MgO (001) substrate at temperatures of 250–400?°C by using molecular beam epitaxy method, and their crystal and surface structures, perpendicular magnetic anisotropies and Curie temperatures were investigated. In the case of FePt-Ag, Ag addition with the amount of 10–20 at.?% was effective to promote L1{sub 0} ordering and granular growth, resulting in the increase of the perpendicular magnetic anisotropy and coercivity of the FePt-Ag films. On the other hand, in the case of FePd-Ag, Ag addition changed the surface morphology from island to continuous film associated with the reductions of its coercivity and perpendicular anisotropy. The variations of lattice constants and Curie temperature with Ag addition were significantly different between FePt-Ag and FePd-Ag. For FePd-Ag, the c and a axes lattice spacings and Curie temperature gradually changed with increasing Ag content, while they unchanged for FePt-Ag. These results suggest the possibility of the formation of FePdAg alloy in FePd-Ag, while Ag segregation in FePt-Ag.

  13. Dual and Triple Ion-Beam Irradiations of Fe, Fe(Cr) and Fe(Cr)-ODS Final Report: IAEA SMoRE CRP

    SciTech Connect (OSTI)

    Fluss, M J; Hsiung, L L; Marian, J

    2011-11-20

    Structures of nanoparticles in Fe-16Cr-4.5Al-0.3Ti-2W-0.37Y2O3 (K3) and Fe-20Cr-4.5Al-0.34Ti-0.5Y2O3 (MA956) oxide dispersion strengthened (ODS) ferritic steels produced by mechanical alloying (MA) and followed by hot extrusion have been studied using high-resolution transmission electron microscopy (HRTEM) techniques to gain insight about the formation mechanism of nanoparticles in MA/ODS steels. The observations of Y-Al-O complex-oxide nanoparticles in both ODS steels imply that decomposition of Y2O3 in association with internal oxidation of Al occurred during mechanical alloying. While the majority of oxide nanoparticles formed in both steels is Y4Al2O9, a few oxide particles of YAlO3 are also occasionally observed. These results reveal that Ti (0.3 wt %) plays an insignificant role in forming oxide nanoparticles in the presence of Al (4.5 wt %). HRTEM observations of crystalline nanoparticles larger than {approx}2 nm and amorphous or disordered cluster domains smaller than {approx}2 nm provide an insight into the formation mechanism of oxide nanoparticle in MA/ODS steels, which we believe from our observations involves a solid-state amorphous precursor followed by recrystallization. Dual ion-beam irradiations using He{sup +} + Fe{sup +8} ions were employed to gain more detailed insight about the role of nanoparticles in suppressing radiation-induced swelling. This is elaborated through TEM examinations of cavity distributions in ion-irradiated Fe-14Cr and K3-ODS ferritic steels. HRTEM observations of helium-filled cavities (helium bubbles) preferably trapped at nanoscale oxide particles and clusters in ion-irradiated K3-ODS are presented. Finally, we describe the results from triple ion-beam irradiations using H{sup +} + He{sup +} + Fe{sup +8} ions to emulate fusion first wall radiation effects. Preliminary work is reported that confirms the existence of significant hydrogen synergistic effects described earlier by Tanaka et al., for Fe(Cr) and by Wakai et al., for F82H reduced activation ferritic martensitic (RAF/M) steel. These previous results combined with our data suggest a complex new 'catalytic' mechanism whereby H interacts with the steady state population of defects and the embryonic cavities so as to accelerated cavity (void) growth in both Fe(Cr) and under special conditions in ODS steels.

  14. Microporous Separators for Fe/V Redox Flow Batteries

    SciTech Connect (OSTI)

    Wei, Xiaoliang; Li, Liyu; Luo, Qingtao; Nie, Zimin; Wang, Wei; Li, Bin; Xia, Guanguang; Miller, Eric; Chambers, Jeff; Yang, Zhenguo

    2012-06-28

    The Fe/V redox flow battery has demonstrated promising performance that is advantageous over other redox flow battery systems. The less oxidative nature of the Fe(III) species enables use of hydrocarbon - based ion exchange membranes or separators. Daramic(reg. sign) microporous polyethylene separators were tested on Fe/V flow cells using the sulphuric/chloric mixed acid - supporting electrolytes. Among them, Daramic(reg. sign) C exhibited good flow cell cycling performance with satisfactory repeatability over a broad temperature range of 5 - 50 degrees C. Energy efficiency (EE) of C remains above 67% at current densities of 50 - 80 cm{sup -2} in the temperature range from room temperature to 50 degrees C. The capacity decay problem could be circumvented through hydraulic pressure balancing by applying different pump rates to the positive and negative electrolytes. Stable capacity and energy were obtained over 40 cycles at room temperature and 40 degrees C. These results manifest that the extremely low-cost separators ($10/cm2) are applicable in the Fe/V flow battery system at an acceptable sacrifice of energy efficiency. This stands for a remarkable breakthrough in significant reduction of the capital cost of the Fe/V flow battery system, and is promising to promote its market penetration in grid stabilization and renewable integration.

  15. Single-crystal epitaxial thin films of SrFeO{sub 2} with FeO{sub 2} 'infinite layers'

    SciTech Connect (OSTI)

    Inoue, Satoru; Kawai, Masanori; Shimakawa, Yuichi [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan); Mizumaki, Masaichiro; Kawamura, Naomi [Japan Synchrotron Radiation Research Institute/SPring-8, Sayo, Hyogo 679-5198 (Japan); Watanabe, Takashi; Tsujimoto, Yoshihiro; Kageyama, Hiroshi; Yoshimura, Kazuyoshi [Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502 (Japan)

    2008-04-21

    Single-crystal thin films of SrFeO{sub 2}, which is an oxygen-deficient perovskite with ''infinite layers'' of Fe{sup 2+}O{sub 2}, were prepared by using CaH{sub 2} for low-temperature reduction of epitaxial SrFeO{sub 2.5} single-crystal films deposited on KTaO{sub 3} substrates. This reduction process, removing oxygen ions from the perovskite structure framework and causing rearrangements of oxygen ions, topotactically transforms the brownmillerite SrFeO{sub 2.5} to the c-axis oriented SrFeO{sub 2}.

  16. Bimetallic Fe-Ni Oxygen Carriers for Chemical Looping Combustion

    SciTech Connect (OSTI)

    Bhavsar, Saurabh; Veser, Goetz

    2013-11-06

    The relative abundance, low cost, and low toxicity of iron make Fe-based oxygen carriers of great interest for chemical looping combustion (CLC), an emerging technology for clean and efficient combustion of fossil and renewable fuels. However, Fe also shows much lower reactivity than other metals (such as Ni and Cu). Here, we demonstrate strong improvement of Fe-based carriers by alloying the metal phase with Ni. Through a combination of carrier synthesis and characterization with thermogravimetric and fixed-bed reactor studies, we demonstrate that the addition of Ni results in a significant enhancement in activity as well as an increase in selectivity for total oxidation. Furthermore, comparing alumina and ceria as support materials highlights the fact that reducible supports can result in a strong increase in oxygen carrier utilization.

  17. Spin-Lattice Coupling and Superconductivity in Fe Pnictides

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

    Egami, T.; Fine, B. V.; Parshall, D.; Subedi, A.; Singh, D. J.

    2010-01-01

    We consider strong spin-lattice and spin-phonon coupling in iron pnictides and discuss its implications on superconductivity. Strong magneto-volume effect in iron compounds has long been known as the Invar effect. Fe pnictides also exhibit this effect, reflected in particular on the dependence of the magnetic moment on the atomic volume of Fe defined by the positions of the nearest neighbor atoms. Through the phenomenological Landau theory, developed on the basis of the calculations by the density functional theory (DFT) and the experimental results, we quantify the strength of the spin-lattice interaction as it relates to the Stoner criterion for themore »onset of magnetism. We suggest that the coupling between electrons and phonons through the spin channel may be sufficiently strong to be an important part of the superconductivity mechanism in Fe pnictides.« less

  18. Structural and Electrochemical Characterization of PureLiFePO4and Nanocomposite C-LiFePO4Cathodes for Lithium Ion Rechargeable Batteries

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

    Kumar, Arun; Thomas, R.; Karan, N. K.; Saavedra-Arias, J. J.; Singh, M. K.; Majumder, S. B.; Tomar, M. S.; Katiyar, R. S.

    2009-01-01

    Pure lithium iron phosphate (LiFePO4) and carbon-coatedLiFePO4(C-LiFePO4) cathode materials were synthesized for Li-ion batteries. Structural and electrochemical properties of these materials were compared. X-ray diffraction revealed orthorhombic olivine structure. Micro-Raman scattering analysis indicates amorphous carbon, and TEM micrographs show carbon coating onLiFePO4particles. Ex situ Raman spectrum of C-LiFePO4at various stages of charging and discharging showed reversibility upon electrochemical cycling. The cyclic voltammograms ofLiFePO4and C-LiFePO4showed only a pair of peaks corresponding to the anodic and cathodic reactions. The first discharge capacities were 63, 43, and 13?mAh/g for C/5, C/3, and C/2, respectively forLiFePO4where as in case of C-LiFePO4that were 163, 144,more »118, and 70?mAh/g for C/5, C/3, C/2, and 1C, respectively. The capacity retention of pureLiFePO4was 69% after 25 cycles where as that of C-LiFePO4was around 97% after 50 cycles. These results indicate that the capacity and the rate capability improved significantly upon carbon coating.« less

  19. Structural and Electrochemical Characterization of Pure LiFePO 4 and Nanocomposite C- LiFePO 4 Cathodes for Lithium Ion Rechargeable Batteries

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

    Kumar, Arun; Thomas, R.; Karan, N. K.; Saavedra-Arias, J. J.; Singh, M. K.; Majumder, S. B.; Tomar, M. S.; Katiyar, R. S.

    2009-01-01

    Pure lithium iron phosphate ( LiFePO 4 ) and carbon-coated LiFePO 4 (C- LiFePO 4 ) cathode materials were synthesized for Li-ion batteries. Structural and electrochemical properties of these materials were compared. X-ray diffraction revealed orthorhombic olivine structure. Micro-Raman scattering analysis indicates amorphous carbon, and TEM micrographs show carbon coating on LiFePO 4 particles. Ex situ Raman spectrum of C- LiFePO 4 at various stages of charging and discharging showed reversibility upon electrochemical cycling. The cyclic voltammograms of more » LiFePO 4 and C- LiFePO 4 showed only a pair of peaks corresponding to the anodic and cathodic reactions. The first discharge capacities were 63, 43, and 13?mAh/g for C/5, C/3, and C/2, respectively for LiFePO 4 where as in case of C- LiFePO 4 that were 163, 144, 118, and 70?mAh/g for C/5, C/3, C/2, and 1C, respectively. The capacity retention of pure LiFePO 4 was 69% after 25 cycles where as that of C- LiFePO 4 was around 97% after 50 cycles. These results indicate that the capacity and the rate capability improved significantly upon carbon coating. « less

  20. Iron-phosphorus relationships in Fe chlorisis of sorghum 

    E-Print Network [OSTI]

    Morales-Vargas, Dennis A

    1979-01-01

    soils, depending on the species or variety of plant grown. Wallace and Lunt (52) indicated that 25 to 30% of the earth's land surface is calcareous. A survey (31) in all states west of the Mississippi River to de- termine the estimated acreage of Fe... as decrease in the yields, whereas, the same quantities of P applied to so1ls with an initial react1on ranging between 3. 5 and 5. 8 may cause stimulation of plant growth and increase of y1elds. In experiments of Fe nutrition of plants at h1gh pH, De...

  1. SF 6432-FE Fixed Price Contracts Outside the US

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservation of Fe(II) byMultidayAlumni > The EnergyRyanPhysics LabSAP7/31/13 Page 1FE

  2. THE LICK/SDSS LIBRARY. II. [Ca/Fe] AND [Mg/Fe] IN F, G, AND K STARS FROM SDSS-DR7

    SciTech Connect (OSTI)

    Franchini, M.; Morossi, C.; Di Marcantonio, P.; Malagnini, M. L. [INAF-Osservatorio Astronomico di Trieste, Via G.B. Tiepolo 11, I-34131 Trieste (Italy); Chavez, M., E-mail: franchini@oats.inaf.it, E-mail: morossi@oats.inaf.it, E-mail: dimarcan@oats.inaf.it, E-mail: malagnini@oats.inaf.it, E-mail: mchavez@inaoep.mx [Instituto Nacional de Astrofisica, Optica y Electronica, Luis Enrique Erro 1, 72840 Tonantzintla, Puebla (Mexico)

    2011-04-01

    We analyzed the spectra of 17,600 F, G, and K stars extracted from the seventh Sloan Digital Sky Survey Data Release (SDSS-DR7) database in order to derive ([{alpha}/Fe]), [Ca/Fe], and [Mg/Fe] ratios. Particular attention has been devoted to estimating homogeneous and self-consistent atmospheric parameter values, T{sub eff}, log g, and [Fe/H], by comparing synthetic and observational Lick/SDSS indices. We present results for the sub-sample of more than 4000 spectra whose overall quality allowed us to derive fairly accurate stellar atmospheric parameter values and, therefore, reliable abundance ratios. A Monte Carlo approach was adopted to evaluate both the errors in the observational Lick/SDSS indices and in the derived parameter estimates. The analysis of the trends of [Ca/Fe] and [Mg/Fe] versus [Fe/H] pointed out that (1) the [Ca/Fe] and [Mg/Fe] ratios increase with decreasing [Fe/H] with different slopes reaching maximum average levels of +0.25 and +0.40 dex at [Fe/H] {approx_equal} -1.75, respectively; (2) our sample contains, at a given [Fe/H], stars characterized by significantly different amounts of {alpha}-enhancement, thus belonging to different Galactic populations; and (3) the analyzed sample shows a predominance of thick disk stars for [Fe/H] > - 0.5 and the presence of stars belonging to the 'high-{alpha}' halo population for -2.0 < [Fe/H] <-0.5.

  3. The Pd/Fe Interface in the Epitaxial System Pd/Fe/GaAs(001)- 4 x 6

    SciTech Connect (OSTI)

    Budnik, P.S.; Gordon, R.A.; Crozier, E.D.

    2007-01-18

    Magnetic properties of thin magnetic films are strongly affected by the nature of the interface between magnetic and non-magnetic layers. In spintronic devices the extent to which spins are scattered at an interface depends upon interfacial roughness, alloying, and impurities. We present a polarization-dependent XAFS study of a 1Pd/9Fe/GaAs(001)-(4 x 6) structure grown in situ in the MBE facility at the PNC/XOR, APS. To increase the interfacial roughness, the 1ML Pd was grown on the 9 ML Fe without first sputtering and annealing the Fe. An estimate of interfacial roughness, evidence for formation of Pd islands, their height, and the amount of As floating to the Pd surface from the GaAs are given.

  4. k-space spin filtering effect in the epitaxial Fe/Au/Fe/GaAs(001) spin-valve

    SciTech Connect (OSTI)

    Hervé, M.; Tricot, S.; Claveau, Y.; Delhaye, G.; Lépine, B.; Di Matteo, S.; Schieffer, P.; Turban, P., E-mail: pascal.turban@univ-rennes1.fr [Département Matériaux et Nanosciences, Institut de Physique de Rennes, UMR 6251, CNRS-Université de Rennes 1, Campus de Beaulieu, Bât 11E, 35042 Rennes cedex (France)

    2013-11-11

    The hot-electron magnetotransport of epitaxial Fe/Au/Fe/GaAs(001) spin-valves is investigated by ballistic-electron magnetic microscopy. A magnetocurrent amplitude larger than 500% is observed at room temperature close to the Schottky barrier energy. Remarkably, this magnetocurrent is not significantly affected by the thickness reduction of ferromagnetic films, down to 5 atomic layers of the Fe(001) top electrode. This rather suggests a dominant interfacial spin-filtering effect. Finally, the magnetocurrent is strongly reduced when the effective mass of the semiconductor collector is increased. These observations are consistent with recent theoretical prediction of k-space spin-filtering effect in epitaxial spin-valves attached to a semiconducting lead.

  5. The effect of Fe-Rh alloying on CO hydrogenation to C2+ oxygenates

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

    Palomino, Robert; Magee, Joseph W.; Llorca, Jordi; Senanayake, Sanjaya D.; White, Michael G.

    2015-05-20

    A combination of reactivity and structural studies using X-ray diffraction (XRD), pair distribution function (PDF), and transmission electron microscopy (TEM) was used to identify the active phases of Fe-modified Rh/TiO2 catalysts for the synthesis of ethanol and other C2+ oxygenates from CO hydrogenation. XRD and TEM confirm the existence of Fe–Rh alloys for catalyst with 1–7 wt% Fe and ~2 wt% Rh. Rietveld refinements show that FeRh alloy content increases with Fe loading up to ~4 wt%, beyond which segregation to metallic Fe becomes favored over alloy formation. Catalysts that contain Fe metal after reduction exhibit some carburization as evidencedmore »by the formation of small amounts of Fe3C during CO hydrogenation. Analysis of the total Fe content of the catalysts also suggests the presence of FeOx also increased under reaction conditions. Reactivity studies show that enhancement of ethanol selectivity with Fe loading is accompanied by a significant drop in CO conversion. Comparison of the XRD phase analyses with selectivity suggests that higher ethanol selectivity is correlated with the presence of Fe–Rh alloy phases. As a result, the interface between Fe and Rh serves to enhance the selectivity of ethanol, but suppresses the activity of the catalyst which is attributed to the blocking or modifying of Rh active sites.« less

  6. Search for 14.4 keV solar axions from M1 transition of Fe-57 with CUORE crystals

    E-Print Network [OSTI]

    Alessandria, F.

    2014-01-01

    to JCAP Search for 14.4 keV solar axions from M1 transitionfor useful discussion about solar core 57 Fe content.excitation of 57 Fe in the solar core. The isotope 57 Fe is

  7. Transport measurements of FeAs superconductors in the 150T single...

    Office of Scientific and Technical Information (OSTI)

    Transport measurements of FeAs superconductors in the 150T single-turn magnet Citation Details In-Document Search Title: Transport measurements of FeAs superconductors in the 150T...

  8. SEMI-ANNUAL REPORTS FOR TEXAS LNG - TEXAS LNG - FTA - FE DKT...

    Office of Environmental Management (EM)

    TEXAS LNG - TEXAS LNG - FTA - FE DKT. NO. 13-160-LNG - 3443 SEMI-ANNUAL REPORTS FOR TEXAS LNG - TEXAS LNG - FTA - FE DKT. NO. 13-160-LNG - 3443 October 2014 April 2015 More...

  9. SEMI-ANNUAL REPORTS FOR Cameron LNG, LLC - FE Dkt. No. 15-36...

    Energy Savers [EERE]

    Cameron LNG, LLC - FE Dkt. No. 15-36-LNG - ORDER 3680 SEMI-ANNUAL REPORTS FOR Cameron LNG, LLC - FE Dkt. No. 15-36-LNG - ORDER 3680 NO REPORTS RECEIVED More Documents &...

  10. The Effects of Hydrocarbons on NOx Reduction over Fe-based SCR...

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

    on NOx Reduction over Fe-based SCR Catalyst Study of effects of hydrocarbons on ammonia storage and NOx reduction over a commercial Fe-zeolite SCR catalyst to understand...

  11. Stability of uranium incorporated into Fe(hydr)oxides under fluctuating redox conditions

    E-Print Network [OSTI]

    Stewart, B.D.

    2009-01-01

    by interaction with goethite, lepidocrocite, muscovite, andM. Reduction of U(VI) in goethite (alpha-FeOOH) suspensionsmM Fe(II) k F=ferrihydrite, G=goethite, L=lepidocrocite, M=

  12. Immobilization of 99-Technetium (VII) by Fe(II)-Goethite and Limited Reoxidation

    E-Print Network [OSTI]

    Um, Wooyong

    2013-01-01

    of Technetium-99 by Fe(II)-goethite; PNNL- 19833; PacificTransformation of magnetite to goethite under alkaline pHisotope variation among goethite (alpha- FeOOH) and the

  13. Technology Implimentation Plan - ATF FeCrAl Cladding for LWR Application

    SciTech Connect (OSTI)

    Snead, Mary A.; Snead, Lance; Terrani, Kurt A.; Field, Kevin G.; Worrall, Andrew; Robb, Kevin R.; Yamamoto, Yukinori; Powers, Jeffrey J.; Dryepondt, Sebastien N.; Pint, Bruce A.; Hu, Xunxiang

    2015-06-01

    Technology implimentation plan for FeCrAl development under the FCRD Advanced Fuel program. The document describes the activities required to get FeCrAl clad ready for LTR testing

  14. SEMI-ANNUAL REPORTS FOR LAKE CHARLES EXPORTS, LLC - FE DKT. NO...

    Office of Environmental Management (EM)

    LAKE CHARLES EXPORTS, LLC - FE DKT. NO. 11-59-LNG - ORDER 3324 SEMI-ANNUAL REPORTS FOR LAKE CHARLES EXPORTS, LLC - FE DKT. NO. 11-59-LNG - ORDER 3324 October 2013 April 2014...

  15. SEMI-ANNUAL REPORTS FOR ALASKA LNG PROJECT, LLC - FE DKT NO....

    Energy Savers [EERE]

    ALASKA LNG PROJECT, LLC - FE DKT NO. 14-96-LNG - ORDER 3643 (NFTA) SEMI-ANNUAL REPORTS FOR ALASKA LNG PROJECT, LLC - FE DKT NO. 14-96-LNG - ORDER 3643 (NFTA) October 2015 More...

  16. SEMI-ANNUAL REPORTS FOR GOLDEN PASS PRODUCTS LLC - FE DKT. NO...

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

    - GULF LNG LIQUEFACTION COMPANY, LLC - FE DKT. NO. 12-47-LNG - ORDER 3104 SEMI-ANNUAL REPORTS FOR SOUTHERN LNG COMPANY - FE DKT. NO. 12-54-LNG - ORDER 3106 Semi-annual Reports for...

  17. SEMI-ANNUAL REPORTS FOR GASFIN DEVELOPMENT USA, LLC - FE DKT...

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

    GASFIN DEVELOPMENT USA, LLC - FE DKT. NO. 13-06-LNG - ORDER 3253 SEMI-ANNUAL REPORTS FOR GASFIN DEVELOPMENT USA, LLC - FE DKT. NO. 13-06-LNG - ORDER 3253 April 2013 October 2013...

  18. Preservation of Fe(II) by Carbon-Rich Matrices in Hydrothermal...

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

    Preservation of Fe(II) by Carbon-Rich Matrices in Hydrothermal Plumes Preservation of Fe(II) by Carbon-Rich Matrices in Hydrothermal Plumes Print Wednesday, 29 April 2009 00:00...

  19. Accelerated Thermal Aging of Fe-Zeolite SCR Catalysts Using an...

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

    Thermal Aging of Fe-Zeolite SCR Catalysts Using an Engine-Based Systems Approach Accelerated Thermal Aging of Fe-Zeolite SCR Catalysts Using an Engine-Based Systems Approach This...

  20. The passivation of calcite by acid mine water. Column experiments with Fe(III)- SO4-H+ and Fe(III)-Cl-H+ solutions at pH 2

    E-Print Network [OSTI]

    Boi, Marco

    2010-01-01

    transformation into goethite and jarosite. Geochimica etwith respect to goethite, hematite and schwertmannite (Fe(+ solutions. Schwertmannite and goethite appeared as the Fe(

  1. Important role of the non-uniform Fe distribution for the ferromagnetism in group-IV-based ferromagnetic semiconductor GeFe

    SciTech Connect (OSTI)

    Wakabayashi, Yuki K.; Ohya, Shinobu; Ban, Yoshisuke; Tanaka, Masaaki [Department of Electrical Engineering and Information Systems, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)

    2014-11-07

    We investigate the growth-temperature dependence of the properties of the group-IV-based ferromagnetic semiconductor Ge{sub 1?x}Fe{sub x} films (x?=?6.5% and 10.5%), and reveal the correlation of the magnetic properties with the lattice constant, Curie temperature (T{sub C}), non-uniformity of Fe atoms, stacking-fault defects, and Fe-atom locations. While T{sub C} strongly depends on the growth temperature, we find a universal relationship between T{sub C} and the lattice constant, which does not depend on the Fe content x. By using the spatially resolved transmission-electron diffractions combined with the energy-dispersive X-ray spectroscopy, we find that the density of the stacking-fault defects and the non-uniformity of the Fe concentration are correlated with T{sub C}. Meanwhile, by using the channeling Rutherford backscattering and particle-induced X-ray emission measurements, we clarify that about 15% of the Fe atoms exist on the tetrahedral interstitial sites in the Ge{sub 0.935}Fe{sub 0.065} lattice and that the substitutional Fe concentration is not correlated with T{sub C}. Considering these results, we conclude that the non-uniformity of the Fe concentration plays an important role in determining the ferromagnetic properties of GeFe.

  2. Pair potential for FeHe N. Juslin *, K. Nordlund

    E-Print Network [OSTI]

    Nordlund, Kai

    formation and migration. Ab initio data for short range Fe­He dimer interaction is used to describe the high collision cascades have been extensively studied with MD simulations to determine primary damage formation shows that a pair potential is enough to describe simple He defects and migration of He in iron

  3. QER- Comment of Sustainable Santa Fe Programs Manager

    Broader source: Energy.gov [DOE]

    At the City of Santa Fe we have had difficulty in getting energy usage data from the investor-owned utility to be able to track progress towards energy use and greenhouse gas reduction goals. It would be helpful if that information were required to be publicly available at the Zip code level. Thanks.

  4. RDX degradation using an integrated Fe(0)-microbial treatment approach

    E-Print Network [OSTI]

    Alvarez, Pedro J.

    RDX degradation using an integrated Fe(0)-microbial treatment approach M.J. Wildman and P recalci- trance to microbial degradation, low volatility (dimensionless Henry's constant, H' = 2 × 10 attractive for in situ remedia- tion in that they conserve energy and water, and through long-term low

  5. Spin glass behavior in FeAl2 

    E-Print Network [OSTI]

    Lue, CS; Oner, Y.; Naugle, Donald G.; Ross, JH.

    2001-01-01

    and do not exhibit the be- havior attributed to rare-earth and actinide systems. FeAl2, however, clearly shows local-moment behavior leading to a spin-glass freezing at low temperatures. The resistivity of this material is large, comparable in size...

  6. Psychology Taster Days in Schools and FE Colleges (ID:317)

    E-Print Network [OSTI]

    Martin, Ralph R.

    Psychology Taster Days in Schools and FE Colleges (ID:317) Outline The University's Psychology department brings its students and staff to local schools and colleges to discuss studying psychology Psychology at Higher Education level. A pre-planned programme of events will focus on Psychology as a Science

  7. Vapor Phase Synthesis and Characterization of -FeSi Nanowires

    E-Print Network [OSTI]

    Walsworth, Ronald L.

    Vapor Phase Synthesis and Characterization of - FeSi Nanowires Lian Ouyang, Elizabeth S. Thrall, Mandar M. Deshmukh, and Hongkun Park Over the past decade, one-dimensional inorganic nanostructures have emerged as promising materials for fundamental studies and possible technological applications.[1

  8. ELECTRON-CAPTURE SUPERNOVAE AS SOURCES OF {sup 60}Fe

    SciTech Connect (OSTI)

    Wanajo, Shinya [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Janka, Hans-Thomas; Mueller, Bernhard, E-mail: shinya.wanajo@nao.ac.jp [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, D-85748 Garching (Germany)

    2013-09-01

    We investigate the nucleosynthesis of the radionuclide {sup 60}Fe in electron-capture supernovae (ECSNe). The nucleosynthetic results are based on a self-consistent, two-dimensional simulation of an ECSN as well as models in which the densities are systematically increased by some factors (low-entropy models). {sup 60}Fe is found to be appreciably made in neutron-rich ejecta during the nuclear quasi-equilibrium phase with greater amounts being produced in the lower-entropy models. Our results, combining them with the yields of core-collapse supernovae in the literature, suggest that ECSNe account for at least 4%-30% of live {sup 60}Fe in the Milky Way. ECSNe co-produce neutron-rich isotopes, {sup 48}Ca, {sup 50}Ti, {sup 54}Cr, some light trans-iron elements, and possibly weak r-process elements including some radionuclides such as {sup 93}Zr, {sup 99}Tc, and {sup 107}Pd, whose association with {sup 60}Fe might have been imprinted in primitive meteorites or in the deep ocean crust on the Earth.

  9. FE-Analysen zur Thermoermdung Test-und Feldzyklen

    E-Print Network [OSTI]

    Berlin,Technische Universität

    LIVE AG 1 -AG 2 FE-Analysen zur Thermoermüdung Test- und Feldzyklen R. Dudek, R. Döring, B #12;LIVE different SAC creep laws: Steady State Creep (after Schubert, SAC405 and Röllig/Wiese SAC xx) Creep properties of SAC 407 show much higher creep resistance than SAC xx SAC 305 bulk averaged values

  10. High strength-high conductivity Cu--Fe composites produced by powder compaction/mechanical reduction

    DOE Patents [OSTI]

    Verhoeven, John D. (Ames, IA); Spitzig, William A. (Ames, IA); Gibson, Edwin D. (Ames, IA); Anderson, Iver E. (Ames, IA)

    1991-08-27

    A particulate mixture of Cu and Fe is compacted and mechanically reduced to form an "in-situ" Cu-Fe composite having high strength and high conductivity. Compaction and mechanical reduction of the particulate mixture are carried out at a temperature and time at temperature selected to avoid dissolution of Fe into the Cu matrix particulates to a harmful extent that substantially degrades the conductivity of the Cu-Fe composite.

  11. High strength-high conductivity Cu-Fe composites produced by powder compaction/mechanical reduction

    DOE Patents [OSTI]

    Verhoeven, J.D.; Spitzig, W.A.; Gibson, E.D.; Anderson, I.E.

    1991-08-27

    A particulate mixture of Cu and Fe is compacted and mechanically reduced to form an ''in-situ'' Cu-Fe composite having high strength and high conductivity. Compaction and mechanical reduction of the particulate mixture are carried out at a temperature and time at temperature selected to avoid dissolution of Fe into the Cu matrix particulates to a harmful extent that substantially degrades the conductivity of the Cu-Fe composite. 5 figures.

  12. Two-band model of -prime phase formation in Fe-Cr. Par Olsson1

    E-Print Network [OSTI]

    Nordlund, Kai

    of ferritic-martensitic stainless steel. Fe-Cr forms a perfect ferro-magnetic alloy for Cr concentrations up

  13. Structural and Mössbauer spectroscopic study of Fe-Ni alloy nanoparticles

    SciTech Connect (OSTI)

    Kumar, Asheesh; Banerjee, S. Sudarsan, V.; Meena, S. S.

    2014-04-24

    Nano-crystalline Fe-Ni alloys have been synthesized in ethylene glycol medium. Based on XRD studies it is confirmed that, in these alloys Fe atoms are incorporated at Ni site to form Ni-Fe solid solutions. Mössbauer studies have established that for alloy particles having smaller size there is significant concentration of two different types of paramagnetic Fe species and their relative concentration decreased with increase in particle size.

  14. Combined Microbial-Fe(0) Treatment Systems 1 1058-8337/00/$.50

    E-Print Network [OSTI]

    Alvarez, Pedro J.

    produces cathodic H2 when corroded by water. The preferential colonization of Fe(0) suggests- valent iron (Fe(0)) is submerged in anoxic water, hydro- gen gas is produced via cathodic depolarizationCombined Microbial-Fe(0) Treatment Systems 1 1058-8337/00/$.50 © 2000 by Battelle Memorial

  15. Importance of Doping and Frustration in Itinerant Fe-doped Cr2Al

    SciTech Connect (OSTI)

    Susner, Michael A; Parker, David S; Safa-Sefat, Athena

    2015-01-01

    We have performed an experimental and theoretical study comparing the effects of Fe-doping of Cr2Al, an antiferromagnet with a N el temperature of 670 K, with known results on Fe-doping of antiferromagnetic bcc Cr. (Cr1-xFex)2Al materials are found to exhibit a rapid suppression of antiferromagnetic order with the presence of Fe, decreasing TN to 170 K for x=0.10. Antiferromagnetic behavior disappears entirely at x 0.125 after which point increasing paramagnetic behavior is exhibited. This is unlike the effects of Fe doping of bcc antiferromagnetic Cr, in which TN gradually decreases followed by the appearance of a ferromagnetic state. Theoretical calculations explain that the Cr2Al-Fe suppression of magnetic order originates from two effects: the first is band narrowing caused by doping of additional electrons from Fe substitution that weakens itinerant magnetism; the second is magnetic frustration of the Cr itinerant moments in Fe-substituted Cr2Al. In pure-phase Cr2Al, the Cr moments have an antiparallel alignment; however, these are destroyed through Fe substitution and the preference of Fe for parallel alignment with Cr. This is unlike bulk Fe-doped Cr alloys in which the Fe anti-aligns with the Cr atoms, and speaks to the importance of the Al atoms in the magnetic structure of Cr2Al and Fe-doped Cr2Al.

  16. Hydrogen adsorption on Pd/TiFe (110) surface S.E. Kulkovaa

    E-Print Network [OSTI]

    Kim, Jai Sam

    Hydrogen adsorption on Pd/TiFe (110) surface S.E. Kulkovaa , S.V. Eremeeva,b,*, V.E. Egorushkinc February 2003 by E.L. Ivchenko Abstract Adsorption of hydrogen on the TiFe (110) surface covered. Electronic band structure 1. Introduction The TiFe alloy is an excellent material for hydrogen storage [1

  17. The local structure and ferromagnetism in Fe-implanted SrTiO? single crystals

    SciTech Connect (OSTI)

    Lobacheva, O. Chavarha, M.; Yiu, Y. M.; Sham, T. K.; Goncharova, L. V.

    2014-07-07

    We report a connection between the local structure of low-level Fe impurities and vacancies as the cause of ferromagnetic behavior observed in strontium titanate single crystals (STO), which were implanted with Fe and Si ions at different doses then annealed in oxygen. The effects of Fe doping and post-implantation annealing of STO were studied by X-ray Absorption Near Edge Structure (XANES) spectroscopy and Superconducting Quantum Interference Device magnetometry. XANES spectra for Fe and Ti K- and L-edge reveal the changes in the local environment of Fe and Ti following the implantation and annealing steps. The annealing in oxygen atmosphere partially healed implantation damages and changed the oxidation state of the implanted iron from metallic Fe? to Fe²?/Fe³? oxide. The STO single crystals were weak ferromagnets prior to implantation. The maximum saturation moment was obtained after our highest implantation dose of 2×10¹? Fe atom/cm², which could be correlated with the metallic Fe? phases in addition to the presence of O/Ti vacancies. After recrystallization annealing, the ferromagnetic response disappears. Iron oxide phases with Fe²? and Fe³? corresponding to this regime were identified and confirmed by calculations using Real Space Multiple Scattering program (FEFF9).

  18. Temperature dependence of magnetoelastic properties of Fe100?xSix (5 < x < 20)

    SciTech Connect (OSTI)

    Petculescu, G.; Lambert, P.K.; Clark, A.E.; Hathaway, K.B.; Xing, Qingfeng; Lograsso, Tom; Restorff, J.B.; Wun-Fogle, M.

    2012-02-29

    Tetragonal magnetostriction (??,2) and elastic constants (c?, c44, and c11) for Fe100?xSix were measured as a function of temperature (T). Compositions corresponding to the disordered A2 (x?=?5), ordered D03 (x?=?19.8), and mixed (x?=?11.6) phases, were investigated. The magnetoelastic coupling (?b1) was determined for 77 < T < 300?K and compared with those of Fe-Ga, Fe-Ge, and Fe-Al. Both ??,2(T) and ?b1(T) of Fe-Si behave similarly to those of Fe-Ge, while other notable differences exist between the measured properties of Fe-Si and those of the other three alloys. Due to the early establishment of short range order, Fe-Si exhibits a positive, although small, slope in ??,2(T) at 5 at. % Si, and a remarkable drop in ?b1 before the solubility limit. The weaker softening of the tetragonal shear modulus with the addition of Si and the lack of strong anharmonic effects in the Fe-Si lattice inferred from the weak T-dependence of all the moduli suggest that Fe-Si exhibits more structural stability than the other three alloys. The distinctive behavior is likely due to the smaller size of Si compared to the sizes of Ga, Ge and Al, and therefore to the effect of the larger size difference between Fe and Si in the Fe-Si lattice.

  19. Domain Engineering for Enhanced Ferroelectric Properties of Epitaxial (001) BiFeO Thin Films

    E-Print Network [OSTI]

    Eom, Chang Beom

    Domain Engineering for Enhanced Ferroelectric Properties of Epitaxial (001) BiFeO Thin Films By Ho of conventional Ti-rich lead zirconia titanate, suggested BiFeO3 as a strong candidate for lead-free nonvolatile are simultaneously improved by domain engineering. For the demonstration of the domain variant selection in BiFeO3

  20. Magnetic behaviour of the rare earth binary R-Fe alloys

    SciTech Connect (OSTI)

    Cabral, F.A.O.; Turtelli, R.S.; Gama, S.; Machado, F.L.A. )

    1989-09-01

    Thermomagnetic analysis and coercive field measurements in rare-earth-rich alloys of the systems Fe-Ce, Fe-Pr and Fe-Nd suggest the presence of two different magnetically hard phases in all these systems. These phases can be metastable and their magnetic properties are strongly affected by heat-treatments at 600{sup 0}C.

  1. Precision Fe Kalpha and Fe Kbeta Line Spectroscopy of the Seyfert 1.9 Galaxy NGC 2992 with Suzaku

    E-Print Network [OSTI]

    Yaqoob, T; Griffiths, R E; Haba, Y; Inoue, H; Itoh, T; Kelley, R; Kokubun, M; Markowitz, A; Mushotzky, R; Okajima, T; Ptak, A; Reeves, J; Serlemitsos, P J; Takahashi, T; Terashima, Y; Yaqoob, Tahir; Murphy, Kendrah D.; Griffiths, Richard E.; Haba, Yoshito; Inoue, Hajime; Itoh, Takeshi; Kelley, Richard; Kokubun, Motohide; Markowitz, Alex; Mushotzky, Richard; Okajima, Takashi; Ptak, Andrew; Reeves, James; Serlemitsos, Peter J.; Takahashi, Tadayuki; Terashima, and Yuichi

    2006-01-01

    We present detailed time-averaged X-ray spectroscopy in the 0.5--10 keV band of the Seyfert~1.9 galaxy NGC 2992 with the Suzaku X-ray Imaging Spectrometers (XIS). We model the complex continuum in detail. There is an Fe K line emission complex that we model with broad and narrow lines and we show that the intensities of the two components are decoupled at a confidence level >3sigma. The broad Fe K line has an EW of 118 (+32,-61) eV and could originate in an accretion disk (with inclination angle greater than ~30 degrees). The narrow Fe Kalpha line has an EW of 163 (+47,-26) eV and is unresolved FWHM <4090 km/s) and likely originates in distant matter. The absolute flux in the narrow line implies that the column density out of the line-of-sight could be much higher than measured in the line-of-sight, and that the mean (historically-averaged) continuum luminosity responsible for forming the line could be a factor of several higher than that measured from the data. We also detect the narrow Fe Kbeta line with...

  2. A synthesis of LiFePO{sub 4} starting from FePO{sub 4} under reducing atmosphere

    SciTech Connect (OSTI)

    Prosini, Pier Paolo [ENEA, Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Casaccia Research Centre, Via Anguillarese 301, 00123 Santa Maria di Galeria, Rome, Italy and DInESto, Drive the Innovation in Energy Storage, Via Provin (Italy); Cento, Cinzia; Masci, Amedeo; Carewska, Maria; Gislon, Paola [ENEA, Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Casaccia Research Centre, Via Anguillarese 301, 00123 Santa Maria di Galeria, Rome (Italy)

    2014-06-19

    A fast and easy way to produce LiFePO{sub 4} starting from FePO{sub 4}, used as iron and phosphorus source, is proposed. 5% hydrogen is employed as a reducing agent and various compounds containing lithium as lithiation agents. The selected lithiation agents included: LiCl, CH{sub 3}COOLi, LiOH, Li{sub 2}S, LiH, and Li{sub 2}CO{sub 3}. Solid state synthesis is used for the LiFePO{sub 4} preparation and the so obtained materials are structurally characterized by XRD. The materials are used to fabricate composite electrode and their specific capacity is evaluated by low rate galvanostatic charge/discharge cycles (C/10 rate). Among the various lithium salts, the acetate give rise to the LiFePO{sub 4} with the best electrochemical performance. The morphology of this material is further investigated by SEM microscopy and the specific capacity is evaluated as a function of the discharge rate and the cycle number.

  3. Ultra-thin L1{sub 0}-FePt for perpendicular anisotropy L1{sub 0}-FePt/Ag/[Co/Pd]{sub 30} pseudo spin valves

    SciTech Connect (OSTI)

    Ho, Pin; Chow, Gan Moog; Chen, Jing-Sheng, E-mail: msecj@nus.edu.sg [Department of Materials Science and Engineering, National University of Singapore, Singapore 117576 (Singapore); Han, Guchang [Data Storage Institute, Agency of Science, Technology and Research (A-STAR), Singapore 117608 (Singapore); He, Kaihua [School of Mathematics and Physics, China University of Geosciences, Wuhan 430074 (China)

    2014-05-07

    Perpendicular anisotropy L1{sub 0}-FePt/Ag/[Co/Pd]{sub 30} pseudo spin valves (PSVs) with ultra-thin L1{sub 0}-FePt alloy free layer possessing high anisotropy and thermal stability have been fabricated and studied. The thickness of the L1{sub 0}-FePt layer was varied between 2 and 4?nm. The PSV became increasingly decoupled with reduced L1{sub 0}-FePt thickness due to the larger difference between the coercivity of the L1{sub 0}-FePt and [Co/Pd]{sub 30} films. The PSV with an ultra-thin L1{sub 0}-FePt free layer of 2?nm displayed a high K{sub u} of 2.21?×?10{sup 7}?ergs/cm{sup 3}, high thermal stability of 84 and a largest giant magnetoresistance of 0.54%.

  4. Evolution of stable and metastable phases and coercivity in rare-earth-rich alloys of the Fe-Nd and Fe-Pr systems

    SciTech Connect (OSTI)

    Cabral, F.A.O. ); Gama, S. )

    1990-09-01

    The authors have studied eutectic alloys of the Fe-Nd and Fe-Pr systems regarding their magnetic behavior in the as-cast state and heat-treated at 600 C for different periods. In both systems the initial precipitation of a metastable phase is observed. This phase transforms into Fe{sub 17}Nd{sub 2} and this finally into a second phase with Fe{sub 17}Nd{sub 5} stoichiometry that is stable. For the Fe-Pr system the precipitation of two metastable phases that transform into the stable Fe{sub 17}Pr{sub 2} is observed. The authors have also measured the influence of these transformations on the coercivity of these alloys.

  5. Nuclear resonance vibrational spectroscopy reveals the FeS cluster composition and active site vibrational properties of an O2-tolerant NAD+-reducing [NiFe] hydrogenase

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

    Lauterbach, Lars; Wang, Hongxin; Horch, Marius; Gee, Leland B.; Yoda, Yoshitaka; Tanaka, Yoshihito; Zebger, Ingo; Lenz, Oliver; Cramer, Stephen P.

    2014-10-30

    Hydrogenases are complex metalloenzymes that catalyze the reversible splitting of molecular hydrogen into protons and electrons essentially without overpotential. The NAD+-reducing soluble hydrogenase (SH) from Ralstonia eutropha is capable of H2 conversion even in the presence of usually toxic dioxygen. The molecular details of the underlying reactions are largely unknown, mainly because of limited knowledge of the structure and function of the various metal cofactors present in the enzyme. Here, all iron-containing cofactors of the SH were investigated by 57Fe specific nuclear resonance vibrational spectroscopy (NRVS). Our data provide experimental evidence for one [2Fe2S] center and four [4Fe4S] clusters, whichmore »is consistent with the amino acid sequence composition. Only the [2Fe2S] cluster and one of the four [4Fe4S] clusters were reduced upon incubation of the SH with NADH. This finding explains the discrepancy between the large number of FeS clusters and the small amount of FeS cluster-related signals as detected by electron paramagnetic resonance spectroscopic analysis of several NAD+-reducing hydrogenases. For the first time, Fe–CO and Fe–CN modes derived from the [NiFe] active site could be distinguished by NRVS through selective 13C labeling of the CO ligand. This strategy also revealed the molecular coordinates that dominate the individual Fe–CO modes. The present approach explores the complex vibrational signature of the Fe–S clusters and the hydrogenase active site, thereby showing that NRVS represents a powerful tool for the elucidation of complex biocatalysts containing multiple cofactors.« less

  6. Influence of electrolyte chemistry on the structure and reactivity of Fe(III) precipitates generated by Fe(0) electrocoagulation: Implications for low-cost arsenic treatment

    E-Print Network [OSTI]

    van Genuchten, Case Michael

    2013-01-01

    systems contaminated by acid mine drainage, aqueous Fe(III)from the Carnoules acid mine drainage, France: Comparisonin the carnoulbs acid mine drainage, France. A XANES, XRD,

  7. Improved gas sensing and dielectric properties of Fe doped hydroxyapatite thick films: Effect of molar concentrations

    SciTech Connect (OSTI)

    Mene, Ravindra U. [PDEA's, Annasaheb Waghire College of Science, Arts and Commerce, Otur 412409, M.S. (India); School of Physical Sciences, Swami Ramanand Teerth Marathwada University, Nanded 431606, M.S. (India); Mahabole, Megha P. [School of Physical Sciences, Swami Ramanand Teerth Marathwada University, Nanded 431606, M.S. (India); Mohite, K.C. [Haribhai. V. Desai College, Pune 411002, M.S. (India); Khairnar, Rajendra S., E-mail: rskhairnarsps@gmail.com [School of Physical Sciences, Swami Ramanand Teerth Marathwada University, Nanded 431606, M.S. (India)

    2014-02-01

    Highlights: • We report improved gas sensing and dielectric characteristics of Fe ion exchanged HAp films. • Fe doped HAp film shows maximum gas response at relatively lower temperature. • Response and gas uptake capacity of sensors is improved for appropriate amount of Fe ions in HAp matrix. • Fe-HAp films exhibit remarkable improvement in dielectric properties compared to pure HAp. • Fe doped HAp films show significant improvement in gas sensing as well as in dielectric properties. - Abstract: In the present work Fe doped hydroxyapatite (Fe-HAp) thick films has been successfully utilized to improve the gas sensing as well as its dielectric properties. Initially, HAp nano powder is synthesized by chemical precipitation process and later on Fe ions are doped in HAp by ion exchange process. Structural and morphological modifications are observed by means of X-ray diffraction and scanning electron microscopy analysis. The sensing parameters such as operating temperature, response/recovery time and gas uptake capacity are experimentally determined. The Fe-HAp (0.05 M) film shows improved CO and CO{sub 2} gas sensing capacity at lower operating temperature compared to pure HAp. Moreover, variation of dielectric constant and dielectric loss for pure and Fe-HAp thick films are studied as a function of frequency in the range of 10 Hz–1 MHz. The study reveals that Fe doped HAp thick films improve the sensing and dielectric characteristics as compared to pure HAp.

  8. Oxide shell reduction and magnetic property changes in core-shell Fe nanoclusters under ion irradiation

    SciTech Connect (OSTI)

    Sundararajan, Jennifer A.; Kaur, Maninder; Qiang, You, E-mail: youqiang@uidaho.edu [Department of Physics, University of Idaho, Moscow, Idaho 83844 (United States); Jiang, Weilin [Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352 (United States); McCloy, John S. [School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington 99164 (United States)

    2014-05-07

    Ion irradiation effects are studied on the Fe-based core-shell nanocluster (NC) films with core as Fe and shell as Fe{sub 3}O{sub 4}/Fe{sub 3}N. These NC films were deposited on Si substrates to thickness of ?0.5 ?m using a NC deposition system. The films were irradiated at room temperature with 5.5?MeV Si{sup 2+} ions to ion fluences of 10{sup 15} and 10{sup 16} ions/cm{sup 2}. It is found that the irradiation induces grain growth, Fe valence reduction in the shell, and crystallization or growth of Fe{sub 3}N. The film retained its Fe-core and its ferromagnetic properties after irradiation. The nature and mechanism of oxide shell reduction and composition dependence after irradiation were studied by synthesizing additional NC films of Fe{sub 3}O{sub 4} and FeO?+?Fe{sub 3}N and irradiating them under the same conditions. The presence of nanocrystalline Fe is found to be a major factor for the oxide shell reduction. The surface morphologies of these films show dramatic changes in the microstructures due to cluster growth and agglomeration as a result of ion irradiation.

  9. Ferromagnetic interactions and martensitic transformation in Fe doped Ni-Mn-In shape memory alloys

    SciTech Connect (OSTI)

    Lobo, D. N.; Priolkar, K. R.; Emura, S.; Nigam, A. K.

    2014-11-14

    The structure, magnetic, and martensitic properties of Fe doped Ni-Mn-In magnetic shape memory alloys have been studied by differential scanning calorimetry, magnetization, resistivity, X-ray diffraction (XRD), and EXAFS. While Ni{sub 2}MnIn{sub 1?x}Fe{sub x} (0???x???0.6) alloys are ferromagnetic and non martensitic, the martensitic transformation temperature in Ni{sub 2}Mn{sub 1.5}In{sub 1?y}Fe{sub y} and Ni{sub 2}Mn{sub 1.6}In{sub 1?y}Fe{sub y} increases for lower Fe concentrations (y???0.05) before decreasing sharply for higher Fe concentrations. XRD analysis reveals presence of cubic and tetragonal structural phases in Ni{sub 2}MnIn{sub 1?x}Fe{sub x} at room temperature with tetragonal phase content increasing with Fe doping. Even though the local structure around Mn and Ni in these Fe doped alloys is similar to martensitic Mn rich Ni-Mn-In alloys, presence of ferromagnetic interactions and structural disorder induced by Fe affect Mn-Ni-Mn antiferromagnetic interactions resulting in suppression of martensitic transformation in these Fe doped alloys.

  10. The origin of [Fe II] emission in NGC 4151

    E-Print Network [OSTI]

    Turner, J E H; Chapman, S; Content, R; Done, C; Haynes, R; Lee, D; Morris, S; Turner, James E.H.; Allington-Smith, Jeremy; Chapman, Scott; Content, Robert; Done, Christine; Haynes, Roger; Lee, David; Morris, Simon

    2002-01-01

    The centre of NGC 4151 has been observed in the J-band with the SMIRFS integral field unit (IFU) on the UK Infrared Telescope. A map of [Fe II] emission is derived, and compared with the distributions of the optical narrow line region and radio jet. We conclude that, because the [Fe II] emission is associated more closely with the visible narrow-line region than with the radio jet, it arises mainly through photoionization of gas by collimated X-rays from the Seyfert nucleus. The velocity field and strength with respect to [Pa B] are found to be consistent with this argument. The performance of the IFU is considered briefly, and techniques for observation and data analysis are discussed.

  11. Exchange bias in Fe/Cr double superlattices.

    SciTech Connect (OSTI)

    Jiang, J. S.; Felcher, G. P.; Inomata, A.; Goyette, R.; Nelson, C.; Bader, S. D.

    1999-11-30

    Utilizing the oscillatory interlayer exchange coupling in Fe/Cr superlattices, we have constructed ''double superlattice'' structures where a ferromagnetic (F) and an antiferromagnetic (AF) Fe/Cr superlattice are coupled through a Cr spacer. The minor hysteresis loops in the magnetization are shifted from zero field, i.e., the F superlattice is exchange biased by the AF one. The double superlattices are sputter-deposited with (211) epitaxy and possess uniaxial in-plane magnetic anisotropy. The magnitude of the bias field is satisfactorily described by the classic formula for collinear spin structures. The coherent structure and insensitivity to atomic-scale roughness makes it possible to determine the spin distribution by polarized neutron reflectivity, which confirms that the spin structure is collinear. The magnetic reversal behavior of the double superlattices suggests that a realistic model of exchange bias needs to address the process of nucleating local reverse domains.

  12. Fe/V Redox Flow Battery Electrolyte Investigation and Optimization

    SciTech Connect (OSTI)

    Li, Bin; Li, Liyu; Wang, Wei; Nie, Zimin; Chen, Baowei; Wei, Xiaoliang; Luo, Qingtao; Yang, Zhenguo; Sprenkle, Vincent L.

    2013-05-01

    Recently invented Fe/V redox flow battery (IVBs) system has attracted more and more attentions due to its long-term cycling stability. In this paper, the factors (such as compositions, state of charge (SOC) and temperatures) influencing the stability of electrolytes in both positive and negative half-cells were investigated by an extensive matrix study. Thus an optimized electrolyte, which can be operated in the temperature ranges from -5oC to 50oC without any precipitations, was identified. The Fe/V flow cells using the optimized electrolytes and low-cost membranes exhibited satisfactory cycling performances at different temperatures. The efficiencies, capacities and energy densities of flow batteries with varying temperatures were discussed in detail.

  13. Kinetics of Fe(III)*EDTA reduction by ascorbic acid

    SciTech Connect (OSTI)

    Li, W.; Harkness, J.B.L.; Mendelsohn, M.H.

    1992-12-01

    The kinetics of the reduction of ferric chelate by ascorbic acid have been determined at a typical flue-gas scrubber-system operating temperature ({approximately}55{degrees}C). The ascorbic acid reaction has the same reduction rate expression as the reduction by bisulfite ions, namely, first order with respect to the concentrations of both Fe(III)*EDTA and monoionic species of ascorbic acid. The reaction rate isnegative first order with respect to Fe(II)*EDTA concentration. In the pH range of 6--8, reduction of the hydrolyzed form of the metal chelate compound was negligible. The rate constant for the ascorbic acid reduction reaction is almost 400 times larger than that for the bisulfite reduction reaction under the same reaction conditions. There was no contribution associated with the nonionized form of ascorbic acid.

  14. Kinetics of Fe(III)*EDTA reduction by ascorbic acid

    SciTech Connect (OSTI)

    Li, W.; Harkness, J.B.L.; Mendelsohn, M.H.

    1992-01-01

    The kinetics of the reduction of ferric chelate by ascorbic acid have been determined at a typical flue-gas scrubber-system operating temperature ([approximately]55[degrees]C). The ascorbic acid reaction has the same reduction rate expression as the reduction by bisulfite ions, namely, first order with respect to the concentrations of both Fe(III)*EDTA and monoionic species of ascorbic acid. The reaction rate isnegative first order with respect to Fe(II)*EDTA concentration. In the pH range of 6--8, reduction of the hydrolyzed form of the metal chelate compound was negligible. The rate constant for the ascorbic acid reduction reaction is almost 400 times larger than that for the bisulfite reduction reaction under the same reaction conditions. There was no contribution associated with the nonionized form of ascorbic acid.

  15. Spectroscopic study of Gd nanostructures quantum confined in Fe corrals

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

    Cao, R. X.; Sun, L.; Miao, B. F.; Li, Q. L.; Zheng, C.; Wu, D.; You, B.; Zhang, W.; Han, P.; Bader, S. D.; et al

    2015-07-10

    Low dimensional nanostructures have attracted attention due to their rich physical properties and potential applications. The essential factor for their functionality is their electronic properties, which can be modified by quantum confinement. Here the electronic states of Gd atom trapped in open Fe corrals on Ag(111) were studied via scanning tunneling spectroscopy. A single spectroscopic peak above the Fermi level is observed after Gd adatoms are trapped inside Fe corrals, while two peaks appear in empty corrals. The single peak position is close to the higher energy peak of the empty corrals. These findings, attributed to quantum confinement of themore »corrals and Gd structures trapped inside, are supported by tight-binding calculations. As a result, this demonstrates and provides insights into atom trapping in open corrals of various diameters, giving an alternative approach to modify the properties of nano-objects.« less

  16. Constraining FeLoBAL outflows from absorption line variability

    E-Print Network [OSTI]

    McGraw, S M; Hamann, F W; Capellupo, D M; Gallagher, S C; Brandt, W N

    2015-01-01

    FeLoBALs are a rare class of quasar outflows with low-ionization broad absorption lines (BALs), large column densities, and potentially large kinetic energies that might be important for `feedback' to galaxy evolution. In order to probe the physical properties of these outflows, we conducted a multiple-epoch, absorption line variability study of 12 FeLoBAL quasars spanning a redshift range between 0.7 and 1.9 over rest frame time-scales of approximately 10 d to 7.6 yr. We detect absorption line variability with greater than 8 sigma confidence in 3 out of the 12 sources in our sample over time-scales of 0.6 to 7.6 yr. Variable wavelength intervals are associated with ground and excited state Fe II multiplets, the Mg II 2796, 2803 doublet, Mg I 2852, and excited state Ni II multiplets. The observed variability along with evidence of saturation in the absorption lines favors transverse motions of gas across the line of sight (LOS) as the preferred scenario, and allows us to constrain the outflow distance from th...

  17. Spectral Models for Early Time SN 2011fe Observations

    E-Print Network [OSTI]

    Baron, E; Sullivan, M; Hsiao, E; Ellis, R S; Gal-Yam, A; Howell, D A; Nugent, P E; Dominguez, I; Krisciunas, K; Phillips, M M; Suntzeff, N; Wang, L; Thomas, R C

    2015-01-01

    We use observed UV through near IR spectra to examine whether SN 2011fe can be understood in the framework of Branch-normal SNe Ia and to examine its individual peculiarities. As a benchmark, we use a delayed-detonation model with a progenitor metallicity of Z_solar/20. We study the sensitivity of features to variations in progenitor metallicity, the outer density profile, and the distribution of radioactive nickel. The effect of metallicity variations in the progenitor have a relatively small effect on the synthetic spectra. We also find that the abundance stratification of SN 2011fe resembles closely that of a delayed detonation model with a transition density that has been fit to other Branch-normal Type Ia supernovae. At early times, the model photosphere is formed in material with velocities that are too high, indicating that the photosphere recedes too slowly or that SN 2011fe has a lower specific energy in the outer ~0.1 M_sun than does the model. We discuss several explanations for the discrepancies. ...

  18. Visualising Fe speciation diversity in ocean particulate samples by micro X-ray absorption near-edge spectroscopy

    E-Print Network [OSTI]

    @lbl.gov Environmental context. Iron-bearing particles in the ocean have attracted interest due to the role of iron to something manageable. The Western Subarctic Pacific particles were grouped into four main populations, each into three clusters: (1) Fe3þ -bearing clays þ Fe3þ oxyhydroxides, (2) Fe2þ silicates þ Fe3þ oxyhydroxides

  19. High-resolution velocity measurements on fully identified light nuclides produced in 56Fe + hydrogen and 56Fe + titanium systems

    E-Print Network [OSTI]

    P. Napolitani; K. -H. Schmidt; A. S. Botvina; F. Rejmund; L. Tassan-Got; C. Villagrasa

    2004-12-02

    New experimental results on the kinematics and the residue production are obtained for the interactions of 56Fe projectiles with protons and (nat)Ti target nuclei, respectively, at theincident energy of 1 A GeV. The titanium-induced reaction serves as a reference case for multifragmentation. Already in the proton-induced reaction, the characteristics of the isotopic cross sections and the shapes of the velocity spectra of light residues indicate that high thermal energy is deposited in the system during the collision. In the 56Fe+p system the high excitation seems to favour the onset of fast break-up decays dominated by very asymmetric partitions of the disassembling system. This configuration leads to the simultaneous formation of one or more light fragments together with one heavy residue.

  20. Crystallization Behavior, Nanostructure and Magnetic Properties of Melt-spun (Nd,Pr,Dy)2(Fe,Co,Mo)14B/-Fe Nanocomposite Magnets

    E-Print Network [OSTI]

    Garmestani, Hamid

    for 30 s at a heating rate1 Crystallization Behavior, Nanostructure and Magnetic Properties of Melt-spun (Nd,Pr,Dy)2(Fe,Co,Mo)14B/-Fe Nanocomposite Magnets B. Z. Cui 1, 2 *, K. Han 1 , Y. Zhang 3 , J. P. Liu 2 , H. Garmestani 1

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

    SciTech Connect (OSTI)

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

    2011-12-15

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

  2. FE ISOTOPE NUCLEOSYNTHESIS: CONSTRAINTS FROM FE ISOTOPIC ANALYSES OF PRESOLAR SILICATE GRAINS FROM ACFER 094. W. J. Ong and C. Floss. Laboratory for Space Sciences

    E-Print Network [OSTI]

    Floss, Christine

    FE ISOTOPE NUCLEOSYNTHESIS: CONSTRAINTS FROM FE ISOTOPIC ANALYSES OF PRESOLAR SILICATE GRAINS FROM information about fundamental astrophysical processes, such as stellar nucleosynthesis and galactic chemical evolution. Iron is of particular interest because of its importance in s-process nucleosynthesis. However

  3. In situ observation of defect annihilation in Kr ion-irradiated bulk Fe/amorphous-Fe 2 Zr nanocomposite alloy

    SciTech Connect (OSTI)

    Yu, K. Y.; Fan, Z.; Chen, Y.; Song, M.; Liu, Y.; Wang, H.; Kirk, M. A.; Li, M.; Zhang, X.

    2014-08-26

    Enhanced irradiation tolerance in crystalline multilayers has received significant attention lately. However, little is known on the irradiation response of crystal/amorphous nanolayers. We report on in situ Kr ion irradiation studies of a bulk Fe96Zr4 nanocomposite alloy. Irradiation resulted in amorphization of Fe2Zr and formed crystal/amorphous nanolayers. ?-Fe layers exhibited drastically lower defect density and size than those in large ?-Fe grains. In situ video revealed that mobile dislocation loops in ?-Fe layers were confined by the crystal/amorphous interfaces and kept migrating to annihilate other defects. This study provides new insights on the design of irradiation-tolerant crystal/amorphous nanocomposites.

  4. First principles study of Fe in diamond: A diamond-based half metallic dilute magnetic semiconductor

    SciTech Connect (OSTI)

    Benecha, E. M.; Lombardi, E. B.

    2013-12-14

    Half-metallic ferromagnetic ordering in semiconductors, essential in the emerging field of spintronics for injection and transport of highly spin polarised currents, has up to now been considered mainly in III–V and II–VI materials. However, low Curie temperatures have limited implementation in room temperature device applications. We report ab initio Density Functional Theory calculations on the properties of Fe in diamond, considering the effects of lattice site, charge state, and Fermi level position. We show that the lattice sites and induced magnetic moments of Fe in diamond depend strongly on the Fermi level position and type of diamond co-doping, with Fe being energetically most favorable at the substitutional site in p-type and intrinsic diamond, while it is most stable at a divacancy site in n-type diamond. Fe induces spin polarized bands in the band gap, with strong hybridization between Fe-3d and C-2s,2p bands. We further consider Fe-Fe spin interactions in diamond and show that substitutional Fe{sup +1} in p-type diamond exhibits a half-metallic character, with a magnetic moment of 1.0??{sub B} per Fe atom and a large ferromagnetic stabilization energy of 33?meV, an order of magnitude larger than in other semiconductors, with correspondingly high Curie temperatures. These results, combined with diamond's unique properties, demonstrate that Fe doped p-type diamond is likely to be a highly suitable candidate material for spintronics applications.

  5. Oxide Shell Reduction and Magnetic Property Changes in Core-Shell Fe Nanoclusters under Ion Irradiation

    SciTech Connect (OSTI)

    Sundararajan, Jennifer A.; Kaur, Maninder; Jiang, Weilin; McCloy, John S.; Qiang, You

    2014-02-12

    Ion irradiation effects are studied on the Fe-based core-shell nanocluster (NC) films with core as Fe and shell as Fe3O4/FeO. These NC films were were deposited on Si substrates to thickness of ~0.5 micrometers using a NC deposition system. The films were irradiated at room temperature with 5.5 MeV Si2+ ions to ion fluences of 1015 and 1016 ions/cm2. It is found that the irradiation induces grain growth, Fe valence reduction in the shell, and crystallization of Fe3N. The nature and mechanism of oxide shell reduction and composition dependence after irradiation were studied by synthesizing additional NC films of Fe3O4 and FeO+Fe3N and irradiating them under the same conditions. The presence of nanocrystalline Fe is found to be a major factor for the oxide shell reduction. The surface morphologies of these films show dramatic changes in the microstructures due to cluster growth and agglomeration as a result of ion irradiation.

  6. Aligned and exchange-coupled L1{sub 0} (Fe,Co)Pt-based magnetic films

    SciTech Connect (OSTI)

    Liu, Y.; George, T. A.; Skomski, R.; Sellmyer, D. J. [Department of Physics and Astronomy and Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, Nebraska 68588 (United States)

    2012-04-01

    Films of aligned L1{sub 0}-structure (Fe,Co)Pt with fcc Fe(Co,Pt) are synthesized by co-sputtering Fe, Co, and Pt on an (001) MgO substrate with in situ heating at 830 deg. C. The nanostructures and magnetic properties of the films are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and superconducting quantum interference device (SQUID). The compositions of the samples (Fe,Co){sub x}Pt{sub 1-x} are designed to maintain an atomic Fe: Co ratio of 65: 35 while increasing the Fe,Co content in each successive sample. In samples with low Fe and Co concentration, the XRD patterns exhibit three strong peaks, namely L1{sub 0} (Fe,Co)Pt (001), L1{sub 0} (Fe,Co)Pt (002), and MgO (002). A fourth peak is observed in samples with high Fe and Co concentration and identified as fcc (002). The XRD patterns confirm the formation of L1{sub 0}-ordered (Fe,Co)Pt and its epitaxial growth on MgO. TEM shows that the (Fe,Co)Pt films form isolated magnetic grains of about 100 nm in diameter. Hysteresis-loop measurements show that the increase of the Fe,Co concentration from 57.3 to 68.3 at % enhances the saturation magnetization M{sub s} from 1245 emu/cm{sup 3} to 1416 emu/cm{sup 3}, and the coercivity decreases from 32 kOe to 8.9 kOe. The nominal maximum energy product per grain is 64 MGOe.

  7. Towards tailoring the magnetocaloric response in FeRh-based ternary compounds

    SciTech Connect (OSTI)

    Barua, Radhika Jiménez-Villacorta, Félix; Lewis, L. H.

    2014-05-07

    In this work, we demonstrate that the magnetocaloric response of FeRh-based compounds may be tailored for potential magnetic refrigeration applications by chemical modification of the FeRh lattice. Alloys of composition Fe(Rh{sub 1?x}A{sub x}) or (Fe{sub 1?x}B{sub x})Rh (A?=?Cu, Pd; B?=?Ni; 0?FeRh-based systems were determined using isothermal M(H) curves measured in the vicinity of the magnetostructural temperature (T{sub t}). It is found that the FeRh working temperature range (?T{sub FWHM}) may be chemically tuned over a wide temperature range, 100?K???T???400?K. While elemental substitution consistently decreases the magnetic entropy change (?S{sub mag}) of the FeRh-based ternary alloys from that of the parent FeRh compound (?S{sub mag},{sub FeRh}???17?J/kg?K; ?S{sub mag,FeRh-ternary?=}?7–14?J/kg?K at H{sub app}?=?2?T), the net refrigeration capacity (RC), defined as the amount of heat that can be transferred during one magnetic refrigeration cycle, of the modified systems is significantly higher (RC{sub FeRh}???150?J/kg; RC{sub FeRh-ternary?=}?170–210?J/kg at H{sub app}?=?2?T). These results are attributed to stoichiometry-induced changes in the FeRh electronic band structure and beneficial broadening of the magnetostructural transition due to local chemical disorder.

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

    SciTech Connect (OSTI)

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

    1990-09-01

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

  9. Search for supernova-produced 60Fe in a marine sediment

    E-Print Network [OSTI]

    C. Fitoussi; G. M. Raisbeck; K. Knie; G. Korschinek; T. Faestermann; S. Goriely; D. Lunney; M. Poutivtsev; G. Rugel; C. Waelbroeck; A. Wallner

    2007-09-26

    An 60Fe peak in a deep-sea FeMn crust has been interpreted as due to the signature left by the ejecta of a supernova explosion close to the solar system 2.8 +/- 0.4 Myr ago [Knie et al., Phys. Rev. Lett. 93, 171103 (2004)]. To confirm this interpretation with better time resolution and obtain a more direct flux estimate, we measured 60Fe concentrations along a dated marine sediment. We find no 60Fe peak at the expected level from 1.7 to 3.2 Myr ago. However, applying the same chemistry used for the sediment, we confirm the 60Fe signal in the FeMn crust. The cause of the discrepancy is discussed.

  10. The impact of alpha/Fe enhanced stellar evolutionary tracks on the ages of elliptical galaxies

    E-Print Network [OSTI]

    Daniel Thomas; Claudia Maraston

    2003-02-04

    We complement our study of alpha/Fe enhanced stellar population models of Lick absorption indices (Thomas et al. 2003) by comparing two sets of alpha/Fe enhanced models. In both models the impact on Lick indices due to alpha/Fe enhancement is accounted for through a modification of the stellar absorption line-strengths using the response functions of Tripicco & Bell (1995). One set of models, however, uses solar-scaled, the other alpha/Fe enhanced stellar evolutionary tracks. Since the alpha/Fe enhanced tracks are hotter than the solar-scaled ones (Salasnich et al. 2000), the correspondent stellar population models have slightly weaker metallic indices (i.e. Mgb, etc.) and stronger Balmer line indices (Hbeta) (Maraston et al 2003). Here we explore quantitatively the impact of this effect on the alpha/Fe ratios, metallicities and ages that are derived for elliptical galaxies. We find that the modest decrease of the metallic indices Mgb and balance each other, such that fully consistent alpha/Fe ratios are derived for stellar systems using alpha/Fe enhanced models with either solar-scaled or alpha/Fe enhanced stellar tracks. The decrease of the metallic indices and the increase of Hbeta conspire in a way that also consistent metallicities are obtained. The derived ages, instead, are significantly different. The inclusion of alpha/Fe enhanced stellar tracks leads to the derivation of ages as high as 30 Gyr for elliptical galaxies. For the same objects, ages not older than 15 Gyr are obtained, if alpha/Fe enhanced models using solar-scaled tracks are adopted. This may indicate that current stellar evolutionary models overestimate the bluing of stellar evolutionary tracks due to alpha/Fe enhanced chemical mixtures at super-solar metallicities.

  11. Development of an Fe efficiency screening procedure for sorghum based on realistic soil parameters 

    E-Print Network [OSTI]

    Hernandez, Francisco

    1987-01-01

    , are considered to be good indicators of Fe use efficiency in plants, and thus were the basis determining Fe-efficiency of the sorghum cultivars. Rodriguez de Cianzio et al. (1979) reported that visual chlorosis ratings weze highly correlated (r=0. 90...DEVELOPMENT OF AN FE EFFICIENCY SCREENING PROCEDURE FOR SORGHUH BASED ON REAl ISTIC SOIL PARAHETERS A Thesis by FRANCISCO HERNANDEZ Submitted to the Graduate College of Texas ASH University in partial fulfillment of the requirements...

  12. Controlling ferromagnetism of (In,Fe)As semiconductors by electron doping

    SciTech Connect (OSTI)

    Dang Vu, Nguyen; Fukushima, Tetsuya; Katayama-Yoshida, Hiroshi [Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan); Sato, Kazunori [Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2014-02-21

    Based on experimental results, using the Korringa-Kohn-Rostoker coherent potential approximation (KKR-CPA) method and Monte Carlo simulation, we study the mechanism of ferromagnetic behavior of (In,Fe)As. We show that with doped Be atoms occupying in interstitial sites, chemical pair interactions between atoms and magnetic exchange interactions between Fe atoms change due to electron concentration. Therefore, by controlling the doping process, magnetic behavior of (In,Fe)As is controlled and ferromagnetism is observed in this semiconductor.

  13. Improved oxidation sulfidation resistance of Fe-Cr-Ni alloys

    DOE Patents [OSTI]

    Natesan, K.; Baxter, D.J.

    1983-07-26

    High temperature resistance of Fe-Cr-Ni alloy compositions to oxidative and/or sulfidative conditions is provided by the incorporation of about 1 to 8 wt % of Zr or Nb and results in a two-phase composition having an alloy matrix as the first phase and a fine grained intermetallic composition as the second phase. The presence and location of the intermetallic composition between grains of the matrix provides mechanical strength, enhanced surface scale adhesion, and resistance to corrosive attack between grains of the alloy matrix at temperatures of 500 to 1000/sup 0/C.

  14. Oxidation sulfidation resistance of Fe-Cr-Ni alloys

    DOE Patents [OSTI]

    Natesan, Ken (Naperville, IL); Baxter, David J. (Woodridge, IL)

    1984-01-01

    High temperature resistance of Fe-Cr-Ni alloy compositions to oxidative and/or sulfidative conditions is provided by the incorporation of about 1-8 wt. % of Zr or Nb and results in a two-phase composition having an alloy matrix as the first phase and a fine grained intermetallic composition as the second phase. The presence and location of the intermetallic composition between grains of the matrix provides mechanical strength, enhanced surface scale adhesion, and resistance to corrosive attack between grains of the alloy matrix at temperatures of 500.degree.-1000.degree. C.

  15. Active eutectoid decomposition in Zr-3 wt.% Fe

    SciTech Connect (OSTI)

    Kumar, L.; Ramanujan, R.V.; Tewari, R.; Mukhopadhyay, P.; Banerjee, S.

    1999-02-19

    In the work reported here, the microstructural features associated with the active eutectoid decomposition of a near eutectoid alloy (Zr-3 wt.%Fe) on {beta} quenching were examined. The effects of aging after {beta} quenching, and of furnace cooling from the {beta} phase field, on the microstructure of the alloy were also studied. The microstructural characterization was carried out using optical microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM). The room temperature mechanical properties corresponding to some of the microstructures were evaluated by mechanical testing.

  16. Eldorado at Santa Fe, New Mexico: Energy Resources | Open Energy

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTIONRobertsdale, AlabamaETEC GmbH Jump to:Providence,NewInformation at Santa Fe, New Mexico: Energy

  17. Rancho Santa Fe, California: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page onRAPID/Geothermal/Exploration/Colorado <RAPID/Geothermal/WaterEnergy Marketing Corp JumpRam PowerRamsey,San Diego,Fe,

  18. Santa Fe Chamber of Commerce Business Awards Gala

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust, High-ThroughputUpcoming ReleaseSecurity Administration wins twoSanket A.Santa Fe

  19. Santa Fe Community College offers new welding program

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust, High-ThroughputUpcoming ReleaseSecurity Administration wins twoSanket A.Santa FeSanta

  20. AgFe Management Ltd | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to:EAand DaltonSolar EnergyAerodynall Countries | OpenEnergy JumpAgFe

  1. Fe Atomic Data for Non-equilibrium Ionization Plasmas (Conference) |

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing(Journal Article) |production at aSciTech Connect Fe Atomic Data for Non-equilibrium

  2. FE DOCKET NO. 10-161-LNG | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:FinancingPetroleum12, 2015Executive Order14, 2011 CX-006821: CategoricalJuly 8, 20100-161-LNG FE

  3. FE Implementation of the Recovery Act | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submitKansasCommunitiesofExtrans - Permeation Measurement2 0 thFATIGUEFederalBlogFE

  4. SF 6432-FE Fixed Price Contracts Outside the US

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservation of Fe(II) byMultidayAlumni > The EnergyRyanPhysics LabSAP7/31/13 Page 1

  5. Magnetization, magnetic susceptibility, effective magnetic moment of Fe{sup 3+} ions in Bi{sub 25}FeO{sub 39} ferrite

    SciTech Connect (OSTI)

    Zatsiupa, A.A., E-mail: zatsiupa@mail.ru [Belarussian State Technological University, 220030 Minsk (Belarus); Bashkirov, L.A. [Belarussian State Technological University, 220030 Minsk (Belarus); Troyanchuk, I.O. [Scientific and Practical Materials Research Centre of the NAS of Belarus, 220072 Minsk (Belarus); Petrov, G.S. [Belarussian State Technological University, 220030 Minsk (Belarus); Galyas, A.I.; Lobanovsky, L.S.; Truhanov, S.V. [Scientific and Practical Materials Research Centre of the NAS of Belarus, 220072 Minsk (Belarus)

    2014-04-01

    Magnetic susceptibility for ferrite Bi{sub 25}FeO{sub 39} is measured at 5–950 K in the magnetic field of 0.86 T. It is shown that Bi{sub 25}FeO{sub 39} is paramagnetic in the temperature range 5?950 K. The saturation magnetization is equal to 5.04?{sub B} per formula unit at 5 K in a magnetic field of 10 T. It is found that at 5?300 K the effective magnetic moment of Fe{sup 3+} ions in Bi{sub 25}FeO{sub 39} is equal to 5.82?{sub B}. - Graphical abstract: The dependence of the magnetization (n, ?{sub B}) on the magnetic field for one formula unit of Bi{sub 25}FeO{sub 39} at 5 K. - Highlights: • Magnetic susceptibility for Bi{sub 25}FeO{sub 39} is measured at 5–950 K in the magnetic field of 0.86 T. • It is shown that Bi{sub 25}FeO{sub 39} is paramagnetic in the temperature range 5?950 K. • The saturation magnetization is equal to 5.04?{sub B} per formula unit at 5 K in a magnetic field of 10 T.

  6. Effect of CoFe insertion in Co{sub 2}MnSi/CoFe/n-GaAs junctions on spin injection properties

    SciTech Connect (OSTI)

    Ebina, Yuya; Akiho, Takafumi; Liu, Hong-xi; Yamamoto, Masafumi; Uemura, Tetsuya, E-mail: uemura@ist.hokudai.ac.jp [Division of Electronics for Informatics, Graduate School of Information Science and Technology, Hokkaido University, Sapporo 060-0814 (Japan)

    2014-04-28

    The CoFe thickness (t{sub CoFe}) dependence of spin injection efficiency was investigated for Co{sub 2}MnSi/CoFe/n-GaAs junctions. The ?V{sub NL}/I value, which is a measure of spin injection efficiency, strongly depended on t{sub CoFe}, where ?V{sub NL} is the amplitude of a nonlocal spin-valve signal, and I is an injection current. Importantly, the maximum value of ?V{sub NL}/I for a Co{sub 2}MnSi/CoFe/n-GaAs junction was one order of magnitude higher than that for a CoFe/n-GaAs junction, indicating that a Co{sub 2}MnSi electrode works as a highly polarized spin source. No clear spin signal, on the other hand, was observed for a Co{sub 2}MnSi/n-GaAs junction due to diffusion of Mn atoms into the GaAs channel. Secondary ion mass spectrometry analysis indicated that the CoFe insertion effectively suppressed the diffusion of Mn into GaAs, resulting in improved spin injection properties compared with those for a Co{sub 2}MnSi/n-GaAs junction.

  7. Structural, thermodynamic, mechanical, and magnetic properties of FeW system

    SciTech Connect (OSTI)

    Ren, Q. Q.; Fan, J. L.; Han, Y.; Gong, H. R., E-mail: gonghr@csu.edu.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China)

    2014-09-07

    The Fe-W system is systematically investigated through a combined use of first-principles calculation, cluster expansion, special quasirandom structures, and experiments. It is revealed that the ferromagnetic state of BCC Fe-W solid solution has lower heat of formation than its nonmagnetic state within the entire composition range, and intermetallic ?-Fe{sub 2}W and ?-Fe{sub 7}W{sub 6} phases are energetically favorable with negative heats of formation. Calculations also show that the Fe-W solid solution has much lower coefficient of thermal expansion than its mechanical mixture, and that the descending sequence of temperature-dependent elastic moduli of each Fe-W solid solution is E?>?G?>?B. Moreover, magnetic state should have an important effect on mechanical properties of Fe-W phases, and electronic structures can provide a deeper understanding of various properties of Fe-W. The derived results agree well with experimental observations, and can clarify two experimental controversies regarding structural stability and magnetic property of Fe-W phases in the literature.

  8. Electrochemical performance of Sol-Gel synthesized LiFePO4 in lithium batteries

    E-Print Network [OSTI]

    Hu, Yaoqin; Doeff, Marca M.; Kostecki, Robert; Finones, Rita

    2003-01-01

    LiFePO 4 in Lithium Batteries Yaoqin Hu,* Marca M. Doeff,*material in lithium ion batteries based on environmental and

  9. On the Role of Metal Contaminants in Catalyses with FeCl

    E-Print Network [OSTI]

    Bolm, Carsten

    Warning: Catalyzed N-, O-, and C-arylation reactions ascribed to FeCl3 can instead result from catalysis by trace quantities of copper salts.

  10. Magnetism of NiMn2O4-Fe3O4 spinel interfaces

    E-Print Network [OSTI]

    Nelson-Cheeseman, B. B.

    2007-01-01

    material to be used in spintronic applications. It has beenstudies of Fe 3 O 4 in spintronic heterostructures, however,these heterostructures for spintronic applications. In this

  11. 4-20-2010_FE_Final Testimony_Markowsky.pdf

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

    the public. The FE Clean Coal Research Program - administered by the Office of Clean Coal and implemented by the National Energy Technology Laboratory - supports DOE's overall...

  12. Temperature Dependent Magnon-Phonon Coupling in bcc Fe from Theory and Experiment

    E-Print Network [OSTI]

    Tai, Yu-Chong

    - actions in bcc Fe. Parameter-free electronic structure calculations like den- sity functional theory (DFT moments (DLM) molecular dynamics [1], magnetic empirical poten- tials [2

  13. Magnetic Interaction Reversal In Watermelon Nanostructured Cr-doped Fe Nanoclusters

    SciTech Connect (OSTI)

    Kaur, Maninder; Dai, Qilin; Bowden, Mark E.; Engelhard, Mark H.; Wu, Yaqiao; Tang, Jinke; Qiang, You

    2013-11-11

    Cr-doped core-shell Fe/Fe-oxide nanoclusters (NCs) were synthesized at varied atomic percentages of Cr from 0 at. % to 8 at. %. The low concentrations of Cr (<10 at. %) were selected in order to inhibit the complete conversion of the Fe-oxide shell to Cr2O3 and the Fe core to FeCr alloy. The magnetic interaction in Fe/Fe-oxide NCs (rv25 nm) can be controlled by antiferromagnetic Cr-dopant. We report the origin of r-FeCr phase at very low Cr concentration (2 at. %) unlike in previous studies, and the interaction reversal from dipolar to exchange interaction in watermelon-like Cr-doped core-shell NCs. The giant magnetoresistance (GMR) effect,1,2 where an antiferromagnetic (AFM) exchange coupling exists between two ferromagnetic (FM) layers separated by a certain type of magnetic or non-magnetic spacer,3 has significant potential for application in the magnetic recording industry. Soon after the discovery of the GMR, the magnetic properties of multilayer systems (FeCr) became a subject of intensive study. The application of bulk iron-chromium (Fe-Cr) alloys has been of great interest, as these alloys exhibit favorable prop- erties including corrosion resistance, high strength, hardness, low oxidation rate, and strength retention at elevated temper- ature. However, the structural and magnetic properties of Cr-doped Fe nanoclusters (NCs) have not been investigated in-depth. Of all NCs, Fe-based clusters have unique magnetic properties as well as favorable catalytic characteristics in reactivity, selectivity, and durability.4 The incorporation of dopant of varied type and concentration in Fe can modify its chemical ordering, thereby optimizing its electrical, optical, and magnetic properties and opening up many new applications. The substitution of an Fe atom (1.24 A? ) by a Cr atom (1.25 A? ) can easily modify the magnetic properties, since (i) the curie temperature (Tc ) of Fe is 1043 K, while Cr is an itinerant AFM with a bulk Neel temperature TN =311 K, and (ii) Fe and Cr share the same crystal structure (bcc) with only 0.5% difference between their lattice constants.

  14. Nanostructure evolution in joining of Al and Fe nanoparticles with femtosecond laser irradiation

    SciTech Connect (OSTI)

    Jiao, Z.; Huang, H.; Zhou, Y. E-mail: nzhou@uwaterloo.ca; Liu, L.; Hu, A.; Duley, W.; He, P. E-mail: nzhou@uwaterloo.ca

    2014-04-07

    The joining of Al-Fe nanoparticles (NPs) by femtosecond (fs) laser irradiation is reported in this paper. Fe and Al NPs were deposited on a carbon film in vacuum via fs laser ablation. Particles were then exposed to multiple fs laser pulses at fluences between 0.5 and 1.3?mJ/cm{sup 2}. Transmission Electron Microscopy (TEM) and Electron Diffraction X-ray observations indicate that Al and Fe NPs bond to each other under these conditions. For comparison, bonding of Al to Al and Fe to Fe NPs was also investigated. The nanostructure, as observed using TEM, showed that individual Al NPs were monocrystalline while individual Fe NPs were polycrystalline prior to joining and that these structures are retained after the formation of Al-Al and Fe-Fe NPs. Al-Fe NPs produced by fs laser joining exhibited a mixed amorphous and crystalline phase at the interface. Bonding is suggested to originate from intermixing within a region of high field intensity between particles.

  15. Low temperature thermoelectric properties of Co0.9Fe0.1Sb3-based...

    Office of Scientific and Technical Information (OSTI)

    The nanoscale FeSbsub 2 precipitates are well dispersed in the skutterudite matrix and reduce the lattice thermal conductivity due to additional phonon scattering from...

  16. CORROSION OF Fe-10Al-Cr ALLOYS BY COAL CHAR

    E-Print Network [OSTI]

    Gordon, B.A.

    2011-01-01

    off-gas from a typical gasifier contains large percentagesIOAl-Cr alloys at coal-gasifier This FeS and CaS0 operating

  17. Project Management Plan - Small Producers Program

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

    RPSEA Final Report 09123.11.Final Enhanced Oil Recovery from the Bakken Shale using Surfactant Imbibition Coupled with Gravity Drainage 09123-09 Dongmei Wang Petroleum Engineering...

  18. NETL F 451.1/1-1, Categorical Exclusion Designation Form

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

    RPSEA Sugarland, TX CSI Technologies, LLC. Possible Pad locations covered by this CX Form include Conway, Faulkner, Cleburne, Pope, White, and Van Buren counties, Arkansas...

  19. NETL F 451.1/1-1, Categorical Exclusion Designation Form

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

    12121-6301-03 RPSEA Sugar Land, TX Clearview Subsea, Houston, Texas FESCNGO Bill Fincham Subsea Produced Water Sensor Development Develop and design subsea water quality sensor...

  20. Thermodynamic Modeling and Experimental Study of the Fe-Cr-Zr System

    SciTech Connect (OSTI)

    Yang, Ying; Tan, Lizhen; Bei, Hongbin; Busby, Jeremy T

    2013-01-01

    Wide applications of zircaloys, stainless steels and their interactions in nuclear reactors require the knowledge on phase stability and thermodynamic property of the Fe-Cr-Zr system. This knowledge is also important to develop new Zr-contained Fe-Cr ferritic steels. This work aims at developing thermodynamic models for describing phase stability and thermodynamic property of the Fe-Cr-Zr system using the Calphad approach coupled with experimental study. Thermodynamic descriptions of the Fe-Cr and Cr-Zr systems were either directly adopted or slightly modified from literature. The Fe-Zr system has been remodeled to accommodate recent ab-initio calculation of formation enthalpies of various Fe-Zr compounds. Reliable ternary experimental data and thermodynamic models were mainly available in the Zr-rich region. Therefore, selected ternary alloys located in the vicinity of the eutectic valley of (Fe,Cr,Zr) and (Fe,Cr)2Zr laves phase in the Fe-rich region have been experimentally investigated in this study. Microstructure has been examined by using scanning electron microscope, energy-dispersive Xray spectroscopy and X-ray diffraction. These experimental results, along with the literature data were then used to develop thermodynamic models for phases in the Fe-Cr-Zr system. Calculated phase equilibria and thermodynamic properties of the ternary system yield satisfactory agreements with available experimental data, which gives the confidence to use these models as building blocks for developing a Zr, Fe and Cr contained multicomponent thermodynamic database for broader applications in nuclear reactors.

  1. Effects of boron composition on tunneling magnetoresistance ratio and microstructure of CoFeB/MgO/CoFeB pseudo-spin-valve magnetic tunnel junctions

    SciTech Connect (OSTI)

    Kodzuka, M.; Ohkubo, T.; Hono, K.; Ikeda, S.; Ohno, H.; Gan, H. D.

    2012-02-15

    The effect of B concentration on the tunneling magnetoresistance (TMR) of (Co{sub 25}Fe{sub 75}){sub 100-x}B{sub x}/MgO/(Co{sub 25}Fe{sub 75}){sub 100-x}B{sub x} (x = 22 and 33) pseudo-spin-valve (P-SV) magnetic tunnel junctions (MTJs) was investigated. The TMR ratios for optimally annealed MTJs with x = 22 and 33 were 340% and 170%, respectively, at room temperature. High resolution transmission electron microscopy (HRTEM) observation showed a weaker (001) texture in the MgO barrier in the MTJ with x = 33. The bottom electrode was not fully crystallized even with a considerable amount of B in the (Co{sub 25}Fe{sub 75}){sub 67}B{sub 33}, while good epitaxy was observed between (001) textured MgO and (Co{sub 25}Fe{sub 75}){sub 78}B{sub 22} electrodes.

  2. Itinerant electrons, local moments, and magnetic correlations in the pnictide superconductors CeFeAsO??xFxand Sr(Fe??xCox)?As?

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

    Vilmercati, Paolo; Fedorov, Alexei; Bondino, Federica; Offi, Francesco; Panaccione, Giancarlo; Lacovig, Paolo; Simonelli, Laura; McGuire, Michael A.; Sefat, Athena S. M.; Mandrus, David; et al

    2012-06-15

    A direct and element-specific measurement of the local Fe spin moment has been provided by analyzing the Fe 3s core level photoemission spectra in the parent and optimally doped CeFeAsO??xFx (x = 0, 0.11) and Sr(Fe??xCox)2As2 (x = 0, 0.10) pnictides. The rapid time scales of the photoemission process allowed the detection of large local spin moments fluctuating on a 10?¹? s time scale in the paramagnetic, antiferromagnetic, and superconducting phases, indicative of the occurrence of ubiquitous strong Hund's magnetic correlations. The magnitude of the spin moment is found to vary significantly among different families, 1.3?B in CeFeAsO and 2.1?Bmore »in SrFe?As?. Surprisingly, the spin moment is found to decrease considerably in the optimally doped samples, 0.9?B in CeFeAsO?.??F?.?? and 1.3?B in Sr(Fe?.?Co?.?)?As?. The strong variation of the spin moment against doping and material type indicates that the spin moments and the motion of itinerant electrons are influenced reciprocally in a self-consistent fashion, reflecting the strong competition between the antiferromagnetic superexchange interaction among the spin moments and the kinetic energy gain of the itinerant electrons in the presence of a strong Hund's coupling. By describing the evolution of the magnetic correlations concomitant with the appearance of superconductivity, these results constitute a fundamental step toward attaining a correct description of the microscopic mechanisms shaping the electronic properties in the pnictides, including magnetism and high-temperature superconductivity.« less

  3. Phase formation in ZrFe multilayers: Effect of irradiation A. T. Motta

    E-Print Network [OSTI]

    Motta, Arthur T.

    Phase formation in Zr­Fe multilayers: Effect of irradiation A. T. Motta The Pennsylvania State Science Division, Argonne National Laboratory, Argonne, Illinois 60403 M. E. Bru¨ckmann, S. R. Teixeira a detailed in situ study of phase formation in Zr­Fe metallic multilayers using irradiation and thermal

  4. Carbon-Supported bimetallic Pd-Fe catalysts for vapor-phase hydrodeoxygenation of guaiacol

    SciTech Connect (OSTI)

    Sun, Junming; Karim, Ayman M.; Zhang, He; Kovarik, Libor; Li, Xiaohong S.; Hensley, Alyssa; McEwen, Jean-Sabin; Wang, Yong

    2013-10-01

    Abstract Carbon supported metal catalysts (Cu/C, Fe/C, Pd/C, Pt/C, PdFe/C and Ru/C) have been prepared, characterized and tested for vapor-phase hydrodeoxygenation (HDO) of guaiacol (GUA) at atmospheric pressure. Phenol was the major intermediate on all catalysts. Over the noble metal catalysts saturation of the aromatic ring was the major pathway observed at low temperature (250 °C), forming predominantly cyclohexanone and cyclohexanol. Substantial ring opening reaction was observed on Pt/C and Ru/C at higher reaction temperatures (e.g., 350 °C). Base metal catalysts, especially Fe/C, were found to exhibit high HDO activity without ring-saturation or ring-opening with the main products being benzene, phenol along with small amounts of cresol, toluene and trimethylbenzene (TMB). A substantial enhancement in HDO activity was observed on the PdFe/C catalysts. Compared with Fe/C, the yield to oxygen-free aromatic products (i.e., benzene/toluene/TMB) on PdFe/C increased by a factor of four at 350 °C, and by approximately a factor of two (83.2% versus 43.3%) at 450 °C. The enhanced activity of PdFe/C is attributed to the formation of PdFe alloy as evidenced by STEM, EDS and TPR.

  5. Mixed-Valent Fe Films ('Schwimmeisen') on the Surface of Reduced Ephemeral Pools

    SciTech Connect (OSTI)

    Grathoff, Georg H.; Baham, John E.; Easterly, Heather R.; Gassman, Paul L.; Hugo, Rick C.

    2007-12-01

    Floating, mixed-valent Fe films have been observed worldwide in wetlands, ferrous iron rich seeps, and in seasonally reduced soils, but are usually misidentified as oil or biofilms. Little characterization or explanation to their formation has taken place. Along the Oregon coast such films were found on ephemeral pools where Fe(II) rich groundwater (~ 100 ?M Fe) discharged at the base of Pleistocene sand dunes. Fe(II) oxidized to Fe(III) at the air-water interface to form ~ 100 to 300nm thick films. Analyses indicated that the films contained both Fe(III) and Fe(II) in a ratio of 3:1. Si was the other main cation, OH was the main anion and some C was identified as well. The film morphology was flat, under optical and electron microscopy with some attached floccules having a stringlike morphology. Energy filtered electron diffraction patterns (EFED) showed three diffraction rings at 4.5, 2.6, and 1.4 Å in some places and 2 rings (2.6 and 1.4 Å) in others. Upon further oxidation the films became 2-line ferrihydrite. We are proposing the name „Schwimmeisen“ for the floating, mixed-valent Fe film.

  6. Water adsorption on alpha-Fe2O3(0001) at near ambient conditions

    E-Print Network [OSTI]

    Yamamoto, Susumu

    2010-01-01

    Journal of Physical Chemistry Water adsorption on at n e a rR U N N I N G H E A D : Water adsorption on a-Fe O (0001) *investigated hydroxylation and water adsorption on a-Fe O (

  7. Combined Microbial-Fe(0) Treatment Systems 1 1058-8337/00/$.50

    E-Print Network [OSTI]

    Alvarez, Pedro J.

    Combined Microbial-Fe(0) Treatment Systems 1 1058-8337/00/$.50 © 2000 by Battelle Memorial Institute Bioremediation Journal 4(1):0­0 (2000) Combined Microbial-Fe(0) Treatment System to Remove Nitrate this energy source to autotrophic denitrifying bacteria. Research with hydrogenotrophic, anaerobic bac- teria

  8. Probe Mössbauer spectroscopy of mechanical alloying in binary Cr?{sup 57}Fe(1 at%) system

    SciTech Connect (OSTI)

    Elsukov, Evgeny P. Kolodkin, Denis A. Ul'yanov, Alexander L. Porsev, Vitaly E.

    2014-10-27

    Solid state reactions during mechanical alloying (MA) in a binary mixture of powdered Cr and {sup 57}Fe in atomic ratio of 99:1 have been studied using {sup 57}Fe Mössbauer spectroscopy, X-ray diffraction and Auger spectrometry. The proposed model of MA includes formation of Cr(Fe){sub x}O{sub y} oxides at the contact places of Cr and Fe particles, formation of nanostructure with simultaneous dissolution of the oxides, penetration of Fe atoms along grain boundaries in close-to-boundary distorted zones of interfaces in a substitutional position, formation of the substitutional solid solution of Fe in Cr in the body of grains. It was shown that the increase in the BCC lattice parameter on increasing the milling time is due to the dissolution of oxides and formation of interstitial solid solution of O in Cr. There were established substantial differences in consumption of BCC Fe in a Mg ? Al ? Si ? Cr sequence due to the major role of chemical interaction of Mg(Al,Si,Cr) with Fe.

  9. Characteristics of Phosphate Adsorption-Desorption Onto Ferrihydrite: Comparison With Well-Crystalline Fe

    E-Print Network [OSTI]

    Sparks, Donald L.

    . Sparks2 Abstract: The adsorption-desorption behavior of phosphate on ferrihydrite, goethite, and hematite for ferrihydrite and goethite, yet more time for hematite; phosphate exchange with Fe-OH2 1/2+ and Fe-OH1/2j goethite (10%) 9 ferrihydrite (8.5%). The lower desorption for ferrihydrite indicates a higher percentage

  10. Short communication Chemically abrupt interface between Ce oxide and Fe films

    E-Print Network [OSTI]

    Kim, Sehun

    of an Fe film followed by deposition of Ce metal. Once a Ce oxide layer is formed on top of Fe, it acts.90.+f; 74.25.jb; 79.60 Ài; 79.60.Dp Keywords: MTJ; Ce oxide layer; XPS Magnetic tunneling junctions (MTJ of the oxide layer, resulting in decreased tunneling magneto- resistance and fluctuations in the local

  11. First-principles study of iron oxyfluorides and lithiation of FeOF

    E-Print Network [OSTI]

    Chevrier, Vincent L.

    First-principles studies of iron oxyfluorides in the FeF[subscript 2] rutile framework (FeO[subscript x]F[subscript 2?x], 0?x?1) are performed using density functional theory (DFT) in the general gradient approximation ...

  12. Building the Santa Fe Artificial Stock Market Blake LeBaron

    E-Print Network [OSTI]

    Tesfatsion, Leigh

    Building the Santa Fe Artificial Stock Market Blake LeBaron Brandeis University June 2002 Abstract This short summary presents an insider's look at the construction of the Santa Fe artificial stock of the directions that researchers have been taking is the use of agent-based financial markets. These "bottom- up

  13. Millimeter-wave spectroscopy of FeF (X 6 i): Rotational analysis

    E-Print Network [OSTI]

    Ziurys, Lucy M.

    , 1, and 2 vibrational levels of 56 FeF, the main isotopic species, and also in the less abundant 54 less abundant isotopes, and, more recently, Fe-bearing mol- ecules, have impacted on the understanding small iron-bearing molecules have actually been studied using this approach. To date, the list

  14. Adhesion of Bacterial Exopolymers to r-FeOOH: Inner-Sphere Complexation of Phosphodiester Groups

    E-Print Network [OSTI]

    Chorover, Jon

    Adhesion of Bacterial Exopolymers to r-FeOOH: Inner-Sphere Complexation of Phosphodiester Groups of polyelectrolytes that mediate biomineralization and bacterial adhesion and stabilize biofilm matrixes in natural-FeOOH) surface, providing an energetically stable bond for further EPS or cell adhesion. 1. Introduction

  15. Soil and Mold Influences on Fe and Zn Concentrations of Sorghum Grain in Mali, West Africa 

    E-Print Network [OSTI]

    Verbree, Cheryl

    2012-10-19

    breeders in Mali are working to increase sorghum grain Fe and Zn concentrations. The objective of this study was to investigate soil and mold influences that affect Fe and Zn uptake and accumulation in sorghum grain. In southern Mali, soils from...

  16. Single-walled carbon nanotube growth from ion implanted Fe catalyst Yongho Choi

    E-Print Network [OSTI]

    Ural, Ant

    the growth of carbon nanotubes. Typically, transition metal nanoparticles, such as nickel Ni , iron FeSingle-walled carbon nanotube growth from ion implanted Fe catalyst Yongho Choi Department-walled carbon nanotubes can be grown by chemical vapor deposition from ion implanted iron catalyst

  17. Precise Measurement of Dimuon Production Cross-Sections in Fe Deep Inelastic Scattering at the Tevatron

    E-Print Network [OSTI]

    Precise Measurement of Dimuon Production Cross-Sections in #23; #22; Fe and #22; #23; #22; Fe Deep statistically precise measurement of neutrino-induced dimuon production cross-sections to date. These measure, USA Version 11.02.00 1 #12; (February 14, 2001) Abstract We present measurements of the semi

  18. Effect of Mo Addition on Structure and Magnetocaloric Effect in c-FeNi Nanocrystals

    E-Print Network [OSTI]

    Laughlin, David E.

    - tion metals have been investigated to replace rare- earth metals for cost reduction. Researchers have comparable to those of rare-earth metals. Recently, Fe-Ni alloys were suggested as economical alterna- tives3 refrigerants without critical rare-earth materials. Key words: Nanostructured FeNi, magnetocaloric effect

  19. Grain growth in ZrFe thin films during in situ ion irradiation in a TEM

    E-Print Network [OSTI]

    Motta, Arthur T.

    Grain growth in Zr­Fe thin films during in situ ion irradiation in a TEM D. Kaoumi a,*, A.T. Motta Laboratory, Argonne, IL 060493, USA Available online 2 November 2005 Abstract In situ ion-beam irradiation was used to study irradiation induced grain growth in co-sputter-deposited Zr/xFe (0% 6 x 6 4

  20. Magnetic and structural behavior of FeCo/Cu multilayers submitted to Kr irradiation

    E-Print Network [OSTI]

    Penkov, Julian Geshev

    Magnetic and structural behavior of FeCo/Cu multilayers submitted to Kr irradiation I.L. Graff Cedex, France Available online 19 January 2007 Abstract We have studied the effects of ion irradiation a phase transformation of FeCo alloy from bcc for the as-deposited sample to fcc after irradiation

  1. Quantum chemical study of the Fe(III)-desferrioxamine B siderophore complex--Electronic structure,

    E-Print Network [OSTI]

    Sparks, Donald L.

    . D. (2001) Fractionation of Fe isotopes by soil microbes and organic acids. Geology 29, 535 complexation with small organic acids (e.g., oxalate), subsequently sequestered by DFO-B in solution and Fitzwater, 1988). Siderophores, an important class of organic acids with large complexation constants for Fe

  2. Fe3O4 magnetic nanoparticles synthesis from tailings by ultrasonic chemical co-precipitation

    E-Print Network [OSTI]

    Volinsky, Alex A.

    Fe3O4 magnetic nanoparticles synthesis from tailings by ultrasonic chemical co-precipitation Shen online xxxx Keywords: Fe3O4 nanoparticles Ultrasonic-assisted chemical co-precipitation Surfaces Magnetic-assisted chemical co- precipitation utilizing high purity iron separated from iron ore tailings by acidic leaching

  3. Tuning exchange bias in Fe/?-Fe{sub 2}O{sub 3} core-shell nanoparticles: Impacts of interface and surface spins

    SciTech Connect (OSTI)

    Khurshid, Hafsa E-mail: phanm@usf.edu Phan, Manh-Huong E-mail: phanm@usf.edu Mukherjee, Pritish; Srikanth, Hariharan E-mail: phanm@usf.edu

    2014-02-17

    A comparative study has been performed of the exchange bias (EB) effect in Fe/?-Fe{sub 2}O{sub 3} core-shell nanoparticles with the same thickness of the ?-Fe{sub 2}O{sub 3} shell (?2?nm) and the diameter of the Fe core varying from 4?nm to 11?nm. Transmission electron microscopy (TEM) and high-resolution TEM confirmed the high quality of the core-shell nanostructures. A systematic analysis of magnetization versus magnetic field measurements under zero-field-cooled and field-cooled regimes using the Meiklejohn-Bean model and deconvoluting superparamagnetic and paramagnetic contribution to the total magnetic moment Langevin function shows that there exists a critical particle size (?10?nm), above which the spins at the interface between Fe and ?-Fe{sub 2}O{sub 3} contribute primarily to the EB, but below which the surface spin effect is dominant. Our finding yields deeper insight into the collective contributions of interface and surface spins to the EB in core-shell nanoparticle systems, knowledge of which is the key to manipulating EB in magnetic nanostructures for spintronics applications.

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

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

    Popovi?, Z. V.; Š?epanovi?, M.; Lazarevi?, N.; Opa?i?, M.; Radonji?, M. M.; Tanaskovi?, D.; Lei, Hechang; Petrovic, C.

    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 themore »lattice 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

  5. 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 themore »lattice 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

  6. A New Redox Flow Battery Using Fe/V Redox Couples in Chloride Supporting Electrolyte

    SciTech Connect (OSTI)

    Wang, Wei; Kim, Soowhan; Chen, Baowei; Nie, Zimin; Zhang, Jianlu; Xia, Guanguang; Li, Liyu; Yang, Zhenguo

    2011-08-22

    A new redox flow battery using Fe2+/Fe3+ and V2+/V3+ redox couples in chloride supporting electrolyte was proposed and investigated for potential stationary energy storage applications. The Fe/V redox flow cell using mixed reactant solutions operated within a voltage window of 0.5-1.35 V with a nearly 100% utilization ratio and demonstrated stable cycling with energy efficiency around 80% at room temperature. Compared with Fe/Cr redox flow battery operating at an elevated temperature of 65 C, the necessity of external heat management is eliminated. Similar performance was also achieved using low-cost hydrocarbon-based ion exchange membranes, which allow for further cost reduction. The improved room temperature electrochemical performance makes the Fe/V redox flow battery a promising option as stationary energy storage device to enable renewable integration and stabilization of electrical grid.

  7. Thermal plasma synthesis of Fe{sub 1?x}Ni{sub x} alloy nanoparticles

    SciTech Connect (OSTI)

    Raut, Suyog A.; Kanhe, Nilesh S.; Bhoraskar, S. V.; Mathe, V. L.; Das, A. K.

    2014-04-24

    Fe-Ni alloy nanoparticles are of great interest because of diverse practical applications in the fields such as magnetic fluids, high density recording media, catalysis and medicine. We report the synthesis of Fe-Ni nanoparticles via thermal plasma route. Thermal plasma assisted synthesis is a high temperature process and gives high yields of production. Here, we have used direct arc thermal plasma plume of 6kw as a source of energy at operating pressure 500 Torr. The mixture of Fe-Ni powder in required proportion (Fe{sub 1?x}Ni{sub x}; x=0.30, 0.32, 0.34, 0.36, 0.38 and 0.40) was made to evaporate simultaneously from the graphite anode in thermal plasma reactor to form Fe-Ni bimetallic nanoparticles. The as synthesized particles were characterized by X-Ray Diffraction (XRD), Thermo-Gravimetric Analysis/Differential Scanning Calorimtry (TGA/DSC)

  8. Electrochemical sensing behaviour of Ni doped Fe{sub 3}O{sub 4} nanoparticles

    SciTech Connect (OSTI)

    Suresh, R.; Giribabu, K.; Manigandan, R.; Narayanan, V., E-mail: vnnara@yahoo.co.in [Department of Inorganic Chemistry, University of Madras, Guindy Campus, Chennai 600 025 (India); Vijayalakshmi, L. [Annai Veilankanni's College for Women (Arts and Science), Saidapet, Chennai 600015 (India); Stephen, A. [Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai 600 025 (India)

    2014-01-28

    Ni doped Fe{sub 3}O{sub 4} nanoparticles were synthesized by simple hydrothermal method. The prepared nanomaterials were characterized by X-ray diffraction analysis, DRS-UV-Visible spectroscopy and field emission scanning electron microscopy. The XRD confirms the phase purity of the synthesized Ni doped Fe{sub 3}O{sub 4} nanoparticles. The optical property of Ni doped Fe{sub 3}O{sub 4} nanoparticles were studied by DRS UV-Visible analysis. The electrochemical sensing property of pure and Ni doped Fe{sub 3}O{sub 4} nanoparticles were examined using uric acid as an analyte. The obtained results indicated that the Ni doped Fe{sub 3}O{sub 4} nanoparticles exhibited higher electrocatalytic activity towards uric acid.

  9. Intrinsic magnetic properties of hexagonal LuFeO{sub 3} and the effects of nonstoichiometry

    SciTech Connect (OSTI)

    Moyer, Jarrett A. E-mail: schlom@cornell.edu; Schiffer, Peter; Misra, Rajiv; Mundy, Julia A.; Brooks, Charles M.; Heron, John T.; Muller, David A.; Schlom, Darrell G. E-mail: schlom@cornell.edu

    2014-01-01

    We used oxide molecular-beam epitaxy in a composition-spread geometry to deposit hexagonal LuFeO{sub 3} (h-LuFeO{sub 3}) thin films with a monotonic variation in the Lu/Fe cation ratio, creating a mosaic of samples that ranged from iron rich to lutetium rich. We characterized the effects of composition variation with x-ray diffraction, atomic force microscopy, scanning transmission electron microscopy, and superconducting quantum interference device magnetometry. After identifying growth conditions leading to stoichiometric film growth, an additional sample was grown with a rotating sample stage. From this stoichiometric sample, we determined stoichiometric h-LuFeO{sub 3} to have a T{sub N} = 147 K and M{sub s} = 0.018 ?{sub B}/Fe.

  10. Level density of $^{56}$Fe and low-energy enhancement of $?$-strength function

    E-Print Network [OSTI]

    A. V. Voinov; S. M. Grimes; U. Agvaanluvsan; E. Algin; T. Belgya; C. R. Brune; M. Guttormsen; M. J. Hornish; T. Massey; G. E. Mitchell; J. Rekstad; A. Schiller; S. Siem

    2006-04-06

    The $^{55}$Mn$(d,n)^{56}$Fe differential cross section is measured at $E_d=7$ MeV\\@. The $^{56}$Fe level density obtained from neutron evaporation spectra is compared to the level density extracted from the $^{57}$Fe$(^3$He,$\\alpha\\gamma)^{56}$Fe reaction by the Oslo-type technique. Good agreement is found between the level densities determined by the two methods. With the level density function obtained from the neutron evaporation spectra, the $^{56}$Fe $\\gamma$-strength function is also determined from the first-generation $\\gamma$ matrix of the Oslo experiment. The good agreement between the past and present results for the $\\gamma$-strength function supports the validity of both methods and is consistent with the low-energy enhancement of the $\\gamma$ strength below $\\sim 4$ MeV first discovered by the Oslo method in iron and molybdenum isotopes.

  11. Comparison of LiFePO4 from different sources

    SciTech Connect (OSTI)

    Striebel, Kathryn; Shim, Joongpyo; Srinivasan, Venkat; Newman, John

    2003-11-25

    The lithium iron phosphate chemistry is plagued by the poor conductivity and slow lithium diffusion in the solid phase. In order to alleviate these problems, various research groups have adopted different strategies including decreasing the particle sizes, increasing the carbon content, and adding dopants. In this study we obtained LiFePO4 electrodes from six different sources and used a combined model-experimental approach to compare the performance. Samples ranged from one with no carbon coating to one with 15 percent coating. In addition, particle sizes varied by as much as a order of magnitude between samples. The study detailed in this manuscript allows us to provide insight into the relative importance of the conductivity of the samples compared to the particle size, the impact of dopant on performance and ideas for making materials in order to maximize the power capability of this chemistry.

  12. Comparison of LiFePO4 from different sources

    SciTech Connect (OSTI)

    Striebel, Kathryn; Shim, Joongpyo; Srinivasan, Venkat; Newman, John

    2004-06-21

    The lithium iron phosphate chemistry is plagued by the poor conductivity and slow diffusion in the solid phase. In order to alleviate these problems, various research groups have adopted different strategies including decreasing the particle sizes, increasing the carbon content, and adding dopants. In this study, we obtained LiFePO{sub 4} powders and/or electrodes from six different sources and used a combined model-experimental approach to compare the performance. Samples ranged from 0.4% to 15% ''in-situ'' carbon. In addition, particle sizes varied by as much as an order of magnitude between samples. The study detailed in this manuscript allows us to provide insight into the relative importance of the conductivity of the samples compared to the particle size, the impact of having a distribution in particle sizes, and ideas for making materials in order to maximize the power capability of this chemistry.

  13. Resolving the stellar sources of isotopically rare presolar silicate grains through Mg and Fe isotopic analyses

    SciTech Connect (OSTI)

    Nguyen, Ann N.; Messenger, Scott, E-mail: lan-anh.n.nguyen@nasa.gov [Robert M. Walker Laboratory for Space Science, Astromaterials Research and Exploration Science Directorate, NASA Johnson Space Center, Houston, TX 77058 (United States)

    2014-04-01

    We conducted multi-element isotopic analyses of 11 presolar silicate grains from the Acfer 094 meteorite having unusual O isotopic compositions. Eight grains are {sup 18}O-rich, one is {sup 16}O-rich, and two are extremely {sup 17}O-rich. We constrained the grains' stellar sources by measuring their Si and Mg isotopic ratios, and also the {sup 54}Fe/{sup 56}Fe and {sup 57}Fe/{sup 56}Fe ratios for five grains. The Mg and Fe isotopic measurements were conducted after surrounding matrix grains were removed for more accurate ratios. Most of the {sup 18}O-rich silicates had anomalous Mg isotopic ratios, and their combined isotopic constraints are consistent with origins in low-mass Type II supernovae (SNe II) rather than high-metallicity stars. The isotopic ratios of the {sup 16}O-rich silicate are also consistent with an SN origin. Mixing small amounts of interior stellar material with the stellar envelope replicated all measured isotopic ratios except for {sup 29}Si/{sup 28}Si and {sup 54}Fe/{sup 56}Fe in some grains. The {sup 29}Si/{sup 28}Si ratios of all SN-derived grains are matched by doubling the {sup 29}Si yield in the Ne- and Si-burning zones. The {sup 54}Fe/{sup 56}Fe ratios of the grains imply elemental fractionation in the Si/S zone, or introduction of isotopically solar Fe by secondary processing. The two highly {sup 17}O-rich silicates exhibited significant {sup 25}Mg and/or {sup 26}Mg enrichments and their isotopic ratios are best explained by strong dilution of 1.15 M {sub ?} CO nova matter. We estimate that ?12% and 1% of presolar silicates have SN and nova origins, respectively, similar to presolar SiC and oxides. This implies that asymptotic giant branch stars are the dominant dust producers in the galaxy.

  14. Fe VII lines in the spectrum of RR Telescopii

    E-Print Network [OSTI]

    P. R. Young; K. A. Berrington; A. Lobel

    2004-12-07

    Thirteen transitions within the ground 3d^2 configuration of Fe VII are identified in ultraviolet and optical spectra of the symbiotic star RR Telescopii obtained with the STIS instrument of the Hubble Space Telescope. The line fluxes are compared with theoretical data computed with the recent atomic data of K.A. Berrington et al., and high resolution optical spectra from VLT/UVES are used to identify blends. Seven branching ratios are measured, with three in good agreement with theory and one affected by blending. The lambda5277/lambda4943 branching ratio is discrepant by > 3 sigma, indicating errors in the atomic data for the lambda5277 line. A least-squares minimization scheme is used to simultaneously derive the temperature, T, and density, N_e, of the RR Tel nebula, and the interstellar extinction, E(B-V), towards RR Tel from the complete set of emission lines. The derived values are: log T/K = 4.50 +/- 0.23, log N_e/cm^-3=7.25 +/- 0.05, and E(B-V)<0.27. The extinction is not well-constrained by the Fe VII lines, but is consistent with the more accurate value E(B-V)=0.109^{+0.052}_{-0.059} derived here from the Ne V lambda2974/lambda1574 ratio in the STIS spectrum. Large differences between the K.A. Berrington et al. electron excitation data and the earlier F.P. Keenan & P.H. Norrington data-set are demonstrated, and the latter is shown to give worse agreement with observations.

  15. SPIN DENSITY OF THE CANTED MOMENT IN 03B1-Fe2O3 (1) By S. J. PICKART,

    E-Print Network [OSTI]

    Boyer, Edmond

    avec des neutrons polarisés. On trouve que cette densité diffère de celle de l'ion Fe3+. Abstract. 2014 neutrons and found to differ from that of the Fe3+ ion. LE JOURNAL DE PHYSIQUE TOME 25, MAI 1964, as established by the original neutron diffraction measurements [3], consists of the Fe3 ~ spins in each (111

  16. Nanoscale LiFePO4 and Li4Ti5O12 for High Rate Li-ion Batteries

    E-Print Network [OSTI]

    Jaiswal, A.

    2010-01-01

    a LiFePO 4 /Li 4 Ti 5 O 12 full-cell at several different4 /Li 4 Ti 5 O 12 coin full-cell. Figure 1. 0.2 µ m (a) (b)in LiFePO 4 /Li 4 Ti 5 O 12 full cells. Nano-LiFePO 4 showed

  17. Model for the Magnetic Order and Pairing Channels in Fe Pnictide Superconductors M. Daghofer,1,2

    E-Print Network [OSTI]

    Tennessee, University of

    Model for the Magnetic Order and Pairing Channels in Fe Pnictide Superconductors M. Daghofer,1,2 A 2008; published 4 December 2008) A two-orbital model for Fe-pnictide superconductors is investigated of superconductiv- ity in the layered rare-earth oxypnictides compounds LnO1ÀxFxFeAs (Ln ¼ La, Pr, Ce, Sm) has

  18. Potential Role of Nitrite for Abiotic Fe(II) Oxidation and Cell Encrustation during Nitrate Reduction by Denitrifying Bacteria

    E-Print Network [OSTI]

    Konhauser, Kurt

    Reduction by Denitrifying Bacteria Nicole Klueglein,a Fabian Zeitvogel,b York-Dieter Stierhof,c Matthias and microoxic conditions. While most of the mix- otrophic nitrate-reducing Fe(II)-oxidizing bacteria become assemblage of Fe(II)-oxidizing bacteria in nature and compli- cates our ability to delineate microbial Fe

  19. Irradiation-Enhanced Second-Phase Precipitation in Zr-Fe Nanocrystalline Thin Films , A. T. Motta1

    E-Print Network [OSTI]

    Motta, Arthur T.

    Irradiation-Enhanced Second-Phase Precipitation in Zr-Fe Nanocrystalline Thin Films D. Kaoumi1 , A with Fe. Heat treatment in the absence of irradiation was observed to cause precipitation of the Zr2Fe in the presence of ion irradiation. Samples were irradiated in-situ at the Intermediate Voltage Electron

  20. The importance of Fe surface states for spintronic devices based on magnetic tunnel junctions

    SciTech Connect (OSTI)

    Chantis, Athanasios N

    2008-01-01

    In this article we give a review of our recent theoretical studies of the influence of Fe(001) surface (interface) states on spin-polarized electron transport across magnetic tunnel junctions with Fe electrodes. We show that minority-spin surface (interface) states are responsible for at least two effects which are important for spin electronics. First, they can produce a sizable tunneling anisotropic magnetoresistance in magnetic tunnel junctions with a single Fe electrode. The effect is driven by a Rashba shift of the resonant surface band when the magnetization changes direction. This can introduce a new class of spintronic devices, namely, tunneling magnetoresistance junctions with a single ferromagnetic electrode. Second, in Fe/GaAs(001) magnetic tunnel junctions minority-spin interface states produce a strong dependence of the tunneling current spin polarization on applied electrical bias. A dramatic sign reversal within a voltage range of just a few tenths of an eV is predicted. This explains the observed sign reversal of spin polarization in recent experiments of electrical spin injection in Fe/GaAs(001) and related reversal of tunneling magnetoresistance through vertical Fe/GaAs/Fe trilayers.

  1. Platinum Monolayer on IrFe Core–Shell Nanoparticle Electrocatalysts for the Oxygen Reduction Reaction

    SciTech Connect (OSTI)

    Sasaki K.; Kuttiyiel, K.A.; Su, D.; Adzic, R.R.

    2012-04-19

    We synthesized high activity and stability platinum monolayer on IrFe core-shell nanoparticle electrocatalysts. Carbon-supported IrFe core-shell nanoparticles were synthesized by chemical reduction and subsequent thermal annealing. The formation of Ir shells on IrFe solid-solution alloy cores has been verified by scanning transmission electron microscopy coupled with energy-loss spectroscopy (EELS) and in situ X-ray absorption spectroscopy. The Pt monolayers were deposited on IrFe core-shell nanoparticles by galvanic replacement of underpotentially deposited Cu adatoms on the Ir shell surfaces. The specific and Pt mass activities for the ORR on the Pt monolayer on IrFe core-shell nanoparticle electrocatalyst are 0.46 mA/cm{sup 2} and 1.1 A/mg{sub Pt}, which are much higher than those on a commercial Pt/C electrocatalyst. High durability of Pt{sub ML}/IrFe/C has also been demonstrated by potential cycling tests. These high activity and durability observed can be ascribed to the structural and electronic interaction between the Pt monolayer and the IrFe core-shell nanoparticles.

  2. Magnetic ordering in tetragonal FeS: Evidence for strong itinerant spin fluctuations

    SciTech Connect (OSTI)

    Kwon, K.D.; Refson, K.; Bone, S.; Qiao, R.; Yang, W.; Liu, Z.; Sposito, G.

    2010-11-01

    Mackinawite is a naturally occurring layer-type FeS mineral important in biogeochemical cycles and, more recently, in the development of microbial fuel cells. Conflicting results have been published as to the magnetic properties of this mineral, with Moessbauer spectroscopy indicating no magnetic ordering down to 4.2 K but density functional theory (DFT) predicting an antiferromagnetic ground state, similar to the Fe-based high-temperature superconductors with which it is isostructural and for which it is known that magnetism is suppressed by strong itinerant spin fluctuations. We investigated this latter possibility for mackinawite using photoemission spectroscopy, near-edge x-ray absorption fine structure spectroscopy, and DFT computations. Our Fe 3{sub s} core-level photoemission spectrum of mackinawite showed a clear exchange-energy splitting (2.9 eV) consistent with a 1 {micro}{sub B} magnetic moment on the Fe ions, while the Fe L-edge x-ray absorption spectrum indicated rather delocalized Fe 3{sub d} electrons in mackinawite similar to those in Fe metal. Our DFT computations demonstrated that the ground state of mackinawite is single-stripe antiferromagnetic, with an Fe magnetic moment (2.7 {micro}{sub B}) that is significantly larger than the experimental estimate and has a strong dependence on the S height and lattice parameters. All of these trends signal the existence of strong itinerant spin fluctuations. If spin fluctuations prove to be mediators of electron pairing, we conjecture that mackinawite may be one of the simplest Fe-based superconductors.

  3. Fe3-xTixO4 Nanoparticles as Tunable Probes of Microbial Metal Oxidation

    SciTech Connect (OSTI)

    Liu, Juan; Pearce, Carolyn I.; Liu, Chongxuan; Wang, Zheming; Shi, Liang; Arenholz, Elke; Rosso, Kevin M.

    2013-05-14

    Present and emerging biotechnological applications for iron (oxyhydr)oxide nanomaterials depend on their interaction with microorganisms, as do their toxicity, transport, and fate in biological and environmental systems. However, mass or electron transfer along key molecular pathways at microbe-nanomaterial interfaces is extremely difficult to quantify because of system complexity. Inspired by Fe(II)-oxidizing microbes widespread in nature, we isolate and characterize one such pathway by examining the oxidation of Fe3-xTixO4 (magnetite-titanomagnetite) nanoparticles by the bacterial electron transfer enzyme MtoA, a decaheme c-type cytochrome. Oxidation by MtoA was studied as a function of the thermodynamic driving force for electron transfer by controlling the Ti(IV) doping content (x), which tunes the solid-state Fe(II)/Fe(III) ratio built into the nanoparticles. A higher Fe(II)/Fe(III) ratio appears to proportionally increase the electron transfer kinetics to the cytochrome. In situ x-ray diffraction indicated that during oxidation the spinel ferrite lattice remains intact while structural Fe(II) is progressively depleted. Surface and atomic site specific Fe L2,3-edge x-ray magnetic circular dichroism indicated that MtoA directly accesses magnetically-ordered B-sublattice Fe(II) at the interface. This study provides first quantitative insights into an isolated molecular pathway for biotransformation of iron (oxyhydr)oxide nanomaterials. And, more generally, it also illustrates new techniques for probing these pathways in detail, featuring use of tailored nanoparticles, purified metalloenzyme, and synchrotron x-ray absorption spectroscopies.

  4. 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 the total EFG parallel with the magnetic moment B. Display Omitted

  5. Magnetic structures of FeTiO{sub 3}-Fe{sub 2}O{sub 3} solid solution thin films studied by soft X-ray magnetic circular dichroism and ab initio multiplet calculations

    SciTech Connect (OSTI)

    Hojo, H. E-mail: fujita@dipole7.kuic.kyoto-u.ac.jp; Fujita, K. E-mail: fujita@dipole7.kuic.kyoto-u.ac.jp; Matoba, T.; Tanaka, K.; Ikeno, H.; Mizoguchi, T.; Tanaka, I.; Nakamura, T.; Takeda, Y.; Okane, T.

    2014-03-17

    The solid solutions between ilmenite (FeTiO{sub 3}) and hematite (?-Fe{sub 2}O{sub 3}) have recently attracted considerable attention as a spintronic material due to their interesting magnetic and electrical properties. In this study, the electronic and magnetic structures of epitaxially grown 0.6FeTiO{sub 3}·0.4Fe{sub 2}O{sub 3} solid solution thin films were investigated by combining x-ray absorption near-edge structure (XANES), x-ray magnetic circular dichroism (XMCD) for two different crystallographic projections, and first-principles theoretical calculations. The Fe L-edge XANES and XMCD spectra reveal that Fe is in the mixed-valent Fe{sup 2+}–Fe{sup 3+} states while Fe{sup 2+} ions are mainly responsible for the magnetization. Moreover, the experimental Fe L-edge XANES and XMCD spectra change depending on the incident x-ray directions, and the theoretical spectra explain such spectral features. We also find a large orbital magnetic moment, which can originate the magnetic anisotropy of this system. On the other hand, although the valence state of Ti was interpreted to be 4+ from the Ti L-edge XANES, XMCD signals indicate that some electrons are present in the Ti-3d orbital, which are coupled antiparallel to the magnetic moment of Fe{sup 2+} ions.

  6. Mixing antiferromagnets to tune NiFe-[IrMn/FeMn] interfacial spin-glasses, grains thermal stability, and related exchange bias properties

    SciTech Connect (OSTI)

    Akmaldinov, K.; Ducruet, C.; Portemont, C.; Joumard, I.; Prejbeanu, I. L.; Dieny, B.; Baltz, V.

    2014-05-07

    Spintronics devices and in particular thermally assisted magnetic random access memories require a wide range of ferromagnetic/antiferromagnetic (F/AF) exchange bias (EB) properties and subsequently of AF materials to fulfil diverse functionality requirements for the reference and storage. For the reference layer, large EB energies and high blocking temperature (T{sub B}) are required. In contrast, for the storage layer, mostly moderate T{sub B} are needed. One of the present issues is to find a storage layer with properties intermediate between those of IrMn and FeMn and in particular: (i) with a T{sub B} larger than FeMn for better stability at rest-T but lower than IrMn to reduce power consumption at write-T and (ii) with improved magnetic interfacial quality, i.e., with reduced interfacial glassy character for lower properties dispersions. To address this issue, the EB properties of F/AF based stacks were studied for various mixed [IrMn/FeMn] AFs. In addition to EB loop shifts, the F/AF magnetic interfacial qualities and the AF grains thermal stability are probed via measurements of the low- and high-temperature contributions to the T{sub B} distributions, respectively. A tuning of the above three parameters is observed when evolving from IrMn to FeMn via [IrMn/FeMn] repetitions.

  7. Magnetism and transport properties of epitaxial Fe-Ga thin films on GaAs(001)

    SciTech Connect (OSTI)

    Duong Anh Tuan; Shin, Yooleemi; Cho, Sunglae; Dang Duc Dung; Vo Thanh Son

    2012-04-01

    Epitaxial Fe-Ga thin films in disordered bcc {alpha}-Fe crystal structure (A2) have been grown on GaAs(001) by molecular beam epitaxy. The saturated magnetization (M{sub S}) decreased from 1371 to 1105 kA/m with increasing Ga concentration from 10.5 to 24.3 % at room temperature. The lattice parameter increased with the increase in Ga content because of the larger atomic radius of Ga atom than that of Fe. The increase in carrier density with Ga content caused in lower resistivity.

  8. Screening peach rootstocks for tolerance to iron deficiency stress: mechanisms of Fe?p3+ ?sreduction 

    E-Print Network [OSTI]

    Egilla, Jonathan Nda

    1989-01-01

    ) GF 677 and (b) Nemaguard with and without Fe. 34 5 pH changes in nutrient solution with roots of Ff?s ha"1nrnfnn L with and without Fe. 35 6 pH depression in de-tonized water over 4 hours by roots of 'Montclar' and h emaguard peach rootstocks.... , 1987), and Romheld et al. (1984) provided evidence that the protons are excreted by an ATP- dependent pump in the plasma membrane. Ric de Vos et al. (1986), proposed that Fe- deficiency induces the production of organic acids in the roots, which...

  9. Interface Structures of Ordered Fe and Gd Overlayers on W(110) from Photoelectron Diffraction

    SciTech Connect (OSTI)

    Tober, E.D.; Ynzunza, R.X.; Palomares, F.J.; Wang, Z.; Fadley, C.S. [Department of Physics, University of California at Davis, Davis, California 95616 (United States)] [Department of Physics, University of California at Davis, Davis, California 95616 (United States); Tober, E.D.; Ynzunza, R.X.; Palomares, F.J.; Wang, Z.; Van Hove, M.A.; Fadley, C.S. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)] [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Hussain, Z. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)] [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    1997-09-01

    Full-solid-angle and site-specific photoelectron diffraction data have been obtained from interface W atoms just beneath (1{times}1) Fe and (7{times}14) Gd monolayers on W(110) by utilizing the core level shift in the W f4{sub 7/2} spectrum. A comparison of experiment with multiple scattering calculations permits determining the Fe adsorption site and the relative interlayer spacing to the first and second W layers. These Fe results are also compared to those from the very different Gd overlayer and from the clean W(110) surface. {copyright} {ital 1997} {ital The American Physical Society}

  10. Enhancement of exchange bias and training effect in ion-beam sputtered Fe{sub 46}Mn{sub 54}/Ni{sub 81}Fe{sub 19} bilayers

    SciTech Connect (OSTI)

    Fulara, Himanshu; Chaudhary, Sujeet, E-mail: sujeetc@physics.iitd.ac.in; Kashyap, Subhash C. [Thin Film Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016 (India); Granville, Simon [Callaghan Innovation, PO Box 31310, Lower Hutt 5040 (New Zealand); The MacDiarmid Institute for Advanced Materials and Nanotechnology, Lower Hutt (New Zealand)

    2014-01-28

    We present a remarkable enhancement by 300% of the exchange-bias field at room temperature, without affecting the coercivity value, via optimum magnetic annealing (250?°C/3 kOe) in ion-beam sputtered FeMn(30?nm)/NiFe(10?nm) bilayers. This specific behavior has been attributed to a higher degree of ?-FeMn(111) orientation that offers more interfacial FeMn moments to get pinned with the moments of the adjacent NiFe layer. Unlike the absence of training effect at room temperature, a pronounced training effect and an accompanying magnetization reversal asymmetry are evidenced upon field cooling below 50?K due to the presence of biaxial exchange induced anisotropy across the interdiffused FeMn/NiFe interface. The present findings not only have technological significance but also are of relevance to the understanding of interfacial spin disorder and frustration in these exchange-biased systems.

  11. Structure of epitaxial (Fe,N) codoped rutile TiO2 thin films by x-ray absorption

    SciTech Connect (OSTI)

    Kaspar, Tiffany C.; Ney, A.; Mangham, Andrew N.; Heald, Steve M.; Joly, Yves; Ney, V.; Wilhelm, F.; Rogalev, A.; Yakou, Flora; Chambers, Scott A.

    2012-07-23

    Homoepitaxial thin films of Fe:TiO2 and (Fe,N):TiO2 were deposited on rutile(110) by molecular beam epitaxy. X-ray absorption near edge spectroscopy (XANES) spectra were collected at the Ti L-edge, Fe L-edge, O K-edge, N K-edge, and Ti K-edge. No evidence of structural disorder associated with a high concentration of oxygen vacancies is observed. Substitution of Fe for Ti could not be confirmed, although secondary phase Fe2O3 and metallic Fe can be ruled out. The similarity of the N K-edge spectra to O, and the presence of a strong x-ray linear dichroism (XLD) signal for the N K-edge, indicates that N is substitutional for O in the rutile lattice, and is not present as a secondary phase such as TiN. Simulations of the XANES spectra qualitatively confirm substitution, although N appears to be present in more than one local environment. Neither Fe:TiO2 nor (Fe,N):TiO2 exhibit intrinsic room temperature ferromagnetism, despite the presence of mixed valence Fe(II)/Fe(III) in the reduced (Fe,N):TiO2 film.

  12. Microstructure and magnetic properties of FeCo epitaxial thin films grown on MgO single-crystal substrates

    SciTech Connect (OSTI)

    Shikada, Kouhei; Ohtake, Mitsuru; Futamoto, Masaaki; Kirino, Fumiyoshi

    2009-04-01

    FeCo epitaxial films were prepared on MgO(100), MgO(110), and MgO(111) substrates by ultrahigh vacuum molecular beam epitaxy. FeCo thin films with (100), (211), and (110) planes parallel to the substrate surface grow on respective MgO substrates. FeCo/MgO interface structures are studied by high-resolution cross-sectional transmission electron microscopy and the epitaxial growth mechanism is discussed. Atomically sharp boundaries are recognized between the FeCo thin films and the MgO substrates where misfit dislocations are introduced in the FeCo thin films presumably to decrease the lattice misfits. Misfit dislocations are observed approximately every 9 and 1.4 nm in FeCo thin film at the FeCo/MgO(100) and the FeCo/MgO(110) interfaces, respectively. X-ray diffraction analysis indicates that the lattice spacing measured parallel to the single-crystal substrate surfaces are in agreement within 0.1% with those of the respective bulk values of Fe{sub 50}Co{sub 50} alloy crystal, showing that the FeCo film strain is very small. The magnetic anisotropies of these epitaxial films basically reflect the magnetocrystalline anisotropy of bulk FeCo alloy crystal.

  13. Effects of Cr and Ni on Interdiffusion and Reaction between U and Fe-Cr-Ni Alloys

    SciTech Connect (OSTI)

    K. Huang; Y. Park; L. Zhou; K.R. Coffey; Y.H. Sohn; B.H. Sencer; J. R. Kennedy

    2014-08-01

    Metallic U-alloy fuel cladded in steel has been examined for high temperature fast reactor technology wherein the fuel cladding chemical interaction is a challenge that requires a fundamental and quantitative understanding. In order to study the fundamental diffusional interactions between U with Fe and the alloying effect of Cr and Ni, solid-to-solid diffusion couples were assembled between pure U and Fe, Fe–15 wt.%Cr or Fe–15 wt.%Cr–15 wt.%Ni alloy, and annealed at high temperature ranging from 580 to 700 °C. The microstructures and concentration profiles that developed from the diffusion anneal were examined by scanning electron microscopy, and X-ray energy dispersive spectroscopy (XEDS), respectively. Thick U6Fe and thin UFe2 phases were observed to develop with solubilities: up to 2.5 at.% Ni in U6(Fe,Ni), up to 20 at.%Cr in U(Fe, Cr)2, and up to 7 at.%Cr and 14 at.% Ni in U(Fe, Cr, Ni)2. The interdiffusion and reactions in the U vs. Fe and U vs. Fe–Cr–Ni exhibited a similar temperature dependence, while the U vs. Fe–Cr diffusion couples, without the presence of Ni, yielded greater activation energy for the growth of intermetallic phases – lower growth rate at lower temperature but higher growth rate at higher temperature.

  14. Study of the effect of plasma-striking atmosphere on Fe-oxidation in thermal dc arc-plasma processing

    SciTech Connect (OSTI)

    Banerjee, I.; Khollam, Y. B.; Mahapatra, S. K.; Das, A. K.; Bhoraskar, S. V.

    2010-11-15

    The effect of plasma-striking atmosphere: air and air+Ar-gas on the crystallization of Fe-oxide phases was studied using dc thermal arc-plasma processing route. The powders were characterized by x-ray diffraction, vibrating sample magnetometry, transmission electron microscopy, and Moessbauer spectroscopy techniques. At room temperature and O{sub 2} rich atmosphere, arc-evaporated Fe{sup 2+} ions oxidize into either {gamma}-Fe{sub 2}O{sub 3} or Fe{sub 3}O{sub 4} depending upon the combining ratio of Fe with molecular O{sub 2}. Fe/O ratio could be adjusted using proper flow rate of Ar gas to crystallize the pure {gamma}-Fe{sub 2}O{sub 3}.

  15. Determination of the Fe magnetic anisotropies and the CoO frozen spins in epitaxial CoO/Fe/Ag(001)

    SciTech Connect (OSTI)

    Meng, J. Li, Y.; Park, J. S.; Jenkins, C. A.; Arenholz, E.; Scholl, A.; Tan, A.; Son, H.; Zhao, H. W.; Hwang, Chanyong; Qiu, Z. Q.

    2011-04-28

    CoO/Fe/Ag(001) films were grown epitaxially and studied by X-ray Magnetic Circular Dichroism (XMCD) and X-ray Magnetic Linear Dichroism (XMLD). After field cooling along the Fe[100] axis to 80 K, exchange bias, uniaxial anisotropy, and 4-fold anisotropy of the films were determined by hysteresis loop and XMCD measurements by rotating the Fe magnetization within the film plane. The CoO frozen spins were determined by XMLD measurement as a function of CoO thickness.We find that among the exchange bias, uniaxial anisotropy, and 4-fold anisotropy, only the uniaxial magnetic anisotropy follows thickness dependence of the CoO frozen spins.

  16. Large Scale DD Simulation Results for Crystal Plasticity Parameters in Fe-Cr And Fe-Ni Systems

    SciTech Connect (OSTI)

    Zbib, Hussein M.; Li, Dongsheng; Sun, Xin; Khaleel, Mohammad A.

    2012-04-30

    The development of viable nuclear energy source depends on ensuring structural materials integrity. Structural materials in nuclear reactors will operate in harsh radiation conditions coupled with high level hydrogen and helium production, as well as formation of high density of point defects and defect clusters, and thus will experience severe degradation of mechanical properties. Therefore, the main objective of this work is to develop a capability that predicts aging behavior and in-service lifetime of nuclear reactor components and, thus provide an instrumental tool for tailoring materials design and development for application in future nuclear reactor technologies. Towards this end goal, the long term effort is to develop a physically based multiscale modeling hierarchy, validated and verified, to address outstanding questions regarding the effects of irradiation on materials microstructure and mechanical properties during extended service in the fission and fusion environments. The focus of the current investigation is on modern steels for use in nuclear reactors including high strength ferritic-martensitic steels (Fe-Cr-Ni alloys). The effort is to develop a predicative capability for the influence of irradiation on mechanical behavior. Irradiation hardening is related to structural information crossing different length scales, such as composition, dislocation, and crystal orientation distribution. To predict effective hardening, the influence factors along different length scales should be considered. Therefore, a hierarchical upscaling methodology is implemented in this work in which relevant information is passed between models at three scales, namely, from molecular dynamics to dislocation dynamics to dislocation-based crystal plasticity. The molecular dynamics (MD) was used to predict the dislocation mobility in body centered cubic (bcc) Fe and its Ni and Cr alloys. The results are then passed on to dislocation dynamics to predict the critical resolved shear stress (CRSS) from the evolution of local dislocation and defects. In this report the focus is on the results obtained from large scale dislocation dynamics simulations. The effect of defect density, materials structure was investigated, and evolution laws are obtained. These results will form the bases for the development of evolution and hardening laws for a dislocation-based crystal plasticity framework. The hierarchical upscaling method being developed in this project can provide a guidance tool to evaluate performance of structural materials for next-generation nuclear reactors. Combined with other tools developed in the Nuclear Energy Advanced Modeling and Simulation (NEAMS) program, the models developed will have more impact in improving the reliability of current reactors and affordability of new reactors.

  17. Z-STEM Imaging of Chemical Ordering in FePt Magnetic Nanoparticles

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

    Z-STEM Imaging of Chemical Ordering in FePt Magnetic Nanoparticles J.E. Wittig, M.S. Wellons and C.M. Lukehart, Vanderbilt University J. Bentley and L.F. Allard, Oak Ridge National...

  18. FE's Advanced Combustion R&D Seeks Innovative Ways to Lower Cost...

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

    Learn more about the FE Advanced Combustion R&D. You've probably heard about carbon capture and storage (CCS), a suite of technologies designed to capture and store carbon dioxide...

  19. Enhancement of PAH biomineralization rates by cyclodextrins under Fe(III)-reducing conditions

    E-Print Network [OSTI]

    Ramsay, Juliana

    biodegradation whereby the indi- genous microorganisms degrade the contaminants without intervention. However. Keywords: Cyclodextrin; Fe(III) reduction; Mineralization; PAH bioavailability; Polyaromatic hydrocarbons 1. Introduction Since polycyclic aromatic hydrocarbons (PAHs) are potentially toxic, mutagenic, and carcinogenic

  20. Enhanced Magnetism of Fe3O4 Nanoparticles with Ga Doping

    SciTech Connect (OSTI)

    Pool, V. L.; Klem, M. T.; Chorney, C. L.; Arenholz, E.; Idzerda, Y.U.

    2010-10-22

    Magnetic (Ga{sub x}Fe{sub 1-x}){sub 3}O{sub 4} nanoparticles with 5%-33% gallium doping (x = 0.05-0.33) were measured using x-ray absorption spectroscopy and x-ray magnetic circular dichroism to determine that the Ga dopant is substituting for Fe{sub 3+} as Ga{sub 3+} in the tetrahedral A-site of the spinel structure, resulting in an overall increase in the total moment of the material. Frequency-dependent alternating-current magnetic susceptibility measurements showed these particles to be weakly interacting with a reduction of the cubic anisotropy energy term with Ga concentration. The element-specific dichroism spectra show that the average Fe moment is observed to increase with Ga concentration, a result consistent with the replacement of A-site Fe by Ga.

  1. Air Flow North America Corp. – FE Dkt. No. 14-53-LNG (Re-export)

    Broader source: Energy.gov [DOE]

    The Office of Fossil Energy (FE) of the Department of Energy (DOE) gives notice of receipt of an application filed on March 25, 2014, by Air Flow North America Corp. (AIR FLOW) requesting short...

  2. CORROSION OF Fe-10Al-Cr ALLOYS BY COAL CHAR

    E-Print Network [OSTI]

    Gordon, B.A.

    2011-01-01

    Potent.ials Encountered in Coal Conversion Systems", NASA TNof Illinois #6 ash and coal char. Figure 1. Cross sectionsof Fe-lOAl-Cr Alloys by Coal Char B. A. Gordon and V.

  3. Graphene Modified LiFePO4 Cathode Materials for High Power Lithium ion Batteries

    SciTech Connect (OSTI)

    Zhou, X.; Wang, F.; Zhu, Y.; Liu, Z.

    2011-01-24

    Graphene-modified LiFePO{sub 4} composite has been developed as a Li-ion battery cathode material with excellent high-rate capability and cycling stability. The composite was prepared with LiFePO{sub 4} nanoparticles and graphene oxide nanosheets by spray-drying and annealing processes. The LiFePO{sub 4} primary nanoparticles embedded in micro-sized spherical secondary particles were wrapped homogeneously and loosely with a graphene 3D network. Such a special nanostructure facilitated electron migration throughout the secondary particles, while the presence of abundant voids between the LiFePO{sub 4} nanoparticles and graphene sheets was beneficial for Li{sup +} diffusion. The composite cathode material could deliver a capacity of 70 mAh g{sup -1} at 60C discharge rate and showed a capacity decay rate of <15% when cycled under 10C charging and 20C discharging for 1000 times.

  4. Mass Measurements of Proton-Rich Nuclei Fe-50 and Ni-54 

    E-Print Network [OSTI]

    Tribble, Robert E.; Cossairt, J. D.; May, D. P.; Kenefick, R. A.

    1977-01-01

    to different kinematic shifts for the 'He' s from the light (A=12) and heavy (A =54, 58) mass targets. Calibrated 'He spectra from Fe and "Ni are shown in Fig. 1. From previous ('He, 'He) measurements, the cross sections to "Fe and ' Ni were expected... are TABLE I. Properties of Fe and 5 Ni. All entries are in MeV. Nuclide Expt. Mass excess Garvey and Kelson ~ Coulomb energy ~ip ~2p Coulomb energy 50Fe -34.48 +0.06 -39.21 +0.05 -34.50 39.27 -34.472 +0.013 -39.296 +0.013 4.16 6.24 8.93 +0.06 3...

  5. Factors Influencing the Quality of Carbon Coatings on LiFePO4

    E-Print Network [OSTI]

    Wilcox, James D.; Doeff, Marca M.; Marcinek, Marek; Kostecki, Robert

    2006-01-01

    the Quality of Carbon Coatings on LiFePO 4 James D. Wilcoxamounts of a less-conductive coating. It has also been shownin markedly improved coatings, as will be shown below.

  6. The Utility of FeVO4 in Combination with Stabilized Titanias...

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

    of FeVO4 in Combination with Stabilized Titanias for Mobile SCR Application Selective catalytic reduction studies with ammoniaNO model gas mixtures were used to screen mixed...

  7. The Effects of Hydrocarbons on NOx Reduction over Fe-based SCR Catalyst

    Broader source: Energy.gov [DOE]

    Study of effects of hydrocarbons on ammonia storage and NOx reduction over a commercial Fe-zeolite SCR catalyst to understand catalyst behaviors at low temperatures and improve NOx reduction performance and reduce system cost

  8. Performance Evaluation of Microporous Separator in Fe/V Redox Flow Battery

    SciTech Connect (OSTI)

    Wei, Xiaoliang; Luo, Qingtao; Li, Bin; Nie, Zimin; Miller, Eric; Chambers, Jeff; Sprenkle, Vincent L.; Wang, Wei

    2013-04-08

    The newly developed Fe/V redox flow battery has demonstrated attractive cell performance. However, the deliverable energy density is relatively inferior due to the low cell voltage. To compensate this disadvantage and compete with other redox flow battery systems, cost reduction of the Fe/V system is necessary. This paper describes evaluation of hydrocarbon-based Daramic® microporous separators for use in the Fe/V system. The separator B having ion exchange capacity demonstrated excellent capacity retention capability. Separator B exhibited energy efficiency above 65% over a broad temperature range of 5-50oC and at current densities up to 80mA/cm2. Plus, separator B is very inexpensive and has exceptional mechanical properties. Therefore, this separator shows great potential to replace the expensive Nafion® membrane. This will drive down the capital cost and make the Fe/V system a promising low-cost energy storage technology.

  9. Symmetry-Defying Iron Pyrite (FeS2) Nanocrystals through Oriented Attachment

    E-Print Network [OSTI]

    Gong, Maogang; Kirkeminde, Alec; Ren, Shenqiang

    2013-06-28

    , controlling FeS2 nanocrystal formation (composition, size, shape, stoichiometry, etc.) and defect mitigation still remains a challenge. These problems represent significant limitations in the ability to control electrical, optical and electrochemical...

  10. Reactivity of nanocolloidal particles -Fe2O3 at charged interfaces: 2-Electrochemical conversion.

    E-Print Network [OSTI]

    Boyer, Edmond

    synthesis of magnetic and conductive liquids. The reactivity of charged colloidal10 particles occurs in two by methyl viologen), nanoparticles of hematite and goethite (-FeOOH: d = 50 nm) are invo

  11. Pressure-temperature stability studies of FeOOH using x-ray diffraction

    E-Print Network [OSTI]

    Gleason, Arianna E.

    2009-01-01

    size effect on the reaction: goethite = hematite + water.and heat capacity of goethite (alpha-FeOOH), lepidocrocite (bonded O…O distances in goethite at high pressure. American

  12. Hydrated goethite (alpha-FeOOH) (100) interface structure: Ordered water and surface functional groups.

    E-Print Network [OSTI]

    Ghose, S.K.

    2011-01-01

    and the (010) surface of goethite. Geochem. Trans. 9, 1–16.Con?rmation of the surface structure of goethite (a-FeOOH. ,phosphated goethite by infrared spectroscopy. Soil Sci. Soc.

  13. Ferromagnetism and Nonmetallic Transport of Thin-Film ? - FeSi 2 : A Stabilized Metastable Material

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

    Cao, Guixin; Singh, D.?J.; Zhang, X.-G.; Samolyuk, German; Qiao, Liang; Parish, Chad; Jin, Ke; Zhang, Yanwen; Guo, Hangwen; Tang, Siwei; et al

    2015-04-07

    A metastable phase ?-FeSi? was epitaxially stabilized on a silicon substrate using pulsed laser deposition. Nonmetallic and ferromagnetic behaviors are tailored on ?-FeSi? (111) thin films, while the bulk material of ?-FeSi? is metallic and nonmagnetic. The transport property of the films renders two different conducting states with a strong crossover at 50 K, which is accompanied by the onset of a ferromagnetic transition as well as a substantial magnetoresistance. These experimental results are discussed in terms of the unusual electronic structure of ?-FeSi? obtained within density functional calculations and Boltzmann transport calculations with and without strain. Our finding shedsmore »light on achieving ferromagnetic semiconductors through both their structure and doping tailoring, and provides an example of a tailored material with rich functionalities for both basic research and practical applications.« less

  14. Ferromagnetism and Nonmetallic Transport of Thin-Film ? - FeSi 2 : A Stabilized Metastable Material

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

    Cao, Guixin; Singh, D.?J.; Zhang, X.-G.; Samolyuk, German; Qiao, Liang; Parish, Chad; Jin, Ke; Zhang, Yanwen; Guo, Hangwen; Tang, Siwei; Wang, Wenbin; Yi, Jieyu; Cantoni, Claudia; Siemons, Wolter; Payzant, E. Andrew; Biegalski, Michael; Ward, T.?Z.; Mandrus, David; Stocks, G.?M.; Gai, Zheng

    2015-04-01

    A metastable phase ?-FeSi? was epitaxially stabilized on a silicon substrate using pulsed laser deposition. Nonmetallic and ferromagnetic behaviors are tailored on ?-FeSi? (111) thin films, while the bulk material of ?-FeSi? is metallic and nonmagnetic. The transport property of the films renders two different conducting states with a strong crossover at 50 K, which is accompanied by the onset of a ferromagnetic transition as well as a substantial magnetoresistance. These experimental results are discussed in terms of the unusual electronic structure of ?-FeSi? obtained within density functional calculations and Boltzmann transport calculations with and without strain. Our finding sheds light on achieving ferromagnetic semiconductors through both their structure and doping tailoring, and provides an example of a tailored material with rich functionalities for both basic research and practical applications.

  15. Freeport LNG Expansion, L.P. and FLNG Liquefaction, LLC - FE...

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

    0-161-LNG Freeport LNG Expansion, L.P. and FLNG Liquefaction, LLC - FE Dkt. No. 10-161-LNG On May 17, 2013, the Office of Fossil Energy of the Department of Energy (DOEFE) issued...

  16. Flint Hills Resources, LP- FE Dkt. No. 15-168-LNG

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Office of Fossil Energy (FE) of the Department of Energy (DOE) gives notice of receipt of an application, filed on November 5, 2015, by Flint Hills Resources, LP (Flint Hills), requesting long...

  17. Sabine Pass Liquefaction, LLC FE Dkt. No 15-171-LNG

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Office of Fossil Energy (FE) of the Department of Energy (DOE) gives notice of receipt of an application (Application), filed on November 6, 2015, by Sabine Pass Liquefaction, LLC (Sabine Pass)...

  18. Evaluation of Quasicrystal Al-Cu-Fe Alloys for Tribological Applications 

    E-Print Network [OSTI]

    Nabelsi, Nezar

    2013-07-22

    This research investigated the tribological performance of a composite material, formed from an ultra high molecular weight polyethylene (UHMWPE) matrix and quasicrystalline Al-Cu-Fe alloy powders. An evaluation was conducted for the microstructure...

  19. Critical analysis on nanostructured CoFeB synthetic orthogonal ferrimagnet

    SciTech Connect (OSTI)

    Chen, Y. S.; Lin, J. G., E-mail: jglin@ntu.edu.tw [Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan (China); Cheng, Chih-Wei; Chern, G. [Department of Physics, National Chung Cheng University, Chia-Yi 621, Taiwan (China)

    2014-09-21

    Critical analysis on the magnetic properties of synthetic ferrimagnet (SyF), Ta/MgO/CoFeB/Ru/CoFeB/MgO/Ta, is demonstrated via both static and dynamic techniques. With the Ru thickness being 2.3 nm, the coupling between two CoFeB layers becomes orthogonal, which can be used for spin-transfer-torque nano-oscillator (STNO). The fitting of angular dependent ferromagnetic resonance (FMR) allows the precise determination of magnetic anisotropy of each CoFeB layer, the relative magnetizations and the exchange field near the frequency of STNO applications. In addition, the mechanism of resonance broadening at out-of-plane direction is identified to be magnetic inhomogeneity by fitting the angular dependent linewidth of FMR spectra, which provides indispensable information for the future design of STNO devices.

  20. Transition-metal and metalloid substitutions in L1(0)-ordered FeNi

    SciTech Connect (OSTI)

    Manchanda, P; Skomski, R; Bordeaux, N; Lewis, LH; Kashyap, A

    2014-05-07

    The effect of atomic substitutions on the magnetization, exchange, and magnetocrystalline anisotropy energy of L1(0)-ordered FeNi (tetrataenite) is computationally investigated. The compound naturally occurs in meteorites but has attracted renewed attention as a potential material for permanent magnets, and elemental additives will likely be necessary to facilitate the phase formation. Our density functional theory calculations use the Vienna ab-initio simulation package, applied to 4-atom unit cells of Fe2XNi and 32-atom supercells (X = Al, P, S, Ti, V, Cr, Mn, Fe, Co). While it is found that most additives deteriorate the magnetic properties, there are exceptions: excess substitutional Fe and Co additions improve the magnetization, whereas Cr, S, and interstitial B additions improve the magnetocrystalline anisotropy. (C) 2014 AIP Publishing LLC.

  1. Transition-metal and metalloid substitutions in L1{sub 0}-ordered FeNi

    SciTech Connect (OSTI)

    Manchanda, Priyanka; Skomski, Ralph; Bordeaux, N.; Lewis, L. H.; Kashyap, Arti

    2014-05-07

    The effect of atomic substitutions on the magnetization, exchange, and magnetocrystalline anisotropy energy of L1{sub 0}-ordered FeNi (tetrataenite) is computationally investigated. The compound naturally occurs in meteorites but has attracted renewed attention as a potential material for permanent magnets, and elemental additives will likely be necessary to facilitate the phase formation. Our density functional theory calculations use the Vienna ab-initio simulation package, applied to 4-atom unit cells of Fe{sub 2}XNi and 32-atom supercells (X?=?Al, P, S, Ti, V, Cr, Mn, Fe, Co). While it is found that most additives deteriorate the magnetic properties, there are exceptions: excess substitutional Fe and Co additions improve the magnetization, whereas Cr, S, and interstitial B additions improve the magnetocrystalline anisotropy.

  2. Reductive dechlorination of chlorinated aliphatic hydrocarbons by Fe(ii) in degradative solidification/stabilization 

    E-Print Network [OSTI]

    Jung, Bahng Mi

    2007-04-25

    This dissertation examines the applicability of the iron-based degradative solidification/stabilization (DS/S-Fe(II)) to various chlorinated aliphatic hydrocarbons (CAHs) that are common chemicals of concern at contaminated sites. The research...

  3. Impact of Fe (III) on the Performance of Viscoelastic Surfactant-Based Acids 

    E-Print Network [OSTI]

    Shu, Yi

    2013-08-02

    Viscoelastic surfactant (VES)-based acid systems have been used successfully in matrix and acid fracturing treatments. However, the existence of Fe (III) as a contaminant in such systems may lead to many problems, due to interactions between VES...

  4. Magnetism of NiMn2O4-Fe3O4 spinel interfaces

    E-Print Network [OSTI]

    Nelson-Cheeseman, B. B.

    2007-01-01

    2 O 4 –Fe 3 O 4 spinel interfaces B. B. Nelson-Cheeseman,isostructural spinel-spinel interface of NiMn 2 O 4 (NMO)–Feis preserved, both bulk and interface sensitive measurements

  5. Atomic structure of postgrowth annealed epitaxial Fe/(001)GaAs interfaces

    E-Print Network [OSTI]

    LeBeau, James; Hu, Qi O.; Palmstrom, Christopher; Stemmer, Susanne

    2008-01-01

    line pro?le across the interface along the line indicated inHAADF images of the GaAs/Fe interface along ?a? ?11 0? GaAsindicates the location of an interface step. Arrows in ?b?

  6. Strain relaxation and enhanced perpendicular magnetic anisotropy in BiFeO{sub 3}:CoFe{sub 2}O{sub 4} vertically aligned nanocomposite thin films

    SciTech Connect (OSTI)

    Zhang, Wenrui; Jiao, Liang; Li, Leigang [Department of Materials Science and Engineering, Texas A and M University, College Station, Texas 77843 (United States); Jian, Jie; Khatkhatay, Fauzia; Chu, Frank [Department of Electrical and Computer Engineering, Texas A and M University, College Station, Texas 77843 (United States); Chen, Aiping [Department of Electrical and Computer Engineering, Texas A and M University, College Station, Texas 77843 (United States); Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Jia, Quanxi [Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); MacManus-Driscoll, Judith L. [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ (United Kingdom); Wang, Haiyan, E-mail: wangh@ece.tamu.edu [Department of Materials Science and Engineering, Texas A and M University, College Station, Texas 77843 (United States); Department of Electrical and Computer Engineering, Texas A and M University, College Station, Texas 77843 (United States)

    2014-02-10

    Self-assembled BiFeO{sub 3}:CoFe{sub 2}O{sub 4} (BFO:CFO) vertically aligned nanocomposite thin films have been fabricated on SrTiO{sub 3} (001) substrates using pulsed laser deposition. The strain relaxation mechanism between BFO and CFO with a large lattice mismatch has been studied by X-ray diffraction and transmission electron microscopy. The as-prepared nanocomposite films exhibit enhanced perpendicular magnetic anisotropy as the BFO composition increases. Different anisotropy sources have been investigated, suggesting that spin-flop coupling between antiferromagnetic BFO and ferrimagnetic CFO plays a dominant role in enhancing the uniaxial magnetic anisotropy.

  7. Light, alpha, and Fe-peak element abundances in the galactic bulge

    SciTech Connect (OSTI)

    Johnson, Christian I.; Rich, R. Michael; Kobayashi, Chiaki; Kunder, Andrea; Koch, Andreas E-mail: rmr@astro.ucla.edu E-mail: akunder@aip.de

    2014-10-01

    We present radial velocities and chemical abundances of O, Na, Mg, Al, Si, Ca, Cr, Fe, Co, Ni, and Cu for a sample of 156 red giant branch stars in two Galactic bulge fields centered near (l, b) = (+5.25,–3.02) and (0,–12). The (+5.25,–3.02) field also includes observations of the bulge globular cluster NGC 6553. The results are based on high-resolution (R ? 20,000), high signal-to-noise ration (S/N ? 70) FLAMES-GIRAFFE spectra obtained through the European Southern Observatory archive. However, we only selected a subset of the original observations that included spectra with both high S/N and that did not show strong TiO absorption bands. This work extends previous analyses of this data set beyond Fe and the ?-elements Mg, Si, Ca, and Ti. While we find reasonable agreement with past work, the data presented here indicate that the bulge may exhibit a different chemical composition than the local thick disk, especially at [Fe/H] ? –0.5. In particular, the bulge [?/Fe] ratios may remain enhanced to a slightly higher [Fe/H] than the thick disk, and the Fe-peak elements Co, Ni, and Cu appear enhanced compared to the disk. There is also some evidence that the [Na/Fe] (but not [Al/Fe]) trends between the bulge and local disk may be different at low and high metallicity. We also find that the velocity dispersion decreases as a function of increasing [Fe/H] for both fields, and do not detect any significant cold, high-velocity populations. A comparison with chemical enrichment models indicates that a significant fraction of hypernovae may be required to explain the bulge abundance trends, and that initial mass functions that are steep, top-heavy (and do not include strong outflow), or truncated to avoid including contributions from stars >40 M {sub ?} are ruled out, in particular because of disagreement with the Fe-peak abundance data. For most elements, the NGC 6553 stars exhibit abundance trends nearly identical to comparable metallicity bulge field stars. However, the star-to-star scatter and mean [Na/Fe] ratios appear higher in the cluster, perhaps indicating additional self-enrichment.

  8. Surface modification to improve fireside corrosion resistance of Fe-Cr ferritic steels

    DOE Patents [OSTI]

    Park, Jong-Hee (Clarendon Hills, IL); Natesan, Krishnamurti (Naperville, IL); Rink, David L. (Mokena, IL)

    2010-03-16

    An article of manufacture and a method for providing an Fe--Cr ferritic steel article of manufacture having a surface layer modification for corrosion resistance. Fe--Cr ferritic steels can be modified to enhance their corrosion resistance to liquid coal ash and other chemical environments, which have chlorides or sulfates containing active species. The steel is modified to form an aluminide/silicide passivating layer to reduce such corrosion.

  9. Heat treatment of NiCrFe alloy to optimize resistance to intergrannular stress corrosion

    DOE Patents [OSTI]

    Steeves, Arthur F. (Schenectady, NY); Bibb, Albert E. (Clifton Park, NY)

    1984-01-01

    A process of producing a NiCrFe alloy having a high resistance to stress corrosion cracking comprising heating a NiCrFe alloy to a temperature sufficient to enable the carbon present in the alloy body in the form of carbide deposits to enter into solution, rapidly cool the alloy body, and heat the cooled body to a temperature between 1100.degree. to 1500.degree. F. for about 1 to 30 hours.

  10. Multiferroic BaTiO3-CoFe2O4 Nanostructures

    E-Print Network [OSTI]

    Ramesh, R.

    an additional degree of freedom in the design of actuators, transducers, and storage devices. HoweverMultiferroic BaTiO3-CoFe2O4 Nanostructures H. Zheng,1 J. Wang,1 S. E. Lofland,3 Z. Ma,1 L. Mohaddes and magnetic order param- eters in a nanostructured BaTiO3-CoFe2O4 ferroelectromagnet. This facilitates

  11. Introduction: Bencubbin-like meteorites (CB) are metal-rich chondritic breccias containing about 60 vol% metallic (Fe,Ni) [1]. Unlike the CBa (Becubbin, Weatherford,

    E-Print Network [OSTI]

    vol% metallic (Fe,Ni) [1]. Unlike the CBa (Becubbin, Weatherford, Gujba) subgroup, the CBb (HH 237 al. [4] found that the Ir/Fe, Pd/Fe and Ni/Fe ratios in unzoned metal grains in the CBa chondrites that the components of CBa and CBb chondrites formed in a giant impact: SO chondrules and unzoned metal in Gujba

  12. Doctrina breve muy provechosa de las cosas que pertenecen a la fe católica y a nuestra cristiandad en estilo llano para común inteligencia 

    E-Print Network [OSTI]

    Zumá rraga, Juan de, 1468-1548 Doctrina breve muy provechosa de las cosas que pertenecen a la fe cató lica y a nuestra cristiandad en estilo llano para comú n inteligencia  Zumá rraga, Juan de, 1468-1548; 1544 Ligand effects on bioinspired iron complexes  Mejia Rodriguez, Ma. del Rosario

    2005-11-01

    - phosphaadamantane, PTA, coordinates to the Fe centers forming the disubstituted complex (m-pdt)[Fe(CO)2PTA]2, which presents one PTA in each iron in a transoid arrangement. Substitution of one CO ligand in the (m-pdt)[Fe(CO)3]2 parent complex forms the asymmetric (m-pdt)[Fe...

  13. Magnetron-sputter epitaxy of {beta}-FeSi{sub 2}(220)/Si(111) and {beta}-FeSi{sub 2}(431)/Si(001) thin films at elevated temperatures

    SciTech Connect (OSTI)

    Liu Hongfei; Tan Chengcheh; Chi Dongzhi [Institute of Materials Research and Engineering (IMRE), A-STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602 (Singapore)

    2012-07-15

    {beta}-FeSi{sub 2} thin films have been grown on Si(111) and Si(001) substrates by magnetron-sputter epitaxy at 700 Degree-Sign C. On Si(111), the growth is consistent with the commonly observed orientation of [001]{beta}-FeSi{sub 2}(220)//[1-10]Si(111) having three variants, in-plane rotated 120 Degree-Sign with respect to one another. However, on Si(001), under the same growth conditions, the growth is dominated by [-111]{beta}-FeSi{sub 2}(431)//[110]Si(001) with four variants, which is hitherto unknown for growing {beta}-FeSi{sub 2}. Photoelectron spectra reveal negligible differences in the valance-band and Fe2p core-level between {beta}-FeSi{sub 2} grown on Si(111) and Si(001) but an apparent increased Si-oxidization on the surface of {beta}-FeSi{sub 2}/Si(001). This phenomenon is discussed and attributed to the Si-surface termination effect, which also suggests that the Si/Fe ratio on the surface of {beta}-FeSi{sub 2}(431)/Si(001) is larger than that on the surface of {beta}-FeSi{sub 2}(220)/Si(111).

  14. Fischer-Tropsch Synthesis. Reduction Behavior and Catalytic Activity of Fe-Ce Systems

    SciTech Connect (OSTI)

    Perez-Alonso, F.J.; Ojeda, M.; Herranz, T.; Fierro, J.L.G. [Instituto de Catalisis y Petroleoquimica (CSIC), c/Marie Curie 2, 28049 Madrid (Spain); Bengoa, J.F.; Marchetti, S.G. [CINDECA, Facultad de Ciencias Exactas, Facultad de Ingenieria, UNLP, CICBA, CONICET, Calle 47 No 257, 1900 La Plata (Argentina)

    2005-04-26

    Several Fe-Ce catalysts for FT synthesis were prepared following two different methods: coprecipitation from Fe and Ce nitrate solutions and a physical mixture of pure Fe and Ce precursors. The iron phases present in the activated catalysts were identified by XRD and Moessbauer spectroscopy. A good correlation between both techniques was found. The results revealed that the cerium oxide in the samples prepared by coprecipitation produces two effects: (i), stabilization of metastable species (Fe1-xO), and (ii), a decrease in the crystallite size of the iron species upon increasing Ce-contents, as inferred from an increase in superparamagnetic species. The catalysts were tested in CO hydrogenation in a flow reactor. It was found that selectivity towards light olefins increases for the coprecipitated Ce-containing catalysts, whereas CO conversion followed the opposite trend. Since the Fe1-xO phase was detected in these catalysts, it is suggested that the formation of the Fe1-xO phase would be responsible for the drop in catalytic activity.

  15. Optimization of LiFePO4 Nanoparticle Suspensions with Polyethyleneimine for Aqueous Processing

    SciTech Connect (OSTI)

    Li, Jianlin; Armstrong, Beth L; Kiggans, Jim; Daniel, Claus; Wood III, David L

    2012-01-01

    Addition of dispersants to aqueous based lithium-ion battery electrode formulations containing LiFePO{sub 4} is critical to obtaining a stable suspension. The resulting colloidal suspensions enable dramatically improved coating deposition when processing electrodes. This research examines the colloidal chemistry modifications based on polyethyleneimine (PEI) addition and dispersion characterization required to produce high quality electrode formulations and coatings for LiFePO{sub 4} active cathode material. The isoelectric point, a key parameter in characterizing colloidal dispersion stability, of LiFePO{sub 4} and super P C45 were determined to be pH = 4.3 and 3.4, respectively. PEI, a cationic surfactant, was found to be an effective dispersant. It is demonstrated that 1.0 wt % and 0.5 wt % PEI were required to stabilize the LiFePO{sub 4} and super P C45 suspension, respectively. LiFePO{sub 4} cathode suspensions with 1.5 wt % PEI demonstrated the best dispersibility of all components, as evidenced by viscosity and agglomerate size of the suspensions and elemental distribution within dry cathodes. The addition of PEI significantly improved the LiFePO{sub 4} performance.

  16. A New Fe/V Redox Flow Battery Using Sulfuric/Chloric Mixed Acid Supporting Electrolyte

    SciTech Connect (OSTI)

    Wang, Wei; Nie, Zimin; Chen, Baowei; Chen, Feng; Luo, Qingtao; Wei, Xiaoliang; Xia, Guanguang; Skyllas-Kazacos, Maria; Li, Liyu; Yang, Zhenguo

    2012-04-01

    A redox flow battery using Fe2+/Fe3+ and V2+/V3+ redox couples in chloric/sulphuric mixed acid supporting electrolyte was investigated for potential stationary energy storage applications. The Fe/V redox flow cell using mixed reactant solutions operated within a voltage window of 0.5-1.35 V with a nearly 100% utilization ratio and demonstrated stable cycling over 100 cycles with energy efficiency > 80% and no capacity fading at room temperature. A 25% improvement in the discharge energy density of the Fe/V cell was achieved compared with the previous reported Fe/V cell using pure chloride acid supporting electrolyte. Stable performance was also achieved in the temperature range between 0 C and 50 C as well as using microporous separator as the membrane. The improved electrochemical performance at room temperature makes the Fe/V redox flow battery a promising option as a stationary energy storage device to enable renewable integration and stabilization of the electrical grid.

  17. Bulk amorphous Pd{endash}Ni{endash}Fe{endash}P alloys: Preparation and characterization

    SciTech Connect (OSTI)

    Shen, T.D.; He, Y.; Schwarz, R.B. [Materials Science and Technology Division, MS K765, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    1999-05-01

    Bulk amorphous alloys of Pd{sub x}Ni{sub y}Fe{sub 80{minus}x{minus}y}P{sub 20} (25{le}x{le}60, 20{le}y{le}55, x+y{ge}60) were prepared by a flux-melting and water-quenching method. Seven-mm diameter glassy rods of Pd{sub 40}Ni{sub 40{minus}x}Fe{sub x}P{sub 20} (0{le}x{le}20) were studied in greater detail. For these alloys, the difference between the crystallization and glass transition temperatures ranges from 102 K for x=0 to 53 K for x=20. In this composition range, the reduced glass transition temperature, T{sub rg}, ranges from 0.66 to 0.57. The change in density upon crystallization ranges from 0.24{plus_minus}0.04{percent} for x=0 to 1.33{plus_minus}0.24{percent} for x=10. The partial molar volume of Fe in amorphous Pd{sub 40}Ni{sub 40{minus}x}Fe{sub x}P{sub 20} alloys is significantly larger than the molar volume of (metastable) fcc Fe. This, as well as a comparison with the molar volumes of crystalline compounds, suggests chemically selective Fe{endash}Pd bonding in these glasses. {copyright} {ital 1999 Materials Research Society.}

  18. Pressure-temperature stability studies of FeOOH using x-ray diffraction

    SciTech Connect (OSTI)

    Gleason, Arianna E.; Jeanloz, Raymond; Kunz, Martin

    2008-07-21

    The Mie-Gruneisen formalism is used to fit a Birch-Murnaghan equation of state to high-temperature (T), high-pressure (P) X-ray diffraction unit-cell volume (V) measurements on synthetic goethite (alpha-FeOOH) to combined conditions of T = 23-250o C and P = 0-29.4 GPa. We find the zero-pressure thermal expansion coefficient of goethite to be alpha0 = 2.3 (+-0.6) x 10-5 K-1 over this temperature range. Our data yield zero-pressure compressional parameters: V0 = 138.75 (+- 0.02) Angstrom3, bulk modulus K0 = 140.3 (+- 3.7) GPa, pressure derivative K0' = 4.6 (+- 0.4), Gruneisen parameter gamma0 = 0.91 (+- 0.07), and Debye temperature Theta0 = 740 (+- 5) K. We identify decomposition conditions for 2alpha-FeOOH --> alpha-Fe2O3 + H2O at 1 - 8 GPa and 100-400oC, and the polymorphic transition from alpha-FeOOH (Pbnm) to epsilon-FeOOH (P21mn). The non-quenchable, high-pressure epsilon-FeOOH phase P-V data are fitted to a second-order (Birch) equation of state yielding, K0 = 158 (+- 5) GPa and V0 = 66.3 (+- 0.5) Angstrom3.

  19. Microbial Reductive Transformation of Phyllosilicate Fe(III) and U(VI) in Fluvial Subsurface Sediments

    SciTech Connect (OSTI)

    Lee, Ji-Hoon; Fredrickson, Jim K.; Kukkadapu, Ravi K.; Boyanov, Maxim I.; Kemner, Kenneth M.; Lin, Xueju; Kennedy, David W.; Bjornstad, Bruce N.; Konopka, Allan; Moore, Dean A.; Resch, Charles T.; Phillips, Jerry L.

    2012-04-14

    The microbial reduction of Fe(III) and U(VI) were investigated in shallow aquifer sediments collected from subsurface Pleistocene flood deposits near the Hanford Reach of the Columbia River in Washington State. Increases in 0.5 N HCl-extractable Fe(II) were observed in incubated sediments and 57Fe Mössbauer spectroscopy revealed that Fe(III) associated with phyllosilicates and pyroxene was reduced to Fe(II). Aqueous uranium(VI) concentrations decreased in incubated Hanford sediments with the rate and extent being greater in sediment amended with organic carbon. X-ray absorption spectroscopy of bioreduced sediments indicated that 67-77% of the U signal was U(VI), probably as an adsorbed species associated with a new or modified reactive mineral phase. Phylotypes within the Deltaproteobacteria were more common in Hanford sediments incubated with U(VI) than without and in U(VI)-free incubations, members of the Clostridiales were dominant with sulfate-reducing phylotypes more common in the sulfate-amended sediments. These results demonstrate the potential for anaerobic reduction phyllosilicate Fe(III) and sulfate in Hanford unconfined aquifer sediments and biotransformations involving reduction and adsorption leading to decreased aqueous U concentrations.

  20. An XMM-Newton view of FeK{\\alpha} in HMXBs

    E-Print Network [OSTI]

    Giménez-García, A; Eikmann, W; Martínez-Núñez, S; Oskinova, L M; Rodes-Roca, J J; Bernabéu, G

    2015-01-01

    We present a comprehensive analysis of the whole sample of available XMM-Newton observations of High Mass X-ray Binaries (HMXBs) until August, 2013, focusing on the FeK{\\alpha} emission line. This line is a key tool to better understand the physical properties of the material surrounding the X-ray source within a few stellar radii (the circumstellar medium). We have collected observations from 46 HMXBs, detecting FeK{\\alpha} in 21 of them. We have used the standard classification of HMXBs to divide the sample in different groups. We find that: (1) FeK{\\alpha} is centred at a mean value of 6.42 keV. Considering the instrumental and fits uncertainties, this value is compatible with ionization states lower than FeXVIII. (2) The flux of the continuum is well correlated with the flux of the line, as expected. Eclipse observations show that the Fe fluorescence emission comes from an extended region surrounding the X-ray source. (3) FeK{\\alpha} is narrow (width lower than 0.15keV), reflecting that the reprocessing m...

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

    SciTech Connect (OSTI)

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

    2014-05-07

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

  2. Interplay between out-of-plane anisotropic L1{sub 1}-type CoPt and in-plane anisotropic NiFe layers in CoPt/NiFe exchange springs

    SciTech Connect (OSTI)

    Saravanan, P.; Hsu, Jen-Hwa Tsai, C. L.; Tsai, C. Y.; Lin, Y. H.; Kuo, C. Y.; Wu, J.-C.; Lee, C.-M.

    2014-06-28

    Films of L1{sub 1}-type CoPt/NiFe exchange springs were grown with different NiFe (Permalloy) layer thickness (t{sub NiFe}?=?0–10?nm). X-ray diffraction analysis reveals that the characteristic peak position of NiFe(111) is not affected by the CoPt-layer—confirming the absence of any inter-diffusion between the CoPt and NiFe layers. Magnetic studies indicate that the magnetization orientation of NiFe layer can be tuned through varying t{sub NiFe} and the perpendicular magnetic anisotropy of L1{sub 1}-type CoPt/NiFe films cannot sustain for t{sub NiFe} larger than 3.0?nm due to the existence of exchange interaction at the interface of L1{sub 1}-CoPt and NiFe layers. Magnetic force microscopy analysis on the as-grown samples shows the changes in morphology from maze-like domains with good contrast to hazy domains when t{sub NiFe}???3.0?nm. The three-dimensional micro-magnetic simulation results demonstrate that the magnetization orientation in NiFe layer is not uniform, which continuously increases from the interface to the top of NiFe layer. Furthermore, the tilt angle of the topmost NiFe layers can be changed over a very wide range from a small number to about 75° by varying t{sub NiFe} from 1 to 10?nm. It is worth noting that there is an abrupt change in the magnetization direction at the interface, for all the t{sub NiFe} investigated. The results of present study demonstrate that the tunable tilted exchange springs can be realized with L1{sub 1}-type CoPt/NiFe bilayers for future applications in three-axis magnetic sensors or advanced spintronic devices demanding inclined magnetic anisotropy.

  3. Tailoring Fe-Base Alloys for Intermediate Temperature SOFC Interconnect Application

    SciTech Connect (OSTI)

    J.H. Zhu; M.P. Brady; H.U. Anderson

    2007-12-31

    This report summarized the research efforts and major conclusions for our SECA Phase I and II project focused on Cr-free or low Cr Fe-Ni based alloy development for intermediate temperature solid oxide fuel cell (SOFC) interconnect application. Electrical conductivity measurement on bulk (Fe,Ni){sub 3}O{sub 4} coupons indicated that this spinel phase possessed a higher electrical conductivity than Cr{sub 1.5}Mn{sub 1.5}O{sub 4} spinel and Cr{sub 2}O{sub 3}, which was consistent with the low area specific resistance (ASR) of the oxide scale formed on these Fe-Ni based alloys. For Cr-free Fe-Ni binary alloys, although the increase in Ni content in the alloys improved the oxidation resistance, and the Fe-Ni binary alloys exhibited adequate CTE and oxide scale ASR, their oxidation resistance needs to be further improved. Systematic alloy design efforts have led to the identification of one low-Cr (6wt.%) Fe-Ni-Co based alloy which formed a protective, electrically-conductive Cr{sub 2}O{sub 3} inner layer underneath a Cr-free, highly conductive spinel outer layer. This low-Cr, Fe-Ni-Co alloy has demonstrated a good CTE match with other cell components; high oxidation resistance comparable to that of Crofer; low oxide scale ASR with the formation of electrically-insulating phases in the oxide scale; no scale spallation during thermal cycling; adequate compatibility with cathode materials; and comparable mechanical properties with Crofer. The existence of the Cr-free (Fe,Co,Ni){sub 3}O{sub 4} outer layer effectively reduced the Cr evaporation and in transpiration testing resulted in a 6-fold decrease in Cr evaporation as compared to a state-of-the-art ferritic interconnect alloy. In-cell testing using an anode supported cell with a configuration of Alloy/Pt/LSM/YSZ/Ni+YSZ indicates that the formation of the Cr-free spinel layer via thermal oxidation was effective in blocking the Cr migration and thus improving the cell performance stability. Electroplating of the Fe-Ni-Co alloys as precursor to synthesize a protective spinel layer on commercial ferritic steels has been initiated to facilitate the utilization of the Cr-free spinel as a surface seal to block Cr evaporation. It is suggested that low-cost Fe-Ni-Co alloy coating on commercial ferritic steels might be the best approach to completely eliminate the Cr poisoning problem in SOFC stacks, while maintaining the relatively low overall cost of the interconnect component.

  4. Proceedings of the joint contractors meeting: FE/EE Advanced Turbine Systems conference FE fuel cells and coal-fired heat engines conference

    SciTech Connect (OSTI)

    Geiling, D.W.

    1993-08-01

    The joint contractors meeting: FE/EE Advanced Turbine Systems conference FEE fuel cells and coal-fired heat engines conference; was sponsored by the US Department of Energy Office of Fossil Energy and held at the Morgantown Energy Technology Center, P.O. Box 880, Morgantown, West Virginia 26507-0880, August 3--5, 1993. Individual papers have been entered separately.

  5. Direct Spectroscopic Observation of Fe(III)-Phenolate Complex Formed From the Reaction of Benzene With Peroxide Species on Fe/ZSM-5 At Room Temperature

    E-Print Network [OSTI]

    Li, Weixue

    Direct Spectroscopic Observation of Fe(III)-Phenolate Complex Formed From the Reaction of BenzeneVed: March 20, 2008 The reaction of benzene with the active oxygen species was studied by UV-visible diffuse as a precursor for phenol resins, fibers, dyestuffs, and medicine. The direct oxidation of benzene to phenol

  6. Nuclear resonance vibrational spectroscopy reveals the FeS cluster composition and active site vibrational properties of an O2-tolerant NAD+-reducing [NiFe] hydrogenase

    SciTech Connect (OSTI)

    Lauterbach, Lars; Wang, Hongxin; Horch, Marius; Gee, Leland B.; Yoda, Yoshitaka; Tanaka, Yoshihito; Zebger, Ingo; Lenz, Oliver; Cramer, Stephen P.

    2014-10-30

    Hydrogenases are complex metalloenzymes that catalyze the reversible splitting of molecular hydrogen into protons and electrons essentially without overpotential. The NAD+-reducing soluble hydrogenase (SH) from Ralstonia eutropha is capable of H2 conversion even in the presence of usually toxic dioxygen. The molecular details of the underlying reactions are largely unknown, mainly because of limited knowledge of the structure and function of the various metal cofactors present in the enzyme. Here, all iron-containing cofactors of the SH were investigated by 57Fe specific nuclear resonance vibrational spectroscopy (NRVS). Our data provide experimental evidence for one [2Fe2S] center and four [4Fe4S] clusters, which is consistent with the amino acid sequence composition. Only the [2Fe2S] cluster and one of the four [4Fe4S] clusters were reduced upon incubation of the SH with NADH. This finding explains the discrepancy between the large number of FeS clusters and the small amount of FeS cluster-related signals as detected by electron paramagnetic resonance spectroscopic analysis of several NAD+-reducing hydrogenases. For the first time, Fe–CO and Fe–CN modes derived from the [NiFe] active site could be distinguished by NRVS through selective 13C labeling of the CO ligand. This strategy also revealed the molecular coordinates that dominate the individual Fe–CO modes. The present approach explores the complex vibrational signature of the Fe–S clusters and the hydrogenase active site, thereby showing that NRVS represents a powerful tool for the elucidation of complex biocatalysts containing multiple cofactors.

  7. NEW Fe I LEVEL ENERGIES AND LINE IDENTIFICATIONS FROM STELLAR SPECTRA

    SciTech Connect (OSTI)

    Peterson, Ruth C. [SETI Institute and Astrophysical Advances, 607 Marion Place, Palo Alto, CA 94301 (United States); Kurucz, Robert L., E-mail: peterson@ucolick.org [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2015-01-01

    The spectrum of the Fe I atom is critical to many areas of astrophysics and beyond. Measurements of the energies of its high-lying levels remain woefully incomplete, however, despite extensive laboratory and solar analysis. In this work, we use high-resolution archival absorption-line ultraviolet and optical spectra of stars whose warm temperatures favor moderate Fe I excitation. We derive the energy for a particular upper level in Kurucz's semiempirical calculations by adopting a trial value that yields the same wavelength for a given line predicted to be about as strong as that of a strong unidentified spectral line observed in the stellar spectra, then checking the new wavelengths of other strong predicted transitions that share the same upper level for coincidence with other strong observed unidentified lines. To date, this analysis has provided the upper energies of 66 Fe I levels. Many new energy levels are higher than those accessible to laboratory experiments; several exceed the Fe I ionization energy. These levels provide new identifications for over 2000 potentially detectable lines. Almost all of the new levels of odd parity include UV lines that were detected but unclassified in laboratory Fe I absorption spectra, providing an external check on the energy values. We motivate and present the procedure, provide the resulting new energy levels and their uncertainties, list all the potentially detectable UV and optical new Fe I line identifications and their gf values, point out new lines of astrophysical interest, and discuss the prospects for additional Fe I energy level determinations.

  8. Observation of Precipitation Evolution in Fe-Ni-Mn-Ti-Al Maraging Steel using Atom Probe Tomography

    SciTech Connect (OSTI)

    Pereloma, E. V.; Stohr, R A; Miller, Michael K; Ringer, S. P.

    2009-01-01

    We describe the full decomposition sequence in an Fe-Ni-Mn-Ti-Al maraging steel during isothermal annealing at 550 C. Following significant pre-precipitation clustering reactions within the supersaturated martensitic solid solution, (Ni,Fe){sub 3}Ti and (Ni,Fe){sub 3}(Al,Mn) precipitates eventually form after isothermal aging for {approx}60 seconds. The morphology of the (Ni,Fe){sub 3}Ti particles changes gradually during aging from predominantly plate-like to rod-like, and, importantly, Mn and Al were observed to segregate to these precipitate/matrix interfaces. The (Ni,Fe){sub 3}(Al,Mn) precipitates occurred at two main locations: uniformly within the matrix and at the periphery of the (Ni,Fe){sub 3}Ti particles. We relate this latter mode of precipitation to the Mn-Al segregation.

  9. Acetic Acid (H3COOH): GaAs; Pb; Ti Hydrochloric Acid (HCl): Al; Cr; Cu; Fe2O3; Ga; GaAs; GaN; In; Fe; Pb; Ni; NiO, Ni2O3; Sn;

    E-Print Network [OSTI]

    Garmestani, Hamid

    ferrocyanide (s) KMnO4 : potassium permanganate (s) FeCl3 : ferric chloride (s) NH4SO5 : ammonium persulfate (s

  10. Scanning Tunneling Microscopy and Theoretical Study of Water Adsorption on Fe3O4: Implications for Catalysis

    SciTech Connect (OSTI)

    Rim, Kwang T.; Eom, Daejin; Chan, Siu-Wai; Flytzani-Stephanopoulos, Maria; Flynn, George; Wen, Xiaodong; Batista, Enrique R.

    2012-10-23

    The reduced surface of a natural Hematite single crystal a-Fe2O3(0001) sample has multiple surface domains with di!erent terminations, Fe2O3(0001), FeO(111), and Fe3O4(111). The adsorption of water on this surface was investigated via Scanning Tunneling Microscopy (STM) and first-principle theoretical simulations. Water species are observed only on the Fe-terminated Fe3O4(111) surface at temperatures up to 235 K. Between 235 and 245 K we observed a change in the surface species from intact water molecules and hydroxyl groups bound to the surface to only hydroxyl groups atop the surface terminating FeIII cations. This indicates a low energy barrier for water dissociation on the surface of Fe3O4 that is supported by our theoretical computations. Our first principles simulations con"rm the identity of the surface species proposed from the STM images, finding that the most stable state of a water molecule is the dissociated one (OH + H), with OH atop surface terminating FeIII sites and H atop under-coordinated oxygen sites. Attempts to simulate reaction of the surface OH with coadsorbed CO fail because the only binding sites for CO are the surface FeIII atoms, which are blocked by the much more strongly bound OH. In order to promote this reaction we simulated a surface decorated with gold atoms. The Au adatoms are found to cap the under-coordinated oxygen sites and dosed CO is found to bind to the Au adatom. This newly created binding site for CO not only allows for coexistence of CO and OH on the surface of Fe3O4 but also provides colocation between the two species. These two factors are likely promoters of catalytic activity on Au/Fe3O4(111) surfaces.

  11. Behavior of iron in (Mg,Fe)SiO3 post-perovskite assemblages at Mbar pressures

    E-Print Network [OSTI]

    Jackson, Jennifer M.

    Behavior of iron in (Mg,Fe)SiO3 post-perovskite assemblages at Mbar pressures Jennifer M. Jackson,1- perovskite (PPv) structured (57 Fe,Mg)SiO3 has been measured in-situ at 1.12 and 1.19 Mbar at room. Sturhahn, O. Tschauner, M. Lerche, and Y. Fei (2009), Behavior of iron in (Mg,Fe)SiO3 post-perovskite

  12. Reduction And Immobilization Of Hexavalent Chromium By Microbially Reduced Fe-bearing Clay Minerals

    SciTech Connect (OSTI)

    Bishop, Michael E.; Glasser, Paul; Dong, Hailiang; Arey, Bruce W.; Kovarik, Libor

    2014-05-15

    Hexavalent chromium (Cr6+) is a major contaminant in the environment. As a redox-sensitive element, the fate and toxicity of chromium is controlled by reduction-oxidation (redox) reactions. Previous research has shown the ability of structural Fe(II) in naturally present and chemically reduced clay minerals to reduce Cr6+ to Cr(III) as a way of immobilization and detoxification. However, it is still poorly known whether or not structural Fe(II) in biologically reduced clay minerals exhibits a similar reactivity and if so, what the kinetics and mechanisms of Cr6+ reduction are. The objective of this study was to determine the kinetics and possible mechanisms of Cr6+ reduction by structural Fe(II) in microbially reduced clay minerals and the nature of reduced Cr(III). Structural Fe(III) in nontronite (NAu-2), montmorillonite (SWy-2), chlorite (CCa-2), and clay-rich sediments from the Ringold Formation of the Hanford site of Washington State, USA was first bioreduced to Fe(II) by an iron-reducing bacterium Geobacter sulfurreducens with acetate as the sole electron donor and anthraquinone-2,6-disulfate (AQDS) as electron shuttle in synthetic groundwater (pH 7). Biogenic Fe(II) was then used to reduce aqueous Cr6+ at three different temperatures, 10°, 20°, and 30°C, in order to determine the temperature dependence of the redox reaction between Cr6+ and clay-Fe(II). The results showed that nontronite and montmorillonite were most effective in reducing aqueous Cr6+ at all three temperatures. In contrast, most Fe(II) in chlorite was not reactive towards Cr6+ reduction at 10°C, though at 30°C there was some reduction. For all the clay minerals, the ratio of total Fe(II) oxidized to Cr6+ reduced was close to the expected stoichiometric value of 3. Characterization of the Cr-clay reaction product with scanning electron microscopy with focused ion beam and transmission electron microscopy with electron energy loss spectroscopy revealed that reduced chromium was possibly in the form of sub-nanometer Cr2O3 in association with residual clay minerals as micro-aggregates. This textural association was expected to minimize the chance of Cr(III) reoxidation upon exposure to oxidants. These results are important for our understanding of how various clay minerals may be used to reductively immobilize the heavy metal contaminant Cr in the environment.

  13. Stress-induced large Curie temperature enhancement in Fe(sub 64)Ni(sub 36) Invar alloy.

    SciTech Connect (OSTI)

    Gorria, P.; Martinez-Blanco, D.; Perez, M. J.; Blanco, J. A.; Hernando, A.; Laguna-Marco, M. A.; Haskel, D.; Souza-Neto, N. M.; Xmith, R. I.; Marshall, W. G.; Garbarino, G.; Mezouar, M.; Fernandez-Martinez, A.; Chaboy, J.; Fernandez Barquin, L.; Rodriguez Castrillon, J. A.; Moldovan, M.; Garcia Alonso, J. I.; Zhang, J.; Llobet, A.; Jiang, J. S.; Univ. de Oviedo; Inst. de Magnetismo Aplicado; ISIS Facility; ESRF; Univ.Grenoble and CNRS; CSIC-Univ. de Zaragoza; Univ. de Cantabria; LANL

    2009-01-01

    We have succeeded in increasing up to 150 K the Curie temperature in the Fe{sub 64}N{sub 36}6 invar alloy by means of a severe mechanical treatment followed by a heating up to 1073 K. The invar behavior is still present as revealed by the combination of magnetic measurements with neutron and x-ray techniques under extreme conditions, such as high temperature and high pressure. The proposed explanation is based in a selective induced microstrain around the Fe atoms, which causes a slight increase in the Fe-Fe interatomic distances, thus reinforcing ferromagnetic interactions due to the strong magnetoelastic coupling in these invar compounds.

  14. Asymmetric spin-wave dispersion due to Dzyaloshinskii-Moriya interaction in an ultrathin Pt/CoFeB film

    SciTech Connect (OSTI)

    Di, Kai; Zhang, Vanessa Li; Lim, Hock Siah; Ng, Ser Choon; Kuok, Meng Hau; Qiu, Xuepeng; Yang, Hyunsoo

    2015-02-02

    Employing Brillouin spectroscopy, strong interfacial Dzyaloshinskii-Moriya interactions have been observed in an ultrathin Pt/CoFeB film. Our micromagnetic simulations show that spin-wave nonreciprocity due to asymmetric surface pinning is insignificant for the 0.8?nm-thick CoFeB film studied. The observed high asymmetry of the monotonic spin wave dispersion relation is thus ascribed to strong Dzyaloshinskii-Moriya interactions present at the Pt/CoFeB interface. Our findings should further enhance the significance of CoFeB as an important material for magnonic and spintronic applications.

  15. Preparation and structural characterization of FeCo epitaxial thin films on insulating single-crystal substrates

    SciTech Connect (OSTI)

    Nishiyama, Tsutomu; Ohtake, Mitsuru; Futamoto, Masaaki; Kirino, Fumiyoshi

    2010-05-15

    FeCo epitaxial films were prepared on MgO(111), SrTiO{sub 3}(111), and Al{sub 2}O{sub 3}(0001) single-crystal substrates by ultrahigh vacuum molecular beam epitaxy. The effects of insulating substrate material on the film growth process and the structures were investigated. FeCo(110){sub bcc} films grow on MgO substrates with two type domains, Nishiyama-Wassermann (NW) and Kurdjumov-Sachs (KS) relationships. On the contrary, FeCo films grown on SrTiO{sub 3} and Al{sub 2}O{sub 3} substrates include FeCo(111){sub bcc} crystal in addition to the FeCo(110){sub bcc} crystals with NW and KS relationships. The FeCo(111){sub bcc} crystal consists of two type domains whose orientations are rotated around the film normal by 180 deg. each other. The out-of-plane and the in-plane lattice spacings of FeCo(110){sub bcc} and FeCo(111){sub bcc} crystals formed on the insulating substrates are in agreement with those of the bulk Fe{sub 50}Co{sub 50} (at. %) crystal with small errors ranging between +0.2% and +0.4%, showing that the strains in the epitaxial films are very small.

  16. Understanding the solidification and microstructure evolution during CSC-MIG welding of Fe–Cr–B-based alloy

    SciTech Connect (OSTI)

    Sorour, A.A. Chromik, R.R. Gauvin, R. Jung, I.-H. Brochu, M.

    2013-12-15

    The present is a study of the solidification and microstructure of Fe–28.2%Cr–3.8%B–1.5%Si–1.5%Mn (wt.%) alloy deposited onto a 1020 plain carbon steel substrate using the controlled short-circuit metal inert gas welding process. The as-solidified alloy was a metal matrix composite with a hypereutectic microstructure. Thermodynamic calculation based on the Scheil–Gulliver model showed that a primary (Cr,Fe){sub 2}B phase formed first during solidification, followed by an eutectic formation of the (Cr,Fe){sub 2}B phase and a body-centered cubic Fe-based solid solution matrix, which contained Cr, Mn and Si. Microstructure analysis confirmed the formation of these phases and showed that the shape of the (Cr,Fe){sub 2}B phase was irregular plate. As the welding heat input increased, the weld dilution increased and thus the volume fraction of the (Cr,Fe){sub 2}B plates decreased while other microstructural characteristics were similar. - Highlights: • We deposit Fe–Cr–B-based alloy onto plain carbon steel using the CSC-MIG process. • We model the solidification behavior using thermodynamic calculation. • As deposited alloy consists of (Cr,Fe){sub 2}B plates embedded in Fe-based matrix. • We study the effect of the welding heat input on the microstructure.

  17. ROLE OF QUARTERNARY ADDITIONS ON DISLOCATED MARTENSITE, RETAIN AUSTENITE AND MECHANICAL PROPERTIES OF Fe/Cr/C STRUCTURAL STEELS

    E-Print Network [OSTI]

    Rao, Bangaru Venkata Narasimha

    2011-01-01

    ductile fracture (dimpled rupture) above DBTT. While the Fe/4Cr/0.35C base steels exhibited excellent plane strain fracture toughness

  18. The Vertical Metallicity Gradient of the Milky Way Disk: Transitions in [a/Fe] Populations

    E-Print Network [OSTI]

    Schlesinger, Katharine J; Rockosi, Constance M; Lee, Young Sun; Beers, Timothy C; Harding, Paul; Prieto, Carlos Allende; Bird, Jonathan C; Schoenrich, Ralph; Yanny, Brian; Schneider, Donald P; Weaver, Benjamin A; Brinkmann, Jon

    2014-01-01

    Using G dwarfs from the Sloan Extension for Galactic Understanding and Exploration (SEGUE) survey, we have determined a vertical metallicity gradient over a large volume of the Milky Way's disk, and examined how this gradient varies for different [a/Fe] subsamples. This sample contains over 40,000 stars with low-resolution spectroscopy over 144 lines of sight. We employ the SEGUE Stellar Parameter Pipeline (SSPP) to obtain estimates of effective temperature, surface gravity, [Fe/H], and [a/Fe] for each star and extract multiple volume-complete subsamples of approximately 1000 stars each. Based on the survey's consistent target-selection algorithm, we adjust each subsample to determine an unbiased picture of the disk in [Fe/H] and [a/Fe]; consequently, each individual star represents the properties of many. The SEGUE sample allows us to constrain the vertical metallicity gradient for a large number of stars over a significant volume of the disk, between ~0.3 and 1.6 kpc from the Galactic plane, and examine the...

  19. Fe K Line Profile in Low-redshift Quasars: Average Shape and Eddington Ratio Dependence

    E-Print Network [OSTI]

    Hirohiko Inoue; Yuichi Terashima; Luis C. Ho

    2007-03-14

    We analyze X-ray spectra of 43 Palomar-Green quasars observed with {\\it XMM-Newton} in order to investigate their mean Fe K line profile and its dependence on physical properties. The continuum spectra of 39 objects are well reproduced by a model consisting of a power law and a blackbody modified by Galactic absorption. The spectra of the remaining four objects require an additional power-law component absorbed with a column density of $\\sim 10^{23} {\\rm cm}^{-2}$. We fit the entire sample simultaneously to derive average Fe line parameters by assuming a common Fe line shape. The Fe line is relatively narrow ($\\sigma=0.36$ keV), with a center energy of 6.48 keV and a mean equivalent width (EW) of 248 eV. By combining black hole masses estimated from the virial method and bolometric luminosities derived from full spectral energy distributions, we examine the dependence of the Fe K line profile on Eddington ratio. As the Eddington ratio increases, the line becomes systematically stronger (EW = 130 to 280 eV), broader ($\\sigma=0.1$ to 0.7 keV), and peaks at higher energies (6.4 to 6.8 keV). This result suggests that the accretion rate onto the black hole directly influences the geometrical structure and ionization state of the accretion disk.

  20. Superparamagnetic behavior of Fe-doped SnO{sub 2} nanoparticles

    SciTech Connect (OSTI)

    Hachisu, M.; Onuma, K.; Kondo, T.; Miike, K.; Miyasaka, T.; Mori, K.; Ichiyanagi, Y.

    2014-02-20

    SnO{sub 2} is an n-type semiconductor with a wide band gap of 3.62 eV, and SnO{sub 2} nanoparticles doped with magnetic ions are expected to realized new diluted magnetic semiconductors (DMSs). Realizing ferromagnetism at room temperature is important for spintronics device applications, and it is interesting that the magnetic properties of these DMS systems can be varied significantly by modifying the preparation methods or conditions. In this study, the magnetic properties of Fe-doped (3% and 5%) SnO{sub 2} nanoparticles, prepared using our novel chemical preparation method and encapsulated in amorphous SiO{sub 2}, were investigated. The particle size (1.8–16.9 nm) and crystal phase were controlled by the annealing temperature. X-ray diffraction confirmed a rutile SnO{sub 2} single-phase structure for samples annealed at 1073–1373 K, and the composition was confirmed using X-ray fluorescence analysis. SQUID magnetometer measurements revealed superparamagnetic behavior of the 5%-Fe-doped sample at room temperature, although SnO{sub 2} is known to be diamagnetic. Magnetization curves at 5 K indicated that the 3%-Fe-doped has a larger magnetization than that of the 5%-Fe-doped sample. We conclude that the magnetization of the 5%-Fe-doped sample decreased at 5 K due to the superexchange interaction between the antiferromagnetic coupling in the nanoparticle system.

  1. Flux growth and magnetic properties of FeVO{sub 4} single crystals

    SciTech Connect (OSTI)

    He Zhangzhen Yamaura, Jun-Ichi; Ueda, Yutaka

    2008-09-15

    FeVO{sub 4} (I) single crystals are grown by the flux method using V{sub 2}O{sub 5} as the self-flux. The grown crystals exhibit a characteristic morphology with natural facets. The quality of the crystals is confirmed by X-ray diffraction and EPMA techniques. Magnetic properties are investigated by means of magnetic susceptibility, magnetization, and heat capacity measurements. Two magnetic phase transitions are observed at {approx}13 and {approx}20 K. Such unusual magnetic behaviors are suggested to originate from two different Fe ligand environments of octahedral FeO{sub 6} and trigonal bipyramidal FeO{sub 5} in a six-column doubly bent chain. - Graphical abstract: FeVO{sub 4} (I) single crystals are grown by the flux method using V{sub 2}O{sub 5} as the self-flux. Magnetic properties are investigated by means of magnetic susceptibility, magnetization, and heat capacity measurements, showing two magnetic phase transitions at {approx}13 and {approx}20 K.

  2. IMPLICATIONS OF INFALLING Fe II-EMITTING CLOUDS IN ACTIVE GALACTIC NUCLEI: ANISOTROPIC PROPERTIES

    SciTech Connect (OSTI)

    Ferland, Gary J. [Department of Physics, University of Kentucky, Lexington, KY 40506 (United States); Hu Chen; Wang Jianmin [Key Laboratory for Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Baldwin, Jack A. [Department of Physics and Astronomy, Michigan State University, Lansing, MI (United States); Porter, Ryan L. [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States); Van Hoof, Peter A. M. [Royal Observatory of Belgium, Ringlaan 3, 1180 Brussels (Belgium); Williams, R. J. R. [AWE plc, Aldermaston, Reading RG7 4PR (United Kingdom)

    2009-12-10

    We investigate consequences of the discovery that Fe II emission in quasars, one of the spectroscopic signatures of 'Eigenvector 1', may originate in infalling clouds. Eigenvector 1 correlates with the Eddington ratio L/L {sub Edd} so that Fe II/Hbeta increases as L/L {sub Edd} increases. We show that the 'force multiplier', the ratio of gas opacity to electron scattering opacity, is approx10{sup 3}-10{sup 4} in Fe II-emitting gas. Such gas would be accelerated away from the central object if the radiation force is able to act on the entire cloud. As had previously been deduced, infall requires that the clouds have large column densities so that a substantial amount of shielded gas is present. The critical column density required for infall to occur depends on L/L {sub Edd}, establishing a link between Eigenvector 1 and the Fe II/Hbeta ratio. We see predominantly the shielded face of the infalling clouds rather than the symmetric distribution of emitters that has been assumed. The Fe II spectrum emitted by the shielded face is in good agreement with observations thus solving several long-standing mysteries in quasar emission lines.

  3. Effects of temperature and pressure on phonons in FeSi1–xAlx

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

    Delaire, O.; Al-Qasir, I. I.; Ma, J.; dos Santos, A. M.; Sales, B. C.; Mauger, L.; Stone, M. B.; Abernathy, D. L.; Xiao, Y.; Somayazulu, M.

    2013-05-31

    The effects of temperature and pressure on phonons in B20 compounds FeSi1–xAlx were measured using inelastic neutron scattering and nuclear-resonant inelastic x-ray scattering. The effect of hole doping through Al substitution is compared to results of alloying with Co (electron doping) in Fe??xCoxSi. While the temperature dependence of phonons in FeSi is highly anomalous, doping with either type of carriers leads to a recovery of the normal quasiharmonic behavior. Density functional theory (DFT) computations of the electronic band structure and phonons were performed. The anomaly in the temperature dependence of the phonons in undoped FeSi was related to the narrowmore »band gap, and its sensitivity to the effect of thermal disordering by phonons. On the other hand, the pressure dependence of phonons at room temperature in undoped FeSi follows the quasiharmonic behavior and is well reproduced by the DFT calculations.« less

  4. On Deep-Ocean $^{60}Fe$ as a Fossil of a Near-Earth Supernova

    E-Print Network [OSTI]

    Fields, B D; Fields, Brian D.; Ellis, John

    1999-01-01

    Live $^{60}$Fe has recently been reported in a deep-ocean ferromanganese crust. Analysis of the isotopic ratios in the sample suggests that the measured $^{60}$Fe abundance exceeds the levels generated by terrestrial and cosmogenic sources, and it has been proposed that the excess of $^{60}$Fe is a signature of a supernova that exploded near the earth several Myr ago. In this paper, we consider the possible background sources, and confirm that the measured $^{60}$Fe is significantly higher than all known backgrounds, in contrast with the reported abundance of live $^{53}$Mn. We discuss scenarios in which the data are consistent with a supernova event at a distance $D \\sim 30$ pc and an epoch $t_{\\rm SN} \\sim 5$ Myr ago. We propose tests that could confirm or refute the interpretation of the $^{60}$Fe discovery, including searches for $^{10}$Be, $^{129}$I and $^{146}$Sm. Such a nearby supernova event might have had some impact on the earth's biosphere, principally by enhancing the cosmic-ray flux. This might h...

  5. On Deep-Ocean Fe-60 as a Fossil of a Near-Earth Supernova

    E-Print Network [OSTI]

    Brian D. Fields; John Ellis

    1998-11-29

    Live $^{60}$Fe has recently been reported in a deep-ocean ferromanganese crust. Analysis of the isotopic ratios in the sample suggests that the measured $^{60}$Fe abundance exceeds the levels generated by terrestrial and cosmogenic sources, and it has been proposed that the excess of $^{60}$Fe is a signature of a supernova that exploded near the earth several Myr ago. In this paper, we consider the possible background sources, and confirm that the measured $^{60}$Fe is significantly higher than all known backgrounds, in contrast with the reported abundance of live $^{53}$Mn. We discuss scenarios in which the data are consistent with a supernova event at a distance $D \\sim 30$ pc and an epoch $t_{\\rm SN} \\sim 5$ Myr ago. We propose tests that could confirm or refute the interpretation of the $^{60}$Fe discovery, including searches for $^{10}$Be, $^{129}$I and $^{146}$Sm. Such a nearby supernova event might have had some impact on the earth's biosphere, principally by enhancing the cosmic-ray flux. This might have damaged the earth's ozone layer, enhancing the penetration of solar ultraviolet radiation. In this connection, we comment on the Middle Miocene and Pliocene mini-extinction events. We also speculate on the possibility of a supernova-induced "cosmic-ray winter," if cosmic rays play a significant role in seeding cloud formation.

  6. Characterization of Fe–Cr alloy metallic interconnects coated with LSMO using the aerosol deposition process

    SciTech Connect (OSTI)

    Huang, Jian-Jia [Department of Mechanical Engineering, National Central University, Jhongli, Taoyuan, Taiwan (China); Fu, Yen-Pei, E-mail: ypfu@mail.ndhu.edu.tw [Department of Materials Science and Engineering, National Dong Hwa University, Shoufeng, Hualien, Taiwan (China); Wang, Jian-Yih [Department of Materials Science and Engineering, National Dong Hwa University, Shoufeng, Hualien, Taiwan (China); Cheng, Yung-Neng [Institute of Nuclear Energy Research, Longtan, Taoyuan, Taiwan (China); Lee, Shyong [Department of Mechanical Engineering, National Central University, Jhongli, Taoyuan, Taiwan (China); Hsu, Jin-Cherng [Department of Physics, Fu Jen Catholic University, Xinzhuang, New Taipei City, Taiwan (China)

    2014-03-01

    Graphical abstract: - Highlights: • Lanthanum strontium manganite (LSMO) as the protective layer for metallic interconnects was successfully prepared by aerosol deposition method (AD). • The microstructure, electrical resistance and composition for LSMO-coated Fe–Cr alloys undergoing high temperature, long-hour oxidation were investigated. • The denser protective layer prepared by AD might effectively prohibit the growth of oxidized scale after long time running at 800 °C in air. - Abstract: A Fe–Cr alloy, used for metallic interconnects, was coated with a protective layer of lanthanum strontium manganite (LSMO) using the aerosol deposition method (AD). The effects of the LSMO protective layer, which was coated on the Fe–Cr interconnects using AD, on the area specific resistance (ASR) during high temperature oxidation and the Cr evaporation behaviors were systematically investigated in this paper. The microstructures, morphologies, and compositions of the oxidized scales that appeared on the LSMO-coated Fe–Cr alloy after annealing at 800 °C for 750 h in air were examined using SEM equipped with EDS. The EPMA mapping of the LSMO-coated Fe–Cr interconnects undergoing long term, high-temperature oxidation was used to explain the formation layers of the oxidized scale, which consists of (Mn,Cr){sub 3}O{sub 4} and Cr{sub 2}O{sub 3} layers. Moreover, the experimental results revealed that the AD process is a potential method for preparing denser protective layers with highly desirable electrical properties for metallic interconnects.

  7. Synthesis of multiferroic Er-Fe-O thin films by atomic layer and chemical vapor deposition

    SciTech Connect (OSTI)

    Mantovan, R., E-mail: roberto.mantovan@mdm.imm.cnr.it; Vangelista, S.; Wiemer, C.; Lamperti, A.; Tallarida, G. [Laboratorio MDM IMM-CNR, I-20864 Agrate Brianza (MB) (Italy); Chikoidze, E.; Dumont, Y. [GEMaC, Université de Versailles St. Quentin en Yvelines-CNRS, Versailles (France); Fanciulli, M. [Laboratorio MDM IMM-CNR, I-20864 Agrate Brianza (MB) (Italy); Dipartimento di Scienza dei Materiali, Università di Milano Bicocca, Milano (Italy)

    2014-05-07

    R-Fe-O (R?=?rare earth) compounds have recently attracted high interest as potential new multiferroic materials. Here, we report a method based on the solid-state reaction between Er{sub 2}O{sub 3} and Fe layers, respectively grown by atomic layer deposition and chemical vapor deposition, to synthesize Er-Fe-O thin films. The reaction is induced by thermal annealing and evolution of the formed phases is followed by in situ grazing incidence X-ray diffraction. Dominant ErFeO{sub 3} and ErFe{sub 2}O{sub 4} phases develop following subsequent thermal annealing processes at 850?°C in air and N{sub 2}. Structural, chemical, and morphological characterization of the layers are conducted through X-ray diffraction and reflectivity, time-of-flight secondary ion-mass spectrometry, and atomic force microscopy. Magnetic properties are evaluated by magnetic force microscopy, conversion electron Mössbauer spectroscopy, and vibrating sample magnetometer, being consistent with the presence of the phases identified by X-ray diffraction. Our results constitute a first step toward the use of cost-effective chemical methods for the synthesis of this class of multiferroic thin films.

  8. Synthesis and Characterization of PhotocatalyticTiO2-ZnFe2O4Nanoparticles

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

    Srinivasan, Sesha S.; Wade, Jeremy; Stefanakos, Elias K.

    2006-01-01

    A new coprecipitation/hydrolysis synthesis route is used to create aTiO2-ZnFe2O4nanocomposite that is directed towards extending the photoresponse ofTiO2from UV to visible wavelengths (>400?nm). The effect ofTiO2's accelerated anatase-rutile phase transformation due to the presence of the coupledZnFe2O4narrow-bandgap semiconductor is evaluated. The transformation's dependence on pH, calcinations temperature, particle size, andZnFe2O4concentration has been analyzed using XRD, SEM, and UV-visible spectrometry. The requirements for retaining the highly photoactive anatase phase present in aZnFe2O4nanocomposite are outlined. The visible-light-activated photocatalytic activity of theTiO2-ZnFe2O4nanocomposites has been compared to an AldrichTiO2reference catalyst, using a solar-simulated photoreactor formore »the degradation of phenol.« less

  9. New EUV Fe IX emission line identifications from Hinode/EIS

    E-Print Network [OSTI]

    P. R. Young

    2008-10-28

    Four Fe IX transitions in the wavelength range 188--198 A are identified for the first time in spectra from the EUV Imaging Spectrometer on board the Hinode satellite. In particular the emission line at 197.86 A is unblended and close to the peak of the EIS sensitivity curve, making it a valuable diagnostic of plasma at around 800,000 K - a critical temperature for studying the interface between the corona and transition region. Theoretical ratios amongst the four lines predicted from the CHIANTI database reveal weak sensitivity to density and temperature with observed values consistent with theory. The ratio of 197.86 relative to the 171.07 resonance line of Fe IX is found to be an excellent temperature diagnostic, independent of density, and the derived temperature in the analysed data set is log T=5.95, close to the predicted temperature of maximum ionization of Fe IX.

  10. Fabrication of Fe nanowires on yittrium-stabilized zirconia single crystal substrates by thermal CVD methods

    SciTech Connect (OSTI)

    Kawahito, A.; Yanase, T.; Endo, T.; Nagahama, T.; Shimada, T.

    2015-05-07

    Magnetic nanowires (NWs) are promising as material for use in spintronics and as the precursor of permanent magnets because they have unique properties due to their high aspect ratio. The growth of magnetic Fe whiskers was reported in the 1960s, but the diameter was not on a nanoscale level and the growth mechanism was not fully elucidated. In the present paper, we report the almost vertical growth of Fe NWs on a single crystal yttrium-stabilized zirconia (Y{sub 0.15}Zr{sub 0.85}O{sub 2}) by a thermal CVD method. The NWs show a characteristic taper part on the bottom growing from a trigonal pyramidal nucleus. The taper angle and length can be controlled by changing the growth condition in two steps, which will lead to obtaining uniformly distributed thin Fe NWs for applications.

  11. GaN/Fe core/shell nanowires for nonvolatile spintronics on Si

    SciTech Connect (OSTI)

    Gao Cunxu; Farshchi, Rouin; Roder, Claudia; Dogan, Pinar; Brandt, Oliver

    2011-06-15

    We explore the relationship between the structural and magnetic properties of GaN/Fe core/shell nanowires grown epitaxially on Si substrates. The magnetic properties are consistent with the coexistence of two magnetic contributions: a ferromagnetic response from the single-crystalline Fe particles formed at the nanowire tips, and a superparamagnetic response originating from the granular Fe clusters grown on the nanowire sidewalls, giving them a corncob-like morphology. We show that our interpretation of the origin of the magnetic behavior can be confirmed by the viscous decay of magnetic remanence in the nanowires. Ferromagnetic remanence is observed both parallel and perpendicular to the nanowire axis, making such structures appealing as high-density nonvolatile spintronic components on Si.

  12. Experimental study of the beta-delayed proton precursors /sup 33/Ar and /sup 49/Fe

    SciTech Connect (OSTI)

    XU Xiao-ji; GUO Jun-sheng; GUO Ying-xiang; ZHAO Zhi-zheng; LUO Yi-xiao

    1985-01-01

    Beta-delayed proton precursors /sup 33/Ar and /sup 49/Fe have been produced via the (/sup 12/C,3n) reaction in 65-MeV carbon bombardments of /sup 24/Mg and /sup 40/Ca, respectively. The major proton peaks are at 3.28 +- 0.07 MeV for /sup 33/Ar and 1.98 +- 0.04 MeV for /sup 49/Fe. The corresponding cross section for /sup 33/Ar is 0.40 +- 0.08 ..mu..b, and for /sup 49/Fe 0.70 +- 0.14 ..mu..b. The half-life of /sup 33/Ar was determined to be 167 +- 24 ms.

  13. Modification of structure and magnetic anisotropy of epitaxial CoFe?O? films by hydrogen reduction

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

    Chen, Aiping; Poudyal, Narayan; Xiong, Jie; Liu, J. Ping; Jia, Quanxi

    2015-03-16

    Heteroepitaxial CoFe?O? (CFO) thin films with different thicknesses were deposited on MgO (001) substrates. The as-deposited CFO films show a clear switching of magnetic anisotropy with increasing film thickness. The thinner films (more »films are textured out-of-plane and aligned in-plane, owing to lattice matching between CoFe? and MgO substrate. TEM results indicate that as-deposited films are continuous while the annealed films exhibit a nanopore mushroom structure. The magnetic anisotropy of CoFe? films is dominated by the shape effect. The results demonstrate that hydrogen reduction can be effectively used to modify microstructures and physical properties of complex metal oxide materials.« less

  14. Proceedings of the AD HOC Workshop on Ceramics for Li/FeS{sub 2} batteries

    SciTech Connect (OSTI)

    Not Available

    1993-12-31

    Representatives from industry, the U.S. Advanced Battery Consortium (USABC), DOE, national laboratories, and other govt agencies met to develop recommendations and actions for accelerating the development of ceramic components critical to the successful introduction of the Li/FeS{sub 2} bipolar battery for electric vehicles. Most of the workshop is devoted to electrode materials, bipolar designs, separators, and bipolar plates. The bulk of this document is viewographs and is divided into: ceramics, USABC overview, SAFT`s Li/FeS{sub 2} USABC program, bipolar Li/FeS{sub 2} component development, design requirements for bipolar plates, separator design requirements, compatibility of ceramic insulators with lithium, characterization of MgO for use in separators, resistivity measurements of separators, sintered AlN separators for LiMS batteries, etc.

  15. Engineering Gilbert damping by dilute Gd doping in soft magnetic Fe thin films

    SciTech Connect (OSTI)

    Zhang, W. Jiang, S.; Sun, L.; Wang, Y. K.; Zhai, Y.; Wong, P. K. J.; Wang, K.; Jong, M. P. de; Wiel, W. G. van der; Laan, G. van der

    2014-05-07

    By analyzing the ferromagnetic resonance linewidth, we show that the Gilbert damping constant in soft magnetic Fe thin films can be enhanced by ?6 times with Gd doping of up to 20%. At the same time, the magnetic easy axis remains in the film plane while the coercivity is strongly reduced after Gd inclusion. X-ray magnetic circular dichroism measurements reveal a strong increase in the orbital-to-spin moment ratio of Fe with increasing Gd concentration, in full agreement with the increase in the Gilbert damping obtained for these thin films. Combined with x-ray diffraction and vibrating sample magnetometry, the results demonstrate that the FeGd thin films with dilute Gd doping of up to 20% are promising candidates for spin-transfer-torque applications in soft magnetic devices, in which an enhanced damping is required.

  16. A Ni-Fe Layered Double Hydroxide-Carbon Nanotube Complex for Water Oxidation

    E-Print Network [OSTI]

    Gong, Ming; Wang, Hailiang; Liang, Yongye; Wu, Justin Zachary; Zhou, Jigang; Wang, Jian; Regier, Tom; Wei, Fei; Dai, Hongjie

    2013-01-01

    Highly active, durable and cost-effective electrocatalysts for water oxidation to evolve oxygen gas hold a key to a range of renewable energy solutions including water splitting and rechargeable metal-air batteries. Here, we report the synthesis of ultrathin nickel iron layered double hydroxide nanoplates on mildly oxidized multi-walled carbon nanotubes. Incorporation of Fe into the nickel hydroxide induced the formation of NiFe-layered double hydroxide. The nanoplates were covalently attached to a network of nanotubes, affording excellent electrical wiring to the nanoplates. The ultra-thin Ni-Fe layered double hydroxide nanoplates/carbon nanotube complex was found to exhibit unusually high electro-catalytic activity and stability for oxygen evolution and outperformed commercial precious metal Ir catalysts.

  17. EBSD study on crystallographic texture and microstructure development of cold-rolled FePd alloy

    SciTech Connect (OSTI)

    Lin, Hung-Pin; Ng, Tin-San [Department of Materials Science and Engineering, National Cheng-Kung University, No. 1, University Road, Tainan 701, Taiwan (China); Kuo, Jui-Chao, E-mail: jckuo@mail.ncku.edu.tw [Department of Materials Science and Engineering, National Cheng-Kung University, No. 1, University Road, Tainan 701, Taiwan (China); Chen, Yen-Chun [Department of Materials Science and Engineering, National Cheng-Kung University, No. 1, University Road, Tainan 701, Taiwan (China); Chen, Chun-Liang [Department of Materials Science and Engineering, I-Shou University, No. 1 Sec. 1 Syuecheng Road, Kaohsiung 840, Taiwan (China); Ding, Shi-Xuan [Department of Materials and Optoelectronic Science, National Sun Yat-Sen University, No. 70, Lienhai Road, Kaohsiung 804, Taiwan (China); Research Center for Physical Properties and Microstructure of Metals, National Sun Yat-Sen University, No. 70, Lienhai Road, Kaohsiung 804, Taiwan (China)

    2014-07-01

    The crystallographic texture and microstructure of FePd alloy after cold-rolling deformation were investigated using electron backscatter diffraction. The major orientations of twin copper and copper after 50% thickness reduction were observed in face-centered cubic-disordered FePd alloy, whereas the main orientation was obtained from brass type after 90% cold rolling. Increase in cold rolling resulted in the change of preferred orientation from copper to brass. Decrease in orientation intensity of copper also increased that of Goss and brass. - Highlights: • The evolution of texture and microstructure in FePd alloy was investigated after cold rolling using EBSD. • Increasing in reduction leads to the change of texture from Copper-type to Brass-type. • The reduction of Copper orientation results in increasing in Goss and Brass orientations.

  18. Tailoring of a metastable material: alfa-FeSi2 thin film

    SciTech Connect (OSTI)

    Cao, Guixin; Singh, David J; Zhang, Xiaoguang; Samolyuk, German D; Qiao, Liang; Parish, Chad M; Ke, Jin; Zhang, Yanwen; Guo, Hangwen; Tang, Siwei; Wang, Wenbin; Yi, Jieyu; Cantoni, Claudia; Siemons, Wolter; Payzant, E Andrew; Biegalski, Michael D; Ward, Thomas Zac; Sales, Brian C; Mandrus, D.; Stocks, George Malcolm; Gai, Zheng

    2015-01-01

    The epitaxially stabilized metallic -FeSi2 thin films on Si(001) were grown using pulsed laser deposition. While the bulk material of -FeSi2 is a high temperature metastable phase and nonmagnetic, the thin film is stabilized at room temperature and shows unusual electronic transport and magnetic properties due to strain modification. The transport renders two different conducting states with a strong crossover at 50 K accompanied by an onset of ferromagnetism as well as a substantial magnetocaloric effect and magnetoresistance. These experimental results are discussed in terms of the unusual electronic structure of -FeSi2 obtained within density functional calculations and Boltzmann transport calculations with and without strain. Our findings provide an example of a tailored material with interesting physics properties for practical applications.

  19. Study of 57 Fe Mössbauer effect in RFe2Zn20 ( R = Lu, Yb, Gd)

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

    Bud’ko, Sergey L.; Kong, Tai; Ma, Xiaoming; Canfield, Paul C.

    2015-08-04

    In this document we report measurements of 57Fe Mössbauer spectra for RFe2Zn20 (R = Lu, Yb, Gd) from ~ 4.5 K to room temperature. The obtained isomer shift values are very similar for all three compounds, their temperature dependence was analyzed within the Debye model and resulted in an estimate of the Debye temperatures of 450-500 K. The values of quadrupole splitting at room temperature change with the cubic lattice constant a in a linear fashion. For GdFe2Zn20, ferromagnetic order is seen as an appearance of a sextet in the spectra. The 57Fe site hyperfine field for T ? 0more »was evaluated to be ~ 2.4 T.« less

  20. Substitution of Ni for Fe in superconducting Fe?.??Te?.?Se?.? depresses the normal-state conductivity but not the magnetic spectral weight

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

    Wang, Jinghui; Tranquada, J. M.; Zhong, Ruidan; Li, Shichao; Gan, Yuan; Xu, Zhijun; Zhang, Cheng; Ozaki, T.; Matsuda, M.; Zhao, Yang; et al

    2015-01-05

    We have performed systematic resistivity and inelastic neutron scattering measurements on Fe?.???zNizTe?.?Se?.? samples to study the impact of Ni substitution on the transport properties and the low-energy (? 12 meV) magnetic excitations. It is found that, with increasing Ni doping, both the conductivity and superconductivity are gradually suppressed; in contrast, the low-energy magnetic spectral weight changes little. Comparing with the impact of Co and Cu substitution, we find that the effects on conductivity and superconductivity for the same degree of substitution grow systematically as the atomic number of the substituent deviates from that of Fe. The impact of the substituentsmore »as scattering centers appears to be greater than any contribution to carrier concentration. The fact that low-energy magnetic spectral weight is not reduced by increased electron scattering indicates that the existence of antiferromagnetic correlations does not depend on electronic states close to the Fermi energy.« less

  1. Substitution of Ni for Fe in superconducting Fe?.??Te?.?Se?.? depresses the normal-state conductivity but not the magnetic spectral weight

    SciTech Connect (OSTI)

    Wang, Jinghui [Nanjing Univ., Nanjing (China); Tranquada, J. M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Zhong, Ruidan [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., Stony Brook, NY (United States); Li, Shichao [Nanjing Univ., Nanjing (China); Gan, Yuan [Nanjing Univ., Nanjing (China); Xu, Zhijun [Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Zhang, Cheng [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., Stony Brook, NY (United States); Ozaki, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Matsuda, M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Zhao, Yang [National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States); Univ. of Maryland, College Park, MD (United States); Li, Qiang [Brookhaven National Lab. (BNL), Upton, NY (United States); Xu, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Gu, Genda [Brookhaven National Lab. (BNL), Upton, NY (United States); Birgeneau, R. J. [Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wen, Jinsheng [Nanjing Univ., Nanjing (China)

    2015-01-01

    We have performed systematic resistivity and inelastic neutron scattering measurements on Fe?.???zNizTe?.?Se?.? samples to study the impact of Ni substitution on the transport properties and the low-energy (? 12 meV) magnetic excitations. It is found that, with increasing Ni doping, both the conductivity and superconductivity are gradually suppressed; in contrast, the low-energy magnetic spectral weight changes little. Comparing with the impact of Co and Cu substitution, we find that the effects on conductivity and superconductivity for the same degree of substitution grow systematically as the atomic number of the substituent deviates from that of Fe. The impact of the substituents as scattering centers appears to be greater than any contribution to carrier concentration. The fact that low-energy magnetic spectral weight is not reduced by increased electron scattering indicates that the existence of antiferromagnetic correlations does not depend on electronic states close to the Fermi energy.

  2. Substitution of Ni for Fe in superconducting Fe?.??Te?.?Se?.? depresses the normal-state conductivity but not the magnetic spectral weight

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

    Wang, Jinghui [Nanjing Univ., Nanjing (China); Tranquada, J. M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Zhong, Ruidan [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., Stony Brook, NY (United States); Li, Shichao [Nanjing Univ., Nanjing (China); Gan, Yuan [Nanjing Univ., Nanjing (China); Xu, Zhijun [Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Zhang, Cheng [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., Stony Brook, NY (United States); Ozaki, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Matsuda, M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Zhao, Yang [National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States); Univ. of Maryland, College Park, MD (United States); Li, Qiang [Brookhaven National Lab. (BNL), Upton, NY (United States); Xu, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Gu, Genda [Brookhaven National Lab. (BNL), Upton, NY (United States); Birgeneau, R. J. [Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wen, Jinsheng [Nanjing Univ., Nanjing (China)

    2015-01-01

    We have performed systematic resistivity and inelastic neutron scattering measurements on Fe?.???zNizTe?.?Se?.? samples to study the impact of Ni substitution on the transport properties and the low-energy (? 12 meV) magnetic excitations. It is found that, with increasing Ni doping, both the conductivity and superconductivity are gradually suppressed; in contrast, the low-energy magnetic spectral weight changes little. Comparing with the impact of Co and Cu substitution, we find that the effects on conductivity and superconductivity for the same degree of substitution grow systematically as the atomic number of the substituent deviates from that of Fe. The impact of the substituents as scattering centers appears to be greater than any contribution to carrier concentration. The fact that low-energy magnetic spectral weight is not reduced by increased electron scattering indicates that the existence of antiferromagnetic correlations does not depend on electronic states close to the Fermi energy.

  3. Order from Chaos: (alpha)-Fe(001) Growth on GaAs(001)

    SciTech Connect (OSTI)

    Tobin, J G; Yu, S W; Morton, S A; Waddill, G D; Thompson, J D; Neal, J R; Shen, T H

    2008-02-08

    The growth of Fe upon GaAs(001) has been studied with Spin-Resolved Photoelectron Spectroscopy (SRPES), Photoelectron Spectroscopy (PES) and X-ray Magnetic Linear Dichroism (XMLD) in PES. Despite evidence of atomic level disorder such as intermixing, an over-layer with the spectroscopic signature of {alpha}-Fe(001), with a bcc real space ordering, is obtained. The results will be discussed in light of the possibility of using such films as a spin polarized source in device applications.

  4. Magnetic anisotropy engineering: Single-crystalline Fe films on ion eroded ripple surfaces

    SciTech Connect (OSTI)

    Liedke, M. O.; Koerner, M.; Lenz, K.; Grossmann, F.; Facsko, S.; Fassbender, J.

    2012-06-11

    We present a method to preselect the direction of an induced in-plane uniaxial magnetic anisotropy (UMA) in thin single-crystalline Fe films on MgO(001). Ion beam irradiation is used to modulate the MgO(001) surface with periodic ripples on the nanoscale. The ripple direction determines the orientation of the UMA, whereas the intrinsic cubic anisotropy of the Fe film is not affected. Thus, it is possible to superimpose an in-plane UMA with a precision of a few degrees - a level of control not reported so far that can be relevant for example in spintronics.

  5. Magnetic configuration dependence of magnetoresistance in a Fe-porphyrin-like carbon nanotube spintronic device

    SciTech Connect (OSTI)

    Zeng, Jing; Chen, Ke-Qiu

    2014-01-20

    By using nonequilibrium Green's functions in combination with the density functional theory, we investigate the spin-dependent transport properties in a Fe-porphyrin-like carbon nanotube spintronic device. The results show that magnetoresistance ratio is strongly dependent on the magnetic configuration of the Fe-porphyrin-like carbon nanotube. Under the application of the external magnetic field, the magnetoresistance ratio of the device can be increased from about 19% to about 1020% by tuning the magnetic configuration in the device. Our results confirm that the magnetic configuration is a key factor for obtaining a high-performance spintronic device.

  6. El monólogo como acto de fe: Estreno en Broadway de Rodolfo Usigli

    E-Print Network [OSTI]

    Layera, Ramó n

    1994-10-01

    FALL 1994 81 El monólogo como acto de fe: Estreno en Broadway de Rodolfo Usigli Ramón Layera El monólogo corto Estreno en Broadway de Rodolfo Usigli, como pieza inédita hasta hace pocos meses, representa un desafío a la crítica académica ya... circunstancias personales de su autor, se puede decir que se trata de un acto de fe en la capacidad sublimadora y redentora del arte dramático. Comenzando por el título, Usigli anuncia el carácter ficticio y metateatral del monólogo. Se trata de un estreno...

  7. Single crystal growth and characterization of ilmenite, FeTiO?, for electronic applications 

    E-Print Network [OSTI]

    Gries, Brian Leonard

    1988-01-01

    unit cell (Figure1) with the corundum structure (AI203) and is similar to the perovskite structure represented by ABoa (1, 6). This structure consists of alternating layers of Fe2+ and Ti4+ iona separated by hexagonally stacked layers of oxygen ions... as a source of raw materials and possibly as a source of semiconductor materials for a lunar base. 44 REFERENCES 1. R. K. Pandey and B. A. Baird, Single Crystal Growth and Characterization of Fe-Ti- Oxide Compounds, Proceedings of NASA Symposium...

  8. Development and quality assessments of commercial heat production of ATF FeCrAl tubes

    SciTech Connect (OSTI)

    Yamamoto, Yukinori

    2015-09-01

    Development and quality assessment of the 2nd generation ATF FeCrAl tube production with commercial manufacturers were conducted. The manufacturing partners include Sophisticated Alloys, Inc. (SAI), Butler, PA for FeCrAl alloy casting via vacuum induction melting, Oak Ridge National Laboratory (ORNL) for extrusion process to prepare the master bars/tubes to be tube-drawn, and Rhenium Alloys, Inc. (RAI), North Ridgeville, OH, for tube-drawing process. The masters bars have also been provided to Los Alamos National Laboratory (LANL) who works with Century Tubes, Inc., (CTI), San Diego, CA, as parallel tube production effort under the current program.

  9. Element-specific spin and orbital momentum dynamics of Fe/Gdmultilayers

    SciTech Connect (OSTI)

    Bartelt, A.F.; Comin, A.; Feng, J.; Nasiatka, J.R.; Eimuller, T.; Ludescher, B.; Schutz, G.; Padmore, H.A.; Young, A.T.; Scholl, A.

    2007-03-23

    The role of orbital magnetism in the laser-induced demagnetization of Fe/Gd multilayers was investigated using time-resolved X-ray magnetic circular dichroism at 2-ps time resolution given by an x-ray streak camera. An ultrafast transfer of angular momentum from the spin via the orbital momentum to the lattice was observed which was characterized by rapidly thermalizing spin and orbital momenta. Strong interlayer exchange coupling between Fe and Gd led to a simultaneous demagnetization of both layers.

  10. Neutron Scattering Study on spin dynamics in superconducting (TlRb)2Fe4Se5

    SciTech Connect (OSTI)

    Chi, Songxue [ORNL; Ye, Feng [ORNL; Bao, Wei [Renmin University of China; Fang, Dr. Minghu [Zhejiang University; Wang, H.D. [Zhejiang University; Dong, C.H. [Zhejiang University; Savici, Andrei T [ORNL; Granroth, Garrett E [ORNL; Stone, Matthew B [ORNL; Fishman, Randy Scott [ORNL

    2013-01-01

    Spin dynamics in superconducting (Tl,Rb)2Fe4Se5 was investigated using the inelastic neutron scattering technique. Spin wave branches that span an energy range from 6.5 to 209 meV are success- fully described by a Heisenberg model whose dominant interactions include only the in-plane nearest (J1 and J0 1) and next nearest neighbor (J2 and J0 2) exchange terms within and between the tetramer spin blocks, respectively. These exchange constants, experimentally determined in this work, would crucially constrain the diverse theoretical viewpoints on magnetism and superconductivity in the Fe-based materials.

  11. Microstructure evolution of hot-deformed Nd-Fe-B anisotropic magnets

    SciTech Connect (OSTI)

    Liu, J. Hono, K.; Sepehri-Amin, H.; Ohkubo, T.; Hioki, K.; Hattori, A.

    2014-05-07

    The microstructural evolution of hot-deformed Nd-Fe-B magnets in each stage of hot-deformation process was studied using transmission electron microscopy and three dimensional atom probe (3DAP). The anisotropic growth of initially isotropic grains in rapidly solidified alloy occurs by annealing without pressing. 3DAP analyses showed a higher concentration of rare-earth elements in the intergranular phase parallel to the flat surface of platelet shaped Nd{sub 2}Fe{sub 14}B grains compared to that in the intergranular phase at the side of platelets.

  12. Nano-magnetism of magnetostriction in Fe{sub 35}Co{sub 65}

    SciTech Connect (OSTI)

    Lisfi, A.; Ren, T.; Wuttig, M.; Khachaturyan, A.

    2014-03-03

    The nature of the large magnetostriction in body-centered Fe-based solid solutions has been widely discussed in the literature. Here, we use a combination of magnetostriction, magnetization, torque, and transmission electron microscopy measurements of specially annealed Co{sub 65}Fe{sub 35} to show that the magnetostriction is caused by coherent uniaxial nano-precipitates. We show further that these nano-precipitates lower the magnetocrystalline anisotropy in these alloys to K{sub 1}?=??2.16?×?10{sup 4}?J/m{sup 3}.

  13. Dependency of tunneling magneto-resistance on Fe insertion-layer thickness in Co{sub 2}Fe{sub 6}B{sub 2}/MgO-based magnetic tunneling junctions

    SciTech Connect (OSTI)

    Chae, Kyo-Suk; Park, Jea-Gun

    2015-04-21

    For Co{sub 2}Fe{sub 6}B{sub 2}/MgO-based perpendicular magnetic tunneling junctions spin valves with [Co/Pd]{sub n}-synthetic-antiferromagnetic (SyAF) layers, the tunneling-magneto-resistance (TMR) ratio strongly depends on the nanoscale Fe insertion-layer thickness (t{sub Fe}) between the Co{sub 2}Fe{sub 6}B{sub 2} pinned layer and MgO tunneling barrier. The TMR ratio rapidly increased as t{sub Fe} increased up to 0.4?nm by improving the crystalline linearity of a MgO tunneling barrier and by suppressing the diffusion of Pd atoms from a [Co/Pd]{sub n}-SyAF. However, it abruptly decreased by further increasing t{sub Fe} in transferring interfacial-perpendicular magnetic anisotropy into the IMA characteristic of the Co{sub 2}Fe{sub 6}B{sub 2} pinned layer. Thus, the TMR ratio peaked at t{sub Fe}?=?0.4?nm: i.e., 120% at 29???m{sup 2}.

  14. Influence of topography and Co domain walls on the magnetization reversal of the FeNi layer in FeNi/Al2O3/Co magnetic tunnel junctions

    E-Print Network [OSTI]

    Kuch, Wolfgang

    Influence of topography and Co domain walls on the magnetization reversal of the FeNi layer in Fe situated on and situated be- tween steps is large. To test the influence of the topography microscopic view of the influence of the substrate-induced layer topography on the magnetization reversal

  15. Inelastic Neutron-Scattering Measurements of a Three-Dimensional Spin Resonance in the FeAs-Based BaFe1:9Ni0:1As2 Superconductor

    E-Print Network [OSTI]

    Hu, Jiangping

    Inelastic Neutron-Scattering Measurements of a Three-Dimensional Spin Resonance in the Fe, Purdue University, West Lafayette, Indiana 47907, USA 5 Neutron Scattering Science Division, Oak Ridge 2009) We use inelastic neutron scattering to study magnetic excitations of the Fe

  16. Study of difference in interfacial reaction at Fe{sub 3}O{sub 4}/ZnO and ZnO/Fe{sub 3}O{sub 4} heterostructure using synchrotron radiation

    SciTech Connect (OSTI)

    Wadikar, A. D. Master, Ridhi Choudhary, R. J. Phase, D. M.

    2014-04-24

    We have prepared Fe{sub 3}O{sub 4}/ZnO and ZnO/Fe{sub 3}O{sub 4} bilayer structure on p-Si substrate using pulsed laser deposition technique (PLD). X-ray diffraction study revealed (0001) oriented growth of ZnO and (111) oriented growth of Fe{sub 3}O{sub 4} in both the bilayer structure. We observed a change in the density of states near the Fermi level in valence band spectra in case of Fe{sub 3}O{sub 4}/ZnO bilayer when compared to that of ZnO/Fe{sub 3}O{sub 4}. Nonlinear current–voltage (I-V) characteristics were observed in both the samples confirmed that these bilayer structures can be used for spintronic application.

  17. Exchange bias effect in Au-Fe3O4 dumbbell nanoparticles induced by the charge transfer from gold

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

    Feygenson, Mikhail; Bauer, John C; Gai, Zheng; Marques, Carlos; Aronson, Meigan C.; Teng, Xiaowei; Su, Dong; Stanic, Vesna; Urban, Volker S; Kevin, Beyer; et al

    2015-08-10

    We have studied the origin of the exchange bias effect in the Au-Fe3O4 dumbbell nanoparticles in two samples with different sizes of the Au seed nanoparticles (4.1 and 2.7 nm) and same size of Fe3O4 nanoparticles (9.8 nm). The magnetization, small-angle neutron scattering, synchrotron x-ray diffraction and scanning transmission electron microscope measurements determined the antiferromagnetic FeO wüstite phase within Fe3O4 nanoparticles, originating at the interface with the Au nanoparticles. The interface between antiferromagnetic FeO and ferrimagnetic Fe3O4 is giving rise to the exchange bias effect. The strength of the exchange bias fields depends on the interfacial area and lattice mismatchmore »between both phases. We propose that the charge transfer from the Au nanoparticles is responsible for a partial reduction of the Fe3O4 into FeO phase at the interface with Au nanoparticles. The Au-O bonds are formed across the interface to accommodate an excess of oxygen released during the reduction of magnetite.« less

  18. Single-Ion Magnetic Anisotropy and Isotropic Magnetic Couplings in the Metal-Organic Framework Fe2(dobdc)

    E-Print Network [OSTI]

    are here assessed with quantum chemical calculations performed on a finite size cluster. It is shown.16 The structure of this compound consists of high-spin FeII ions arranged in a helical pattern along columns at the intersection of three hexagonal pores. As synthesized, each FeII ion is hexacoordinate; five coordination sites

  19. An Electron Microscopy Investigation of the Transient Stage Oxidation Products in an Fe-22Cr Alloy with Ce and La

    E-Print Network [OSTI]

    Laughlin, David E.

    as interconnector materials.[1] However, lowering of the operational temperature of SOFCs from approximately 1273 K; these properties make Fe-Cr alloys favorable candidates for interconnector materials.[1,3] Research has been. A major problem with metallic interconnectors based on Fe-Cr alloys, is their reactivity

  20. Simplified Electrochemical and Thermal Model of LiFePO4-Graphite Li-Ion Batteries for Fast Charge Applications

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Simplified Electrochemical and Thermal Model of LiFePO4- Graphite Li-Ion Batteries for Fast Charge, a simplified electrochemical and thermal model of LiFePO4-graphite based Li-ion batteries is developed for battery management system (BMS) applications and comprehensive aging investigations. Based on a modified

  1. Low-temperature magnetic properties of greigite (Fe3S4) Liao Chang and Andrew P. Roberts

    E-Print Network [OSTI]

    Utrecht, Universiteit

    Low-temperature magnetic properties of greigite (Fe3S4) Liao Chang and Andrew P. Roberts National 115, Taiwan [1] We provide comprehensive low-temperature magnetic results for greigite (Fe3S4) across no low- temperature magnetic transitions, but we also document that it has strong domain-state dependence

  2. FeCycle: Attempting an iron biogeochemical budget from a mesoscale SF6 tracer experiment in unperturbed low iron waters

    E-Print Network [OSTI]

    Wilhelm, Steven W.

    FeCycle: Attempting an iron biogeochemical budget from a mesoscale SF6 tracer experiment to ocean physics. In summer 2003 we conducted FeCycle, a 10-day mesoscale tracer release in HNLC waters SE biogeochemical budget from a mesoscale SF6 tracer experiment in unperturbed low iron waters, Global Biogeochem

  3. Exchange bias effect in Au-Fe3O4 dumbbell nanoparticles induced by the charge transfer from gold

    SciTech Connect (OSTI)

    Feygenson, Mikhail; Bauer, John C; Gai, Zheng; Marques, Carlos; Aronson, Meigan C.; Teng, Xiaowei; Su, Dong; Stanic, Vesna; Urban, Volker S; Kevin, Beyer; Dai, Sheng

    2015-01-01

    We have studied the origin of the exchange bias effect in the Au-Fe3O4 dumbbell nanoparticles in two samples with different sizes of the Au seed nanoparticles (4.1 and 2.7 nm) and same size of Fe3O4 nanoparticles (9.8 nm). The magnetization, small-angle neutron scattering, synchrotron x-ray diffraction and scanning transmission electron microscope measurements determined the antiferromagnetic FeO w ustite phase within Fe3O4 nanoparticles, originating at the interface with the Au nanoparticles. The interface between antiferromagnetic FeO and ferrimagnetic Fe3O4 is giving rise to the exchange bias effect. The strength of the exchange bias fields depends on the interfacial area and lattice mismatch between both phases. We propose that the charge transfer from the Au nanoparticles is responsible for a partial reduction of the Fe3O4 into FeO phase at the interface with Au nanoparticles. The Au-O bonds are formed across the interface to accommodate an excess of oxygen released during the reduction of magnetite.

  4. 3036 IEEE TRANSACTIONS ON MAGNETICS, VOL. 42, NO. 10, OCTOBER 2006 Phase Transformation of FePt Nanoparticles

    E-Print Network [OSTI]

    Liu, J. Ping

    3036 IEEE TRANSACTIONS ON MAGNETICS, VOL. 42, NO. 10, OCTOBER 2006 Phase Transformation of Fe temperature for the fcc to fct phase transformation. Doping by elements such as Ag, Au, and Cu in the Fe so that these methods are not suitable for Digital Object Identifier 10.1109/TMAG.2006

  5. Controlled synthesis of CoFe2O4 nano-octahedra Andr Lus Lopes-Moriyamaa,b *

    E-Print Network [OSTI]

    Boyer, Edmond

    1 Title Controlled synthesis of CoFe2O4 nano-octahedra Authors André Luís Lopes cetyltrimethylammonium bromide (CTAB) hindered the formation of goethite, which favored the production of a pure CoFe2O4" DOI : 10.1016/j.powtec.2014.01.080 #12;2 Hydrothermal synthesis; nanoparticles; cobalt ferrite; shape

  6. Sorption and transport of aqueous FeII in a goethite-coated sand column under anoxic

    E-Print Network [OSTI]

    Boyer, Edmond

    1 Sorption and transport of aqueous FeII in a goethite-coated sand column under anoxic conditions K and dynamic flow conditions to evaluate the sorption of FeII onto three goethites (G1, G2 and G3) having batch experiments were combined with hydrodynamic parameters to simulate breakthrough curves in goethite

  7. Highway Geology Symposium Santa Fe, 2008 HGS Session 5 -Paper 5.2 Page 1 of 21

    E-Print Network [OSTI]

    Haneberg, William C.

    59th Highway Geology Symposium Santa Fe, 2008 HGS Session 5 - Paper 5.2 Page 1 of 21 59 TH HIGHWAY GEOLOGY SYMPOSIUM 2008 Santa Fe, New Mexico SESSION 5 PAPER #5.2 REVISITING AN OLD PROJECT WITH NEW TECHNOLOGY-- DIGITAL TERRAIN MODELING AND MULTI-LAYERED VIRTUAL GEOLOGIC HAZARD MAPPING ALONG A PROPOSED

  8. A Simplified Electrochemical and Thermal Aging Model of LiFePO4-Graphite Li-ion Batteries

    E-Print Network [OSTI]

    1 A Simplified Electrochemical and Thermal Aging Model of LiFePO4-Graphite Li-ion Batteries: Power of a commercial LiFePO4-graphite Li-ion battery. Compared to the isothermal reference, the mechanism of porosity;2 Due to their high power and energy densities, Li-ion technologies are the leading battery systems

  9. Small Polaron Hopping in LixFePO4 Solid Solutions: Coupled Lithium-Ion and Electron Mobility

    E-Print Network [OSTI]

    Ryan, Dominic

    Small Polaron Hopping in LixFePO4 Solid Solutions: Coupled Lithium-Ion and Electron Mobility Brian recognized as very promising electrodes for lithium-ion batteries because of their energy storage capacity the factors governing electron and ion transport within the lattice. Lithium extraction from LiFePO4 results

  10. Positive exchange bias and upward magnetic relaxation in a Fe-film/CoO-nanoparticle hybrid system

    E-Print Network [OSTI]

    Krishnan, Kannan M.

    Positive exchange bias and upward magnetic relaxation in a Fe-film/CoO- nanoparticle hybrid system exchange bias and upward magnetic relaxation in a Fe-film/CoO-nanoparticle hybrid system Wei Zhang) Heat-induced damping modification in yttrium iron garnet/platinum hetero-structures Appl. Phys. Lett

  11. Enhanced hydrogen storage properties of LiAlH4 catalyzed by CoFe2O4 nanoparticles

    E-Print Network [OSTI]

    Volinsky, Alex A.

    Enhanced hydrogen storage properties of LiAlH4 catalyzed by CoFe2O4 nanoparticles Ziliang Li The catalytic effects of CoFe2O4 nanoparticles on the hydrogen storage properties of LiAlH4 prepared by ball of advanced hydrogen storage materials for safely storing it at high gravimetric and volumetric densities.4

  12. LARGE-AREA [Fe II] LINE MAPPING OF THE SUPERNOVA REMNANT IC 443 WITH THE IRSF/SIRIUS

    SciTech Connect (OSTI)

    Kokusho, Takuma; Nagayama, Takahiro; Kaneda, Hidehiro; Ishihara, Daisuke [Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya 464-8602 (Japan); Lee, Ho-Gyu; Onaka, Takashi, E-mail: kokusho@u.phys.nagoya-u.ac.jp [Department of Astronomy, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2013-05-01

    We present the results of near-infrared (near-IR) [Fe II] line mapping of the supernova remnant IC 443 with IRSF/SIRIUS, using the two narrow-band filters tuned for the [Fe II] 1.257 {mu}m and [Fe II] 1.644 {mu}m lines. Covering a large area of 30' Multiplication-Sign 35', our observations reveal that [Fe II] filamentary structures exist all over the remnant, not only in an ionic shock shell, but also in a molecular shock shell and a central region inside the shells. With the two [Fe II] lines, we performed corrections for dust extinction to derive the intrinsic line intensities. We also obtained the intensities of thermal emission from the warm dust associated with IC 443, using the far- and mid-IR images taken with AKARI and Spitzer, respectively. As a result, we find that the [Fe II] line emission relative to the dust emission notably enhances in the inner central region. We discuss causes of the enhanced [Fe II] line emission, estimating the Fe{sup +} and dust masses.

  13. Thermo-mechanical FE model with memory effect for 304L austenitic stainless steel presenting microstructure gradient

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Thermo-mechanical FE model with memory effect for 304L austenitic stainless steel presenting. Keywords: 304L stainless steel; thermal fatigue; F.E. modelling. #12;2 1 Introduction The 304L stainless-hardened stainless steel were carried out by Taleb and Hauet [4], Taheri et al [5]. To predict the behaviour

  14. Thermal Expansion, Heat Capacity, and Thermal Conductivity of Nickel Ferrite (NiFe[subscript 2]O[subscript 4])

    E-Print Network [OSTI]

    Nelson, Andrew T.

    Nickel ferrite (NiFe[subscript 2]O[subscript 4]) is a major constituent of the corrosion deposits formed on the exterior of nuclear fuel cladding tubes during operation. NiFe[subscript 2]O[subscript 4] has attracted much ...

  15. Microstructures and Mechanical Properties of Compositionally Complex Co-free FeNiMnCr18 FCC Solid Solution Alloy

    SciTech Connect (OSTI)

    Wu, Zhenggang [The University of Tennessee; Bei, Hongbin [ORNL

    2015-01-01

    Recently,a structurally-simplebutcompositionally-complex FeNiCoMnCr highentropyalloywasfoundto haveexcellentmechanicalproperties(e.g.,highstrengthandductility).Tounderstandthepotentialof using highentropyalloysasstructuralmaterialsforadvancednuclearreactorandpowerplants,itis necessary tohaveathoroughunderstandingoftheirstructuralstabilityandmechanicalpropertiesde- gradation underneutronirradiation.ThisrequiresustodevelopasimilarmodelalloywithoutCobe- cause materialwithCowillmakepost-neutron-irradiationtestingdifficult duetotheproductionofthe 60Co radioisotope.Toachievethisgoal,aFCC-structuredsingle-phasealloywithacompositionof FeNiMnCr18 wassuccessfullydeveloped.Thisnear-equiatomicFeNiMnCr18 alloy hasgoodmalleability and itsmicrostructurecanbecontrolledbythermomechanicalprocessing.Byrollingandannealing,the as-cast elongated-grained-microstructureisreplacedbyhomogeneousequiaxedgrains.Themechanical properties (e.g.,strengthandductility)oftheFeNiMnCr18 alloy arecomparabletothoseoftheequiatomic FeNiCoMnCr highentropyalloy.Bothstrengthandductilityincreasewithdecreasingdeformation temperature,withthelargestdifferenceoccurringbetween293and77K.Extensivetwin-bandswhich are bundlesofnumerousindividualtwinsareobservedwhenitistensile-fracturedat77K.Notwin bands aredetectedbyEBSDformaterialsdeformedat293Kandhigher.Theunusualtemperature-de- pendencies ofUTSanduniformelongationcouldbecausedbythedevelopmentofthedensetwin substructure, twin-dislocationinteractionsandtheinteractionsbetweenprimaryandsecondarytwin- ning systemswhichresultinamicrostructurerefinement andhencecauseenhancedstrainhardening and postponednecking.

  16. Li{sub 4}FeH{sub 6}: Iron-containing complex hydride with high gravimetric hydrogen density

    SciTech Connect (OSTI)

    Saitoh, Hiroyuki, E-mail: cyto@spring8.or.jp [Quantum Beam Science Center, Japan Atomic Energy Agency, Hyogo 679-5148 (Japan); Takagi, Shigeyuki; Matsuo, Motoaki; Aoki, Katsutoshi [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Iijima, Yuki [WPI-Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Endo, Naruki [Renewable Energy Research Center, National Institute of Advanced Industrial Science and Technology, Fukushima 963-0215 (Japan); Orimo, Shin-ichi [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); WPI-Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)

    2014-07-01

    Li{sub 4}FeH{sub 6}, which has the highest gravimetric hydrogen density of iron-containing complex hydrides reported so far, is synthesized by hydrogenation of a powder mixture of iron and LiH above 6.1 GPa at 900?°C. In situ synchrotron radiation X-ray diffraction measurements reveal that while kinetics require high temperature and thus high pressure for the synthesis, Li{sub 4}FeH{sub 6} is expected to be thermodynamically stable slightly below room temperature at ambient pressure; further synthetic studies to suppress the kinetic effects may enable us to synthesize Li{sub 4}FeH{sub 6} at moderate pressures. Li{sub 4}FeH{sub 6} can be recovered at ambient conditions where Li{sub 4}FeH{sub 6} is metastable.

  17. The Role of FeS in Initial Activation and Performance Degradation of Na-NiCl2 Batteries

    SciTech Connect (OSTI)

    Li, Guosheng; Lu, Xiaochuan; Kim, Jin Yong; Engelhard, Mark H.; Lemmon, John P.; Sprenkle, Vincent L.

    2014-12-25

    The role of iron sulfide (FeS) in initial cell activation and degradation in the Na-NiCl2 battery was investigated in this work. The research focused on identifying the effects of the FeS level on the electrochemical performance and morphological changes in the cathode. The x-ray photoelectron spectroscopy study along with battery tests revealed that FeS plays a critical role in initial battery activation by removing passivation layers on Ni particles. It was also found that the optimum level of FeS in the cathode resulted in minimum Ni particle growth and improved battery cycling performance. The results of electrochemical characterization indicated that sulfur species generated in situ during initial charging, such as polysulfide and sulfur, are responsible for removing the passivation layer. Consequently, the cells containing elemental sulfur in the cathode exhibited similar electrochemical behavior during initial charging compared to that of the cells containing FeS.

  18. Photocatalytic performances and activities of Ag-doped CuFe{sub 2}O{sub 4} nanoparticles

    SciTech Connect (OSTI)

    Zhu, Zhengru; Li, Xinyong; Zhao, Qidong; Li, Yonghua; Sun, Caizhi; Cao, Yongqiang

    2013-08-01

    Graphical abstract: - Highlights: • CuFe{sub 2}O{sub 4} nanocrystals were synthesized by a co-precipitation method. • Ag/CuFe{sub 2}O{sub 4} catalyst was prepared by the wetness impregnation strategy. • The structural properties of Ag/CuFe{sub 2}O{sub 4} were investigated by XRD, TEM, DRS, and XPS techniques. • Ag/CuFe{sub 2}O{sub 4} has higher photocatalytic activity. - Abstract: In this work, CuFe{sub 2}O{sub 4} nanoparticles were synthesized by a chemical co-precipitation route. The Ag/CuFe{sub 2}O{sub 4} catalyst was prepared based on the CuFe{sub 2}O{sub 4} nanoparticles by the incipient wetness impregnation strategy, which showed excellent photoelectric property and catalytic activity. The structural properties of these samples were systematically investigated by X-ray powder diffraction (XRD), transmission electronic microscopy (TEM), UV–vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR) techniques. The photo-induced charge separation in the samples was demonstrated by surface photovoltage (SPV) measurement. The photocatalytic degradation of 4-CP by the Ag/CuFe{sub 2}O{sub 4} and CuFe{sub 2}O{sub 4} samples were comparatively studied under xenon lamp irradiation. The results indicate that the Ag/CuFe{sub 2}O{sub 4} sample exhibited the higher efficiency for the degradation of 4-CP.

  19. The vibrational spectrum of FeO{sub 2}{sup +} isomers—Theoretical benchmark and experiment

    SciTech Connect (OSTI)

    Maier, Toni M.; Boese, A. Daniel; Sauer, Joachim; Wende, Torsten; Fagiani, Matias; Asmis, Knut R.

    2014-05-28

    Infrared photodissociation is used to record the vibrational spectrum of FeO{sub 2}{sup +}(He){sub 2–4} which shows three bands at 1035, 980, and 506 cm{sup ?1}. Quantum chemical multi-reference configuration interaction calculations (MRCISD) of structures and harmonic frequencies show that these bands are due to two different isomers, an inserted dioxo complex with Fe in the +V oxidation state and a side-on superoxo complex with Fe in the +II oxidation state. These two are separated by a substantial barrier, 53 kJ/mol, whereas the third isomer, an end-on complex between Fe{sup +} and an O{sub 2} molecule, is easily converted into the side-on complex. For all three isomers, states of different spin multiplicity have been considered. Our best energies are computed at the MRCISD+Q level, including corrections for complete active space and basis set extension, core-valence correlation, relativistic effects, and zero-point vibrational energy. The average coupled pair functional (ACPF) yields very similar energies. Density functional theory (DFT) differs significantly from our best estimates for this system, with the TPSS functional yielding the best results. The other functionals tested are BP86, PBE, B3LYP, TPSSh, and B2PLYP. Complete active space second order perturbation theory (CASPT2) performs better than DFT, but less good than ACPF.

  20. An investigation of Fe XV emission lines in solar flare spectra

    E-Print Network [OSTI]

    F P Keenan; K M Aggarwal; D S Bloomfield; A Z Msezane; K G Widing

    2005-12-22

    Previously, large discrepancies have been found between theory and observation for Fe XV emission line ratios in solar flare spectra covering the 224-327 A wavelength range, obtained by the Naval Research Laboratory's S082A instrument on board Skylab. These discrepancies have been attributed to either errors in the adopted atomic data or the presence of additional atomic processes not included in the modelling, such as fluorescence. However our analysis of these plus other S082A flare observations (the latter containing Fe XV transitions between 321-482 A), performed using the most recent Fe XV atomic physics calculations in conjunction with a CHIANTI synthetic flare spectrum, indicate that blending of the lines is primarily responsible for the discrepancies. As a result, most Fe XV lines cannot be employed as electron density diagnostics for solar flares, at least at the spectral resolution of S082A and similar instruments (i.e. ~ 0.1 A). An exception is the intensity ratio I(321.8 A)/I(327.0 A), which appears to provide good estimates of the electron density at this spectral resolution.

  1. Ferropnictide superconductors, i.e., superconductors that contain Fe and As, have superconducting transition

    E-Print Network [OSTI]

    Weston, Ken

    Ferropnictide superconductors, i.e., superconductors that contain Fe and As, have superconducting of these materials could not carry a large superconducting current because grain boundaries reduce the critical Hellstrom (DMR-Award 1006584) and Gregory S. Boebinger (DMR-Award 0654118) Applied Superconductivity Center

  2. Adiabatic shear banding in ultrafine-grained Fe processed by severe plastic deformation

    E-Print Network [OSTI]

    Wei, Qiuming

    . Keywords: Shear bands; Severe plastic deformation; Ultrafine microstructure; Mechanical properties; DynamicAdiabatic shear banding in ultrafine-grained Fe processed by severe plastic deformation Q. Wei a December 2003; accepted 17 December 2003 Abstract We have investigated the plastic deformation behavior

  3. Doped LiFePO? cathodes for high power density lithium ion batteries

    E-Print Network [OSTI]

    Bloking, Jason T. (Jason Thompson), 1979-

    2003-01-01

    Olivine LiFePO4 has received much attention recently as a promising storage compound for cathodes in lithium ion batteries. It has an energy density similar to that of LiCoO 2, the current industry standard for cathode ...

  4. Nitric Oxide in Biological Denitrification: Fe/Cu Metalloenzyme and Metal Complex NOx Redox Chemistry

    E-Print Network [OSTI]

    Schroeder, Imke

    Nitric Oxide in Biological Denitrification: Fe/Cu Metalloenzyme and Metal Complex NOx Redox Nitrite Reductase: 1204 2. Copper Nitrite Reductases 1206 B. Nitric Oxide Reductase 1208 1. Structure 1208 Nitric Oxide Sensors, Scavengers, and Delivery Agents 1227 IV. Concluding Remarks 1229 V. Acknowledgments

  5. Fe-rich ejecta in the supernova remnant G352.7–0.1 with Suzaku

    SciTech Connect (OSTI)

    Sezer, A.; Gök, F.

    2014-07-20

    In this work, we present results from a ?201.6 ks observation of G352.7–0.1 using the X-ray Imaging Spectrometer on board Suzaku X-ray Observatory. The X-ray emission from the remnant is well described by two-temperature thermal models of non-equilibrium ionization with variable abundances with a column density of N{sub H} ? 3.3 × 10{sup 22} cm{sup –2}. The soft component is characterized by an electron temperature of kT{sub e} ? 0.6 keV, an ionization timescale of ? ? 3.4 × 10{sup 11} cm{sup –3} s, and enhanced Si, S, Ar, and Ca abundances. The hard component has kT{sub e} ? 4.3 keV, ? ? 8.8 × 10{sup 9} cm{sup –3} s, and enhanced Fe abundance. The elemental abundances of Si, S, Ar, Ca, and Fe are found to be significantly higher than the solar values that confirm the presence of ejecta. We detected strong Fe K-shell emission and determined its origin to be the ejecta for the first time. The detection of Fe ejecta with a lower ionization timescale favors a Type Ia origin for this remnant.

  6. Magnetic structure at low temperatures in FeGe{sub 2}

    SciTech Connect (OSTI)

    Babu, P. D.; Mishra, P. K.; Dube, V.; Ravikumar, G.; Mishra, R.; Sastry, P. U.

    2014-04-24

    Magnetic phase of FeGe{sub 2} intermetallic is studied using low-temperature neutron diffraction and DC magnetization. Zero-magnetic-field neutron scattering data shows the presence of an antiferromagnetic phase in the low temperature range. We find the evidence of the presence of a ferromagnetic order overriding on the predominantly antiferromagnetic phase at low temperatures.

  7. Temperature Dependence of Aliovalent-vanadium Doping in LiFePO4 Cathodes

    SciTech Connect (OSTI)

    Harrison, Katharine L; Bridges, Craig A; Paranthaman, Mariappan Parans; Idrobo Tapia, Juan C; Manthiram, Arumugam; Goodenough, J. B.; Segre, C; Katsoudas, John; Maroni, V. A.

    2013-01-01

    Vanadium-doped olivine LiFePO4 cathode materials have been synthesized by a novel low-temperature microwave-assisted solvothermal (MW-ST) method at 300 oC. Based on chemical and powder neutron/X-ray diffraction analysis, the compositions of the synthesized materials were found to be LiFe1-3x/2Vx x/2PO4 (0 x 0.2) with the presence of a small number of lithium vacancies charge-compensated by V4+, not Fe3+, leading to an average oxidation state of ~ 3.2+ for vanadium. Heating the pristine 15 % V-doped sample in inert or reducing atmospheres led to a loss of vanadium from the olivine lattice with the concomitant formation of a Li3V2(PO4)3 impurity phase; after phase segregation, a partially V-doped olivine phase remained. For comparison, V-doped samples were also synthesized by conventional ball milling and heating, but only ~ 10 % V could be accommodated in the olivine lattice in agreement with previous studies. The higher degree of doping realized with the MW-ST samples demonstrates the temperature dependence of the aliovalent-vanadium doping in LiFePO4.

  8. A Suzaku Observation of the Low-Ionization Fe-Line Emission from RCW 86

    E-Print Network [OSTI]

    Masaru Ueno; Rie Sato; Jun Kataoka; Aya Bamba; Ilana Harrus; Junko Hiraga; John P. Hughes; Caroline A. Kilbourne; Katsuji Koyama; Motohide Kokubun; Hiroshi Nakajima; Masanobu Ozaki; Robert Petre; Tadayuki Takahashi; Takaaki Tanaka; Hiroshi Tomida; Hiroya Yamaguchi

    2006-10-13

    The newly operational X-ray satellite Suzaku observed the southwestern quadrant of the supernova remnant (SNR) RCW 86 in February 2006 to study the nature of the 6.4 keV emission line first detected with the Advanced Satellite for Cosmology and Astronomy (ASCA). The new data confirm the existence of the line, localizing it for the first time; most of the line emission is adjacent and interior to the forward shock and not at the locus of the continuum hard emission. We also report the first detection of a 7.1 keV line that we interpret as the K-beta emission from low-ionization iron. The Fe-K line features are consistent with a non-equilibrium plasma of Fe-rich ejecta with n_{e}t <~ 10^9 cm^-3 s and kT_{e} ~ 5 keV. This combination of low n_{e}t and high kT_{e} suggests collisionless electron heating in an SNR shock. The Fe K-alpha line shows evidence for intrinsic broadening, with a width of 47 (34--59) eV (99% error region). The difference of the spatial distributions of the hard continuum above 3 keV and the Fe-K line emission support a synchrotron origin for the hard continuum.

  9. Los Alamos National Laboratory Modular Pumped Hydro Feasibility Study for Santa Fe Community College

    SciTech Connect (OSTI)

    Bibeault, Mark Leonide

    2015-04-21

    Report on the Economic Energy Assessment for a community college in Santa Fe, New Mexico. Report shows graphically the demand for energy in the month of September, and illustrates the production of electricity as it goes onto the grid for use.

  10. Ferromagnetic ordering of Cr and Fe doped p-type diamond: An ab initio study

    SciTech Connect (OSTI)

    Benecha, E. M.; Lombardi, E. B.

    2014-02-21

    Ferromagnetic ordering of transition metal dopants in semiconductors holds the prospect of combining the capabilities of semiconductors and magnetic systems in single hybrid devices for spintronic applications. Various semiconductors have so far been considered for spintronic applications, but low Curie temperatures have hindered room temperature applications. We report ab initio DFT calculations on the stability and magnetic properties of Fe and Cr impurities in diamond, and show that their ground state magnetic ordering and stabilization energies depend strongly on the charge state and type of co-doping. We predict that divacancy Cr{sup +2} and substitutional Fe{sup +1} order ferromagnetically in p-type diamond, with magnetic stabilization energies (and magnetic moment per impurity ion) of 16.9 meV (2.5 ?{sub B}) and 33.3 meV (1.0 ?{sub B}), respectively. These magnetic stabilization energies are much larger than what has been achieved in other semiconductors at comparable impurity concentrations, including the archetypal dilute magnetic semiconductor GaAs:Mn. In addition, substitutional Fe{sup +1} exhibits a strong half-metallic character, with the Fermi level crossing bands in only the spin down channel. These results, combined with diamond’s extreme properties, demonstrate that Cr or Fe dopedp-type diamond may successfully be considered in the search for room temperature spintronic materials.

  11. Strain control magnetocrystalline anisotropy of Ta/FeCo/MgO heterostructures

    SciTech Connect (OSTI)

    Ong, P. V.; Kioussis, Nicholas; Amiri, P. Khalili; Wang, K. L.; Carman, Gregory P.

    2015-05-07

    Using ab initio electronic structure calculations, we have investigated the effect of epitaxial strain on magnetocrystalline anisotropy (MCA) of Ta/FeCo/MgO heterostructure. At small expansive strains on the FeCo layer, the system exhibits perpendicular MCA (PMA). Strain not only has a profound effect on the value of MCA but also induces a switching of magnetic easy axis. Analysis of the energy- and k-resolved distribution of orbital characters of the minority-spin band reveals that a significant contribution to PMA at zero strain arises from the spin-orbit coupling between occupied d{sub x{sup 2}?y{sup 2}} and unoccupied d{sub xy} states, derived from Fe at the FeCo/MgO interface. The strain effect is attributed to strain-induced shifts of spin-orbit coupled d-states. Our work demonstrates that strain engineering can open a viable pathway towards tailoring magnetic properties for spintronic applications.

  12. Vertically aligned P(VDF-TrFE) core-shell structures on flexible pillar arrays

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

    Choi, Yoon-Young; Yun, Tae Gwang; Qaiser, Nadeem; Paik, Haemin; Roh, Hee Seok; Hong, Jongin; Hong, Seungbum; Han, Seung Min; No, Kwangsoo

    2015-06-04

    PVDF and P(VDF-TrFE) nano- and micro- structures are widely used due to their potential applications in several fields, including sensors, actuators, vital sign transducers, and energy harvesters. In this study, we developed vertically aligned P(VDF-TrFE) core-shell structures using high modulus polyurethane acrylate (PUA) pillars as the support structure to maintain the structural integrity. In addition, we were able to improve the piezoelectric effect by 1.85 times from 40 ± 2 to 74 ± 2 pm/V when compared to the thin film counterpart, which contributes to the more efficient current generation under a given stress, by making an effective use ofmore »the P(VDF-TrFE) thin top layer as well as the side walls. We attribute the enhancement of piezoelectric effects to the contributions from the shell component and the strain confinement effect, which was supported by our modeling results. We envision that these organic-based P(VDF-TrFE) core-shell structures will be used widely as 3D sensors and power generators because they are optimized for current generations by utilizing all surface areas, including the side walls of core-shell structures.« less

  13. Method for improving voltage regulation of batteries, particularly Li/FeS.sub.2 thermal batteries

    DOE Patents [OSTI]

    Godshall, Ned A. (Albuquerque, NM)

    1988-01-01

    Batteries are improved, especially with respect to voltage regulation properties, by employing as anode and cathode compositions, those which fall in a thermodynamically invariant region of the metallurgical phase diagram of the combination of the constituent components. The invention is especially useful in the Li/FeS.sub.2 system.

  14. Magnetic order tuned by Cu substitution in Fe1.1–zCuzTe

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

    Wen, Jinsheng; Xu, Zhijun; Xu, Guangyong; Lumsden, M. D.; Valdivia, P. N.; Bourret-Courchesne, E.; Gu, Genda; Lee, Dung-Hai; Tranquada, J. M.; Birgeneau, R. J.

    2012-07-02

    We study the effects of Cu substitution in Fe?.?Te, the nonsuperconducting parent compound of the iron-based superconductor, Fe??yTe??xSex, utilizing neutron scattering techniques. It is found that the structural and magnetic transitions, which occur at ~60 K without Cu, are monotonically depressed with increasing Cu content. By 10% Cu for Fe, the structural transition is hardly detectable, and the system becomes a spin glass below 22 K, with a slightly incommensurate ordering wave vector of (0.5–?, 0, 0.5) with ? being the incommensurability of 0.02, and correlation length of 12 Å along the a axis and 9 Å along the cmore »axis. With 4% Cu, both transition temperatures are at 41 K, though short-range incommensurate order at (0.42, 0, 0.5) is present at 60 K. With further cooling, the incommensurability decreases linearly with temperature down to 37 K, below which there is a first-order transition to a long-range almost-commensurate antiferromagnetic structure. A spin anisotropy gap of 4.5 meV is also observed in this compound. Our results show that the weakly magnetic Cu has a large effect on the magnetic correlations; it is suggested that this is caused by the frustration of the exchange interactions between the coupled Fe spins.« less

  15. Ion irradiation testing and characterization of FeCrAl candidate alloys

    SciTech Connect (OSTI)

    Anderoglu, Osman; Aydogan, Eda; Maloy, Stuart Andrew; Wang, Yongqiang

    2014-10-29

    The Fuel Cycle Research and Development program’s Advanced Fuels Campaign has initiated a multifold effort aimed at facilitating development of accident tolerant fuels. This effort involves development of fuel cladding materials that will be resistant to oxidizing environments for extended period of time such as loss of coolant accident. Ferritic FeCrAl alloys are among the promising candidates due to formation of a stable Al?O? oxide scale. In addition to being oxidation resistant, these promising alloys need to be radiation tolerant under LWR conditions (maximum dose of 10-15 dpa at 250 – 350°C). Thus, in addition to a number of commercially available alloys, nuclear grade FeCrAl alloys developed at ORNL were tested using high energy proton irradiations and subsequent characterization of irradiation hardening and damage microstructure. This report summarizes ion irradiation testing and characterization of three nuclear grade FeCrAl cladding materials developed at ORNL and four commercially available Kanthal series FeCrAl alloys in FY14 toward satisfying FCRD campaign goals.

  16. Oil & Natural Gas Technology DOE Award No.: DE-FE 0009963

    E-Print Network [OSTI]

    Report (Period ending 03/31/2014) Measurement and Interpretation of Seismic Velocities and Attenuations agency thereof. #12;3 Abstract: Measurement and Interpretation of Seismic Velocities and Attenuations in Hydrate-Bearing Sediments Grant/Cooperative Agreement DE-FE 0009963. This project to measure the seismic

  17. Method for improving voltage regulation of batteries, particularly Li/FeS/sub 2/ thermal batteries

    DOE Patents [OSTI]

    Godshall, N.A.

    1986-06-10

    Batteries are improved, especially with respect to voltage regulation properties, by employing as anode and cathode compositions, those which fall in a thermodynamically invariant region of the metallurgical phase diagram of the combination of the constituent components. The invention is especially useful in the Li/FeS/sub 2/ system.

  18. Solubility and freezing effects of Fe2+ solutions representative of upper tropospheric and lower

    E-Print Network [OSTI]

    Solubility and freezing effects of Fe2+ and Mg2+ in H2SO4 solutions representative of upper, it is unclear how these impurities could affect particle freezing. To address these questions, we have particles. Bulk freezing experiments were also carried out on H2SO4 solutions containing amounts

  19. The Utility of FeVO4 in Combination with Stabilized Titanias for Mobile SCR Application

    Broader source: Energy.gov [DOE]

    Selective catalytic reduction studies with ammonia/NO model gas mixtures were used to screen mixed FeVO4/titania powders for activity in both fresh and aged conditions; reaction of ammonia in the absence of NO was also used as measure of ammonia oxidation tendency at elevated reaction temperatures

  20. Chemical Engineering Journal 139 (2008) 208212 Electrodeposition of maghemite ( -Fe2O3) nanoparticles

    E-Print Network [OSTI]

    2008-01-01

    Chemical Engineering Journal 139 (2008) 208­212 Electrodeposition of maghemite ( -Fe2O3. Myunga, a Department of Chemical and Environmental Engineering, University of California-Riverside, Riverside, CA 92521, United States b Department of Environmental Science and Engineering, Gwangju Institute

  1. (magneto-optical Barnett Gd22Fe74.6Co3.4 (picosecond)

    E-Print Network [OSTI]

    #12;#12;#12;#12;i (magneto-optical Barnett effect) Gd22Fe quantum coherence control to figure out it's mechanism. We referred to as magneto-optical Barnett effect must be at work. Traditionally, Barnett effect is the magnetization of an uncharged body when spun

  2. Li Conductivity in LixMPO4 ,,M Mn, Fe, Co, Ni... Olivine Materials

    E-Print Network [OSTI]

    Ceder, Gerbrand

    , USA Materials with the olivine LixMPO4 structure form an important class of rechargeable battery-ion batteries. In particular, early work on the LixFePO4 material demonstrated its potential to reversibly cycle in supercells containing eight formula units to reduce interactions between images of the Li being moved. The Li

  3. Tracing bottom water oxygenation with sedimentary Mn/Fe ratios in Lake Zurich, Switzerland

    E-Print Network [OSTI]

    Gilli, Adrian

    Tracing bottom water oxygenation with sedimentary Mn/Fe ratios in Lake Zurich, Switzerland and Management, Seestrasse 79, CH-6047 Kastanienbaum, Switzerland b ETH Zurich, Institute for Biogeochemistry and Pollution Dynamics, Universitaetstrasse 16, CH-8092 Zurich, Switzerland c ETH Zurich, Geological Institute

  4. Investigation of primary Li-Si/FeS/sub 2/ cells

    SciTech Connect (OSTI)

    Redey, L.; Smaga, J.A.; Battles, J.E.; Guidotti, R.

    1987-04-01

    The factors that limit the performance of thermally activated Li-Si/FeS/sub 2/ batteries were defined through the use of electrochemical characterization tests and post-test examinations. For the characterization tests, 82 individual cells were instrumented with multiple voltage sensors and discharged under isothermal and isobaric conditions. The voltage data for the sensors were recorded to determine the ohmic and electrochemical impedances of each cell component at different levels of discharge. The data analysis completed to date has demonstrated that this approach can successfully differentiate the influence of various operating parameters (e.g., temperature, current density), electrode structures (e.g., FeS/sub 2/ particle size), and additives on cell capacity, specific energy, and power capability. Thirty cells selected from these tests and additional tests at SNL were examined using optical and scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. These analyses documented microstructural and compositional changes in the active materials and electrolyte. In general, the electrochemical impedance of the FeS/sub 2/ electrode limited cell performance. Several methods (including use of fine FeS/sub 2/ particle size, graphite additions, and higher operating temperatures) produced measurable reductions in this impedance and yielded significant improvements in specific energy and power. Additions of KCl to the negative electrode extended the low-temperature capacity of this electrode by counterbalancing gradients in electrolyte composition that develop during discharge.

  5. FeAl and Mo-Si-B Intermetallic Coatings Prepared by Thermal Spraying

    SciTech Connect (OSTI)

    Totemeier, T.C.; Wright, R.N.; Swank, W.D.

    2003-04-22

    FeAl and Mo-Si-B intermetallic coatings for elevated temperature environmental resistance were prepared using high-velocity oxy-fuel (HVOF) and air plasma spray (APS) techniques. For both coating types, the effect of coating parameters (spray particle velocity and temperature) on the microstructure and physical properties of the coatings was assessed. Fe-24Al (wt.%) coatings were prepared using HVOF thermal spraying at spray particle velocities varying from 540 m/s to 700 m/s. Mo-13.4Si-2.6B coatings were prepared using APS at particle velocities of 180 and 350 m/s. Residual stresses in the HVOF FeAl coatings were compressive, while stresses in the APS Mo-Si-B coatings were tensile. In both cases, residual stresses became more compressive with increasing spray particle velocity due to increased peening imparted by the spray particles. The hardness and elastic moduli of FeAl coatings also increased with increasing particle velocity, again due to an increased peening effect. For Mo-Si-B coatings, plasma spraying at 180 m/s resulted in significant oxidation of the spray particles and conversion of the T1 phase into amorphous silica and {alpha}-Mo. The T1 phase was retained after spraying at 350 m/s.

  6. AC 2012-3792: SYSTEMIC INTERVENTION: CONNECTING FORMAL AND INFORMAL EDUCATION EXPERIENCES FOR ENGAGING FE-

    E-Print Network [OSTI]

    FOR ENGAGING FE- MALE STUDENTS IN ELEMENTARY SCHOOL IN ENGINEERING Dr. Merredith D. Portsmore, Tufts University.A. English, B.S. mechanical engineering, M.A. education, and Ph.D. in engineering educa- tion). Her research interests focus on how children engage in constructing solutions to engineering design problems. Her

  7. Materials Research for Environment and Energy Hydrogen Embrittlement in Fe-Mn-C

    E-Print Network [OSTI]

    Cambridge, University of

    Materials Research for Environment and Energy - 1 - Hydrogen Embrittlement in Fe-Mn-C High Strength Seminar, May 23 #12;Materials Research for Environment and Energy - 2 - I had moved from NIMS to Kyushu.kaneaki@nims.go.jp> ********************* #12;Materials Research for Environment and Energy - 3 - #12;Materials Research for Environment

  8. Electronic spectroscopy of intermediates involved in the conversion of methane to methanol by FeO

    E-Print Network [OSTI]

    Metz, Ricardo B.

    Electronic spectroscopy of intermediates involved in the conversion of methane to methanol by Fe.1063/1.1448489 I. INTRODUCTION The direct oxidation of methane to an easily transport- able liquid such as methanol process and as the simplest model for alkane oxidation.1,2 Although no direct, efficient methane­methanol

  9. Calendar aging of a Graphite/LiFePO4 cell M. Kassem,a

    E-Print Network [OSTI]

    Boyer, Edmond

    1 Calendar aging of a Graphite/LiFePO4 cell M. Kassem,a J. Bernard,b R. Revel,b S. Pélissier,c F Rochelle, France Abstract Graphite/LFP commercial cells are stored under 3 different conditions increase is 70% or less. 1. Introduction Lithium-ion batteries are now the dominant rechargeable systems

  10. Cluster formula of Fe-containing Monel alloys with high corrosion-resistance

    SciTech Connect (OSTI)

    Li Baozeng; Gu Junjie [Key Lab of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Wang Qing, E-mail: wangq@dlut.edu.cn [Key Lab of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Ji Chunjun [College of Energy Source and Power, Dalian University of Science and Technology, Dalian, 116024 (China); Wang Yingmin; Qiang Jianbing [Key Lab of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Dong Chuang, E-mail: dong@dlut.edu.cn [Key Lab of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China)

    2012-06-15

    The cluster-plus-glue-atom model is applied in the composition interpretation of Monel alloys. This model considers ideal atomic nearest neighbor configurations among the constituent elements and has been used in understanding compositions of complex alloys like quasicrystals, amorphous alloys, and cupronickels. According to this model, any structure can be expressed by cluster formula [cluster](glue atom){sub x}, x denoting the number of glue atoms matching one cluster. According to this model, two groups of experimental composition series [Fe{sub 1}Ni{sub 12}]Cu{sub x} and [Fe{sub y}Ni{sub 12}]Cu{sub 5} were designed which fell close to conventional Fe-containing Monel alloys. The designed alloys after solution treatment plus water quenching, are monolithic FCC Ni-based solid solutions. Among them, the [Fe{sub 1}Ni{sub 12}]Cu{sub 5} alloy has the highest corrosion resistance in simulated sea water, and its performance is superior to that of industrial Monel 400 alloy. - Highlights: Black-Right-Pointing-Pointer A stable solid solution model is proposed using our 'cluster-plus-glue-atom model'. Black-Right-Pointing-Pointer This model is used to develop Monel corrosion resistant alloys. Black-Right-Pointing-Pointer Single FCC structure is easily retained. Black-Right-Pointing-Pointer The alloys show good corrosion properties. Black-Right-Pointing-Pointer This work contributes to the general understanding of engineering alloys.

  11. Crystal structure of the new FeSe1-x superconductor 

    E-Print Network [OSTI]

    Margadonna S.; McDonald M.T.; Kasperkiewicz K.; Mizuguchi Y.; Takano Y.; Fitch A.N.; Suard E.; Prassides K.; Takabayashi Y.

    2008-01-01

    The newly discovered superconductor FeSe1-x (x approximate to 0.08, T-c(onset) approximate to 13.5 K at ambient pressure rising to 27 K at 1.48 GPa) exhibits a structural phase transition from tetragonal to orthorhombic ...

  12. Modeling of the magnetic behavior of -Fe2O3 nanoparticles mineralized in ferritin

    E-Print Network [OSTI]

    Idzerda, Yves

    Modeling of the magnetic behavior of -Fe2O3 nanoparticles mineralized in ferritin Damon Resnick maghemite mineralized inside ferritin protein cages has been investigated with a vibrating sample be emptied of its con- tents and mineralized with a multitude of different materials, forming highly uniform

  13. Spin glass behavior in an interacting -Fe2O3 nanoparticle system D. Parker*1

    E-Print Network [OSTI]

    Boyer, Edmond

    - 1 - Spin glass behavior in an interacting -Fe2O3 nanoparticle system D. Parker*1 , V. Dupuis+2 glass behavior of a concentrated assembly of interacting maghemite nanoparticles and compare it to that of canonical atomic spin glass systems. ac versus temperature and frequency measurements show evidence

  14. A Biophysical Approach to Investigate the Human Fe-S Cluster Assembly Pathway 

    E-Print Network [OSTI]

    Fox, Nicholas G

    2014-06-02

    , and spectroscopic studies suggest conserved ISCU2 residue C104 is critical for FXN-based activation, whereas C35, C61, and C104, are all essential for Fe-S cluster biosynthesis. These results lead to an activation model in which FXN facilitates sulfur transfer from...

  15. Relation between thermal expansion and interstitial formation energy in pure Fe and Cr

    E-Print Network [OSTI]

    term, i.e. the contribution to the total energy from the valence electron density. Consequently we needRelation between thermal expansion and interstitial formation energy in pure Fe and Cr Janne Wallenius a,b,*, Pa¨r Olsson b , Christina Lagerstedt a a Department of Nuclear and Reactor Physics, KTH

  16. Using metal-organic templates to steer the growth of Fe and Co nanoclusters

    E-Print Network [OSTI]

    Brune, Harald

    Using metal-organic templates to steer the growth of Fe and Co nanoclusters R. Decker,1 U nanostructures are created using two-dimensional metal-organic honeycomb lattices as templates. They consist nucleate clusters at specific sites on top of the metal-organic lattices while leaving their hexagonal

  17. Low temperature MFM imaging of Fe??xV??xAl intermetallics 

    E-Print Network [OSTI]

    Nooner, Scott Lee

    1999-01-01

    temperature MFM system using two methods: by gluing Co particles onto the cantilever tip and by evaporating a Co thin film onto the cantilever tip. Samples of Fe[]V[]Al intermetallics (x = 0, x = 0.1, and x = 0.25) were polished and subsequently studied using...

  18. Corrosion performances in simulated body fluids and cytotoxicity evaluation of Fe-based bulk metallic glasses

    E-Print Network [OSTI]

    Zheng, Yufeng

    the use of BMGs as dental or knee-replacing biomaterials including Zr- based BMG systems [2­8] and Ti demonstrate that Fe based BMGs will open up a new path for the biomedical applications, especially in dental maximum diameter [16­18], which is a minimum requirement for the potential dental implant usage. We

  19. Point Defect Concentrations in Metastable Fe-C Alloys Clemens J. Forst,1,2

    E-Print Network [OSTI]

    Van Vliet, Krystyn J.

    steels, and by extension other technological materials created by or subjected to extreme environments steels are an important example where deformation behavior is intrinsically coupled to the lattice in the bcc-Fe matrix ranges from 0.3 at. % C upon 400 C annealing [7] to up to 5 at. % C in volumes

  20. Nonequivalence of the octahedral sites of cubic Fe3O4 magnetite Mark J. Wenzel*

    E-Print Network [OSTI]

    Steinle-Neumann, Gerd

    to be nonequivalent in their magnetic moments, charges, electric field gradients, and densities of states. We interpret this result to indicate either that 1 commonly used values of U may create an artificial nonequiva. INTRODUCTION The magnetic properties of lodestone, Fe3O4 magnetite, were first recorded more than 3500 years

  1. PHYSICAL REVIEW B 91, 094109 (2015) Polaronic deformation at the Fe2+/3+

    E-Print Network [OSTI]

    Schmidt, Wolf Gero

    2015-01-01

    of the oxygen ligands associated to the electronic capture at the Fe center that can be interpreted as due rise to a space charge redistribution and, consequently, to the building up of an electric field data storage stages via holographic recording [1] as well as holographic filters, demultiplexers

  2. Global optimization by coupled local minimizers and its application to FE model updating

    E-Print Network [OSTI]

    -3001 Heverlee, Belgium Received 2 August 2002; accepted 3 July 2003 Abstract Coupled local minimizersGlobal optimization by coupled local minimizers and its application to FE model updating Anne (CLM) is a new method applicable to global optimization of functions with multiple local minima. In CLM

  3. PII S0016-7037(00)00875-X Diffusion kinetics of Fe2

    E-Print Network [OSTI]

    Ganguly, Jibamitra

    PII S0016-7037(00)00875-X Diffusion kinetics of Fe2 and Mg in aluminous spinel: Experimental rates of terrestrial ultramafic rocks. Copyright © 2002 Elsevier Science Ltd 1. INTRODUCTION Diffusion data in spinel are of interest in a number of terrestrial and planetary problems. Ozawa (1984

  4. Anaerobic Benzene Oxidation in the Fe(III) Reduction Zone of

    E-Print Network [OSTI]

    Lovley, Derek

    Anaerobic Benzene Oxidation in the Fe(III) Reduction Zone of Petroleum-Contaminated Aquifers R O B North, University of Massachusetts, Amherst, Massachusetts 01003 The potential for anaerobic benzene. [14C]Benzene was not oxidized to 14CO2 at most sites examined, which is consistent with previous

  5. Precipitation in the Equiatomic High-Entropy Alloy CrMnFeCoNi

    E-Print Network [OSTI]

    Pickering, E. J.; Muñoz-Moreno, R.; Stone, H. J.; Jones, N. G.

    2015-11-02

    CrMnFeCoNi is widely considered to be an exemplar high-entropy alloy, which is stable as a single solid-solution phase at all temperatures below its melting point. Here, for the first time, the formation of two distinct types of Cr-rich precipitate...

  6. Uranium Immobilization through Fe(II) bio-oxidation: A Column study

    SciTech Connect (OSTI)

    Coates, John D.

    2009-09-14

    Current research on the bioremediation of heavy metals and radionuclides is focused on the ability of reducing organisms to use these metals as alternative electron acceptors in the absence of oxygen and thus precipitate them out of solution. However, many aspects of this proposed scheme need to be resolved, not the least of which is the time frame of the treatment process. Once treatment is complete and the electron donor addition is halted, the system will ultimately revert back to an oxic state and potentially result in the abiotic reoxidation and remobilization of the immobilized metals. In addition, the possibility exists that the presence of more electropositive electron acceptors such as nitrate or oxygen will also stimulate the biological oxidation and remobilization of these contaminants. The selective nitrate-dependent biooxidation of added Fe(II) may offer an effective means of “capping off” and completing the attenuation of these contaminants in a reducing environment making the contaminants less accessible to abiotic and biotic reactions and allowing the system to naturally revert to an oxic state. Our previous DOE-NABIR funded studies demonstrated that radionuclides such as uranium and cobalt are rapidly removed from solution during the biogenic formation of Fe(III)-oxides. In the case of uranium, X-ray spectroscopy analysis indicated that the uranium was in the hexavalent form (normally soluble) and was bound to the precipitated Fe(III)-oxides thus demonstrating the bioremediative potential of this process. We also demonstrated that nitrate-dependent Fe(II)- oxidizing bacteria are prevalent in the sediment and groundwater samples collected from sites 1 and 2 and the background site of the NABIR FRC in Oakridge, TN. However, all of these studies were performed in batch experiments in the laboratory with pure cultures and although a significant amount was learned about the microbiology of nitrate-dependent bio-oxidation of Fe(II), the effects of complex processes (such as advective flow) present in the natural environment are unknown. The objective of the current studies was to address some of these short-comings in an attempt to develop this bioremediative strategy into a robust, field applicable technology. This objective was approached by both pure culture studies investigating the mechanism of Fe(II) oxidation by nitrate reducing bacteria and examining the flow dynamics and microbial processes in advective flow columns amended with Fe(II) and nitrate over an extended period.

  7. Competing retention pathways of uranium upon reaction with Fe(II)

    SciTech Connect (OSTI)

    Massey, Michael S.; Lezama Pacheco, Juan S.; Jones, Morris; Ilton, Eugene S.; Cerrato, Jose M.; Bargar, John R.; Fendorf, Scott

    2014-10-01

    Biogeochemical retention processes, including adsorption, reductive precipitation, and incorporation into host minerals, are important in contaminant transport, remediation, and geologic deposition of uranium. Recent work has shown that U can become incorporated into iron (hydr)oxide minerals, with a key pathway arising from Fe(II)-induced transformation of ferrihydrite, (Fe(OH)3•nH2O) to goethite (?-FeO(OH)); this is a possible U retention mechanism in soils and sediments. Several key questions, however, remain unanswered regarding U incorporation into iron (hydr)oxides and this pathway’s contribution to U retention, including: (i) the competitiveness of U incorporation versus reduction to U(IV) and subsequent precipitation of UO2; (ii) the oxidation state of incorporated U; (iii) the effects of uranyl aqueous speciation on U incorporation; and, (iv) the mechanism of U incorporation. Here we use a series of batch reactions conducted at pH ~7, [U(VI)] from 1 to 170 ?M, [Fe(II)] from 0 to 3 mM, and [Ca] at 0 or 4 mM) coupled with spectroscopic examination of reaction products of Fe(II)-induced ferrihydrite transformation to address these outstanding questions. Uranium retention pathways were identified and quantified using extended x-ray absorption fine structure (EXAFS) spectroscopy, x-ray powder diffraction, x-ray photoelectron spectroscopy, and transmission electron microscopy. Analysis of EXAFS spectra showed that 14 to 89% of total U was incorporated into goethite, upon reaction with Fe(II) and ferrihydrite. Uranium incorporation was a particularly dominant retention pathway at U concentrations ? 50 ?M when either uranyl-carbonato or calcium-uranyl-carbonato complexes were dominant, accounting for 64 to 89% of total U. With increasing U(VI) and Fe(II) concentrations, U(VI) reduction to U(IV) became more prevalent, but U incorporation remained a functioning retention pathway. These findings highlight the potential importance of U(V) incorporation within iron oxides as a retention process of U across a wide range of biogeochemical environments and the sensitivity of uranium retention processes to operative (bio)geochemical conditions.

  8. Measuring Ages and Elemental Abundances from Unresolved Stellar Populations: Fe, Mg, C, N, and Ca

    E-Print Network [OSTI]

    Genevieve J. Graves; Ricardo P. Schiavon

    2008-03-10

    We present a method for determining mean light-weighted ages and abundances of Fe, Mg, C, N, and Ca, from medium resolution spectroscopy of unresolved stellar populations. The method, pioneered by Schiavon (2007), is implemented in a publicly available code called EZ_Ages. The method and error estimation are described, and the results tested for accuracy and consistency, by application to integrated spectra of well-known Galactic globular and open clusters. Ages and abundances from integrated light analysis agree with studies of resolved stars to within +/-0.1 dex for most clusters, and to within +/-0.2 dex for nearly all cases. The results are robust to the choice of Lick indices used in the fitting to within +/-0.1 dex, except for a few systematic deviations which are clearly categorized. The realism of our error estimates is checked through comparison with detailed Monte Carlo simulations. Finally, we apply EZ_Ages to the sample of galaxies presented in Thomas et al. (2005) and compare our derived values of age, [Fe/H], and [alpha/Fe] to their analysis. We find that [alpha/Fe] is very consistent between the two analyses, that ages are consistent for old (Age > 10 Gyr) populations, but show modest systematic differences at younger ages, and that [Fe/H] is fairly consistent, with small systematic differences related to the age systematics. Overall, EZ_Ages provides accurate estimates of fundamental parameters from medium resolution spectra of unresolved stellar populations in the old and intermediate-age regime, for the first time allowing quantitative estimates of the abundances of C, N, and Ca in these unresolved systems. The EZ_Ages code can be downloaded at http://www.ucolick.org/~graves/EZ_Ages.html

  9. A high temperature diffraction-resistance study of chalcopyrite, CuFeS{sub 2}

    SciTech Connect (OSTI)

    Engin, T.E.; Powell, A.V.; Hull, S.

    2011-08-15

    The electrical, magnetic and structural properties of synthetic chalcopyrite, CuFeS{sub 2}, have been studied up to 873 K using DC resistance measurements performed in-situ during neutron powder diffraction experiments. Under ambient conditions the material adopts the accepted structural model for CuFeS{sub 2} in the space group I4-bar 2d, with the magnetic moment of the Fe{sup 3+} cations aligned along [001]. The electrical resistivity is around 0.3 {Omega} cm under ambient conditions, consistent with semiconductor character, and decreases slightly with increase in temperature until a more abrupt fall occurs in the region 750-800 K. This abrupt change in resistivity is accompanied by a structural transition to a cubic zinc blende structured phase (space group F4-bar 3m) in which Cu{sup +} and Fe{sup 3+} cations are disordered over the same tetrahedral crystallographic sites and by a simultaneous loss of long-range magnetic order. The implications of these results are discussed in the context of previous studies of the chalcopyrite system. - Graphical abstract: Structural, magnetic and electrical properties of CuFeS{sub 2} to 873 K have been investigated using DC resistance measurements, performed in-situ during the collection of powder neutron diffraction data. Highlights: > Structural, magnetic and electronic properties are probed simultaneously. > A fall in resistivity at high temperatures is associated with cation disorder. > The order-disorder transition is accompanied by the loss of magnetic order. > The structural and magnetic phase transition is preceded by a 2-phase region. > Sulphur loss at high temperatures causes the phase transitions to be irreversible.

  10. Facilely preparation and microwave absorption properties of Fe{sub 3}O{sub 4} nanoparticles

    SciTech Connect (OSTI)

    Wang, Guiqin, E-mail: wanggq@dlut.edu.cn [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116085 (China); Chang, Yongfeng; Wang, Lifang; Liu, Lidong; Liu, Chao [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116085 (China)

    2013-03-15

    Highlights: ? A bran-new method is firstly used to fabricate Fe{sub 3}O{sub 4} nanoparticles. ? The detailed analysis of formation mechanism is discussed. ? The electromagnetic absorption properties are defined. ? The effect of nanometer-sized is considered for the excellent microwave absorption. - Abstract: The Fe{sub 3}O{sub 4} nanoparticles were prepared by a novel wet-chemical method which shows its highly synthesizing efficiency and controllability. A possible formation mechanism was also proposed to explain the synthesizing process. X-ray diffraction (XRD) and transmission electron microscope (TEM) were employed and yielded an examination of an average diameter of 77 nm of the as-synthesized Fe{sub 3}O{sub 4} nanoparticles with face-centered cubic structure. Vibrating sample magnetometer (VSM) and vector network analyzer were employed to measure the magnetic property and electromagnetic parameters of the nanoparticles, then reflection losses (RL (dB)) were calculated in the frequency range of 2–18 GHz. A large saturation magnetization (72.36 emu/g) and high coercivity (95 Oe) were determined and indicated that the Fe{sub 3}O{sub 4} nanoparticles own strong magnetic performance. Following simulation results showed that the lowest reflection loss of the sample was ?21.2 dB at 5.6 GHz with layer thickness of 6 mm. Effect of nanometer-sized further provided an explanation for the excellent microwave absorption behavior shown by the Fe{sub 3}O{sub 4} nanoparticles.

  11. Two-band modeling of -prime phase formation in Fe-Cr Pr Olsson,1 Janne Wallenius,1,2 Christophe Domain,3 Kai Nordlund,4 and Lorenzo Malerba5

    E-Print Network [OSTI]

    Nordlund, Kai

    of application to the Fe-Cr system, the basic component of ferritic-martensitic stainless steel. Fe-Cr forms

  12. Review: microbial mechanisms of accessing insoluble Fe(III) as an energy source Y-Su Luu and Juliana A. Ramsay*

    E-Print Network [OSTI]

    Ramsay, Juliana

    Review: microbial mechanisms of accessing insoluble Fe(III) as an energy source Y-Su Luu(III)-chelating compounds may alleviate the need for cell­oxide contact. These include microbially secreted compounds(III) to Fe(II) (Fenchel & Blackburn 1979). It is now known that microbial respiration with Fe(III) oxides

  13. 2446 IEEE TRANSACTIONS ON MAGNETICS, VOL. 46, NO. 6, JUNE 2010 Buffer Layers for Highly Ordered L10 FePt-Oxide Thin Film Granular

    E-Print Network [OSTI]

    Laughlin, David E.

    at moderate depo- sition temperatures. In most previous studies, a FePt-Oxide layer is directly deposited on a (001) textured MgO layer. By introducing a buffer layer in between the FePt-oxide layer and the MgO underlayer, we are able to substantially enhance the L10 ordering of the FePt-oxide layer while lowering

  14. Current-induced spin-orbit torque switching of perpendicularly magnetized Hf|CoFeB|MgO and Hf|CoFeB|TaO{sub x} structures

    SciTech Connect (OSTI)

    Akyol, Mustafa; Yu, Guoqiang; Alzate, Juan G.; Upadhyaya, Pramey; Li, Xiang; Wong, Kin L.; Khalili Amiri, Pedram; Wang, Kang L.; Ekicibil, Ahmet

    2015-04-20

    We study the effect of the oxide layer on current-induced perpendicular magnetization switching properties in Hf|CoFeB|MgO and Hf|CoFeB|TaO{sub x} tri-layers. The studied structures exhibit broken in-plane inversion symmetry due to a wedged CoFeB layer, resulting in a field-like spin-orbit torque (SOT), which can be quantified by a perpendicular (out-of-plane) effective magnetic field. A clear difference in the magnitude of this effective magnetic field (H{sub z}{sup FL}) was observed between these two structures. In particular, while the current-driven deterministic perpendicular magnetic switching was observed at zero magnetic bias field in Hf|CoFeB|MgO, an external magnetic field is necessary to switch the CoFeB layer deterministically in Hf|CoFeB|TaO{sub x}. Based on the experimental results, the SOT magnitude (H{sub z}{sup FL} per current density) in Hf|CoFeB|MgO (?14.12?Oe/10{sup 7} A cm{sup ?2}) was found to be almost 13× larger than that in Hf|CoFeB|TaO{sub x} (?1.05?Oe/10{sup 7} A cm{sup ?2}). The CoFeB thickness dependence of the magnetic switching behavior, and the resulting ?H{sub z}{sup FL} generated by in-plane currents are also investigated in this work.

  15. Wear behavior of the surface alloyed AISI 1020 steel with Fe-Nb-B by TIG welding technique

    SciTech Connect (OSTI)

    Kilinc, B. Durmaz, M.; Abakay, E.; Sen, U.; Sen, S.

    2015-03-30

    Weld overlay coatings also known as hardfacing is a method which involves melting of the alloys and solidification for applied coatings. Recently hardfacing by welding has become a commonly used technique for improvement of material performance in extreme (high temperature, impact/abrasion, erosion, etc.) conditions.In the present study, the coatings were produced from a mixture of ferrous niobium, ferrous boron and iron powders in the ranges of -45µm particle size with different ratio. Fe{sub 12}Nb{sub 5}B{sub 3} and Fe{sub 2}NbBalloys were coated on the AISI 1020 steel surface by TIG welding. The phases formed in the coated layer are Fe{sub 2}B, NbB{sub 2}, NbFeB and Fe0,2 Nb{sub 0,8} phases. The hardness of the presence phases are changing between 1689±85 HV{sub 0.01}, and 181±7 HV{sub 0.1}. Microstructural examinations were realized by optical and scanning electron microscopy. The wear and friction behaviors of Fe{sub 12}Nb{sub 5}B{sub 3} and Fe2NbB realized on the AISI 1020 steel were investigated by the technique of TIG welding by using ball-on-disk arrangement against alumina ball.

  16. Pervasive faint Fe XIX emission from a solar active region observed with EUNIS-13: Evidence for nanoflare heating

    SciTech Connect (OSTI)

    Brosius, Jeffrey W.; Daw, Adrian N.; Rabin, D. M.

    2014-08-01

    We present spatially resolved EUV spectroscopic measurements of pervasive, faint Fe XIX 592.2 Å line emission in an active region observed during the 2013 April 23 flight of the Extreme Ultraviolet Normal Incidence Spectrograph (EUNIS-13) sounding rocket instrument. With cooled detectors, high sensitivity, and high spectral resolution, EUNIS-13 resolves the lines of Fe XIX at 592.2 Å (formed at temperature T ? 8.9 MK) and Fe XII at 592.6 Å (T ? 1.6 MK). The Fe XIX line emission, observed over an area in excess of 4920 arcsec{sup 2} (2.58 × 10{sup 9} km{sup 2}, more than 60% of the active region), provides strong evidence for the nanoflare heating model of the solar corona. No GOES events occurred in the region less than 2 hr before the rocket flight, but a microflare was observed north and east of the region with RHESSI and EUNIS during the flight. The absence of significant upward velocities anywhere in the region, particularly the microflare, indicates that the pervasive Fe XIX emission is not propelled outward from the microflare site, but is most likely attributed to localized heating (not necessarily due to reconnection) consistent with the nanoflare heating model of the solar corona. Assuming ionization equilibrium we estimate Fe XIX/Fe XII emission measure ratios of ?0.076 just outside the AR core and ?0.59 in the core.

  17. The influence of microstructure on magnetic properties of nanocrystalline Fe-Pt-Nb-B permanent magnet ribbons

    SciTech Connect (OSTI)

    Randrianantoandro, N.; Greneche, J. M.; Crisan, A. D.; Crisan, O.; Marcin, J.; Kovac, J.; Hanko, J.; Skorvanek, I.; Svec, P.; Chrobak, A.

    2010-11-15

    A FePt-based hard-magnetic nanocomposite of exchange spring type was prepared by isothermal annealing of melt-spun Fe{sub 52}Pt{sub 28}Nb{sub 2}B{sub 18} (atomic percent) ribbons. The relationship between microstructure and magnetic properties was investigated by qualitative and quantitative structural analysis based on the x-ray diffraction, transmission electron microscopy, and {sup 57}Fe Moessbauer spectrometry on one hand and the superconducting quantum interference device magnetometry on the other hand. The microstructure consists of L1{sub 0}-FePt hard-magnetic grains (15-45 nm in diameter) dispersed in a soft magnetic medium composed by A1 FePt, Fe{sub 2}B, and boron-rich (FeB)PtNb remainder phase. The ribbons annealed at 700 deg. C for 1 h exhibit promising hard-magnetic properties at room temperature: M{sub r}/M{sub s}=0.69; H{sub c}=820 kA/m and (BH){sub max}=70 kJ/m{sup 3}. Strong exchange coupling between hard and soft magnetic phases was demonstrated by a smooth demagnetizing curve and positive {delta}M-peak in the Henkel plot. The magnetic properties measured from 5 to 750 K reveals that the hard characteristics remains rather stable up to 550 K, indicating a good prospect for the use of these permanent magnets in a wide temperature range.

  18. Analysis of the FeCrAl Accident Tolerant Fuel Concept Benefits during BWR Station Blackout Accidents

    SciTech Connect (OSTI)

    Robb, Kevin R

    2015-01-01

    Iron-chromium-aluminum (FeCrAl) alloys are being considered for fuel concepts with enhanced accident tolerance. FeCrAl alloys have very slow oxidation kinetics and good strength at high temperatures. FeCrAl could be used for fuel cladding in light water reactors and/or as channel box material in boiling water reactors (BWRs). To estimate the potential safety gains afforded by the FeCrAl concept, the MELCOR code was used to analyze a range of postulated station blackout severe accident scenarios in a BWR/4 reactor employing FeCrAl. The simulations utilize the most recently known thermophysical properties and oxidation kinetics for FeCrAl. Overall, when compared to the traditional Zircaloy-based cladding and channel box, the FeCrAl concept provides a few extra hours of time for operators to take mitigating actions and/or for evacuations to take place. A coolable core geometry is retained longer, enhancing the ability to stabilize an accident. Finally, due to the slower oxidation kinetics, substantially less hydrogen is generated, and the generation is delayed in time. This decreases the amount of non-condensable gases in containment and the potential for deflagrations to inhibit the accident response.

  19. Characterization and visible light photocatalytic mechanism of size-controlled BiFeO{sub 3} nanoparticles

    SciTech Connect (OSTI)

    He, Jian; Guo, Renqing; Fang, Liang; Dong, Wen; Zheng, Fengang; Shen, Mingrong

    2013-09-01

    Graphical abstract: BiFeO{sub 3} nanoparticles showed the size-dependent photocatalytic properties, and the corresponding photocatalytic mechanism for the pollutant degradation was proposed. - Highlights: • Size-controlled BiFeO{sub 3} nanoparticles were prepared by sol–gel method. • The hydroxyl radicals were the main reactive species responsible for the pollutant degradation. • BiFeO{sub 3} nanoparticles showed the size-dependent photocatalytic properties. - Abstract: BiFeO{sub 3} nanoparticles with controlled particle size were synthesized via sol–gel method. The samples were characterized by X-ray powder diffraction, transmission electron microscope, Raman spectra, nitrogen adsorption technique and UV–vis diffuse reflectance spectra. Photocatalytic activity of BiFeO{sub 3} nanoparticles was further examined by monitoring the degradation of Rhodamine B dye in an aqueous solution under visible light irradiation. Through the calculation of band position and a number of diagnostic experiments, the photocatalytic mechanism of BiFeO{sub 3} nanoparticles was proposed in this study. It was found that the hydroxyl radicals originated from the photogenerated electrons were the main reactive species responsible for the pollutant degradation. Moreover, with the variations of annealing temperature and time, the average crystallite size, specific surface area and crystallinity of BiFeO{sub 3} nanoparticles could be changed, which thus affected the photocatalytic activity of the corresponding samples.

  20. Observation of reversed hysteresis loops and negative coercivity in granular GaAs{endash}Fe hybrid structures

    SciTech Connect (OSTI)

    Fumagalli, P.; Sommer, G.; Lippitz, H.; Haneda, S.; Munekata, H.

    2001-06-01

    We have studied GaAs{endash}Fe granular magnetic-semiconductor hybrid structures by magneto-optic spectroscopy in a photon-energy range from 0.7 to 5 eV at temperatures from 7 to 300 K in magnetic fields up to 1.8 T. The structures have been grown by alternative molecular-beam deposition of GaAs and Fe. At the chosen substrate temperature of T{sub s}=580{degree}C the Fe precipitates into clusters of nanometer to submicron size which are in part ferromagnetically ordered at 300 K. The polar Kerr spectra at 300 and 7 K show for the hybrid structures with high Fe content a broad negative peak with a Kerr rotation of {minus}0.2{degree} at a photon energy of 0.9 eV. The spectral dependence is very similar to pure Fe. Looking at the polar Kerr hysteresis loops at 300 K, a striking behavior is found. The hysteresis loops are reversed, i.e., the magneto-optic hysteresis curves decrease faster when decreasing the fields than the situation is when closing the hysteresis loop on the way back. This peculiar behavior is discussed in the context of local exchange-bias like coupling between ferromagnetic Fe clusters and an antiferromagnetic FeAs surrounding. An alternative model of two superimposed Kerr hysteresis loops is proposed as well. {copyright} 2001 American Institute of Physics.

  1. Roles of Fe2+, Fe3+, and Cr3+ Surface Sites in the Oxidation of NO on the (Fe,Cr)3O4(1 1 1) Surface Termination of an ?-(Fe,Cr)2O3(0 0 0 1) Mixed Oxide

    SciTech Connect (OSTI)

    Henderson, Michael A.

    2014-10-01

    The oxidation and photooxidation reactions of nitric oxide were explored on a mixed Fe and Cr mixed oxide surface using temperature programmed desorption (TPD). The mixed oxide surface examined initially had a corundum (0001) structure with a nominal cation composition of 75% Fe and 25% Cr, but after sputter/anneal cleaning was transformed into a magnetite-like (111) surface structure enriched with Cr (~40%). TPD studies of nitric oxide on the (Fe,Cr)3O4(111) surface revealed two main desorption states at 220 and 370 K, along with a third minor desorption state at ~310 K. Similarly, O2 TPD occurred in two main TPD states (100 and 230 K) and a minor state (155 K). The more strongly and weakly bound NO and O2 molecules were assigned to adsorption at Fe2+ and Fe3+ sites, respectively, with the minor desorption states assigned to Cr3+ sites. No thermal decomposition or surface chemistry was detected in TPD for adsorbed NO (e.g., no N2 or N2O formation), whereas ~10% of the adsorbed O2 irreversibly dissociated at Fe2+ sites. These dissociated oxygen species did not react with coadsorbed NO, but instead blocked NO adsorption at the Fe2+ sites, but had no effect on NO adsorption at Fe3+ sites. In contrast, NO reacted with preadsorbed O2 molecules to generate an adsorbed nitrate/nitrite species that decomposed in TPD to liberate NO at 425 K, leaving an O atom on the surface. Coadsorption of 15N18O with 16O2 suggests the oxidized species was a nitrate based on the detected level of oxygen scrambling. Preadsorption of O2 was required for nitrate formation as preadsorbed NO blocked both O2 adsorption and the oxidation reaction. Irradiation of adsorbed NO with 460 nm light at 40 K resulted in rapid photodesorption of NO without generation of any new surface species. Irradiation of the coadsorbed NO+O2 system did not promote additional NO oxidation, but limited the extent of thermal NO oxidation (in subsequent TPD) by photodepleting the surface of adsorbed NO. Preheating the NO+O2 adlayer to 250 K prior to 460 nm light irradiation restored the level of thermal NO oxidation, revealing both that thermal activation is required for NO oxidation on the (Fe,Cr)3O4(111) surface and that the nitrate product was insensitive to 460 nm light. The author thanks Drs. Sara Chamberlin and Scott Chambers for supplying the film used in this work. This work was supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for DOE by Battelle. The research was performed using EMSL, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory.

  2. 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 0FeO{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.

  3. Bacterial Pu(V) reduction in the absence and presence of Fe(III)?NTA: modeling and experimental approach

    SciTech Connect (OSTI)

    Deo, Randhir P.; Rittmann, Bruce E.; Reed, Donald T. (AZU); (Guam); (LANL)

    2013-01-10

    Plutonium (Pu), a key contaminant at sites associated with the manufacture of nuclear weapons and with nuclear-energy wastes, can be precipitated to 'immobilized' plutonium phases in systems that promote bioreduction. Ferric iron (Fe{sup 3+}) is often present in contaminated sites, and its bioreduction to ferrous iron (Fe{sup 2+}) may be involved in the reduction of Pu to forms that precipitate. Alternately, Pu can be reduced directly by the bacteria. Besides Fe, contaminated sites often contain strong complexing ligands, such as nitrilotriacetic acid (NTA). We used biogeochemical modeling to interpret the experimental fate of Pu in the absence and presence of ferric iron (Fe{sup 3+}) and NTA under anaerobic conditions. In all cases, Shewanella alga BrY (S. alga) reduced Pu(V)(PuO{sub 2}{sup +}) to Pu(III), and experimental evidence indicates that Pu(III) precipitated as PuPO{sub 4(am)}. In the absence of Fe{sup 3+} and NTA, reduction of PuO{sub 2}{sup +} was directly biotic, but modeling simulations support that PuO{sub 2}{sup +} reduction in the presence of Fe{sup 3+} and NTA was due to an abiotic stepwise reduction of PuO{sub 2}{sup +} to Pu{sup 4+}, followed by reduction of Pu{sup 4+} to Pu{sup 3+}, both through biogenically produced Fe{sup 2+}. This means that PuO{sub 2}{sup +} reduction was slowed by first having Fe{sup 3+} reduced to Fe{sup 2+}. Modeling results also show that the degree of PuPO{sub 4(am)} precipitation depends on the NTA concentration. While precipitation out-competes complexation when NTA is present at the same or lower concentration than Pu, excess NTA can prevent precipitation of PuPO{sub 4(am)}.

  4. 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.

  5. Graphene as a surfactant for metal growth on solid surfaces: Fe on graphene/SiC(0001)

    SciTech Connect (OSTI)

    Wang, Zhou-jun; Dong, Aiyi; Wei, Mingming; Fu, Qiang, E-mail: qfu@dicp.ac.cn; Bao, Xinhe [State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, The Chinese Academy of Sciences, Dalian 116023 (China)

    2014-05-05

    X-ray photoelectron spectroscopic and scanning tunneling microscopic results demonstrate that annealing of Fe/carbon-rich 6H-SiC(0001) surface between 650 and 750?°C leads to Fe intercalation under the surface carbon layer. Accompanied with the metal intercalation, the carbon nanomesh surface was transformed into a graphene surface. Moreover, the formed graphene layers always float out to the topmost surface even after deposition of more than 10 monolayer Fe, acting as a surfactant. Using graphene as the surfactant may not only promote the 2D growth but also can improve the film performance considering that graphene is stable and robust.

  6. The development of low cost LiFePO4-based high power lithium-ion batteries

    SciTech Connect (OSTI)

    Shim, Joongpyo; Sierra, Azucena; Striebel, Kathryn A.

    2003-11-25

    The cycling performance of low-cost LiFePO4-based high-power lithium-ion cells was investigated and the components were analyzed after cycling to determine capacity fade mechanisms. Pouch type LiFePO4/natural graphite cells were assembled and evaluated by constant C/2 cycling, pulse-power and impedance measurements. From post-test electrochemical analysis after cycling, active materials, LiFePO4 and natural graphite, showed no degradation structurally or electrochemically. The main reasons for the capacity fade of cell were lithium inventory loss by side reaction and possible lithium deposition on the anode.

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

    SciTech Connect (OSTI)

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

    1984-01-01

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

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

    SciTech Connect (OSTI)

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

    1985-04-15

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

  9. 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; Chi, Songxue; Ueda, Yutaka; Yoshizawa, Hideki; Sato, Taku J.

    2015-05-01

    We investigated the iron-based ladder compounds (Ba,Cs)Fe?Se?. Their parent compounds BaFe?Se? and CsFe?Se? 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 BaFe?Se? is drastically suppressed with Cs doping. In contrast, stripe magnetism observed in CsFe?Se? is not so fragile against Ba doping. A new type of magnetic structure appears in intermediate compositions, which is similar to stripe magnetism of CsFe?Se?, but interladder spin configuration is different. Intermediate compounds show insulating behavior, nevertheless a finite T-linear contribution in specific heat was obtained at low temperatures.

  10. 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)Fe?Se?. Their parent compounds BaFe?Se? and CsFe?Se? 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 BaFe?Se? is drastically suppressed with Cs doping. In contrast, stripe magnetism observed in CsFe?Se? is not so fragile against Ba doping. A new type of magnetic structure appears in intermediate compositions, which is similar to stripe magnetism of CsFe?Se?, 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

  11. Influence of stoichiometry and growth temperature on the crystal structure and magnetic properties of epitaxial L1{sub 0} Fe-Pd (001) films

    SciTech Connect (OSTI)

    Chang, Y. C. [Department of Material Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan (China); National Synchrotron Radiation Research Center, Hsinchu 30077, Taiwan (China); Hsiao, S. N., E-mail: pmami.hsiao@gmail.com; Liu, Y. T.; Lee, H. Y., E-mail: hylee@nsrrc.org.tw [National Synchrotron Radiation Research Center, Hsinchu 30077, Taiwan (China); Liu, S. H.; Chen, S. K. [Department of Material Science and Engineering, Feng Chia University, Taichung 407, Taiwan (China); Sun, A. C. [Department of Chemical Engineering and Material Science, YunZe University, Chungli 135, Taiwan (China); Dhu, J. G., E-mail: jgdhu@nthu.edu.tw [Department of Material Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan (China)

    2014-05-07

    To investigate the crystallographic structure and the magnetic properties as a function of chemical composition (40–62 at. %) and substrate temperature (T{sub s}?=?300–550?°C), we fabricated epitaxial FePd films of thickness 20?±?2?nm by sputtering on MgO (100) single-crystal substrates. The ordering parameter, measured by x-ray diffraction with synchrotron radiation, and the perpendicular anisotropy of the Fe{sub 54}Pt{sub 46} films increased with increasing substrate temperature. For FePd films (T{sub s}?=?550?°C) with varied Fe content, a direct correlation between the ordering parameter and the magnetocrystalline anisotropy field is found. The greatest ordering parameter, 0.84, and magnetocrystalline anisotropy field, ?20 kOe, were obtained for FePd films of Fe concentration 54 at. %, indicating that an off-stoichiometric L1{sub 0} FePd might be preferable for engineering and applications.

  12. Effect of FeO-content and potentials for quality improvements of iron ore pellets

    SciTech Connect (OSTI)

    Kortmann, H.A.; Mertins, E.; Ritz, V.J. [Studiengesellschaft fuer Eisenerzaufbereitung, Liebenburg-Othfresen (Germany)

    1995-12-01

    The FeO-content strongly influences the physical and metallurgical properties of iron ore pellets. A wide range of FeO-contents within the pellet deliveries to the Germany market is evaluated. Investigations include the effect of pellet size. The paper concludes potentials for quality improvement of iron ore pellets. Most of the German blast furnaces are operated with high injection rates either of oil or of coal resulting in a decrease of coke consumption down to a level of about 300 kg/t hot metal. As the retention time of the burden increases, blast furnace operators demand higher quality burden material, basically with respect to strength before and during reduction.

  13. Magnetic properties on the surface of FeAl stripes induced by nanosecond pulsed laser irradiation

    SciTech Connect (OSTI)

    Kaiju, H., E-mail: kaiju@es.hokudai.ac.jp; Kondo, K.; Ishibashi, A. [Laboratory of Nano-Structure Physics, Research Institute for Electronic Science, Hokkaido University, Sapporo, Hokkaido 001-0020 (Japan); Yoshida, Y. [Center for Advanced Research of Energy and Materials, Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628 (Japan); Creative Research Institution Sousei, Hokkaido University, Sapporo, Hokkaido 001-0021 (Japan); Watanabe, S. [Center for Advanced Research of Energy and Materials, Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628 (Japan); Yoshimi, K. [Graduate School of Engineering, Tohoku University, Sendai, Miyagi 980-8579 (Japan)

    2014-05-07

    We demonstrate the formation of magnetic nanostripes on the surface of Fe{sub 52}Al{sub 48} induced by nanosecond pulsed laser irradiation and investigate their magnetic properties. The magnetic stripe consists of a disordered A2 phase of Fe-Al alloys with Al-oxide along the [110] direction on the (111)-oriented plane. According to the focused magneto-optical Kerr effect measurement, the coercive force of the magnetic stripe obeys the 1/cos?? law, where ? is the field rotation angle estimated from the stripe direction. Also, the jump field can be observed in the magnetic hysteresis loop. These results indicate that the magnetization reversal in the magnetic stripe originates from the domain pinning, showing that the magnetization rotates incoherently.

  14. Ab initio study of structural, electronic, magnetic alloys: XTiSb (X = Co, Ni and Fe)

    SciTech Connect (OSTI)

    Ibrir, M. Berri, S.; Lakel, S.; Alleg, S.; Bensalem, R.

    2015-03-30

    Structural, electronic and magnetic properties of three semi-Heusler compounds of CoTiSb, NiTiSb and FeTiSb were calculated by the method (FP-LAPW) which is based on the DFT code WIEN2k. We used the generalized gradient approximation (GGA (06)) for the term of the potential exchange and correlation (XC) to calculate structural properties, electronic properties and magnetic properties. Structural properties obtained as the lattice parameter are in good agreement with the experimental results available for the electronic and magnetic properties was that: CoTiSb is a semiconductor NiTiSb is a metal and FeTiSb is a half-metal ferromagnetic.

  15. Three-terminal magnetic tunneling junction device with perpendicular anisotropy CoFeB sensing layer

    SciTech Connect (OSTI)

    Honjo, H. Nebashi, R.; Tokutome, K.; Miura, S.; Sakimura, N.; Sugibayashi, T.; Fukami, S.; Kinoshita, K.; Murahata, M.; Kasai, N.; Ishihara, K.; Ohno, H.

    2014-05-07

    We demonstrated read and write characteristics of a three terminal memory device with a perpendicular anisotropy-free layer of a strip of [Co/Ni] and a low-switching perpendicular-anisotropy CoFeB/MgO sensing layer. This new design of the cell results in a small cell area. The switching magnetic field of the sensing layer can be decreased by changing sputtering gas for the Ta-cap from Ar to Kr. An electron energy-loss spectroscopy analysis of the cross-section of the magnetic tunneling junction (MTJ) revealed that the boron content in CoFeB with a Kr-sputtered Ta-cap was smaller than that with an Ar-sputtered one. A change in resistance for the MTJ was observed that corresponded to the magnetic switching of the Co/Ni wire and its magnetoresistance ratio and critical current were 90% and 0.8?mA, respectively.

  16. Evidence for Nodal Superconductivity in LaFePO from Scanning SQUID Susceptometry

    SciTech Connect (OSTI)

    Hicks, Clifford W.; Lippman, Thomas M.; Huber, Martin E.; Analytis, James G.; Chu, Jiun-Haw; Erickson, Ann S.; Fisher, Ian R.; Moler, Kathryn A.; /Stanford U., Geballe Lab. /SLAC

    2009-04-13

    We measure changes in the penetration depth {lambda} of the T{sub c} {approx} 6 K superconductor LaFePO. In the process scanning SQUID susceptometry is demonstrated as a technique for accurately measuring local temperature-dependent changes in {lambda}, making it ideal for studying early or difficult-to-grow materials. {lambda} of LaFePO is found to vary linearly with temperature from 0.36 to {approx} 2 K, with a slope of 143 {+-} 15 {angstrom}/K, suggesting line nodes in the superconducting order parameter. The linear dependence up to {approx} T{sub c}/3 is similar to the cuprate superconductors, indicating well-developed nodes.

  17. Magnetic order of the iron spins in NdFeAsO

    SciTech Connect (OSTI)

    Chen, Ying [National Institute of Standards and Technology (NIST); Lynn, J. W. [National Institute of Standards and Technology (NIST); Li, J. [National Institute of Standards and Technology (NIST); Li, G. [Beijing National Laboratroy for Condensed Matter Physics, Institute of Physics; Chen, G. F, [Beijing National Laboratroy for Condensed Matter Physics, Institute of Physics; Luo, J. L. [Chinese Academy of Sciences; Wang, N. L. [Chinese Academy of Sciences; Dai, Pengcheng [ORNL; de la Cruz, Clarina [University of Tennessee, Knoxville (UTK); Mook Jr, Herbert A [ORNL

    2008-09-01

    Polanzed and unpolarized neutron-diffraction mcasurements have bcr.:n carncd OUI to investigate the iron magnetIC order in undoped NdFeAsO. Antiferromagnctic order is observed bela" 141(6) K. which is in close proXtrlllty to the structural dlslonlon observed in thiS malena\\. The magnetl<: structure consists of chains of parallel spins that arc arrant;ed antiparallel between chams. which is Ihe same m-plane spin arrangement as observed in all the other iron oxypnictidc matcrials. Nearest-neighbor spins along the c a"is are antiparallellike LaFeAsO. The ordered momcnt is 0.25(7) /LR, which is the smallest moment found so far In these systems. 001: 10.1103/Ph}sRc"B.7S.064515 PACS numher(s): 74.25.Ha. 74.70.Dd. 75.25.+z. 75.40.Cx

  18. Thermodynamic modeling and experimental validation of the Fe-Al-Ni-Cr-Mo alloy system

    SciTech Connect (OSTI)

    Teng, Zhenke; Zhang, F; Miller, Michael K; Liu, Chain T; Huang, Shenyan; Chou, Y.T.; Tien, R; Chang, Y A; Liaw, Peter K

    2012-01-01

    NiAl-type precipitate-strengthened ferritic steels have been known as potential materials for the steam turbine applications. In this study, thermodynamic descriptions of the B2-NiAl type nano-scaled precipitates and body-centered-cubic (BCC) Fe matrix phase for four alloys based on the Fe-Al-Ni-Cr-Mo system were developed as a function of the alloy composition at the aging temperature. The calculated phase structure, composition, and volume fraction were validated by the experimental investigations using synchrotron X-ray diffraction and atom probe tomography. With the ability to accurately predict the key microstructural features related to the mechanical properties in a given alloy system, the established thermodynamic model in the current study may significantly accelerate the alloy design process of the NiAl-strengthened ferritic steels.

  19. Electronic structure reconstruction across the antiferromagnetic transition in TaFe????Te? spin ladder

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

    Xu, Min; Wang, Li -Min; Peng, Rui; Ge, Qing -Qin; Chen, Fei; Ye, Zi -Rong; Zhang, Yan; Chen, Su -Di; Xia, Miao; Liu, Rong -Hua; et al

    2015-02-01

    With angle-resolved photoemission spectroscopy, we studied the electronic structure of TaFe????Te?, a two-leg spin ladder compound with a novel antiferromagnetic ground state. Quasi-two-dimensional Fermi surface is observed, with sizable inter-ladder hopping. Moreover, instead of observing an energy gap at the Fermi surface in the antiferromagnetic state, we observed the shifts of various bands. Combining these observations with density-functional-theory calculations, we propose that the large scale reconstruction of the electronic structure, caused by the interactions between coexisting itinerant electrons and local moments, is most likely the driving force of the magnetic transition. Thus TaFe????Te? serves as a simpler platform that containsmore »similar ingredients as the parent compounds of iron-based superconductors.« less

  20. Synthesis, characterization and physical properties of Al-Cu-Fe quasicrystalline plasma sprayed coatings

    SciTech Connect (OSTI)

    Daniel, S.

    1995-11-09

    Our lab has been working with plasma spraying of both high pressure gas atomized (HPGA) and cast and crushed quasicrystal powders. A major component of this research includes comparative studies of PAS coatings formed with starting powders prepared by both techniques. In addition, a thorough investigation of the effects of starting powder particle size on coating microstructure is included. During the course of the overall research, an interest developed in forming Al-Cu-Fe materials with finer grain sizes. Therefore, a brief study was performed to characterize the effect of adding boron to Al-Cu-Fe materials prepared by different techniques. In addition to characterizing the microstructural features of the above materials, oxidation and wear behavior was also examined.

  1. Combustion of Bulk 84% Fe/16% KCIO{sub 4} heat powder

    SciTech Connect (OSTI)

    Nissen, M.; Guidotti, R.A.; Berry, B.

    1996-05-01

    Fe/KClO{sub 4} pyrotechnic mixtures are used in thermal batteries to provide the heat necessary to bring the battery stack to operating temperatures of 550 to 600 C. This heat source is normally used as discs pressed from bulk powder. To evaluate the consequences associated with unexpected ignition of large amounts of heat powder, combustion of 84% Fe/16% KClO{sub 4} heat powders was conducted for various scenarios under controlled conditions and the response documented. Increasing amounts of heat powder--up to 8 lbs--were ignited in both unconfined and confined (sealed) containers in a remote area. The containers were thermocoupled and the resulting burning filmed with a standard video camera, high-speed (1,000 frames/s) film and video cameras, and an infrared video camera. A 20- minute video of the burning under the various conditions is presented.

  2. Surface driven effects on magnetic properties of antiferromagnetic LaFeO{sub 3} nanocrystalline ferrite

    SciTech Connect (OSTI)

    Sendil Kumar, A. E-mail: anilb42@gmail.com; Manivel Raja, M.; Bhatnagar, Anil K. E-mail: anilb42@gmail.com

    2014-09-21

    LaFeO{sub 3} nanocrystalline ferrites were synthesized through sol-gel method in different size distributions and the effect of finite size on magnetic properties is investigated. Results of magnetization and Mössbauer measurements show that superparamagnetism and weak ferromagnetic behavior in some of the size distributions. The origin of the superparamagnetism is from fine particles similar to ferromagnetic single domains and the weak ferromagnetism comes from surface spin disorder caused by Dzyaloshinskii-Moriya interaction. The magnetic ground state of LaFeO{sub 3} nanoparticles differs from that of bulk, and the ground state is dictated by the finite size effect because density of states depends on the dimensionality of the sample.

  3. Decay of neutron-rich Mn nuclides and deformation of heavy Fe isotopes

    E-Print Network [OSTI]

    M. Hannawald; T. Kautzsch; A. Woehr; W. B. Walters; K. -L. Kratz; V. N. Fedoseyev; V. L. Mishin; W. Boehmer; B. Pfeiffer; V. Sebastian; Y. Jading; U. Koester; J. Lettry; H. L. Ravn; the ISOLDE Collaboration

    1998-12-21

    The use of chemically selective laser ionization combined with beta-delayed neutron counting at CERN/ISOLDE has permitted identification and half-life measurements for 623-ms Mn-61 up through 14-ms Mn-69. The measured half-lives are found to be significantly longer near N=40 than the values calculated with a QRPA shell model using ground-state deformations from the FRDM and ETFSI models. Gamma-ray singles and coincidence spectroscopy has been performed for Mn-64 and Mn-66 decays to levels of Fe-64 and Fe-66, revealing a significant drop in the energy of the first 2+ state in these nuclides that suggests an unanticipated increase in collectivity near N=40.

  4. THE ORIGIN OF LOW [?/Fe] RATIOS IN EXTREMELY METAL-POOR STARS

    SciTech Connect (OSTI)

    Kobayashi, Chiaki [School of Physics, Astronomy and Mathematics, Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield AL10 9AB (United Kingdom); Ishigaki, Miho N.; Tominaga, Nozomu; Nomoto, Ken'ichi, E-mail: c.kobayashi@herts.ac.uk [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan)

    2014-04-10

    We show that the low ratios of ? elements (Mg, Si, and Ca) to Fe recently found for a small fraction of extremely metal-poor stars can be naturally explained with the nucleosynthesis yields of core-collapse supernovae, i.e., 13-25 M {sub ?} supernovae, or hypernovae. For the case without carbon enhancement, the ejected iron mass is normal, consistent with observed light curves and spectra of nearby supernovae. On the other hand, the carbon enhancement requires much smaller iron production, and the low [?/Fe] of carbon-enhanced metal-poor stars can also be reproduced with 13-25 M {sub ?} faint supernovae or faint hypernovae. Iron-peak element abundances, in particular Zn abundances, are important to put further constraints on the enrichment sources from galactic archaeology surveys.

  5. Origin of room temperature ferromagnetic moment in Rh-rich Rh/Fe multilayer thin films

    E-Print Network [OSTI]

    Laughlin, David E.

    doing the magnetic measure- ments, a constant in-plane field of 0.8 T was applied to satu- rate the film in the antiferromagnetic AFM to ferromagnetic FM state on heating above 350 K and switch back on cooling, with a hysteresis. This property makes FeRh a very attractive choice as a write-assist layer material for low temperature heat

  6. Al-Ca and Al-Fe metal-metal composite strength, conductivity, and microstructure relationships

    SciTech Connect (OSTI)

    Kim, Hyong June

    2011-12-01

    Deformation processed metal-metal composites (DMMC’s) are composites formed by mechanical working (i.e., rolling, swaging, or wire drawing) of two-phase, ductile metal mixtures. Since both the matrix and reinforcing phase are ductile metals, the composites can be heavily deformed to reduce the thickness and spacing of the two phases. Recent studies have shown that heavily drawn DMMCs can achieve anomalously high strength and outstanding combinations of strength and conductivity. In this study, Al-Fe wire composite with 0.07, 0.1, and 0.2 volume fractions of Fe filaments and Al-Ca wire composite with 0.03, 0.06, and 0.09 volume fractions of Ca filaments were produced in situ, and their mechanical properties were measured as a function of deformation true strain. The Al-Fe composites displayed limited deformation of the Fe phase even at high true strains, resulting in little strengthening effect in those composites. Al-9vol%Ca wire was deformed to a deformation true strain of 13.76. The resulting Ca second-phase filaments were deformed to thicknesses on the order of one micrometer. The ultimate tensile strength increased exponentially with increasing deformation true strain, reaching a value of 197 MPa at a true strain of 13.76. This value is 2.5 times higher than the value predicted by the rule of mixtures. A quantitative relationship between UTS and deformation true strain was determined. X-ray diffraction data on transformation of Al + Ca microstructures to Al + various Al-Ca intermetallic compounds were obtained at the Advanced Photon Source at Argonne National Laboratory. Electrical conductivity was measured over a range of true strains and post-deformation heat treatment schedules.

  7. Magnetotransport measurements of current induced effective fields in Ta/CoFeB/MgO

    SciTech Connect (OSTI)

    Zhang, Chaoliang; Yamanouchi, Michihiko Ikeda, Shoji; Center for Spintronics Integrated Systems, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 ; Sato, Hideo; Fukami, Shunsuke; Matsukura, Fumihiro; Ohno, Hideo; Center for Spintronics Integrated Systems, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577; WPI Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577

    2013-12-23

    We evaluate current-induced effective magnetic fields in perpendicularly magnetized Ta/CoFeB/MgO structures from the external magnetic field angle dependence of the Hall resistance. We confirm the presence of two components of effective fields. The dependence of their magnitudes on Ta thickness implies that both components are related to the spin current in Ta layer generated by the spin Hall effect.

  8. Role of Trapping Impurities on He Desorption and Clustering in Irradiated a-Fe

    SciTech Connect (OSTI)

    Ortiz, Christophe J.; Caturla, Maria Jose; Fu, Chu Chun; Willaime, Francois

    2008-07-01

    It is well-known that impurities affect the migration of intrinsic point defects in metals. For instance, carbon is a common impurity in Fe that significantly retards diffusion of vacancies. Under fusion irradiation conditions, high levels of He are produced by transmutation reactions. This element strongly interacts with vacancies produced during irradiation and agglomerate into stable He-vacancy clusters that can deteriorate the mechanical properties of the material. A physically-based model accounting for the interactions between He, point defects (interstitials and vacancies) and trapping impurities is therefore necessary to understand and predict damage evolution in Fe. We have used a multi-scale approach to predict the evolution of He in the presence of impurities in irradiated Fe. Density Functional Theory (DFT) calculations were performed to investigate the migration mechanisms and to determine the activation energies of the different atomistic processes. The influence of impurities - such as carbon - on the binding energies of small He-vacancy clusters was also studied. Using the information obtained by DFT a physically-based model was developed and implemented in a kinetic Monte Carlo (kMC) code to follow the evolution of He in Fe. In addition, a model based on the rate theory (RT) was developed in order to achieve larger simulation times and volumes. Results obtained with this model, which is based on a mean field approximation are compared to those obtained with kMC. Using this multi-scale approach, the simulation results are used to interpret the different stages of thermal He desorption experiments and to determine the predominant migration mechanism. The influence of impurities which affect the diffusion of point defects or modify the binding energies of He-vacancy type clusters is also studied. (authors)

  9. EMPIRICAL DETERMINATION OF EINSTEIN A-COEFFICIENT RATIOS OF BRIGHT [Fe II] LINES

    SciTech Connect (OSTI)

    Giannini, T.; Antoniucci, S.; Nisini, B.; Lorenzetti, D.; Alcalá, J. M.; Bacciotti, F.; Podio, L.; Bonito, R.; Stelzer, B.

    2015-01-01

    The Einstein spontaneous rates (A-coefficients) of Fe{sup +} lines have been computed by several authors with results that differ from each other by up to 40%. Consequently, models for line emissivities suffer from uncertainties that in turn affect the determination of the physical conditions at the base of line excitation. We provide an empirical determination of the A-coefficient ratios of bright [Fe II] lines that would represent both a valid benchmark for theoretical computations and a reference for the physical interpretation of the observed lines. With the ESO-Very Large Telescope X-shooter instrument between 3000 Å and 24700 Å, we obtained a spectrum of the bright Herbig-Haro object HH 1. We detect around 100 [Fe II] lines, some of which with a signal-to-noise ratios ?100. Among these latter lines, we selected those emitted by the same level, whose dereddened intensity ratios are direct functions of the Einstein A-coefficient ratios. From the same X-shooter spectrum, we got an accurate estimate of the extinction toward HH 1 through intensity ratios of atomic species, H I  recombination lines and H{sub 2} ro-vibrational transitions. We provide seven reliable A-coefficient ratios between bright [Fe II] lines, which are compared with the literature determinations. In particular, the A-coefficient ratios involving the brightest near-infrared lines (?12570/?16440 and ?13209/?16440) are in better agreement with the predictions by the Quinet et al. relativistic Hartree-Fock model. However, none of the theoretical models predict A-coefficient ratios in agreement with all of our determinations. We also show that literature data of near-infrared intensity ratios better agree with our determinations than with theoretical expectations.

  10. Synthesis of pure, active, and fine NiFe?O? by aerosolization 

    E-Print Network [OSTI]

    Yu, Hsuan-Fu

    1989-01-01

    in water, a dilute aqueous solution of Ni(II) and Fe(III) nitrates was used to prepare as starting material to synthesize pure, active, and fine nickel ferrite powders. The pyrolysis temperature was varied from 450'C to 810'C. The final product.... As the pyrolysis temperature increased, sintering occurred, larger particles and broader size distribution were obtained, and the degree of crystallinity of nickel ferrite increased. The products at pyrolysis temperatures of 660'C and above exhibited magnetic...

  11. TECHNICAL ARTICLE Laboratory and Field-scale Evaluation of Low-pH Fe(II)

    E-Print Network [OSTI]

    Burgos, William

    and build treatment systems for low-pH acid mine drainage (AMD) discharges. Keywords Acid mine drainage Á Fe are neutralized with limestone. In the pH range typical of acidic Appalachian mine drainage (2.5­4.5) (Cravotta et,950 ha. The borehole discharge averages approximately 63 L/s of acidic (pH 4, 230 mg/L acidity) mine

  12. Propagating spectroscopy of backward volume spin waves in a metallic FeNi film

    SciTech Connect (OSTI)

    Sato, N.; Ishida, N.; Kawakami, T.; Sekiguchi, K.

    2014-01-20

    We report a propagating spin wave spectroscopy for a magnetostatic backward volume spin wave in a metallic Fe{sub 19}Ni{sub 81} film. We show that the mutual-inductance between two independent antennas detects a small but clear propagation signal of backward volume spin waves. All experimental data are consistent with the time-domain propagating spin-wave spectroscopy. The control of propagating backward spin wave enables to realize the miniaturize spin-wave circuit.

  13. Electronic structure of Fe{sub 3}Si on Si(100) substrates

    SciTech Connect (OSTI)

    Lal, Chhagan, E-mail: clsaini52@gmail.com [Centre for Non-Conventional Energy Resources, 14-Vigyan Bhavan, University of Rajasthan, Jaipur-302004 (India); Synchrotron S.C.p.A., SS-14 km, 163.5, in Area Science Park, 34149, Basovizza, Trieste (Italy); International Centre for Theoretical Physics (Italy); Di Santo, G.; Caputo, M.; Panighel, M.; Goldoni, A. [Synchrotron S.C.p.A., SS-14 km, 163.5, in Area Science Park, 34149, Basovizza, Trieste (Italy); Taleatu, B. A. [Department of Physics, Obafemi Awolowo University Ile-Ife (Nigeria); Jain, I. P. [Centre for Non-Conventional Energy Resources, 14-Vigyan Bhavan, University of Rajasthan, Jaipur-302004 (India)

    2014-04-24

    The improved performance of large-scale integrated circuits (LSIs) by the shrinking of devices is becoming difficult due to physical limitations. Here we report, the growth and formation of Fe{sub 3}Si on Si(100) and characterized by x-ray photoemission, UV photoemission and low energy electron diffraction to study the electronic structure. The results revealed that the DO{sub 3} phase formation is exist and photoemission results also support the electron diffraction outcome.

  14. SEMI-ANNUAL REPORTS FOR AMERICAN LNG MARKETING LLC, FE DKT. 15-19-LNG -

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterestedReplacement-2-AA-1 SECTION J APPENDIX A ADVANCE- FE DKT. NO.

  15. SEMI-ANNUAL REPORTS FOR ANNOVA LNG COMMON INFRASTRUCTURE, LLC - FE DKT. NO.

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterestedReplacement-2-AA-1 SECTION J APPENDIX A ADVANCE- FE DKT.

  16. SEMI-ANNUAL REPORTS FOR BARCA LNG - FTA - FE DKT. NO. 13-117-LNG - ORDER

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterestedReplacement-2-AA-1 SECTION J APPENDIX A ADVANCE- FE DKT.3365 | Department of

  17. SEMI-ANNUAL REPORTS FOR Cameron LNG, LLC - FE Dkt. No. 15-36-LNG - ORDER

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterestedReplacement-2-AA-1 SECTION J APPENDIX A ADVANCE- FE DKT.3365 |LIQUEFACTION,

  18. SEMI-ANNUAL REPORTS FOR JORDAN COVE ENERGY PROJECT, L.P. - FE DKT. NO.

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterestedReplacement-2-AA-1 SECTION J APPENDIX A ADVANCE- FE DKT.3365NO.

  19. SEMI-ANNUAL REPORTS FOR SABINE PASS LIQUEFACTION, LLC - FE DKT. NO.

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterestedReplacement-2-AA-1 SECTION J APPENDIX A ADVANCE- FE

  20. Designing materials for energy storage with high power and energy density : LiFePO? cathode material

    E-Print Network [OSTI]

    Kang, Byoungwoo

    2010-01-01

    LiFePO? has drawn a lot of attention as a cathode material in lithium rechargeable batteries because its structural and thermal stability, its inexpensive cost, and environmental friendliness meet the requirements of power ...