National Library of Energy BETA

Sample records for bh fe ru

  1. Superior destabilization e ects of LiBH4 with the addition of nano-sized nickel ferrite NiFe2O4

    E-Print Network [OSTI]

    Volinsky, Alex A.

    BH4. In this paper the e ects of nano-sized nickel ferrite (NiFe2O4) on the hydrogen storage innovative hydrogen storage systems. Solid hydrogen storage materials have recently emerged as a new solution considerable attention for potential hydrogen storage due to high hydrogen reserve mass and light weight.5

  2. Chemical pressure tuning of URu?Si? via isoelectronic substitution of Ru with Fe

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

    Das, Pinaki; Kanchanavatee, N.; Helton, J. S.; Huang, K.; Baumbach, R. E.; Bauer, E. D.; White, B. D.; Burnett, V. W.; Maple, M. B.; Lynn, J. W.; et al

    2015-02-01

    We have used specific heat and neutron diffraction measurements on single crystals of URu2–xFexSi? for Fe concentrations x ? 0.7 to establish that chemical substitution of Ru with Fe acts as “chemical pressure” Pch as previously proposed by Kanchanavatee et al. [Phys. Rev. B 84, 245122 (2011)] based on bulk measurements on polycrystalline samples. Notably, neutron diffraction reveals a sharp increase of the uranium magnetic moment at x = 0.1, reminiscent of the behavior at the “hidden order” to large moment antiferromagnetic (LMAFM) phase transition observed at a pressure Px ? 0.5-0.7 GPa in URu?Si?. Using the unit cell volumemore »determined from our measurements and an isothermal compressibility ?T = 5.2×10?³ GPa?¹ for URu?Si?, we determine the chemical pressure Pch in URu2?xFexSi? as a function of x. The resulting temperature T-chemical pressure Pch phase diagram for URu2?xFexSi? is in agreement with the established temperature T-external pressure P phase diagram of URu?Si?.« less

  3. Chemical pressure tuning of URu2Si2 via isoelectronic substitution of Ru with Fe

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

    Das, Pinaki; Kanchanavatee, N.; Helton, J. S.; Huang, K.; Baumbach, R. E.; Bauer, E. D.; White, B. D.; Burnett, V. W.; Maple, M. B.; Lynn, J. W.; et al

    2015-02-26

    We have used specific heat and neutron diffraction measurements on single crystals of URu2–xFexSi? for Fe concentrations x ? 0.7 to establish that chemical substitution of Ru with Fe acts as “chemical pressure” Pch as previously proposed by Kanchanavatee et al. [Phys. Rev. B 84, 245122 (2011)] based on bulk measurements on polycrystalline samples. Neutron diffraction reveals a sharp increase of the uranium magnetic moment at x = 0.1, reminiscent of the behavior at the “hidden order” to large moment antiferromagnetic (LMAFM) phase transition observed at a pressure Px ? 0.5-0.7 GPa in URu?Si?. Using the unit cell volume determinedmore »from our measurements and an isothermal compressibility ?T = 5.2×10?³ GPa?¹ for URu?Si?, we determine the chemical pressure Pch in URu2?xFexSi? as a function of x. The resulting temperature T-chemical pressure Pch phase diagram for URu2?xFexSi? is in agreement with the established temperature T-external pressure P phase diagram of URu?Si?.« less

  4. Tailoring the composition of ultrathin, ternary alloy PtRuFe nanowires for the methanol oxidation reaction and formic acid oxidation reaction

    SciTech Connect (OSTI)

    Scofield, Megan E.; Koenigsmann, Christopher; Wang, Lei; Lui, Haiqing; Wong, Stanislaus S.

    2014-11-25

    In the search for alternatives to conventional Pt electrocatalysts, we have synthesized ultrathin, ternary PtRuFe nanowires (NW), possessing different chemical compositions in order to probe their CO tolerance as well as electrochemical activity as a function of composition for both (i) the methanol oxidation reaction (MOR) and (ii) the formic acid oxidation reaction (FAOR). As-prepared ‘multifunctional’ ternary NW catalysts exhibited both higher MOR and FAOR activity as compared with binary Pt?Ru? NW, monometallic Pt NW, and commercial catalyst control samples. In terms of synthetic novelty, we utilized a sustainably mild, ambient wet-synthesis method never previously applied to the fabrication of crystalline, pure ternary systems in order to fabricate ultrathin, homogeneous alloy PtRuFe NWs with a range of controlled compositions. These NWs were subsequently characterized using a suite of techniques including XRD, TEM, SAED, and EDAX in order to verify not only the incorporation of Ru and Fe into the Pt lattice but also their chemical homogeneity, morphology, as well as physical structure and integrity. Lastly, these NWs were electrochemically tested in order to deduce the appropriateness of conventional explanations such as (i) the bi-functional mechanism as well as (ii) the ligand effect to account for our MOR and FAOR reaction data. Specifically, methanol oxidation appears to be predominantly influenced by the Ru content, whereas formic acid oxidation is primarily impacted by the corresponding Fe content within the ternary metal alloy catalyst itself.

  5. Tailoring the composition of ultrathin, ternary alloy PtRuFe nanowires for the methanol oxidation reaction and formic acid oxidation reaction

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

    Scofield, Megan E. [State Univ. of New York at Stony Brook, Stony Brook, NY (United States); Koenigsmann, Christopher [State Univ. of New York at Stony Brook, Stony Brook, NY (United States); Wang, Lei [State Univ. of New York at Stony Brook, Stony Brook, NY (United States); Lui, Haiqing [State Univ. of New York at Stony Brook, Stony Brook, NY (United States); Wong, Stanislaus S. [State Univ. of New York at Stony Brook, Stony Brook, NY (United States); Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-01-01

    In the search for alternatives to conventional Pt electrocatalysts, we have synthesized ultrathin, ternary PtRuFe nanowires (NW), possessing different chemical compositions in order to probe their CO tolerance as well as electrochemical activity as a function of composition for both (i) the methanol oxidation reaction (MOR) and (ii) the formic acid oxidation reaction (FAOR). As-prepared ‘multifunctional’ ternary NW catalysts exhibited both higher MOR and FAOR activity as compared with binary Pt?Ru? NW, monometallic Pt NW, and commercial catalyst control samples. In terms of synthetic novelty, we utilized a sustainably mild, ambient wet-synthesis method never previously applied to the fabrication of crystalline, pure ternary systems in order to fabricate ultrathin, homogeneous alloy PtRuFe NWs with a range of controlled compositions. These NWs were subsequently characterized using a suite of techniques including XRD, TEM, SAED, and EDAX in order to verify not only the incorporation of Ru and Fe into the Pt lattice but also their chemical homogeneity, morphology, as well as physical structure and integrity. Lastly, these NWs were electrochemically tested in order to deduce the appropriateness of conventional explanations such as (i) the bi-functional mechanism as well as (ii) the ligand effect to account for our MOR and FAOR reaction data. Specifically, methanol oxidation appears to be predominantly influenced by the Ru content, whereas formic acid oxidation is primarily impacted by the corresponding Fe content within the ternary metal alloy catalyst itself.

  6. Tailoring the composition of ultrathin, ternary alloy PtRuFe nanowires for the methanol oxidation reaction and formic acid oxidation reaction

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

    Scofield, Megan E.; Koenigsmann, Christopher; Wang, Lei; Liu, Haiqing; Wong, Stanislaus S.

    2014-11-25

    In the search for alternatives to conventional Pt electrocatalysts, we have synthesized ultrathin, ternary PtRuFe nanowires (NW), possessing different chemical compositions in order to probe their CO tolerance as well as electrochemical activity as a function of composition for both (i) the methanol oxidation reaction (MOR) and (ii) the formic acid oxidation reaction (FAOR). As-prepared ‘multifunctional’ ternary NW catalysts exhibited both higher MOR and FAOR activity as compared with binary Pt?Ru? NW, monometallic Pt NW, and commercial catalyst control samples. In terms of synthetic novelty, we utilized a sustainably mild, ambient wet-synthesis method never previously applied to the fabrication ofmore »crystalline, pure ternary systems in order to fabricate ultrathin, homogeneous alloy PtRuFe NWs with a range of controlled compositions. Thus, these NWs were subsequently characterized using a suite of techniques including XRD, TEM, SAED, and EDAX in order to verify not only the incorporation of Ru and Fe into the Pt lattice but also their chemical homogeneity, morphology, as well as physical structure and integrity. Lastly, these NWs were electrochemically tested in order to deduce the appropriateness of conventional explanations such as (i) the bi-functional mechanism as well as (ii) the ligand effect to account for our MOR and FAOR reaction data. Specifically, methanol oxidation appears to be predominantly influenced by the Ru content, whereas formic acid oxidation is primarily impacted by the corresponding Fe content within the ternary metal alloy catalyst itself.« less

  7. Tailoring the composition of ultrathin, ternary alloy PtRuFe nanowires for the methanol oxidation reaction and formic acid oxidation reaction

    SciTech Connect (OSTI)

    Scofield, Megan E.; Koenigsmann, Christopher; Wang, Lei; Liu, Haiqing; Wong, Stanislaus S.

    2014-11-25

    In the search for alternatives to conventional Pt electrocatalysts, we have synthesized ultrathin, ternary PtRuFe nanowires (NW), possessing different chemical compositions in order to probe their CO tolerance as well as electrochemical activity as a function of composition for both (i) the methanol oxidation reaction (MOR) and (ii) the formic acid oxidation reaction (FAOR). As-prepared ‘multifunctional’ ternary NW catalysts exhibited both higher MOR and FAOR activity as compared with binary Pt?Ru? NW, monometallic Pt NW, and commercial catalyst control samples. In terms of synthetic novelty, we utilized a sustainably mild, ambient wet-synthesis method never previously applied to the fabrication of crystalline, pure ternary systems in order to fabricate ultrathin, homogeneous alloy PtRuFe NWs with a range of controlled compositions. Thus, these NWs were subsequently characterized using a suite of techniques including XRD, TEM, SAED, and EDAX in order to verify not only the incorporation of Ru and Fe into the Pt lattice but also their chemical homogeneity, morphology, as well as physical structure and integrity. Lastly, these NWs were electrochemically tested in order to deduce the appropriateness of conventional explanations such as (i) the bi-functional mechanism as well as (ii) the ligand effect to account for our MOR and FAOR reaction data. Specifically, methanol oxidation appears to be predominantly influenced by the Ru content, whereas formic acid oxidation is primarily impacted by the corresponding Fe content within the ternary metal alloy catalyst itself.

  8. Inverse magnetocaloric effect in Ce(Fe{sub 0.96}Ru{sub 0.04}){sub 2}: Effect of fast neutron irradiation

    SciTech Connect (OSTI)

    Dube, V.; Mishra, P. K.; Prajapat, C. L.; Singh, M. R.; Ravikumar, G.; Rajarajan, A. K.; Sastry, P. U.; Thakare, S. V.

    2013-02-05

    We have shown the effect of fast neutron irradiation on the magnetic phase transition and magnetocaloric effect (MCE) in a doped Ce(Fe{sub 0.96}Ru{sub 0.04}){sub 2}, intermettalic. We show that this leads to suppression of MCE and a to a disordered ferromagnetic phase.

  9. Noncollinear ferromagnetic easy axes in Py/Ru/FeCo/IrMn spin valves induced by oblique deposition

    SciTech Connect (OSTI)

    Bueno, T. E. P.; Parreiras, D. E.; Gomes, G. F. M.; Krambrock, K.; Paniago, R. [Departamento de Física, ICEx, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, MG (Brazil); Michea, S.; Rodríguez-Suárez, R. L. [Centro de Investigación en Nanotecnología y Materiales Avanzados “CIEN-UC,” Pontifícia Universidad Católica de Chile, Casilla 306, Santiago (Chile); Filho, M. S. Araújo; Macedo, W. A. A. [Laboratório de Física Aplicada, Centro de Desenvolvimento da Tecnologia Nuclear, 30123-970 Belo Horizonte, MG (Brazil)

    2014-06-16

    We present an investigation on the magnetic properties of Py/Ru/FeCo/IrMn spin valves grown by dc magnetron sputtering. The sample fabrication setup has two important features, (i) the five magnetron sputtering sources are placed in a cluster flange 72° from each other, and (ii) each source is tilted with respect to the sample normal. In-plane angular dependence of the ferromagnetic resonance (FMR) was used to obtain the relevant magnetic anisotropies, such as uniaxial and exchange bias fields. The oblique deposition geometry employed has induced non-collinear easy axes of the two ferromagnetic (FM) layers, with high uniaxial field strengths. The symmetry shift of the angular dependence of the FMR resonances of the two FM layers gives us directly the angle between the easy axes of FM{sub 1} (Py) and FM{sub 2} (FeCo), which turned out to be the angle between two adjacent sputtering sources. The observations of the present study suggest that, by combining oblique deposition and appropriate angles of incidence of the deposition flux, the uniaxial (and unidirectional) axes of individual FM layers can be precisely engineered in spin valve fabrication.

  10. Percolation theory and quantum critical systems: A new description of the critical behavior in Ce(Ru{sub 0.24}Fe{sub 0.76}){sub 2}Ge{sub 2}

    SciTech Connect (OSTI)

    Gaddy, John [Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211 (United States); Heitmann, Tom, E-mail: HeitmannT@missouri.edu [Missouri Research Reactor, University of Missouri, Columbia, Missouri 65211 (United States); Montfrooij, Wouter [Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211 (United States); Missouri Research Reactor, University of Missouri, Columbia, Missouri 65211 (United States)

    2014-05-07

    The onset of ordering in quantum critical systems is characterized by a competition between the Kondo shielding of magnetic moments and the ordering of these moments. We show how a distribution of Kondo shielding temperatures—resulting from chemical doping—leads to critical behavior whose main characteristics are given by percolation physics. With the aid of Monte Carlo computer simulations, we are able to infer the low temperature part of the distribution of shielding temperatures in heavily doped quantum critical Ce(Ru{sub 0.24}Fe{sub 0.76}){sub 2}Ge{sub 2}. Based on this distribution, we show that the ordering dynamics—such as the growth of the correlation length upon cooling—can be understood by the spawning of magnetic clusters. Our findings explain why the search for universal exponents in quantum critical systems has been unsuccessful: the underlying percolation network associated with the chemical doping of quantum critical systems has to be incorporated in the modeling of these quantum critical systems.

  11. The series of carbon-chain complexes {Ru(dppe)Cp*}?{?-(C?C)x} (x = 4–8, 11): Synthesis, structures, properties and some reactions

    SciTech Connect (OSTI)

    Bruce, Michael I.; Cole, Marcus L.; Ellis, Benjamin G.; Gaudio, Maryka; Nicholson, Brian K.; Parker, Christian R.; Skelton, Brian W.; White, Allan H.

    2015-01-28

    The construction of a series of compounds {Ru(dppe)Cp*}2(?-C2x) (Ru*-C2x-Ru*, x = 4–8, 11)) is described. A direct reaction between RuCl(dppe)Cp* and Me3Si(Ctriple bond; length of mdashC)4SiMe3 afforded Ru*-C8-Ru* in 89% yield. The Pd(0)/Cu(I)-catalysed coupling of Ru{Ctriple bond; length of mdashCCtriple bond; length of mdashCAu(PPh3)}(dppe)Cp*Ru*-C4-Au (2 equiv.) with diiodoethyne gave Ru*-C10-Ru* (64%), or of 1 equiv. with I(Ctriple bond; length of mdashC)3I gave Ru*-C14-Ru* (36%); similarly, Ru{(Ctriple bond; length of mdashC)4Au(PPh3)}(dppe)Cp*Ru*-C8-Au and I(Ctriple bond; length of mdashC)3I gave Ru*-C22-Ru* (12%). Desilylation (TBAF) of Ru{(Ctriple bond; length of mdashC)xSiMe3}(dppe)Cp*Ru*-C2x-Si (x = 3, 4) followed by oxidative coupling [Cu(OAc)2/py] gave Ru*-C12-Ru* (82%) and Ru*-C16-Ru* (58%), respectively. Similar oxidative coupling of Ru(Ctriple bond; length of mdashCCtriple bond; length of mdashCH)(dppe)Cp* was a second route to Ru*-C8-Ru* (82%). Appropriate precursors are already known, or obtained by coupling of Ru*-C2x-Si (x = 2, 4) with AuCl(PPh3)/NaOMe [Ru*-C4-Au, 95%; Ru*-C8-Au, 74%] or from Pd(0)/Cu(I) catalysed coupling of Ru*-C2x-Au (x = 2, 3) with I(Ctriple bond; length of mdashC)2SiMe3 (Ru*-C8-Si, 64%; Ru*-C10-Si, 2%). Reactions between Ru*-C2x-Ru* (x = 3, 4) and Fe2(CO)9 gave {Fe3(CO)9}{?3-CCtriple bond; length of mdashC[Ru(dppe)Cp*]}2Fe(C3-Ru*)2 and {Fe3(CO)9}{?3-CCtriple bond; length of mdashC[Ru(dppe)Cp*]}{?3-C(Ctriple bond; length of mdashC)2[Ru(dppe)Cp*]} Fe(C3-Ru*)(C5-Ru*), respectively. The redox properties of the series of complexes with 2x = 2–16 were measured and showed a diminution of the separation of the first two oxidation potentials, ?E = E2 - E1, with increasing carbon chain length. The X-ray-determined molecular structures of Ru*-C8-Si, Ru*-C8-Ru*, Ru*-C14-Ru* (two C6H6 solvates), {Ru(PPh3)2Cp}2{?-(Ctriple bond; length of mdashC)4}·4CHCl3Ru-C8-Ru·4CHCl3 and of Fe(C3-Ru*)2 and Fe(C3-Ru*)(C5-Ru*) are reported.

  12. B.H. Far's Research far@ucalgary.ca

    E-Print Network [OSTI]

    Far, Behrouz Homayoun

    B.H. Far's Research © B.H. Far far@ucalgary.ca http://www.enel.ucalgary.ca/People/far 1 Theme 6 of knowledge representation and consequently allows machines to exchange knowledge and process it infrastructure evaded organizations until the advent of the Internet. Open Internet standards present

  13. Microsoft Word - InterfacialElectron bh

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

    Band structure of 1 UC FeSe film on STO. a, The Fermi surface, consisting of only pockets near the M-point. b-c, The measured dispersion along the high symmetry cut near the zone...

  14. Investigation of the synthesis, activation, and isosteric heats of CO? adsorption of the isostructural series of metal-organic frameworks M?(BTC)? (M = Cr, Fe, Ni, Cu, Mo, Ru)

    E-Print Network [OSTI]

    Wade, Casey

    The synthesis, activation, and heats of CO? adsorption for the known members of the M?(BTC)? (HKUST-1) isostructural series (M = Cr, Fe, Ni, Zn, Ni, Cu, Mo) were investigated to gain insight into the impact of CO?–metal ...

  15. Simulating Ru L3-Edge X-ray Absorption Spectroscopy with Time-Dependent Density Functional Theory: Model Complexes and Electron Localization in Mixed-Valence Metal Dimers

    SciTech Connect (OSTI)

    Kuiken, Benjamin E. Van; Valiev, Marat; Daifuku, Stephanie L.; Bannan, Caitlin; Strader, Matthew L.; Cho, Hana; Huse, Nils; Schoenlein, Robert W.; Govind, Niranjan; Khalil, Munira

    2013-04-26

    Ruthenium L3-edge X-ray absorption (XA) spectroscopy probes unoccupied 4d orbitals of the metal atom and is increasingly being used to investigate the local electronic structure in ground and excited electronic states of Ru complexes. The simultaneous development of computational tools for simulating Ru L3-edge spectra is crucial for interpreting the spectral features at a molecular level. This study demonstrates that time-dependent density functional theory (TDDFT) is a viable and predictive tool for simulating ruthenium L3-edge XA spectroscopy. We systematically investigate the effects of exchange correlation functional and implicit and explicit solvent interactions on a series of RuII and RuIII complexes in their ground and electronic excited states. The TDDFT simulations reproduce all of the experimentally observed features in Ru L3-edge XA spectra within the experimental resolution (0.4 eV). Our simulations identify ligand-specific charge transfer features in complicated Ru L3-edge spectra of [Ru(CN)6]4- and RuII polypyridyl complexes illustrating the advantage of using TDDFT in complex systems. We conclude that the B3LYP functional most accurately predicts the transition energies of charge transfer features in these systems. We use our TDDFT approach to simulate experimental Ru L3-edge XA spectra of transition metal mixed-valence dimers of the form [(NC)5MII-CN-RuIII(NH3)5] (where M = Fe or Ru) dissolved in water. Our study determines the spectral signatures of electron delocalization in Ru L3-edge XA spectra. We find that the inclusion of explicit solvent molecules is necessary for reproducing the spectral features and the experimentally determined valencies in these mixed-valence complexes. This study validates the use of TDDFT for simulating Ru 2p excitations using popular quantum chemistry codes and providing a powerful interpretive tool for equilibrium and ultrafast Ru L3-edge XA spectroscopy.

  16. Glycerol Hydrogenolysis on Carbon-Supported PtRu and AuRu Bimetallic Catalysts

    SciTech Connect (OSTI)

    Maris,E.; Ketchie, W.; Murayama, M.; Davis, R.

    2007-01-01

    Bimetallic PtRu and AuRu catalysts were prepared by a surface redox method in which Pt or Au was deposited onto the surface of carbon-supported Ru nanoparticles with an average diameter of 2-3 nm. Characterization by H2 chemisorption, analytical TEM, and X-ray absorption spectroscopy at the Ru K-edge, Pt LIII-edge, and Au LIII-edge confirmed that Pt and Au were successfully deposited onto Ru without disrupting the Ru particles. Depression of the ethane hydrogenolysis rate over Ru after addition of Au provided further evidence of successful deposition. The bimetallic particles were subsequently evaluated in the aqueous-phase hydrogenolysis of glycerol at 473 K and 40 bar H2 at neutral and elevated pH. Although monometallic Pt and Ru exhibited different activities and selectivities to products, the bimetallic PtRu catalyst functioned more like Ru. A similar result was obtained for the AuRu bimetallic catalyst. The PtRu catalyst appeared to be stable under the aqueous-phase reaction conditions, whereas the AuRu catalyst was altered by the harsh conditions. Gold appeared to migrate off the Ru and agglomerate on the carbon during the reaction in liquid water.

  17. Black Hole Demographics from the M(BH)-sigma Relation

    E-Print Network [OSTI]

    David Merritt; Laura Ferrarese

    2001-03-03

    We analyze a sample of 32 galaxies for which a dynamical estimate of the mass of the hot stellar component, M_bulge, is available. For each of these galaxies, we calculate the mass of the central black hole, M_BH, using the tight empirical correlation between M_BH and the bulge stellar velocity dispersion. The frequency function N(log M_BH/M_bulge) is reasonably well described as a Gaussian with ~ -2.90 and standard deviation 0.45; the implied mean ratio of black hole to bulge mass is a factor 5 smaller than generally quoted in the literature. We present marginal evidence for a lower, average black-hole mass fraction in more massive galaxies. The total mass density in black holes in the local Universe is estimated to be 5 x 10^5 solar masses per cubic megaparsec, consistent with that inferred from high redshift (z ~ 2) AGNs.

  18. The M(BH)-Sigma Relation for Supermassive Black Holes

    E-Print Network [OSTI]

    David Merritt; Laura Ferrarese

    2000-08-20

    We investigate the differences in the M(BH)-sigma relation derived recently by Ferrarese & Merritt (2000) and Gebhardt et al. (2000). The shallower slope found by the latter authors (3.75 vs. 4.8) is due partly to the use of a regression algorithm that ignores measurement errors, and partly to the value of the velocity dispersion adopted for a single galaxy, the Milky Way. A steeper relation is shown to provide a better fit to black hole masses derived from reverberation mapping studies. Combining the stellar dynamical, gas dynamical, and reverberation mapping mass estimates, we derive a best-fit relation M(BH) = 1.30 (+/- 0.36) X 10^8 (sigma_c/200)^{4.72(+/- 0.36)}, where M(BH) is in solar masses, and sigma in km/s.

  19. Graphene on Ru(0001) Moire Corrugation Studied by Scanning Tunneling Microscopy on Au/Graphene/Ru(0001) Heterostructures

    E-Print Network [OSTI]

    Ciobanu, Cristian

    Graphene on Ru(0001) Moire Corrugation Studied by Scanning Tunneling Microscopy on Au/Graphene on graphene/Ru(0001) were used to study the corrugation of the moire structure of graphene/Ru(0001 for the graphene/Ru(0001) moire is of structural nature rather than electronic. STM showed a large value

  20. Graphene Growth by Metal Etching on Ru (0001)

    E-Print Network [OSTI]

    Loginova, Elena

    2010-01-01

    of step etching during graphene growth, such as in Fig. 3,adsorption of water on graphene structures will be describedRu(0001) Figure 5. a b c graphene Ru d Figure 6. Figure 7. a

  1. Adsorption of intact methanol on Ru,,0001... Pawel Gazdzicki,1

    E-Print Network [OSTI]

    Adsorption of intact methanol on Ru,,0001... Pawel Gazdzicki,1 Per Uvdal,2 and Peter Jakob1,a 1 the adsorption of methanol on the clean Ru 0001 surface at T 80 K. Thereby, clear evidence for intact adsorption upon adsorption of methanol on Ru 0001 , even at low temperatures, as well as partial recombinative

  2. The structure of energy levels in ¹?²RU 

    E-Print Network [OSTI]

    Bouttchenko, Sviatoslav Olegovich

    1998-01-01

    of Physical Review C. The spectral structure of even-even Ru isotopes, which for a long time were considered vibrational nuclei [1, 2], is a good example of the complexity present in this region. For the Ru isotopes the region of interest covers from shell... of light (Z=1, 2) particles are produced with energies much higher than those from evaporation. In these massive-transfer, or incomplete fusion reactions a light energetic fragment from the projectile is emitted in the field of the target, while...

  3. Modeling and Optimization of Polymer based Bulk Heterojunction (BH) Solar cell * Biswajit Ray, Pradeep R. Nair, R. Edwin Garca1

    E-Print Network [OSTI]

    Alam, Muhammad A.

    of the morphology can double the efficiency of BH cells. 1. Introduction Polymer based organic solar cell remains/devices of organic cells to achievable efficiency. The cartoon of a BH solar cell in Fig. 1a illustrates four keyModeling and Optimization of Polymer based Bulk Heterojunction (BH) Solar cell * Biswajit Ray

  4. AuRu/AC as an effective catalyst for hydrogenation reactions

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

    Villa, Alberto; Chan-Thaw, Carine E.; Campisi, Sebastiano; Bianchi, Claudia L.; Wang, Di; Kotula, Paul G.; Kübel, Christian; Prati, Laura

    2015-03-23

    AuRu bimetallic catalysts have been prepared by sequential deposition of Au on Ru or vice versa obtaining different nanostructures: when Ru has been deposited on Au, a Aucore–Rushell has been observed, whereas the deposition of Au on Ru leads to a bimetallic phase with Ru enrichment on the surface. In the latter case, the unexpected Ru enrichment could be attributed to the weak adhesion of Ru on the carbon support, thus allowing Ru particles to diffuse on Au particles. Both structures result very active in catalysing the liquid phase hydrogenolysis of glycerol and levulinic acid but the activity, the selectivitymore »and the stability depend on the structure of the bimetallic nanoparticles. Ru@Au/AC core–shell structure mostly behaved as the monometallic Ru, whereas the presence of bimetallic AuRu phase in Au@Ru/AC provides a great beneficial effect on both activity and stability.« less

  5. Comparison of complementary reactions for the production of {sup 261,262}Bh

    SciTech Connect (OSTI)

    Nelson, S. L.; Folden III, C. M.; Dragojevic, I.; Garcia, M. A.; Gates, J. M.; Nitsche, H.; Gregorich, K. E.; Sudowe, R.; Duellmann, Ch. E.; Eichler, R.

    2008-08-15

    Two heavy-ion induced fusion reactions producing {sup 261,262}Bh were studied using the Berkeley Gas-filled Separator at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron. An excitation function for the production of {sup 262}Bh via the reaction {sup 209}Bi({sup 54}Cr,n){sup 262}Bh was measured with a maximum cross section from a fit to the data of 430 {+-} 110 pb observed at a compound nucleus excitation energy of 15.7 MeV. New data have been measured for the 1n exit channel of the {sup 208}Pb({sup 55}Mn, n){sup 262}Bh reaction. We present an updated excitation function with an observed maximum cross section of 530{+-}100 pb at a compound nucleus excitation energy of 14.1 MeV. Events corresponding to the 2n exit channel for the {sup 209}Bi({sup 54}Cr,2n){sup 261}Bh and {sup 208}Pb({sup 55}Mn,2n){sup 261}Bh reactions were also observed and are presented as partial excitation functions. The measured decay properties correspond well with existing experimental data. We compare these experimental results to cross section predictions from a model by Swiatecki et al. and discuss entrance channel effects on the magnitude of 1n cross sections.

  6. Approved Module Information for BH2212, 2014/5 Module Title/Name: Theories and practice of HRM Module Code: BH2212

    E-Print Network [OSTI]

    Neirotti, Juan Pablo

    Approved Module Information for BH2212, 2014/5 Module Title/Name: Theories and practice of HRM professional in organisations. Indicative Module Content: The Context of HRM Weeks1-5 In the first five weeks, we will examine and understand the nature of HRM, its historical evolution and its contribution

  7. Low energy electron bombardment induced surface contamination of Ru mirrors

    E-Print Network [OSTI]

    Harilal, S. S.

    Low energy electron bombardment induced surface contamination of Ru mirrors A. Al-Ajlonya , A., Albany, NY 12203, USA ABSTRACT The impact of secondary electrons induced contamination of the Ru surface, carbon contamination, Ruthenium capping 1. INTRODUCTION Extreme ultraviolet (EUV) radiation induced

  8. Enhanced thermoelectric power and electronic correlations in RuSe?

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

    Wang, Kefeng; Wang, Aifeng; Tomic, A.; Wang, Limin; Abeykoon, A. M. Milinda; Dooryhee, E.; Billinge, S. J.L.; Petrovic, C.

    2015-03-03

    We report the electronic structure, electric and thermal transport properties of Ru??xIrxSe? (x ? 0.2). RuSe? is a semiconductor that crystallizes in a cubic pyrite unit cell. The Seebeck coefficient of RuSe? exceeds -200 µV/K around 730 K. Ir substitution results in the suppression of the resistivity and the Seebeck coefficient, suggesting the removal of the peaks in density of states near the Fermi level. Ru?.?Ir?.?Se? shows a semiconductor-metal crossover at about 30 K. The magnetic field restores the semiconducting behavior. Our results indicate the importance of the electronic correlations in enhanced thermoelectricity of RuSb?.

  9. 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.

  10. MoRu/Be multilayers for extreme ultraviolet applications

    DOE Patents [OSTI]

    Bajt, Sasa C. (Livermore, CA); Wall, Mark A. (Stockton, CA)

    2001-01-01

    High reflectance, low intrinsic roughness and low stress multilayer systems for extreme ultraviolet (EUV) lithography comprise amorphous layers MoRu and crystalline Be layers. Reflectance greater than 70% has been demonstrated for MoRu/Be multilayers with 50 bilayer pairs. Optical throughput of MoRu/Be multilayers can be 30-40% higher than that of Mo/Be multilayer coatings. The throughput can be improved using a diffusion barrier to make sharper interfaces. A capping layer on the top surface of the multilayer improves the long-term reflectance and EUV radiation stability of the multilayer by forming a very thin native oxide that is water resistant.

  11. Supporting Information Monodisperse PtRu Nanoalloy on Carbon

    E-Print Network [OSTI]

    Kwak, Juhyoun

    Advanced Institute of Science and Technology, Daejeon, 305-701, Korea. E-mail: joontpark.0%, Junsei) at 80 °C for 10 h. The resulting PtRu/Vc catalyst was collected by centrifugation, washed

  12. Approved Module Information for BH3392, 2014/5 Module Title/Name: Learning, Training and Development in

    E-Print Network [OSTI]

    Neirotti, Juan Pablo

    Approved Module Information for BH3392, 2014/5 Module Title/Name: Learning, Training and Development in Organisations Module Code: BH3392 School: Aston Business School Module Type: Standard Module New Module? No Module Credits: 10 Module Management Information Module Leader Name Alison J. Glaister

  13. Investigation of high temperature gaseous species by Knudsen cell mass spectrometry above the condensed systems Cu-Y-Ru-C, Ag-Y-Ru-C, and Au-Y- Ru-C 

    E-Print Network [OSTI]

    Wilhite, Dale Wayne

    1988-01-01

    using the Third-law method. In addition, the molecules Cu , RuC, and YC were investigated using the Second-law method and the Third-law method. The reactions investigated are listed below: 2 Cu (g) = Cu 2 (g) 2 Ag (g) - Ag2 (g) Ru (g) + C (graphite...) = RuC (g) (g) + 2 C (graphite) YC (g) 2 Y (g) + Au (g) = YAu (g) Y (g) + Au (g) 2 Y (g) + Cu (g) YAu (g) + Au (g) = Ycu (g) Y (g) + Cu (g) YCu (g) + Cu (g) 2 Y (g) + Ru (g) YRu (g) Y (g) + RuC (g) YRu (g) + C (graphite) The reaction enthalpies...

  14. BH-2 Mainframe Chassis 65-0200 IP-2 Iontophoresis Pump Module 65-0203

    E-Print Network [OSTI]

    BH-2 Mainframe Chassis 65-0200 IP-2 Iontophoresis Pump Module 65-0203 PPM-2 Pneumatic Pump Module Module ..............6 MS-2 Power Supply ..........................................6 IP-2 Pump Module ..............................................7-8 PPM-2 Pneumatic Pump Module ..........................9 Recommended Setup Procedure

  15. REVERSIBLE HYDROGEN STORAGE IN A LiBH{sub 4}-C{sub 60} NANOCOMPOSITE

    SciTech Connect (OSTI)

    Teprovich, J.; Zidan, R.; Peters, B.; Wheeler, J.

    2013-08-06

    Reversible hydrogen storage in a LiBH{sub 4}:C{sub 60} nanocomposite (70:30 wt. %) synthesized by solvent-assisted mixing has been demonstrated. During the solvent-assisted mixing and nanocomposite formation, a chemical reaction occurs in which the C{sub 60} cages are significantly modified by polymerization as well as by hydrogenation (fullerane formation) in the presence of LiBH{sub 4}. We have determined that two distinct hydrogen desorption events are observed upon rehydrogenation of the material, which are attributed to the reversible formation of a fullerane (C{sub 60}H{sub x}) as well as a LiBH4 species. This system is unique in that the carbon species (C{sub 60}) actively participates in the hydrogen storage process which differs from the common practice of melt infiltration of high surface area carbon materials with LiBH{sub 4} (nanoconfinment effect). This nanocomposite demonstrated good reversible hydrogen storage properties as well as the ability to absorb hydrogen under mild conditions (pressures as low as 10 bar H{sub 2} or temperatures as low as 150?C). The nanocomposite was characterized by TGA-RGA, DSC, XRD, LDI-TOF-MS, FTIR, 1H NMR, and APPI MS.

  16. 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.

  17. Fabrication of 3D Core-Shell Multiwalled Carbon Nanotube@RuO2...

    Office of Scientific and Technical Information (OSTI)

    Multiwalled Carbon Nanotube@RuO2 Lithium-Ion Battery Electrodes through a RuO2 Atomic Layer Deposition Process Citation Details In-Document Search Title: Fabrication of 3D...

  18. Complex of transferrin with ruthenium for medical applications. [Ru 97, Ru 103

    DOE Patents [OSTI]

    Richards, P.; Srivastava, S.C.; Meinken, G.E.

    1980-11-03

    A novel Ruthenium-transferrin complex, prepared by reacting iron-free human transferrin dissolved in a sodium acetate solution at pH 7 with ruthenium by heating at about 40/sup 0/C for about 2 hours, and purifying said complex by means of gel chromatography with pH 7 sodium acetate as eluent. The mono- or di-metal complex produced can be used in nuclear medicine in the diagnosis and/or treatment of tumors and abscesses. Comparitive results with Ga-67-citrate, which is the most widely used tumor-localizing agent in nuclear medicine, indicate increased sensitivity of detection and greater tumor uptake with the Ru-transferrin complex.

  19. Termination of star formation by BH feedback in equal- and unequal-mass mergers of disk and elliptical galaxies

    E-Print Network [OSTI]

    Peter H. Johansson; Thorsten Naab; Andreas Burkert

    2008-09-19

    We present binary galaxy merger simulations of gas-rich disks (Sp-Sp), of early-type galaxies and disks (E-Sp, mixed mergers), and mergers of early-type galaxies (E-E, dry mergers) with varying mass ratios and different progenitor morphologies. The simulations include radiative cooling, star formation and black hole (BH) accretion and the associated feedback processes. We find for Sp-Sp mergers, that the peak star formation rate and BH accretion rate decrease and the growth timescales of the central black holes and newly formed stars increase with higher progenitor mass ratios. The termination of star formation by BH feedback in disk mergers is significantly less important for higher progenitor mass ratios (e.g. 3:1 and higher). In addition, the inclusion of BH feedback suppresses efficiently star formation in dry E-E mergers and mixed E-Sp mergers.

  20. Development of bulk-type all-solid-state lithium-sulfur battery using LiBH{sub 4} electrolyte

    SciTech Connect (OSTI)

    Unemoto, Atsushi, E-mail: unemoto@imr.tohoku.ac.jp; Ikeshoji, Tamio [WPI-Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Yasaku, Syun; Matsuo, Motoaki [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Nogami, Genki; Tazawa, Masaru; Taniguchi, Mitsugu [Mitsubishi Gas Chemicals Co., Ltd., 182 Tayuhama Shinwari, Kita-ku, Niigata 950-3112 (Japan); Orimo, Shin-ichi [WPI-Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)

    2014-08-25

    Stable battery operation of a bulk-type all-solid-state lithium-sulfur battery was demonstrated by using a LiBH{sub 4} electrolyte. The electrochemical activity of insulating elemental sulfur as the positive electrode was enhanced by the mutual dispersion of elemental sulfur and carbon in the composite powders. Subsequently, a tight interface between the sulfur-carbon composite and the LiBH{sub 4} powders was manifested only by cold-pressing owing to the highly deformable nature of the LiBH{sub 4} electrolyte. The high reducing ability of LiBH{sub 4} allows using the use of a Li negative electrode that enhances the energy density. The results demonstrate the interface modification of insulating sulfur and the architecture of an all-solid-state Li-S battery configuration with high energy density.

  1. Asperity contacts at the nanoscale: Comparison of Ru and Au

    SciTech Connect (OSTI)

    Fortini, Andrea; Buldyrev, Sergey; Srolovitz, David [Department of Physics, Yeshiva University, 500 West 185th Street, New York, New York 10033 (United States); Mendelev, Mikhail I. [Materials and Engineering Physics, Ames Laboratory, Ames, Iowa 50011 (United States)

    2008-10-01

    We develop and validate an interatomic potential for ruthenium based on the embedded atom method framework with the Finnis/Sinclair representation. We confirm that the potential yields a stable hcp lattice with reasonable lattice and elastic constants and surface and stacking fault energies. We employ molecular dynamics simulations to bring two surfaces together, one flat and the other with a single asperity. We compare the process of asperity contact formation and breaking in Au and Ru, two materials currently in use in microelectromechanical system switches. While Au is very ductile at 150 and 300 K, Ru shows considerably less plasticity at 300 and 600 K (approximately the same homologous temperature). In Au, the asperity necks down to a single atom thick bridge at separation. While similar necking occurs in Ru at 600 K, it is much more limited than in Au. On the other hand, at 300 K, Ru breaks by a much more brittle process of fracture/decohesion with limited plastic deformation.

  2. Synthesis of Pd9Ru@Pt nanoparticles for oxygen reduction reaction in acidic electrolytes

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

    Sun, Yu; Hsieh, Yu -Chi; Chang, Li -Chung; Wu, Pu -Wei; Lee, Jyh -Fu

    2014-11-22

    Nanoparticles of PdRu, Pd?Ru, and Pd?Ru are synthesized and impregnated on carbon black via a wet chemical reflux process. X-ray diffraction patterns of the as-synthesized samples, PdxRu/C (x=1/3/9), suggest succesful formation of alloy without presence of individual Pd and Ru nanoparticles. Images from transmission electron microscope confirm irregularly-shaped nanoparticles with average size below 3 nm. Analysis from extended X-ray absorption fine structure on both Pd and Ru K-edge absorption profiles indicate the Ru atoms are enriched on the surface of PdxRu/C. Among these samples, the Pd?Ru/C exhibits the strongest electrocatalytic activity for oxygen reduction reaction (ORR) in an oxygen-saturated 0.1more »M aqueous HClO? solution. Subsequently, the Pd?Ru/C undegoes Cu under potential deposition, followed by a galvanic displacement reaction to deposit a Pt monolayer on the Pd?Ru surface (Pd?Ru@Pt). The Pd?Ru@Pt reveals better ORR performance than that of Pt, reaching a mass activity of 0.38 mA ?g?¹ Pt, as compared to that of commercially available Pt nanoparticles (0.107 mA ?g?¹ Pt). Thus, the mechanisms responsible for the ORR enhancement are attributed to the combined effects of lattice strain and ligand interaction. In addition, this core-shell Pd?Ru@Pt electrocatalyst represents a substantial reduction in the amount of Pt consumption and raw material cost.« less

  3. Synthesis of Pd?Ru@Pt nanoparticles for oxygen reduction reaction in acidic electrolytes

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

    Sun, Yu; Hsieh, Yu-Chi; Chang, Li-Chung; Wu, Pu-Wei; Lee, Jyh-Fu

    2014-11-22

    Nanoparticles of PdRu, Pd?Ru, and Pd?Ru are synthesized and impregnated on carbon black via a wet chemical reflux process. X-ray diffraction patterns of the as-synthesized samples, PdxRu/C (x=1/3/9), suggest succesful formation of alloy without presence of individual Pd and Ru nanoparticles. Images from transmission electron microscope confirm irregularly-shaped nanoparticles with average size below 3 nm. Analysis from extended X-ray absorption fine structure on both Pd and Ru K-edge absorption profiles indicate the Ru atoms are enriched on the surface of PdxRu/C. Among these samples, the Pd?Ru/C exhibits the strongest electrocatalytic activity for oxygen reduction reaction (ORR) in an oxygen-saturated 0.1more »M aqueous HClO? solution. Subsequently, the Pd?Ru/C undegoes Cu under potential deposition, followed by a galvanic displacement reaction to deposit a Pt monolayer on the Pd?Ru surface (Pd?Ru@Pt). The Pd?Ru@Pt reveals better ORR performance than that of Pt, reaching a mass activity of 0.38 mA ?g?¹ Pt, as compared to that of commercially available Pt nanoparticles (0.107 mA ?g?¹ Pt). The mechanisms responsible for the ORR enhancement are attributed to the combined effects of lattice strain and ligand interaction. In addition, this core-shell Pd?Ru@Pt electrocatalyst represents a substantial reduction in the amount of Pt consumption and raw material cost.« less

  4. Synthesis of Pd?Ru@Pt nanoparticles for oxygen reduction reaction in acidic electrolytes

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

    Sun, Yu [National Chiao Tung Univ., Hsin-chu (Taiwan); Hsieh, Yu-Chi [Brookhaven National Lab. (BNL), Upton, NY (United States); Chang, Li-Chung [National Chiao Tung Univ., Hsin-chu (Taiwan); Wu, Pu-Wei [National Chiao Tung Univ., Hsin-chu (Taiwan); Lee, Jyh-Fu [National Synchrotron Radiation Research Center, Hsin-chu (Taiwan)

    2015-03-01

    Nanoparticles of PdRu, Pd?Ru, and Pd?Ru are synthesized and impregnated on carbon black via a wet chemical reflux process. X-ray diffraction patterns of the as-synthesized samples, PdxRu/C (x=1/3/9), suggest succesful formation of alloy without presence of individual Pd and Ru nanoparticles. Images from transmission electron microscope confirm irregularly-shaped nanoparticles with average size below 3 nm. Analysis from extended X-ray absorption fine structure on both Pd and Ru K-edge absorption profiles indicate the Ru atoms are enriched on the surface of PdxRu/C. Among these samples, the Pd?Ru/C exhibits the strongest electrocatalytic activity for oxygen reduction reaction (ORR) in an oxygen-saturated 0.1 M aqueous HClO? solution. Subsequently, the Pd?Ru/C undegoes Cu under potential deposition, followed by a galvanic displacement reaction to deposit a Pt monolayer on the Pd?Ru surface (Pd?Ru@Pt). The Pd?Ru@Pt reveals better ORR performance than that of Pt, reaching a mass activity of 0.38 mA ?g?¹ Pt, as compared to that of commercially available Pt nanoparticles (0.107 mA ?g?¹ Pt). The mechanisms responsible for the ORR enhancement are attributed to the combined effects of lattice strain and ligand interaction. In addition, this core-shell Pd?Ru@Pt electrocatalyst represents a substantial reduction in the amount of Pt consumption and raw material cost.

  5. Photoelectrocatalytic study of water oxidation at n-RuS{sub 2} electrodes

    SciTech Connect (OSTI)

    Salvador, P.; Alonso-Vante, N.; Tributsch, H.

    1998-01-01

    A kinetic study of the photocatalytic oxidation of water at a n-RuS{sub 2} semiconducting single crystal has been undertaken on the basis of photocurrent transients (photocurrent-time behavior as a function of the polarization potential, illumination intensity, and temperature) and electrolyte electroreflectance experiments. The main factor defining the catalytic activity of RuS{sub 2} for water oxidation, both in the dark and under illumination, is a low overpotential ({eta} {approx} 0.3 V), which is comparable to that of the RuO{sub 2} catalyst for oxygen evolution at darkness. Evidence has been given that {eta} is determined by the E{sup o}(Ru{sub s}-OH{sup 0}/Ru{sub s}-H{sub 2}O) redox potential, which strongly depends on the bonding energy of Ru surface species with OH{sup o} radicals generated by direct oxidation of adsorbed water molecules (interfacial Ru-peroxo-type complex formation). This bonding energy increases as the RuS{sub 2} surface becomes oxidized under anodic polarization and reaches its maximum value at the potential of the S{sub 2}RuO{sub 2}/RuS{sub 2} transition (VIII Ru oxidation state). Further oxidation of the Ru-peroxo-type complexes leads to oxygen evolution at a rate which increases with the degree of oxidation of the Ru surface active centers. Although O{sub 2} evolution probably already takes place on Ru(VI) surface sites, high evolution rates (current densities) are only reached under oxidation state VIII. However, in this state (idealized S{sub 2}Ru(VIII)O{sub 2}) Ru-S surface bonds are weakened and occasionally broken, contributing to RuS{sub 2} dissolution with generation of volatile RuO{sub 4} and SO{sub 4}{sup 2{minus}} soluble ions as the main corrosion products. This phenomenon may be attributed to the reaction in acidic medium of H{sub 2}O molecules with Ru(VIII) surface species, giving rise to the formation of unstable intermediate complexes.

  6. Generators of KMS Symmetric Markov Semigroups on B(h) Symmetry and Quantum Detailed Balance

    E-Print Network [OSTI]

    F. Fagnola; V. Umanitá

    2009-08-06

    We find the structure of generators of norm continuous quantum Markov semigroups on B(h) that are symmetric with respect to the scalar product tr(\\rho^{1/2}x\\rho^{1/2}y) induced by a faithful normal invariant state invariant state \\rho and satisfy two quantum generalisations of the classical detailed balance condition related with this non-commutative notion of symmetry: the so-called standard detailed balance condition and the standard detailed balance condition with an antiunitary time reversal.

  7. COSMIC EVOLUTION OF BLACK HOLES AND SPHEROIDS. IV. THE M{sub BH}-L{sub sph} RELATION

    SciTech Connect (OSTI)

    Bennert, Vardha Nicola; Treu, Tommaso; Le Bris, Alexandre; Auger, Matthew W. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Woo, Jong-Hak; Malkan, Matthew A. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Gallagher, Sarah [Department of Physics and Astronomy, University of Western Ontario, 1151 Richmond Street, London, ON N6A 3K7 (Canada); Blandford, Roger D., E-mail: bennert@physics.ucsb.ed, E-mail: tt@physics.ucsb.ed, E-mail: mauger@physics.ucsb.ed, E-mail: woo@astro.ucla.ed, E-mail: malkan@astro.ucla.ed, E-mail: alexandrelebris@gmail.co, E-mail: sgalla4@uwo.c, E-mail: rdb@slac.stanford.ed [Kavli Institute for Particle Astrophysics and Cosmology, Stanford, CA 94305 (United States)

    2010-01-10

    From high-resolution images of 23 Seyfert-1 galaxies at z = 0.36 and z = 0.57 obtained with the Near-Infrared Camera and Multi-Object Spectrometer on board the Hubble Space Telescope (HST), we determine host-galaxy morphology, nuclear luminosity, total host-galaxy luminosity, and spheroid luminosity. Keck spectroscopy is used to estimate black hole mass (M{sub BH}). We study the cosmic evolution of the M{sub BH}-spheroid luminosity (L{sub sph}) relation. In combination with our previous work, totaling 40 Seyfert-1 galaxies, the covered range in BH mass is substantially increased, allowing us to determine for the first time intrinsic scatter and correct evolutionary trends for selection effects. We re-analyze archival HST images of 19 local reverberation-mapped active galaxies to match the procedure adopted at intermediate redshift. Correcting spheroid luminosity for passive luminosity evolution and taking into account selection effects, we determine that at fixed present-day V-band spheroid luminosity, M{sub BH}/L{sub sph} propor to(1 + z){sup 2.8+}-{sup 1.2}. When including a sample of 44 quasars out to z = 4.5 taken from the literature, with luminosity and BH mass corrected to a self-consistent calibration, we extend the BH mass range to over 2 orders of magnitude, resulting in M{sub BH}/L{sub sph} propor to(1 + z){sup 1.4+}-{sup 0.2}. The intrinsic scatter of the relation, assumed constant with redshift, is 0.3 +- 0.1 dex (<0.6 dex at 95% CL). The evolutionary trend suggests that BH growth precedes spheroid assembly. Interestingly, the M{sub BH}-total-host-galaxy-luminosity relation is apparently non-evolving. It hints at either a more fundamental relation or that the spheroid grows by a redistribution of stars. However, the high-z sample does not follow this relation, indicating that major mergers may play the dominant role in growing spheroids above z approx = 1.

  8. Dimerization Induced Deprotonation of Water on RuO2(110)

    SciTech Connect (OSTI)

    Mu, Rentao; Cantu Cantu, David; Lin, Xiao; Glezakou, Vassiliki Alexandra; Wang, Zhitao; Lyubinetsky, Igor; Rousseau, Roger J.; Dohnalek, Zdenek

    2014-10-02

    RuO2 has proven to be indispensable as a co-catalyst in numerous systems designed for photocatalytic water splitting. In this study we have carried out a detailed mechanistic study of water behavior on the most stable RuO2 face, RuO2(110), by employing variable temperature scanning tunneling microscopy and density functional theory calculations. We show that water monomers adsorb molecularly on Ru sites, become mobile above 238 K, diffuse along the Ru rows and form water dimers. The onset for dimer diffusion is observed at ~277 K indicating significantly higher diffusion barrier than that for monomers. More importantly, we find that water dimers deprotonate readily to form Ru-bound H3O2 and bridging OH species. The observed behavior is compared and contrasted with that observed for water on isostructural rutile TiO2(110).

  9. Synthesis and characterization of phosphine adducts of thorium borohydride, Crystal structures of Th(BH4)4(PEt3)2 and Th(BH4)4(Me2PCH2CH2PMe2)2

    E-Print Network [OSTI]

    Girolami, Gregory S.

    Synthesis and characterization of phosphine adducts of thorium borohydride, Th(BH4)4 Crystal: Thorium Phosphine Trialkylphosphine Borohydride Tetrahydroborate Crystal structures a b s t r a c NMR spectroscopy. The results show that thorium complexes of unidentate phosphines can be made

  10. 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...

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

    SciTech Connect (OSTI)

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

    2012-11-15

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

  12. Journal of Power Sources 165 (2007) 509516 Direct NaBH4/H2O2 fuel cells

    E-Print Network [OSTI]

    Carroll, David L.

    2007-01-01

    Journal of Power Sources 165 (2007) 509­516 Direct NaBH4/H2O2 fuel cells George H. Mileya,e,, Nie online 5 December 2006 Abstract A fuel cell (FC) using liquid fuel and oxidizer is under investigation. H Published by Elsevier B.V. Keywords: Fuel cell; Hydrogen peroxide; Regenerative fuel cell; Sodium

  13. Module Information for BH3392, 2015/6 -APPROVED Module Title/Name: Learning, Training and Development in

    E-Print Network [OSTI]

    Rebollo-Neira, Laura

    Module Information for BH3392, 2015/6 - APPROVED Module Title/Name: Learning, Training components of training design and critically examine their core underlying theories. Indicative Module: The module takes into account the role of learning, training and development in organisation

  14. Enhanced Magnetism in Epitaxial SrRuO3 Thin Films

    SciTech Connect (OSTI)

    Grutter, A.J.; Wong, F.; Arenholz, E.; Liberati, M.; Vailionis, A.; Suzuki, Y.

    2009-11-20

    We have observed enhanced magnetization in epitaxial SrRuO{sub 3} thin films compared to previously reported bulk and thin film values of 1.1-1.6 {mu}{sub B}/Ru ion. The degree of enhancement is strongly dependent on the lattice distortions imposed on the SrRuO{sub 3} films by SrTiO{sub 3}, (LaAlO{sub 3}){sub 0.3}(SrTaO{sub 3}){sub 0.7} (LSAT), and LaAlO{sub 3} substrates. A larger enhancement of magnetization for coherently strained SrRuO{sub 3} films on SrTiO{sub 3} and LSAT compared to fully relaxed films on LaAlO{sub 3} confirms the importance of the strain state in determining the magnetic ground state of the Ru ion. In particular, SrRuO{sub 3} films on (111) SrTiO{sub 3} exhibit exhanced moments as high as 3.8 {mu}{sub B}/Ru ion, thus suggesting the stabilization of a high-spin Ru{sup 4+} state.

  15. Mechanism of water oxidation by [Ru(bda)(L)?]: The return of the "blue dimer"

    SciTech Connect (OSTI)

    Concepcion, Javier J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Zhong, Diane K. [Brookhaven National Lab. (BNL), Upton, NY (United States); Szalda, David J. [Baruch College, New York, NY (United States); Muckerman, James T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Fujita, Etsuko [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-01-01

    We describe here a combined solution-surface-DFT calculations study for complexes of the type [Ru(bda)(L)?] including X-ray structure of intermediates, their reactivity, as well as pH-dependent electrochemistry and spectroelectrochemistry. These studies shed light on the mechanism of water oxidation by [Ru(bda)(L)?], revealing key features unavailable from solution studies with sacrificial oxidants.

  16. Mechanism of water oxidation by [Ru(bda)(L)?]: The return of the "blue dimer"

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

    Concepcion, Javier J.; Zhong, Diane K.; Szalda, David J.; Muckerman, James T.; Fujita, Etsuko

    2015-02-05

    We describe here a combined solution-surface-DFT calculations study for complexes of the type [Ru(bda)(L)?] including X-ray structure of intermediates, their reactivity, as well as pH-dependent electrochemistry and spectroelectrochemistry. These studies shed light on the mechanism of water oxidation by [Ru(bda)(L)?], revealing key features unavailable from solution studies with sacrificial oxidants.

  17. Adsorption dynamics and angular dependency of contaminants on Ru mirror surfaces

    E-Print Network [OSTI]

    Harilal, S. S.

    electrons from the Ru surface mainly take part in dissociating hydrocarbons and/or water molecules under EUVAdsorption dynamics and angular dependency of contaminants on Ru mirror surfaces M. Catalfano,a) A September 2011; accepted 10 December 2011; published online 6 January 2012) A real time contamination

  18. Manipulating RuBisCO accumulation in the green alga, Chlamydomonas reinhardtii

    E-Print Network [OSTI]

    Manipulating RuBisCO accumulation in the green alga, Chlamydomonas reinhardtii Xenie Johnson in algal mrl1 mutants leads to a complete absence of RuBisCO large subunit protein and thus a lack of accu between green algae (Chlamydomonas X. Johnson (&) Centre National de la Recherche Scientifique, Unite

  19. cis,cis-[(bpy)2RuV Catalyzes Water Oxidation Formally

    E-Print Network [OSTI]

    Baik, Mu-Hyun

    @indiana.edu Abstract: The mechanism of the catalytic oxidation of water by cis,cis-[(bpy)2Ru(OH2)]2O4+ to givecis,cis-[(bpy)2RuV O]2O4+ Catalyzes Water Oxidation Formally via in Situ Generation of Radicaloid molecular dioxygen was investigated using Density Functional Theory (DFT). A series of four oxidation

  20. Enhanced surface diffusion through termination conversion during epitaxial SrRuO3 growth

    E-Print Network [OSTI]

    Eom, Chang Beom

    Enhanced surface diffusion through termination conversion during epitaxial SrRuO3 growth Guus of the ferromagnetic oxide SrRuO3 on TiO2-terminated SrTiO3 , we observe a self-organized conversion of the terminating to surface termination and growth mode.6 Because their application is mostly in mirror-symmetric trilayer

  1. Metallic contacts with individual Ru nanowires prepared by electrochemical deposition and the suppression of superconductivity

    E-Print Network [OSTI]

    conducting. Nanowires of Ru were grown in commercial, track- etched polycarbonate membranes with a nominal. We have prepared Ru nanowires by electrochemical deposition in porous polycarbonate membranes on all super- conducting nanowires prepared by electrochemical deposi- tion have been limited to arrays

  2. Lab Safety: RuO4Lab Safety: RuO4 Ruthenium tetroxide is a strong oxidizing agent and must be stored in the

    E-Print Network [OSTI]

    Cohen, Robert E.

    with sodium bisulfite solution to decompose RuO4 and then flush with plenty of water. #12;Lab Safety Incompatibilities: Ammonia (chloramine gas may evolve),amines, ammonium salts, aziridine, methanol, phenyl

  3. Enhanced Thermoelectric Power and Electronic Correlations in RuSe2

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

    Wang, Kefeng; Wang, Aifeng; Tomic, A.; Wang, Limin; Abeykoon, A.M. Milinda; Dooryhee, E.; Billinge, S. J.L.; Petrovic, C.

    2015-04-01

    We report the electronic structure, electric and thermal transport properties of Ru1-xIrxSe2 (x ? 0:2). RuSe2 is a semiconductor that crystallizes in a cubic pyrite unit cell. The Seebeck coefficient of RuSe2 exceeds -200 ?#22;V/K around 730 K. Ir substitution results in the suppression of the resistivity and the Seebeck coefficient, suggesting the removal of the peaks in density of states near the Fermi level. Ru0.8Ir0.2Se2 shows a semiconductor-metal crossover at about 30 K. The magnetic field restores the semiconducting behavior. Our results indicate the importance of the electronic correlations in enhanced thermoelectricity of RuSb2.

  4. 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...

  5. High antiferromagnetic transition temperature of a honeycomb compound SrRu2O6

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

    Tian, Wei; Svoboda, Chris; Ochi, M.; Matsuda, M.; Cao, Huibo; Cheng, J. -G.; Sales, B. C.; Mandrus, D.; Arita, R.; Trivedi, Nandini; et al

    2015-09-14

    We study the high-temperature magnetic order in a quasi-two-dimensional honeycomb compound SrRu2O6 by measuring magnetization and neutron powder diffraction with both polarized and unpolarized neutrons. SrRu2O6 crystallizes into the hexagonal lead antimonate (PbSb2O6, space group P31m) structure with layers of edge-sharing RuO6 octahedra separated by Sr2+ ions. SrRu2O6 is found to order at TN = 565 K with Ru moments coupled antiferromagnetically both in plane and out of plane. The magnetic moment is 1.30(2) ?B/Ru at room temperature and is along the crystallographic c axis in the G-type magnetic structure. We perform density functional calculations with constrained random-phase approximation (RPA)more »to obtain the electronic structure and effective intra- and interorbital interaction parameters. The projected density of states shows strong hybridization between Ru 4d and O 2p. By downfolding to the target t2g bands we extract the effective magnetic Hamiltonian and perform Monte Carlo simulations to determine the transition temperature as a function of interand intraplane couplings. We find a weak interplane coupling, 3% of the strong intraplane coupling, permits three-dimensional magnetic order at the observed TN .« less

  6. Synthesis of Pd9Ru@Pt nanoparticles for oxygen reduction reaction in acidic electrolytes

    SciTech Connect (OSTI)

    Sun, Yu; Hsieh, Yu -Chi; Chang, Li -Chung; Wu, Pu -Wei; Lee, Jyh -Fu

    2014-11-22

    Nanoparticles of PdRu, Pd?Ru, and Pd?Ru are synthesized and impregnated on carbon black via a wet chemical reflux process. X-ray diffraction patterns of the as-synthesized samples, PdxRu/C (x=1/3/9), suggest succesful formation of alloy without presence of individual Pd and Ru nanoparticles. Images from transmission electron microscope confirm irregularly-shaped nanoparticles with average size below 3 nm. Analysis from extended X-ray absorption fine structure on both Pd and Ru K-edge absorption profiles indicate the Ru atoms are enriched on the surface of PdxRu/C. Among these samples, the Pd?Ru/C exhibits the strongest electrocatalytic activity for oxygen reduction reaction (ORR) in an oxygen-saturated 0.1 M aqueous HClO? solution. Subsequently, the Pd?Ru/C undegoes Cu under potential deposition, followed by a galvanic displacement reaction to deposit a Pt monolayer on the Pd?Ru surface (Pd?Ru@Pt). The Pd?Ru@Pt reveals better ORR performance than that of Pt, reaching a mass activity of 0.38 mA ?g?¹ Pt, as compared to that of commercially available Pt nanoparticles (0.107 mA ?g?¹ Pt). Thus, the mechanisms responsible for the ORR enhancement are attributed to the combined effects of lattice strain and ligand interaction. In addition, this core-shell Pd?Ru@Pt electrocatalyst represents a substantial reduction in the amount of Pt consumption and raw material cost.

  7. Synthesis of the Long-Sought Unsubstituted Aminodiboranate Na(H3B-NH2-BH3) and Its N-Alkyl Analogs

    E-Print Network [OSTI]

    Girolami, Gregory S.

    storage materials.1-9 For example, ammonia borane, NH3 ·BH3, has an especially high gravimetric hydrogen as hydrogen storage materials.15-18 In a different context, metal complexes of amino- and amidoboranes can

  8. Synthesis and thermoelectric properties of RuO{sub 2} nanorods

    SciTech Connect (OSTI)

    Music, Denis; Basse, Felix H.-U.; Schneider, Jochen M.; Hassdorf, Ralf

    2010-07-15

    We have explored the effect of the O/Ru ratio on the morphology and the Seebeck coefficient of RuO{sub 2} nanorods (space group P4{sub 2}/mnm) synthesized by reactive sputtering. At an O/Ru ratio of 1.69, a faceted surface is observed, while nanorod formation occurs at O/Ru ratios of 2.03 and 2.24. Using classical molecular dynamics with the potential parameters derived in this work, we show that volatile species enable nanorod formation. Based on ab initio calculations, two effects of the nanorod formation on the Seebeck coefficient are observed: (i) increase due to additional states in the vicinity of the Fermi level and (ii) decrease due to oxygen point defects (volatile species). These two competing effects give rise to a moderate increase in the Seebeck coefficient upon nanorod formation.

  9. , 2004, 30, . 21 12 E-mail: http://www.pnpi.spb.ru/

    E-Print Network [OSTI]

    Titov, Anatoly

    , 2004, 30, . 21 12 02 © .. , .. , .. , .. , .. .- . .. E-mail: http://www.pnpi.spb.ru/ 22 2004 . P- . , P- - . , P- , , 1% 1-. (400 ÷ 4000) Gs , P- . , M1-1 . 1 . . , 2004, 30, . 21 #12

  10. Search for 2? decays of 96Ru and 104Ru by ultra-low background HPGe gamma spectrometry at LNGS: final results

    E-Print Network [OSTI]

    P. Belli; R. Bernabei; F. Cappella; R. Cerulli; F. A. Danevich; S. d'Angelo; A. Incicchitti; G. P. Kovtun; N. G. Kovtun; M. Laubenstein; D. V. Poda; O. G. Polischuk; A. P. Shcherban; D. A. Solopikhin; J. Suhonen; V. I. Tretyak

    2013-02-28

    An experiment to search for double beta decay processes in 96Ru and 104Ru, which are accompanied by gamma rays, has been realized in the underground Gran Sasso National Laboratories of the I.N.F.N. (Italy). Ruthenium samples with masses of about (0.5-0.7) kg were measured with the help of ultra-low background high purity Ge gamma ray spectrometry. After 2162 h of data taking the samples were deeply purified to reduce the internal contamination of 40K. The last part of the data has been accumulated over 5479 h. New improved half life limits on 2\\beta+/\\epsilon \\beta+/2\\epsilon\\ processes in 96Ru have been established on the level of 10^{20} yr, in particular for decays to the ground state of 96Mo: T1/2(2\

  11. Epitaxial growth of highly conductive RuO{sub 2} thin films on (100) Si

    SciTech Connect (OSTI)

    Jia, Q.X.; Song, S.G.; Wu, X.D.; Cho, J.H.; Foltyn, S.R.; Findikoglu, A.T.; Smith, J.L.

    1996-02-01

    Conductive RuO{sub 2} thin films have been heteroepitaxially grown by pulsed laser deposition on Si substrates with yttria-stabilized zirconia (YSZ) buffer layers. The RuO{sub 2} thin films deposited under optimized processing conditions are {ital a}-axis oriented normal to the Si substrate surface with a high degree of in-plane alignment with the major axes of the (100) Si substrate. Cross-sectional transmission electron microscopy analysis on the RuO{sub 2}/YSZ/Si multilayer shows an atomically sharp interface between the RuO{sub 2} and the YSZ. Electrical measurements show that the crystalline RuO{sub 2} thin films are metallic over a temperature range from 4.2 to 300 K and are highly conductive with a room-temperature resistivity of 37{plus_minus}2 {mu}{Omega}cm. The residual resistance ratio ({ital R}{sub 300K}/{ital R}{sub 4.2K}) above 5 for our RuO{sub 2} thin films is the highest ever reported for such films on Si substrates. {copyright} {ital 1996 American Institute of Physics.}

  12. Interfacial electron transfer dynamics of ru(II)-polypy6ridine sensitized TiO2

    SciTech Connect (OSTI)

    Jakubikova, Elena [Los Alamos National Laboratory; Martin, Richard L [Los Alamos National Laboratory; Batista, Enrique R [Los Alamos National Laboratory; Snoeberger, Robert C [YALE UNIV.; Batista, Victor S [YALE UNIV.

    2009-01-01

    Quantum dynamics simulations combined with density functional theory calculations are applied to study interfacial electron transfer (IET) from pyridine-4-phosphonic acid, [Ru(tpy)(tpy(PO{sub 3}H{sub 2}))]{sup 2+} and [Ru(tpy)(bpy)(H{sub 2}O)-Ru(tpy)(tpy(PO{sub 3}H{sub 2}))]{sup 4+} into the (101) surface of anatase TiO{sub 2}. IET rate from pyridine-4-phosphonic acid attached to the nanoparticle in bidentate mode ({tau} {approx} 100 fs) is an order of magnitude faster than the IET rate of the adsorbate attached in the monodentate mode ({tau} {approx} 1 ps). Upon excitation with visible light, [Ru(tpy)(tpy(PO{sub 3}H{sub 2}))]{sup 2+} attached to TiO{sub 2} in bidentate binding mode will undergo IET with the rate of {approx} 1-10 ps, which is competitive with the excited state decay into the ground state. The probability of electron injection from [Ru(tpy)(bpy)(H{sub 2}O)-Ru(tpy)(tpy(PO{sub 3}H{sub 2}))]{sup 4+} is rather low, as the excitation with visible light localizes the excited electron in the tpy-tpy bridge, which does not have favorable coupling with the TiO{sub 2} nanoparticle. The results are relevant to better understanding of the adsorbate features important for promoting efficient interfacial electron transfer into the semiconductor.

  13. 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.

  14. High-spin structure of {sup 102}Ru

    SciTech Connect (OSTI)

    Sohler, D.; Timar, J.; Molnar, J.; Dombradi, Zs.; Krasznahorkay, A.; Zolnai, L. [Institute of Nuclear Research, H-4001 Debrecen, Pf. 51 (Hungary); Rainovski, G. [Department of Physics and Astronomy, SUNY, Stony Brook, New York, 11794-3800 (United States); Oliver Lodge Laboratory, Department of Physics, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Joshi, P.; Wadsworth, R.; Jenkins, D.G.; Raddon, P.M.; Simons, A.J.; Wilkinson, A.R. [Department of Physics, University of York, York, YO10 5DD (United Kingdom); Starosta, K. [NSCL, Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824-1321 (United States); Department of Physics and Astronomy, SUNY, Stony Brook, New York, 11794-3800 (United States); Fossan, D.B.; Koike, T.; Vaman, C. [Department of Physics and Astronomy, SUNY, Stony Brook, New York, 11794-3800 (United States); Algora, A. [Institute of Nuclear Research, H-4001 Debrecen, Pf. 51 (Hungary); Instituto de Fisica Corpuscular, E-46071 Valencia (Spain); Bednarczyk, P. [IReS, 23 rue du Loess, F-67037 Strasbourg (France); GSI, Darmstadt (Germany); Curien, D. [IReS, 23 rue du Loess, F-67037 Strasbourg (France)] [and others

    2005-06-01

    High-spin states in the nucleus {sup 102}Ru have been investigated via the {sup 96}Zr({sup 13}C,{alpha}3n) reaction at beam energies of 51 and 58 MeV, using the euroball IV {gamma}-ray spectrometer and the diamant charged particle array. Several new high-spin bands have been established. The ground-state band has been extended up to E{sub x}{approx}12 MeV with I{sup {pi}}=(26{sup +}); the previously published negative-parity bands have been extended up to E{sub x}{approx}11 and {approx} 9 MeV with I{sup {pi}}=(23{sup -}) and (20{sup -}), respectively. The deduced high-spin structure has been compared with Woods-Saxon total Routhian surface calculations and, on the basis of the measured Routhians, aligned angular momenta, and B(M1)/B(E2) ratios, {nu}h{sub 11/2}(g{sub 7/2},d{sub 5/2}) configurations are suggested for the negative-parity structures.

  15. Optical and Infrared Photometry of the Nearby Type Ia Supernovae 1999ee, 2000bh, 2000ca, and 2001ba

    E-Print Network [OSTI]

    Kevin Krisciunas; Mark M. Phillips; Nicholas B. Suntzeff; S. E. Persson; Mario Hamuy; Roberto Antezana; Pablo Candia; Alejandro Clocchiatti; Darren L. DePoy; Lisa M. Germany; Luis Gonzalez; Sergio Gonzalez; Wojtek Krzeminski; Jose Maza; Peter E. Nugent; Yulei Qiu; Armin Rest; Miguel Roth; Maximilian Stritzinger; L. -G. Strolger; Ian Thompson; T. B. Williams; Marina Wischnjewsky

    2003-11-18

    We present near infrared photometry of the Type Ia supernova 1999ee; also, optical and infrared photometry of the Type Ia SNe 2000bh, 2000ca, and 2001ba. For SNe 1999ee and 2000bh we present the first-ever SN photometry at 1.035 microns (the Y-band). We present K-corrections which transform the infrared photometry in the observer's frame to the supernova rest frame. Using our infrared K-corrections and stretch factors derived from optical photometry, we construct JHK templates which can be used to determine the apparent magnitudes at maximum if one has some data in the window -12 to +10 d with respect to T(B_max). Following up previous work on the uniformity of V minus IR loci of Type Ia supernovae of mid-range decline rates, we present unreddened loci for slow decliners. We also discuss evidence for a continuous change of color at a given epoch as a function of decline rate.

  16. Adsorption of water on O(2x2)/Ru(0001): thermal stability and inhibition of dissociation by H2O-O bonding

    E-Print Network [OSTI]

    Mugarza, Aitor

    2009-01-01

    On the O(2x2) areas intact water monomers are still visible.Adsorption of water on O(2x2)/Ru(0001): thermal stabilityJapan. Adsorption of water on O(2x2)/Ru(0001) Corresponding

  17. Achievement of high coercivity in sintered R-Fe-B magnets based on misch-metal by dual alloy method

    SciTech Connect (OSTI)

    Niu, E Wang, Zhen-Xi; Chen, Zhi-An; Rao, Xiao-Lei; Hu, Bo-Ping; Chen, Guo-An; Zhao, Yu-Gang; Zhang, Jin

    2014-03-21

    The R-Fe-B (R, rare earth) sintered magnets prepared with different ratio of alloys of MM-Fe-B (MM, misch-metal) and Nd-Fe-B by dual alloy method were investigated. As expected, the high ratio of MM-Fe-B alloy degrades the hard magnetic properties heavily with intrinsic coercivity lower than 5 kOe. When the atomic ratio MM/R???21.5% the magnetic properties can reach a practical level of B{sub r}???12.1 kGs, H{sub cj}???10.7 kOe, and (BH){sub max}???34.0 MGOe. And the effect of H{sub cj} enhancement by the grain boundary diffusion process is obvious when MM/R???21.5%. It is revealed that the decrement of intrinsic magnetic properties of R{sub 2}Fe{sub 14}B matrix phase is not the main reason of the degradation of the magnets with high MM ratio. The change of deteriorated microstructure together with phase component plays fundamental roles in low H{sub cj}. In high MM ratio magnets, (a) after annealing, Ce atoms inside main phase are inclined to be segregated in the outer layer of the main phase grains; (b) there is no thin layer of Ce-rich phase as an analogue of Nd-rich phase to separate main phase grains; (c) excessive Ce tends to form CeFe{sub 2} grains.

  18. Strain Induced Magnetism in SrRuO3 Epitaxial Thin Films

    SciTech Connect (OSTI)

    Grutter, A.; Wong, F.; Arenholz, E.; Liberati, M.; Suzuki, Y.

    2010-01-10

    Epitaxial SrRuO{sub 3} thin films were grown on SrTiO{sub 3}, (LaAlO{sub 3}){sub 0.3}(SrAlO{sub 3}){sub 0.7} and LaAlO{sub 3} substrates inducing different biaxial compressive strains. Coherently strained SrRuO{sub 3} films exhibit enhanced magnetization compared to previously reported bulk and thin film values of 1.1-1.6 {micro}{sub B} per formula unit. A comparison of (001) and (110) SrRuO{sub 3} films on each substrate indicates that films on (110) oriented have consistently higher saturated moments than corresponding (001) films. These observations indicate the importance of lattice distortions in controlling the magnetic ground state in this transitional metal oxide.

  19. On the solubility of yttrium in RuO{sub 2}

    SciTech Connect (OSTI)

    Music, Denis; Zumdick, Naemi A.; Hallstedt, Bengt; Schneider, Jochen M.

    2011-09-01

    We have investigated the solubility of Y in rutile RuO{sub 2} using experimental and theoretical methods. Nanostructured Ru-Y-O thin films were synthesized via combinatorial reactive sputtering with an O/metal ratio of 2.6 and a Y content of 0.3 to 12.6 at. %. A solubility limit of 1.7 at. % was identified using x-ray photoelectron spectroscopy and x-ray diffraction. Based on ab initio and thermodynamic modeling, the solubility of Y can be understood. Smaller Y amounts are incorporated into the lattice, forming a metastable film, with local structural deformations due to size effects. As the Y content is increased, extensive local structural deformations are observed, but phase separation does not occur due to kinetic limitations. Nanostructured RuO{sub 2} alloyed with Y might lead to enhanced phonon scattering and quantum confinement effects, which in turn improve the thermoelectric efficiency.

  20. Exploring the structure and chemical activity of 2-D gold islands on graphene moire/Ru(0001)

    E-Print Network [OSTI]

    Goodman, Wayne

    Exploring the structure and chemical activity of 2-D gold islands on graphene moire/Ru(0001) Ye Xu May 2011 DOI: 10.1039/c1fd00030f Au deposited on Ru(0001)-supported extended, continuous graphene. These Au islands conform to the corrugation of the underlying graphene and display commensurate moire

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

    SciTech Connect (OSTI)

    Thaler, Alexander

    2012-07-23

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

  2. 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

  3. 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

  4. Effects of varying CoCrV seed layer deposition pressure on Ru crystallinity in perpendicular magnetic recording media

    SciTech Connect (OSTI)

    Joost, W. [Heraeus Materials Technology, Chandler, Arizona 85226 (United States); School of Materials, Arizona State University, Tempe, Arizona 85287 (United States); Das, A. [Heraeus Materials Technology, Chandler, Arizona 85226 (United States); Alford, T. L. [School of Materials, Arizona State University, Tempe, Arizona 85287 (United States)

    2009-10-01

    The effects of varying deposition parameters of a CoCrV seed layer under Ru on the structural and interfacial properties of both layers were studied. While sputtering power showed little effect on film structure, sputtering pressure during deposition of the seed layer had a significant effect on the structural properties of the seed layer. In particular, the grain morphology and crystallinity of the seed layer varied considerably with deposition pressure. Deposition of Ru using a constant recipe for all samples demonstrated the effect of varying seed layer deposition pressure on the Ru layer. The strain energy of the Ru film, a measurement of contraction due to the registry with the seed layer, was greatest at moderate seed layer sputtering pressures, while the Ru(0002) peak area was greatest at low sputtering pressures. The competing contributions of interfacial energy and strain energy describe this effect, with interfacial energy dominating at low sputtering pressures.

  5. Heteroepitaxial growth of highly conductive metal oxide RuO{sub 2} thin films by pulsed laser deposition

    SciTech Connect (OSTI)

    Jia, Q.X.; Wu, X.D.; Foltyn, S.R.; Findikoglu, A.T.; Tiwari, P.; Zheng, J.P.; Jow, T.R.

    1995-09-18

    Highly conductive ruthenium oxide (RuO{sub 2}) has been epitaxially grown on LaAlO{sub 3} substrates by pulsed laser deposition. The RuO{sub 2} film is ({ital h}00) oriented normal to the substrate surface. The heteroepitaxial growth of RuO{sub 2} on LaAlO{sub 3} is demonstrated by the strong in-plane orientation of thin films with respect to the major axes of the substrate. High crystallinity of RuO{sub 2} thin films is also determined from Rutherford backscattering channeling measurements. Electrical measurements on the RuO{sub 2} thin films demonstrate a quite low room-temperature resistivity of 35{plus_minus}2 {mu}{Omega} cm at deposition temperatures of above 500 {degree}C. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  6. Magnetic properties of RT2Zn20; R = rare earth, T = Fe, Co, Ru, Os and Ir

    SciTech Connect (OSTI)

    Jia, Shuang

    2008-12-15

    It is well known that rare earth intermetallic compounds have versatile, magnetic properties associated with the 4f electrons: a local moment associated with the Hund's rule ground state is formed in general, but a strongly correlated, hybridized state may also appear for specific 4f electronic configuration (eg. for rare earth elements such as Ce or Yb). On the other hand, the conduction electrons in rare earth intermetallic compounds, certainly ones associated with non hybridizing rare earths, usually manifest non-magnetic behavior and can be treated as a normal, non-interacted Fermi liquid, except for some 3d-transition metal rich binary or ternary systems which often manifest strong, itinerant, d electron dominant magnetic behavior. Of particular interest are examples in which the band filling of the conduction electrons puts the system in the vicinity of a Stoner transition: such systems, characterized as nearly or weakly ferromagnet, manifest strongly correlated electronic properties [Moriya, 1985]. For rare earth intermetallic compounds, such systems provide an additional versatility and allow for the study of the behaviors of local moments and hybridized moments which are associated with 4f electron in a correlated conduction electron background.

  7. NiW and NiRu Bimetallic Catalysts for Ethylene Steam Reforming: Alternative Mechanisms for Sulfur Resistance

    SciTech Connect (OSTI)

    Rangan, M.; Yung, M. M.; Medlin, J. W.

    2012-06-01

    Previous investigations of Ni-based catalysts for the steam reforming of hydrocarbons have indicated that the addition of a second metal can reduce the effects of sulfur poisoning. Two systems that have previously shown promise for such applications, NiW and NiRu, are considered here for the steam reforming of ethylene, a key component of biomass derived tars. Monometallic and bimetallic Al{sub 2}O{sub 3}-supported Ni and W catalysts were employed for ethylene steam reforming in the presence and absence of sulfur. The NiW catalysts were less active than Ni in the absence of sulfur, but were more active in the presence of 50 ppm H{sub 2}S. The mechanism for the W-induced improvements in sulfur resistance appears to be different from that for Ru in NiRu. To probe reasons for the sulfur resistance of NiRu, the adsorption of S and C{sub 2}H{sub 4} on several bimetallic NiRu alloy surfaces ranging from 11 to 33 % Ru was studied using density functional theory (DFT). The DFT studies reveal that sulfur adsorption is generally favored on hollow sites containing Ru. Ethylene preferentially adsorbs atop the Ru atom in all the NiRu (111) alloys investigated. By comparing trends across the various bimetallic models considered, sulfur adsorption was observed to be correlated with the density of occupied states near the Fermi level while C{sub 2}H{sub 4} adsorption was correlated with the number of unoccupied states in the d-band. The diverging mechanisms for S and C{sub 2}H{sub 4} adsorption allow for bimetallic surfaces such as NiRu that enhance ethylene binding without accompanying increases in sulfur binding energy. In contrast, bimetallics such as NiSn and NiW appear to decrease the affinity of the surface for both the reagent and the poison.

  8. MgO-Supported Cluster Catalysts with Pt-Ru Interactions Prepared from Pt3Ru6(CO)21(u3-H)(u-H)3

    SciTech Connect (OSTI)

    Chotisuwan,S.; Wittapyakun, J.; Lobo-Lapidus, R.; Gates, B.

    2007-01-01

    Bimetallic MgO-supported catalysts were prepared by adsorption of Pt{sub 3}Ru{sub 6}(CO){sub 21}({mu}{sub 3}-H)({mu}-H){sub 3} on porous MgO. Characterization of the supported clusters by infrared (IR) spectroscopy showed that the adsorbed species were still in the form of metal carbonyls. The supported clusters were decarbonylated by treatment in flowing helium at 300 C, as shown by IR and extended X-ray absorption fine structure (EXAFS) data, and the resulting supported PtRu clusters were shown by EXAFS spectroscopy to have metal frames that retained Pt-Ru bonds but were slightly restructured relative to those of the precursor; the average cluster size was almost unchanged as a result of the decarbonylation. These are among the smallest reported bimetallic clusters of group-8 metals. The decarbonylated sample catalyzed ethylene hydrogenation with an activity similar to that reported previously for {gamma}-Al{sub 2}O{sub 3}-supported clusters prepared in nearly the same way and having nearly the same structure. Both samples were also active for n-butane hydrogenolysis, with the MgO-supported catalyst being more active than the {gamma}-Al{sub 2}O{sub 3}-supported catalyst.

  9. Influence of nanostructure on charge transport in RuO{sub 2} thin films

    SciTech Connect (OSTI)

    Steeves, M. M.; Lad, R. J.

    2010-07-15

    Polycrystalline thin films of RuO{sub 2} were grown on fused-quartz substrates and a parametric study was carried out to probe the influence of film nanostructure on the four-point Van der Pauw resistivity and Hall coefficient. The films were grown via reactive rf magnetron sputtering of a Ru target in an Ar/O{sub 2} plasma using deposition rates from 0.27 to 3.5 A/s and substrate temperatures from 16 to 500 deg. C Room-temperature resistivities of the RuO{sub 2} films ranged from 58 to 360 {mu}{Omega} cm. Upon first heating following deposition, some films showed decreasing resistivity with increasing temperature, but the resistivities also decreased upon subsequent cooling suggesting that the annealing treatment reduces the film defect density. The temperature coefficient of resistance was found to be small (<0.001 K{sup -1}) in agreement with previous investigations. Hall coefficient measurements of the polycrystalline thin films demonstrated that either n-type or p-type majority carriers can be present depending on deposition conditions and the resulting nanostructure, in contrast to single-crystal RuO{sub 2}, which is an n-type metal. Grain size and homogeneous strain within the films were measured by x-ray diffraction and are correlated to the majority carrier type.

  10. Tracking electron-induced carbon contamination and cleaning of Ru surfaces by Auger electron spectroscopy

    E-Print Network [OSTI]

    Harilal, S. S.

    Tracking electron-induced carbon contamination and cleaning of Ru surfaces by Auger electron that the EUV radiation induced surface contamination is associated with: (1) direct photo-dissociation in which-ray photoelectron spectroscopy (XPS) is commonly used for estimating carbon contamination in mirrors.11 However

  11. Time dependent changes in extreme ultraviolet reflectivity of Ru mirrors from electron-induced surface chemistry

    E-Print Network [OSTI]

    Harilal, S. S.

    dissociation of residual hydrocarbons plays a dominant role in the presence of additional PEs, and thus reduces degradation.2 In fact, radiation induced carbon contamination and surface oxidation have been shown to drive that the adsorption and subsequent EUV-induced dissociation of water molecules on Ru surface affect mirror performance

  12. Magnetotransport properties of doped RuSr2GdCu2O8 

    E-Print Network [OSTI]

    McCrone, J E; Tallon, J L; Cooper, J R; MacLaughlin, A C; Attfield, J. Paul; Bernhard, C

    2003-01-01

    RuSr2GdCu2O8, in which magnetic order and superconductivity coexist with Tmag>Tc , is a complex material which poses new and important questions to our understanding of the interplay between magnetic and superconducting ...

  13. The Frenkel exciton Hamiltonian for functionalized Ru(II)bpy complexes Victor V. Albert a

    E-Print Network [OSTI]

    Tretiak, Sergei

    ], artificial photo- synthesis [4], photo-detectors and sensors [5], photochemical and photovoltaic cells [6 the central Ru donor to the three bpy acceptors. The MLCT states define the photophysical and redox properties applications such as photovoltaics [6] and photocatalysis [12]. Therefore, the problem of assignment

  14. Behavior of the Ru-bda water oxidation catalyst covalently anchored on glassy carbon electrodes

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

    Matheu, Roc; Francàs, Laia; Chernev, Petko; Ertem, Mehmed Z.; Batista, Victor; Haumann, Michael; Sala, Xavier; Llobet, Antoni

    2015-05-07

    Electrochemical reduction of the dizaonium complex, [RuII(bda)(NO)(N–N2)2]3+, 23+ (N–N22+ is 4-(pyridin-4-yl) benzenediazonium and bda2– is [2,2'-bipyridine]-6,6'-dicarboxylate), in acetone produces the covalent grafting of this molecular complex onto glassy carbon (GC) electrodes. Multiple cycling voltammetric experiments on the GC electrode generates hybrid materials labeled as GC-4, with the corresponding Ru-aqua complex anchored on the graphite surface. GC-4 has been characterized at pH = 7.0 by electrochemical techniques and X-ray absorption spectroscopy (XAS) and has been shown to act as an active catalyst for the oxidation of water to dioxygen. This new hybrid material has a lower catalytic performance than its counterpartmore »in homogeneous phase and progressively decomposes to form RuO2 at the electrode surface. The resulting metal oxide attached at the GC electrode surface, GC-RuO2, is a very fast and rugged heterogeneous water oxidation catalyst with TOFis of 300 s–1 and TONs >45000. The observed performance is comparable to the best electrocatalysts reported so far, at neutral pH.« less

  15. Subsemigroups of the bicyclic monoid L. Descal co and N. Ru skuc

    E-Print Network [OSTI]

    St Andrews, University of

    Subsemigroups of the bicyclic monoid L. Descal#24;co and N. Ru#20;skuc Mathematical Institute a description of all subsemigroups of the bicyclic monoid B. We show that there are essentially #12;ve di#11 the generating set. 1 Introduction The bicyclic monoid B is de#12;ned by the presentation hb; c j bc = 1i

  16. 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...

  17. 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

  18. Synthesis and characterization of NiFe{sub 2}O{sub 4}–Pd magnetically recyclable catalyst for hydrogenation reaction

    SciTech Connect (OSTI)

    Karao?lu, E.; Özel, U.; Caner, C.; Baykal, A.; Summak, M.M.; Sözeri, H.

    2012-12-15

    Graphical abstract: Display Omitted Highlights: ? Novel superparamagnetic NiFe{sub 2}O{sub 4}–Pd magnetically recyclable catalyst was fabricated through co-precipitation. ? It could be reused several times without significant loss in catalytic activity for hydrogenation reaction. ? No further modification of the NiFe{sub 2}O{sub 4}–Pd magnetically recyclable catalyst is necessary for utilization as catalyst. -- Abstract: Herein we report the fabrication and characterization magnetically recyclable catalysts of NiFe{sub 2}O{sub 4}–Pd nanocomposite as highly effective catalysts for reduction reactions in liquid phase. The reduction Pd{sup 2+} was accomplished with polyethylene glycol 400 (PEG-400) instead of sodium borohydride (NaBH{sub 4}) and NiFe{sub 2}O{sub 4} nanoparticles was prepared by sonochemically using FeCI{sub 3}·6H{sub 2}O and NiCl{sub 2}. The chemical characterization of the product was done with X-ray diffractometry, Infrared spectroscopy, transmission electron microscopy, UV–Vis spectroscopy, thermal gravimetry and inductively coupled plasma. Thus formed NiFe{sub 2}O{sub 4}–Pd MRCs showed a very high activity in reduction reactions of 4-nitro aniline and 1,3-dinitrobenzene in liquid phase. It was found out that the catalytic activity of NiFe{sub 2}O{sub 4}–Pd MRCs on the reduction of 4-nitro aniline and 1,3-dinitrobenzene in liquid phase are between 99–93% and 98–93%, respectively. Magnetic character of this system allowed recovery and multiple use without significant loss of its catalytic activity. It is found that NiFe{sub 2}O{sub 4}–Pd MRCs showed very efficient catalytic activity and multiple usability.

  19. Oblique-incidence sputtering of Ru intermediate layer for decoupling of intergranular exchange in perpendicular recording media

    SciTech Connect (OSTI)

    Saito, Shin; Inoue, Ken; Takahashi, Migaku

    2011-04-01

    During the Ru deposition process for granular type perpendicular magnetic recording media, both a reduction in the Ru intermediate layer thickness and lowering of sputtering gas pressure were successfully achieved by focusing on a self-shadowing effect. Oblique-incidence sputtering with a 60 deg. incident angle under an Ar gas pressure of 0.6 Pa yielded (1) columnar Ru grains with a growth direction of 30 deg. from the film normal, (2) c-plane sheet texture by epitaxial growth on the Pt underlayer, and (3) a flat envelope of the surface and a deep gap at grain boundaries. This change in the Ru structure significantly contributes to reducing exchange coupling among magnetic grains, especially in the initial growth region in an overlying granular medium.

  20. Chemical Effect of Dry and Wet Cleaning of the Ru Protective Layer of the Extreme ultraviolet (EUV) Lithography Reflector

    E-Print Network [OSTI]

    Belau, Leonid

    2010-01-01

    Park, Physical Chemistry Chemical Y.B. He, et al. , JournalChemical Effect of Dry and Wet Cleaning of the Ru ProtectiveBerkeley, California 94720 Chemical Sciences Division,

  1. Low-Dimensional Water on Ru(0001); Model System for X-ray Absorption Spectroscopy Studies of Liquid Water

    E-Print Network [OSTI]

    Nordlund, D.

    2009-01-01

    nm 2 STM image of isolated water molecules (bright spots) onLow-Dimensional Water on Ru(0001); Model System forSpectroscopy Studies of Liquid Water D. Nordlund 1 , H.

  2. Impedance Studies of Ru Oxide Reduction in Sulfuric Acid Pranav P. Sharma and Ian Ivar Suni*,z

    E-Print Network [OSTI]

    Suni, Ian Ivar

    predicted by its Pourbaix diagram. Several research groups have proposed cathodic treatments prior to Cu Pourbaix diagram,8-10 which exhibits a wide potential range of stability for metallic Ru in acidic

  3. Sr{sub 4}Ru{sub 6}ClO{sub 18}, a new Ru{sup 4+/5+} oxy-chloride, solved by precession electron diffraction: Electric and magnetic behavior

    SciTech Connect (OSTI)

    Roussel, Pascal; Palatinus, Lukas; Belva, Frédéric; Daviero-Minaud, Sylvie; Mentre, Olivier; Huve, Marielle

    2014-04-01

    The crystal structure of Sr{sub 4}Ru{sub 6}ClO{sub 18}, a new Ru{sup 4+/5+} oxo-chloride, has been determined from Precession Electron Diffraction (PED) data acquired on a nanocrystal in a transmission electron microscope using the technique of electron diffraction tomography. This approach is described in details following a pedagogic route and a systematic comparison is made of this rather new method with other experimental methods of electron diffraction, and with the standard single crystal X-ray diffraction technique. Both transport and magnetic measurements, showed a transition at low temperature that may be correlated to Ru{sup 4+}/Ru{sup 5+} charge ordering. - Graphical abstract: Structure of Sr{sub 4}Ru{sub 6}ClO{sub 18}, determined using Precession Electron Diffraction data. - Highlights: • Structure of Sr{sub 4}Ru{sub 6}ClO{sub 18} was solved ab initio using precession electron diffraction. • This was done both on a nanometric sample and on a micrometric one. • Different type of experimental methods of electron diffraction are compared. • Single crystal X-ray diffraction was used to confirm the results. • Transport properties were characterized and show “exotic” behavior.

  4. 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

  5. Studies of NafionRuO2xH2O Composite Membranes Catherine Lepiller,a

    E-Print Network [OSTI]

    Hitchcock, Adam P.

    prepared by the recast method. The hydration level of RuO2·xH2O was varied by heat-dispersive X-ray analysis and scanning X-ray transmission microscopy that both show the presence of a thin layer 5 m of RuO2·xH2O on one side of the membrane. Scanning transmission X-ray microscopy also reveals

  6. Effects of Ti-Based Additives on the Hydrogen Storage Properties of aLiBH4/CaH2Destabilized System

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

    Yang, Hongwei; Ibikunle, Adeola; Goudy, Andrew J.

    2010-01-01

    The hydrogen storage properties of a destabilizedLiBH4/CaH2system ball-milled withTiCl3,TiF3, andTiO2additives have been investigated. It is found that the system withTiCl3additive has a lower dehydrogenation temperature than the ones with other additives. Further study shows that a higher amount ofTiCl3is more effective in reducing the desorption temperature of theLiBH4/CaH2system, since it leads to a lower activation energy of dehydrogenation. The activations energies for mixtures containing 4, 10, and 25?mol% ofTiCl3are 141, 126, and 110?kJ/mol, respectively. However, the benefits of higher amounts ofTiCl3are offset by a larger reduction in hydrogen capacity of the mixtures.

  7. Pulsed laser deposition and characterization of conductive RuO{sub 2} thin films

    SciTech Connect (OSTI)

    Iembo, A.; Fuso, F.; Arimondo, E.; Ciofi, C.; Pennelli, G.; Curro, G.M.; Neri, F.; Allegrini, M. |

    1997-06-01

    RuO{sub 2} thin films have been produced on silicon-based substrates by {ital in situ} pulsed laser deposition for the first time. The electrical properties, the surface characteristics, the crystalline structure, and the film-substrate interface of deposited samples have been investigated by 4-probe resistance versus temperature technique, scanning electron microscopy, x-ray photoelectron spectroscopy, x-ray diffraction, and transmission electron microscopy, respectively. The films show good electrical properties. The RuO{sub 2}-substrate interface is very thin ({approx}3 nm), since not degraded by any annealing process. These two characteristics render our films suitable to be used as electrodes in PZT-based capacitors.{copyright} {ital 1997 Materials Research Society.}

  8. Upper limit on spontaneous supercurrents in Sr2RuO4

    SciTech Connect (OSTI)

    Chung, Suk Bum

    2010-04-05

    It is widely believed that the perovskite Sr{sub 2}RuO{sub 4} is an unconventional superconductor with broken time reversal symmetry. It has been predicted that superconductors with broken time reversal symmetry should have spontaneously generated supercurrents at edges and domain walls. We have done careful imaging of the magnetic fields above Sr{sub 2}RuO{sub 4} single crystals using scanning Hall bar and SQUID microscopies, and see no evidence for such spontaneously generated supercurrents. We use the results from our magnetic imaging to place upper limits on the spontaneously generated supercurrents at edges and domain walls as a function of domain size. For a single domain, this upper limit is below the predicted signal by two orders of magnitude. We speculate on the causes and implications of the lack of large spontaneous supercurrents in this very interesting superconducting system.

  9. CALIBRATING STELLAR VELOCITY DISPERSIONS BASED ON SPATIALLY RESOLVED H-BAND SPECTRA FOR IMPROVING THE M{sub BH}-{sigma}{sub *} RELATION

    SciTech Connect (OSTI)

    Kang, Wol-Rang; Woo, Jong-Hak; Park, Daeseong; Schulze, Andreas; Riechers, Dominik A.; Kim, Sang Chul; Smolcic, Vernesa

    2013-04-10

    To calibrate stellar velocity dispersion measurements from optical and near-IR stellar lines, and to improve the black hole mass (M{sub BH})-stellar velocity dispersion ({sigma}{sub *}) relation, we measure {sigma}{sub *} based on high-quality H-band spectra for a sample of 31 nearby galaxies, for which dynamical M{sub BH} is available in the literature. By comparing velocity dispersions measured from stellar lines in the H-band with those measured from optical stellar lines, we find no significant difference, suggesting that optical and near-IR stellar lines represent the same kinematics and that dust effect is negligible for early-type galaxies. Based on the spatially resolved rotation and velocity dispersion measurements along the major axis of each galaxy, we find that a rotating stellar disk is present for 80% of galaxies in the sample. For galaxies with a rotation component, {sigma}{sub *} measured from a single aperture spectrum can vary by up to {approx}20%, depending on the size of the adopted extraction aperture. To correct for the rotational broadening, we derive luminosity-weighted {sigma}{sub *} within the effective radius of each galaxy, providing uniformly measured velocity dispersions to improve the M{sub BH}-{sigma}{sub *} relation.

  10. Characteristics of conductive SrRuO{sub 3} thin films with different microstructures

    SciTech Connect (OSTI)

    Jia, Q.X.; Chu, F.; Adams, C.D.; Wu, X.D.; Hawley, M.; Cho, J.H.; Findikoglu, A.T.; Foltyn, S.R.; Smith, J.L.; Mitchell, T.E.

    1996-09-01

    Conductive SrRuO{sub 3} thin films were epitaxially grown on (100) LaAlO{sub 3} substrates by pulsed laser deposition over a temperature range from 650{degree}C to 825{degree}C. Well-textured films exhibiting a strong orientation relationship to the underlying substrate could be obtained at a deposition temperature as low as 450{degree}C. The degree of crystallinity of the films improved with increasing deposition temperature as confirmed by x-ray diffraction, transmission electron microscopy, and scanning tunneling microscopy. Scanning electron microscopy revealed no particulates on the film surface. The resistivity of the SrRuO{sub 3} thin films was found to be a strong function of the crystallinity of the film and hence the substrate temperature during film deposition. A residual resistivity ratio (RRR={rho}{sub 300K}/{rho}{sub 4.2K}) of more than 8 was obtained for the SrRuO{sub 3} thin films deposited under optimized processing conditions. {copyright} {ital 1996 Materials Research Society.}

  11. Manipulating Magnetism: Ru-2(5+) Paddlewheels Devoid of Axial Interactions

    SciTech Connect (OSTI)

    Chiarella, Gina M [Texas A& M University; Cotton, F. A. [Texas A& M University; Murillo, Carlos A [Texas A& M University; Ventura, Karen [University of Texas at El Paso; Vilagran, Dino [University of Texas at El Paso; Wang, Xiaoping [ORNL

    2014-01-01

    Variable-temperature magnetic and structural data of two pairs of diruthenium isomers, one pair having an axial ligand and the formula Ru-2(DArF)(4)Cl (where DArF is the anion of a diarylformamidine isomer and Ar = p-anisyl or m-anisyl) and the other one being essentially identical but devoid of axial ligands and having the formula [Ru-2(DArF)(4)]BF4, show that the axial ligand has a significant effect on the electronic structure of the diruthenium unit. Variable temperature crystallographic and magnetic data as well as density functional theory calculations unequivocally demonstrate the occurrence of pi interactions between the p orbitals of the chlorine ligand and the pi* orbitals in the Ru-2(5+) units. The magnetic and structural data are consistent with the existence of combined ligand sigma/metal sigma and ligand p pi/metal-d pi interactions. Electron paramagnetic resonance data show unambiguously that the unpaired electrons are in metal-based molecular orbitals.

  12. Microsoft Word - spintronics bh

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

    other using much less energy, as essentially no heat is generated, ultimately making spintronic devices more energy efficient. Evidently, to generate and manipulate spin currents...

  13. Microsoft Word - spintronics bh

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformationJessework uses concrete7 Assessment ofLana7, at 3:00 pmQuark

  14. Features of the band structure and conduction mechanisms in the n-HfNiSn semiconductor heavily doped with Ru

    SciTech Connect (OSTI)

    Romaka, V. A.; Rogl, P.; Romaka, V. V.; Stadnyk, Yu. V.; Korzh, R. O.; Krayovskyy, V. Ya.; Horyn, A. M.

    2014-12-15

    The crystal and electronic structure and energy and kinetic properties of the n-HfNiSn semiconductor heavily doped with a Ru acceptor impurity are investigated in the temperature and Ru concentration ranges T = 80–400 K and N{sub A}{sup Ru} ? 9.5 × 10{sup 19}?5.7 × 10{sup 20} cm{sup ?3} (x = 0–0.03), respectively. The mechanism of structural-defect generation is established, which changes the band gap and degree of compensation of the semiconductor and consists in the simultaneous concentration reduction and elimination of donor structural defects by means of the displacement of ?1% of Ni atoms from the Hf (4a) positions, the generation of acceptor structural defects upon the substitution of Ru atoms for Ni atoms in the 4c positions, and the generation of donor defects in the form of vacancies in the Sn (4b) positions. The calculated electronic structure of HfNi{sub 1?x}Ru{sub x}Sn is consistent with the experiment. The results obtained are discussed within the Shklovsky-Efros model for a heavily doped and compensated semiconductor.

  15. Incoherent Bi off-centering in Bi?Ti?O?O' and Bi?Ru?O?O': Insulator versus metal

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

    Shoemaker, Daniel P.; Seshadri, Ram; Tachibana, Makoto; Hector, Andrew L.

    2011-08-01

    In the cubic, stoichiometric oxide compounds Bi?Ti?O?O' (also written as Bi?Ti?O?) and Bi?Ru?O?O' (also written as Bi?Ru?O?) Bi³? ions on the pyrochlore A site display a propensity to off-center. Unlike Bi?Ti?O?O', Bi?Ru?O?O' is a metal, so it is of interest to ask whether conduction electrons and/or involvement of Bi 6s states at the Fermi energy influence Bi³? displacements. The Bi³? off-centering in Bi?Ti?O?O' has previously been revealed to be incoherent from detailed reverse Monte Carlo analysis of total neutron scattering. Similar analysis of Bi?Ru?O?O' reveals incoherent off-centering as well, but of smaller magnitude and with distinctly different orientational preference. Analysismore »of the distributions of metal to oxygen distances presented suggests that Bi in both compounds is entirely Bi³?. Disorder in Bi?Ti?O?O' has the effect of stabilizing valence while simultaneously satisfying the steric constraint imposed by the presence of the lone pair of electrons. In Bi?Ru?O?O', off-centering is not required to satisfy valence and seems to be driven by the lone pair. Decreased volume of the lone pair may be a result of partial screening by conduction electrons.« less

  16. 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.

  17. Ultrafast Magnetization Dynamics of SrRuO3 Thin Films

    SciTech Connect (OSTI)

    Langner, Matthew C

    2009-05-19

    Itinerant ferromagnet SrRuO3 has drawn interest from physicists due to its unusual transport and magnetic properties as well as from engineers due to its low resistivity and good lattice-matching to other oxide materials. The exact electronic structure remains a mystery, as well as details of the interactions between magnetic and electron transport properties. This thesis describes the use of time-resolved magneto-optical Kerr spectroscopy to study the ferromagnetic resonance of SrRuO3 thin films, where the ferromagnetic resonance is initiated by a sudden change in the easy axis direction in response to a pump pulse. The rotation of the easy axis is induced by laser heating, taking advantage of a temperature-dependent easy axis direction in SrRuO3 thin films. By measuring the change in temperature of the magnetic system in response to the laser pulse, we find that the specific heat is dominated by magnons up to unusually high temperature, ~;;100 K, and thermal diffusion is limited by a boundary resistance between the film and the substrate that is not consistent with standard phonon reflection and scattering models. We observe a high FMR frequency, 250 GHz, and large Gilbert damping parameter, alpha ~;; 1, consistent with strong spin-orbit coupling. We observe a time-dependent change in the easy axis direction on a ps time-scale, and we find that parameters associated with the change in easy axis, as well as the damping parameter, have a non-monotonic temperature dependence similar to that observed in anomalous Hall measurements.

  18. Time-Resolved XAFS Spectroscopic Studies of B-H and N-H Oxidative Addition to Transition Metal Catalysts Relevant to Hydrogen Storage

    SciTech Connect (OSTI)

    Bitterwolf, Thomas E.

    2014-12-09

    Successful catalytic dehydrogenation of aminoborane, H3NBH3, prompted questions as to the potential role of N-H oxidative addition in the mechanisms of these processes. N-H oxidative addition reactions are rare, and in all cases appear to involve initial dative bonding to the metal by the amine lone pairs followed by transfer of a proton to the basic metal. Aminoborane and its trimethylborane derivative block this mechanism and, in principle, should permit authentic N-H oxidative attrition to occur. Extensive experimental work failed to confirm this hypothesis. In all cases either B-H complexation or oxidative addition of solvent C-H bonds dominate the chemistry.

  19. Critical Thickness for Itinerant Ferromagnetism in Ultrathin Films of SrRuO_3

    SciTech Connect (OSTI)

    Xia, Jing

    2010-04-05

    Ultrathin films of the itinerant ferromagnet SrRuO{sub 3} were studied using transport and magneto-optic polar Kerr effect. We find that below 4 monolayers the films become insulating and their magnetic character changes as they loose their simple ferromagnetic behavior. We observe a strong reduction in the magnetic moment which for 3 monolayers and below lies in the plane of the film. Exchange-bias behavior is observed below the critical thickness, and may point to induced antiferromagnetism in contact with ferromagnetic regions.

  20. A tentative classification of the bya ru can kings of Zhang zhung

    E-Print Network [OSTI]

    Vitali, Roberto

    2008-01-01

    ; Kha yug; Kha sgyor; the areas of Da rog/Ta rog mtsho and sTa sgo ; La dwags and Ru thog. 21 The transmission of Phur pa’i Bon (dPal ldan tshul khrims, bsTan ’byung skal bzang mgul rgyan p. 107 line... 18-19) says: “sPyod pa ni Bod la bya khyur ltar myul”; “The behaviour [of the king of sTag gzig] is to make reconnaissance in Bod like [a hawk] into a flock of birds”; finally mKhas pa’i dga’ ston (p. 156 line 8) writes: “sTag gzig rgyal po bya...

  1. BIG RU N INDIANA LAKESHORE RUN E LUMBER CIT Y WARSAW JOHNST

    Gasoline and Diesel Fuel Update (EIA)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustments (Billion Cubic Feet) Wyoming Dry NaturalPrices1 Table 1.101 (Million Short6RU N INDIANA LAKESHORE RUN

  2. BIG RU N INDIANA LAKESHORE RUN E LUMBER CIT Y WARSAW JOHNST

    Gasoline and Diesel Fuel Update (EIA)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustments (Billion Cubic Feet) Wyoming Dry NaturalPrices1 Table 1.101 (Million Short6RU N INDIANA LAKESHORE

  3. BIG RU N INDIANA LAKESHORE RUN E LUMBER CIT Y WARSAW JOHNST

    Gasoline and Diesel Fuel Update (EIA)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustments (Billion Cubic Feet) Wyoming Dry NaturalPrices1 Table 1.101 (Million Short6RU N INDIANA

  4. Coupling reactions of phenylacetylene with water, hydrogen sulfide and primary amines mediated by a Ru(II) phenylvinylidene complex

    SciTech Connect (OSTI)

    Bianchini, C.; Peruzzini, M.; Zanobini, F. [Istituto per lo Studio della Stereochimica ed Energetica dei Composti di Coordinazione, Florence (Italy)] [and others

    1995-12-31

    The Ru(II) fragment [(PNP)RuCl{sub 2}] assists the reaction of phenylacetylene with water, hydrogen sulfide and primary amines to give carbonyl, {eta}{sup 1}-benzylthioaldehyde, and isonitrile complexes, respectively [PNP = CH{sub 3}CH{sub 2}CH{sub 2}N(CH{sub 2}CH{sub 2}PPh{sub 2}){sub 2}]. In all of these processes, the reaction is initiated by the 1-alkyne to vinylidene tautomerization at the Ru(II) center, followed by attack of the H{sub 2}Z molecule (Z = O, S, NR) on the vinylidene ligand. The mechanisms which account for these transformations have been completely elucidated and several of the intermediates in these reactions have been isolated and fully characterized. The scope of these reactions in view of their potential applications in organic syntheses involving thioaldehydes and optically pure isonitriles will be briefly presented.

  5. Self-calibration of a W/Re thermocouple using a miniature Ru-C (1954 °C) eutectic cell

    SciTech Connect (OSTI)

    Ongrai, O. [National Physical Laboratory (NPL), Hampton Road, Teddington, Middlesex (United Kingdom) [National Physical Laboratory (NPL), Hampton Road, Teddington, Middlesex (United Kingdom); University of Surrey, Guildford, Surrey (United Kingdom); National Institute of Metrology, Klong 5, Klong Luang, Pathumthani (Thailand); Pearce, J. V.; Machin, G. [National Physical Laboratory (NPL), Hampton Road, Teddington, Middlesex (United Kingdom)] [National Physical Laboratory (NPL), Hampton Road, Teddington, Middlesex (United Kingdom); Sweeney, S. J. [University of Surrey, Guildford, Surrey (United Kingdom)] [University of Surrey, Guildford, Surrey (United Kingdom)

    2013-09-11

    Previous successful investigations of miniature cobalt-carbon (Co-C, 1324 °C) and palladium-carbon (Pd-C, 1492 °C) high temperature fixed-point cells for thermocouple self-calibration have been reported [1-2]. In the present work, we describe a series of measurements of a miniature ruthenium-carbon (Ru-C) eutectic cell (melting point 1954 °C) to evaluate the repeatability and stability of a W/Re thermocouple (type C) by means of in-situ calibration. A miniature Ru-C eutectic fixed-point cell with outside diameter 14 mm and length 30 mm was fabricated to be used as a self-calibrating device. The performance of the miniature Ru-C cell and the type C thermocouple is presented, including characterization of the stability, repeatability, thermal environment influence, ITS-90 temperature realization and measurement uncertainty.

  6. Coupled Nd and B' spin ordering in the double perovskites Nd2NaB'O6 (B' = Ru, Os)

    SciTech Connect (OSTI)

    Aczel, Adam A [ORNL; Bugaris, Dan [University of South Carolina; Yeon, Jeongho [University of South Carolina, Columbia; Dela Cruz, Clarina R [ORNL; Zur Loye, Hans-Conrad [University of South Carolina; Nagler, Stephen E [ORNL

    2013-01-01

    We present a neutron powder diffraction study of the monoclinic double perovskite systems Nd$_2$NaB$'$O$_6$ (B$'$~$=$~Ru, Os), with magnetic atoms occupying both the A and B$'$ sites. Our measurements reveal coupled spin ordering between the Nd and B$'$ atoms with magnetic transition temperatures of 14~K for Nd$_2$NaRuO$_6$ and 16~K for Nd$_2$NaOsO$_6$. There is a Type I antiferromagnetic structure associated with the Ru and Os sublattices, with the ferromagnetic planes stacked along the c-axis and [110] direction respectively, while the Nd sublattices exhibit complex, canted antiferromagnetism with different spin arrangements in each system.

  7. Studies on catalytic and structural properties of BaRuO3 type perovskite1 material for diesel soot oxidation2

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Studies on catalytic and structural properties of BaRuO3 type perovskite1 material for diesel by co-precipitation24 method and its catalytic activity has been tested for diesel soot oxidation processes and vehicle exhaust.33 Key words: BaRuO3, perovskite, diesel soot oxidation, vehicular exhaust

  8. Multifold Seebeck increase in RuO{sub 2} films by quantum-guided lanthanide dilute alloying

    SciTech Connect (OSTI)

    Music, Denis Basse, Felix H.-U.; Schneider, Jochen M.; Han, Liang; Borca-Tasciuc, Theo; Devender; Gengler, Jamie J.; Voevodin, Andrey A.; Ramanath, Ganpati

    2014-02-03

    Ab initio predictions indicating that alloying RuO{sub 2} with La, Eu, or Lu can increase the Seebeck coefficient ? manifold due to quantum confinement effects are validated in sputter-deposited La-alloyed RuO{sub 2} films showing fourfold ? increase. Combinatorial screening reveals that ? enhancement correlates with La-induced lattice distortion, which also decreases the thermal conductivity twentyfold, conducive for high thermoelectric figures of merit. These insights should facilitate the rational design of high efficiency oxide-based thermoelectrics through quantum-guided alloying.

  9. Strain relaxation in epitaxial SrRuO{sub 3} thin films on LaAlO{sub 3} substrates

    SciTech Connect (OSTI)

    Gao, M.; Du, H.; Dai, C.; Lin, Y. [State Key Laboratory of Electronic Thin films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054 (China)] [State Key Laboratory of Electronic Thin films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054 (China); Ma, C. R.; Liu, M.; Collins, G.; Zhang, Y. M.; Chen, C. L. [Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, Texas 78249, USA and Department of Physics and The Texas Center for Superconductivity, University of Houston, Houston, Texas 77204 (United States)] [Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, Texas 78249, USA and Department of Physics and The Texas Center for Superconductivity, University of Houston, Houston, Texas 77204 (United States)

    2013-09-30

    Strain relaxation behavior of epitaxial SrRuO{sub 3} thin films on (001) LaAlO{sub 3} substrates was investigated using high resolution X-ray diffraction. Lattice distortion and dislocation densities were systematically studied with samples under different growth conditions. Reciprocal space maps reveal different strain relaxation behavior in SrRuO{sub 3} thin films grown at different temperatures. Two kinds of strain relaxation mechanisms were proposed to understand the growth dynamics, including the evolution of threading dislocations and the tilt of crystalline planes.

  10. Growth of epitaxial (Sr,Ba){sub n+1}Ru{sub n}O{sub 3n+1} films

    SciTech Connect (OSTI)

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

    1997-12-01

    We have grown epitaxial (Sr,Ba) (n+1)Ru(n)O(3n+1) films, n = 1, 2, and infinity, by pulsed laser deposition (PLD) and controlled their orientation by choosing appropriate substrates. The growth conditions yielding phase pure films have been mapped out. Resistivity versus temperature measurements show that both a and c axis films of Sr2RuO4 are metallic, but not superconducting. The latter is probably due to the presence of low-level impurities that are difficult to avoid given the target preparation process involved in growing these films by PLD.

  11. Spin-lozenge thermodynamics and magnetic excitations in Na3RuO4

    SciTech Connect (OSTI)

    Haraldsen, Jason T; Stone, Matthew B; Lumsden, Mark D; Barnes, Ted {F E }; Jin, Rongying; Taylor, J. W.; Fernandez-Alonso, F

    2009-01-01

    We report inelastic and elastic neutron scattering, magnetic susceptibility, and heat capacity measurements of polycrystalline sodium ruthenate (Na3RuO4). Previous work suggests this material consists of isolated tetramers of S = 3/2 Ru5+ ions in a so-called lozenge configuration. Using a Heisenberg antiferromagnet Hamiltonian, we analytically determine the energy eigenstates for general spin S. From this model, the neutron scattering cross-sections for excitations associated with spin-3/2 tetramer configurations is determined. Comparison of magnetic susceptibility and inelastic neutron scattering results shows that the proposed lozenge model is not distinctly supported, but provides evidence that the system may be better described as a pair of non-interacting inequivalent dimers, i.e double dimers. However, the existence of long-range magnetic order below Tc ? 28 K immediately questions such a description. Although no evidence of the lozenge model is observed, future studies on single crystals may further clarify the appropriate magnetic Hamiltonian.

  12. Evaluation of the Geotech SMART24BH 20Vpp/5Vpp data acquisition system with active fortezza crypto card data signing and authentication.

    SciTech Connect (OSTI)

    Rembold, Randy Kai; Hart, Darren M.

    2009-09-01

    Sandia National Laboratories has tested and evaluated Geotech SMART24BH borehole data acquisition system with active Fortezza crypto card data signing and authentication. The test results included in this report were in response to static and tonal-dynamic input signals. Most test methodologies used were based on IEEE Standards 1057 for Digitizing Waveform Recorders and 1241 for Analog to Digital Converters; others were designed by Sandia specifically for infrasound application evaluation and for supplementary criteria not addressed in the IEEE standards. The objective of this work was to evaluate the overall technical performance of two Geotech SMART24BH digitizers with a Fortezza PCMCIA crypto card actively implementing the signing of data packets. The results of this evaluation were compared to relevant specifications provided within manufacturer's documentation notes. The tests performed were chosen to demonstrate different performance aspects of the digitizer under test. The performance aspects tested include determining noise floor, least significant bit (LSB), dynamic range, cross-talk, relative channel-to-channel timing, time-tag accuracy/statistics/drift, analog bandwidth.

  13. Influence of oxide impurities on the chemical tuning of the thermoelectric properties of substitution derivatives of RuIn{sub 3}

    SciTech Connect (OSTI)

    Wagner-Reetz, Maik, E-mail: Maik.Wagner@cpfs.mpg.de; Cardoso-Gil, Raul; Schmidt, Marcus; Grin, Yuri, E-mail: Juri.Grin@cpfs.mpg.de

    2014-07-01

    A systematic investigation on tuning the charge carrier concentration by substitution of the Ru position in RuIn{sub 3} is performed. Samples with nominal composition Ru{sub 0.95}T{sub 0.05}In{sub 3} (T=Re, Rh, Ir) were synthesized via liquid–solid-reaction and subsequent spark plasma sintering treatment. The chemical composition was characterized by X-ray, metallographic and microstructure analysis revealing solid solutions in the samples with Rh and Ir, whereas Re cannot be incorporated in RuIn{sub 3}. Minor oxide impurities in the commercially available starting elements, the homogeneity range of RuIn{sub 3} and the redox potentials of the participating elements are the key for interpreting the observed lattice parameters and the corresponding composition. Both, substitutions with Rh or Ir and Re inclusions in RuIn{sub 3} lead independently to a significant decrease of the total thermal conductivity down to approximately one half of the value observed for binary RuIn{sub 3}, prepared with commercially available starting materials. The electrical resistivity was reduced by substitution and the temperature dependence changes from semiconductor-like, for RuIn{sub 3}, to metal-like in the substitution derivatives. At the same time the sign change in the thermopower at high temperatures, characteristic for binary RuIn{sub 3}, is suppressed, attaining only electrons as majority carriers. - Graphical abstract: Microstructure (perpendicular to the pressure axis; polarized light) of polycrystalline Ru{sub 0.95}Rh{sub 0.05}In{sub 3} (a), Ru{sub 0.95}Ir{sub 0.05}In{sub 3} (b) and Ru{sub 0.95}Re{sub 0.05}In{sub 3} (c) samples after SPS treatment. - Highlights: • Substitution solid solutions of RuIn{sub 3} were prepared via liquid–solid-reaction. • Chemistry of oxide impurities is crucial for explanation of experimental results. • Thermodynamic calculations support the observation of In{sub 2}O{sub 3} or ZnO as impurities. • Electrical resistivity is reduced by substitution. • Temperature dependence of resistivity changes from semiconductor- to metal-like.

  14. 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

  15. Metalloproteins: Structure Determination (HADH), Inhibition (P4H), and Biomimetic Systems (P-1[Ru(NO)(Cl)])

    E-Print Network [OSTI]

    Reed, Timothy M.

    2008-01-01

    .2. xi Figure 4.8. Time release curve of P-1[Ru(NO)(Cl) with continuous 200 release (black dots) and stop time relase (red dots). Stop time relase is demonstrated with continuous iradiation (solid line) and no iradiation (dashed line). Figure 4...

  16. UBC Social Ecological Economic Development Studies (SEEDS) Student Report Ben Duenas, Chen Ling, Neona Chan, Yi Ru Soh

    E-Print Network [OSTI]

    categories: solvent/oil waste (halogenated, non- halogenated and oils), non-regulated contaminated solid, Neona Chan, Yi Ru Soh Quantifying Water Content for Non-halogenated Waste Solvents CHBE 464 March 24 Problem-Based Laboratory: Final Report Quantifying Water Content for Non-halogenated Waste Solvents March

  17. XMM-Newton observations of the dwarf nova RU Peg in quiescence: Probe of the boundary layer

    E-Print Network [OSTI]

    Balman, S; Sion, E M; Ness, J -U; Schlegel, E; Barrett, P E; Szkody, P

    2011-01-01

    We present an analysis of X-ray and UV data obtained with the XMM-Newton Observatory of the long period dwarf nova RU Peg. RU Peg contains a massive white dwarf, possibly the hottest white dwarf in a dwarf nova, it has a low inclination, thus optimally exposing its X-ray emitting boundary layer, and has an excellent trigonometric parallax distance. We modeled the X-ray data using XSPEC assuming a multi-temperature plasma emission model built from the MEKAL code. We obtained a maximum temperature of 31.7 keV, based on the EPIC MOS1, 2 and pn data, indicating that RU Peg has an X-ray spectrum harder than most dwarf novae, except U Gem. This result is consistent with and indirectly confirms the large mass of the white dwarf in RU Peg. The X-ray luminosity we computed corresponds to a boundary layer luminosity for a mass accretion rate of 2.E-11 Msun/yr (assuming Mwd=1.3Msun), in agreement with an expected quiescent accretion rate. The modeling of the O VIII emission line at 19A as observed by the RGS implies a p...

  18. Highly efficient electrochemiluminescence from Ru,,II... complex with PEO-PHP-PEO as a buffer layer

    E-Print Network [OSTI]

    Wan, Xin-hua

    CF3SO3 was introduced into light-emitting electrochemical cells. The response rate and efficiency of indium tin oxide/PEO-PHP-PEO LiCF3SO3 / Ru bpy 3 PF6 2/Au, showed a turn-on voltage as low as 2.85 V

  19. 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

  20. CO2 Reduction on Supported Ru/Al2O3 Catalysts: Cluster Size Dependence of Product Selectivity

    SciTech Connect (OSTI)

    Kwak, Ja Hun; Kovarik, Libor; Szanyi, Janos

    2013-11-01

    The catalytic performance of a series of Ru/Al2O3 catalysts with Ru content in the 0.1-5% range was examined in the reduction of CO2 with H2. At low Ru loadings (?0.5 %) where the active metal phase is highly dispersed (mostly atomically) on the alumina support CO is formed with high selectivity. With increasing metal loading the selectivity toward CH4 formation increases, while that for CO production decreases. In the 0.1% Ru/Al2O3 catalyst Ru is mostly present in atomic dispersion as STEM images obtained from the fresh sample prior to catalytic testing reveal. STEM images recorded form this same sample following temperature programmed reaction test clearly show the agglomeration of small metal particles (and atoms) into 3D clusters. The clustering of the highly dispersed metal phase is responsible for the observed dramatic selectivity change during elevated temperature tests: dramatic decrease in CO, and large increase in CH4 selectivity. Apparent activation energies, estimated from the slopes of Arrhenius plots, of 82 kJ/mol and 62 kJ/mol for CO and CH4 formation were determined, respectively, regardless of Ru loading. These results suggest that the formation of CO and CH4 follow different reaction pathways, or proceed on active centers of different nature. Reactions with CO2/H2 and CO/H2 mixtures (under otherwise identical reaction conditions) reveal that the onset temperature of CO2 reduction is about 150 ºC lower than of CO reduction. We thank Dr. Feng Gao for carrying out the H2 chemisorption measurements on all the Ru/Al2O3 catalysts discussed in this work. The catalyst preparation and catalytic measurements were supported by a Laboratory Directed Research and Development (LDRD) project, while the TEM work was supported by the Chemical Imaging Initiative at the Pacific Northwest National Laboratory (PNNL). PNNL is operated for the US Department of Energy by Battelle under contract number DE-AC05-76RL01830. JHK also acknowledges the support of this work by the 2013 Research Fund of UNIST (Ulsan National Institute of Science and Technology, Ulsan, Korea).

  1. [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...

  2. 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

  3. Synthesis and Characterization of RuO2/poly (3,4-ethylenedioxythiophene) (PEDOT) Composite Nanotubes for Supercapacitors

    SciTech Connect (OSTI)

    Liu, Ran; Duay, Jonathon; Lane, Timothy; Lee, Sang Bok

    2010-01-18

    We report the synthesis of composite RuO2/poly(3,4-ethylenedioxythiophene) (PEDOT) nanotubes with high specific capacitance and fast charging/discharging capability as well as their potential application as electrode materials for a high-energy and high-power supercapacitor. RuO2/PEDOT nanotubes were synthesized in a porous alumina membrane by a step-wise electrochemical deposition method, and their structures were characterized using electron microscopy. Cyclic voltammetry was used to qualitatively characterize the capacitive properties of the composite RuO2/PEDOT nanotubes. Their specific capacitance, energy density and power density were evaluated by galvanostatic charge/discharge cycles at various current densities. The pseudocapacitance behavior of these composite nanotubes originates from ion diffusion during the simultaneous and parallel redox processes of RuO2 and PEDOT. We show that the energy density (specific capacitance) of PEDOT nanotubes can be remarkably enhanced by electrodepositing RuO2 into their porous walls and onto their rough internal surfaces. The flexible PEDOT prevents the RuO2 from breaking and detaching from the current collector while the rigid RuO2 keeps the PEDOT nanotubes from collapsing and aggregating. The composite RuO2/PEDOT nanotube can reach a high power density of 20 kW kg-1 while maintaining 80% energy density (28 Wh kg-1) of its maximum value. This high power capability is attributed to the fast charge/discharge of nanotubular structures: hollow nanotubes allow counter-ions to readily penetrate into the composite material and access their internal surfaces, while a thin wall provides a short diffusion distance to facilitate ion transport. The high energy density originates from the RuO2, which can store high electrical/electrochemical energy intrinsically. The high specific capacitance (1217 Fg-1) which is contributed by the RuO2 in the composite RuO2/PEDOT nanotube is realized because of the high specific surface area of the nanotubular structures. Such PEDOT/RuO2 composite nanotube materials are an ideal candidate for the development of high-energy and high-power supercapacitors.

  4. 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

  5. Thickness-dependent metal-insulator transition in epitaxial SrRuO? ultrathin films

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

    Shen, Xuan; Qiu, Xiangbiao; Su, Dong; Zhou, Shengqiang; Li., Aidong; Wu, Di

    2015-01-06

    Transport characteristics of ultrathin SrRuO? films, deposited epitaxially on TiO?-terminated SrTiO? (001) single-crystal substrates, were studied as a function of film thickness. Evolution from a metallic to an insulating behavior is observed as the film thickness decreases from 20 to 4 unit cells. In films thicker than 4 unit cells, the transport behavior obeys the Drude low temperature conductivity with quantum corrections, which can be attributed to weak localization. Fitting the data with 2-dimensional localization model indicates that electron-phonon collisions are the main inelastic relaxation mechanism. In the film of 4 unit cells in thickness, the transport behavior follows variablemore »range hopping model, indicating a strongly localized state. Magnetoresistance measurements reveal a likely magnetic anisotropy with the magnetic easy axis along the out-of-plane direction.« less

  6. Thickness-dependent metal-insulator transition in epitaxial SrRuO3 ultrathin films

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

    Shen, Xuan; Qiu, Xiangbiao; Su, Dong; Zhou, Shengqiang; Li, Aidong; Wu, Di

    2015-01-06

    Transport characteristics of ultrathin SrRuO? films, deposited epitaxially on TiO?-terminated SrTiO? (001) single-crystal substrates, were studied as a function of film thickness. Evolution from a metallic to an insulating behavior is observed as the film thickness decreases from 20 to 4 unit cells. In films thicker than 4 unit cells, the transport behavior obeys the Drude low temperature conductivity with quantum corrections, which can be attributed to weak localization. Fitting the data with 2-dimensional localization model indicates that electron-phonon collisions are the main inelastic relaxation mechanism. In the film of 4 unit cells in thickness, the transport behavior follows variablemore »range hopping model, indicating a strongly localized state. As a result, magnetoresistance measurements reveal a likely magnetic anisotropy with the magnetic easy axis along the out-of-plane direction.« less

  7. Thickness-dependent metal-insulator transition in epitaxial SrRuO? ultrathin films

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

    Shen, Xuan [Nanjing Univ. (China); Brookhaven National Lab. (BNL), Upton, NY (United States); Qiu, Xiangbiao [Nanjing Univ. (China); Su, Dong [Brookhaven National Lab. (BNL), Upton, NY (United States); Zhou, Shengqiang [Inst. of Ion Beam Physics and Materials Research, Dresden (Germany); Li., Aidong [Nanjing Univ. (China); Wu, Di [Nanjing Univ. (China)

    2015-01-07

    Transport characteristics of ultrathin SrRuO? films, deposited epitaxially on TiO?-terminated SrTiO? (001) single-crystal substrates, were studied as a function of film thickness. Evolution from a metallic to an insulating behavior is observed as the film thickness decreases from 20 to 4 unit cells. In films thicker than 4 unit cells, the transport behavior obeys the Drude low temperature conductivity with quantum corrections, which can be attributed to weak localization. Fitting the data with 2-dimensional localization model indicates that electron-phonon collisions are the main inelastic relaxation mechanism. In the film of 4 unit cells in thickness, the transport behavior follows variable range hopping model, indicating a strongly localized state. Magnetoresistance measurements reveal a likely magnetic anisotropy with the magnetic easy axis along the out-of-plane direction.

  8. Investigation of double beta decay of $^{100}$Mo to excited states of $^{100}$Ru

    E-Print Network [OSTI]

    R. Arnold; C. Augier; A. S. Barabash; . ..

    2014-02-28

    Double beta decay of $^{100}$Mo to the excited states of daughter nuclei has been studied using a 600 cm$^3$ low-background HPGe detector and an external source consisting of 2588 g of 97.5% enriched metallic $^{100}$Mo, which was formerly inside the NEMO-3 detector and used for the NEMO-3 measurements of $^{100}$Mo. The half-life for the two-neutrino double beta decay of $^{100}$Mo to the excited 0$^+_1$ state in $^{100}$Ru is measured to be $T_{1/2}=[7.5 \\pm{0.6}(stat) \\pm {0.6}(syst)]\\cdot 10^{20}$ yr. For other $(0\

  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. Magnetic hardening of Ce1+xFe11–yCoyTi with ThMn12 structure by melt spinning

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

    Zhou, Chen; Sun, Kewei; Pinkerton, Frederick E.; Kramer, M. J.

    2015-04-15

    A recent study on the intrinsic magnetic properties of CeFe11–yCoyTi has revealed that substituting one Co for Fe retains the favorable magnetocrystalline anisotropy Ha found in the ternary Fe end member, while enhancing the Curie temperature Tc and saturation magnetization 4?Ms. These findings warrant further optimization around Co substitution y = 1 to try to exploit the hard magnetic properties of these Ce-based magnets. Both Ce and Co concentrations in Ce1+xFe11–yCoyTi have been optimized in the range of x = 0 – 0.2 and y = 0 –1.5. It was found that Co substitution effectively enhances all hard magnetic properties,more »although the values are still lower than those predicted from the intrinsic magnetic properties. Specifically, Tc increases from 210 °C to 285 – 350 °C; 4?M19 (magnetization at 19 kOe) from 8.9 kG to 10.5 – 11.5 kG, remanence Br from 3.1 kG to 4.1 – 4.5 kG, and most importantly, Hci from 1.1 kOe to 1.5 kOe. As a result, the room temperature energy product (BH)max has been increased by over 100% from 0.7 MGOe in Ce1.1Fe11Ti to 1.5 MGOe in Ce1.05Fe9.75Co1.25Ti. Microscopy analysis indicates that the addition of Co refines the grain size and promotes chemical homogeneity at the microscopic scale. As a result, the beneficial effect of Co on the microstructure contributes to the improved hard magnetic properties.« less

  12. 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

  13. 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.

  14. Pt3Ru6 Clusters Supported on gamma-Al2O3: Synthesis from Pt3Ru6(Cu)21(u3-H)(u-H)3, Structural Characterization, and Catalysis of Ethylene Hydrogenation and n-Butane Hydrogenolysis

    SciTech Connect (OSTI)

    Chotisuwan,S.; Wittayakun, J.; Gates, B.

    2006-01-01

    The supported clusters Pt-Ru/{gamma}-Al{sub 2}O{sub 3} were prepared by adsorption of the bimetallic precursor Pt{sub 3}Ru{sub 6}(Cu){sub 21}({mu}{sub 3}-H)({mu}-H){sub 3} from CH{sub 2}Cl{sub 2} solution onto {gamma}-Al{sub 2}O{sub 3} followed by decarbonylation in He at 300 C. The resultant supported clusters were characterized by infrared (IR) and extended X-ray absorption fine structure (EXAFS) spectroscopies and as catalysts for ethylene hydrogenation and n-butane hydrogenolysis. After adsorption, the {nu}{sub CO} peaks characterizing the precursor shifted to lower wavenumbers, and some of the hydroxyl bands of the support disappeared or changed, indicating that the CO ligands of the precursor interacted with support hydroxyl groups. The EXAFS results show that the metal core of the precursor remained essentially unchanged upon adsorption, but there were distortions of the metal core indicated by changes in the metal-metal distances. After decarbonylation of the supported clusters, the EXAFS data indicated that Pt and Ru atoms interacted with support oxygen atoms and that about half of the Pt-Ru bonds were maintained, with the composition of the metal frame remaining almost unchanged. The decarbonylated supported bimetallic clusters reported here are the first having essentially the same metal core composition as that of a precursor metal carbonyl, and they appear to be the best-defined supported bimetallic clusters. The material was found to be an active catalyst for ethylene hydrogenation and n-butane hydrogenolysis under conditions mild enough to prevent substantial cluster disruption.

  15. 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.

  16. Ultralow charge-transfer resistance with ultralow Pt loading for hydrogen evolution and oxidation using Ru@Pt core-shell nanocatalysts

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

    Wang, Jia X.; Zhang, Yu; Capuano, Christopher B.; Ayers, Katherine E.

    2015-07-15

    We evaluated the activities of well-defined Ru@Pt core-shell nanocatalysts for hydrogen evolution and oxidation reactions (HER-HOR) using hanging strips of gas diffusion electrode (GDE) in solution cells. With gas transport limitation alleviated by micro-porous channels in the GDEs, the charge transfer resistances (CTRs) at the hydrogen reversible potential were conveniently determined from linear fit of ohmic-loss-corrected polarization curves. In 1M HClO? at 23°C, a CTR as low as 0.04 ? cm² was obtained with only 20 ?g cm?² Pt and 11 ?g cm?² Ru using the carbon-supported Ru@Pt with 1:1 Ru:Pt atomic ratio. Derived from temperature-dependent CTRs, the activation barriermore »of the Ru@Pt catalyst for the HER-HOR in acids is 0.2 eV or 19 kJ mol?¹. Using the Ru@Pt catalyst with total metal loadings « less

  17. 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.

  18. , 2006, . 47, 5, c. 557--567 http://www.izdatgeo.ru PP C C CX X

    E-Print Network [OSTI]

    Cerveny, Vlastislav

    , 2006, . 47, 5, c. 557--567 http://www.izdatgeo.ru 550.834 PP C C CX X P P CP . p Republic pp c px px cx x, pcpcpxc p p p cp, c c c. c cc p P- S-, pcpcpxc px x - p. pp c p SH . px cx pp c , . . c p cpc, p c p pc - pc . c px cx c p pc p- c, cpc cc , p, c pcc cpx p

  19. $\\gamma$-ray linear polarization measurements and $(g_{9/2})^{-3}$ neutron alignment in $^{91}$Ru

    E-Print Network [OSTI]

    Zheng, Y; Clément, E; Dijon, A; Cederwall, B; Wadsworth, R; Bäck, T; Moradi, F Ghazi; Jaworski, G; Nyakó, B M; Nyberg, J; Palacz, M; Al-Azri, H; de Angelis, G; Atac, A; Akta?, Ö; Bhattacharyya, S; Brock, T; Davies, P J; Di Nitto, A; Dombradi, Zs; Gadea, A; Gal, J; Joshi, P; Juhasz, K; Julin, R; Jungclaus, A; Kalinka, G; Kownacki, J; La Rana, G; Lenzi, S M; Molnar, J; Moro, R; Napoli, D R; Singh, B S Nara; Persson, A; Recchia, F; Sandzelius, M; Scheurer, J -N; Sletten, G; Sohler, D; Söderström, P -A; Taylor, M J; Timar, J; Valiente-Dobon, J J; Vardaci, E

    2013-01-01

    Linear polarization measurements have been performed for $\\gamma$-rays in $^{91}$Ru produced with the $^{58}$Ni($^{36}$Ar, $2p1n$$\\gamma$)$^{91}$Ru reaction at a beam energy of 111 MeV. The EXOGAM Ge clover array has been used to measure the $\\gamma$-$\\gamma$ coincidences, $\\gamma$-ray linear polarization and $\\gamma$-ray angular distributions. The polarization sensitivity of the EXOGAM clover detectors acting as Compton polarimeters has been determined in the energy range 0.3$-$1.3 MeV. Several transitions have been observed for the first time. Measurements of linear polarization and angular distribution have led to the firm assignments of spin differences and parity of high-spin states in $^{91}$Ru. More specifically, calculations using a semi-empirical shell model were performed to understand the structures of the first and second (21/2$^{+}$) and (17/2$^{+}$) levels. The results are in good agreement with the experimental data, supporting the interpretation of the non yrast (21/2$^{+}$) and (17/2$^{+}$) s...

  20. 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.

  1. 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

  2. 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

  3. 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.

  4. 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...

  5. 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...

  6. 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...

  7. High temperature-induced phase transitions in Sr{sub 2}GdRuO{sub 6} complex perovskite

    SciTech Connect (OSTI)

    Triana, C.A.; Corredor, L.T.; Landinez Tellez, D.A.; Roa-Rojas, J.

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer Crystal structure, thermal expansion and phase transitions at high-temperature of Sr{sub 2}GdRuO{sub 6} perovskite has been investigated. Black-Right-Pointing-Pointer X-ray diffraction pattern at 298 K of Sr{sub 2}GdRuO{sub 6} corresponds to monoclinic perovskite-type structure with P2{sub 1}/n space group. Black-Right-Pointing-Pointer Evolution of X-ray diffraction patterns at high-temperature shows that the Sr{sub 2}GdRuO{sub 6} perovskite suffers two-phase transitions. Black-Right-Pointing-Pointer At 573 K the X-ray diffraction pattern of Sr{sub 2}GdRuO{sub 6} corresponds to monoclinic perovskite-type structure with I2/m space group. Black-Right-Pointing-Pointer At 1273 K the Sr{sub 2}GdRuO{sub 6} perovskite suffers a complete phase-transition from monoclinic I2/m (no. 12) to tetragonal I4/m (no. 87). -- Abstract: The crystal structure behavior of the Sr{sub 2}GdRuO{sub 6} complex perovskite at high-temperature has been investigated over a wide temperature range between 298 K {<=} T {<=} 1273 K. Measurements of X-ray diffraction at room-temperature and Rietveld analysis of the experimental patterns show that this compound crystallizes in a monoclinic perovskite-like structure, which belongs to the P2{sub 1}/n (no. 14) space group and 1:1 ordered arrangement of Ru{sup 5+} and Gd{sup 3+} cations over the six-coordinate M sites. Experimental lattice parameters were obtained to be a =5.8103(5) Angstrom-Sign , b =5.8234(1) Angstrom-Sign , c =8.2193(9) Angstrom-Sign , V = 278.11(2) Angstrom-Sign {sup 3} and angle {beta} = 90.310(5) Degree-Sign . The high-temperature analysis shows the occurrence of two-phase transitions on this material. First, at 573 K it adopts a monoclinic perovskite-type structure with I2/m (no. 12) space group with lattice parameters a = 5.8275(6) Angstrom-Sign , b = 5.8326(3) Angstrom-Sign , c = 8.2449(2) Angstrom-Sign , V = 280.31(3) Angstrom-Sign {sup 3} and angle {beta} = 90.251(3) Degree-Sign . Close to 1273 K it undergoes a complete phase-transition from monoclinic I2/m (no. 12) to tetragonal I4/m (no. 87), with lattice parameters a = 5.8726(1) Angstrom-Sign , c = 8.3051(4) Angstrom-Sign , V = 286.39(8) Angstrom-Sign {sup 3} and angle {beta} = 90.0 Degree-Sign . The high-temperature phase transition from monoclinic I2/m (no. 12) to tetragonal I4/m (no. 87) is characterized by strongly anisotropic displacements of the anions.

  8. 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

  9. 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.

  10. Intramolecular proton transfer boosts water oxidation catalyzed by a Ru complex

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

    Matheu, Roc; Ertem, Mehmed Z.; Benet-Buchholz, J.; Coronado, Eugenio; Batista, Victor S.; Sala, Xavier; Llobet, Antoni

    2015-07-30

    We introduce a new family of complexes with the general formula [Run(tda)(py)2]m+ (n = 2, m = 0, 1; n = 3, m = 1, 2+; n = 4, m = 2, 32+), with tda2– being [2,2':6',2"-terpyridine]-6,6"-dicarboxylate, including complex [RuIV(OH)(tda-?-N3O)(py)2]+, 4H+, which we find to be an impressive water oxidation catalyst, formed by hydroxo coordination to 32+ under basic conditions. The complexes are synthesized, isolated, and thoroughly characterized by analytical, spectroscopic (UV–vis, nuclear magnetic resonance, electron paramagnetic resonance), computational, and electrochemical techniques (cyclic voltammetry, differential pulse voltammetry, coulometry), including solid-state monocrystal X-ray diffraction analysis. In oxidation state IV, the Rumore »center is seven-coordinated and diamagnetic, whereas in oxidation state II, the complex has an unbonded dangling carboxylate and is six-coordinated while still diamagnetic. With oxidation state III, the coordination number is halfway between the coordination of oxidation states II and IV. Species generated in situ have also been characterized by spectroscopic, computational, and electrochemical techniques, together with the related species derived from a different degree of protonation and oxidation states. 4H+ can be generated potentiometrically, or voltammetrically, from 32+, and both coexist in solution. While complex 32+ is not catalytically active, the catalytic performance of complex 4H+ is characterized by the foot of the wave analysis, giving an impressive turnover frequency record of 8000 s–1 at pH 7.0 and 50,000 s–1 at pH 10.0. Density functional theory calculations provide a complete description of the water oxidation catalytic cycle of 4H+, manifesting the key functional role of the dangling carboxylate in lowering the activation free energies that lead to O–O bond formation.« less

  11. Isotopic tracer studies of Fischer-Tropsch Synthesis over Ru/TiO sub 2 catalysts

    SciTech Connect (OSTI)

    Krishna, K.R.

    1992-01-01

    Fischer-Tropsch synthesis is a process in which CO and H{sub 2} react to give predominantly liquid hydrocarbons. The reaction can be considered a special type of polymerization in which the monomer is produced in situ, and chain growth occurs by a sequence of independently repeated additions of the monomer to the growing chain. A investigation has been conducted to study the CO hydrogenation reaction in order to better understand catalyst deactivation and the elementary surface processes involved in chain growth. Isotopic tracers are used in conjunction with transient-response techniques in this study of Fischer-Tropsch synthesis over Ru/TiO{sub 2} catalysts. Experiments are conducted at a total pressure of 1 atmosphere, reaction temperatures of 453--498 K and D{sub 2}/CO (or H{sub 2}/CO) ratios of 2--5. Synthesis products are analyzed by gas chromatography or isotope-ratio gas chromatography-mass spectrometry. Rate constants for chain initiation, propagation and termination are evaluated under steady-state reaction conditions by using transients in isotopic composition. The activation energy for chain termination is much higher than that for propagation, accounting for the observed decrease in the chain growth parameter are also estimated. Coverages by reaction intermediates are also estimated. When small amounts of {sup 12}C-labelled ethylene are added to {sup 13}CO/H{sub 2} synthesis gas, ethylene acts as the sole chain initiator. Ethylene-derived carbon also accounts for 45% of the C{sub 1} monomer pool. 102 refs., 29 figs., 11 tabs.

  12. Isotopic tracer studies of Fischer-Tropsch Synthesis over Ru/TiO{sub 2} catalysts

    SciTech Connect (OSTI)

    Krishna, K.R.

    1992-01-01

    Fischer-Tropsch synthesis is a process in which CO and H{sub 2} react to give predominantly liquid hydrocarbons. The reaction can be considered a special type of polymerization in which the monomer is produced in situ, and chain growth occurs by a sequence of independently repeated additions of the monomer to the growing chain. A investigation has been conducted to study the CO hydrogenation reaction in order to better understand catalyst deactivation and the elementary surface processes involved in chain growth. Isotopic tracers are used in conjunction with transient-response techniques in this study of Fischer-Tropsch synthesis over Ru/TiO{sub 2} catalysts. Experiments are conducted at a total pressure of 1 atmosphere, reaction temperatures of 453--498 K and D{sub 2}/CO (or H{sub 2}/CO) ratios of 2--5. Synthesis products are analyzed by gas chromatography or isotope-ratio gas chromatography-mass spectrometry. Rate constants for chain initiation, propagation and termination are evaluated under steady-state reaction conditions by using transients in isotopic composition. The activation energy for chain termination is much higher than that for propagation, accounting for the observed decrease in the chain growth parameter are also estimated. Coverages by reaction intermediates are also estimated. When small amounts of {sup 12}C-labelled ethylene are added to {sup 13}CO/H{sub 2} synthesis gas, ethylene acts as the sole chain initiator. Ethylene-derived carbon also accounts for 45% of the C{sub 1} monomer pool. 102 refs., 29 figs., 11 tabs.

  13. XMM-NEWTON OBSERVATIONS OF THE DWARF NOVA RU Peg IN QUIESCENCE: PROBE OF THE BOUNDARY LAYER

    SciTech Connect (OSTI)

    Balman, Soelen [Department of Physics, Middle East Technical University, Ankara (Turkey); Godon, Patrick; Sion, Edward M. [Department of Astronomy and Astrophysics, Villanova University, Villanova, PA 19085 (United States); Ness, Jan-Uwe [XMM-Newton Science Operations Centre, European Space Agency (ESA/ESAC), E-28691 Villanueva de la Canada, Madrid (Spain); Schlegel, Eric [Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX 78249 (United States); Barrett, Paul E. [United States Naval Observatory, Washington, DC 20392 (United States); Szkody, Paula, E-mail: solen@astroa.physics.metu.edu.tr, E-mail: patrick.godon@villanova.edu, E-mail: edward.sion@villanova.edu, E-mail: juness@sciops.esa.int, E-mail: eric.schlegel@utsa.edu, E-mail: barrett.paul@usno.navy.mil, E-mail: szkody@astro.washington.edu [Astronomy Department, University of Seattle, Seattle, WA 98195 (United States)

    2011-11-10

    We present an analysis of X-ray and UV data obtained with the XMM-Newton Observatory of the long-period dwarf nova RU Peg. RU Peg contains a massive white dwarf (WD), possibly the hottest WD in a dwarf nova (DN), it has a low inclination, thus optimally exposing its X-ray emitting boundary layer (BL), and has an excellent trigonometric parallax distance. We modeled the X-ray data using XSPEC assuming a multi-temperature plasma emission model built from the MEKAL code (i.e., CEVMKL). We obtained a maximum temperature of 31.7 keV, based on the European Photon Imaging Camera MOS1, 2 and pn data, indicating that RU Peg has an X-ray spectrum harder than most DNe, except U Gem. This result is consistent with and indirectly confirms the large mass of the WD in RU Peg. The X-ray luminosity we computed corresponds to a BL luminosity for a mass accretion rate of 2 Multiplication-Sign 10{sup -11} M{sub sun} yr{sup -1} (assuming M{sub wd} = 1.3 M{sub sun}), in agreement with the expected quiescent accretion rate. The modeling of the O VIII emission line at 19 A as observed by the Reflection Grating Spectrometer implies a projected stellar rotational velocity v{sub rot}sin i = 695 km s{sup -1}, i.e., the line is emitted from material rotating at {approx}936-1245 km s{sup -1} (i {approx} 34 Degree-Sign -48 Degree-Sign) or about 1/6 of the Keplerian speed; this velocity is much larger than the rotation speed of the WD inferred from the Far Ultraviolet Spectroscopic Explorer spectrum. Cross-correletion analysis yielded an undelayed (time lag {approx} 0) component and a delayed component of 116 {+-} 17 s where the X-ray variations/fluctuations lagged the UV variations. This indicates that the UV fluctuations in the inner disk are propagated into the X-ray emitting region in about 116 s. The undelayed component may be related to irradiation effects.

  14. Spontaneous CO Release from RuII(CO)2–Protein Complexes in Aqueous Solution, Cells, and Mice

    E-Print Network [OSTI]

    Chaves-Ferreira, Miguel; Albuquerque, Inês S.; Matak-Vinkovic, Dijana; Coelho, Ana C.; Carvalho, Sandra M.; Saraiva, Lígia M.; Romão, Carlos C.; Bernardes, Gonçalo J. L.

    2014-12-04

    stream_source_info Chaves_Ferreira_et_al-2015-Angewandte_Chemie_International_Edition.pdf.txt stream_content_type text/plain stream_size 21359 Content-Encoding UTF-8 stream_name Chaves_Ferreira_et_al-2015-Angewandte_Chemie... denaturing conditions. c) ESI-MS analysis of CO release from HEWL–RuII(CO)2 at 0, 2, and 4 h in aqueous buffered solution (PBS pH 7.4). Angewandte Chemie 1173Angew. Chem. Int. Ed. 2015, 54, 1172 –1175 ? 2015 The Authors. Published by Wiley-VCH Verlag Gmb...

  15. Comparison of Two Preparation Methods on Catalytic Activity and Selectivity of Ru-Mo/HZSM5 for Methane Dehydroaromatization

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

    Petkovic, Lucia M.; Ginosar, Daniel M.

    2014-01-01

    Catalytic performance of Mo/HZSM5 and Ru-Mo/HZSM5 catalysts prepared by vaporization-deposition of molybdenum trioxide and impregnation with ammonium heptamolybdate was analyzed in terms of catalyst activity and selectivity, nitrogen physisorption analyses, temperature-programmed oxidation of carbonaceous residues, and temperature-programmed reduction. Vaporization-deposition rendered the catalyst more selective to ethylene and coke than the catalyst prepared by impregnation. This result was assigned to lower interaction of molybdenum carbide with the zeolite acidic sites.

  16. Half-life of the electron-capture decay of (97)Ru: Precision measurement shows no temperature dependence 

    E-Print Network [OSTI]

    Goodwin, J. R.; Golovko, V. V.; Iacob, V. E.; Hardy, John C.

    2009-01-01

    as having a 1.2(2)% shorter half-life at 12 K [5]; and 7Be, which decays by pure electron capture, apparently had a half-life longer by 0.9(2)% at 12 K in palladium and by 0.7(2)% in indium [6]. The authors of these reports also proposed a theoretical... for any allowed transition from 97Ru is 892 keV, the nucleus must decay by pure electron capture. Three years ago, Wang et al. [6] reported half-life measurements of another pure electron-capture emitter, 7Be, situated in both palladium and indium...

  17. Project RU LlSON COPY ON-SITE RADIOLOGICAL PROGRAMS DURING REENTRY DISILLING THROUGH PRODUCTION TESTING

    Office of Legacy Management (LM)

    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 NaturalDukeWakefield Municipal Gas &SCE-SessionsSouthReport for the Weldon Spring,7=cr5rnP 7694Performed Under OnlyRU

  18. Exotic magnetism on the quasi-FCC lattices of the d3 double perovskites La2NaB'O6 (B' = Ru, Os)

    SciTech Connect (OSTI)

    Aczel, Adam A; Baker, Peter J.; Bugaris, Dan; Yeon, Jeongho; Zur Loye, Hans-Conrad; Guidi, T.; Adroja, D. T.

    2014-01-01

    We find evidence for long-range and short-range ($\\zeta$~$=$~70~\\AA~at 4~K) incommensurate magnetic order on the quasi-face-centered-cubic (FCC) lattices of the monoclinic double perovskites La$_2$NaRuO$_6$ and La$_2$NaOsO$_6$ respectively. Incommensurate magnetic order on the FCC lattice has not been predicted by mean field theory, but may arise via a delicate balance of inequivalent nearest neighbour and next nearest neighbour exchange interactions. In the Ru system with long-range order, inelastic neutron scattering also reveals a spin gap $\\Delta$~$\\sim$~2.75~meV. Magnetic anisotropy is generally minimized in the more familiar octahedrally-coordinated $3d^3$ systems, so the large gap observed for La$_2$NaRuO$_6$ may result from the significantly enhanced value of spin-orbit coupling in this $4d^3$ material.

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

    SciTech Connect (OSTI)

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

    1997-09-01

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

  20. Adsorption of water on O(2x2)/Ru(0001): thermal stability and inhibition of dissociation by H2O-O bonding

    SciTech Connect (OSTI)

    Mugarza, Aitor; Shimizu, Tomoko; Cabrera-Sanfelix, Pepa; Sanchez-Portal, Daniel; Arnau, Andres; Salmeron, Miquel

    2008-08-01

    The effect of preadsorbed oxygen on the subsequent adsorption and reactions of water on Ru(0001) has been studied using low temperature scanning tunneling microscopy and DFT calculations. Experiments were carried out for O coverages close to 0.25 ML. It was found that no dissociation of water takes place up to the desorption temperature of {approx}180-230 K. DFT calculations show that intact water on O(2x2)/Ru(0001) is {approx} 0.49 eV more stable than the dissociation products, H and OH, at their preferred fcc and top adsorption sites.

  1. 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

  2. Microsoft Word - Nitrogenase2015 bh

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

    Haber-Bosch-process accounts for the other half to provide nitrogen-fertilizer for crop growth. Therefore, the Haber-Bosch process indirectly feeds half of the world's...

  3. 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

  4. 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

  5. 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...

  6. 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...

  7. 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

  8. Chemical control of hole-doped superconductivity and magnetism in Gd2-xCexRuSr2Cu2O10-d 

    E-Print Network [OSTI]

    McLaughlin, A C; Attfield, J. Paul; Asaf, U; Felner, I

    2003-01-01

    Three Gd2-xCexRuSr2Cu2O10-d samples (x=0.5, as prepared and after high pressure oxygenation and x =0.7) have been investigated by synchrotron powder x-ray diffraction and magnetization measurements. Precise coordinates ...

  9. Low-temperature growth and orientational control in RuO{sub 2} thin films by metal-organic chemical vapor deposition

    SciTech Connect (OSTI)

    Bai, G.R.; Wang, A.; Foster, C.M.; Vetrone, J.; Patel, J.; Wu, X.

    1996-08-01

    For growth temperatures in the range of 275 C to 425 C, highly conductive RuO{sub 2} thin films with either (110)- or (101)-textured orientations have been grown by metal-organic chemical vapor deposition (MOCVD) on both SiO{sub 2}/Si(001) and Pt/Ti/SiO{sub 2}/Si(001) substrates. Both the growth temperature and growth rate were used to control the type and degree of orientational texture of the RuO{sub 2} films. In the upper part of this growth temperature range ({approximately} 350 C) and at a low growth rate (< 30 {angstrom}/min.), the RuO{sub 2} films favored a (110)-textured. In contrast, at the lower part of this growth temperature range ({approximately} 300 C) and at a high growth rate (> 30 {angstrom}/min.), the RuO{sub 2} films favored a (101)-textured. In contrast, a higher growth temperatures (> 425 C) always produced randomly-oriented polycrystalline films. For either of these low-temperature growth processes, the films produced were crack-free, well-adhered to the substrates, and had smooth, specular surfaces. Atomic force microscopy showed that the films had a dense microstructure with an average grain size of 50--80 nm and a rms. surface roughness of {approximately} 3--10 nm. Four-probe electrical transport measurements showed that the films were highly conductive with resistivities of 34--40 {micro}{Omega}-cm ({at} 25 C).

  10. Giant dielectric response in Pb,,Zr,Ti...O3Pb2Ru2O6.5 all-ceramic percolative composite

    E-Print Network [OSTI]

    Bobnar, Vid

    Giant dielectric response in Pb,,Zr,Ti...O3­Pb2Ru2O6.5 all-ceramic percolative composite Vid Bobnar response of a composite comprising a conductive filler embedded in a dielectric matrix--the effective­9 and inorganic composites comprising metal particles dis- persed in a dielectric matrix10­14 have been developed

  11. First Measurement of the $^{96}$Ru(p,$?$)$^{97}$Rh Cross Section for the p-Process with a Storage Ring

    E-Print Network [OSTI]

    Bo Mei; Thomas Aumann; Shawn Bishop; Klaus Blaum; Konstanze Boretzky; Fritz Bosch; Carsten Brandau; Harald Bräuning; Thomas Davinson; Iris Dillmann; Christina Dimopoulou; Olga Ershova; Zsolt Fülöp; Hans Geissel; Jan Glorius; György Gyürky; Michael Heil; Franz Käppeler; Aleksandra Kelic-Heil; Christophor Kozhuharov; Christoph Langer; Tudi Le Bleis; Yuri Litvinov; Gavin Lotay; Justyna Marganiec; Gottfried Münzenberg; Fritz Nolden; Nikolaos Petridis; Ralf Plag; Ulrich Popp; Ganna Rastrepina; René Reifarth; Björn Riese; Catherine Rigollet; Christoph Scheidenberger; Haik Simon; Kerstin Sonnabend; Markus Steck; Thomas Stöhlke; Tamás Szücs; Klaus Sümmerer; Günter Weber; Helmut Weick; Danyal Winters; Natalya Winters; Philip Woods; Qiping Zhong

    2015-07-10

    This work presents a direct measurement of the $^{96}$Ru($p, \\gamma$)$^{97}$Rh cross section via a novel technique using a storage ring, which opens opportunities for reaction measurements on unstable nuclei. A proof-of-principle experiment was performed at the storage ring ESR at GSI in Darmstadt, where circulating $^{96}$Ru ions interacted repeatedly with a hydrogen target. The $^{96}$Ru($p, \\gamma$)$^{97}$Rh cross section between 9 and 11 MeV has been determined using two independent normalization methods. As key ingredients in Hauser-Feshbach calculations, the $\\gamma$-ray strength function as well as the level density model can be pinned down with the measured ($p, \\gamma$) cross section. Furthermore, the proton optical potential can be optimized after the uncertainties from the $\\gamma$-ray strength function and the level density have been removed. As a result, a constrained $^{96}$Ru($p, \\gamma$)$^{97}$Rh reaction rate over a wide temperature range is recommended for $p$-process network calculations.

  12. First Measurement of the $^{96}$Ru(p,$\\gamma$)$^{97}$Rh Cross Section for the p-Process with a Storage Ring

    E-Print Network [OSTI]

    Mei, Bo; Bishop, Shawn; Blaum, Klaus; Boretzky, Konstanze; Bosch, Fritz; Brandau, Carsten; Bräuning, Harald; Davinson, Thomas; Dillmann, Iris; Dimopoulou, Christina; Ershova, Olga; Fülöp, Zsolt; Geissel, Hans; Glorius, Jan; Gyürky, György; Heil, Michael; Käppeler, Franz; Kelic-Heil, Aleksandra; Kozhuharov, Christophor; Langer, Christoph; Bleis, Tudi Le; Litvinov, Yuri; Lotay, Gavin; Marganiec, Justyna; Münzenberg, Gottfried; Nolden, Fritz; Petridis, Nikolaos; Plag, Ralf; Popp, Ulrich; Rastrepina, Ganna; Reifarth, René; Riese, Björn; Rigollet, Catherine; Scheidenberger, Christoph; Simon, Haik; Sonnabend, Kerstin; Steck, Markus; Stöhlke, Thomas; Szücs, Tamás; Sümmerer, Klaus; Weber, Günter; Weick, Helmut; Winters, Danyal; Winters, Natalya; Woods, Philip; Zhong, Qiping

    2015-01-01

    This work presents a direct measurement of the $^{96}$Ru($p, \\gamma$)$^{97}$Rh cross section via a novel technique using a storage ring, which opens opportunities for reaction measurements on unstable nuclei. A proof-of-principle experiment was performed at the storage ring ESR at GSI in Darmstadt, where circulating $^{96}$Ru ions interacted repeatedly with a hydrogen target. The $^{96}$Ru($p, \\gamma$)$^{97}$Rh cross section between 9 and 11 MeV has been determined using two independent normalization methods. As key ingredients in Hauser-Feshbach calculations, the $\\gamma$-ray strength function as well as the level density model can be pinned down with the measured ($p, \\gamma$) cross section. Furthermore, the proton optical potential can be optimized after the uncertainties from the $\\gamma$-ray strength function and the level density have been removed. As a result, a constrained $^{96}$Ru($p, \\gamma$)$^{97}$Rh reaction rate over a wide temperature range is recommended for $p$-process network calculations.

  13. Excited State Dynamics of Two New Ru(II) Cyclometallated Dyes: Relation to Cells for Solar Energy Conversion and Comparison to

    E-Print Network [OSTI]

    Turro, Claudia

    Excited State Dynamics of Two New Ru(II) Cyclometallated Dyes: Relation to Cells for Solar Energy, are reported. Related complexes have been used as efficient dyes in dye- sensitized solar cells (DSSCs of ruthenium dyes used in DSSCs to lower energies, it is evident from this work, that for cyclometallated phpy

  14. Anisotropic hot deformed magnets prepared from Zn-coated MRE-Fe-B ribbon powder (MRE?=?Nd?+?Y?+?Dy)

    SciTech Connect (OSTI)

    Tang, W; Zhou, L; Sun, K W; Dennis, K W; Kramer, M J; Anderson, I E; McCallum, R W

    2014-05-07

    Milled melt-spun ribbon flake of MRE-Fe-B coated with Zn coating using a vapor transport technique was found to have significant increase in coercivity without degrading the magnetization when the Zn thickness and heat treatment were optimized. Magnetic measurements show that 0.5–1?wt.?% Zn coating increases the coercivity about 1?kOe over the initial ribbon powder. After vacuum hot deformation (VHD), the VHD magnet with Zn coating of 0.5?wt.?% results in a nearly 3?kOe higher coercivity than an un-coated alloy magnet. An optimized VHD magnet with 0.5?wt.?% Zn coating obtains a coercivity of 11.2?kOe and (BH)max of 23.0 MGOe, respectively. SEM and TEM microstructures analysis demonstrates that the Zn coating on the surface of ribbon powder has diffused along the intergranular boundaries after the ribbon powder was annealed at 750?°C for 30?min or was hot deformed at 700–750?°C.

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Observation of Transverse Bose-Einstein Condensation via Hanbury BrownTwiss Correlations Wu RuGway, A. G. Manning, S. S. Hodgman, R. G. Dall, and A. G. Truscott

    E-Print Network [OSTI]

    Kheruntsyan, Karen

    Observation of Transverse Bose-Einstein Condensation via Hanbury Brown­Twiss Correlations Wu Ru a three-dimensional thermal gas to a gas undergoing transverse condensation by probing Hanbury Brown­Twiss

  2. 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....

  3. 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.

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. Frustration by competing interactions in the highly-distorted double perovskites La2NaB'O6 (B' = Ru, Os)

    SciTech Connect (OSTI)

    Aczel, Adam A [ORNL; Bugaris, Dan [University of South Carolina; Li, Ling [University of Tennessee, Knoxville (UTK); Yan, Jiaqiang [ORNL; Dela Cruz, Clarina R [ORNL; Zur Loye, Hans-Conrad [University of South Carolina; Nagler, Stephen E [ORNL

    2013-01-01

    The usual classical behaviour of S = 3/2, B-site ordered double perovskites generally results in simple, commensurate magnetic ground states. In contrast, heat capacity and neutron powder diffraction measurements for the S = 3/2 systems La2NaB'O6 (B = Ru, Os) reveal an incommensurate magnetic ground state for La2NaRuO6 and a drastically suppressed ordered moment for La2NaOsO6. This behaviour is attributed to the large monoclinic structural distortions of these double perovskites. The distortions have the effect of weakening the nearest neighbour superexchange interactions, presumably to an energy scale that is comparable to the next nearest neighbour superexchange. The exotic ground states in these materials can then arise from a competition between these two types of antiferromagnetic interactions, providing a novel mechanism for achieving frustration in the double perovskite family.

  9. Synthesis and microstructural TEM investigation of CaCu{sub 3}Ru{sub 4}O{sub 12} ceramic and thin film

    SciTech Connect (OSTI)

    Brize, Virginie [Universite Francois Rabelais, LEMA, UMR 6157 CNRS-CEA, Parc de Grandmont, 37200 Tours (France); STMicroelectronics, 16 rue P and M Curie, 37001 Tours (France); Autret-Lambert, Cecile, E-mail: cecile.autret-lambert@univ-tours.fr [Universite Francois Rabelais, LEMA, UMR 6157 CNRS-CEA, Parc de Grandmont, 37200 Tours (France); Wolfman, Jerome; Gervais, Monique; Gervais, Francois [Universite Francois Rabelais, LEMA, UMR 6157 CNRS-CEA, Parc de Grandmont, 37200 Tours (France)

    2011-10-15

    CaCu{sub 3}Ru{sub 4}O{sub 12} (CCRO) is a conductive oxide having the same structure as CaCu{sub 3}Ti{sub 4}O{sub 12} (CCTO) and close lattice parameters. The later compound is strongly considered for high density parallel plates capacitors application due to its so-called colossal dielectric constant. The need for an electrode inducing CCTO epitaxial growth with a clean and sharp interface is therefore necessary, and CCRO is a good potential candidate. In this paper, the synthesis of monophasic CCRO ceramic is reported, as well as pulsed laser deposition of CCRO thin film onto (001) NdCaAlO{sub 4} substrate. Structural and physical properties of bulk CCRO were studied by transmission electron microscopy and electron spin resonance. CCRO films and ceramic exhibited a metallic behavior down to low temperature. CCRO films were (001) oriented and promoted a CCTO film growth with the same orientation. - Graphical Abstract: Structure of CaCu{sub 3}Ru{sub 4}O{sub 12} showing the RuO{sub 6} octahedra and the square planar environment for Cu{sup 2+}. Highlights: > In this study, we investigate the structural properties and microstructure of ceramics CaCu{sub 3}Ru{sub 4}O{sub 12}. > We study the conduction properties of polycrystalline material. > Then we synthesize the conductive thin film which is deposited on a high K material with the same structure (CaCu{sub 3}Ti{sub 4}O{sub 12}).

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Tuning the metal-insulator crossover and magnetism in SrRuO3 by ionic gating

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

    Yi, Hee Taek; Gao, Bin; Xie, Wei; Cheong, Sang -Wook; Podzorov, Vitaly

    2014-10-13

    Reversible control of charge transport and magnetic properties without degradation is a key for device applications of transition metal oxides. Chemical doping during the growth of transition metal oxides can result in large changes in physical properties, but in most of the cases irreversibility is an inevitable constraint. We report a reversible control of charge transport, metal-insulator crossover and magnetism in field-effect devices based on ionically gated archetypal oxide system - SrRuO3. In these thin-film devices, the metal-insulator crossover temperature and the onset of magnetoresistance can be continuously and reversibly tuned in the range 90–250 K and 70–100 K, respectively,more »by application of a small gate voltage. We infer that a reversible diffusion of oxygen ions in the oxide lattice dominates the response of these materials to the gate electric field. These findings provide critical insights into both the understanding of ionically gated oxides and the development of novel applications.« less

  17. Tuning the metal-insulator crossover and magnetism in SrRuO3 by ionic gating

    SciTech Connect (OSTI)

    Yi, Hee Taek; Gao, Bin; Xie, Wei; Cheong, Sang -Wook; Podzorov, Vitaly

    2014-10-13

    Reversible control of charge transport and magnetic properties without degradation is a key for device applications of transition metal oxides. Chemical doping during the growth of transition metal oxides can result in large changes in physical properties, but in most of the cases irreversibility is an inevitable constraint. We report a reversible control of charge transport, metal-insulator crossover and magnetism in field-effect devices based on ionically gated archetypal oxide system - SrRuO3. In these thin-film devices, the metal-insulator crossover temperature and the onset of magnetoresistance can be continuously and reversibly tuned in the range 90–250 K and 70–100 K, respectively, by application of a small gate voltage. We infer that a reversible diffusion of oxygen ions in the oxide lattice dominates the response of these materials to the gate electric field. These findings provide critical insights into both the understanding of ionically gated oxides and the development of novel applications.

  18. 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.

  19. 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.

  20. 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.

  1. 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).

  2. [?/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].

  3. 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

  4. 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

  5. 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

  6. 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.

  7. 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...

  8. 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,...

  9. 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...

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. Ternary rare-earth ruthenium and iridium germanides RE{sub 3}M{sub 2}Ge{sub 3} (RE=Y, Gd–Tm, Lu; M=Ru, Ir)

    SciTech Connect (OSTI)

    Oliynyk, Anton O.; Stoyko, Stanislav S.; Mar, Arthur, E-mail: arthur.mar@ualberta.ca

    2013-06-15

    Through arc-melting reactions of the elements and annealing at 800 °C, the ternary rare-earth germanides RE{sub 3}Ru{sub 2}Ge{sub 3} and RE{sub 3}Ir{sub 2}Ge{sub 3} have been prepared for most of the smaller RE components (RE=Y, Gd–Tm, Lu). In the iridium-containing reactions, the new phases RE{sub 2}IrGe{sub 2} were also generally formed as by-products. Powder X-ray diffraction revealed orthorhombic Hf{sub 3}Ni{sub 2}Si{sub 3}-type structures (space group Cmcm, Z=4) for RE{sub 3}M{sub 2}Ge{sub 3} (M=Ru, Ir) and monoclinic Sc{sub 2}CoSi{sub 2}-type structures (space group C2/m, Z=4) for RE{sub 2}IrGe{sub 2}. Full crystal structures were determined by single-crystal X-ray diffraction for all members of RE{sub 3}Ru{sub 2}Ge{sub 3} (a=4.2477(6) Å, b=10.7672(16) Å, c=13.894(2) Å for RE=Y; a=4.2610(3)–4.2045(8) Å, b=10.9103(8)–10.561(2) Å, c=14.0263(10)–13.639(3) Å in the progression of RE from Gd to Lu) and for Tb{sub 3}Ir{sub 2}Ge{sub 3} (a=4.2937(3) Å, b=10.4868(7) Å, c=14.2373(10) Å). Both structures can be described in terms of CrB- and ThCr{sub 2}Si{sub 2}-type slabs built from Ge-centred trigonal prisms. However, band structure calculations on Y{sub 3}Ru{sub 2}Ge{sub 3} support an alternative description for RE{sub 3}M{sub 2}Ge{sub 3} based on [M{sub 2}Ge{sub 3}] layers built from linked MGe{sub 4} tetrahedra, which emphasizes the strong M–Ge covalent bonds present. The temperature dependence of the electrical resistivity of RE{sub 3}Ru{sub 2}Ge{sub 3} generally indicates metallic behaviour but with low-temperature transitions visible for some members (RE=Gd, Tb, Dy) that are probably associated with magnetic ordering of the RE atoms. Anomalously, Y{sub 3}Ru{sub 2}Ge{sub 3} exhibits semiconductor-like behaviour of uncertain origin. Magnetic measurements on Dy{sub 3}Ru{sub 2}Ge{sub 3} reveal antiferromagnetic ordering at 3 K and several unusual field-dependent transitions suggestive of complex spin reorientation processes. - Graphical abstract: RE{sub 3}M{sub 2}Ge{sub 3} (M=Ru, Ir) adopts the Hf{sub 3}Ni{sub 2}Si{sub 3}-type structure containing slabs built up from Ge-centred trigonal prisms. - Highlights: • Crystal structures of RE{sub 3}Ru{sub 2}Ge{sub 3} (RE=Y, Gd–Tm, Lu) and Tb{sub 3}Ir{sub 2}Ge{sub 3} were determined. • Strong M–Ge covalent bonds were confirmed by band structure calculations. • Most RE{sub 3}Ru{sub 2}Ge{sub 3} members except Y{sub 3}Ru{sub 2}Ge{sub 3} exhibit metallic behaviour. • Dy{sub 3}Ru{sub 2}Ge{sub 3} displays unusual field-dependent magnetic transitions.

  15. 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

  16. 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

  17. 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

  18. 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

  19. Photovoltaic properties of Aurivillius phase Bi{sub 5}FeTi{sub 3}O{sub 15} thin films grown by pulsed laser deposition

    SciTech Connect (OSTI)

    Kooriyattil, Sudheendran; Katiyar, Rajesh K.; Pavunny, Shojan P. E-mail: shojanpp@gmail.com; Morell, Gerardo; Katiyar, Ram S. E-mail: shojanpp@gmail.com

    2014-08-18

    We report a remarkable photovoltaic effect in pulsed laser deposited multiferroic aurivillius phase Bi{sub 5}FeTi{sub 3}O{sub 15} (BFTO) thin films sandwiched between ZnO:Al transparent conductive oxide top electrode and SrRuO{sub 3} bottom electrode fabricated on amorphous fused silica substrates. The structural and micro structural properties of these films were analysed by X-ray diffraction and atomic force microscopy techniques. The films were showing a photo sensitive ferroelectric behaviour with a notable apparent polarization in the range of 10–15??C/cm{sup 2}. These films also exhibited a switchable photo-response and this parameter was observed to be sensitive to polarisation field and the polarization direction. The device shows a large ON/OFF photo current ratio with an open circuit voltage of 0.14?V. The photo response at zero bias of this BFTO based heterostructures showed rapid increase to a saturation value of 6??A at zero bias.

  20. 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

  1. Systematic kinetics of high-nuclearity metal carbonyl clusters. Exceptional behavior of Ru[sub 5]C(CO)[sub 15] with P-donor nucleophiles

    SciTech Connect (OSTI)

    Farrar, D.H.; Poee, A.J.; Zheng, Y. (Univ. of Toronto, Ontario (Canada))

    1994-07-13

    The kinetics of reactions of the high-nuclearity carbonyl cluster (HNCC), Ru[sub 5]C(CO)[sub 15], with 21 P-donor nucleophiles, L, to form Ru[sub 5]C(CO)[sub 14]L have been studied. The nucleophiles were chosen such that their electronic (pK[prime][sub a] = [minus]2.79 to 12.20) and steric (Tolman cone angles, [theta] = 101-182[degree]) properties are systematically varied. With 10 smaller nucleophiles ([theta] [le] 133[degree]) the reactions occur via two well-separated steps: adduct formation and CO-dissociation from the adducts to form the monosubstituted products. The structures of the adducts formed are shown spectroscopically to be closely related to other reported and structurally characterized elsewhere. The rate equations for the two steps are effectively k[sub obs] = k[sub +L][L] and [kappa][sub obs] = [kappa]-[sub CO], respectively. With 11 larger nucleophiles ([theta] [ge] 136[degree]) the reaction is a quite different, second-order one-step, process with no spectral evidence for adduct formation being observed. Quantitative analysis of the dependence of the various rate constants on the electronic and steric properties of the nucleophiles or ligands involved shows that adduct formation of this HNCC with the group of smaller nucleophiles is much more facile than any comparable nucleophile-dependent reactions of other metal carbonyls. 37 refs., 5 figs., 7 tabs.

  2. Ultra-high-performance core–shell structured Ru@Pt/C catalyst prepared by a facile pulse electrochemical deposition method

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

    Chen, Dan; Li, Yuexia; Liao, Shijun; Su, Dong; Song, Huiyu; Li, Yingwei; Yang, Lijun; Li, Can

    2015-08-03

    Core–shell structured catalysts, made by placing either a monolayer or a thin layer of a noble metal on relatively cheap core-metal nanoparticles, are fascinating and promising fuel cell catalysts due to their high utilization of noble metals. Here, we report our development of a core–shell structured catalyst, Ru@Pt/C, generated by a novel and facile pulse electrochemical deposition (PED) approach. We demonstrate that compared with a commercial Pt/C catalyst, this novel catalyst achieves over four times higher mass activity towards the anodic oxidation of methanol, and 3.6 times higher mass activity towards the cathodic reduction of oxygen. Importantly, we find thatmore »the intrinsic activity of Pt in this Ru@Pt/C catalyst is doubled due to the formation of the core–shell structure. The catalyst also shows superior stability: even after 2000 scans, it still retains up to 90% of the peak current. As a result, our findings demonstrate that this novel PED approach is a promising method for preparing high-performance core–shell catalysts for fuel cell applications.« less

  3. Structural characterisation of BaTiO{sub 3} thin films deposited on SrRuO{sub 3}/YSZ buffered silicon substrates and silicon microcantilevers

    SciTech Connect (OSTI)

    Colder, H.; Jorel, C. Méchin, L.; Domengès, B.; Marie, P.; Boisserie, M.; Guillon, S.; Nicu, L.; Galdi, A.

    2014-02-07

    We report on the progress towards an all epitaxial oxide layer technology on silicon substrates for epitaxial piezoelectric microelectromechanical systems. (101)-oriented epitaxial tetragonal BaTiO{sub 3} (BTO) thin films were deposited at two different oxygen pressures, 5.10{sup ?2} mbar and 5.10{sup ?3} mbar, on SrRuO{sub 3}/Yttria-stabilized zirconia (YSZ) buffered silicon substrates by pulsed laser deposition. The YSZ layer full (001) orientation allowed the further growth of a fully (110)-oriented conductive SrRuO{sub 3} electrode as shown by X-ray diffraction. The tetragonal structure of the BTO films, which is a prerequisite for the piezoelectric effect, was identified by Raman spectroscopy. In the BTO film deposited at 5.10{sup ?2} mbar strain was mostly localized inside the BTO grains whereas at 5.10{sup ?3} mbar, it was localized at the grain boundaries. The BTO/SRO/YSZ layers were finally deposited on Si microcantilevers at an O{sub 2} pressure of 5.10{sup ?3} mbar. The strain level was low enough to evaluate the BTO Young modulus. Transmission electron microscopy (TEM) was used to investigate the epitaxial quality of the layers and their epitaxial relationship on plain silicon wafers as well as on released microcantilevers, thanks to Focused-Ion-Beam TEM lamella preparation.

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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.

  11. Dpon ru Paean 5

    E-Print Network [OSTI]

    Gcod pa don 'grub

    ." This song is sung to celebrate a lama's arrival or for a house warming party. ?????????????????????????????????????????????????????????????????????? ????????????????????????????????????????????????? ??????????????????????????????????????????? ?????????????... and context (include reference to any related documentation, such as photographs) Location of Reb gong County http://commons.wikimedia.org/wiki/ File:Location_of_Tongren_within_Qinghai_(China).png ...

  12. Dpon ru Paean 4

    E-Print Network [OSTI]

    Gcod pa don 'grub

    ." This song is sung to celebrate a lama's arrival or for a house warming party. ?????????????????????????????????????????????????????????????????????? ????????????????????????????????????????????????? ??????????????????????????????????????????? ?????????????... and context (include reference to any related documentation, such as photographs) Location of Reb gong County http://commons.wikimedia.org/wiki/ File:Location_of_Tongren_within_Qinghai_(China).png ...

  13. Doc.~:Ru.

    Office of Legacy Management (LM)

    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 NaturalDukeWakefield Municipal Gas &SCE-SessionsSouth DakotaRobbins and Myers CoMadison -T: Designation of Sites' :.' ,

  14. Ru!fsa!!

    Office of Legacy Management (LM)

    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 NaturalDukeWakefield Municipal Gas &SCE-SessionsSouthReport for the Weldon Spring,7=cr5rnPandAlba Craftaehsed

  15. 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.

  16. Complex electronic states in double-layered ruthenates (Sr1-xCax)3Ru2O7 Zhe Qu,1 Jin Peng,1 Tijiang Liu,1 David Fobes,1 Leonard Spinu,2 and Zhiqiang Mao1,*

    E-Print Network [OSTI]

    Spinu, Leonard

    . In this report we elucidate the electronic properties for these magnetic states, and show that the electronic ferromagnetic FM state with an extremely large Wilson ratio Rw 0.08 x 0.4 . Rw is 10 for Sr3Ru2O7 Ref. 13

  17. Ru-induced loss of long-range magnetic order in a-Fe90 xRuxZr10 Physics Department, McGill University, 3600 University Street, Montreal, Quebec H3A 2T8, Canada

    E-Print Network [OSTI]

    Ryan, Dominic

    , The University of New South Wales, Sydney, NSW 2052, Australia Zin Tun AECL, Chalk River Laboratories, Chalk the DUALSPEC triple-axis spectrometer at AECL, Chalk River. Initial polarizations of 95% at 0.237 nm were River, Ontario K0J 1J0, Canada Mo¨sbauer spectroscopy, magnetization, susceptibility, and neutron

  18. 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

  19. 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.

  20. 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...

  1. 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,...

  2. 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.

  3. 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 ...

  4. 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...

  5. 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...

  6. 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).

  7. 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.

  8. Local magnetism in the molecule-based metamagnet [Ru2(O2CMe)4]3[Cr(CN)6] probed with implanted muons

    SciTech Connect (OSTI)

    Lancaster, T.; Pratt, F. L.; Blundell, S. J.; Steele, Andrew J.; Baker, Peter J.; Wright, Jack D.; Fishman, Randy Scott; Miller, Joel S.

    2011-01-01

    We present a muon-spin relaxation study of local magnetism in the molecule-based metamagnet [Ru2(O2CMe)4]3[Cr(CN)6]. We observe magnetic order with TN = 33 K, although above 25 K the sublattice spins become less rigid and a degree of static magnetic disorder is observed. The comparison of measurements in applied magnetic field with simulations allows us to understand the origin of the muon response across the metamagnetic transition and to map out the phase diagram of the material. Applied hydrostatic pressures of up to 6 kbar lead to an increase in the local magnetic field along with a complex change in the internal magnetic field distribution.

  9. Dopant-Induced Nanoscale Electronic Inhomogeneities in Ca2-xSrxRuO4

    SciTech Connect (OSTI)

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

    2006-01-01

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

  10. 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.

  11. 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...

  12. 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).

  13. Microsoft Word - Multiscale_Speciation bh

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

    initial step in U paragenesis is oxidation so that subsequent alteration phases are uranyl compounds, the absence of U(VI) may be because of the high temperature and...

  14. Microsoft Word - Cohen-Goniometer bh

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

    on XPP until the MFX station is fully operational in 2016. Primary Citation A. E. Cohen, S. M. Soltis, A. Gonzlez, L. Aguila, R. Alonso-Mori, C. O. Barnes, E. L. Baxter, W....

  15. Microsoft Word - MappingMetals bh

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

    Fluid catalytic cracking (FCC) is the refining process for converting large andor heavy molecules of oil feedstock into smaller and lighter hydrocarbons, such as gasoline....

  16. Microsoft Word - SupramolecularProtAssy bh

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

    (PDB 3IQ6). 1 One of the Zn binding motifs ensured the stable self-assembly of the tetramer, whereas the other motif anchored coordinatively unsaturated Zn sites for catalysis....

  17. Microsoft Word - Brunger-SNARE-2015 bh

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

    Synaptic Neurotransmitter Release Scientists at Stanford University School of Medicine have determined the 3-D structure of a complex of synaptic proteins that controls the...

  18. Microsoft Word - Brunger-SNARE-2015 bh

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformationJessework uses concrete and realisticQuarterStochastic Mean-Field

  19. Microsoft Word - Cohen-Goniometer bh

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformationJessework uses concrete andGoniometer-based Femtosecond Macromolecular

  20. Microsoft Word - MediaTechnology bh

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformationJessework uses concrete7 Assessment of theUMBRELLA PROPRIETARY8DynamicsDOE

  1. Microsoft Word - Multiscale_Speciation bh

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformationJessework uses concrete7 Assessment of theUMBRELLAProject Proposal Form43

  2. Microsoft Word - P450-I bh

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformationJessework uses concrete7 Assessment ofLana Cox (803) TO: Faculty,ARM-0401August

  3. Microsoft Word - Translocator_protein bh

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformationJessework uses concrete7 Assessment ofLana Cox (803)7-3373 Rev.Bilateral

  4. 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.

  5. 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...

  6. 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.

  7. 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.

  8. 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.

  9. 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}.

  10. 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.

  11. 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

  12. 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

  13. 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

  14. Increase in Energy Product of Nanocomposite Magnets from Multiple Pulse Laser Annealing of Amorphous Melt Spun Nd-Fe-B Precursors

    E-Print Network [OSTI]

    Hopkinson, David; Cockburn, Andrew; Sparkes, Martin; O’Neill, William

    2015-01-01

    superior nanocomposite magnets than conventional furnace annealing with an 18 % higher remanence, Mr, and a 60 % higher energy product, (BH)max. This improvement was attributed to refinement of grain sizes from > 20 nm to < 10 nm, facilitated...

  15. 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...

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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

  2. 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...

  3. 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...

  4. 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 &...

  5. 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...

  6. 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=

  7. 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

  8. 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

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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(

  16. 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.

  17. 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

  18. 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.

  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 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

  20. 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...

  1. 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

  2. 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

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. Beta-decay properties of neutron-rich Ge, Se, Kr, Sr, Ru, and Pd isotopes from deformed quasiparticle random-phase approximation

    E-Print Network [OSTI]

    P. Sarriguren

    2015-04-07

    Beta-decay properties of even and odd-A neutron-rich Ge, Se, Kr, Sr, Ru, and Pd isotopes involved in the astrophysical rapid neutron capture process are studied within a deformed proton-neutron quasiparticle random-phase approximation. The underlying mean field is described self-consistently from deformed Skyrme Hartree-Fock calculations with pairing correlations. Residual interactions in the particle-hole and particle-particle channels are also included in the formalism. The isotopic evolution of the various nuclear equilibrium shapes and the corresponding charge radii are investigated in all the isotopic chains. The energy distributions of the Gamow-Teller strength as well as the beta-decay half-lives are discussed and compared with the available experimental information. It is shown that nuclear deformation plays a significant role in the description of the decay properties in this mass region. Reliable predictions of the strength distributions are essential to evaluate decay rates in astrophysical scenarios.

  10. Surface chemical reactivity of ultrathin Pd(111) films on Ru(0001): Importance of orbital symmetry in the application of the d-band model

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

    Yin, Xiangshi; Cooper, Valentino R.; Weitering, Hanno H.; Snijders, Paul C.

    2015-09-22

    The chemical bonding of adsorbate molecules on transition-metal surfaces is strongly influenced by the hybridization between the molecular orbitals and the metal d-band. The strength of this interaction is often correlated with the location of the metal d-band center relative to the Fermi level. Here, we exploit finite size effects in the electronic structure of ultrathin Pd(111) films grown on Ru(0001) to tune their reactivity by changing the film thickness one atom layer at a time, while keeping all other variables unchanged. Interestingly, while bulk Pd(111) is reactive toward oxygen, Pd(111) films below five monolayers are surprisingly inert. This observationmore »is fully in line with the d-band model prediction when applied to the orbitals involved in the bonding. The shift of the d-band center with film thickness is primarily attributed to shifts in the partial density of states associated with the 4dxz and 4dyz orbitals. This study provides an in-depth look into the orbital specific contributions to the surface chemical reactivity, providing new insights that could be useful in surface catalysis.« less

  11. 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

  12. 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.

  13. 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

  14. 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).

  15. 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.

  16. 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

  17. 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.

  18. Crystal structure, magnetism and transport properties of Ce{sub 3}Ni{sub 25.75}Ru{sub 3.16}Al{sub 4.1}B{sub 10}

    SciTech Connect (OSTI)

    Janka, Oliver; Baumbach, Ryan E.; Thompson, Joe D.; Bauer, Eric D.; Kauzlarich, Susan M.

    2013-09-15

    Single crystals of Ce{sub 3}Ni{sub 25.75}Ru{sub 3.16}Al{sub 4.1}B{sub 10} were obtained from a process in which a polycrystalline sample of CeRu{sub 2}Al{sub 2}B was annealed in an excess of a Ni–In flux. The initial phase, CeRu{sub 2}Al{sub 2}B, does not recrystallize, instead, crystals of a new phase, Ce{sub 3}Ni{sub 25.75}Ru{sub 3.16}Al{sub 4.1}B{sub 10}, could be isolated once the flux was removed. The title compound crystallizes in the tetragonal space group P4/nmm (No. 129) with a=1139.02(8), c=801.68(6) pm (c/a=0.70) in the Nd{sub 3}Ni{sub 29}Si{sub 4}B{sub 10} structure type. Electrical resistivity measurements reveal metallic behavior with a minimum of 700 µ? cm and a small residual resistivity ratio of RRR=1.4 indicating a large amount of disorder scattering. The cerium atoms are either in the 4+ or an intermediate valence state with a valence fluctuation temperature far above room temperature. - Graphical abstract: Single crystals of Ce{sub 3}Ni{sub 25.75}Ru{sub 3.16}A{sub l4.1}B{sub 10} were obtained using a process in which a polycrystalline sample of CeRu{sub 2}Al{sub 2}B was annealed in an excess of a Ni–In flux. Electrical resistivity measurements reveal metallic behavior with a minimum of 700 ?? cm and a small residual resistivity ratio of RRR=1.4 indicating a large amount of disorder scattering. The cerium atoms are either in the 4+ or an intermediate valence state with a valence fluctuation temperature far above room temperature. Display Omitted - Highlights: • Flux synthesis of high quality single crystals of Ce{sub 3}Ni{sub 25.75}Ru{sub 3.16}Al{sub 4.1}B{sub 10} is presented along with the crystal structure, magnetic and transport properties. • The compound is isostructural to Nd{sub 3}Ni{sub 29}Si{sub 4}B{sub 10} but is first of this structure type showing mixed occupancies of d-elements. • This is an intermetallic phase with Ce in either the 4+ or an intermediate valence state. • The fact that this structure with mixed occupied transition metal sites exists suggests that more compounds of this type should be accessible and the physical properties tuned.

  19. 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...

  20. 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.

  1. 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%.

  2. 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.

  3. 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

  4. 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,

  5. Lightest Isotope of Bh Produced Via the 209Bi(52Cr,n)260Bh Reaction

    E-Print Network [OSTI]

    2007-01-01

    models. For many years, “cold fusion” reactions utilizingproduced via the new “cold fusion” reaction 209 Bi( 52 Cr,

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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...

  16. 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. ...

  17. Mechanistic insight into peroxydisulfate reactivity: Oxidation of the cis,cis-[Ru(bpy)2(OH2)]2O4+ "Blue Dimmer"

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

    Hurst, James K.; Roemeling, Margo D.; Lymar, Sergei V.

    2015-04-10

    One-electron oxidation of the ?-oxo dimer (cis,cis-[RuIII(bpy)2(OH2)]2O4+, {3,3}) to {3,4} by S2O82- can be described by three concurrent reaction pathways corresponding to the three protic forms of {3,3}. Free energy correlations of the rate constants, transient species dynamics determined by pulse radiolysis, and medium and temperature dependencies of the alkaline pathway all suggest that the rate determining step in these reactions is a strongly non-adiabatic dissociative electron transfer within a precursor ion pair leading to the {3,4}|SO42-|SO4•- ion triple. As deduced from the SO4•- scavenging experiments with 2-propanol, the SO4•- radical then either oxidizes {3,4} to {4,4} within the ionmore »triple, effecting a net two-electron oxidation of {3,3}, or escapes in solution with ~25 % probability to react with additional {3,3} and {3,4}, that is, effecting sequential one-electron oxidations. The reaction model presented also invokes rapid {3,3} + {4,4} ? 2{3,4} comproportionation, for which kcom ~5×107 M-1 s-1 was independently measured. The model provides an explanation for the observation that despite favorable energetics, no oxidation beyond the {3,4} state was detected. As a result, the indiscriminate nature of oxidation by SO4•- indicates that its fate must be quantitatively determined when using S2O82- as an oxidant« less

  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. 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.

  18. 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.

  19. 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

  20. 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

  1. 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.

  2. 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 (

  3. 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

  4. 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.

  5. 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

  6. 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

  7. 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 ...

  8. 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

  9. 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

  10. 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

  11. 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...

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. 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)

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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

  16. First-principles studies of structural stabilities and enthalpies of formation of refractory intermetallics: TM and TM3 (T = Ti, Zr, Hf; M = Ru, Rh, Pd, Os, Ir, Pt)

    SciTech Connect (OSTI)

    Xing, Weiwei; Chen, X.; Li, Dianzhong; Li, Y. Y.; Fu, Chong Long; Meschel, S.

    2012-01-01

    Using first-principles local density functional approach, we have calculated the ground-state structural phase stabilities and enthalpies of formation of thirty-six binary transition-metal refractory TM and TM3 compounds formed by Group IV elements T (T = Ti, Zr, Hf) and platinum group elements M (M = Ru, Rh, Pd, Os, Ir, Pt) . We compared our results with the available experimental data and found good agreement between theory and experiment in both the trends of structural stabilities and the magnitudes of formation enthalpies. Moreover, based on our calculated results, an empirical relationship between cohesive energies ( E) and melting temperatures (Tm) was derived as Tm = 0.0292 E/kB (where kB is the Boltzmann constant) for both TM and TM3 compounds.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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...

  6. 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}

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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}.

  12. 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.

  13. 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.

  14. 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...

  15. 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...

  16. 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

  17. 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.

  18. 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...

  19. 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.

  20. 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.

  1. 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...

  2. 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.

  3. 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...

  4. 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

  5. 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.

  6. 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...

  7. 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

  8. 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

  9. 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.

  10. 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

  11. 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.

  12. 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...

  13. 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...

  14. 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)...

  15. 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...

  16. 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.

  17. 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.

  18. 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...

  19. 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...

  20. 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

  1. 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?

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. 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...

  9. 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).

  10. 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.

  11. 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.

  12. 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.

  13. 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.}

  14. 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.

  15. 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.

  16. 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...

  17. 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.

  18. 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.

  19. 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.

  20. 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.