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Sample records for bh fe ru

  1. Electronic structure and magnetic properties of RuFe{sub 3}N nitride

    SciTech Connect (OSTI)

    Santos, A.V. dos; Kuhnen, C.A.

    2009-11-15

    Self-consistent band structure calculations were performed on nitride RuFe{sub 3}N in order to investigate its magnetic and ground state properties. The Linear Muffin-Tin Orbital (LMTO) method was employed and calculations were performed at several lattice parameters so as to obtain the RuFe{sub 3}N equilibrium volume. Nonmagnetic and ferromagnetic LMTO calculations have shown that the RuFe{sub 3}N stable stage is ferromagnetic with constant lattice equilibrium of 7.2502 atomic units (a.u.). At equilibrium volume the LMTO calculations have given magnetic moments of 1.25 and 1.63 mu{sub B} at Ru and Fe sites, respectively, and no magnetic moment at N sites. The analysis of states density at equilibrium volume as well as the results for charge transfer illustrates why this ruthenium nitride is ferromagnetic. The LMTO calculations anticipate that the magnetic moment, the hyperfine field (the Fermi contact) and the isomer shift show a strong dependence on the lattice spacing. - Graphical Abstract: Total energy curves, versus lattice spacing for the RuFe{sub 3}N nitride. It is observed an energy difference between ferromagnetic and paramagnetic states, which provides high critic pressure.

  2. Thermodynamics and superconductivity of Th7(Fe, Ru, Os, Co, Rh, Ir)3 system

    SciTech Connect (OSTI)

    Smith, James L; Lashley, Jason C; Volz, Heather M; Fisher, Robert A

    2008-01-01

    Expanding the temperature range of previous specific-heat measurements on the Th7(Fe, Ru, Os, Co, Rh, Ir)3 system, we measure the effect of transition-metal substitution on total entropy (S{sub 298 k}), electronic specific heat ({gamma}), and Debye temperature ({Theta}D). In addition we measure the pressure dependence, up to 10 kbar, of the superconducting transition.

  3. Tuning the magnetic and structural phase transitions of PrFeAsO via Fe/Ru spin dilution

    SciTech Connect (OSTI)

    Yiu, Yuen; Bonfa, Pietro; Sanna, Samuele; De Renzi, Roberto; Caretta, Pietro; McGuire, Michael A; Huq, Ashfia; Nagler, Stephen E

    2014-01-01

    Neutron diffraction and muon spin relaxation measurements are used to obtain a detailed phase diagram of PrFe1{xRuxAsO. The isoelectronic substitution of Ru for Fe acts eectively as spin dilution, suppressing both the structural and magnetic phase transitions. The temperature, TS, of the tetragonal-orthorhombic structural phase transition decreases gradually as a function of x. Slightly below TS coherent precessions of the muon spin are observed corresponding to static magnetism, possibly re ecting a signicant magneto-elastic coupling in the FeAs layers. Short range order in both the Fe and Pr moments persists for higher levels of x. The static magnetic moments disappear at a concentration coincident with that expected for percolation of the J1 - J2 square lattice model.

  4. Ru/FeCoB double layered film with high in-plane magnetic anisotropy field of 500 Oe

    SciTech Connect (OSTI)

    Hirata, Ken-ichiro; Hashimoto, Atsuto; Matsuu, Toshimitsu; Nakagawa, Shigeki

    2009-04-01

    FeCoB layers prepared on Ru underlayer possess a high saturation magnetization M{sub s} and a high in-plane magnetic anisotropy filed H{sub k}. Effects of preparation conditions were investigated. Low Ar gas pressure condition and thicker film thickness were effective to attain distortion of FeCo crystallite. As the crystallinity of Ru underlayer became higher, higher H{sub k} was induced. The accumulation of anisotropic stress in the film caused by the oblique incidences of depositing atoms with high energy seems to be one of the important effects to attain high anisotropy field. It was succeeded to prepare the Ru/FeCoB film with high H{sub k} of 500 Oe.

  5. 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 URu2xFexSi? 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 volumemoredetermined from our measurements and an isothermal compressibility ?T = 5.210? GPa? 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

  6. 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–xFexSi₂ 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 URu₂Si₂. Using the unit cell volume determinedmore » from our measurements and an isothermal compressibility κT = 5.2×10⁻³ GPa⁻¹ for URu₂Si₂, we determine the chemical pressure Pch in URu2−xFexSi₂ as a function of x. The resulting temperature T-chemical pressure Pch phase diagram for URu2−xFexSi₂ is in agreement with the established temperature T-external pressure P phase diagram of URu₂Si₂.« 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; 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.

  8. 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.

  9. Anomalous volume expansion in CaRu{sub 0.85}Fe{sub 0.15}O{sub 3}: Neutron powder diffraction and magnetic Compton scattering

    SciTech Connect (OSTI)

    Taniguchi, T.; Mizusaki, S.; Okada, N.; Nagata, Y.; Mori, K.; Wuernisha, T.; Kamiyama, T.; Hiraoka, N.; Itou, M.; Sakurai, Y.; Ozawa, T. C.; Noro, Y.; Samata, H.

    2007-01-01

    Neutron powder diffraction and magnetic Compton scattering measurements were conducted for ferromagnetic CaRu{sub 0.85}Fe{sub 0.15}O{sub 3} at temperatures between 10 and 300 K. Anomalous volume expansion was observed in the neutron diffraction measurement below the Curie temperature (85 K), and Invar-like behavior was observed below 40 K. However, no structural phase transition was observed down to 10 K. The strong correlation between the volume expansion, {delta}V, and the square magnetization, M{sup 2}, suggests that the anomalous volume expansion is due to the magnetovolume effect that is caused by the occurrence of ferromagnetism. The magnetic Compton scattering experiments revealed the existence of a magnetic moment on Ru and the antiferromagnetic configuration of Fe and Ru moments. The formation of a ferrimagnetic order through the induction of the magnetic moment on the Ru ion is a possible reason for the anomalous volume expansion observed for CaRu{sub 0.85}Fe{sub 0.15}O{sub 3}.

  10. 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.

  11. 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 Pt₇Ru₃ 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

  12. Fischer–Tropsch Synthesis: Effect of Reducing Agent for Aqueous-Phase Synthesis Over Ru Nanoparticle and Supported Ru Catalysts

    SciTech Connect (OSTI)

    Pendyala, Venkat Ramana Rao; Shafer, Wilson D.; Jacobs, Gary; Graham, Uschi M.; Khalid, Syed; Davis, Burtron H.

    2014-12-27

    The effect of the reducing agent on the performance of a ruthenium nanoparticle catalyst was investigated during aqueous-phase Fischer–Tropsch synthesis using a 1 L stirred tank reactor in the batch mode of operation. For the purpose of comparison, the activity and selectivity of NaY zeolite supported Ru catalyst were also studied. NaBH4 and hydrogen were used as reducing agents in our study, and hydrogen reduced catalysts exhibited higher activities than the NaBH4 reduced catalysts, because of higher extent of reduction and a relatively lower tendency toward agglomeration of Ru particles. The Ru nanoparticle catalyst displayed higher activities than the NaY zeolite supported Ru catalyst for both reducing agents. NaBH4 reduced catalysts are less active and the carbon dioxide selectivity is higher than the hydrogen reduced catalysts. The activity of the supported Ru catalyst (Ru/NaY) was 75 % of that of the Ru nanoparticle catalyst, and has the benefit of easy wax/catalyst slurry separation by filtration. Finally, the hydrogen reduced supported Ru catalyst exhibited superior selectivity towards hydrocarbons (higher C5+ selectivity and lower selectivity to methane) than all other catalysts tested.

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

    SciTech Connect (OSTI)

    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.; Janoschek, M.

    2015-02-26

    We have used specific heat and neutron diffraction measurements on single crystals of URu2–xFexSi₂ 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 URu₂Si₂. Using the unit cell volume determined from our measurements and an isothermal compressibility κT = 5.2×10⁻³ GPa⁻¹ for URu₂Si₂, we determine the chemical pressure Pch in URu2−xFexSi₂ as a function of x. The resulting temperature T-chemical pressure Pch phase diagram for URu2−xFexSi₂ is in agreement with the established temperature T-external pressure P phase diagram of URu₂Si₂.

  14. Synthesis, crystal structure investigation and magnetism of the complex metal-rich boride series Cr{sub x}(Rh{sub 1-y}Ru{sub y}){sub 7-x}B{sub 3} (x=0.88-1; y=0-1) with Th{sub 7}Fe{sub 3}-type structure

    SciTech Connect (OSTI)

    Misse, Patrick R.N.; Mbarki, Mohammed; Fokwa, Boniface P.T.

    2012-08-15

    Powder samples and single crystals of the new complex boride series Cr{sub x}(Rh{sub 1-y}Ru{sub y}){sub 7-x}B{sub 3} (x=0.88-1; y=0-1) have been synthesized by arc-melting the elements under purified argon atmosphere on a water-cooled copper crucible. The products, which have metallic luster, were structurally characterized by single-crystal and powder X-ray diffraction as well as EDX measurements. Within the whole solid solution range the hexagonal Th{sub 7}Fe{sub 3} structure type (space group P6{sub 3}mc, no. 186, Z=2) was identified. Single-crystal structure refinement results indicate the presence of chromium at two sites (6c and 2b) of the available three metal Wyckoff sites, with a pronounced preference for the 6c site. An unexpected Rh/Ru site preference was found in the Ru-rich region only, leading to two different magnetic behaviors in the solid solution: The Rh-rich region shows a temperature-independent (Pauli) paramagnetism whereas an additional temperature-dependent paramagnetic component is found in the Ru-rich region. - Graphical abstract: The new complex boride series Cr{sub x}(Rh{sub 1-y}Ru{sub y}){sub 7-x}B{sub 3} (x=0.88-1; y=0-1) has been synthesized by arc melting the elements under purified argon atmosphere. Beside the 3d/4d site preference within the whole solid solution, an unexpected Rh/Ru site preference was found in the Ru-rich region only, leading to two different magnetic behaviors: The Rh-rich region shows a temperature-independent (Pauli) paramagnetism whereas an additional temperature-dependent paramagnetic component is found in the Ru-rich region. Highlights: Black-Right-Pointing-Pointer Synthesis of a new boride series fulfilling Vegard Acute-Accent s rule. Black-Right-Pointing-Pointer 3d/4d site preference. Black-Right-Pointing-Pointer Unexpected Ru/Rh site preference. Black-Right-Pointing-Pointer Rh-rich region is Pauli paramagnetic. Black-Right-Pointing-Pointer Ru-rich region is Pauli and temperature-dependent paramagnetic.

  15. Adsorption and diffusion of Ru adatoms on Ru(0001)-supported...

    Office of Scientific and Technical Information (OSTI)

    Accepted Manuscript: Adsorption and diffusion of Ru adatoms on Ru(0001)-supported graphene: Large-scale first-principles calculations This content will become publicly available on...

  16. 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; Heitmann, Tom; Montfrooij, Wouter

    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 temperaturesresulting from chemical dopingleads 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 dynamicssuch as the growth of the correlation length upon coolingcan 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.

  17. Doc.~:Ru.

    Office of Legacy Management (LM)

    .' , .' c,j .c; Distriblition:~ ;. <; ~..,:L.D.i&%.ay,FiN-OR00 Doc.~:Ru. ,.,. 75. ' Br..Reading 'ire' ,lliv. Read&q File ,: '. ~ ,, .-' . ...: - SURNAME..

  18. The series of carbon-chain complexes {Ru(dppe)Cp*}?{?-(C?C)x} (x = 48, 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 = 48, 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 = 216 were measured and showed a diminution of the separation of

  19. Microsoft Word - P450-I bh

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

    analyzed at Beam Line 7-3 at SSRL. Extended x-ray absorption fine structure (EXAFS) studies on multiple sets of samples revealed that the Fe-S bond in P450-I was in fact 0.09 ...

  20. Bulk modulus and specific heat of B-site doped (La{sub 0.3}Pr{sub 0.7}){sub 0.65}Ca{sub 0.35}Mn{sub 1−x}B{sub x}O{sub 3} (B=Fe, Cr, Ru, Al, Ga)

    SciTech Connect (OSTI)

    Srivastava, Archana; Thakur, Rasna; Gaur, N. K.

    2014-04-24

    Specific heat (C{sub p}) thermal expansion (α) and Bulk modulus (B{sub T}) of lightly doped Rare Earth manganites (La{sub 0.3}Pr{sub 0.7}){sub 0.65}Ca{sub 0.35}Mn{sub 1−x}B{sub x}O{sub 3} (B{sup 3+} = Fe{sup 3+},Cr{sup 3+},Ga{sup 3+},Al{sup 3+},Ru4+); (0.3Fe{sub 0.03}O{sub 3} as a function of temperature (10K≤T≤ 200K) is found to be in agreement with the published data. The trend of variation of Debye temperature with B-site cationic radius is predicted probably for the first time for the B-site doped rare earth manganites.

  1. Effect of Ru thickness on spin pumping in Ru/Py bilayer

    SciTech Connect (OSTI)

    Behera, Nilamani; Singh, M. Sanjoy; Chaudhary, Sujeet; Pandya, Dinesh K. Muduli, P. K.

    2015-05-07

    We report the effect of Ru thickness (t{sub Ru}) on ferromagnetic resonance (FMR) line-width of Ru(t{sub Ru})/Py(23?nm) bilayer samples grown on Si(100)/SiO{sub 2} substrates at room temperature by magnetron sputtering. The FMR line-width is found to vary linearly with frequency for all thicknesses of Ru, indicating intrinsic origin of damping. For Ru thicknesses below 15?nm, Gilbert-damping parameter, ? is almost constant. We ascribe this behavior to spin back flow that is operative for Ru thicknesses lower than the spin diffusion length in Ru, ?{sub sd}. For thicknesses >15?nm (>?{sub sd}), the damping constant increases with Ru thickness, indicating spin pumping from Py into Ru.

  2. 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.

  3. 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.

  4. Energiegesellschaft Nordost mBH e n o | Open Energy Information

    Open Energy Info (EERE)

    Energiegesellschaft Nordost mBH e n o Jump to: navigation, search Name: Energiegesellschaft Nordost mBH (e.n.o.) Place: Germany Sector: Renewable Energy, Wind energy Product:...

  5. Structural and Architectural Evaluation of Bimetallic Nanoparticles: A Case Study of Pt−Ru Core−Shell and Alloy Nanoparticles

    SciTech Connect (OSTI)

    Alayoglu, S.; Zavalij, P; Eichhorn, B; Wang, Q; Frenkel, A; Chupas, P

    2009-01-01

    A comprehensive structural/architectural evaluation of the PtRu (1:1) alloy and Ru at Pt core-shell nanoparticles (NPs) provides spatially resolved structural information on sub-5 nm NPs. A combination of extended X-ray absorption fine structure (EXAFS), X-ray absorption near edge structure (XANES), pair distribution function (PDF) analyses, Debye function simulations of X-ray diffraction (XRD), and field emission transmission electron microscopy/energy dispersive spectroscopy (FE-TEM/EDS) analyses provides complementary information used to construct a detailed picture of the core/shell and alloy nanostructures. The 4.4 nm PtRu (1:1) alloys are crystalline homogeneous random alloys with little twinning in a typical face-centered cubic (fcc) cell. The Pt atoms are predominantly metallic, whereas the Ru atoms are partially oxidized and are presumably located on the NP surface. The 4.0 nm Ru at Pt NPs have highly distorted hcp Ru cores that are primarily in the metallic state but show little order beyond 8 A. In contrast, the 1-2 monolayer thick Pt shells are relatively crystalline but are slightly distorted (compressed) relative to bulk fcc Pt. The homo- and heterometallic coordination numbers and bond lengths are equal to those predicted by the model cluster structure, showing that the Ru and Pt metals remain phase-separated in the core and shell components and that the interface between the core and shell is quite normal.

  6. Facile oxygen intercalation between full layer graphene and Ru...

    Office of Scientific and Technical Information (OSTI)

    Facile oxygen intercalation between full layer graphene and Ru(0001) under ambient ... Title: Facile oxygen intercalation between full layer graphene and Ru(0001) under ambient ...

  7. Arrays of Ru Nanoclusters with Narrow Size Distribution Templated by Monolayer Graphene on Ru

    SciTech Connect (OSTI)

    Sutter, P.; Sutter, E.; Albrecht, P.; Wang, B.; Bocquet M.-L.; Wu, L.; Zhu, Y.

    2011-09-01

    Ru nanoclusters self-assemble over macroscopic sample areas during vapor deposition of Ru on monolayer graphene (MLG) on Ru(0001). The Ru nanoclusters form arrays with a mean lateral cluster diameter of {approx} 20 {angstrom}, cluster heights of 1 or 2 ML, and a size distribution that remains nearly constant with increasing coverage. Combined scanning tunneling microscopy and density functional theory (DFT) show that the clusters are templated by the MLG/Ru(0001) moire unit cell and identify the preferred binding site of the clusters as the low fcc region of the moire. Cross-sectional transmission electron microscopy (TEM) and high-resolution TEM contrast simulations experimentally demonstrate that the interaction of the Ru clusters with the underlying MLG/Ru(0001) leads to a local lifting of the graphene layer of the template. DFT calculations confirm this mechanism of interaction of the Ru clusters with the strongly coupled MLG/Ru(0001). Weakening of the graphene-support coupling via oxygen intercalation is shown to have a major effect on the assembly of Ru nanocluster arrays. With a preferred binding site lacking on decoupled graphene, the Ru nanoclusters grow significantly larger, and clusters with 1 to 4 ML height can coexist.

  8. Microsoft Word - Orbital_Reconstruction bh pp2 changes accepted...

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

    Role of an Oxygen Vacancy Nanostructure on the Switchable Photovoltaic Effect in BiFeO 3 ... Moreover, a switchable photovoltaic effect and its diode effect have been demonstrated. 2 ...

  9. 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.

  10. 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

  11. Preparation of MgH{sub 2} composite with a composition of 40%MgH{sub 2} + 30%LiBH{sub 4} + 30%(2LiBH{sub 4} + MgF{sub 2})

    SciTech Connect (OSTI)

    Hong, Seong-Hyeon; Song, Myoung Youp

    2012-09-15

    Graphical abstract: Hydrogen content vs. desorption time curves for consecutive 1st desorptions of 40 wt%MgH{sub 2} + 30 wt%LiBH{sub 4} + 30 wt%(2LiBH{sub 4} + MgF{sub 2}) at 533–873 K. Highlights: ► Addition of MgF{sub 2} and LiBH{sub 4} with a higher hydrogen storage capacity to MgH{sub 2}. ► Preparation of 40%MgH{sub 2} + 30%LiBH{sub 4} + 30% (2LiBH{sub 4} + MgF{sub 2}) composite. ► Examination of desorption properties of the composite. ► Total desorbed hydrogen quantity for consecutive 1st desorptions of 7.07 wt%. ► Reactions of LiBH{sub 4} → LiH + B + (3/2)H{sub 2}, and 2LiBH{sub 4} + MgF{sub 2} → 2LiF + MgB{sub 2} + 4H{sub 2}. -- Abstract: A mixture of containing two chemical equivalents of lithium borohyride and one equivalent of magnesium fluoride is known to yield hydrogen in an amount of about 7.6 wt% of the mixture when heated to about 150 °C at atmospheric pressure by the following reaction; 2LiBH{sub 4} + MgF{sub 2} = 2LiF + MgB{sub 2} + 4H{sub 2}. In order to increase hydrogen storage capacity of Mg-based materials, a mixture with a composition of 2LiBH{sub 4} + MgF{sub 2} and LiBH{sub 4}with a higher hydrogen storage capacity of 18.4 wt% were added to MgH{sub 2}. MgH{sub 2} composite with a composition of 40 wt%MgH{sub 2} + 30 wt%LiBH{sub 4} + 30 wt%(2LiBH{sub 4} + MgF{sub 2}) was prepared by reactive mechanical grinding. The hydrogen storage properties of the sample were then examined. Hydrogen content vs. desorption time curves for consecutive 1st desorptions of 40 wt%MgH{sub 2} + 30 wt%LiBH{sub 4} + 30 wt%(2LiBH{sub 4} + MgF{sub 2}) at 533–873 K showed that the total desorbed hydrogen quantity for consecutive 1st desorptions is 7.07 wt%.

  12. 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.

  13. First-principles calculated decomposition pathways for LiBH4 nanoclusters

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

    Huang, Zhi -Quan; Chen, Wei -Chih; Chuang, Feng -Chuan; Majzoub, Eric H.; Ozolins, Vidvuds

    2016-05-18

    Here, we analyze thermodynamic stability and decomposition pathways of LiBH4 nanoclusters using grand-canonical free-energy minimization based on total energies and vibrational frequencies obtained from density-functional theory (DFT) calculations. We consider (LiBH4)n nanoclusters with n = 2 to 12 as reactants, while the possible products include (Li)n, (B)n, (LiB)n, (LiH)n, and Li2BnHn; off-stoichiometric LinBnHm (m ≤ 4n) clusters were considered for n = 2, 3, and 6. Cluster ground-state configurations have been predicted using prototype electrostatic ground-state (PEGS) and genetic algorithm (GA) based structural optimizations. Free-energy calculations show hydrogen release pathways markedly differ from those in bulk LiBH4. While experiments havemore » found that the bulk material decomposes into LiH and B, with Li2B12H12 as a kinetically inhibited intermediate phase, (LiBH4)n nanoclusters with n ≤ 12 are predicted to decompose into mixed LinBn clusters via a series of intermediate clusters of LinBnHm (m ≤ 4n). The calculated pressure-composition isotherms and temperature-pressure isobars exhibit sloping plateaus due to finite size effects on reaction thermodynamics. Generally, decomposition temperatures of free-standing clusters are found to increase with decreasing cluster size due to thermodynamic destabilization of reaction products.« less

  14. WWS-ceremony-WW%2C-LAJ%2C-BH_crop.jpg | OSTI, US Dept of Energy Office of

    Office of Scientific and Technical Information (OSTI)

    Scientific and Technical Information WWS-ceremony-WW%2C-LAJ%2C-BH_crop

  15. MoRu/Be multilayers for extreme ultraviolet applications

    DOE Patents [OSTI]

    Bajt, Sasa C.; Wall, Mark A.

    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.

  16. Adsorption and diffusion of Ru adatoms on Ru(0001)-supported graphene: Large-scale first-principles calculations

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

    Han, Yong; Evans, James W.

    2015-10-27

    Large-scale first-principles density functional theory calculations are performed to investigate the adsorption and diffusion of Ru adatoms on monolayer graphene (G) supported on Ru(0001). The G sheet exhibits a periodic moiré-cell superstructure due to lattice mismatch. Within a moiré cell, there are three distinct regions: fcc, hcp, and mound, in which the C6-ring center is above a fcc site, a hcp site, and a surface Ru atom of Ru(0001), respectively. The adsorption energy of a Ru adatom is evaluated at specific sites in these distinct regions. We find the strongest binding at an adsorption site above a C atom inmore » the fcc region, next strongest in the hcp region, then the fcc-hcp boundary (ridge) between these regions, and the weakest binding in the mound region. Behavior is similar to that observed from small-unit-cell calculations of Habenicht et al. [Top. Catal. 57, 69 (2014)], which differ from previous large-scale calculations. We determine the minimum-energy path for local diffusion near the center of the fcc region and obtain a local diffusion barrier of ~0.48 eV. We also estimate a significantly lower local diffusion barrier in the ridge region. These barriers and information on the adsorption energy variation facilitate development of a realistic model for the global potential energy surface for Ru adatoms. Furthermore, this in turn enables simulation studies elucidating diffusion-mediated directed-assembly of Ru nanoclusters during deposition of Ru on G/Ru(0001).« less

  17. Adsorption and diffusion of Ru adatoms on Ru(0001)-supported graphene: Large-scale first-principles calculations

    SciTech Connect (OSTI)

    Han, Yong; Evans, James W.

    2015-10-27

    Large-scale first-principles density functional theory calculations are performed to investigate the adsorption and diffusion of Ru adatoms on monolayer graphene (G) supported on Ru(0001). The G sheet exhibits a periodic moiré-cell superstructure due to lattice mismatch. Within a moiré cell, there are three distinct regions: fcc, hcp, and mound, in which the C6-ring center is above a fcc site, a hcp site, and a surface Ru atom of Ru(0001), respectively. The adsorption energy of a Ru adatom is evaluated at specific sites in these distinct regions. We find the strongest binding at an adsorption site above a C atom in the fcc region, next strongest in the hcp region, then the fcc-hcp boundary (ridge) between these regions, and the weakest binding in the mound region. Behavior is similar to that observed from small-unit-cell calculations of Habenicht et al. [Top. Catal. 57, 69 (2014)], which differ from previous large-scale calculations. We determine the minimum-energy path for local diffusion near the center of the fcc region and obtain a local diffusion barrier of ~0.48 eV. We also estimate a significantly lower local diffusion barrier in the ridge region. These barriers and information on the adsorption energy variation facilitate development of a realistic model for the global potential energy surface for Ru adatoms. Furthermore, this in turn enables simulation studies elucidating diffusion-mediated directed-assembly of Ru nanoclusters during deposition of Ru on G/Ru(0001).

  18. Santa Fe

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

    International science conferences in Santa Fe June 22, 2012 Focus on insulating materials and radiation effects in solids LOS ALAMOS, New Mexico, June 22, 2012-Los Alamos National...

  19. 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.

  20. Santa Fe

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

    International science conferences in Santa Fe June 22, 2012 Focus on insulating materials and radiation effects in solids LOS ALAMOS, New Mexico, June 22, 2012-Los Alamos National Laboratory together with New Mexico Consortium, Los Alamos National Bank and Netzsch Group are sponsoring two international conferences in Santa Fe. Organizers anticipate the arrival of more than 300 scientists from around the world. What: * The 2012 International Conference on Defects in Insulating Materials is the

  1. Stability of B-H and B-D complexes in diamond under electron beam excitation

    SciTech Connect (OSTI)

    Barjon, J.; Mehdaoui, A.; Jomard, F.; Chevallier, J.; Mer, C.; Nesladek, M.; Bergonzo, P.; Pernot, J.; Omnes, F.; Deneuville, A.

    2008-08-11

    The substitution of hydrogen by deuterium is generally known to increase the stability of the defect passivation in semiconductors, occasionally giving rise to giant isotope effects. In this work, the stability under an electron beam irradiation of boron-hydrogen and boron-deuterium pairs in diamond are compared. The dissociation kinetics was followed in situ by cathodoluminescence spectroscopy. Surprisingly, B-H complexes are more stable than B-D complexes under electron beam at low temperature ({approx}100 K), with a dissociation rate about twice smaller. These experimental results are coherent with a dissociation mechanism involving a cumulative vibrational excitation of the complexes.

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

    SciTech Connect (OSTI)

    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 AucoreRushell 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 selectivity 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.

  3. Spin-memory loss at Co/Ru interfaces (Journal Article) | DOE...

    Office of Scientific and Technical Information (OSTI)

    Spin-memory loss at CoRu interfaces Title: Spin-memory loss at CoRu interfaces Authors: Khasawneh, Mazin A. ; Klose, Carolin ; Pratt, W. P. ; Birge, Norman O. Publication Date: ...

  4. Enhanced thermoelectric power and electronic correlations in RuSe₂

    SciTech Connect (OSTI)

    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 Ru₁₋xIrxSe₂ (x ≤ 0.2). RuSe₂ is a semiconductor that crystallizes in a cubic pyrite unit cell. The Seebeck coefficient of RuSe₂ 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. 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.

  5. 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.

    2015-03-03

    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 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. 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.

  6. 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.

  7. Nuclear forward scattering of synchrotron radiation by 99Ru

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

    Bessas, D.; Merkel, D. G.; Chumakov, A. I.; Ruffer, R.; Hermann, Raphael P.; Sergueev, I.; Mahmoud, A.; Klobes, B.; McGuire, Michael A.; Sougrati, M. T.; et al

    2014-10-03

    In this study, we measured nuclear forward scattering spectra utilizing the 99Ru transition, 89.571(3) keV, with a notably mixed E2/M1 multipolarity. The extension of the standard evaluation routines to include mixed multipolarity allows us to extract electric and magnetic hyperfine interactions from 99Ru-containing compounds. This paves the way for several other high-energy Mössbauer transitions, E~90 keV. Lastly, the high energy of such transitions allows for operando nuclear forward scattering studies in real devices.

  8. 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.

  9. Multiple Pathways for Benzyl Alcohol Oxidation by RuV=O3+ and RuIV=O2+

    SciTech Connect (OSTI)

    Paul, Amit; Hull, Jonathan F.; Norris, Michael R.; Chen, Zuofeng; Ess, Daniel H.; Concepcion, Javier J.; Meyer, Thomas J.

    2011-01-20

    Significant rate enhancements are found for benzyl alcohol oxidation by the RuV=O3+ form of the water oxidation catalyst [Ru(Mebimpy)(bpy)(OH2)]2+ [Mebimpy = 2,6-bis(1-methylbenzimidazol-2-yl)pyridine; bpy = 2,2'-bipyridine] compared to RuIV=O2+ and for the RuIV=O2+ form with added bases due to a new pathway, concerted hydride proton transfer (HPT).

  10. Multiple Pathways for Benzyl Alcohol Oxidation by RuV=O3+ and RuIV=O2+

    SciTech Connect (OSTI)

    Paul, Amit; Hull, Jonathan F.; Norris, Michael R.; Chen, Zuofeng; Ess, Daniel H.; Concepcion, Javier J.; Meyer, Thomas J.

    2011-01-20

    Significant rate enhancements are found for benzyl alcohol oxidation by the RuV=O3+ form of the water oxidation catalyst [Ru(Mebimpy)(bpy)(OH2)]2+ [Mebimpy = 2,6-bis(1-methylbenzimidazol-2-yl)pyridine; bpy = 2,2'-bipyridine] compared to RuIV=O2+ and for the RuIV=O2+ form with added bases due to a new pathway involving concerted hydride proton transfer (HPT).

  11. 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 0.1moreM 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? Pt, as compared to that of commercially available Pt nanoparticles (0.107 mA ?g? 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

  12. 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, Pd₃Ru, and Pd₉Ru 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 Pd₉Ru/C exhibits the strongest electrocatalytic activity for oxygen reduction reaction (ORR) in an oxygen-saturated 0.1more » M aqueous HClO₄ solution. Subsequently, the Pd₉Ru/C undegoes Cu under potential deposition, followed by a galvanic displacement reaction to deposit a Pt monolayer on the Pd₉Ru surface (Pd₉Ru@Pt). The Pd₉Ru@Pt reveals better ORR performance than that of Pt, reaching a mass activity of 0.38 mA μg⁻¹ Pt, as compared to that of commercially available Pt nanoparticles (0.107 mA μg⁻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 Pd₉Ru@Pt electrocatalyst represents a substantial reduction in the amount of Pt consumption and raw material cost.« less

  13. 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.

  14. 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).

  15. Measurement of 3H in soil cores from the Hyrax Event (U3bh) subsidence crater

    SciTech Connect (OSTI)

    Kreek, S.; Hudson, G.B.; Ruth, M.

    1996-07-01

    Core samples were collected from two boreholes drilled in the subsidence crater of the Hyrax event (U3bh). The moisture in the core samples was extracted via freeze drying and tritiw-n was measured in the extracted moisture via `He accumulation mass spectrometry or liquid scintillation counting. Elevated tritium concentrations (IE4 - IE6 pCi/L extracted moisture as of the time of measurement) were observed in the extracted moisture from virtually all of the core samples with significant increases beginning at about 30 ft depth. No longer-lived fission products (144 Ce) or activation products (`OCo, `Eu, 114 En) were observed by gamma-ray spectroscopy in a subset of the core samples. This likely indicates that a catastrophic failure of containment (if it occurred) did not release significant radioactivities to this shallow depth (30 ft). The presence of `Cs at much greater depths (@210 ft, 64 m) may indicate that gaseous and/or vapor products were released shortly after the Hyrax event to a depth of about 210 ft. The relatively shallow depth where the elevated tritium is observed makes highly improbable any significant linkage between the elevated tritium concentrations and a Hyrax event containment failure. This may indicate that an additional source of enriched `H was introduced at this site.

  16. High performance Nd-Fe-B permanent magnets without critical elements

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

    Pathak, Arjun K.; Gschneidner, Jr., K. A.; Khan, M.; McCallum, R. W.; Pecharsky, V. K.

    2016-01-28

    Scanning electron microscopy, and magnetization measurements reveal that as cast (Nd1–xCex)2Fe14B alloys contain significant amounts of α-Fe that can be dramatically reduced by annealing the alloys at 1000 °C for 3 days. The room temperature intrinsic coercivity, Hci, of (Nd0.8Ce0.2)2.2Fe14B melt spun ribbons was found to be 11 kOe, which is ~32 to ~10% higher in comparison to that of Nd2Fe14B (Hci = 8.3 kOe), and (Nd0.8Ce0.2)2.0Fe14B (Hci = 10 kOe), respectively. The substitution of Co for Fe in (Nd0.8Ce0.2)2Fe14–zCozB significantly increases both TC and the maximum energy product, (BH)max. Our study shows that both Co-containing and Co-free Ce-substituted Nd2Fe14Bmore » alloys have excellent magnetic properties at room temperature and above. As a result, the experimental results also demonstrate the potential of Nd-Ce-Fe-TM-B based alloys as alternative to expensive Dy-containing high performance rare earth magnets.« less

  17. Isotopic fractionation associated with [NiFe]- and [FeFe]-hydrogenases...

    Office of Scientific and Technical Information (OSTI)

    Isotopic fractionation associated with NiFe- and FeFe-hydrogenases Citation Details In-Document Search Title: Isotopic fractionation associated with NiFe- and ...

  18. miniFE

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

    miniFE miniFE Description FE is a Finite Element mini-application which implements a couple of kernels representative of implicit finite-element applications. It assembles a sparse...

  19. Magnetic properties and spin polarization of Ru doped half metallic CrO{sub 2}

    SciTech Connect (OSTI)

    West, Kevin G.; Dao, Nam N. H.; Lu, Jiwei; Osofsky, Michael; Mazin, I. I.; Wolf, Stuart A.

    2015-07-06

    Chromium dioxide (CrO{sub 2}) is a half metal that is of interest for spintronic devices. It has not been synthesized through traditional physical vapor deposition (PVD) techniques because of its thermodynamic instability in low oxygen pressures. Epitaxial thin films of Ru doped tetragonal rutile CrO{sub 2} were synthesized by a PVD technique. The as-deposited Ru{sub x}Cr{sub 1−x}O{sub 2} was ferrimagnetic with the saturation magnetization moment showing a strong dependence on the Ru concentration. Curie temperature as high as 241 K has been obtained for ∼23 at. % Ru. The Ru substitution increased the electrical conductivity by increasing the minority spin concentration. The spin polarization was found to be as high as 70% for 9 at. % Ru and decreased to ∼60% with Ru concentrations up to ∼44 at. %, which is determined by the Fermi velocities of the majority and minority spins. First principle calculations were performed to understand the effect of Ru content on the properties of CrO{sub 2}. The PVD processes of Ru doped CrO{sub 2} could lead to the practical applications of the high spin polarization of CrO{sub 2} in spintronic devices.

  20. Sol-gel Ru/SiO[sub 2] - catalysts: Theoretical and experimental determination of the Ru-in-silica structures

    SciTech Connect (OSTI)

    Lopez, T.; Gomez, R.; Novaro, O. ); Ramirez-Solis, A.; Sanchez-Mora, E.; Castillo, S.; Poulain, E.; Martinez-Magadan, J.M. )

    1993-05-01

    Preparation of Ru/SiO[sub 2] catalysts with sol-gel techniques allows better selectivity and much greater resistance to coke formation and deactivation than the traditional impregnation method. This has been attributed to the incorporation of Ru into the silica network for the sol-gel catalyst. To further understand the structure of the Ru occluded in the silica network, a variety of spectroscopical studies and quantum mechanical calculations were carried out, confirming previously proposed structures and showing good agreement between the theoretical and experimental results. 26 refs., 10 figs., 2 tabs.

  1. Low leakage Ru-strontium titanate-Ru metal-insulator-metal capacitors for sub-20 nm technology node in dynamic random access memory

    SciTech Connect (OSTI)

    Popovici, M. Swerts, J.; Redolfi, A.; Kaczer, B.; Aoulaiche, M.; Radu, I.; Clima, S.; Everaert, J.-L.; Van Elshocht, S.; Jurczak, M.

    2014-02-24

    Improved metal-insulator-metal capacitor (MIMCAP) stacks with strontium titanate (STO) as dielectric sandwiched between Ru as top and bottom electrode are shown. The Ru/STO/Ru stack demonstrates clearly its potential to reach sub-20 nm technology nodes for dynamic random access memory. Downscaling of the equivalent oxide thickness, leakage current density (J{sub g}) of the MIMCAPs, and physical thickness of the STO have been realized by control of the Sr/Ti ratio and grain size using a heterogeneous TiO{sub 2}/STO based nanolaminate stack deposition and a two-step crystallization anneal. Replacement of TiN with Ru as both top and bottom electrodes reduces the amount of electrically active defects and is essential to achieve a low leakage current in the MIM capacitor.

  2. 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.

  3. Enhanced oxygen evolution activity of IrO2 and RuO2 (100) surfaces...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Enhanced oxygen evolution activity of IrO2 and RuO2 (100) surfaces Citation Details In-Document Search ... Here we report that the (100) surface of IrO2 and RuO2 is ...

  4. The Thermal Behavior of Pd on Graphene/Ru(0001)

    SciTech Connect (OSTI)

    Yi, Cheol-Woo W.; Szanyi, Janos

    2015-11-01

    The thermal behavior of various amounts of palladium deposited onto graphene/Ru(0001) at room temperature was investigated by x-ray photoelectron spectroscopy (XPS) and infrared reflection absorption spectroscopy (IRAS) of adsorbed CO. IRAS spectra of adsorbed CO on palladium deposited onto the graphene layer reveal the formation of defect-rich, highly-stepped and/or nanoparticle-typed palladium clusters. Annealing to temperatures below ~900 K, palladium clusters mainly experience agglomeration on the graphene layer, but at higher temperatures intercalation of palladium between the graphene layer and Ru substrate takes place. Eventually, palladium completely desorbs and the graphene layer dissolves into the ruthenium substrate at 1400 K. Even though the annealing induces the intercalation and desorption of palladium, the topmost graphene layer stays intact without any physical damage at and below 1300 K. We gratefully acknowledge the US Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division for the support of this work. The research described in this article was performed at the Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by the DOE Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory (PNNL). PNNL is operated for the US DOE by Battelle Memorial Institute under contract number DE-AC05-76RL01830. CWY also acknowledges the support of this work by Sungshin Women’s University Research Grant of 2014.

  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) μB/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? Pt, as compared to that of commercially available Pt nanoparticles (0.107 mA ?g? 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. Fabrication of MgAl{sub 2}O{sub 4} tunnel barrier by radio frequency-sputtering method and magnetoresistance effect through it with Fe or Fe{sub 4}N ferromagnetic electrode

    SciTech Connect (OSTI)

    Tsunoda, Masakiyo; Chiba, Ryoichi; Kabara, Kazuki

    2015-05-07

    Spinel MgAl{sub 2}O{sub 4} thin films were deposited on MgO single-crystal substrates and epitaxial Fe (or Fe{sub 4}N) thin films by RF-sputtering from a ceramic target. Epitaxial relationship was confirmed by X-ray diffraction analysis between the crystalline spinel MgAl{sub 2}O{sub 4} films and the respective substrate and underlayers, while no diffraction peak was observed from the films deposited on amorphous substrates. Spin-valve type magnetic tunnel junctions (MTJs) with a stacking structure of Fe [Fe{sub 4}N]/MgAl{sub 2}O{sub 4}/CoFeB/Ru/Fe/MnIr exhibited normal [inverse] tunnel magnetoresistance (TMR) effect, reflecting the sign of spin polarization of Fe [Fe{sub 4}N]. The maximum magnitude of the TMR ratio obtained for the Fe-based and Fe{sub 4}N-based MTJs was 67% and 18%, respectively. The resistance area product values of the MTJs were significantly larger than the reported values for the MTJs with a post-oxidized spinel MgAl{sub 2}O{sub 4} barrier.

  8. Getting to Santa Fe

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

    Getting to Santa Fe Getting to Santa Fe Find quick links on hotel and transportation information. Explore the surrounding area while you visit Santa Fe. Institute Administrator Caryll Blount Institute for Materials Science (505) 665-3950 Email La Fonda La Fonda on the Plaza 100 E. San Francisco St. Santa Fe, NM 87501 General phone numbers: 1-505-982-5511 1-800-523-5002 Concierge (Rebekah): concierge@lafondasantafe.com Additional Travel Information Santa Fe Travel site: This site provides you

  9. 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.

  10. Tuning the metal-insulator crossover and magnetism in SrRuO3...

    Office of Scientific and Technical Information (OSTI)

    in SrRuO3 by ionic gating Reversible control of charge transport and magnetic ... We report a reversible control of charge transport, metal-insulator crossover and ...

  11. Mechanism of water oxidation by [Ru(bda)(L)₂]: The return of the "blue dimer"

    SciTech Connect (OSTI)

    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)₂] 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)₂], revealing key features unavailable from solution studies with sacrificial oxidants.

  12. 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.}

  13. New insights into the thermodynamic behavior of 2LiBH4-MgH2 composite for hydrogen storage

    SciTech Connect (OSTI)

    Cova, Federico; Ronnebro, Ewa; Choi, Yong-Joon; Gennari, Fabiana; Larochette, Pierre

    2015-06-15

    The composite 2LiBH4:MgH2 has been studied as a possible hydrogen storage material due to its high storage capacity. The present work is directed towards the clarification of the thermodynamic behavior of the system, especially in the temperature region above 400C. We reveal different reaction paths during hydrogen absorption and desorption at various temperatures which has important implication for applications. At temperatures higher than 413C, the observation of two different absorption pressure plateaus indicates that two different reactions occur, however, below this temperature there is only one plateau present in the system. During desorption, the double plateau can be observed at temperatures as low as 375C.

  14. Excitation function for the production of 262Bh (Z = 107) in theodd-Z projectile reaction 208Pb(55Mn, n)

    SciTech Connect (OSTI)

    Folden III, C.M.; Nelson, S.L.; Dullmann, Ch.E.; Schwantes, J.M.; Sudowe, R.; Zielinski, P.M.; Gregorich, K.E.; Nitsche, H.; Hoffman, D.C.

    2005-05-16

    The excitation function for production of 262Bh in the odd-Z-projectile reaction 208Pb(55Mn,n) has been measured at three projectile energies using the Berkeley Gas-filled Separator at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron. In total, 33 decay chains originating from 262Bh and 2 decay chains originating from 261Bh were observed. The measured decay properties are in good agreement with previous reports. The maximum cross section of 540 +180 - 150 pb is observed at a lab-frame center-of-target energy of 264.0 MeV and is more than fives times larger than that expected based on previously reported results for production of 262Bh in the analogous even-Z-projectile reaction 209Bi(54Cr,n). Our results indicate that the optimum beam energy in one-neutron-out heavy-ion fusion reactions can be estimated simply using the ''Optimum Energy Rule'' proposed by Swiatecki, Siwek-Wilczynska, and Wilczynski.

  15. X-ray and Raman spectroscopic studies on Ru substituted LiMn{sub 2}O{sub 4}

    SciTech Connect (OSTI)

    Kalavathi, S.; Ravindran, T. R.; Sahu, P. Ch.; Kalaivani, D.

    2015-06-24

    Phase pure Ru substituted LiMn{sub 2}O{sub 4} charge frustrated spinel compounds have been synthesized. Ru substitution for Mn is possible only up to 7.5%. Powder diffraction measurements confirm sustenance of charge frustrated cubic phase with space group Fd3m upon substitution of Ru for Mn. An increase in lattice parameter has been observed indicating replacement of Mn as Ru{sup 3+} or Ru{sup 4+} rather than Ru{sup 5+}. Raman spectroscopic measurements show that the crystal structure is robust against an increase of laser power and the observed bands show an expected red shift. In the case of Ru substituted LiMn{sub 2}O{sub 4}, the A{sub 1g} symmetric stretching mode, the F{sup (1)}{sub 2g} and the F{sup (2)}{sub 2g} symmetric bending modes identified with the Mn-O octahedra show a red shift up to Ru 0.075 and at higher Ru concentrations, revert back to the frequency corresponding to the pristine LiMn{sub 2}O{sub 4}.

  16. 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.

  17. Soft Landing of Bare PtRu Nanoparticles for Electrochemical Reduction of Oxygen

    SciTech Connect (OSTI)

    Johnson, Grant E.; Colby, Robert J.; Engelhard, Mark H.; Moon, DaeWon; Laskin, Julia

    2015-08-07

    Magnetron sputtering of two independent Pt and Ru targets coupled with inert gas aggregation in a modified commercial source has been combined with soft landing of mass-selected ions to prepare bare 4.5 nm diameter PtRu alloy nanoparticles on glassy carbon electrodes with controlled size and morphology for electrochemical reduction of oxygen in solution. Employing atomic force microscopy (AFM) it is shown that the nanoparticles bind randomly to the glassy carbon electrode at a relatively low coverage of 7 x 104 ions µm-2 and that their average height is centered at 4 nm. Scanning transmission electron microscopy images obtained in the high-angle annular dark field mode (STEM-HAADF) further confirm that the soft-landed PtRu alloy nanoparticles are uniform in size and have a Ru core decorated with small regions of Pt on the surface. Wide-area scans of the electrodes using X-ray photoelectron spectroscopy (XPS) reveal the presence of both Pt and Ru in relative atomic concentrations of ~9% and ~33%, respectively. Deconvolution of the high energy resolution XPS spectra in the Pt4f and Ru3d regions indicates the presence of both oxidized Pt and Ru. The substantially higher loading of Ru compared to Pt and enrichment of Pt at the surface of the alloy nanoparticles is confirmed by wide-area analysis of the electrodes using time-of-flight medium energy ion scattering (TOF-MEIS) employing both 80 keV He+ and O+ ions. The activity of electrodes containing 7 x 104 ions µm-2 of bare 4.5 nm PtRu nanoparticles toward the electrochemical reduction of oxygen was evaluated employing cyclic voltammetry (CV) in 0.1 M HClO4 and 0.5 M H2SO4 solutions. In both electrolytes a pronounced reduction peak was observed during O2 purging of the solution that was not evident during purging with Ar. Repeated electrochemical cycling of the electrodes revealed little evolution in the shape or position of the voltammograms indicating high stability of the alloy nanoparticles supported on glassy

  18. Influence of Electron Doping on Magnetic Order in CeRu2Al10

    SciTech Connect (OSTI)

    Kobayashi, Riki; Kaneko, Koji; Saito, Kotaro; Mignot, Jean-Michel; Andre, Gilles; Robert, Julien; Wakimoto, Shuichi; Matsuda, Masaaki; Chi, Songxue; Haga, Yoshinori; Matsuda, Tatsuma; Yamamoto, Etsuji; Nishioka, Takashi; Tanida, Hiroshi; Sera, Masafumi

    2014-01-01

    The effect of electron doping by the substitution of Rh for Ru on unconventional magnetic order in CeRu2Al10 was investigated via neutron powder diffraction. In Ce(Ru1 xRhx)2Al10 with x = 0.05, 0.12, and 0.2, reorientation of the ordered moment from the c-axis as in pure CeRu2Al10 to the a-axis takes place in all samples, while the ordering vector q 0; 1; 0 remains unchanged within this concentration range. The moment reorientation is accompanied by an increase in its size by a factor of 2.4, from = 0.43 B at x = 0 to = 1.06, 1.04, and 1.02 B for x = 0.05, 0.12, and 0.2, respectively. The continuous decrease in the N el temperature T0(TN), despite an abrupt increase in , underlines the strong anisotropy in the exchange interaction in CeRu2Al10 and the fact that this anisotropy is easily suppressed by electron doping. 1.

  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. Catalytic Ionic Hydrogenation of Ketones by {[Cp*Ru(CO)2]2(? H)}+

    SciTech Connect (OSTI)

    Fagan, Paul J.; Voges, Mark H.; Bullock, R. Morris

    2010-02-22

    {[Cp*Ru(CO)2]2(? H)}+OTf functions as a homogeneous catalyst precursor for hydrogenation of ketones to alcohols, with hydrogenations at 1 mol % catalyst loading at 90 C under H2 (820 psi) proceeding to completion and providing >90% yields. Hydrogenation of methyl levulinate generates ?-valerolactone, presumably by ring-closing of the initially formed alcohol with the methyl ester. Experiments in neat Et2C=O show that the catalyst loading can be <0.1 mole %, and that at least 1200 turnovers of the catalyst can be obtained. These reactions are proposed to proceed by an ionic hydrogenation pathway, with the highly acidic dihydrogen complex [Cp*Ru(CO)2(?2-H2)]+OTf- being formed under the reaction conditions from reaction of H2 with {[Cp*Ru(CO)2]2(? H)}+OTf .

  1. miniFE

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

    miniFE miniFE Description FE is a Finite Element mini-application which implements a couple of kernels representative of implicit finite-element applications. It assembles a sparse linear-system from the steady-state conduction equation on a brick-shaped problem domain of linear 8-node hex elements. It then solves the linear-system using a simple un-preconditioned conjugate-gradient algorithm. Thus the kernels that it contains are: computation of element-operators (diffusion matrix, source

  2. Ferromagnetic Kondo lattice CeRuSi{sub 2} with non-Fermi-liquid behavior

    SciTech Connect (OSTI)

    Nikiforov, V. N.; Baran, M.; Irkhin, V. Yu.

    2013-05-15

    The structure, electronic, thermodynamic, and magnetic properties of the CeRuSi{sub 2} Kondo lattice with ferromagnetic ordering characterized by a small moment of the ground state are investigated. Anomalies in the temperature dependences of heat capacity and resistivity (unusual power or logarithmic behavior) observed in the low-temperature range indicate a non-Fermi-liquid behavior. The results are compared with those for other Ce{sub l}Ru{sub n}X{sub m} compounds and anomalous systems based on rare-earth elements and actinides that had been studied earlier.

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

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

    RU N INDIANA LAKESHORE RUN E LUMBER CIT Y WARSAW JOHNST OWN BU RNSIDE MILLSTONE FROSTBUR G JUN EAU PLU MVILLE CHERRY HILL KAN E BOSWELL MAR ION CENT ER CREEKSIDE SALTSBUR G POINT N BLAIR SVILL E COU NCIL RU N SIGEL LEWISVILLE BEAR C REEK AR MBRUST OHIOPYLE HALLT ON BR OOKVILLE MAR KTON NOL O RAT HMEL COR SICA MAR CHAND SMIC KSBU RG HOWE APOLLO SEVEN SPRIN GS YAT ESBORO MCNEES LUCIND A GEORGE PIN EY LEEPER TIMBLIN WILL ET FERGUSON CLIMAX PANIC DAVY HILL TIDIOUT E GRAMPIAN SLIGO ROC KVI LLE

  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. 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.

  7. 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.

  8. Fe(A)

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

    Fe(A) Fe(B) O ( 0 0 1 ) ( 0 1 0 ) ( 1 0 0 ) (001) (010) Fe(A) layer Fe(B) layer (100) Surface R eac2vity o f I ron O xide G. S . P arkinson 1 *, Z . N ovotny 1 , P . J acobson 1 , T . M anz 2 , D . S . S holl 2 , F . N . W omack 3 , P . T . S prunger 3 a nd U . D iebold 1* 1 Ins2tute o f A pplied P hysics, V ienna U niversity o f T echnology, V ienna, A ustria 2 Georgia I ns2tute o f T echnology, A tlanta, G A 3 0332 U SA 3 Louisiana S tate U niversity, B aton R ouge, L A 7 0803 U SA

  9. Getting to Santa Fe

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

    with Road Runner for 65 + tax they will also take two passengers The Capital City Cab (Santa Fe taxi company) - 50 each way. Reservation not required Hertz car rental (LANL...

  10. 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.

  11. Electric transport through nanometric CoFe{sub 2}O{sub 4} thin films investigated by conducting atomic force microscopy

    SciTech Connect (OSTI)

    Foerster, M.; Gutierrez, D. F.; Rigato, F.; Fontcuberta, J.; Rebled, J. M.; Peiro, F.

    2012-01-01

    A systematic study of electric transport through thin (2-8 nm) CoFe{sub 2}O{sub 4} films deposited on epitaxial SrRuO{sub 3} bottom electrodes was performed by conducting atomic force microscopy (CAFM). Experimental procedures to investigate transport through thin insulating films by CAFM are critically revised, and the potential of CoFe{sub 2}O{sub 4} films for the use as spin-filtering barriers is assessed. It is concluded that, at room-temperature, a non-tunnel channel significantly contributes to the electric transport, thus limiting the spin-filtering efficiency.

  12. 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.

  13. 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.

  14. 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.

  15. Magnetic anisotropy and other studies in amorphous Tb-Fe films

    SciTech Connect (OSTI)

    Krishman, R.; Porte, M.; Tessier, M.; Vitton, J.P.; LeCars, Y.

    1988-03-01

    The authors report their investigations of magnetic properties on RF sputtered Tb/sub x/Fe/sub 1-x/ films with 13 < x 32 < at%. The samples had protective layer of Al/sub 2/O/sub 3/ about 15 nm thick. B-H and Kerr loops were studied. Torque measurements were made in the temperature range 20-300K with a maximum applied field of 12.5 kOe. The authors data as regards, M, H/sub c/, upsilon/sub k/ and K/sub u/ are in general agreement with published data. Perfect rectangular loops were obtained for 20 < x < 32. Torque curves show large rotational hysteresis. For Tb/sub 26/Fe/sub 74/, K/sub u/ increases rapidly as T is lowered and below 80K measurements are no longer possible due to lack of magnetic saturation. For Tb/sub 20/Fe/sub 80/, with a T/sub comp/ approx. = 150K, torque curves show anomaly in the neighbourhood of T/sub comp/. the results are discussed leading the the conclusion that stress effects have a dominant role to modify K/sub u/ particularly at low T. Tb moment at 4K is calculated to be 7.3 +- 0.6 ..mu../sub BETA/ assuming a Fe moment of 1.7..mu../sub BETA/.

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

    SciTech Connect (OSTI)

    Matheu, Roc; Francs, 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)(NN2)2]3+, 23+ (NN22+ 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 counterpart 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 s1 and TONs >45000. The observed performance is comparable to the best electrocatalysts reported so far, at neutral pH.

  17. 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.

  18. Influence of Electron Doping on Magnetic Order in CeRu2Al10

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

    Kobayashi, Riki; Kaneko, Koji; Saito, Kotaro; Mignot, Jean-Michel; André, Gilles; Robert, Julien; Wakimoto, Shuichi; Matsuda, Masaaki; Chi, Songxue; Haga, Yoshinori; et al

    2014-09-17

    The effect of electron doping by the substitution of Rh for Ru on unconventional magnetic order in CeRu2Al10 was investigated via neutron powder diffraction. In Ce(Ru1-xRhx)2Al10 with x = 0.05, 0.12, and 0.2, reorientation of the ordered moment from the c- to the a-axis takes place in all samples, while the ordering vector q=(0 1 0) remains unchanged within this concentration range. The moment reorientation is accompanied by an enhancement in its size by a factor of ~2.4, from μ=0.43 μB at x=0 to μ =1.06, 1.04, and 1.02 μB for x=0.05, 0.12 and 0.2, respectively. The continuous decrease inmore » N´eel temperature T0(TN), despite an abrupt increase in μ , underlines the strong anisotropy in the exchange interaction in CeRu2Al10, and the fact that this anisotropy is easily suppressed by electron doping.« less

  19. Electrocatalytic Reduction of Carbon Dioxide with a Well-Defined PN 3 -Ru Pincer Complex

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

    Min, Shixiong; Rasul, Shahid; Li, Huaifeng; Grills, David C.; Takanabe, Kazuhiro; Li, Lain-Jong; Huang, Kuo-Wei

    2015-11-13

    We established a well-defined PN3-Ru pincer complex (5) bearing a redox-active bipyridine ligand with an aminophosphine arm as an effective and stable molecular electrocatalyst for CO2 reduction to CO and HCOOH with negligible formation of H2 in a H2O/MeCN mixture.

  20. 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

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

    SciTech Connect (OSTI)

    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 counterpart 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.

  2. Theoretical calculations for structural, elastic, and thermodynamic properties of RuN{sub 2} under high pressure

    SciTech Connect (OSTI)

    Dong, Bing; Zhou, Xiao-Lin E-mail: lkworld@126.com; Chang, Jing; Liu, Ke E-mail: lkworld@126.com

    2014-08-07

    The structural and elastic properties of RuN{sub 2} were investigated through the first-principles calculation using generalized gradient approximation (GGA) and local density approximation (LDA) within the plane-wave pseudopotential density functional theory. The obtained equilibrium structure and mechanical properties are in excellent agreement with other theoretical results. Then we compared the elastic modulus of RuN{sub 2} with several other isomorphic noble metal nitrides. Results show that RuN{sub 2} can nearly rival with OsN{sub 2} and IrN{sub 2}, which indicate RuN{sub 2} is a potentially ultra-incompressible and hard material. By the elastic stability criteria, it is predicted that RuN{sub 2} is stable in our calculations (0–100 GPa). The calculated B/G ratios indicate that RuN{sub 2} possesses brittle nature at 0 GPa and when the pressure increases to 13.4 GPa (for LDA) or 20.8 GPa (for GGA), it begins to prone to ductility. Through the quasi-harmonic Debye model, we also investigated the thermodynamic properties of RuN{sub 2}.

  3. Biomimetic model for [FeFe]-hydrogenase: Asymmetrically disubstituted

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

    diiron complex with a redox-active 2,2'-bipyridyl ligand Biomimetic model for [FeFe]-hydrogenase: Asymmetrically disubstituted diiron complex with a redox-active 2,2'-bipyridyl ligand Authors: Roy, S., Groy, T., Jones, A.K. Title: Biomimetic model for [FeFe]-hydrogenase: Asymmetrically disubstituted diiron complex with a redox-active 2,2'-bipyridyl ligand Source: Dalton Transactions Year: 2013 Volume: 42 Pages: 3843-3853 ABSTRACT: [FeFe]-hydrogenases feature a unique active site in which the

  4. Theoretical Investigations on the Formation and Dehydrogenation Reaction Pathways of H(NH2BH2)nH (n=1-4) Oligomers: Importance of Dihydrogen Interactions (DHI)

    SciTech Connect (OSTI)

    Li, Jun; Kathmann, Shawn M.; Hu, Han-Shi; Schenter, Gregory K.; Autrey, Thomas; Gutowski, Maciej S.

    2010-09-06

    The H(NH2BH2)nH oligomers are possible products from dehydrogenation of ammonia borane (NH3BH3) and ammonium borohydride (NH4BH4), which belong to a class of boron-nitrogen-hydrogen (BNHx) compounds that are promising materials for chemical hydrogen storage. Understanding the kinetics and reaction pathways of formation of these oligomers and their further dehydrogenation is essential for developing BNHx-based hydrogen storage materials. We have performed computational modeling using density functional theory (DFT), ab initio wavefunction theory, and Car-Parrinello molecular dynamics (CPMD) simulations on the energetics and formation pathways for the H(NH2BH2)nH (n=1-4) oligomers, polyaminoborane (PAB), from NH3BH3 monomers and the subsequent dehydrogenation steps to form polyiminoborane (PIB). Through transition state searches and evaluation of the intrinsic reaction coordinates, we have investigated the B-N bond cleavage, the reactions of NH3BH3 molecule with intermediates, dihydrogen release through intra- and intermolecular hydrogen transfer, dehydrocoupling/cyclization of the oligomers, and the dimerization of NH3BH3 molecules. We discovered the formation mechanism of H(NH2BH2)n+1H oligomers through reactions of the H(NH2BH2)nH oligomers first with BH3 followed by reactions with NH3 and the release of H2, where the BH3 and NH3 intermediates are formed through dissociation of NH3BH3. We also found that the dimerization of the NH3BH3 molecules to form c-(NH2BH2)2 is slightly exothermic, with an unexpected transition state that leads to the simultaneous release of two H2 molecules. The dehydrogenations of the oligomers are also exothermic, typically by less than 10 kcal/(mol of H2), with the largest exothermicity for n=3. The transition state search shows that the one-step direct dehydrocoupling cyclization of the oligomers is not a favored pathway because of high activation barriers. The dihydrogen bonding, in which protic (HN) hydrogens interact with hydridic

  5. Microsoft Word - spintronics bh

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

    across Borders Spintronics is a field that keeps both scientists and engineers excited from a fundamental physics and applications perspective. But what is "spintronics" exactly? ...

  6. Microsoft Word - Pili bh

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

    Figure legend: Models of the Type V pilins and pilus. (Left) Schematic representations of individual mature pilins at different locations of a pilus (tip, body, and base) and their assembly via a strand- exchange mechanism. (Right) A molecular model of a segment of the type V pilus filament consisting of multiple pilins. A New Type of Pilus from the Human Microbiome Pili (or fimbriae) are hair-like structures on the cell surface of many bacteria. Pili can play a variety of functions in

  7. Microsoft Word - RRAM bh

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

    April 2016 Figure 1. Depiction of focused x-rays used to study a crossbar tantalum oxide memristor device in-operando as it was switched between information states of 0's and 1's using voltage pulses. The resultant radial oxygen migration profile mapped using O K-edge x-rays, along with the spectral differences between the oxygen- rich and oxygen-deficient regions. Observing Oxygen Atoms Move during Information Storage in Tantalum Oxide Memristors Memristor technology, or resistive random access

  8. Microsoft Word - Agcontact bh

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

    April 2016 X-ray Study Reveals How Silver-to-Silicon Contacts Form for Solar Cells Solar energy must be one of the primary energy sources as society transitions away from a predominantly fossil fuels based economy. Currently, the overwhelming majority (>90%) of the photovoltaic (PV) market consists of silicon solar cells. While relatively inexpensive, this technology depends predominately on a screen-printed silver electrical front-contact and the formation of this contact uses a lead-based

  9. The nature and role of bridged carbonyl intermediates in theultrafast photo-induced rearrangement of Ru3(CO)12.

    SciTech Connect (OSTI)

    Glascoe, Elizabeth A.; Kling, Matthias F.; Shanoski, Jennifer E.; Harris, Charles B.

    2005-09-18

    The photochemistry of the trimetal cluster,Ru(3)(CO)12, was investigated on the ultrafast timescale using UV-vis pump, infrared probe spectroscopy in order to study the transient intermediates formed upon photoexcitation.

  10. 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.

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

    SciTech Connect (OSTI)

    Karao?lu, E.; zel, U.; Caner, C.; Baykal, A.; Summak, M.M.; Szeri, 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, UVVis 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 9993% and 9893%, 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.

  12. 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, Frdric; 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.

  13. BH{sub 2} revisited: New, extensive measurements of laser-induced fluorescence transitions and ab initio calculations of near-spectroscopic accuracy

    SciTech Connect (OSTI)

    Sunahori, Fumie X.; Gharaibeh, Mohammed; Clouthier, Dennis J.; Tarroni, Riccardo

    2015-05-07

    The spectroscopy of gas phase BH{sub 2} has not been explored experimentally since the pioneering study of Herzberg and Johns in 1967. In the present work, laser-induced fluorescence (LIF) spectra of the A{sup ~} {sup 2}B{sub 1}(Π{sub u})−X{sup ~2}A{sub 1} band system of {sup 11}BH{sub 2}, {sup 10}BH{sub 2}, {sup 11}BD{sub 2}, and {sup 10}BD{sub 2} have been observed for the first time. The free radicals were “synthesized” by an electric discharge through a precursor mixture of 0.5% diborane (B{sub 2}H{sub 6} or B{sub 2}D{sub 6}) in high pressure argon at the exit of a pulsed valve. A total of 67 LIF bands have been measured and rotationally analyzed, 62 of them previously unobserved. These include transitions to a wide variety of excited state bending levels, to several stretch-bend combination levels, and to three ground state levels which gain intensity through Renner-Teller coupling to nearby excited state levels. As an aid to vibronic assignment of the spectra, very high level hybrid ab initio potential energy surfaces were built starting from the coupled cluster singles and doubles with perturbative triples (CCSD(T))/aug-cc-pV5Z level of theory for this seven-electron system. In an effort to obtain the highest possible accuracy, the potentials were corrected for core correlation, extrapolation to the complete basis set limit, electron correlation beyond CCSD(T), and diagonal Born-Oppenheimer effects. The spin-rovibronic states of the various isotopologues of BH{sub 2} were calculated for energies up to 22 000 cm{sup −1} above the X{sup ~} (000) level without any empirical adjustment of the potentials or fitting to experimental data. The agreement with the new LIF data is excellent, approaching near-spectroscopic accuracy (a few cm{sup −1}) and has allowed us to understand the complicated spin-rovibronic energy level structure even in the region of strong Renner-Teller resonances.

  14. 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.

  15. 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.

  16. 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.}

  17. Correlation between microstructure and thermionic electron emission from Os-Ru thin films on dispenser cathodes

    SciTech Connect (OSTI)

    Swartzentruber, Phillip D.; John Balk, Thomas; Effgen, Michael P.

    2014-07-01

    Osmium-ruthenium films with different microstructures were deposited onto dispenser cathodes and subjected to 1000 h of close-spaced diode testing. Tailored microstructures were achieved by applying substrate biasing during deposition, and these were evaluated with scanning electron microscopy, x-ray diffraction, and energy dispersive x-ray spectroscopy before and after close-spaced diode testing. Knee temperatures determined from the close-spaced diode test data were used to evaluate cathode performance. Cathodes with a large (10-11) Os-Ru film texture possessed comparatively low knee temperatures. Furthermore, a low knee temperature correlated with a low effective work function as calculated from the close-spaced diode data. It is proposed that the formation of strong (10-11) texture is responsible for the superior performance of the cathode with a multilayered Os-Ru coating.

  18. 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.}

  19. 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.

  20. Catalytic Ionic Hydrogenation of Ketones by {[Cp*Ru(CO)2]2(-H)}+

    SciTech Connect (OSTI)

    Bullock, R.M.; Fagan, P.J.; Voges, M.H.

    2010-02-22

    {l_brace}[Cp*Ru(CO){sub 2}]{sub 2}({mu}-H){r_brace}{sup +}OTf{sup -} functions as a homogeneous catalyst precursor for hydrogenation of ketones to alcohols, with hydrogenations at 1 mol % catalyst loading at 90 C under H{sub 2} (820 psi) proceeding to completion and providing >90% yields. Hydrogenation of methyl levulinate generates {gamma}-valerolactone, presumably by ring-closing of the initially formed alcohol with the methyl ester. Experiments in neat Et{sub 2}C=O show that the catalyst loading can be <0.1 mol % and that at least 1200 turnovers of the catalyst can be obtained. These reactions are proposed to proceed by an ionic hydrogenation pathway, with the highly acidic dihydrogen complex [Cp*Ru(CO){sub 2}({eta}{sup 2}-H{sub 2})]{sup +}OTf{sup -} being formed under the reaction conditions from reaction of H2 with {l_brace}[Cp*Ru(CO){sub 2}]{sub 2}({mu}-H){r_brace}{sup +}OTf{sup -}.

  1. 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.

  2. Surfactant-thermal method to synthesize a new Zn(II)-trimesic MOF with confined Ru(bpy){sub 3}{sup 2+} complex

    SciTech Connect (OSTI)

    Xu, Hui; Gao, Junkuo; Wang, Jiangpeng; Qian, Xuefeng; Song, Ruijing; Cui, Yuanjing; Yang, Yu; Qian, Guodong

    2015-03-15

    A surfactant-thermal method was used to prepare a new zinc-1,3,5-benzentricarboxylate-based metal-organic framework (ZJU-100) with confined Ru(bpy){sub 3}{sup 2+} (RuBpy) complex by using surfactant PEG 400 as reaction medium. The RuBpy molecules were encapsulated between the 2-D sheets in ZJU-100. ZJU-100 showed bathochromic shift in the steady-state emission spectrum and increased emission lifetimes relative to RuBpy molecules. The extended lifetime is attributed to the reduced nonradiative decay rate due to the stabilization of RuBpy within the rigid MOF framework. These results represent the first example of MOF with confined complex synthesized by surfactant, indicating that the surfactant-thermal method could offer exciting opportunities for preparing new MOFs host/guest materials with novel structures and interesting luminescent properties. - Graphical abstract: A surfactant-thermal method was used to prepare a new zinc-1,3,5-benzentricarboxylate-based metal-organic framework (ZJU-100) with confined Ru(bpy){sub 3}{sup 2+} (RuBpy) complex by using surfactant PEG 400 as reaction medium. - Highlights: • Surfactant-thermal synthesis of crystalline metal-organic framework host/guest materials. • RuBpy molecules were encapsulated between the 2-D sheets of MOFs. • Extended lifetime is observed due to the stabilization of RuBpy within the rigid MOF framework.

  3. High antiferromagnetic transition temperature of a honeycomb compound SrRu2O6

    SciTech Connect (OSTI)

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

    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) 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 .

  4. Santa Fe, NM 87506

    Office of Environmental Management (EM)

    July 31, 2014 Ms. Kimberly Davis Lebak Manager Los Alamos Field Office 3747 West Jemez Road, MS A316 Los Alamos, NM 87544 Mr. Pete Maggiore Assistant Manager for Environmental Operations 3747 West Jemez Road, MS A316 Los Alamos, NM 87544 Dear Ms. Lebak and Mr. Maggiore, I am pleased to enclose Recommendation 2014-02, unanimously approved by the Northern New Mexico Citizens' Advisory Board at its July 30 th meeting in Santa Fe. Please call Lee Bishop, DDFO or Menice Santistevan, Executive

  5. 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 = 80400 K and N{sub A}{sup Ru} ? 9.5 10{sup 19}?5.7 10{sup 20} cm{sup ?3} (x = 00.03), 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.

  6. Ru{sub 2}Ge{sub 3}: Crystal growth and some properties

    SciTech Connect (OSTI)

    Borshchevsky, A.; Fleurial, J.P.

    1993-10-01

    Large samples of Ru{sub 2}Ge{sub 3} were grown from Ge-rich off-stoichiometric melts at a temperature close to 1,460 C by a vertical gradient freeze method in graphite and glassy carbon crucibles. Diffusionless transition from high temperature tetragonal structure to low temperature orthorhombic structure causes twinning and crack formation. Thermal expansion coefficients of both low and high temperature phases were measured. Some electrical transport properties in the 25--1,000 C temperature range in different crystallographic directions are also described for this high temperature semiconductor. Substantial anisotropy is observed.

  7. Observation of large magnetocaloric effect in HoRu{sub 2}Si{sub 2}

    SciTech Connect (OSTI)

    Paramanik, Tapas Das, Kalipada; Das, I.

    2014-02-28

    Detailed magnetic, magnetotransport, and magnetocaloric measurements on HoRu{sub 2}Si{sub 2} have been performed. In this Letter, we report presence of spin reorientation transition below paramagnetic to antiferromagnetic transition temperature (T{sub N} = 19 K). Large magnetic entropy change 9.1 J/kg K and large negative magnetoresistance ∼21% in a magnetic field of 5 T has been observed around T{sub N}, which is associated with field induced spin-flip metamagnetic transition.

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

    SciTech Connect (OSTI)

    Aczel, Adam A; Bugaris, Dan; Yeon, Jeongho; Dela Cruz, Clarina R; Zur Loye, Hans-Conrad; Nagler, Stephen E

    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.

  9. 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.

  10. Santa Fe Jets and Heavy Flavor Workshop

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

    Santa Fe Jets and Heavy Flavor Workshop Santa Fe Jets and Heavy Flavor Workshop WHEN: Jan 11, 2016 8:30 AM - Jan 13, 2016 5:30 PM WHERE: Inn and Spa at Loretto 211 Old Santa Fe...

  11. 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.

  12. 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.; Ma, C. R.; Liu, M.; Collins, G.; Zhang, Y. M.; Chen, C. L.

    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.

  13. 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.

  14. 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.

  15. FE Clean Energy Group | Open Energy Information

    Open Energy Info (EERE)

    FE Clean Energy Group Jump to: navigation, search Name: FE Clean Energy Group Place: Darien, Connecticut Zip: 6820 Sector: Efficiency Product: A Private Equity Fund Manager which...

  16. FE Categorical Exclusions | Department of Energy

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

    FE Categorical Exclusions FE Categorical Exclusions RSS June 4, 2014 CX-011993: Categorical Exclusion Determination Cheniere Marketing, LLC CX(s) Applied: B5.7 Date: 06042014...

  17. Influence of Electron Doping on Magnetic Order in CeRu2Al10

    SciTech Connect (OSTI)

    Kobayashi, Riki; Kaneko, Koji; Saito, Kotaro; Mignot, Jean-Michel; André, Gilles; Robert, Julien; Wakimoto, Shuichi; Matsuda, Masaaki; Chi, Songxue; Haga, Yoshinori; Matsuda, Tatsuma D.; Yamamoto, Etsuji; Nishioka, Takashi; Matsumura, Masahiro; Tanida, Hiroshi; Sera, Masafumi

    2014-09-17

    The effect of electron doping by the substitution of Rh for Ru on unconventional magnetic order in CeRu2Al10 was investigated via neutron powder diffraction. In Ce(Ru1-xRhx)2Al10 with x = 0.05, 0.12, and 0.2, reorientation of the ordered moment from the c- to the a-axis takes place in all samples, while the ordering vector q=(0 1 0) remains unchanged within this concentration range. The moment reorientation is accompanied by an enhancement in its size by a factor of ~2.4, from μ=0.43 μB at x=0 to μ =1.06, 1.04, and 1.02 μB for x=0.05, 0.12 and 0.2, respectively. The continuous decrease in N´eel temperature T0(TN), despite an abrupt increase in μ , underlines the strong anisotropy in the exchange interaction in CeRu2Al10, and the fact that this anisotropy is easily suppressed by electron doping.

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

    SciTech Connect (OSTI)

    Belau, Leonid; Park, Jeong Y.; Liang, Ted; Seo, Hyungtak; Somorjai, Gabor A.

    2009-04-10

    The authors report the chemical influence of cleaning of the Ru capping layer on the extreme ultraviolet (EUV) reflector surface. The cleaning of EUV reflector to remove the contamination particles has two requirements: to prevent corrosion and etching of the reflector surface and to maintain the reflectivity functionality of the reflector after the corrosive cleaning processes. Two main approaches for EUV reflector cleaning, wet chemical treatments [sulfuric acid and hydrogen peroxide mixture (SPM), ozonated water, and ozonated hydrogen peroxide] and dry cleaning (oxygen plasma and UV/ozone treatment), were tested. The changes in surface morphology and roughness were characterized using scanning electron microscopy and atomic force microscopy, while the surface etching and change of oxidation states were probed with x-ray photoelectron spectroscopy. Significant surface oxidation of the Ru capping layer was observed after oxygen plasma and UV/ozone treatment, while the oxidation is unnoticeable after SPM treatment. Based on these surface studies, the authors found that SPM treatment exhibits the minimal corrosive interactions with Ru capping layer. They address the molecular mechanism of corrosive gas and liquid-phase chemical interaction with the surface of Ru capping layer on the EUV reflector.

  19. FE Blog | Department of Energy

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

    implement the change. August 5, 2014 FE's Christopher Smith spoke recently during the Africa Leaders' Visit: Energy event in Houston. During the three-day event organized by the...

  20. FE Blog | Department of Energy

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

    with senior executives in the Office of Fossil Energy (FE). In this edition we talk to Paula Gant, Deputy Secretary for Oil and Gas August 17, 2015 Profiles in Leadership:...

  1. 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.

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

    SciTech Connect (OSTI)

    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-κ-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 Ru 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

  3. Microsoft Word - FeMoco.doc

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

    Fig. 1. Fourier transforms calculated over the k-range 2-16 Å -1 of EXAFS data (dotted) and fits (solid) from (left) MoFe protein- bound FeMoco and (right) the NifEN-bound FeMoco precursor. The EXAFS data were obtained, respectively, by subtraction of ΔnifB MoFe protein EXAFS from wild-type MoFe protein EXAFS and ΔnifB NifEN EXAFS from NifEN EXAFS. The insets show the structure of FeMoco (left) and a structural model consistent with the XAS analysis of the NifEN-bound FeMoco precursor

  4. Understanding the Electronic Structure of 4d Metal Complexes: From Molecular Spinors to L-Edge Spectra of a di-Ru Catalyst

    SciTech Connect (OSTI)

    Alperovich, Igor; Smolentsev, Grigory; Moonshiram, Dooshaye; Jurss, Jonah W.; Concepcion, Javier J.; Meyer, Thomas J.; Soldatov, Alexander; Pushkar, Yulia

    2015-09-17

    L{sub 2,3}-edge X-ray absorption spectroscopy (XAS) has demonstrated unique capabilities for the analysis of the electronic structure of di-Ru complexes such as the blue dimer cis,cis-[Ru{sub 2}{sup III}O(H{sub 2}O){sub 2}(bpy){sub 4}]{sup 4+} water oxidation catalyst. Spectra of the blue dimer and the monomeric [Ru(NH{sub 3}){sub 6}]{sup 3+} model complex show considerably different splitting of the Ru L{sub 2,3} absorption edge, which reflects changes in the relative energies of the Ru 4d orbitals caused by hybridization with a bridging ligand and spin-orbit coupling effects. To aid the interpretation of spectroscopic data, we developed a new approach, which computes L{sub 2,3}-edges XAS spectra as dipole transitions between molecular spinors of 4d transition metal complexes. This allows for careful inclusion of the spin-orbit coupling effects and the hybridization of the Ru 4d and ligand orbitals. The obtained theoretical Ru L{sub 2,3}-edge spectra are in close agreement with experiment. Critically, existing single-electron methods (FEFF, FDMNES) broadly used to simulate XAS could not reproduce the experimental Ru L-edge spectra for the [Ru(NH{sub 3}){sub 6}]{sup 3+} model complex nor for the blue dimer, while charge transfer multiplet (CTM) calculations were not applicable due to the complexity and low symmetry of the blue dimer water oxidation catalyst. We demonstrated that L-edge spectroscopy is informative for analysis of bridging metal complexes. The developed computational approach enhances L-edge spectroscopy as a tool for analysis of the electronic structures of complexes, materials, catalysts, and reactive intermediates with 4d transition metals.

  5. Probing the transition state region in catalytic CO oxidation on Ru

    SciTech Connect (OSTI)

    Ostrom, H.; Oberg, H.; Xin, H.; LaRue, J.; Beye, M.; Dell'Angela, M.; Gladh, J.; Ng, M. L.; Sellberg, J. A.; Kaya, S.; Mercurio, G.; Nordlund, D.; Hantschmann, M.; Hieke, F.; Kuhn, D.; Schlotter, W. F.; Dakovski, G. L.; Turner, J. J.; Minitti, M. P.; Mitra, A.; Moeller, S. P.; Fohlisch, A.; Wolf, M.; Wurth, W.; Persson, M.; Norskov, J. K.; Abild-Pedersen, F.; Ogasawara, H.; Pettersson, L. G. M.; Nilsson, A.

    2015-02-12

    Femtosecond x-ray laser pulses are used to probe the CO oxidation reaction on ruthenium (Ru) initiated by an optical laser pulse. On a time scale of a few hundred femtoseconds, the optical laser pulse excites motions of CO and O on the surface, allowing the reactants to collide, and, with a transient close to a picosecond (ps), new electronic states appear in the O K-edge x-ray absorption spectrum. Density functional theory calculations indicate that these result from changes in the adsorption site and bond formation between CO and O with a distribution of OC–O bond lengths close to the transition state (TS). After 1 ps, 10% of the CO populate the TS region, which is consistent with predictions based on a quantum oscillator model.

  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 SrRuO₃ films, deposited epitaxially on TiO₂-terminated SrTiO₃ (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; 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 variablemorerange 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

  8. 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

  9. Low-temperature crystal and magnetic structure of α – RuCl3

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

    Cao, Huibo B.; Yan, Jiaqiang; Bridges, Craig A.; Lumsden, Mark D.; Mandrus, D. G.; Chakoumakos, Bryan C.; Nagler, Stephen E.; Banerjee, A.; Tennant, D. A.

    2016-04-19

    Here, single crystals of the Kitaev spin-liquid candidate α – RuCl3 have been studied to determine the low-temperature bulk properties, the structure, and the magnetic ground state. Refinements of x-ray diffraction data show that the low-temperature crystal structure is described by space group C2/m with a nearly perfect honeycomb lattice exhibiting less than 0.2% in-plane distortion. The as-grown single crystals exhibit only one sharp magnetic transition at TN = 7 K. The magnetic order below this temperature exhibits a propagation vector of k=(0,1,1/3), which coincides with a three-layer stacking of the C2/m unit cells. Magnetic transitions at higher temperatures upmore » to 14 K can be introduced by deformations of the crystal that result in regions in the crystal with a two-layer stacking sequence. The best-fit symmetry-allowed magnetic structure of the as-grown crystals shows that the spins lie in the ac plane, with a zigzag configuration in each honeycomb layer. The three-layer repeat out-of-plane structure can be refined as a 120° spiral order or a collinear structure with a spin direction of 35° away from the a axis. The collinear spin configuration yields a slightly better fit and also is physically preferred. The average ordered moment in either structure is less than 0.45(5) μB per Ru3+ ion.« less

  10. Application of Gene-Shuffling for the Rapid Generation of Novel [FeFe]-Hydrogenase Libraries

    SciTech Connect (OSTI)

    Nagy, L. E.; Meuser, J. E.; Plummer, S.; Seibert, M.; Ghirardi, M. L.; King, P. W.; Ahmann, D.; Posewitz, M. C.

    2007-01-01

    A gene-shuffling technique was identified, optimized and used to generate diverse libraries of recombinant [FeFe]-hydrogenases. Six native [FeFe]-hydrogenase genes from species of Clostridia were first cloned and separately expressed in Escherichia coli concomitantly with the assembly proteins required for [FeFe]-hydrogenase maturation. All enzymes, with the exception of C. thermocellum HydA, exhibited significant activity when expressed. Single-stranded DNA fragments from genes encoding the two most active [FeFe]-hydrogenases were used to optimize a gene-shuffling protocol and generate recombinant enzyme libraries. Random sampling demonstrates that several shuffled products are active. This represents the first successful application of gene-shuffling using hydrogenases. Moreover, we demonstrate that a single set of [FeFe]-hydrogenase maturation proteins is sufficient for the heterologous assembly of the bioinorganic active site of several native and shuffled [FeFe]-hydrogenases.

  11. Fischer-Tropsch Synthesis: Assessment of the Ripening of Cobalt Clusters and Mixing Between Co and Ru Promoter via Oxidation-Reduction-Cycles over Lower Co-Loaded Ru-Co/A12O3 Catalysts

    SciTech Connect (OSTI)

    Jacobs,G.; Sarkar, A.; Ji, Y.; Luo, M.; Dozier, A.; Davis, B.

    2008-01-01

    A 2% Ru-promoted 15% Co/Al2O3 catalyst was tested after reduction and after being subjected to oxidation-reduction cycles. The catalysts were characterized over four oxidation-reduction cycles by XANES/EXAFS, TPR, HRTEM, and EDS elemental mapping. The oxidation-reduction treatments were found to assist in sintering the metallic clusters to a larger size, and to promote mixing on at least the order of the nanoscale. The larger crystallites in closer proximity to the Ru promoter led to a more facile reduction of the cobalt crystallites. In addition, a catalyst exposed to two oxidation-reduction cycles resulted in slightly higher conversion, higher a-value product, slightly lower methane selectivity, and greater stability over a reduced freshly calcined catalyst.

  12. Microsoft Word - FeV.doc

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

    Fe K-edge XAS spectra of the Fe(III)-azide precursor (black) and the Fe(V)-nitrido complex (red) Characterization of a Genuine S=1/2 Fe(V) Complex Núria Aliaga-Alcalde, 1 Serena DeBeer George, 2 Bernd Mienert, 1 Eckhard Bill, 1 Karl Wieghardt 1 and Frank Neese 11 1 Max Planck Institut für Bioanorganische Chemie, Mülheim an der Ruhr, Germany 2 Stanford Synchrotron Radiation Laboratory, SLAC, Stanford University, Stanford, CA High-valent Fe(IV) and Fe(V) intermediates are invoked in the

  13. 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.

  14. 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 4πMs. 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; 4πM19 (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

  15. 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 4πMs. 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; 4πM19 (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

  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 HClO₄ at 23°C, a CTR as low as 0.04 Ω cm² was obtained with only 20 μg cm⁻² Pt and 11 μg 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 <50 μg cm⁻² for the HER in proton-exchange-membrane water electrolyzers, we recorded uncompromised activity and durability compared to the baseline established with 3 mg cm⁻² Pt black.« less

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

    SciTech Connect (OSTI)

    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 HClO₄ at 23°C, a CTR as low as 0.04 Ω cm² was obtained with only 20 μg cm⁻² Pt and 11 μg cm⁻² Ru using the carbon-supported Ru@Pt with 1:1 Ru:Pt atomic ratio. Derived from temperature-dependent CTRs, the activation barrier 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 <50 μg cm⁻² for the HER in proton-exchange-membrane water electrolyzers, we recorded uncompromised activity and durability compared to the baseline established with 3 mg cm⁻² Pt black.

  18. Strain-induced topological transition in SrRu2O6 and CaOs2O6

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

    Ochi, Masayuki; Arita, Ryotaro; Trivedi, Nandini; Okamoto, Satoshi

    2016-05-24

    The topological property of SrRu$_2$O$_6$ and isostructural CaOs$_2$O$_6$ under various strain conditions is investigated using density functional theory. Based on an analysis of parity eigenvalues, we anticipate that a three-dimensional strong topological insulating state should be realized when band inversion is induced at the A point in the hexagonal Brillouin zone. For SrRu$_2$O$_6$, such a transition requires rather unrealistic tuning, where only the $c$ axis is reduced while other structural parameters are unchanged. However, given the larger spin-orbit coupling and smaller lattice constants in CaOs$_2$O$_6$, the desired topological transition does occur under uniform compressive strain. Our study paves a waymore » to realize a topological insulating state in a complex oxide, which has not been experimentally demonstrated so far.« less

  19. Giant spontaneous Hall effect in zero-moment Mn{sub 2}Ru{sub x}Ga

    SciTech Connect (OSTI)

    Thiyagarajah, Naganivetha; Lau, Yong-Chang; Betto, Davide; Borisov, Kiril; Coey, J. M. D.; Stamenov, Plamen; Rode, Karsten

    2015-03-23

    Spin-dependent transport properties of Mn{sub 2}Ru{sub x}Ga thin-films are studied as function of the Ru concentration and the substrate-induced strain. The large spontaneous Hall angle of 7.7% twenty times bigger than in other 3d metals is a signature of its half-metallicity. The compensation temperature where the magnetization of the two inequivalent antiferromagnetically coupled Mn sublattices cancel can be tuned by varying x or the biaxial strain. This zero-moment half metal is free from demagnetizing forces and creates no stray field, effectively removing two obstacles to integrating magnetic elements in densely packed, nanometer-scale memory elements, and millimeter-wave generators.

  20. Anisotropy of electrical and magnetic transport properties of epitaxial SrRuO{sub 3} thin films

    SciTech Connect (OSTI)

    Ning, X. K.; Wang, Z. J. Zhang, Z. D.

    2015-03-07

    SrRuO{sub 3} (SRO) thin films with different thickness (2–70 nm) have been grown on (001), (110), and (111) SrTiO{sub 3} substrates. The (001)-SRO films (2–8 nm) exhibited smooth flat surfaces whereas the (110)- and (111)-SRO films featured a faceted island structure. Room temperature resistivity and residual resistivity are the lowest for the (111)-SRO films (30–70 nm). Over all thicknesses, we observed enhanced magnetization in the (111)-SRO films (∼4 μ{sub B}/Ru) compared with that for the (001)- and (110)-SRO films (∼2 μ{sub B}/Ru and ∼3 μ{sub B}/Ru, respectively), suggesting a low-spin state t{sub 2g}(3↑,1↓), high-spin state t{sub 2g}(3↑)e{sub g}(1↑), and mixed low- and high-spin states for the (001)-, (111)-, and (110)-SRO films, respectively. The dependence of resistivity on temperatures near T{sub C} follows a power law with exponent β = 0.312 and β = 0.363 for the (110)- and (111)-SRO films, respectively. These critical exponents are consistent with magnetic data with scaling law M = C (T{sub C} − T){sup β}. At low temperatures, dM/dT and dρ/dT show a linear relationship in the temperature range for the Fermi liquid. These results suggest that the intrinsic electrical and magnetic transport properties are coupled.

  1. Determination of structure and phase transition of light element nanocomposites in mesoporous silica: case study of NH3BH3 in MCM-41

    SciTech Connect (OSTI)

    Kim, Hyun Jeong; Karkamkar, Abhijeet J.; Autrey, Thomas; Chupas, Peter; Proffen, Thomas E.

    2009-09-30

    The structure of ammonia borane (AB), NH3BH3, infused in mesoporous silica MCM-41 and its evolution over the temperature range of 80 to 300 K was investigated using the atomic pair distribution function (PDF) analysis of synchrotron X-ray powder diffraction data in order to understand the origin of improved dehydrogenation properties of the system. Our study shows how X-ray PDF analysis can be used to elucidate the structure of light guest species loaded in mesoporous silica materials despite of its low scattering power of composed elements (N, B, and H) compared to its host (SiO2). PDF analyses of two AB-loaded compositions with weight ratio AB:MCM-41=1:1 and 3:1 provide a strong evidence that AB aggregate, previously found in AB:MCM-41?1:1 samples, is same species as neat AB. For both of them an orthorhombic to tetragonal structural phase transition occurs at 225 K on warming. On the other hand, AB residing inside meso-pores, which is found in AB:MCM-41=1:2 sample, does not undergo such phase transition. It rather stays in tetragonal phase over a wide temperature range of 110 to 240 K and starts to lose structural correlation above 240 K. This strongly suggests that nano-confinement of AB inside meso-pores stabilizes high temperature tetragonal phase at much lower temperature. These results provide important clues to two critical questions: why nan-compositions of AB leads dehydrogenation to lower temperature and why the neat AB like propoerties are recovered at high AB loading samples. This work was supported by the US Department of Energy Office of Basic Energy Sciences, Chemical Sciences program. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  2. Oxidation and reduction under cover: Chemistry at the confined space between ultra-thin nanoporous silicates and Ru(0001)

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

    J. Anibal Boscoboinik; Zhong, Jian -Qiang; Kestell, John; Waluyo, Iradwikanari; Wilkins, Stuart; Mazzoli, Claudio; Barbour, Andi; Kaznatcheev, Konstantine; Shete, Meere; Tsapatsis, Michael

    2016-03-23

    The oxidation and reduction of Ru(0001) surfaces at the confined space between two-dimensional nanoporous silica frameworks and Ru(0001) have been investigated using synchrotron-based ambient pressure X-ray photoelectron spectroscopy (AP-XPS). The porous nature of the frameworks and the weak interaction between the silica and the ruthenium substrate allow oxygen and hydrogen molecules to go through the nanopores and react with the metal at the interface between the silica framework and the metal surface. In this work, three types of two-dimensional silica frameworks have been used to study their influence in the oxidation and reduction of the ruthenium surface at elevated pressuresmore » and temperatures. These frameworks are bilayer silica (0.5 nm thick), bilayer aluminosilicate (0.5 nm thick), and zeolite MFI nanosheets (3 nm thick). It is found that the silica frameworks stay essentially intact under these conditions, but they strongly affect the oxidation of ruthenium, with the 0.5 nm thick aluminosilicate bilayer completely inhibiting the oxidation. Furthermore, the latter is believed to be related to the lower chemisorbed oxygen content arising from electrostatic interactions between the negatively charged aluminosilicate framework and the Ru(0001) substrate.« less

  3. NNMCAB Board Minutes: September 2006 Santa Fe

    Broader source: Energy.gov [DOE]

    Minutes of the September 27, 2006 Board meeting at Santa Fe Community College Presentation LANL, Transuranic Waste Program, Lee Lucero

  4. NNMCAB Board Minutes: January 2006 Santa Fe

    Broader source: Energy.gov [DOE]

    Minutes of the January 25, 2006 Board meeting at Santa Fe Community College Presentation LANL, Groundwater Issues

  5. NNMCAB Board Minutes: June 2001 Santa Fe

    Broader source: Energy.gov [DOE]

    Minutes of the June 20, 2001 Board meeting at Hotel Santa Fe Presentation NNMCAB Waste Management Committee

  6. NNMCAB Board Minutes: November 2010 Santa Fe

    Broader source: Energy.gov [DOE]

    Minutes of the November 17, 2010 Board meeting at Lodge at Santa Fe Presentation LANL, Environmental Surveillance Report for 2009

  7. NNMCAB Board Minutes: September 2008 Santa Fe

    Broader source: Energy.gov [DOE]

    Minutes of the September 24, 2008 Board meeting at Santa Fe Community College Consideration and Action on Recommendations

  8. NNMCAB Board Minutes: July 2008 Santa Fe

    Broader source: Energy.gov [DOE]

    Minutes of the July 30, 2008 Board meeting at Santa Fe Community College Presentation LANL, Upcoming Consent Order Deliverables

  9. 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

  10. Santa Fe Jets and Heavy Flavor Workshop

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

    Santa Fe Jets and Heavy Flavor Workshop Santa Fe Jets and Heavy Flavor Workshop WHEN: Jan 11, 2016 8:30 AM - Jan 13, 2016 5:30 PM WHERE: Inn and Spa at Loretto 211 Old Santa Fe Trail Santa Fe, New Mexico 87501 USA CONTACT: Ivan Vitev CATEGORY: Science TYPE: Conference INTERNAL: Calendar Login Event Description This workshop will bring together senior researchers, postdoctoral fellows and talented graduate students to discuss the exciting recent developments and future directions in high energy

  11. Ceria nanoclusters on graphene/Ru(0001): A new model catalyst system

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

    Novotny, Z.; Netzer, F. P.; Dohnalek, Z.

    2016-03-22

    In this study, the growth of ceria nanoclusters on single-layer graphene on Ru(0001) has been examined, with a view towards fabricating a stable system for model catalysis studies. The surface morphology and cluster distribution as a function of oxide coverage and substrate temperature has been monitored by scanning tunneling microscopy (STM), whereas the chemical composition of the cluster deposits has been determined by Auger electron spectroscopy (AES). The ceria nanoparticles are of the CeO2(111)-type and are anchored at the intrinsic defects of the graphene surface, resulting in a variation of the cluster densities across the macroscopic sample surface. The ceriamore » clusters on graphene display a remarkable stability against reduction in ultrahigh vacuum up to 900 K, but some sintering of clusters is observed for temperatures > 450 K. The evolution of the cluster size distribution suggests that the sintering proceeds via a Smoluchowski ripening mechanism, i.e. diffusion and aggregation of entire clusters.« less

  12. 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.

  13. 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

  14. Structure and Reactivity of Pt-Ru/SiO2 Catalysts for the Preferential Oxidation of CO Under Excess H2

    SciTech Connect (OSTI)

    Chin,S.; Alexeev, O.; Amiridis, J.

    2006-01-01

    SiO{sub 2}-supported Pt-Ru bimetallic catalysts subjected to two different types of pretreatment protocols (i.e., subsequent oxidation-reduction treatments at 300 C and direct reduction in H{sub 2} at 300 C) were characterized by extended X-ray absorption fine structure spectroscopy (EXAFS), scanning transmission electron microscopy (STEM), Fourier transform infrared spectroscopy (FTIR) of adsorbed CO, and catalytic activity measurements for the preferential oxidation of CO in the presence of excess H{sub 2} (PROX). The EXAFS data show that both treatments led to the formation of dispersed bimetallic structures, with an average Pt-Ru bond distance of 2.68 {angstrom}. The close proximity between Pt and Ru helped stabilize Ru in a highly dispersed form and prevented its sintering after oxidation treatments. The FTIR results indicate that the adsorption of CO was substantially weaker on bimetallic samples than on the corresponding monometallic ones. Interparticle segregation (i.e., segregation of the two metals into individual particles) was observed with the Pt-Ru/SiO{sub 2} sample exposed to direct H{sub 2} treatment; in contrast, intraparticle segregation (i.e., segregation of the two metals within the same particle), with Pt preferentially occupying more surface sites, was observed when consequent O{sub 2}/H{sub 2} treatments were used. As a result, the direct H{sub 2} treatment yielded samples with PROX activity almost identical to that of monometallic Ru catalysts, whereas the O{sub 2}/H{sub 2} treatment yielded samples with PROX activity intermediate to those of monometallic Pt and Ru catalysts.

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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-κ-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

  1. Synthesis of high magnetization Fe and FeCo nanoparticles by high temperature chemical reduction

    SciTech Connect (OSTI)

    Kandapallil, B; Colborn, RE; Bonitatibus, PJ; Johnson, F

    2015-03-15

    Fe and FeCo ferromagnetic nanoparticles in the 5-10 nm size regimes featuring high magnetization were synthesized using a modified chemical reduction method. The structure and morphology of these nanoparticles were confirmed by XRD and TOM analysis. These small, monodisperse and phase pure nanoparticles exhibited magnetic saturation of 210 emu/g (Fe) and 220 emu/g (Fe+Co) for Fe and FeCo nanoparticles respectively. The magnetization was found to be dependent on the temperature at which the reducing agent was introduced. (C) 2014 Elsevier B.V. All rights reserved,

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

    SciTech Connect (OSTI)

    Balman, Soelen; Godon, Patrick; Sion, Edward M.; Ness, Jan-Uwe; Schlegel, Eric; Barrett, Paul E.; Szkody, Paula E-mail: patrick.godon@villanova.edu E-mail: juness@sciops.esa.int E-mail: barrett.paul@usno.navy.mil

    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.

  3. Suhr 7900.955 L*E+ru Pkzza. S. Iv.. Washington, D.C. 20024-i

    Office of Legacy Management (LM)

    Suhr 7900.955 L*E+ru Pkzza. S. Iv.. Washington, D.C. 20024-i 7117~03.8J.cdy.4 23 September 19E M r. Andrew Wallo, III, NE-23 Division of Facility & Site Decommissioning Projects U.S. Department of Energy Germantown, Maryland 20545 Dear M r. Wallo: ELIMINATION RECOMMENDATION -- COLLEGES AND UN11 The attached elimination recommendation was prepar with your suggestion during our meeting on 22 September includes 26 colleges and universities identified.in Enc Aerospace letter subject: Status of

  4. 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.

  5. Fe-based long range ordered alloys

    DOE Patents [OSTI]

    Liu, Chain T; Inouye, Henry; Schaffhauser, Anthony C.

    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.

  6. Fe-based long range ordered alloys

    DOE Patents [OSTI]

    Liu, C.T.

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

  7. Spontaneous orientation-tuning driven by the strain variation in self-assembled ZnO-SrRuO{sub 3} heteroepitaxy

    SciTech Connect (OSTI)

    Zhu, Yuanmin; Liu, Ruirui; Zhan, Qian; Chang, Wei Sea; Yu, Rong; Wei, Tzu-Chiao; He, Jr-Hau; Chu, Ying-Hao

    2015-11-09

    Heteroepitaxial ZnO and SrRuO{sub 3} were grown on SrTiO{sub 3} (111) substrates and formed a self-assembled wurtzite-perovskite nanostructure. Spontaneous orientation-tuning of the SrRuO{sub 3} pillars was observed, with the growth direction changing from [111]{sub SRO} to [011]{sub SRO} as the film thickness increased, which is attributed to a misfit strain transition from the biaxial strain imposed by the SrTiO{sub 3} substrate to the vertical strain provided by the ZnO matrix. The [011]-SrRuO{sub 3} and [0001]-ZnO combination presents a favorable matching in the nanocomposite films, resulting in higher charge carrier mobility. This vertically integrated configuration and regulation on the crystallographic orientations are expected to be employed in designing multi-functional nanocomposite systems for applications in electronic devices.

  8. 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.

  9. 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.

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

    SciTech Connect (OSTI)

    Ongrai, O.; Pearce, J. V.; Machin, G.; Sweeney, S. J.

    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.

  11. FE Blog | Department of Energy

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

    Blog FE Blog RSS August 3, 2016 NETL researcher Kelly Rose, co-developer of one of the four NETL technologies chosen as finalists for the 2016 R&D 100 Awards Game-Changing NETL Technologies Named Finalists for Prestigious R&D 100 Awards Four technologies developed by researchers at the National Energy Technology Laboratory (NETL) have been named finalists for this year's R&D 100 Awards. The selected technologies reflect the laboratory's focus on science and technology innovations

  12. Santa Fe Community College selects new president

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

    Santa Fe Community College Selects New President Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue: September 1, 2016 all issues All Issues » submit Santa Fe Community College selects new president Santa Fe Community College's new president will be Dr. Ana Margarita "Cha" Guzmán. August 1, 2012 dummy image Read our archives Contacts Editor Linda Anderman Email Community Programs Office Kurt Steinhaus Email Beginning September

  13. FE - Fossil Energy - Energy Conservation Plan

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

    Enclosure (1) Office of Fossil Energy Energy Conservation Plan The Office of Fossil Energy (FE) strongly supports the implementation of strategies to reduce energy consumption in the Headquarters buildings. FE engaged its employees by sending an office-wide email soliciting input for this plan; the ideas were then compiled into this document. The focus of this plan is on how FE employees can change their behavior to reduce energy consumption. This plan purposefully excludes measures that would

  14. Equations of state in the Fe-FeSi system at high pressures and...

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Search Results Journal Article: Equations of state in the Fe-FeSi system ... Country of Publication: United States Language: ENGLISH Word Cloud More Like This Full ...

  15. High-pressure viscosity of liquid Fe and FeS revisited by falling...

    Office of Scientific and Technical Information (OSTI)

    High-pressure viscosity of liquid Fe and FeS revisited by falling sphere viscometry using ultrafast X-ray imaging Citation Details In-Document Search This content will become ...

  16. 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.

  17. NNMCAB Board Minutes: July 2006 Santa Fe

    Broader source: Energy.gov [DOE]

    Minutes of the July 26, 2006 Board meeting at Santa Fe Community College Consideration and Action on Recommendation 2006-05 and 2006-07

  18. NNMCAB Board Agenda: December 2014 Santa Fe

    Broader source: Energy.gov [DOE]

    Agenda for the December 10, 2014 Special Board meeting at Lodge at Santa Fe Presentation DOE, Transition EM Legacy Clean-up at Los Alamos, Jack Craig

  19. NNMCAB Board Minutes: January 2008 Santa Fe

    Broader source: Energy.gov [DOE]

    Minutes of the January 30, 2008 Board meeting at Santa Fe Community College Presentation DOE, Quarterly Progress Review and Budget Update on Environmental Programs at LANL, David Gregory

  20. NNMCAB Board Minutes: September 2005 Santa Fe

    Broader source: Energy.gov [DOE]

    Minutes of the September 28, 2005 Board meeting at Santa Fe Community College Presentation Risk Assessment Corporation, Risk Assessments, Helen Grogan Consideration and Action on Recommendations

  1. NNMCAB Board Minutes: September 2007 Santa Fe

    Broader source: Energy.gov [DOE]

    Minutes of the September 19, 2007 Board meeting at Santa Fe Community College Presentation DOE, Quarterly Performance Reports on Environmental Programs, George Rael

  2. NNMCAB Board Minutes: March 2008 Santa Fe

    Broader source: Energy.gov [DOE]

    Minutes of the March 26, 2008 Board meeting at Santa Fe Community College Presentations LANL, How Does LANL Conduce Risk Assessment, Rich Mirenda

  3. NNMCAB Board Minutes: November 2007 Santa Fe

    Broader source: Energy.gov [DOE]

    Minutes of the November 28, 2007 Board meeting at Santa Fe Community College Presentation LANL, LANL Responses to 17 National Academies of Sciences Recommendations Regarding Groundwater Monitoring, Huber

  4. fe0024271-utaustin | netl.doe.gov

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

    Fracture Diagnostics Using Low Frequency Electromagnetic Induction and Electrically Conductive Proppants Last Reviewed 12415 DE-FE0024271 Goal The project goal is to develop a...

  5. NNMCAB Board Minutes: January 2014 Santa Fe

    Broader source: Energy.gov [DOE]

    Minutes of the January 29, 2014 Board meeting at Lodge at Santa Fe Presentation DOE/LANL, Material Disposal Area G, Pete Maggiore, Jeff Mousseau

  6. NNMCAB Board Minutes: May 2013 Santa Fe

    Broader source: Energy.gov [DOE]

    Minutes of the May 22, 2013 Board meeting at The Lodge at Santa Fe Presentation LANL, Update on Chromium Filed Work, Dave McInroy, Danny Katzman

  7. 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 ...

  8. FE0001175_PTTC | netl.doe.gov

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

    Department of Energy FE-Supported Research Looks to Coal as a Source for Rare Earth Elements FE-Supported Research Looks to Coal as a Source for Rare Earth Elements June 16, 2016 - 8:34am Addthis FE-Supported Research Looks to Coal as a Source for Rare Earth Elements The Energy Department's Office of Fossil Energy (FE) has a robust clean energy research and development (R&D) program dedicated to making coal both cleaner and more sustainable. You may have heard about some of the

  9. Microsoft Word - Fe-S_Clusters

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

    April 2010 Figure 1. Top: overall ribbon and surface representation of the x-ray crystal structure of [FeFe]-hydrogenase HydA ΔEFG . Loop regions important for the cluster insertion process are colored green. Bottom: Ball and stick representation of the active site of HydA ΔEFG at which a [4Fe-4S] cluster is present. Coloring scheme: rust, iron; orange, sulfur; gray, carbon; red, oxygen; blue, nitrogen. Assembly and Evolution of Complex Fe-S Clusters as Revealed by X-ray Crystallography

  10. 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.

  11. InP:Fe Photoconducting device

    DOE Patents [OSTI]

    Hammond, Robert B.; Paulter, Nicholas G.; Wagner, Ronald S.

    1984-01-01

    A photoconducting device fabricated from Fe-doped, semi-insulating InP crystals exhibits an exponential decay transient with decay time inversely related to Fe concentration. Photoconductive gain as high as 5 is demonstrated in photoconducting devices with AuGe and AuSn contacts. Response times from 150 to 1000 picoseconds can be achieved.

  12. InP:Fe photoconducting device

    DOE Patents [OSTI]

    Hammond, R.B.; Paulter, N.G.; Wagner, R.S.

    A photoconducting device fabricated from Fe-doped, semi-insulating InP crystals exhibits an exponential decay transient with decay time inversely related to Fe concentration. Photoconductive gain as high as 5 is demonstrated in photoconducting devices with AuGe and AuSn contacts. Response times from 150 to 1000 picoseconds can be achieved.

  13. A Series of Highly Stable Mesoporous Metalloporphyrin Fe-MOFs...

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

    A series of mesoporous metalloporphyrin Fe-MOFs, namely PCN-600(M) (M Mn, Fe, Co, Ni, Cu), have been synthesized using the preassembled Fe3O(OOCCH3)6 building block....

  14. FE FY 2016 BUDGET REQUEST PRESENTATION | Department of Energy

    Energy Savers [EERE]

    PRESENTATION FE FY 2016 BUDGET REQUEST PRESENTATION FY16budgetrollout 2-2-15.pdf (967.91 KB) More Documents & Publications FE FY 2015 Budget Request Presentation FE FY 2017

  15. FE FY 2015 Budget Request Presentation | Department of Energy

    Energy Savers [EERE]

    5 Budget Request Presentation FE FY 2015 Budget Request Presentation fy15budgetrollout.pptx (4.07 MB) More Documents & Publications FE FY 2017 BUDGET REQUEST PRESENTATION FE FY ...

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

    SciTech Connect (OSTI)

    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 (300C) 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 important catalysis and energy storage applications.

  17. 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

  18. 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).

  19. SEMI-ANNUAL REPORTS -- WENTWORTH GAS MARKETING LLC - FTA - FE...

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

    - TEXAS LNG BROWNSVILLE LLC - FE DKT. 15-62-LNG - Order 3716 FTA Wentworth Gas Martketing LLC - FE Dkt. No. 14-63-CNG

  20. A Series of Highly Stable Mesoporous Metalloporphyrin Fe-MOFs...

    Office of Scientific and Technical Information (OSTI)

    A Series of Highly Stable Mesoporous Metalloporphyrin Fe-MOFs Citation Details In-Document Search Title: A Series of Highly Stable Mesoporous Metalloporphyrin Fe-MOFs Authors: ...

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

    Office of Scientific and Technical Information (OSTI)

    Isolation and microbial reduction of Fe(III) phyllosilicates from subsurface sediments Citation Details In-Document Search Title: Isolation and microbial reduction of Fe(III) ...

  2. NNMCAB Board Minutes: September 2009 Santa Fe | Department of...

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

    - September 30, 2009 More Documents & Publications NNMCAB Board Minutes: May 2009 Santa Fe NNMCAB Board Minutes: January 2009 Santa Fe NNMCAB Board Minutes: March 2009 Santa...

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

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

    SANDIA CORPORATION SF 6432-FE (112015) SECTION II STANDARD TERMS AND CONDITIONS FOR FIXED ... FOR HIRE Control : SF 6432-FE Title: Standard Terms & Conditions for Fixed Price ...

  4. 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 0.51?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 700750?C.

  5. 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 Print This Page print Performer: Research Triangle Institute fe0023592-image.jpg Block Flow Diagram of Hybrid Integrated CTL Process Website: Research Triangle Institute Award Number: FE0023592 Project Duration: 10/01/2014 - 03/31/2017 Total Award Value: $5,500,000.00 DOD Share: $3,981,705.00 DOE Share: $418,295.00

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

    SciTech Connect (OSTI)

    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 variable 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.

  7. Analysis of the electrochemical characteristics of a direct methanol fuel cell based on a Pt-Ru/C anode catalyst

    SciTech Connect (OSTI)

    Arico, A.S.; Creti, P.; Mantegna, R.

    1996-12-31

    This paper deals with a vapour-feed direct methanol fuel cell (DMFC) based on a Nafion 117{reg_sign} solid polymer electrolyte. Pt-Ru/C and Pt/C catalysts were employed for methanol oxidation and oxygen reduction, respectively. Structure and surface chemistry of catalysts were investigated by X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Membrane/electrode assembly (M&E) was prepared by using a {open_quotes}paste process{close_quotes} method. Electrical power densities of about 150 mW cm{sup -2} were obtained at 95{degrees} C with Pt loadings of 0.8 and 0.5 mg cm{sup -2} at anode and cathode respectively.

  8. fe0024311-ttu | netl.doe.gov

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

    Maximize Liquid Oil Production from Shale Oil and Gas Condensate Reservoirs by Cyclic Gas Injection Last Reviewed 5202016 DE-FE0024311 Goal The project goal is to evaluate the ...

  9. NNMCAB Board Minutes: July 2005 Santa Fe

    Broader source: Energy.gov [DOE]

    Minutes of the July 27, 2005 Board meeting at Santa Fe Community College Presentation LANL, Public Health Assessment for Los Alamos National Laboratory, Michael Brooks Presentation LANL, Well Drilling Techniques, Groundwater Program

  10. NNMCAB Board Agenda: January 2014 Santa Fe

    Broader source: Energy.gov [DOE]

    Agenda for the January 29, 2014 Board meeting at Lodge at Santa Fe Presentation DOE.LANL, MDA-G Post TRU Waste Retrieval Proposed Remedy; A Path to Long Term Stewardship, Pete Maggiore, Jeff Mousseau

  11. NNMCAB Board Minutes: March 2005 Santa Fe

    Broader source: Energy.gov [DOE]

    Minutes of the March 30, 2005 Board meeting at Santa Fe Community College Consideration and Action on Recommendation 2005-03 Consideration and Action on Recommendation 2005-04

  12. NNMCAB Board Minutes: December 2014 Santa Fe

    Broader source: Energy.gov [DOE]

    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

  13. NNMCAB Board Minutes: March 2010 Santa Fe

    Broader source: Energy.gov [DOE]

    Minutes of the March 31, 2010 Board meeting at Lodge at Santa Fe Presentation DOE/LANL Los Alamos National Security Reorganization, George Rael, Michael Graham Presentation DOE, Inventory of Waste at Area G, George Henkel

  14. FE0023592 | netl.doe.gov

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

    FE0023592 Project Duration: 10012014 - 03312017 Total Award Value: 5,500,000.00 DOD Share: 3,981,705.00 DOE Share: 418,295.00 Performer Share: 1,100,000.00 Technology ...

  15. fe0001547 | netl.doe.gov

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

    1547 Recovery Act: CO2 Capture From Biofuels Production and Sequestration into the Mt. Simon Sandstone Reservoir Email Page email Print This Page print Performer: Archer Daniels Midland Corporation (ADM) fe0001547 ADM's Agricultural Processing and Biofuels Plant, Decatur, IL. Website: Archer Daniels Midland Corporation (ADM) Award Number: FE0001547 Project Duration: 11/16/2009 - 09/30/2017 Total Award Value: $207,942,199.00 DOE Share: $141,405,945.00 Performer Share: $66,536,254.00 Technology

  16. fe0024360-paulsson | netl.doe.gov

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

    fe0024360-paulsson Injection and Tracking of Micro-seismic emitters to Optimize Unconventional Oil and Gas (UOG) Development Last Reviewed 6/14/2016 DE-FE0024360 Goal The project goal is to develop fracture and fractureproppant mapping and monitoring technologies that will allow for both efficient and environmentally prudent development of UOG by developing and simultaneously deploying two novel technologies in an UOG well. The first technology, an acoustic micro emitter (AME) can be mixed with

  17. DNA analysis conference in Santa Fe

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

    DNA analysis conference in Santa Fe DNA analysis conference in Santa Fe Los Alamos National Laboratory is hosting a DNA sequence analysis and bioinformatics event, the 10th annual Sequencing, Finishing and Analysis in the Future (SFAF) workshop. May 27, 2015 DNA extracted from a soil sample is stored in a small vial of clear liquid. In general, living cells function by using the sequences of bases in their DNA as a blueprint for assembling proteins. A particularly important type of protein is

  18. Identification of Highly Active Fe Sites in (Ni,Fe)OOH for Electrocatalytic

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

    Water Splitting | Stanford Synchrotron Radiation Lightsource Identification of Highly Active Fe Sites in (Ni,Fe)OOH for Electrocatalytic Water Splitting Thursday, April 30, 2015 Operando XAS showing structural changes at Fe dopants in Ni(OH)2/NiOOH host structure. Ni(OH)2 is oxidized into γ-NiOOH under OER operating conditions, inducing significant M-O bond contraction at both Ni and Fe sites. Theoretical modeling of site specific OER overpotentials using DFT+U reveals the origin of

  19. Transverse thermoelectric effect in La{sub 0.67}Sr{sub 0.33}MnO{sub 3}|SrRuO{sub 3} superlattices

    SciTech Connect (OSTI)

    Shiomi, Y.; Handa, Y.; Kikkawa, T.; Saitoh, E.

    2015-06-08

    Transverse thermoelectric effects in response to an out-of-plane heat current have been studied in an external magnetic field for ferromagnetic superlattices consisting of La{sub 0.67}Sr{sub 0.33}MnO{sub 3} and SrRuO{sub 3} layers. The superlattices were fabricated on SrTiO{sub 3} substrates by pulsed laser deposition. We found that the sign of the transverse thermoelectric voltage for the superlattices is opposite to that for La{sub 0.67}Sr{sub 0.33}MnO{sub 3} and SrRuO{sub 3} single layers at 200?K, implying an important role of spin Seebeck effects inside the superlattices. At 10?K, the magnetothermoelectric curves shift from the zero field due to an antiferromagnetic coupling between layers in the superlattices.

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

    SciTech Connect (OSTI)

    Aczel, Adam A; Bugaris, Dan; Li, Ling; Yan, Jiaqiang; Dela Cruz, Clarina R; Zur Loye, Hans-Conrad; Nagler, Stephen E

    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.

  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. The mechanical properties of FeAl

    SciTech Connect (OSTI)

    Baker, I.; George, E.P.

    1996-12-31

    Only in the last few years has progress been made in obtaining reproducible mechanical properties data for FeAl. Two sets of observations are the foundation of this progress. The first is that the large vacancy concentrations that exist in FeAl at high temperature are easily retained at low temperature and that these strongly affect the low-temperature mechanical properties. The second is that RT ductility is adversely affected by water vapor. Purpose of this paper is not to present a comprehensive overview of the mechanical properties of FeAl but rather to highlight our understanding of key phenomena and to show how an understanding of the factors which control the yield strength and fracture behavior has followed the discovery of the above two effects. 87 refs, 9 figs.

  3. Magnetoelasticity of Fe-Si single crystals

    SciTech Connect (OSTI)

    Xing, Q; Wu, D.; Lograsso, T. A.

    2010-04-20

    The tetragonal magnetostriction constant, (3/2){lambda}{sub 100}, of Fe-Si single crystals was measured and was found to be structure dependent. Similar to that of Fe-Ge single crystals, (3/2){lambda}{sub 100} is positive in the single phase A2 regime, becomes negative in the single phase D0{sub 3} regime, and changes from positive to negative between the two regimes. Short-range order in the A2 regime decreases the magnetostriction prior to the onset of long range order. In the single phase regions of both A2 and D0{sub 3}, thermal history does not show any obvious effect on the magnetostriction, contrary to that found for Fe-Ga alloys. However, in the regions of phase mixture involving A2, B2, and D0{sub 3} phases, quenching pushes the change in magnetostriction from positive to negative to higher Si contents.

  4. Influence of piezoelectric strain on the Raman spectra of BiFeO3 films deposited on PMN-PT substrates

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

    Himcinschi, Cameliu; Guo, Er -Jia; Talkenberger, Andreas; Dorr, Kathrin; Kortus, Jens

    2016-01-27

    In this study, BiFeO3 epitaxial thin films were deposited on piezoelectric 0.72Pb(Mg1/3Nb2/3)O3-0.28PbTiO3 (PMN-PT) substrates with a conductive buffer layer (La0.7Sr0.3MnO3 or SrRuO3) using pulsed laser deposition. The calibration of the strain values induced by the electric field applied on the piezoelectric PMN-PT substrates was realised using X-Ray diffraction measurements. The method of piezoelectrically induced strain allows to obtain a quantitative correlation between strain and the shift of the Raman-active phonons, ruling out the influence of extrinsic factors, such as growth conditions, crystalline quality of substrates, or film thickness. Using the Poisson number for BiFeO3 one can determine the volume changemore » induced by strain, and therefore the Gr neisen parameters for specific phonon modes.« less

  5. Magnetic interaction in oxygenated alpha Fe-phthalocyanines

    SciTech Connect (OSTI)

    Kuzmann, Ern?, E-mail: kuzmann@caesar.elte.hu; Homonnay, Zoltn; Horvth, Attila [Institute of Chemistry, Etvs Lornd 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); Klencsr, Zoltn [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 Mssbauer spectroscopy, magnetization measurements (SQUID) and X-ray diffractometry (XRD). Mssbauer 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 Mssbauer spectra in a 5 T external magnetic field at 5K and magnetization measurements indicate antiferromagnetic coupling in oxygenated ?-FePc.

  6. Membrane separation advances in FE hydrogen program

    SciTech Connect (OSTI)

    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.

  7. FE Categorical Exclusions | Department of Energy

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

    FE Categorical Exclusions FE Categorical Exclusions RSS May 25, 2016 CX-200007 Categorical Exclusion Determination Cheniere Marketing, LLC CX(s) Applied: B5.7 Date: 05/25/2016 Location(s): Texas Office(s): Fossil Energy, Natural Gas Regulation May 18, 2016 CX-200008 Categorical Exclusion Determination Flint Hills Resources, LP CX(s) Applied: B5.7 Date: 05/18/2016 Location(s): Texas Office(s): Fossil Energy, Natural Gas Regulation January 28, 2016 CX-200006: Categorical Exclusion Determination

  8. fe0000663 | netl.doe.gov

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

    0663 Recovery Act: Hydrogen Energy California Project: Commercial Demonstration of Advanced IGCC with Full Carbon Capture Email Page email Print This Page print Performer: Hydrogen Energy California LLC (HECA) FE0000663.jpg Website: Hydrogen Energy California LLC (HECA) Award Number: FE0000663 Project Duration: 10/1/2009 - 11/1/2018 Total Award Value: $4,028,136,691.001 DOE Share: $408,000,000.00 Performer Share: $3,620,136,691.00 Technology Area: Clean Coal Power Initiative (CCPI) Key

  9. fe0002650 | netl.doe.gov

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

    2650 Recovery Act: Texas Clean Energy Project Email Page email Print This Page print Performer: Summit Texas Clean Energy LLC FE0002650-1-.jpg Rendering of TCEP Facility Website: Summit Texas Clean Energy LLC Award Number: FE0002650 Project Duration: 02/01/2010 - 07/15/20171 Total Award Value: $1,726,628,229.002 DOE Share: $450,000,000.00 Performer Share: $1,276,628,229.00 Technology Area: Clean Coal Power Initiative (CCPI) Key Technology: Advanced Gasification, Advanced Turbines, Carbon Dioxide

  10. Pressure suppression of unconventional charge-density-wave state in PrRu4P12 studied by optical conductivity

    SciTech Connect (OSTI)

    Okamura H.; Carr G.; Ohta, N.; Takigawa, A.; Matsutori, I.; Shoji, K.; Miyata, K.; Matsunami, M.; Nanba, T.; Sugawara, H.; Sekine, C.; Shirotani, I.; Sato, H.; Moriwaki, T.; Ikemoto, Y.; Liu, Z.

    2012-05-09

    Optical conductivity [{delta}({omega})] of PrRu{sub 4}P{sub 12} has been studied under high pressure to 14 GPa, at low temperatures to 8 K, and at photon energies 12 meV-1.1 eV. The energy gap in {delta}({omega}) at ambient pressure, caused by a metal-insulator transition due to an unconventional charge-density-wave formation at 63 K, is gradually filled in with increasing pressure to 10 GPa. At 14 GPa and below 30 K, {delta}({omega}) exhibits a pronounced Drude-type component due to free carriers. This indicates that the initial insulating ground state at zero pressure has been turned into a metallic one at 14 GPa. This is consistent with a previous resistivity study under pressure, where the resistivity rapidly decreased with cooling below 30 K at 14 GPa. The evolution of electronic structure with pressure is discussed in terms of the hybridization between the 4f and conduction electrons.