Sample records for transition metal oxide

  1. Nanostructured transition metal oxides useful for water oxidation catalysis

    DOE Patents [OSTI]

    Frei, Heinz M; Jiao, Feng

    2013-12-24T23:59:59.000Z

    The present invention provides for a composition comprising a nanostructured transition metal oxide capable of oxidizing two H.sub.2O molecules to obtain four protons. In some embodiments of the invention, the composition further comprises a porous matrix wherein the nanocluster of the transition metal oxide is embedded on and/or in the porous matrix.

  2. Pressure-Induced Electronic Phase Transitions Transition Metal Oxides and Rare Earth Metals

    E-Print Network [OSTI]

    Islam, M. Saif

    Pressure-Induced Electronic Phase Transitions in Transition Metal Oxides and Rare Earth Metals Metal Oxides and Rare Earth Metals by Brian Ross Maddox Electron correlation can affect profound changes transition in a transition metal monoxide. iv #12;The lanthanides (the 4f metals also known as rare-earths

  3. Synthesis and characterization of nanostructured transition metal oxides for energy storage devices

    E-Print Network [OSTI]

    Kim, Jong Woung

    2012-01-01T23:59:59.000Z

    nanostructured transition metal oxides for energy storage devicesnanostructured transition metal oxides for energy storage devices

  4. Transition metal oxide improves overall efficiency and maintains performance with inexpensive metals.

    E-Print Network [OSTI]

    Transition metal oxide improves overall efficiency and maintains performance with inexpensive that inserting a transition metal oxide (TMO) between the lead sulfide (PbS) quantum dot (QD) layer and the metal-Yu Chen; Octavi E. Semonin; Arthur J. Nozik; Randy J. Ellingson; Matthew C. Beard."n-Type Transition Metal

  5. Activation of flue gas nitrogen oxides by transition metal complexes

    SciTech Connect (OSTI)

    Miller, M.E.; Finseth, D.H.; Pennline, H.W.

    1987-01-01T23:59:59.000Z

    Sulfur and nitrogen oxides are major flue gas pollutants released by coal-fired electric power plants. In the atmosphere these oxides are converted to sulfuric and nitric acids, which contribute to the acid rain problem. Most of the nitrogen oxides (90%-95%) present in coal-derived flue gas exist as the relatively inert and water-insoluble nitric oxide (NO), thus presenting a difficult removal problem. A practical strategy for nitrogen oxides removal might utilize a solid support that has been impregnated with an active transition metal complex. Some supported transition metals are expected to remove NO/sub x/ by sorption, with regeneration of the sorbent being a necessary property. Others catalyze NO oxidation to the more soluble NO/sub 2/ and N/sub 2/O/sub 5/, which has been demonstrated for certain transition metal species. These activated nitrogen oxides can be more efficiently removed along with SO/sub 2/ in conventional scrubbing or spray-drying processes, in which an aqueous slurry of sorbent, such as hydrated lime, is injected into the hot flue gas. We present here preliminary studies intended to establish basic homogeneous chemistry of transition metal complexes with nitrogen oxides. The transition metals considered in this work are volatile carbonyl complexes. This work is the first step in the development of supported metal species for enhanced nitrogen oxides removal.

  6. Charge, orbital and magnetic ordering in transition metal oxides 

    E-Print Network [OSTI]

    Senn, Mark Stephen

    2013-06-29T23:59:59.000Z

    Neutron and x-ray diffraction has been used to study charge, orbital and magnetic ordering in some transition metal oxides. The long standing controversy regarding the nature of the ground state (Verwey structure) of the ...

  7. Activation of flue gas nitrogen oxides by transition metal complexes

    SciTech Connect (OSTI)

    Miller, M.E.; Finseth, D.H.; Pennline, H.W.

    1987-01-01T23:59:59.000Z

    Sulfur and nitrogen oxides are major flue gas pollutants released by coal-fired electric power plants. In the atmosphere these oxides are converted to sulfuric and nitric acids, which contribute to the acid rain problem. Most of the nitrogen oxides present in coal-derived flue gas exist as the relatively inert and water-insoluble nitric oxide (NO), thus presenting a difficult removal problem. We present preliminary studies intended to establish basic homogeneous chemistry of transition metal complexes with nitrogen oxides. The transition metals considered in this work are volatile carbonyl complexes. The metal carbonyls took up nitric oxide homogeneously in the gas phase. Iron required uv light for reaction with NO, but the same result is expected with the application of heat. Metal carbonyls also reacted with nitrogen dioxide but produced polynuclear metal species. Oxygen did not attack the carbonyl or nitrosyl complexes. Results indicate high potential for NO/sub x/ removal from stack gases by sorption onto supported metal carbonyl complexes. The solid form allows ease in separation from the flue gas. Regeneration of the sorbent might be achieved by treating with CO to liberate NO/sub x/ by displacement or by heating to decompose and drive off NO/sub x/.

  8. High-Pressure Thermodynamic Properties of f-electron Metals, Transition Metal Oxides, and Half-Metallic Magnets

    SciTech Connect (OSTI)

    Richard T. Scalettar; Warren E. Pickett

    2005-08-02T23:59:59.000Z

    This project involves research into the thermodynamic properties of f-electron metals, transition metal oxides, and half-metallic magnets at high pressure. These materials are ones in which the changing importance of electron-electron interactions as the distance between atoms is varied can tune the system through phase transitions from localized to delocalized electrons, from screened to unscreened magnetic moments, and from normal metal to one in which only a single spin specie can conduct. Three main thrusts are being pursued: (i) Mott transitions in transition metal oxides, (ii) magnetism in half-metallic compounds, and (iii) large volume-collapse transitions in f-band metals.

  9. Solubility Behavior and Phase Stability of Transition Metal Oxides in Alkaline Hydrothermal Environments

    SciTech Connect (OSTI)

    S.E. Ziemniak

    2000-05-18T23:59:59.000Z

    The solubility behavior of transition metal oxides in high temperature water is interpreted by recognizing three types of chemical reaction equilibria: metal oxide hydration/dehydration, metal oxide dissolution and metal ion hydroxocomplex formation. The equilibria are quantified using thermodynamic concepts and the thermochemical properties of the metal oxides/ions representative of the most common constituents of construction metal alloys, i.e., element shaving atomic numbers between Z = 22 (Ti) and Z = 30 (Zn), are summarized on the basis of metal oxide solubility studies conducted in the laboratory. Particular attention is devoted to the uncharged metal ion hydrocomplex, M{sup Z}(OH){sub Z}(aq), since its thermochemical properties define minimum solubilities of the metal oxide at a given temperature. Experimentally-extracted values of standard partial molal entropy (S{sup 0}) for the transition metal ion neutral hydroxocomplex are shown to be influenced by ligand field stabilization energies and complex symmetry.

  10. Electrochemical lithiation and delithiation for control of magnetic properties of nanoscale transition metal oxides

    E-Print Network [OSTI]

    Sivakumar, Vikram

    2008-01-01T23:59:59.000Z

    Transition metal oxides comprise a fascinating class of materials displaying a variety of magnetic and electronic properties, ranging from half-metallic ferromagnets like CrO2, ferrimagnetic semiconductors like Fey's, and ...

  11. Methane-to-Methanol Conversion by Gas-Phase Transition Metal Oxide Cations: Experiment and Theory

    E-Print Network [OSTI]

    Metz, Ricardo B.

    Methane-to-Methanol Conversion by Gas-Phase Transition Metal Oxide Cations: Experiment and Theory-phase transition metal oxide cations can convert methane to methanol. Methane activation by MO+ is discussed such as methanol has attracted great experimental and theoretical interest due to its importance as an industrial

  12. Transition metal-catalyzed oxidation of atmospheric sulfur: Global implications for the sulfur budget

    E-Print Network [OSTI]

    Alexander, Becky

    processes, volca- noes) or produced within the atmosphere by oxidation of re- duced sulfur speciesTransition metal-catalyzed oxidation of atmospheric sulfur: Global implications for the sulfur importance of sulfate production by Fe(III)- and Mn(II)-catalyzed oxidation of S(IV) by O2. We scale

  13. TRANSITION DE MOTT METAL-INSULATOR TRANSITIONS

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    TRANSITION DE MOTT METAL-INSULATOR TRANSITIONS IN TRANSITION METAL OXIDES by D. B. McWHAN, A. MENTH oxydes de metaux de transition on observe une transition d'isolant a metal puis de metal a isolant de type Mott lorsque l'on augmentelenombre d'electrons d. Danslesysthe(V1-~Cr~)203une transition de Mott

  14. Transition Metal Dopants Essential for Producing Ferromagnetism...

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

    Metal Dopants Essential for Producing Ferromagnetism in Metal Oxide Nanoparticles. Transition Metal Dopants Essential for Producing Ferromagnetism in Metal Oxide Nanoparticles....

  15. Band gap tuning in transition metal oxides by site-specific substitution

    DOE Patents [OSTI]

    Lee, Ho Nyung; Chisholm, Jr., Matthew F; Jellison, Jr., Gerald Earle; Singh, David J; Choi, Woo Seok

    2013-12-24T23:59:59.000Z

    A transition metal oxide insulator composition having a tuned band gap includes a transition metal oxide having a perovskite or a perovskite-like crystalline structure. The transition metal oxide includes at least one first element selected form the group of Bi, Ca, Ba, Sr, Li, Na, Mg, K, Pb, and Pr; and at least one second element selected from the group of Ti, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Rh, Hf, Ta, W, Re, Os, Ir, and Pt. At least one correlated insulator is integrated into the crystalline structure, including REMO.sub.3, wherein RE is at least one Rare Earth element, and wherein M is at least one element selected from the group of Co, V, Cr, Ni, Mn, and Fe. The composition is characterized by a band gap of less of 4.5 eV.

  16. Structure formation upon reactive direct current magnetron sputtering of transition metal oxide films

    SciTech Connect (OSTI)

    Ngaruiya, J.M.; Kappertz, O.; Mohamed, S.H.; Wuttig, M. [I. Physikalisches Institut der RWTH Aachen, D-52056 Aachen, Germany and Jomo Kenyatta University of Agriculture and Technology, Box 62000 Nairobi (Kenya); I. Physikalisches Institut der RWTH Aachen, D-52056 Aachen (Germany)

    2004-08-02T23:59:59.000Z

    A comparative study of reactive direct current magnetron sputtering for different transition metal oxides reveals crystalline films at room temperature for group 4 and amorphous films for groups 5 and 6. This observation cannot be explained by the known growth laws and is attributed to the impact of energetic particles, originating from the oxidized target, on the growing film. This scenario is supported by measured target characteristics, the evolution of deposition stress of the films, and the observed backsputtering.

  17. Correlation effects in (111) bilayers of perovskite transition-metal oxides

    SciTech Connect (OSTI)

    Okamoto, Satoshi [ORNL] [ORNL; Zhu, Wenguang [University of Science and Technology of China] [University of Science and Technology of China; Nomura, Yusuke [University of Tokyo, Japan] [University of Tokyo, Japan; Arita, R. [University of Tokyo, Japan] [University of Tokyo, Japan; Xiao, Di [Carnegie Mellon University (CMU)] [Carnegie Mellon University (CMU); Nagaosa, Naoto [University of Tokyo, Japan] [University of Tokyo, Japan

    2014-01-01T23:59:59.000Z

    We investigate the correlation-induced Mott, magnetic, and topological phase transitions in artificial (111) bilayers of perovskite transition-metal oxides LaAuO3 and SrIrO3 for which the previous density-functional theory calculations predicted topological insulating states. Using the dynamical-mean-field theory with realistic band structures and Coulomb interactions, LaAuO3 bilayer is shown to be far away from a Mott insulating regime, and a topological-insulating state is robust. On the other hand, SrIrO3 bilayer is on the verge of an orbital-selective topological Mott transition and turns to a trivial insulator by an antiferromagnetic ordering. Oxide bilayers thus provide a novel class of topological materials for which the interplay between the spin-orbit coupling and electron-electron interactions is a fundamental ingredient.

  18. Synthesis and characterization of nanostructured transition metal oxides for energy storage devices

    E-Print Network [OSTI]

    Kim, Jong Woung

    2012-01-01T23:59:59.000Z

    Figure 1.1. Ragone plot of various energy storage systems [metal oxides for energy storage devices A dissertationmetal oxides for energy storage devices by Jong Woung Kim

  19. Synthesis and structural, magnetic, thermal, and transport properties of several transition metal oxides and aresnides

    SciTech Connect (OSTI)

    Das, Supriyo

    2010-05-16T23:59:59.000Z

    Oxide compounds containing the transition metal vanadium (V) have attracted a lot of attention in the field of condensed matter physics owing to their exhibition of interesting properties including metal-insulator transitons, structural transitions, ferromagnetic and antiferromagnetic orderings, and heavy fermion behavior. Binary vanadium oxides V{sub n}O{sub 2n-1} where 2 {le} n {le} 9 have triclinic structures and exhibit metal-insulator and antiferromagnetic transitions. The only exception is V{sub 7}O{sub 13} which remains metallic down to 4 K. The ternary vanadium oxide LiV{sub 2}O{sub 4} has the normal spinel structure, is metallic, does not undergo magnetic ordering and exhibits heavy fermion behavior below 10 K. CaV{sub 2}O{sub 4} has an orthorhombic structure with the vanadium spins forming zigzag chains and has been suggested to be a model system to study the gapless chiral phase. These provide great motivation for further investigation of some known vanadium compounds as well as to explore new vanadium compounds in search of new physics. This thesis consists, in part, of experimental studies involving sample preparation and magnetic, transport, thermal, and x-ray measurements on some strongly correlated eletron systems containing the transition metal vanadium. The compounds studied are LiV{sub 2}O{sub 4}, YV{sub 4}O{sub 8}, and YbV{sub 4}O{sub 8}. The recent discovery of superconductivity in RFeAsO{sub 1-x}F{sub x} (R = La, Ce, Pr, Gd, Tb, Dy, Sm, and Nd), and AFe{sub 2}As{sub 2} (A = Ba, Sr, Ca, and Eu) doped with K, Na, or Cs at the A site with relatively high T{sub c} has sparked tremendous activities in the condensed matter physics community and a renewed interest in the area of superconductivity as occurred following the discovery of the layered cuprate high T{sub c} superconductors in 1986. To discover more superconductors with hopefully higher T{sub c}'s, it is extremely important to investigate compounds having crystal structures related to the compounds showing high T{sub c} superconductivity. Along with the vanadium oxide compounds described before, this thesis describes our investigations of magnetic, structural, thermal and transport properties of EuPd{sub 2}Sb{sub 2} single crystals which have a crystal structure closely related to the AFe{sub 2}As{sub 2} compounds and also a study of the reaction kinetics of the formation of LaFeAsO{sub 1-x}F{sub x}.

  20. Finding Room for Improvement in Transition Metal Oxides Cathodes for Lithium-ion Batteries

    E-Print Network [OSTI]

    Kam, Kinson

    2012-01-01T23:59:59.000Z

    Metal Oxides Cathodes for Lithium-ion Batteries Kinson C.storage using rechargeable lithium-ion batteries has become

  1. Electrical conductivity in oxygen-deficient phases of transition metal oxides from first-principles calculations.

    SciTech Connect (OSTI)

    Bondi, Robert James; Desjarlais, Michael Paul; Thompson, Aidan Patrick; Brennecka, Geoffrey L.; Marinella, Matthew

    2013-09-01T23:59:59.000Z

    Density-functional theory calculations, ab-initio molecular dynamics, and the Kubo-Greenwood formula are applied to predict electrical conductivity in Ta2Ox (0x5) as a function of composition, phase, and temperature, where additional focus is given to various oxidation states of the O monovacancy (VOn; n=0,1+,2+). Our calculations of DC conductivity at 300K agree well with experimental measurements taken on Ta2Ox thin films and bulk Ta2O5 powder-sintered pellets, although simulation accuracy can be improved for the most insulating, stoichiometric compositions. Our conductivity calculations and further interrogation of the O-deficient Ta2O5 electronic structure provide further theoretical basis to substantiate VO0 as a donor dopant in Ta2O5 and other metal oxides. Furthermore, this dopant-like behavior appears specific to neutral VO cases in both Ta2O5 and TiO2 and was not observed in other oxidation states. This suggests that reduction and oxidation reactions may effectively act as donor activation and deactivation mechanisms, respectively, for VO0 in transition metal oxides.

  2. Stoichiometry determined exchange interactions in amorphous ternary transition metal oxides: Theory and experiment

    SciTech Connect (OSTI)

    Hu, Shu-jun; Yan, Shi-shen, E-mail: shishenyan@sdu.edu.cn; Zhang, Yun-peng; Zhao, Ming-wen; Kang, Shi-shou; Mei, Liang-mo [School of Physics, National Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong 250100 (China)

    2014-07-28T23:59:59.000Z

    Amorphous transition metal oxides exhibit exotic transport and magnetic properties, while the absence of periodic structure has long been a major obstacle for the understanding of their electronic structure and exchange interaction. In this paper, we have formulated a theoretical approach, which combines the melt-quench approach and the spin dynamic Monte-Carlo simulations, and based on it, we explored amorphous Co{sub 0.5}Zn{sub 0.5}O{sub 1?y} ternary transition metal oxides. Our theoretical results reveal that the microstructure, the magnetic properties, and the exchange interactions of Co{sub 0.5}Zn{sub 0.5}O{sub 1?y} are strongly determined by the oxygen stoichiometry. In the oxygen-deficient sample (y?>?0), we have observed the long-range ferromagnetic spin ordering which is associated with the non-stoichiometric cobalt-rich region rather than metallic clusters. On the other hand, the microstructure of stoichiometric sample takes the form of continuous random networks, and no long-range ferromagnetism has been observed in it. Magnetization characterization of experimental synthesized Co{sub 0.61}Zn{sub 0.39}O{sub 1?y} films verifies the relation between the spin ordering and the oxygen stoichiometry. Furthermore, the temperature dependence of electrical transport shows a typical feature of semiconductors, in agreement with our theoretical results.

  3. Hydrocracking and hydroisomerization of long-chain alkanes and polyolefins over metal-promoted anion-modified transition metal oxides

    SciTech Connect (OSTI)

    Venkatesh, Koppampatti R.; Hu, Jianli; Tierney, John W.; Wender, Irving

    1996-12-01T23:59:59.000Z

    A method is described for cracking a feedstock by contacting the feedstock with a metal-promoted anion-modified metal oxide catalyst in the presence of hydrogen gas. The metal oxide of the catalyst is one or more of ZrO{sub 2}, HfO{sub 2}, TiO{sub 2} and SnO{sub 2}, and the feedstock is principally chains of at least 20 carbon atoms. The metal-promoted anion-modified metal oxide catalyst contains one or more of Pt, Ni, Pd, Rh, Ir, Ru, (Mn and Fe) or mixtures of them present between about 0.2% to about 15% by weight of the catalyst. The metal-promoted anion-modified metal oxide catalyst contains one or more of SO{sub 4}, WO{sub 3}, or mixtures of them present between about 0.5% to about 20% by weight of the catalyst.

  4. Superconductors and Complex Transition Metal Oxides for Tunable THz Plasmonic Metamaterials

    SciTech Connect (OSTI)

    Singh, Ranjan [Los Alamos National Laboratory; Xiong, Jie [Los Alamos National Laboratory; Azad, Md A. [Los Alamos National Laboratory; Yang, Hao [Los Alamos National Laboratory; Trugman, Stuart A. [Los Alamos National Laboratory; Jia, Quanxi [Los Alamos National Laboratory; Taylor, Antoinette [Los Alamos National Laboratory; Chen, Houtong [Los Alamos National Laboratory

    2012-07-13T23:59:59.000Z

    The outline of this presentation are: (1) Motivation - Non-tunability of metal metamaterials; (2) Superconductors for temperature tunable metamaterials; (3) Ultrafast optical switching in superconductor metamaterials; (4) Controlling the conductivity with infrared pump beam; (5) Complex metal oxides as active substrates - Strontium Titanate; and (6) Conclusion. Conclusions are: (1) High Tc superconductors good for tunable and ultrafast metamaterials; (2) Large frequency and amplitude tunability in ultrathin superconductor films; (3) Such tunable properties cannot be accessed using metals; (4) Complex metal oxides can be used as active substrates - large tunability; (5) Complex oxides fail to address the issue of radiation losses in THz metamaterials.

  5. Interface engineering of quantum Hall effects in digital transition metal oxide heterostructures

    SciTech Connect (OSTI)

    Xiao, Di [ORNL; Zhu, Wenguang [University of Tennessee, Knoxville (UTK); Ran, Ying [Boston College, Chestnut Hill; Nagaosa, Naoto [University of Tokyo, Tokyo, Japan; Okamoto, Satoshi [ORNL

    2011-01-01T23:59:59.000Z

    Topological insulators (TIs) are characterized by a non-trivial band topology driven by the spin-orbit coupling. To fully explore the fundamental science and application of TIs, material realization is indispensable. Here we predict, based on tight-binding modeling and first-principles calculations, that bilayers of perovskite-type transition-metal oxides grown along the [111] crystallographic axis are potential candidates for two-dimensional TIs. The topological band structure of these materials can be fine-tuned by changing dopant ions, substrates and external gate voltages. We predict that LaAuO$_3$ bilayers have a topologically non-trivial energy gap of about 0.15~eV, which is sufficiently large to realize the quantum spin Hall effect at room temperature. Intriguing phenomena, such as fractional quantum Hall effect, associated with the nearly flat topologically non-trivial bands found in $e_g$ systems are also discussed.

  6. Chemistry of Sulfur Oxides on Transition Metals. II. Thermodynamics of Sulfur Oxides on Platinum(111)

    E-Print Network [OSTI]

    Lin, Xi

    J/mol from temperature-programmed desorption (TPD) experiments.4 Having some energetic data or, moreover, having substantial data on the thermodynamics of adsorption and interconversion of sulfur oxide species obtained several new vibrational features by pretreating the Pt(111) surface with the gas-phase oxygen

  7. Disorder induced semiconductor to metal transition and modifications of grain boundaries in nanocrystalline zinc oxide thin film

    SciTech Connect (OSTI)

    Singh, Fouran; Kumar, Vinod [Materials Science Group, Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Chaudhary, Babloo [Centre of Excellence in Material Sciences and Nanomaterials, Z. H. College of Engineering and Technology, Aligarh Muslim University, Aligarh, U.P. 202001 (India); Singh, R. G. [Department of Electronic Science, Maharaja Agrasen College, University of Delhi, New Delhi 110096 (India); Kumar, Sanjeev [Materials Science Group, Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Department of Electronic Science, University of Delhi South Campus, New Delhi 110023 (India); Kapoor, A. [Department of Electronic Science, University of Delhi South Campus, New Delhi 110023 (India)

    2012-10-01T23:59:59.000Z

    This paper report on the disorder induced semiconductor to metal transition (SMT) and modifications of grain boundaries in nanocrystalline zinc oxide thin film. Disorder is induced using energetic ion irradiation. It eliminates the possibility of impurities induced transition. However, it is revealed that some critical concentration of defects is needed for inducing such kind of SMT at certain critical temperature. Above room temperature, the current-voltage characteristics in reverse bias attributes some interesting phenomenon, such as electric field induced charge transfer, charge trapping, and diffusion of defects. The transition is explained by the defects induced disorder and strain in ZnO crystallites created by high density of electronic excitations.

  8. Improved layered mixed transition metal oxides for Li-ion batteries

    SciTech Connect (OSTI)

    Doeff, Marca M.; Conry, Thomas; Wilcox, James

    2010-03-05T23:59:59.000Z

    Recent work in our laboratory has been directed towards development of mixed layered transition metal oxides with general composition Li[Ni, Co, M, Mn]O2 (M=Al, Ti) for Li ion battery cathodes. Compounds such as Li[Ni1/3Co1/3Mn1/3]O2 (often called NMCs) are currently being commercialized for use in consumer electronic batteries, but the high cobalt content makes them too expensive for vehicular applications such as electric vehicles (EV), plug-in hybrid electric vehicles (PHEVs), or hybrid electric vehicles (HEVs). To reduce materials costs, we have explored partial or full substitution of Co with Al, Ti, and Fe. Fe substitution generally decreases capacity and results in poorer rate and cycling behavior. Interestingly, low levels of substitution with Al or Ti improve aspects of performance with minimal impact on energy densities, for some formulations. High levels of Al substitution compromise specific capacity, however, so further improvements require that the Ni and Mn content be increased and Co correspondingly decreased. Low levels of Al or Ti substitution can then be used offset negative effects induced by the higher Ni content. The structural and electrochemical characterization of substituted NMCs is presented in this paper.

  9. New sol-gel synthetic route to transition and main-group metal oxide aerogels using inorganic salt precursors

    SciTech Connect (OSTI)

    Gash, A E; Tillotson, T M; Satcher Jr, J H; Hrubesh, L W; Simpson, R L

    2000-09-12T23:59:59.000Z

    We have developed a new sol-gel route to synthesize several transition and main-group metal oxide aerogels. The approach is straightforward, inexpensive, versatile, and it produces monolithic microporous materials with high surface areas. Specifically, we report the use of epoxides as gelation agents for the sol-gel synthesis of chromia aerogels and xerogels from simple Cr(III) inorganic salts. The dependence of both gel formation and its rate was studied by varying the solvent used, the Cr(III) precursor salt, the epoxide/Cr(III) ratio, as well as the type of epoxide employed. All of these variables were shown to affect the rate of gel formation and provide a convenient control of this parameter. Dried chromia aerogels were characterized by high-resolution transmission electron microscopy (HRTEM) and nitrogen adsorption/desorption analyses, results of which will be presented. Our studies have shown that rigid monolithic gels can be prepared from many different metal ions salts, provided the formal oxidation state of the metal ion is greater than or equal to +3. Conversely, when di-valent transition metal salts are used precipitated solids are the products.

  10. Metal oxide films on metal

    DOE Patents [OSTI]

    Wu, Xin D. (Los Alamos, NM); Tiwari, Prabhat (Los Alamos, NM)

    1995-01-01T23:59:59.000Z

    A structure including a thin film of a conductive alkaline earth metal oxide selected from the group consisting of strontium ruthenium trioxide, calcium ruthenium trioxide, barium ruthenium trioxide, lanthanum-strontium cobalt oxide or mixed alkaline earth ruthenium trioxides thereof upon a thin film of a noble metal such as platinum is provided.

  11. Oxidation of Methanol on 2nd and 3rd Row Group VIII Transition Metals (Pt, Ir, Os, Pd, Rh, and Ru): Application to Direct Methanol

    E-Print Network [OSTI]

    Goddard III, William A.

    Oxidation of Methanol on 2nd and 3rd Row Group VIII Transition Metals (Pt, Ir, Os, Pd, Rh, and Ru): Application to Direct Methanol Fuel Cells Jeremy Kua and William A. Goddard III* Contribution from functional theory (B3LYP)], we calculated the 13 most likely intermediate species for methanol oxidation

  12. Transition metal sulfide loaded catalyst

    DOE Patents [OSTI]

    Maroni, V.A.; Iton, L.E.; Pasterczyk, J.W.; Winterer, M.; Krause, T.R.

    1994-04-26T23:59:59.000Z

    A zeolite-based catalyst is described for activation and conversion of methane. A zeolite support includes a transition metal (Mo, Cr or W) sulfide disposed within the micropores of the zeolite. The catalyst allows activation and conversion of methane to C[sub 2]+ hydrocarbons in a reducing atmosphere, thereby avoiding formation of oxides of carbon.

  13. Fluorescence-based detection methodologies for nitric oxide using transition metal scaffolds

    E-Print Network [OSTI]

    Hilderbrand, Scott A. (Scott Alan), 1976-

    2004-01-01T23:59:59.000Z

    Chapter 1. Fluorescence-Based Detection Methodologies for Nitric Oxide: A Review. Chapter 2. Cobalt Chemistry with Mixed Aminotroponimine Salicylaldimine Ligands: Synthesis, Characterization, and Nitric Oxide Reactivity. ...

  14. Functionalized Silicone Nanospheres: Synthesis, Transition Metal...

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

    Functionalized Silicone Nanospheres: Synthesis, Transition Metal Immobilization, and Catalytic Applications. Functionalized Silicone Nanospheres: Synthesis, Transition Metal...

  15. Finding Room for Improvement in Transition Metal Oxides Cathodes for Lithium-ion Batteries

    E-Print Network [OSTI]

    Kam, Kinson

    2012-01-01T23:59:59.000Z

    Oxides Cathodes for Lithium-ion Batteries Kinson C. Kam andusing rechargeable lithium-ion batteries has become an

  16. Methane Activation by Transition-Metal Oxides, MOx (M ) Cr, Mo, W; x ) 1, 2, 3) Xin Xu,# Francesco Faglioni, and William A. Goddard, III*

    E-Print Network [OSTI]

    Goddard III, William A.

    The efficient catalytic conversion of methane to petrochemical feedstocks and liquid fuels is a great technicalMethane Activation by Transition-Metal Oxides, MOx (M ) Cr, Mo, W; x ) 1, 2, 3) Xin Xu,# Francesco, 2002 Recent experiments on the dehydrogenation-aromatization of methane (DHAM) to form benzene using

  17. Mechanism of oxygen reduction reaction on transition metal oxide catalysts for high temperature fuel cells

    E-Print Network [OSTI]

    La O', Gerardo Jose Cordova

    2008-01-01T23:59:59.000Z

    The solid oxide fuel cell (SOFC) with its high energy conversion efficiency, low emissions, silent operation and its ability to utilize commercial fuels has the potential to create a large impact on the energy landscape. ...

  18. The detection of nitric oxide and its reactivity with transition metal thiolate complexes

    E-Print Network [OSTI]

    Tennyson, Andrew Gregory

    2008-01-01T23:59:59.000Z

    Nitric oxide (NO) is a molecule that is essential for life and regulates both beneficial and harmful processes. Because this gaseous radical influences many aspects of health and disease, we wish to explore the relationship ...

  19. Interplay between electronic structure and catalytic activity in transition metal oxide model system

    E-Print Network [OSTI]

    Suntivich, Jin

    2012-01-01T23:59:59.000Z

    The efficiency of many energy storage and conversion technologies, such as hydrogen fuel cells, rechargeable metal-air batteries, and hydrogen production from water splitting, is limited by the slow kinetics of the oxygen ...

  20. Ab initio screening of lithium diffusion rates in transition metal oxide cathodes for lithium ion batteries

    E-Print Network [OSTI]

    Moore, Charles J. (Charles Jacob)

    2012-01-01T23:59:59.000Z

    A screening metric for diffusion limitations in lithium ion battery cathodes is derived using transition state theory and common materials properties. The metric relies on net activation barrier for lithium diffusion. ...

  1. Transition Metal Switchable Mirror

    ScienceCinema (OSTI)

    None

    2010-01-08T23:59:59.000Z

    The switchable-mirrors technology was developed by Tom Richardson and Jonathan Slack of Berkeley Lab's Environmental Energy Technologies Division. By using transition metals rather than the rare earth metals used in the first metal-hydride switchable mirrors, Richardson and Slack were able to lower the cost and simplify the manufacturing process. Energy performance is improved as well, because the new windows can reflect or transmit both visible and infrared light. Besides windows for offices and homes, possible applications include automobile sunroofs, signs and displays, aircraft windows, and spacecraft.

  2. Transition Metal Switchable Mirror

    ScienceCinema (OSTI)

    None

    2013-05-29T23:59:59.000Z

    The switchable-mirrors technology was developed by Tom Richardson and Jonathan Slack of Berkeley Lab's Environmental Energy Technologies Division. By using transition metals rather than the rare earth metals used in the first metal-hydride switchable mirrors, Richardson and Slack were able to lower the cost and simplify the manufacturing process. Energy performance is improved as well, because the new windows can reflect or transmit both visible and infrared light. Besides windows for offices and homes, possible applications include automobile sunroofs, signs and displays, aircraft windows, and spacecraft. More information at: http://windows.lbl.gov/materials/chromogenics/default.htm

  3. Transition Metal Switchable Mirror

    SciTech Connect (OSTI)

    None

    2009-01-01T23:59:59.000Z

    The switchable-mirrors technology was developed by Tom Richardson and Jonathan Slack of Berkeley Lab's Environmental Energy Technologies Division. By using transition metals rather than the rare earth metals used in the first metal-hydride switchable mirrors, Richardson and Slack were able to lower the cost and simplify the manufacturing process. Energy performance is improved as well, because the new windows can reflect or transmit both visible and infrared light. Besides windows for offices and homes, possible applications include automobile sunroofs, signs and displays, aircraft windows, and spacecraft. More information at: http://windows.lbl.gov/materials/chromogenics/default.htm

  4. Transition Metal Switchable Mirror

    SciTech Connect (OSTI)

    2009-08-21T23:59:59.000Z

    The switchable-mirrors technology was developed by Tom Richardson and Jonathan Slack of Berkeley Lab's Environmental Energy Technologies Division. By using transition metals rather than the rare earth metals used in the first metal-hydride switchable mirrors, Richardson and Slack were able to lower the cost and simplify the manufacturing process. Energy performance is improved as well, because the new windows can reflect or transmit both visible and infrared light. Besides windows for offices and homes, possible applications include automobile sunroofs, signs and displays, aircraft windows, and spacecraft.

  5. The design of new ligands and transition metal compounds for the oxidation of organic compounds

    E-Print Network [OSTI]

    Grill, Joseph Michael

    2009-06-02T23:59:59.000Z

    ........................................................................................... 108 APPENDIX B............................................................................................ 215 APPENDIX C............................................................................................ 225 VITA..., oxidation of manganese (III) to manganese (V) occurs, followed by addition of an olefin to form a C-O bond and a carbon radical. Collapse of the radical species t 12 then gives the epoxide (Scheme 1.8). 38 This mechanism allows for the possibility...

  6. High Performance Ceramic Interconnect Material for Solid Oxide Fuel Cells (SOFCs): Ca- and Transition Metal-doped Yttrium Chromite

    SciTech Connect (OSTI)

    Yoon, Kyung J.; Stevenson, Jeffry W.; Marina, Olga A.

    2011-10-15T23:59:59.000Z

    The effect of transition metal substitution on thermal and electrical properties of Ca-doped yttrium chromite was investigated in relation to use as a ceramic interconnect in high temperature solid oxide fuel cells (SOFCs). 10 at% Co, 4 at% Ni, and 1 at% Cu substitution on B-site of 20 at% Ca-doped yttrium chromite led to a close match of thermal expansion coefficient (TEC) with that of 8 mol% yttria-stabilized zirconia (YSZ), and a single phase Y0.8Ca0.2Cr0.85Co0.1Ni0.04Cu0.01O3 remained stable between 25 and 1100 degree C over a wide oxygen partial pressure range. Doping with Cu significantly facilitated densification of yttrium chromite. Ni dopant improved both electrical conductivity and dimensional stability in reducing environments, likely through diminishing the oxygen vacancy formation. Substitution with Co substantially enhanced electrical conductivity in oxidizing atmosphere, which was attributed to an increase in charge carrier density and hopping mobility. Electrical conductivity of Y0.8Ca0.2Cr0.85Co0.1Ni0.04Cu0.01O3 at 900 degree C is 57 S/cm in air and 11 S/cm in fuel (pO2=5×10^-17 atm) environments. Chemical compatibility of doped yttrium chromite with other cell components was verified at the processing temperatures. Based on the chemical and dimensional stability, sinterability, and thermal and electrical properties, Y0.8Ca0.2Cr0.85Co0.1Ni0.04Cu0.01O3 is suggested as a promising SOFC ceramic interconnect to potentially overcome technical limitations of conventional acceptor-doped lanthanum chromites.

  7. Calixarene supported transition metal clusters 

    E-Print Network [OSTI]

    Taylor, Stephanie Merac

    2013-06-29T23:59:59.000Z

    This thesis describes a series of calix[n]arene polynuclear transition metal and lanthanide complexes. Calix[4]arenes possess lower-rim polyphenolic pockets that are ideal for the complexation of various transition metal ...

  8. Oxidation energies of transition metal oxides within the GGA+U framework Lei Wang, Thomas Maxisch, and Gerbrand Ceder*

    E-Print Network [OSTI]

    Ceder, Gerbrand

    is computed using the generalized gradient approach GGA and GGA+U methods. Two substantial contributions, combustion, metal refining, electrochemical energy generation and storage, photosynthesis, and metabolism and generalized gradient approxima- tion GGA , two standard approximations to density func- tional theory DFT

  9. Method for dry etching of transition metals

    DOE Patents [OSTI]

    Ashby, Carol I. H. (Edgewood, NM); Baca, Albert G. (Albuquerque, NM); Esherick, Peter (Albuquerque, NM); Parmeter, John E. (Albuquerque, NM); Rieger, Dennis J. (Tijeras, NM); Shul, Randy J. (Albuquerque, NM)

    1998-01-01T23:59:59.000Z

    A method for dry etching of transition metals. The method for dry etching of a transition metal (or a transition metal alloy such as a silicide) on a substrate comprises providing at least one nitrogen- or phosphorous-containing .pi.-acceptor ligand in proximity to the transition metal, and etching the transition metal to form a volatile transition metal/.pi.-acceptor ligand complex. The dry etching may be performed in a plasma etching system such as a reactive ion etching (RIE) system, a downstream plasma etching system (i.e. a plasma afterglow), a chemically-assisted ion beam etching (CAIBE) system or the like. The dry etching may also be performed by generating the .pi.-acceptor ligands directly from a ligand source gas (e.g. nitrosyl ligands generated from nitric oxide), or from contact with energized particles such as photons, electrons, ions, atoms, or molecules. In some preferred embodiments of the present invention, an intermediary reactant species such as carbonyl or a halide ligand is used for an initial chemical reaction with the transition metal, with the intermediary reactant species being replaced at least in part by the .pi.-acceptor ligand for forming the volatile transition metal/.pi.-acceptor ligand complex.

  10. STUDY MAGNETIC EXCITATIONS IN DOPED TRANSITION METAL OXIDES USING INELASTIC NEUTRON SCATTERING

    SciTech Connect (OSTI)

    Dai, Pengcheng

    2014-02-18T23:59:59.000Z

    Understanding the interplay between magnetism and superconductivity continues to be a “hot” topic in modern condensed matter physics. The discovery of high-temperature superconductivity in iron-based materials in 2008 provided an unique opportunity to compare and contrast these materials with traditional high-Tc copper oxide superconductors. Neutron scattering plays an important role in determining the dynamical spin properties in these materials. This proposal is a continuation of previous DOE supported proposal. This report summarizes the final progress we have made over from May 2005 till Aug. 2013. Overall, we continue to carry out extensive neutron scattering experiments on Fe-based materials, focusing on understanding their magnetic properties. In addition, we have established a materials laboratory at UT that has allowed us to grow these superconductors. Because neutron scattering typically demands a large amount of samples, by growing these materials in our own laboratory, we can now pursuit neutron scattering experiments over the entire electronic phase diagram, focusing on regions of interests. The material synthesis laboratory at UT was established entirely with the support of DOE funding. This not only allowed us to carry out neutron scattering experiments, but also permit us to provide samples to other US/International collaborators for studying these materials.

  11. Extracting metals directly from metal oxides

    DOE Patents [OSTI]

    Wai, C.M.; Smart, N.G.; Phelps, C.

    1997-02-25T23:59:59.000Z

    A method of extracting metals directly from metal oxides by exposing the oxide to a supercritical fluid solvent containing a chelating agent is described. Preferably, the metal is an actinide or a lanthanide. More preferably, the metal is uranium, thorium or plutonium. The chelating agent forms chelates that are soluble in the supercritical fluid, thereby allowing direct removal of the metal from the metal oxide. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is selected from the group consisting of {beta}-diketones, halogenated {beta}-diketones, phosphinic acids, halogenated phosphinic acids, carboxylic acids, halogenated carboxylic acids, and mixtures thereof. In especially preferred embodiments, at least one of the chelating agents is fluorinated. The method provides an environmentally benign process for removing metals from metal oxides without using acids or biologically harmful solvents. The chelate and supercritical fluid can be regenerated, and the metal recovered, to provide an economic, efficient process. 4 figs.

  12. Extracting metals directly from metal oxides

    DOE Patents [OSTI]

    Wai, Chien M. (Moscow, ID); Smart, Neil G. (Moscow, ID); Phelps, Cindy (Moscow, ID)

    1997-01-01T23:59:59.000Z

    A method of extracting metals directly from metal oxides by exposing the oxide to a supercritical fluid solvent containing a chelating agent is described. Preferably, the metal is an actinide or a lanthanide. More preferably, the metal is uranium, thorium or plutonium. The chelating agent forms chelates that are soluble in the supercritical fluid, thereby allowing direct removal of the metal from the metal oxide. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is selected from the group consisting of .beta.-diketones, halogenated .beta.-diketones, phosphinic acids, halogenated phosphinic acids, carboxylic acids, halogenated carboxylic acids, and mixtures thereof. In especially preferred embodiments, at least one of the chelating agents is fluorinated. The method provides an environmentally benign process for removing metals from metal oxides without using acids or biologically harmful solvents. The chelate and supercritical fluid can be regenerated, and the metal recovered, to provide an economic, efficient process.

  13. Lithium metal oxide electrodes for lithium batteries

    DOE Patents [OSTI]

    Thackeray, Michael M. (Naperville, IL); Kim, Jeom-Soo (Naperville, IL); Johnson, Christopher S. (Naperville, IL)

    2008-01-01T23:59:59.000Z

    An uncycled electrode for a non-aqueous lithium electrochemical cell including a lithium metal oxide having the formula Li.sub.(2+2x)/(2+x)M'.sub.2x/(2+x)M.sub.(2-2x)/(2+x)O.sub.2-.delta., in which 0.ltoreq.x<1 and .delta. is less than 0.2, and in which M is a non-lithium metal ion with an average trivalent oxidation state selected from two or more of the first row transition metals or lighter metal elements in the periodic table, and M' is one or more ions with an average tetravalent oxidation state selected from the first and second row transition metal elements and Sn. Methods of preconditioning the electrodes are disclosed as are electrochemical cells and batteries containing the electrodes.

  14. Ballistic performance comparison of monolayer transition metal dichalcogenide MX{sub 2} (M = Mo, W; X = S, Se, Te) metal-oxide-semiconductor field effect transistors

    SciTech Connect (OSTI)

    Chang, Jiwon; Register, Leonard F.; Banerjee, Sanjay K. [Microelectronics Research Center, The University of Texas at Austin, Austin, Texas 78758 (United States)

    2014-02-28T23:59:59.000Z

    We study the transport properties of monolayer MX{sub 2} (M?=?Mo, W; X?=?S, Se, Te) n- and p-channel metal-oxide-semiconductor field effect transistors (MOSFETs) using full-band ballistic non-equilibrium Green's function simulations with an atomistic tight-binding Hamiltonian with hopping potentials obtained from density functional theory. We discuss the subthreshold slope, drain-induced barrier lowering (DIBL), as well as gate-induced drain leakage (GIDL) for different monolayer MX{sub 2} MOSFETs. We also report the possibility of negative differential resistance behavior in the output characteristics of nanoscale monolayer MX{sub 2} MOSFETs.

  15. Lithium metal oxide electrodes for lithium batteries

    DOE Patents [OSTI]

    Thackeray, Michael M.; Johnson, Christopher S.; Amine, Khalil; Kang, Sun-Ho

    2010-06-08T23:59:59.000Z

    An uncycled preconditioned electrode for a non-aqueous lithium electrochemical cell including a lithium metal oxide having the formula xLi.sub.2-yH.sub.yO.xM'O.sub.2.(1-x)Li.sub.1-zH.sub.zMO.sub.2 in which 0metal ion with an average trivalent oxidation state selected from two or more of the first row transition metals or lighter metal elements in the periodic table, and M' is one or more ions with an average tetravalent oxidation state selected from the first and second row transition metal elements and Sn. The xLi.sub.2-yH.sub.y.xM'O.sub.2.(1-x)Li.sub.1-zH.sub.zMO.sub.2 material is prepared by preconditioning a precursor lithium metal oxide (i.e., xLi.sub.2M'O.sub.3.(1-x)LiMO.sub.2) with a proton-containing medium with a pH<7.0 containing an inorganic acid. Methods of preparing the electrodes are disclosed, as are electrochemical cells and batteries containing the electrodes.

  16. Magnetic Properties of Mesoporous and Nano-particulate Metal Oxides 

    E-Print Network [OSTI]

    Hill, Adrian H

    2009-01-01T23:59:59.000Z

    The magnetic properties of the first row transition metal oxides are wide and varied and have been studied extensively since the 1930’s. Observations that the magnetic properties of these material types change with the ...

  17. Metal oxide nanostructures with hierarchical morphology

    DOE Patents [OSTI]

    Ren, Zhifeng (Newton, MA); Lao, Jing Yu (Saline, MI); Banerjee, Debasish (Ann Arbor, MI)

    2007-11-13T23:59:59.000Z

    The present invention relates generally to metal oxide materials with varied symmetrical nanostructure morphologies. In particular, the present invention provides metal oxide materials comprising one or more metallic oxides with three-dimensionally ordered nanostructural morphologies, including hierarchical morphologies. The present invention also provides methods for producing such metal oxide materials.

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

    SciTech Connect (OSTI)

    Bitterwolf, Thomas E. [University of Idaho

    2014-12-09T23:59:59.000Z

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

  19. METAL OXIDE NANOPARTICLES

    SciTech Connect (OSTI)

    FERNANDEZ-GARCIA,M.; RODGRIGUEZ, J.A.

    2007-10-01T23:59:59.000Z

    This chapter covers the fundamental science, synthesis, characterization, physicochemical properties and applications of oxide nanomaterials. Explains fundamental aspects that determine the growth and behavior of these systems, briefly examines synthetic procedures using bottom-up and top-down fabrication technologies, discusses the sophisticated experimental techniques and state of the art theory results used to characterize the physico-chemical properties of oxide solids and describe the current knowledge concerning key oxide materials with important technological applications.

  20. Process for making transition metal nitride whiskers

    DOE Patents [OSTI]

    Bamberger, Carlos E. (Oak Ridge, TN)

    1989-01-01T23:59:59.000Z

    A process for making metal nitrides, particularly titanium nitride whiskers, using a cyanide salt as a reducing agent for a metal compound in the presence of an alkali metal oxide. Sodium cyanide, various titanates and titanium oxide mixed with sodium oxide react to provide titanium nitride whiskers that can be used as reinforcement to ceramic composites.

  1. Process for making transition metal nitride whiskers

    DOE Patents [OSTI]

    Bamberger, C.E.

    1988-04-12T23:59:59.000Z

    A process for making metal nitrides, particularly titanium nitride whiskers, using a cyanide salt as a reducing agent for a metal compound in the presence of an alkali metal oxide. Sodium cyanide, various titanates and titanium oxide mixed with sodium oxide react to provide titanium nitride whiskers that can be used as reinforcement to ceramic composites. 1 fig., 1 tab.

  2. Approximating Metal-Insulator Transitions

    E-Print Network [OSTI]

    C. Danieli; K. Rayanov; B. Pavlov; G. Martin; S. Flach

    2014-05-06T23:59:59.000Z

    We consider quantum wave propagation in one-dimensional quasiperiodic lattices. We propose an iterative construction of quasiperiodic potentials from sequences of potentials with increasing spatial period. At each finite iteration step the eigenstates reflect the properties of the limiting quasiperiodic potential properties up to a controlled maximum system size. We then observe approximate metal-insulator transitions (MIT) at the finite iteration steps. We also report evidence on mobility edges which are at variance to the celebrated Aubry-Andre model. The dynamics near the MIT shows a critical slowing down of the ballistic group velocity in the metallic phase similar to the divergence of the localization length in the insulating phase.

  3. Lithium metal reduction of plutonium oxide to produce plutonium metal

    DOE Patents [OSTI]

    Coops, Melvin S. (Livermore, CA)

    1992-01-01T23:59:59.000Z

    A method is described for the chemical reduction of plutonium oxides to plutonium metal by the use of pure lithium metal. Lithium metal is used to reduce plutonium oxide to alpha plutonium metal (alpha-Pu). The lithium oxide by-product is reclaimed by sublimation and converted to the chloride salt, and after electrolysis, is removed as lithium metal. Zinc may be used as a solvent metal to improve thermodynamics of the reduction reaction at lower temperatures. Lithium metal reduction enables plutonium oxide reduction without the production of huge quantities of CaO--CaCl.sub.2 residues normally produced in conventional direct oxide reduction processes.

  4. Preparation of uniform nanoparticles of ultra-high purity metal oxides, mixed metal oxides, metals, and metal alloys

    DOE Patents [OSTI]

    Woodfield, Brian F.; Liu, Shengfeng; Boerio-Goates, Juliana; Liu, Qingyuan; Smith, Stacey Janel

    2012-07-03T23:59:59.000Z

    In preferred embodiments, metal nanoparticles, mixed-metal (alloy) nanoparticles, metal oxide nanoparticles and mixed-metal oxide nanoparticles are provided. According to embodiments, the nanoparticles may possess narrow size distributions and high purities. In certain preferred embodiments, methods of preparing metal nanoparticles, mixed-metal nanoparticles, metal oxide nanoparticles and mixed-metal nanoparticles are provided. These methods may provide tight control of particle size, size distribution, and oxidation state. Other preferred embodiments relate to a precursor material that may be used to form nanoparticles. In addition, products prepared from such nanoparticles are disclosed.

  5. NANO - "Green" metal oxides ... | ornl.gov

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

    "Green" metal oxides ... Water and nano-sized particles isolated from trees, plants and algae are the ingredients of a new recipe for low-cost metal oxides that are widely used in...

  6. Synthesis of transition metal carbonitrides

    DOE Patents [OSTI]

    Munir, Zuhair A. R. (Davis, CA); Eslamloo-Grami, Maryam (Davis, CA)

    1994-01-01T23:59:59.000Z

    Transition metal carbonitrides (in particular, titanium carbonitride, TiC.sub.0.5 N.sub.0.5) are synthesized by a self-propagating reaction between the metal (e.g., titanium) and carbon in a nitrogen atmosphere. Complete conversion to the carbonitride phase is achieved with the addition of TiN as diluent and with a nitrogen pressure .gtoreq.0.6 MPa. Thermodynamic phase-stability calculations and experimental characterizations of quenched samples provided revealed that the mechanism of formation of the carbonitride is a two-step process. The first step involves the formation of the nonstoichiometric carbide, TiC.sub.0.5, and is followed by the formation of the product by the incorporation of nitrogen in the defect-structure carbide.

  7. Spectroscopic studies of metal growth on oxides

    E-Print Network [OSTI]

    Luo, Kai

    2000-01-01T23:59:59.000Z

    : Chemistry SPECTROSCOPIC STUDIES OF METAL GROWTH ON OXIDES A Thesis by KAI LUO Submitted to Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved as to style a d content by: avid W. Goodman.... , Jilin University, P. R. China Chair of Advisory Committee: Dr, David W. Goodman Metal/oxide chemistry and metal cluster growth on oxides are fundamental to our understanding of the catalytic activity and selectivity of metal catalysts, thus...

  8. Method for producing metal oxide nanoparticles

    DOE Patents [OSTI]

    Phillips, Jonathan (Santa Fe, NM); Mendoza, Daniel (Santa Fe, NM); Chen, Chun-Ku (Albuquerque, NM)

    2008-04-15T23:59:59.000Z

    Method for producing metal oxide nanoparticles. The method includes generating an aerosol of solid metallic microparticles, generating plasma with a plasma hot zone at a temperature sufficiently high to vaporize the microparticles into metal vapor, and directing the aerosol into the hot zone of the plasma. The microparticles vaporize in the hot zone into metal vapor. The metal vapor is directed away from the hot zone and into the cooler plasma afterglow where it oxidizes, cools and condenses to form solid metal oxide nanoparticles.

  9. Graphene physics and insulator-metal transition in compressed...

    Office of Scientific and Technical Information (OSTI)

    Graphene physics and insulator-metal transition in compressed hydrogen Citation Details Title: Graphene physics and insulator-metal transition in compressed hydrogen Authors:...

  10. Aromaticity and Antiaromaticity in Transition-Metal Systems....

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

    Aromaticity and Antiaromaticity in Transition-Metal Systems. Aromaticity and Antiaromaticity in Transition-Metal Systems. Abstract: Aromaticity is an important concept in chemistry...

  11. Binding Energy of dº Transition Metals to Alkenes By Wave...

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

    Energy of dº Transition Metals to Alkenes By Wave Function Theory and Density Functional Theory. Binding Energy of dº Transition Metals to Alkenes By Wave Function Theory...

  12. Effects of Transition Metals on the Grain Boundary Cohesion in...

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

    Transition Metals on the Grain Boundary Cohesion in Tungsten. Effects of Transition Metals on the Grain Boundary Cohesion in Tungsten. Abstract: We report on the effects of...

  13. Metal complexes of substituted Gable porphyrins as oxidation catalysts

    DOE Patents [OSTI]

    Lyons, J.E.; Ellis, P.E. Jr.; Wagner, R.W.

    1996-01-02T23:59:59.000Z

    Transition metal complexes of Gable porphyrins are disclosed having two porphyrin rings connected through a linking group, and having on the porphyrin rings electron-withdrawing groups, such as halogen, nitro or cyano. These complexes are useful as catalysts for the oxidation of organic compounds, e.g. alkanes.

  14. Metal complexes of substituted Gable porphyrins as oxidation catalysts

    DOE Patents [OSTI]

    Lyons, James E. (Wallingford, PA); Ellis, Jr., Paul E. (Downingtown, PA); Wagner, Richard W. (Murrysville, PA)

    1996-01-01T23:59:59.000Z

    Transition metal complexes of Gable porphyrins having two porphyrin rings connected through a linking group, and having on the porphyrin rings electron-withdrawing groups, such as halogen, nitro or cyano. These complexes are useful as catalysts for the oxidation of organic compounds, e.g. alkanes.

  15. Reduction of Metal Oxide to Metal using Ionic Liquids

    SciTech Connect (OSTI)

    Dr. Ramana Reddy

    2012-04-12T23:59:59.000Z

    A novel pathway for the high efficiency production of metal from metal oxide means of electrolysis in ionic liquids at low temperature was investigated. The main emphasis was to eliminate the use of carbon and high temperature application in the reduction of metal oxides to metals. The emphasis of this research was to produce metals such as Zn, and Pb that are normally produced by the application of very high temperatures. The reduction of zinc oxide to zinc and lead oxide to lead were investigated. This study involved three steps in accomplishing the final goal of reduction of metal oxide to metal using ionic liquids: 1) Dissolution of metal oxide in an ionic liquid, 2) Determination of reduction potential using cyclic voltammetry (CV) and 3) Reduction of the dissolved metal oxide. Ionic liquids provide additional advantage by offering a wide potential range for the deposition. In each and every step of the process, more than one process variable has been examined. Experimental results for electrochemical extraction of Zn from ZnO and Pb from PbO using eutectic mixtures of Urea ((NH2)2CO) and Choline chloride (HOC2H4N(CH3)3+Cl-) or (ChCl) in a molar ratio 2:1, varying voltage and temperatures were carried out. Fourier Transform Infra-Red (FTIR) spectroscopy studies of ionic liquids with and without metal oxide additions were conducted. FTIR and induction coupled plasma spectroscopy (ICPS) was used in the characterization of the metal oxide dissolved ionic liquid. Electrochemical experiments were conducted using EG&G potentiostat/galvanostat with three electrode cell systems. Cyclic voltammetry was used in the determination of reduction potentials for the deposition of metals. Chronoamperometric experiments were carried out in the potential range of -0.6V to -1.9V for lead and -1.4V to -1.9V for zinc. The deposits were characterized using XRD and SEM-EDS for phase, morphological and elemental analysis. The results showed that pure metal was deposited on the cathode. Successful extraction of metal from metal oxide dissolved in Urea/ChCl (2:1) was accomplished. The current efficiencies were relatively high in both the metal deposition processes with current efficiency greater than 86% for lead and 95% for zinc. This technology will advance the metal oxide reduction process by increasing the process efficiency and also eliminate the production of CO2 which makes this an environmentally benign technology for metal extraction.

  16. Nanocomposite of graphene and metal oxide materials

    DOE Patents [OSTI]

    Liu, Jun; Aksay, Ilhan A.; Choi, Daiwon; Wang, Donghai; Yang, Zhenguo

    2013-10-15T23:59:59.000Z

    Nanocomposite materials comprising a metal oxide bonded to at least one graphene material. The nanocomposite materials exhibit a specific capacity of at least twice that of the metal oxide material without the graphene at a charge/discharge rate greater than about 10 C.

  17. Nanocomposite of graphene and metal oxide materials

    DOE Patents [OSTI]

    Liu, Jun; Aksay, Ilhan A.; Choi, Daiwon; Wang, Donghai; Yang, Zhenguo

    2012-09-04T23:59:59.000Z

    Nanocomposite materials comprising a metal oxide bonded to at least one graphene material. The nanocomposite materials exhibit a specific capacity of at least twice that of the metal oxide material without the graphene at a charge/discharge rate greater than about 10C.

  18. Transition metal fluorides: from superconductors to multiferroics. 

    E-Print Network [OSTI]

    Drathen, Christina

    2013-06-29T23:59:59.000Z

    Transition metal fluorides represent an important family of complex solids displaying a variety of different properties and interesting phenomena. Despite their remarkable behaviour, these classes of materials have not ...

  19. Methods of producing adsorption media including a metal oxide

    DOE Patents [OSTI]

    Mann, Nicholas R; Tranter, Troy J

    2014-03-04T23:59:59.000Z

    Methods of producing a metal oxide are disclosed. The method comprises dissolving a metal salt in a reaction solvent to form a metal salt/reaction solvent solution. The metal salt is converted to a metal oxide and a caustic solution is added to the metal oxide/reaction solvent solution to adjust the pH of the metal oxide/reaction solvent solution to less than approximately 7.0. The metal oxide is precipitated and recovered. A method of producing adsorption media including the metal oxide is also disclosed, as is a precursor of an active component including particles of a metal oxide.

  20. Method of producing adherent metal oxide coatings on metallic surfaces

    DOE Patents [OSTI]

    Lane, Michael H. (Clifton Park, NY); Varrin, Jr., Robert D. (McLean, VA)

    2001-01-01T23:59:59.000Z

    Provided is a process of producing an adherent synthetic corrosion product (sludge) coating on metallic surfaces. The method involves a chemical reaction between a dry solid powder mixture of at least one reactive metal oxide with orthophosphoric acid to produce a coating in which the particles are bound together and the matrix is adherent to the metallic surface.

  1. Three-Electrode Metal Oxide Reduction Cell

    DOE Patents [OSTI]

    Dees, Dennis W. (Downers Grove, IL); Ackerman, John P. (Downers Grove, IL)

    2005-06-28T23:59:59.000Z

    A method of electrochemically reducing a metal oxide to the metal in an electrochemical cell is disclosed along with the cell. Each of the anode and cathode operate at their respective maximum reaction rates. An electrolyte and an anode at which oxygen can be evolved, and a cathode including a metal oxide to be reduced are included as is a third electrode with independent power supplies connecting the anode and the third electrode and the cathode and the third electrode.

  2. Three-electrode metal oxide reduction cell

    DOE Patents [OSTI]

    Dees, Dennis W. (Downers Groves, IL); Ackerman, John P. (Downers Grove, IL)

    2008-08-12T23:59:59.000Z

    A method of electrochemically reducing a metal oxide to the metal in an electrochemical cell is disclosed along with the cell. Each of the anode and cathode operate at their respective maximum reaction rates. An electrolyte and an anode at which oxygen can be evolved, and a cathode including a metal oxide to be reduced are included as is a third electrode with independent power supplies connecting the anode and the third electrode and the cathode and the third electrode.

  3. Method for making monolithic metal oxide aerogels

    DOE Patents [OSTI]

    Droege, M.W.; Coronado, P.R.; Hair, L.M.

    1995-03-07T23:59:59.000Z

    Transparent, monolithic metal oxide aerogels of varying densities are produced using a method in which a metal alkoxide solution and a catalyst solution are prepared separately and reacted. The resulting hydrolyzed-condensed colloidal solution is gelled, and the wet gel is contained within a sealed, but gas permeable, containment vessel during supercritical extraction of the solvent. The present invention is especially advantageous for making metal oxides other than silica that are prone to forming opaque, cracked aerogels. 6 figs.

  4. Method for making monolithic metal oxide aerogels

    DOE Patents [OSTI]

    Droege, Michael W. (Livermore, CA); Coronado, Paul R. (Livermore, CA); Hair, Lucy M. (Livermore, CA)

    1995-01-01T23:59:59.000Z

    Transparent, monolithic metal oxide aerogels of varying densities are produced using a method in which a metal alkoxide solution and a catalyst solution are prepared separately and reacted. The resulting hydrolyzed-condensed colloidal solution is gelled, and the wet gel is contained within a sealed, but gas permeable, containment vessel during supercritical extraction of the solvent. The present invention is especially advantageous for making metal oxides other than silica that are prone to forming opaque, cracked aerogels.

  5. Direct electrochemical reduction of metal-oxides

    DOE Patents [OSTI]

    Redey, Laszlo I. (Downers Grove, IL); Gourishankar, Karthick (Downers Grove, IL)

    2003-01-01T23:59:59.000Z

    A method of controlling the direct electrolytic reduction of a metal oxide or mixtures of metal oxides to the corresponding metal or metals. A non-consumable anode and a cathode and a salt electrolyte with a first reference electrode near the non-consumable anode and a second reference electrode near the cathode are used. Oxygen gas is produced and removed from the cell. The anode potential is compared to the first reference electrode to prevent anode dissolution and gas evolution other than oxygen, and the cathode potential is compared to the second reference electrode to prevent production of reductant metal from ions in the electrolyte.

  6. Nanocomposite of graphene and metal oxide materials | OSTI, US...

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

    Nanocomposite of graphene and metal oxide materials Re-direct Destination: Nanocomposite materials comprising a metal oxide bonded to at least one graphene material. The...

  7. Monolithic Metal Oxide based Composite Nanowire Lean NOx Emission...

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

    Monolithic Metal Oxide based Composite Nanowire Lean NOx Emission Control Catalysts Monolithic Metal Oxide based Composite Nanowire Lean NOx Emission Control Catalysts Presents...

  8. Microwave-assisted synthesis of transition metal phosphide

    DOE Patents [OSTI]

    Viswanathan, Tito

    2014-12-30T23:59:59.000Z

    A method of synthesizing transition metal phosphide. In one embodiment, the method has the steps of preparing a transition metal lignosulfonate, mixing the transition metal lignosulfonate with phosphoric acid to form a mixture, and subjecting the mixture to a microwave radiation for a duration of time effective to obtain a transition metal phosphide.

  9. Method of boronizing transition metal surfaces

    DOE Patents [OSTI]

    Koyama, Koichiro; Shimotake, Hiroshi.

    1983-08-16T23:59:59.000Z

    A method is presented for preparing a boride layer on a transition metal substrate for use in corrosive environments or as a harden surface in machine applications. This method is particularly useful in treating current collectors for use within a high temperature and corrosive electrochemical cell environment. A melt of a alkali metal boride tetrafluoride salt including such as KF to lower its melting point is prepared including a dissolved boron containing material, for instance NiB, MnB[sub 2], or CrB[sub 2]. A transition metal to be coated is immersed in the melt at a temperature of no more than 700 C and a surface boride layer of that transition metal is formed within a period of about 24 hours on the substrate surface. 4 figs.

  10. Method of boronizing transition metal surfaces

    DOE Patents [OSTI]

    Koyama, Koichiro (Hyogo, JP); Shimotake, Hiroshi (Hinsdale, IL)

    1983-01-01T23:59:59.000Z

    A method is presented for preparing a boride layer on a transition metal substrate for use in corrosive environments or as a harden surface in machine applications. This method is particularly useful in treating current collectors for use within a high temperature and corrosive electrochemical cell environment. A melt of a alkali metal boride tetrafluoride salt including such as KF to lower its melting point is prepared including a dissolved boron containing material, for instance NiB, MnB.sub.2, or CrB.sub.2. A transition metal to be coated is immersed in the melt at a temperature of no more than 700.degree. C. and a surface boride layer of that transition metal is formed within a period of about 24 hours on the substrate surface.

  11. [Transition metal mediated transformations of small molecules

    SciTech Connect (OSTI)

    Sen, A.

    1992-01-01T23:59:59.000Z

    Work on organotransition metal chemistry, homogeneous and heterogeneous catalysis is summarized. Several cationic palladium(II) complexes with bulky phosphine or pyridine ligands were discovered that are highly selective catalysts for linear dimerization of vinyl monomers and linear polymerization of p-divinylbenzene, the reactions proceeding through a carbocationic mechanism. Our studies were continued on alternating olefin-carbon monoxide copolymers. The copolymerization reaction and reactivity of copolymers were examined. New catalytic systems for alternating copolymerization of [alpha]-olefins with CO were discovered. In the case of styrene derivatives, tactic copolymers were obtained. Poly(ethylenepyrrolediyl) derivatives were synthesized from alternating ethylene-carbon monoxide copolymer and become electronic conductors when doped with iodine. A catalytic system for direct synthesis of polyureas and polyoxamides from and diamines was also discovered. Pt metal catalyzed the oxidation of ethers, esters, and amines to carboxylic acids and the oxidation of olefins to 1,2-diols. Anaerobic and aerobic decomposition of molybdenum(VI)-oxoalkyl compounds were studied for heterogeneous oxidation of alkanes and olefins on Mo(VI)-oxide surfaces. Synthesis of polymer-trapped metal, metal oxide, and metal sulfide nanoclusters (size <1--10 nm) was studied.

  12. High surface area, electrically conductive nanocarbon-supported metal oxide

    DOE Patents [OSTI]

    Worsley, Marcus A; Han, Thomas Yong-Jin; Kuntz, Joshua D; Cervanted, Octavio; Gash, Alexander E; Baumann, Theodore F; Satcher, Jr., Joe H

    2014-03-04T23:59:59.000Z

    A metal oxide-carbon composite includes a carbon aerogel with an oxide overcoat. The metal oxide-carbon composite is made by providing a carbon aerogel, immersing the carbon aerogel in a metal oxide sol under a vacuum, raising the carbon aerogel with the metal oxide sol to atmospheric pressure, curing the carbon aerogel with the metal oxide sol at room temperature, and drying the carbon aerogel with the metal oxide sol to produce the metal oxide-carbon composite. The step of providing a carbon aerogel can provide an activated carbon aerogel or provide a carbon aerogel with carbon nanotubes that make the carbon aerogel mechanically robust.

  13. Alkane oxidation with porphyrins and metal complexes thereof having haloalkyl side chains

    DOE Patents [OSTI]

    Wijesekera, T.; Lyons, J.E.; Ellis, P.E. Jr.; Bhinde, M.V.

    1998-06-23T23:59:59.000Z

    Transition metal complexes of meso-haloalkylporphyrins are disclosed, wherein the haloalkyl groups contain 2 to 8 carbon atoms have been found to be highly effective catalysts for oxidation of alkanes and for the decomposition of hydroperoxides. 7 figs.

  14. Alkane oxidation with porphyrins and metal complexes thereof having haloalkyl side chains

    DOE Patents [OSTI]

    Wijesekera, Tilak (Glen Mills, PA); Lyons, James E. (Wallingford, PA); Ellis, Jr., Paul E. (Downingtown, PA); Bhinde, Manoj V. (Boothwyn, PA)

    1998-01-01T23:59:59.000Z

    Transition metal complexes of meso-haloalkylporphyrins, wherein the haloalkyl groups contain 2 to 8 carbon atoms have been found to be highly effective catalysts for oxidation of alkanes and for the decomposition of hydroperoxides.

  15. Process for etching mixed metal oxides

    DOE Patents [OSTI]

    Ashby, C.I.H.; Ginley, D.S.

    1994-10-18T23:59:59.000Z

    An etching process is described using dicarboxylic and tricarboxylic acids as chelating etchants for mixed metal oxide films such as high temperature superconductors and ferroelectric materials. Undesirable differential etching rates between different metal oxides are avoided by selection of the proper acid or combination of acids. Feature sizes below one micron, excellent quality vertical edges, and film thicknesses in the 100 Angstrom range may be achieved by this method. 1 fig.

  16. Process for etching mixed metal oxides

    DOE Patents [OSTI]

    Ashby, Carol I. H. (Edgewood, NM); Ginley, David S. (Evergreen, CO)

    1994-01-01T23:59:59.000Z

    An etching process using dicarboxylic and tricarboxylic acids as chelating etchants for mixed metal oxide films such as high temperature superconductors and ferroelectric materials. Undesirable differential etching rates between different metal oxides are avoided by selection of the proper acid or combination of acids. Feature sizes below one micron, excellent quality vertical edges, and film thicknesses in the 100 Angstom range may be achieved by this method.

  17. Method for making monolithic metal oxide aerogels

    SciTech Connect (OSTI)

    Coronado, Paul R. (Livermore, CA)

    1999-01-01T23:59:59.000Z

    Transparent, monolithic metal oxide aerogels of varying densities are produced using a method in which a metal alkoxide solution and a catalyst solution are prepared separately and reacted. The resulting hydrolyzed-condensed colloidal solution is gelled, and the wet gel is contained within a sealed, but gas permeable, containment vessel during supercritical extraction of the solvent. The containment vessel is enclosed within an aqueous atmosphere that is above the supercritical temperature and pressure of the solvent of the metal alkoxide solution.

  18. Spin transition in a four-coordinate iron oxide

    SciTech Connect (OSTI)

    Kawakami, T. [Nihon University, Tokyo; Sutou, S. [Nihon University, Tokyo; Hirama, H. [Nihon University, Tokyo; Sekiya, Y. [Nihon University, Tokyo; Makino, T. [Nihon University, Tokyo; Tsujimoto, Y. [Kyoto University, Japan; Kitada, A. [Kyoto University, Japan; Tassel, C. [Kyoto University, Japan; Kageyama, H. [Kyoto University, Japan; Yoshimura, K. [Kyoto University, Japan; Chen, Xingqiu [ORNL; Fu, Chong Long [ORNL; Okada, T. [University of Tokyo, Tokyo, Japan; Yagi, T. [University of Tokyo, Tokyo, Japan; Hayashi, N. [Kyoto University, Japan; Nasu, S. [Osaka University; Podloucky, R. [Institut fur Physikalische Chemie der RWTH; Takano, M. [Kyoto University, Japan

    2009-01-01T23:59:59.000Z

    The spin transition, or spin crossover, is a manifestation of electronic instability induced by external constraints such as pressure1. Among known examples that exhibit spin transition, 3d ions with d6 electron configurations represent the vast majority, but the spin transition observed thus far has been almost exclusively limited to that between high-spin (S = 2) and low-spin (S = 0) states2-9. Here we report a novel high-spin to intermediate-spin (S = 1) state transition at 33 GPa induced by pressurization of an antiferromagnetic insulator SrFeO2 with a square planar coordination10. The change in spin multiplicity brings to ferromagnetism as well as metallicity, yet keeping the ordering temperature far above ambient. First-principles calculations attribute the origin of the transition to the strong inlayer hybridization between Fe dx 2 -y 2 O p , leading to a pressure-induced electronic instability toward the depopulation of Fe dx 2 -y 2 O p antibonding states. Furthermore, the ferromagnetic S = 1 state is half-metallic due to the inception of half-occupied spin-down (dxz, dyz) degenerate states upon spin transition. These results highlight the square-planar coordinated iron oxides as a new class of magnetic and electric materials and provide new avenues toward realizing multi-functional sensors and data-storage devices.

  19. PLUTONIUM METAL: OXIDATION CONSIDERATIONS AND APPROACH

    SciTech Connect (OSTI)

    Estochen, E.

    2013-03-20T23:59:59.000Z

    Plutonium is arguably the most unique of all metals when considered in the combined context of metallurgical, chemical, and nuclear behavior. Much of the research in understanding behavior and characteristics of plutonium materials has its genesis in work associated with nuclear weapons systems. However, with the advent of applications in fuel materials, the focus in plutonium science has been more towards nuclear fuel applications, as well as long term storage and disposition. The focus of discussion included herein is related to preparing plutonium materials to meet goals consistent with non-proliferation. More specifically, the emphasis is on the treatment of legacy plutonium, in primarily metallic form, and safe handling, packaging, and transport to meet non-proliferation goals of safe/secure storage. Elevated temperature oxidation of plutonium metal is the treatment of choice, due to extensive experiential data related to the method, as the oxide form of plutonium is one of only a few compounds that is relatively simple to produce, and stable over a large temperature range. Despite the simplicity of the steps required to oxidize plutonium metal, it is important to understand the behavior of plutonium to ensure that oxidation is conducted in a safe and effective manner. It is important to understand the effect of changes in environmental variables on the oxidation characteristics of plutonium. The primary purpose of this report is to present a brief summary of information related to plutonium metal attributes, behavior, methods for conversion to oxide, and the ancillary considerations related to processing and facility safety. The information provided is based on data available in the public domain and from experience in oxidation of such materials at various facilities in the United States. The report is provided as a general reference for implementation of a simple and safe plutonium metal oxidation technique.

  20. Thermodynamic Investigations of Lithium- and Manganese-Rich Transition...

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

    Thermodynamic Investigations of Lithium- and Manganese-Rich Transition Metal Oxides Thermodynamic Investigations of Lithium- and Manganese-Rich Transition Metal Oxides 2013 DOE...

  1. Tuning of the Metal-Insulator Transition via Alkali Adsorption

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

    Tuning of the Metal-Insulator Transition via Alkali Adsorption Tuning of the Metal-Insulator Transition via Alkali Adsorption Print Wednesday, 29 March 2006 00:00 Turning a...

  2. Cation dopant distributions in nanostructures of transition-metal...

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

    dopant distributions in nanostructures of transition-metal doped ZnO:Monte Carlo simulations. Cation dopant distributions in nanostructures of transition-metal doped ZnO:Monte...

  3. Reduction of metal oxides through mechanochemical processing

    DOE Patents [OSTI]

    Froes, Francis H. (Moscow, ID); Eranezhuth, Baburaj G. (Moscow, ID); Senkov, Oleg N. (Moscow, ID)

    2000-01-01T23:59:59.000Z

    The low temperature reduction of a metal oxide using mechanochemical processing techniques. The reduction reactions are induced mechanically by milling the reactants. In one embodiment of the invention, titanium oxide TiO.sub.2 is milled with CaH.sub.2 to produce TiH.sub.2. Low temperature heat treating, in the range of 400.degree. C. to 700.degree. C., can be used to remove the hydrogen in the titanium hydride.

  4. Single-layer transition metal sulfide catalysts

    DOE Patents [OSTI]

    Thoma, Steven G. (Albuquerque, NM)

    2011-05-31T23:59:59.000Z

    Transition Metal Sulfides (TMS), such as molybdenum disulfide (MoS.sub.2), are the petroleum industry's "workhorse" catalysts for upgrading heavy petroleum feedstocks and removing sulfur, nitrogen and other pollutants from fuels. We have developed an improved synthesis technique to produce SLTMS catalysts, such as molybdenum disulfide, with potentially greater activity and specificity than those currently available. Applications for this technology include heavy feed upgrading, in-situ catalysis, bio-fuel conversion and coal liquefaction.

  5. Metal sulfide initiators for metal oxide sorbent regeneration

    DOE Patents [OSTI]

    Turk, B.S.; Gupta, R.P.

    1999-06-22T23:59:59.000Z

    A process of regenerating a sulfided sorbent is provided. According to the process of the invention, a substantial portion of the energy necessary to initiate the regeneration reaction is provided by the combustion of a particulate metal sulfide additive. In using the particulate metal sulfide additive, the oxygen-containing gas used to regenerate the sulfided sorbent can be fed to the regeneration zone without heating or at a lower temperature than used in conventional processes wherein the regeneration reaction is initiated only by heating the oxygen-containing gas. The particulate metal sulfide additive is preferably an inexpensive mineral ore such as iron pyrite which does not adversely affect the regeneration or corresponding desulfurization reactions. The invention further includes a sorbent composition comprising the particulate metal sulfide additive in admixture with an active metal oxide sorbent capable of removing one or more sulfur compounds from a sulfur-containing gas stream. 1 fig.

  6. Chemistry of Sulfur Oxides on Transition Metals I: Configurations, Energetics, Orbital Analyses, and Surface Coverage Effects of SO2 on Pt(111)

    E-Print Network [OSTI]

    Lin, Xi

    on understanding how SO2 promotes the oxidation of alkanes, such as propane.3-5 To understand the reactivity, Polcik et al. did not pro- pose any detailed structural information for this flat-lying configuration

  7. Corrosion behavior of mesoporous transition metal nitrides

    SciTech Connect (OSTI)

    Yang, Minghui, E-mail: m.yang@cornell.edu [Department of Chemistry, Cornell University, Ithaca 14853-1301, NY (United States); Allen, Amy J.; Nguyen, Minh T. [Department of Chemistry, Cornell University, Ithaca 14853-1301, NY (United States); Ralston, Walter T. [College of Chemistry, University of California, Berkeley 94720-1460, CA (United States); MacLeod, Michelle J. [Department of Chemistry, Massachusetts Institute of Technology, Cambridge 02139-4307, MA (United States); DiSalvo, Francis J., E-mail: fjd3@cornell.edu [Department of Chemistry, Cornell University, Ithaca 14853-1301, NY (United States)

    2013-09-15T23:59:59.000Z

    Transition metal nitrides (TMN) have many desirable characteristics such as high hardness and good thermal stability under reducing conditions. This work reports an initial survey of the chemical stability of mesoporous TMNs (TM=Nb, V, Cr and Ti) in water at 80 °C at neutral, acidic and alkaline pH. The mesoporous TMNs had specific surface areas of 25–60 m{sup 2}/g with average pore sizes ranging from 10 to 50 nm. The high surface areas of these materials enhance the rate of corrosion per unit mass over that of a bulk material, making detection of corrosion much easier. The products were characterized by Rietveld refinement of powder X-ray diffraction (PXRD) patterns and by scanning electron microscopy (SEM). Several nitrides have corrosion rates that are, within error, not distinguishable from zero (±1 Å/day). Of the nitrides examined, CrN appears to be the most corrosion resistant under acidic conditions. None of the nitrides studied are corrosion resistant under alkaline conditions. - Graphical abstract: Corrosion behavior of mesoporous transition metal nitrides (TM=Nb, V, Cr and Ti) in acidic and alkaline solutions at 80 °C for 2 weeks. Display Omitted - highlights: • Corrosion rates of mesoporous transition metal nitrides in aqueous solution is reported. • The mesoporous TMNs had surface areas of 25–60 m{sup 2}/g. • CrN is the most corrosion resistant under the conditions studied.

  8. Metal-insulator transition in holography

    E-Print Network [OSTI]

    Aristomenis Donos; Sean A. Hartnoll

    2013-01-19T23:59:59.000Z

    We exhibit an interaction-driven metal-insulator quantum phase transition in a holographic model. Use of a helical lattice enables us to break translation invariance while preserving homogeneity. The metallic phase is characterized by a sharp Drude peak and a d.c. resistivity that increases with temperature. In the insulating phase the Drude spectral weight is transferred into a `mid-infrared' peak and to energy scales of order the chemical potential. The d.c. resistivity now decreases with temperature. In the metallic phase, operators breaking translation invariance are irrelevant at low energy scales. In the insulating phase, translation symmetry breaking effects are present at low energies. We find the near horizon extremal geometry that captures the insulating physics.

  9. Metal-supported solid oxide fuel cells

    SciTech Connect (OSTI)

    Villarreal, I.; Jacobson, C.; Leming, A.; Matus, Y.; Visco, S.; De Jonghe, L.

    2003-01-07T23:59:59.000Z

    Low cost, colloidal deposition methods have been utilized to produce novel solid oxide fuel cell structures on metal alloy support electrodes. YSZ films were deposited on iron-chrome supports on top of a thin Ni/YSZ catalytic layer, and sintered at 1350 degrees C, in a reducing atmosphere. Dense, 20??m YSZ electrolyte films were obtained on highly porous stainless steel substrates.

  10. Reactor process using metal oxide ceramic membranes

    DOE Patents [OSTI]

    Anderson, M.A.

    1994-05-03T23:59:59.000Z

    A reaction vessel for use in photoelectrochemical reactions includes as its reactive surface a metal oxide porous ceramic membrane of a catalytic metal such as titanium. The reaction vessel includes a light source and a counter electrode. A provision for applying an electrical bias between the membrane and the counter electrode permits the Fermi levels of potential reaction to be favored so that certain reactions may be favored in the vessel. The electrical biasing is also useful for the cleaning of the catalytic membrane. Also disclosed is a method regenerating a porous metal oxide ceramic membrane used in a photoelectrochemical catalytic process by periodically removing the reactants and regenerating the membrane using a variety of chemical, thermal, and electrical techniques. 2 figures.

  11. Method for producing nanostructured metal-oxides

    DOE Patents [OSTI]

    Tillotson, Thomas M.; Simpson, Randall L.; Hrubesh, Lawrence W.; Gash, Alexander

    2006-01-17T23:59:59.000Z

    A synthetic route for producing nanostructure metal-oxide-based materials using sol-gel processing. This procedure employs the use of stable and inexpensive hydrated-metal inorganic salts and environmentally friendly solvents such as water and ethanol. The synthesis involves the dissolution of the metal salt in a solvent followed by the addition of a proton scavenger, which induces gel formation in a timely manner. Both critical point (supercritical extraction) and atmospheric (low temperature evaporation) drying may be employed to produce monolithic aerogels and xerogels, respectively. Using this method synthesis of metal-oxide nanostructured materials have been carried out using inorganic salts, such as of Fe3+, Cr3+, Al3+, Ga3+, In3+, Hf4+, Sn4+, Zr4+, Nb5+, W6+, Pr3+, Er3+, Nd3+, Ce3+, U3+ and Y3+. The process is general and nanostructured metal-oxides from the following elements of the periodic table can be made: Groups 2 through 13, part of Group 14 (germanium, tin, lead), part of Group 15 (antimony, bismuth), part of Group 16 (polonium), and the lanthanides and actinides. The sol-gel processing allows for the addition of insoluble materials (e.g., metals or polymers) to the viscous sol, just before gelation, to produce a uniformly distributed nanocomposites upon gelation. As an example, energetic nanocomposites of FexOy gel with distributed Al metal are readily made. The compositions are stable, safe, and can be readily ignited to thermitic reaction.

  12. Thermal barrier and overlay coating systems comprising composite metal/metal oxide bond coating layers

    DOE Patents [OSTI]

    Goedjen, John G. (Oviedo, FL); Sabol, Stephen M. (Orlando, FL); Sloan, Kelly M. (Longwood, FL); Vance, Steven J. (Orlando, FL)

    2001-01-01T23:59:59.000Z

    The present invention generally describes multilayer coating systems comprising a composite metal/metal oxide bond coat layer. The coating systems may be used in gas turbines.

  13. Metal oxide and metal fluoride nanostructures and methods of making same

    DOE Patents [OSTI]

    Wong, Stanislaus S. (Stony Brook, NY); Mao, Yuanbing (Los Angeles, CA)

    2009-08-18T23:59:59.000Z

    The present invention includes pure single-crystalline metal oxide and metal fluoride nanostructures, and methods of making same. These nanostructures include nanorods and nanoarrays.

  14. Hydrous metal oxide catalysts for oxidation of hydrocarbons

    SciTech Connect (OSTI)

    Miller, J.E.; Dosch, R.G.; McLaughlin, L.I. [Sandia National Labs., Albuquerque, NM (United States). Process Research Dept.

    1993-07-01T23:59:59.000Z

    This report describes work performed at Sandia under a CRADA with Shell Development of Houston, Texas aimed at developing hydrous metal oxide (HMO) catalysts for oxidation of hydrocarbons. Autoxidation as well as selective oxidation of 1-octene was studied in the presence of HMO catalysts based on known oxidation catalysts. The desired reactions were the conversion of olefin to epoxides, alcohols, and ketones, HMOs seem to inhibit autoxidation reactions, perhaps by reacting with peroxides or radicals. Attempts to use HMOs and metal loaded HMOs as epoxidation catalysts were unsuccessful, although their utility for this reaction was not entirely ruled out. Likewise, alcohol formation from olefins in the presence of HMO catalysts was not achieved. However, this work led to the discovery that acidified HMOs can lead to carbocation reactions of hydrocarbons such as cracking. An HMO catalyst containing Rh and Cu that promotes the reaction of {alpha}-olefins with oxygen to form methyl ketones was identified. Although the activity of the catalyst is relatively low and isomerization reactions of the olefin simultaneously occur, results indicate that these problems may be addressed by eliminating mass transfer limitations. Other suggestions for improving the catalyst are also made. 57 refs.

  15. Versatile Applications of Nanostructured Metal Oxides

    E-Print Network [OSTI]

    Li, Li

    2014-05-29T23:59:59.000Z

    and technological fields, in- cluding catalysis, sensors, energy devices (batteries, solar cells and fuel cells), optics and biomedicine.[11] Nanoporous metal oxides have therefore gained tremendous in- terest during the past decades. They show greatly improved... 1998, 396, 152. [4] S. Guldin, S. Hüttner, M. Kolle, M. E. Welland, P. Müller-Buschbaum, R. H. Friend, U. Steiner, N. Tétreault, Dye-sensitized solar cell based on a three- dimensional photonic crystal, Nano Lett. 2010, 10, 2303. [5] R. L. Puurunen...

  16. Tuning of the Metal-Insulator Transition via Alkali Adsorption

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

    Tuning of the Metal-Insulator Transition via Alkali Adsorption Print Turning a material from an insulator to a metal, or vice versa, by light irradiation, exposure to electric or...

  17. Method for producing metal oxide aerogels

    SciTech Connect (OSTI)

    Tillotson, Thomas M. (Tracy, CA); Poco, John F. (Livermore, CA); Hrubesh, Lawrence W. (Pleasanton, CA); Thomas, Ian M. (Livermore, CA)

    1995-01-01T23:59:59.000Z

    A two-step hydrolysis-condensation method was developed to form metal oxide aerogels of any density, including densities of less than 0.003g/cm.sup.3 and greater than 0.27g/cm.sup.3. High purity metal alkoxide is reacted with water, alcohol solvent, and an additive to form a partially condensed metal intermediate. All solvent and reaction-generated alcohol is removed, and the intermediate is diluted with a nonalcoholic solvent. The intermediate can be stored for future use to make aerogels of any density. The aerogels are formed by reacting the intermediate with water, nonalcoholic solvent, and a catalyst, and extracting the nonalcoholic solvent directly. The resulting monolithic aerogels are hydrophobic and stable under atmospheric conditions, and exhibit good optical transparency, high clarity, and homogeneity. The aerogels have high thermal insulation capacity, high porosity, mechanical strength and stability, and require shorter gelation times than aerogels formed by conventional methods.

  18. Method for producing metal oxide aerogels

    SciTech Connect (OSTI)

    Tillotson, T.M.; Poco, J.F.; Hrubesh, L.W.; Thomas, I.M.

    1995-04-25T23:59:59.000Z

    A two-step hydrolysis-condensation method was developed to form metal oxide aerogels of any density, including densities of less than 0.003g/cm{sup 3} and greater than 0.27g/cm{sup 3}. High purity metal alkoxide is reacted with water, alcohol solvent, and an additive to form a partially condensed metal intermediate. All solvent and reaction-generated alcohol is removed, and the intermediate is diluted with a nonalcoholic solvent. The intermediate can be stored for future use to make aerogels of any density. The aerogels are formed by reacting the intermediate with water, nonalcoholic solvent, and a catalyst, and extracting the nonalcoholic solvent directly. The resulting monolithic aerogels are hydrophobic and stable under atmospheric conditions, and exhibit good optical transparency, high clarity, and homogeneity. The aerogels have high thermal insulation capacity, high porosity, mechanical strength and stability, and require shorter gelation times than aerogels formed by conventional methods. 8 figs.

  19. Femtosecond NEXAFS of Photoinduced Insulator-Metal Transition...

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

    delocalization of the charge carriers in the spatially extended conduction band cause an ultrafast transition to the metallic state as the valence and conductions bands once...

  20. Electronic and structural dynamics in transition metal complexes...

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

    Electronic and structural dynamics in transition metal complexes - recent results from synchrotron and XFEL experiments Wednesday, March 4, 2015 - 3:00pm SLAC, Redtail Hawk...

  1. Polymer-assisted aqueous deposition of metal oxide films

    DOE Patents [OSTI]

    Li, DeQuan (Los Alamos, NM); Jia, Quanxi (Los Alamos, NM)

    2003-07-08T23:59:59.000Z

    An organic solvent-free process for deposition of metal oxide thin films is presented. The process includes aqueous solutions of necessary metal precursors and an aqueous solution of a water-soluble polymer. After a coating operation, the resultant coating is fired at high temperatures to yield optical quality metal oxide thin films.

  2. Slag Metal Reactions in Binary CaF2-Metal Oxide Welding Fluxes

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ) Slag Metal Reactions in Binary CaF2-Metal Oxide Welding Fluxes Some otherwise chemically stable fluxes may decompose into suboxides in the presence of welding arcs, thereby providing higher levels of 0 2 in weld metal than those oxides which do not form suboxides ABSTRACT. The stability of metal

  3. Electronic Transitions in Perovskite Oxide Heterostructures

    E-Print Network [OSTI]

    Wong, Franklin

    2011-01-01T23:59:59.000Z

    alkaline-earth metals, rare-earth metals, Bi, and Pb. Withalkaline-earth and rare-earth metals occupy the A sites and3 (R = trivalent rare-earth metal, A = divalent alkaline-

  4. Near room temperature lithographically processed metal-oxide transistors

    E-Print Network [OSTI]

    Tang, Hui, M. Eng. Massachusetts Institute of Technology

    2008-01-01T23:59:59.000Z

    A fully lithographic process at near-room-temperature was developed for the purpose of fabricating transistors based on metal-oxide channel materials. The combination of indium tin oxide (ITO) as the source/drain electrodes, ...

  5. Surface Oxidation and Dissolution of Metal Nanocatalysts in Acid Medium 

    E-Print Network [OSTI]

    Callejas-Tovar, Juan

    2012-10-19T23:59:59.000Z

    the main features of the oxidation phenomena observed experimentally, it is concluded that the dissolution mechanism of metal atoms involves: 1) Surface segregation of alloy atoms, 2) oxygen absorption into the subsurface of the catalyst, and 3) metal...

  6. Metal Oxide Semiconductor Nanoparticles Open the Door to New...

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

    Innovations Technology available for licensing: novel nanometer-sized metal oxide semiconductors that allow targeting, initiating and control of in vitro and in vivo chemical...

  7. The strong reactions of Lewis-base noble-metals with vanadium and other acidic transition metals

    SciTech Connect (OSTI)

    Ebbinghaus, B.B.

    1991-05-01T23:59:59.000Z

    The noble metals often thought of as unreactive solids,react strongly with nearly 40% of the elements in the periodictable: group IIIB-VB transition metals, lanthanides, theactinides, and group IIIA-IVA non-transition metals. These strong reactions arise from increased bonding/electron transfer fromnonbonding electrons d electron pairs on the noble metal tovacant orbitals on V, etc. This effect is a generalized Lewis acid-base interaction. The partial Gibbs energy of V in the noblemetals has been measured as a function of concentration at a temperature near 1000C. Thermodynamics of the intermetallics are determined by ternary oxide equilibria, ternary carbide equilibria, and the high-temperature galvanic cell technique. These experimental methods use equilibrated solid composite mixtures in which grains of V oxides or of V carbides are interspersed with grains of V-NM(noble-metal) alloys. In equilibrium the activity of V in the oxide or the carbide equals the activity in the alloy. Consequently, the thermodynamics available in the literature for the V oxides and V carbides are reviewed. Test runs on the galvanic cell were attempted. The V oxide electrode reacts with CaF[sub 2], ThO[sub 2], YDT(0.85ThO[sub 2]-0.15YO[sub 1.5]), and LDT(0.85ThO[sub 2]- 0.15LaO[sub 1.5]) to interfere with the measured data observed toward the beginning of a galvanic cell experiment are the most accurate. The interaction of vanadium at infinite dilution in the noble-metals was determined.

  8. The strong reactions of Lewis-base noble-metals with vanadium and other acidic transition metals

    SciTech Connect (OSTI)

    Ebbinghaus, B.B.

    1991-05-01T23:59:59.000Z

    The noble metals often thought of as unreactive solids,react strongly with nearly 40% of the elements in the periodictable: group IIIB-VB transition metals, lanthanides, theactinides, and group IIIA-IVA non-transition metals. These strong reactions arise from increased bonding/electron transfer fromnonbonding electrons d electron pairs on the noble metal tovacant orbitals on V, etc. This effect is a generalized Lewis acid-base interaction. The partial Gibbs energy of V in the noblemetals has been measured as a function of concentration at a temperature near 1000C. Thermodynamics of the intermetallics are determined by ternary oxide equilibria, ternary carbide equilibria, and the high-temperature galvanic cell technique. These experimental methods use equilibrated solid composite mixtures in which grains of V oxides or of V carbides are interspersed with grains of V-NM(noble-metal) alloys. In equilibrium the activity of V in the oxide or the carbide equals the activity in the alloy. Consequently, the thermodynamics available in the literature for the V oxides and V carbides are reviewed. Test runs on the galvanic cell were attempted. The V oxide electrode reacts with CaF{sub 2}, ThO{sub 2}, YDT(0.85ThO{sub 2}-0.15YO{sub 1.5}), and LDT(0.85ThO{sub 2}- 0.15LaO{sub 1.5}) to interfere with the measured data observed toward the beginning of a galvanic cell experiment are the most accurate. The interaction of vanadium at infinite dilution in the noble-metals was determined.

  9. Method of producing solution-derived metal oxide thin films

    DOE Patents [OSTI]

    Boyle, Timothy J. (Albuquerque, NM); Ingersoll, David (Albuquerque, NM)

    2000-01-01T23:59:59.000Z

    A method of preparing metal oxide thin films by a solution method. A .beta.-metal .beta.-diketonate or carboxylate compound, where the metal is selected from groups 8, 9, 10, 11, and 12 of the Periodic Table, is solubilized in a strong Lewis base to form a homogeneous solution. This precursor solution forms within minutes and can be deposited on a substrate in a single layer or a multiple layers to form a metal oxide thin film. The substrate with the deposited thin film is heated to change the film from an amorphous phase to a ceramic metal oxide and cooled.

  10. METAL-NON METAL TRANSITIONS /N RARE EARTH COMPOUNDS. EXPERIMENT AND THEORK /.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    METAL-NON METAL TRANSITIONS /N RARE EARTH COMPOUNDS. EXPERIMENT AND THEORK /. VALENCE INSTABILITIES, superconductivity, electron-phonon and band theory, to name a few. 2. Properties of normal rare earth metals. - Before discussing rare earth valence instabilities, three relevant general features of rare earth metals

  11. Transition metal-free olefin polymerization catalyst

    DOE Patents [OSTI]

    Sen, Ayusman (State College, PA); Wojcinski, II, Louis M. (State College, PA); Liu, Shengsheng (State College, PA)

    2001-01-01T23:59:59.000Z

    Ethylene and/or propylene are polymerized to form high molecular weight, linear polymers by contacting ethylene and/or propylene monomer, in the presence of an inert reaction medium, with a catalyst system which consists essentially of (1) an aluminum alkyl component, such as trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-octylaluminum and diethylaluminum hydride and (2) a Lewis acid or Lewis acid derivative component, such as B (C.sub.6 F.sub.5).sub.3, [(CH.sub.3).sub.2 N (H) (C.sub.6 H.sub.5)].sup.+ [B (C.sub.6 F.sub.5)4].sup.-, [(C.sub.2 H.sub.5).sub.3 NH].sup.+ [B C.sub.6 F.sub.5).sub.4 ],.sup.-, [C(C.sub.6 F.sub.5).sub.3 ].sup.+ [B(C.sub.6 F.sub.5).sub.4 ].sup.-, (C.sub.2 H.sub.5).sub.2 Al(OCH.sub.3), (C.sub.2 H.sub.5).sub.2 Al(2,6-di-t-butyl-4-methylphenoxide), (C.sub.2 H.sub.5)Al(2,6 -di-t-butylphenoxide).sub.2, (C.sub.2 H.sub.5).sub.2 Al(2,6-di-t-butylphonoxide) , 2,6 -di-t-butylphenol.multidot.methylaluminoxane or an alkylaluminoxane, and which may be completely free any transition metal component(s).

  12. Using a Semiconductor-to-Metal Transition to Control Optical Transmission through Subwavelength Hole Arrays

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

    Donev, E. U.; Suh, J. Y.; Lopez, R.; Feldman, L. C.; Haglund, R. F.

    2008-01-01T23:59:59.000Z

    We describe a simple configuration in which the extraordinary optical transmission effect through subwavelength hole arrays in noble-metal films can be switched by the semiconductor-to-metal transition in an underlying thin film of vanadium dioxide. In these experiments, the transition is brought about by thermal heating of the bilayer film. The surprising reverse hysteretic behavior of the transmission through the subwavelength holes in the vanadium oxide suggest that this modulation is accomplished by a dielectric-matching condition rather than plasmon coupling through the bilayer film. The results of this switching, including the wavelength dependence, are qualitatively reproduced by a transfer matrix model.more »The prospects for effecting a similar modulation on a much faster time scale by using ultrafast laser pulses to trigger the semiconductor-to-metal transition are also discussed.« less

  13. Solder for oxide layer-building metals and alloys

    DOE Patents [OSTI]

    Kronberg, James W. (108 Independent Blvd., Aiken, SC 29801)

    1992-01-01T23:59:59.000Z

    A low temperature solder and method for soldering an oxide layer-building metal such as aluminum, titanium, tantalum or stainless steel. The comosition comprises tin and zinc; germanium as a wetting agent; preferably small amounts of copper and antimony; and a grit, such as silicon carbide. The grit abrades any oxide layer formed on the surface of the metal as the germanium penetrates beneath and loosens the oxide layer to provide good metal-to-metal contact. The germanium comprises less than aproximatley 10% by weight of the solder composition so that it provides sufficient wetting action but does not result in a melting temperature above approximately 300.degree. C. The method comprises the steps rubbing the solder against the metal surface so the grit in the solder abrades the surface while heating the surface until the solder begins to melt and the germanium penetrates the oxide layer, then brushing aside any oxide layer loosened by the solder.

  14. Solder for oxide layer-building metals and alloys

    DOE Patents [OSTI]

    Kronberg, J.W.

    1992-09-15T23:59:59.000Z

    A low temperature solder and method for soldering an oxide layer-building metal such as aluminum, titanium, tantalum or stainless steel is disclosed. The composition comprises tin and zinc; germanium as a wetting agent; preferably small amounts of copper and antimony; and a grit, such as silicon carbide. The grit abrades any oxide layer formed on the surface of the metal as the germanium penetrates beneath and loosens the oxide layer to provide good metal-to-metal contact. The germanium comprises less than approximately 10% by weight of the solder composition so that it provides sufficient wetting action but does not result in a melting temperature above approximately 300 C. The method comprises the steps rubbing the solder against the metal surface so the grit in the solder abrades the surface while heating the surface until the solder begins to melt and the germanium penetrates the oxide layer, then brushing aside any oxide layer loosened by the solder.

  15. Oxidized film structure and method of making epitaxial metal oxide structure

    DOE Patents [OSTI]

    Gan, Shupan [Richland, WA; Liang, Yong [Richland, WA

    2003-02-25T23:59:59.000Z

    A stable oxidized structure and an improved method of making such a structure, including an improved method of making an interfacial template for growing a crystalline metal oxide structure, are disclosed. The improved method comprises the steps of providing a substrate with a clean surface and depositing a metal on the surface at a high temperature under a vacuum to form a metal-substrate compound layer on the surface with a thickness of less than one monolayer. The compound layer is then oxidized by exposing the compound layer to essentially oxygen at a low partial pressure and low temperature. The method may further comprise the step of annealing the surface while under a vacuum to further stabilize the oxidized film structure. A crystalline metal oxide structure may be subsequently epitaxially grown by using the oxidized film structure as an interfacial template and depositing on the interfacial template at least one layer of a crystalline metal oxide.

  16. Electronic structures of transition metal to hydrogen bonds: oxidative addition of dihydrogen to a square planar rhodium complex and quantum mechanical prediction of the geometry of a metal hydride

    E-Print Network [OSTI]

    Halpin, Carolyn F.

    1986-01-01T23:59:59.000Z

    and applications is dihydrogen or molecular hydrogen. Both the Heber process, in which nitrogen is converted to ammonia on an iron catalyst, and the Fischer-Tropsch synthesis, in which carbon monoxide is converted to hydrocarbons over iron and cobalt catalysts... systems containing hydride ligands. This work presents a computational method for examining the energetics and structures of two systems. The reaction RhC1(CO)(PHs)z + Hz ~ (H)zRhC1(CO)(PHs)z was examined to a~plain why the oxidation of RhCI(CO...

  17. Optical properties of two-dimensional transition metal dichalcogenides

    E-Print Network [OSTI]

    Lin, Yuxuan, S.M. Massachusetts Institute of Technology

    2014-01-01T23:59:59.000Z

    The re-discovery of the atomically thin transition metal dichalcogenides (TMDs), which are mostly semiconductors with a wide range of band gaps, has diversified the family of two-dimensional materials and boosted the ...

  18. Photochemical reductive elimination of halogen from transition metal complexes

    E-Print Network [OSTI]

    Cook, Timothy R. (Timothy Raymond), 1982-

    2010-01-01T23:59:59.000Z

    This thesis is focused on the synthesis and study of transition metal complexes that undergo halogen elimination when irradiated with UV and visible light. This chemistry is relevant for solar energy storage schemes in ...

  19. Reduction of spalling in mixed metal oxide desulfurization sorbents by addition of a large promoter metal oxide

    DOE Patents [OSTI]

    Poston, J.A.

    1997-12-02T23:59:59.000Z

    Mixed metal oxide pellets for removing hydrogen sulfide from fuel gas mixes derived from coal are stabilized for operation over repeated cycles of desulfurization and regeneration reactions by addition of a large promoter metal oxide such as lanthanum trioxide. The pellets, which may be principally made up of a mixed metal oxide such as zinc titanate, exhibit physical stability and lack of spalling or decrepitation over repeated cycles without loss of reactivity. The lanthanum oxide is mixed with pellet-forming components in an amount of 1 to 10 weight percent.

  20. Reduction of spalling in mixed metal oxide desulfurization sorbents by addition of a large promoter metal oxide

    DOE Patents [OSTI]

    Poston, James A. (Star City, WV)

    1997-01-01T23:59:59.000Z

    Mixed metal oxide pellets for removing hydrogen sulfide from fuel gas mixes derived from coal are stabilized for operation over repeated cycles of desulfurization and regeneration reactions by addition of a large promoter metal oxide such as lanthanum trioxide. The pellets, which may be principally made up of a mixed metal oxide such as zinc titanate, exhibit physical stability and lack of spalling or decrepitation over repeated cycles without loss of reactivity. The lanthanum oxide is mixed with pellet-forming components in an amount of 1 to 10 weight percent.

  1. Formation of metal oxides by cathodic arc deposition

    SciTech Connect (OSTI)

    Anders, S.; Anders, A.; Rubin, M.; Wang, Z.; Raoux, S.; Kong, F.; Brown, I.G.

    1995-03-01T23:59:59.000Z

    Metal oxide thin films are of interest for a number of applications. Cathodic arc deposition, an established, industrially applied technique for formation of nitrides (e.g. TiN), can also be used for metal oxide thin film formation. A cathodic arc plasma source with desired cathode material is operated in an oxygen atmosphere, and metal oxides of various stoichiometric composition can be formed on different substrates. We report here on a series of experiments on metal oxide formation by cathodic arc deposition for different applications. Black copper oxide has been deposited on ALS components to increase the radiative heat transfer between the parts. Various metal oxides such as tungsten oxide, niobium oxide, nickel oxide and vanadium oxide have been deposited on ITO glass to form electrochromic films for window applications. Tantalum oxide films are of interest for replacing polymer electrolytes. Optical waveguide structures can be formed by refractive index variation using oxide multilayers. We have synthesized multilayers of Al{sub 2}O{sub 3}/Y{sub 2}O{sub 3}/AI{sub 2}O{sub 3}/Si as possible basic structures for passive optoelectronic integrated circuits, and Al{sub 2-x}Er{sub x}O{sub 3} thin films with a variable Er concentration which is a potential component layer for the production of active optoelectronic integrated devices such as amplifiers or lasers at a wavelength of 1.53 {mu}m. Aluminum and chromium oxide films have been deposited on a number of substrates to impart improved corrosion resistance at high temperature. Titanium sub-oxides which are electrically conductive and corrosion resistant and stable in a number of aggressive environments have been deposited on various substrates. These sub-oxides are of great interest for use in electrochemical cells.

  2. NREL Demonstrates Efficient Solar Water Splitting by Metal Oxide Photoabsorber (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2014-01-01T23:59:59.000Z

    New development demonstrates that inexpensive and robust metal oxide photoabsorbers hold great promise as photoanodes for water oxidation.

  3. Method for converting uranium oxides to uranium metal

    DOE Patents [OSTI]

    Duerksen, Walter K. (Norris, TN)

    1988-01-01T23:59:59.000Z

    A process is described for converting scrap and waste uranium oxide to uranium metal. The uranium oxide is sequentially reduced with a suitable reducing agent to a mixture of uranium metal and oxide products. The uranium metal is then converted to uranium hydride and the uranium hydride-containing mixture is then cooled to a temperature less than -100.degree. C. in an inert liquid which renders the uranium hydride ferromagnetic. The uranium hydride is then magnetically separated from the cooled mixture. The separated uranium hydride is readily converted to uranium metal by heating in an inert atmosphere. This process is environmentally acceptable and eliminates the use of hydrogen fluoride as well as the explosive conditions encountered in the previously employed bomb-reduction processes utilized for converting uranium oxides to uranium metal.

  4. Second-harmonic generation in transition-metal-organic compounds

    SciTech Connect (OSTI)

    Frazier, C.C.; Harvey, M.A.; Cockerham, M.P.; Hand, H.M.; Chauchard, E.A.; Lee, C.H.

    1986-10-23T23:59:59.000Z

    The second-harmonic generation efficiencies of over 60 transition-metal-organic compounds in powder form were measured, using 1.06 ..mu..m light from a Nd:YAG laser. Most of the studied compounds were either group VI metal carbonyl arene, pyridyl, or chiral phosphine complexes. Four the complexes doubled the laser fundamental as well as or better than ammonium dihydrogen phosphate (ADP). The study shows that the same molecular features (e.g., conjugation and low-lying spectroscopic charge transfer) that contribute to second-order optical nonlinearity in organic compounds also enhance second-order effects in transition-metal-organic compounds.

  5. Catalysis using hydrous metal oxide ion exchangers

    DOE Patents [OSTI]

    Dosch, R.G.; Stephens, H.P.; Stohl, F.V.

    1983-07-21T23:59:59.000Z

    In a process which is catalyzed by a catalyst comprising an active metal on a carrier, said metal being active as a catalyst for the process, an improvement is provided wherein the catalyst is a hydrous, alkali metal or alkaline earth metal titanate, zirconate, niobate or tantalate wherein alkali or alkaline earth metal cations have been exchanged with a catalytically effective amount of cations of said metal.

  6. Molten salt extraction process for the recovery of valued transition metals from land-based and deep-sea minerals

    DOE Patents [OSTI]

    Maroni, Victor A. (Naperville, IL); von Winbush, Samuel (Huntington, NY)

    1988-01-01T23:59:59.000Z

    A process for extracting transition metals and particularly cobalt and manganese together with iron, copper and nickel from low grade ores (including ocean-floor nodules) by converting the metal oxides or other compositions to chlorides in a molten salt, and subsequently using a combination of selective distillation at temperatures below about 500.degree. C., electrolysis at a voltage not more negative than about -1.5 volt versus Ag/AgCl, and precipitation to separate the desired manganese and cobalt salts from other metals and provide cobalt and manganese in metallic forms or compositions from which these metals may be more easily recovered.

  7. Molten salt extraction process for the recovery of valued transition metals from land-based and deep-sea minerals

    DOE Patents [OSTI]

    Maroni, V.A.; von Winbush, S.

    1987-05-01T23:59:59.000Z

    A process for extracting transition metals and particularly cobalt and manganese together with iron, copper and nickel from low grade ores (including ocean-floor nodules) by converting the metal oxides or other compositions to chlorides in a molten salt, and subsequently using a combination of selective distillation at temperatures below about 500/degree/C, electrolysis at a voltage not more negative that about /minus/1.5 volt versus Ag/AgCl, and precipitation to separate the desired manganese and cobalt salts from other metals and provide cobalt and manganese in metallic forms or compositions from which these metals may be more easily recovered.

  8. Aerosol chemical vapor deposition of metal oxide films

    DOE Patents [OSTI]

    Ott, Kevin C. (4745 Trinity Dr., Los Alamos, NM 87544); Kodas, Toivo T. (5200 Noreen Dr. NE., Albuquerque, NM 87111)

    1994-01-01T23:59:59.000Z

    A process of preparing a film of a multicomponent metal oxide including: forming an aerosol from a solution comprised of a suitable solvent and at least two precursor compounds capable of volatilizing at temperatures lower than the decomposition temperature of said precursor compounds; passing said aerosol in combination with a suitable oxygen-containing carrier gas into a heated zone, said heated zone having a temperature sufficient to evaporate the solvent and volatilize said precursor compounds; and passing said volatilized precursor compounds against the surface of a substrate, said substrate having a sufficient temperature to decompose said volatilized precursor compounds whereby metal atoms contained within said volatilized precursor compounds are deposited as a metal oxide film upon the substrate is disclosed. In addition, a coated article comprising a multicomponent metal oxide film conforming to the surface of a substrate selected from the group consisting of silicon, magnesium oxide, yttrium-stabilized zirconium oxide, sapphire, or lanthanum gallate, said multicomponent metal oxide film characterized as having a substantially uniform thickness upon said FIELD OF THE INVENTION The present invention relates to the field of film coating deposition techniques, and more particularly to the deposition of multicomponent metal oxide films by aerosol chemical vapor deposition. This invention is the result of a contract with the Department of Energy (Contract No. W-7405-ENG-36).

  9. [Transition metal mediated transformations of small molecules]. Progress report

    SciTech Connect (OSTI)

    Sen, A.

    1992-10-01T23:59:59.000Z

    Work on organotransition metal chemistry, homogeneous and heterogeneous catalysis is summarized. Several cationic palladium(II) complexes with bulky phosphine or pyridine ligands were discovered that are highly selective catalysts for linear dimerization of vinyl monomers and linear polymerization of p-divinylbenzene, the reactions proceeding through a carbocationic mechanism. Our studies were continued on alternating olefin-carbon monoxide copolymers. The copolymerization reaction and reactivity of copolymers were examined. New catalytic systems for alternating copolymerization of {alpha}-olefins with CO were discovered. In the case of styrene derivatives, tactic copolymers were obtained. Poly(ethylenepyrrolediyl) derivatives were synthesized from alternating ethylene-carbon monoxide copolymer and become electronic conductors when doped with iodine. A catalytic system for direct synthesis of polyureas and polyoxamides from and diamines was also discovered. Pt metal catalyzed the oxidation of ethers, esters, and amines to carboxylic acids and the oxidation of olefins to 1,2-diols. Anaerobic and aerobic decomposition of molybdenum(VI)-oxoalkyl compounds were studied for heterogeneous oxidation of alkanes and olefins on Mo(VI)-oxide surfaces. Synthesis of polymer-trapped metal, metal oxide, and metal sulfide nanoclusters (size <1--10 nm) was studied.

  10. Method of physical vapor deposition of metal oxides on semiconductors

    DOE Patents [OSTI]

    Norton, David P. (Knoxville, TN)

    2001-01-01T23:59:59.000Z

    A process for growing a metal oxide thin film upon a semiconductor surface with a physical vapor deposition technique in a high-vacuum environment and a structure formed with the process involves the steps of heating the semiconductor surface and introducing hydrogen gas into the high-vacuum environment to develop conditions at the semiconductor surface which are favorable for growing the desired metal oxide upon the semiconductor surface yet is unfavorable for the formation of any native oxides upon the semiconductor. More specifically, the temperature of the semiconductor surface and the ratio of hydrogen partial pressure to water pressure within the vacuum environment are high enough to render the formation of native oxides on the semiconductor surface thermodynamically unstable yet are not so high that the formation of the desired metal oxide on the semiconductor surface is thermodynamically unstable. Having established these conditions, constituent atoms of the metal oxide to be deposited upon the semiconductor surface are directed toward the surface of the semiconductor by a physical vapor deposition technique so that the atoms come to rest upon the semiconductor surface as a thin film of metal oxide with no native oxide at the semiconductor surface/thin film interface. An example of a structure formed by this method includes an epitaxial thin film of (001)-oriented CeO.sub.2 overlying a substrate of (001) Ge.

  11. Flexible metallic seal for transition duct in turbine system

    DOE Patents [OSTI]

    Flanagan, James Scott; LeBegue, Jeffrey Scott; McMahan, Kevin Weston; Dillard, Daniel Jackson; Pentecost, Ronnie Ray

    2014-04-22T23:59:59.000Z

    A turbine system is disclosed. In one embodiment, the turbine system includes a transition duct. The transition duct includes an inlet, an outlet, and a passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The transition duct further includes an interface member for interfacing with a turbine section. The turbine system further includes a flexible metallic seal contacting the interface member to provide a seal between the interface member and the turbine section.

  12. area metal oxide: Topics by E-print Network

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

    Science Websites Summary: have generated considerable interest for applications such as thin film displays with improved color of a metal oxide-based QD-LED structure10 injection...

  13. Surface effects and phase stability in metal oxides nanoparticles under visible irradiation

    SciTech Connect (OSTI)

    Ricci, Pier Carlo, E-mail: carlo.ricci@dsf.unica.it; Carbonaro, C. M., E-mail: carlo.ricci@dsf.unica.it; Corpino, R., E-mail: carlo.ricci@dsf.unica.it; Chiriu, D., E-mail: carlo.ricci@dsf.unica.it; Stagi, L., E-mail: carlo.ricci@dsf.unica.it [Dipartimento di Fisica, Universitá degli Studi di Cagliari, S.P. Monserrato-Sestu Km 0,700, 09042 Monserrato (Canada) (Italy)

    2014-10-21T23:59:59.000Z

    The light induced phase transformation between stable phases of metal oxides nanoparticles is analyzed. The surrounding atmosphere as well as the defect density at the surface play a fundamental role. It has been found that in oxygen poor chamber atmosphere the phase transformation is favored, while the phase transition cannot be achieved if the defects at the surface are properly passivated. The phase transition is activated by intragap irradiation, able to activate the F- center at the surface connected to oxygen vacancies, and promoting the activation of the surface and the nucleation of neighboring crystallites. The phase transition was studied in Titanium oxide (TiO{sub 2}) and in Iron oxide (Fe{sub 2}O{sub 3}): Maghemite is subjected to a phase transformation to ??Fe{sub 2}O{sub 3} (hematite), Anatase nanoparticles converts to Rutile. The general mechanism of the phase transition and, more in general, the possibility to optically control the surface activity of metal oxides is discussed.

  14. Noble metal catalysts for oxidation of mercury in flue gas

    SciTech Connect (OSTI)

    Presto, A.A.; Granite, E.J.

    2008-04-01T23:59:59.000Z

    The use of precious metals and platinum group metals as catalysts for oxidation of mercury in flue gas is an active area of study. To date, field studies have recently focused on gold and palladium catalysts installed at pilot-scale. In this work, we introduce bench-scale results for gold, platinum, and palladium catalysts tested in realistic simulated flue gas. Initial results reveal intriguing characteristics of catalytic mercury oxidation and provide insight for future research.

  15. Plutonium metal and oxide container weld development and qualification

    SciTech Connect (OSTI)

    Fernandez, R.; Horrell, D.R.; Hoth, C.W.; Pierce, S.W.; Rink, N.A.; Rivera, Y.M.; Sandoval, V.D.

    1996-01-01T23:59:59.000Z

    Welds were qualified for a container system to be used for long-term storage of plutonium metal and oxide. Inner and outer containers are formed of standard tubing with stamped end pieces gas-tungsten-arc (GTA) welded onto both ends. The weld qualification identified GTA parameters to produce a robust weld that meets the requirements of the Department of Energy standard DOE-STD-3013-94, ``Criteria for the Safe Storage of Plutonium Metals and Oxides.``

  16. Displacement method and apparatus for reducing passivated metal powders and metal oxides

    DOE Patents [OSTI]

    Morrell; Jonathan S. (Knoxville, TN), Ripley; Edward B. (Knoxville, TN)

    2009-05-05T23:59:59.000Z

    A method of reducing target metal oxides and passivated metals to their metallic state. A reduction reaction is used, often combined with a flux agent to enhance separation of the reaction products. Thermal energy in the form of conventional furnace, infrared, or microwave heating may be applied in combination with the reduction reaction.

  17. Nanodisperse transition metal electrodes (NTME) for electrochemical cells

    DOE Patents [OSTI]

    Striebel, Kathryn A. (Oakland, CA); Wen, Shi-Jie (Sunnyvale, CA)

    2000-01-01T23:59:59.000Z

    Disclosed are transition metal electrodes for electrochemical cells using gel-state and solid-state polymers. The electrodes are suitable for use in primary and secondary cells. The electrodes (either negative electrode or positive electrode) are characterized by uniform dispersion of the transition metal at the nanoscale in the polymer. The transition metal moiety is structurally amorphous, so no capacity fade should occur due to lattice expansion/contraction mechanisms. The small grain size, amorphous structure and homogeneous distribution provide improved charge/discharge cycling performance, and a higher initial discharge rate capability. The cells can be cycled at high current densities, limited only by the electrolyte conductivity. A method of making the electrodes (positive and negative), and their usage in electrochemical cells are disclosed.

  18. Enhanced Half-Metallicity in Edge-Oxidized Zigzag Graphene

    E-Print Network [OSTI]

    Hod, Oded

    Enhanced Half-Metallicity in Edge-Oxidized Zigzag Graphene Nanoribbons Oded Hod,* Vero´nica Barone theoretical study of the electronic properties and relative stabilities of edge-oxidized zigzag graphene with nanometer scale dimen- sions. Recently, a new type of graphene-based material was experimentally realized.12

  19. Tribochemical properties of metastable states of transition metals

    E-Print Network [OSTI]

    Kar, Prasenjit

    2009-05-15T23:59:59.000Z

    found tantalum oxides with their stoichiometric ratio and crystal structure...................................................................................................... 57 4.8 The effects on metal-polishing pad... polishing (TCP) in which the working surface is rubbed on a hard surface like ceramics and stainless steel as proposed by Dr. Fischer et al. [44],[45] In TECP the polishing pad also acts as one of the electrode and is metallic in nature. TECP due to its...

  20. Memristor using a transition metal nitride insulator

    DOE Patents [OSTI]

    Stevens, James E; Marinella, Matthew; Lohn, Andrew John

    2014-10-28T23:59:59.000Z

    Apparatus is disclosed in which at least one resistive switching element is interposed between at least a first and a second conducting electrode element. The resistive switching element comprises a metal oxynitride. A method for making such a resistive switching element is also disclosed.

  1. Metal-oxide-based energetic materials and synthesis thereof

    DOE Patents [OSTI]

    Tillotson, Thomas M. (Tracy, CA), Simpson; Randall L. (Livermore, CA); Hrubesh, Lawrence W. (Pleasanton, CA)

    2006-01-17T23:59:59.000Z

    A method of preparing energetic metal-oxide-based energetic materials using sol-gel chemistry has been invented. The wet chemical sol-gel processing provides an improvement in both safety and performance. Essentially, a metal-oxide oxidizer skeletal structure is prepared from hydrolyzable metals (metal salts or metal alkoxides) with fuel added to the sol prior to gelation or synthesized within the porosity metal-oxide gel matrix. With metal salt precursors a proton scavenger is used to destabilize the sol and induce gelation. With metal alkoxide precursors standard well-known sol-gel hydrolysis and condensation reactions are used. Drying is done by standard sol-gel practices, either by a slow evaporation of the liquid residing within the pores to produce a high density solid nanocomposite, or by supercritical extraction to produce a lower density, high porous nanocomposite. Other ingredients may be added to this basic nanostructure to change physical and chemical properties, which include organic constituents for binders or gas generators during reactions, burn rate modifiers, or spectral emitters.

  2. High temperature superconductivity in metallic region near Mott transition

    E-Print Network [OSTI]

    Tian De Cao

    2009-09-11T23:59:59.000Z

    The spin-singlet superconductivity without phonons is examined in consideration of correlations on an extended Hubbard model. It is shown that the superconductivity requires not only the total correlation should be strong enough but also the density of state around Fermi energy should be large enough, which shows that the high temperature superconductivity could only be found in the metallic region near the Mott metal insulator transition (MIT). Other properties of superconductors are also discussed on these conclusions.

  3. Aerosol chemical vapor deposition of metal oxide films

    DOE Patents [OSTI]

    Ott, K.C.; Kodas, T.T.

    1994-01-11T23:59:59.000Z

    A process of preparing a film of a multicomponent metal oxide including: forming an aerosol from a solution comprised of a suitable solvent and at least two precursor compounds capable of volatilizing at temperatures lower than the decomposition temperature of said precursor compounds; passing said aerosol in combination with a suitable oxygen-containing carrier gas into a heated zone, said heated zone having a temperature sufficient to evaporate the solvent and volatilize said precursor compounds; and passing said volatilized precursor compounds against the surface of a substrate, said substrate having a sufficient temperature to decompose said volatilized precursor compounds whereby metal atoms contained within said volatilized precursor compounds are deposited as a metal oxide film upon the substrate is disclosed. In addition, a coated article comprising a multicomponent metal oxide film conforming to the surface of a substrate selected from the group consisting of silicon, magnesium oxide, yttrium-stabilized zirconium oxide, sapphire, or lanthanum gallate, said multicomponent metal oxide film characterized as having a substantially uniform thickness upon said substrate.

  4. Ultrathin amorphous zinc-tin-oxide buffer layer for enhancing heterojunction interface quality in metal-oxide solar cells

    E-Print Network [OSTI]

    Heo, Jaeyeong

    We demonstrate a tunable electron-blocking layer to enhance the performance of an Earth-abundant metal-oxide solar-cell material. A 5 nm thick amorphous ternary metal-oxide buffer layer reduces interface recombination, ...

  5. Preparation of nanoporous metal foam from high nitrogen transition metal complexes

    DOE Patents [OSTI]

    Tappan, Bryce C.; Huynh, My Hang V.; Hiskey, Michael A.; Son, Steven F.; Oschwald, David M.; Chavez, David E.; Naud, Darren L.

    2006-11-28T23:59:59.000Z

    Nanoporous metal foams are prepared by ignition of high nitrogen transition metal complexes. The ammonium salts of iron(III) tris[bi(tetrazolato)-amine], cobalt(III) tris(bi(tetrazolato)amine), and high nitrogen compounds of copper and silver were prepared as loose powders, pressed into pellets and wafers, and ignited under an inert atmosphere to form nanoporous metal foam monoliths having very high surface area and very low density.

  6. Methods of making metal oxide nanostructures and methods of controlling morphology of same

    DOE Patents [OSTI]

    Wong, Stanislaus S; Hongjun, Zhou

    2012-11-27T23:59:59.000Z

    The present invention includes a method of producing a crystalline metal oxide nanostructure. The method comprises providing a metal salt solution and providing a basic solution; placing a porous membrane between the metal salt solution and the basic solution, wherein metal cations of the metal salt solution and hydroxide ions of the basic solution react, thereby producing a crystalline metal oxide nanostructure.

  7. Hall effect at a tunable metal-insulator transition

    E-Print Network [OSTI]

    Teizer, Winfried; Hellman, F.; Dynes, RC.

    2003-01-01T23:59:59.000Z

    Using a rotating magnetic field, the Hall effect in three-dimensional amorphous GdxSi1-x has been measured in the critical regime of the metal-insulator transition for a constant total magnetic field. The Hall coefficient R-0 is negative, indicating...

  8. Ethanol oxidation on metal oxide-supported platinum catalysts

    SciTech Connect (OSTI)

    L. M. Petkovic 090468; Sergey N. Rashkeev; D. M. Ginosar

    2009-09-01T23:59:59.000Z

    Ethanol is a renewable fuel that can be used as an additive to gasoline (or its substitute) with the advantage of octane enhancement and reduced carbon monoxide exhaust emissions. However, on Ethanol is a renewable fuel that can be used as an additive to gasoline (or its substitute) with the advantage of octane enhancement and reduced carbon monoxide exhaust emissions. However, on the standard three-way catalysts, the conversion of unburned ethanol is low because both ethanol and some of its partially oxidized derivatives are highly resistant to oxidation. A combination of first-principles density-functional theory (DFT) based calculations and in-situ diffuse reflectance infrared spectroscopy (DRIFTS) analysis was applied to uncover some of the fundamental phenomena associated with ethanol oxidation on Pt containing catalysts. In particular, the objective was to analyze the role of the oxide (i.e., ?-Al2O3 or SiO2) substrate on the ethanol oxidation activity. The results showed that Pt nanoparticles trap and accumulate oxygen at their surface and perimeter sites and play the role of “stoves” that burn ethanol molecules and their partially oxidized derivatives to the “final” products. The ?-Al2O3 surfaces provided higher mobility of the fragments of ethanol molecules than the SiO2 surface and hence increased the supply rate of these objects to the Pt particles. This will in turn produce a higher conversion rate of unburned ethanol.and some of its partially oxidized derivatives are highly resistant to oxidation. A combination of first-principles density-functional theory (DFT) based calculations and in-situ diffuse reflectance infrared spectroscopy (DRIFTS) analysis was applied to uncover some of the fundamental phenomena associated with ethanol oxidation on Pt containing catalysts. In particular, the objective was to analyze the role of the oxide (i.e., ?-Al2O3 or SiO2) substrate on the ethanol oxidation activity. The results showed that Pt nanoparticles trap and accumulate oxygen at their surface and perimeter sites and play the role of “stoves” that burn ethanol molecules and their partially oxidized derivatives to the “final” products. The ?-Al2O3 surfaces provided higher mobility of the fragments of ethanol molecules than the SiO2 surface and hence increased the supply rate of these objects to the Pt particles. This will in turn produce a higher conversion rate of unburned ethanol.

  9. Electrical characterization of native-oxide InAlPGaAs metal-oxide-semiconductor heterostructures using

    E-Print Network [OSTI]

    Electrical characterization of native-oxide InAlPÕGaAs metal-oxide-semiconductor heterostructures 8 December 2003; accepted 20 January 2004 InAIP native oxide/GaAs metal-oxide-semiconductor MOS of Schottky gates can lead to excessive gate leakage current and also restrict the forward gate bias to only

  10. E-Print Network 3.0 - acidic transition metals Sample Search...

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

    liquids, chlorates, nitrites, sulfur, finely... hypochlorite, all oxidizing agents Carbon tetrachloride Sodium Chlorates Ammonium salts, acids, powdered metals... , copper,...

  11. Computational Studies of the Electronic Structures and Mechanisms of Late Transition Metal Systems 

    E-Print Network [OSTI]

    Pitts, Amanda

    2013-08-27T23:59:59.000Z

    Late transition metal species are heavily studied because of their diverse applications in industrial, synthetic, and biological processes. Transition metals can alter the thermodynamic aspects of a reaction by creating ...

  12. Disordered electronic and magnetic systems - transition metal (Mn) and rare earth (Gd) doped amorphous group IV semiconductors (C, Si, Ge)

    E-Print Network [OSTI]

    Zeng, Li

    2007-01-01T23:59:59.000Z

    various transition or rare-earth metals provide a rich ?eldTransition Metal (Mn) and Rare Earth (Gd) Doped AmorphousTransition Metal (Mn) and Rare Earth (Gd) Doped Amorphous

  13. Criteria for safe storage of plutonium metals and oxides

    SciTech Connect (OSTI)

    Not Available

    1994-12-01T23:59:59.000Z

    This standard establishes safety criteria for safe storage of plutonium metals and plutonium oxides at DOE facilities; materials packaged to meet these criteria should not need subsequent repackaging to ensure safe storage for at least 50 years or until final disposition. The standard applied to Pu metals, selected alloys (eg., Ga and Al alloys), and stabilized oxides containing at least 50 wt % Pu; it does not apply to Pu-bearing liquids, process residues, waste, sealed weapon components, or material containing more than 3 wt % {sup 238}Pu. Requirements for a Pu storage facility and safeguards and security considerations are not stressed as they are addressed in detail by other DOE orders.

  14. Amorphous semiconducting and conducting transparent metal oxide thin films and production thereof

    DOE Patents [OSTI]

    Perkins, John (Boulder, CO); Van Hest, Marinus Franciscus Antonius Maria (Lakewood, CO); Ginley, David (Evergreen, CO); Taylor, Matthew (Golden, CO); Neuman, George A. (Holland, MI); Luten, Henry A. (Holland, MI); Forgette, Jeffrey A. (Hudsonville, MI); Anderson, John S. (Holland, MI)

    2010-07-13T23:59:59.000Z

    Metal oxide thin films and production thereof are disclosed. An exemplary method of producing a metal oxide thin film may comprise introducing at least two metallic elements and oxygen into a process chamber to form a metal oxide. The method may also comprise depositing the metal oxide on a substrate in the process chamber. The method may also comprise simultaneously controlling a ratio of the at least two metallic elements and a stoichiometry of the oxygen during deposition. Exemplary amorphous metal oxide thin films produced according to the methods herein may exhibit highly transparent properties, highly conductive properties, and/or other opto-electronic properties.

  15. Transition Metal Dimer Internuclear Distances from Measured Force Constants Joseph L. Jules and John R. Lombardi*

    E-Print Network [OSTI]

    Lombardi, John R.

    Transition Metal Dimer Internuclear Distances from Measured Force Constants Joseph L. Jules distances, have been extended to the transition metal dimers to test which one gives the most accurate fit's and Guggenheimer's for the transition metal dimers. Although Pauling's rule gives the best results, the remarkable

  16. Investigation of methods for the selective removal and characterization of transition metals associated with solids in the marine environment

    SciTech Connect (OSTI)

    Van Valin, R.; Morse, J.W.

    1981-02-01T23:59:59.000Z

    The operation of an OTEC plant will result in the mixing of large volumes of seawater from different depths within the ocean. Because suspended particulate material is intimately involved in marine food webs and transition metals, such as copper, can have toxic effects, it is important to develop a sound methodology for characterizing and quantifying transition metal behavior associated with the solid material. The characterization of solid-phase-associated transition metals in the marine environment has largely been directed at marine sediments. These studies have generally indicated that it is not possible to uniquely identify the solid phases or chemical speciation of a given metal. There are many reasons for this difficulty, but the probable major analytical problems arise from the fact that many of the transition metals of interest are present only in trace concentrations as adsorbed species on amorphous oxides or as coprecipitates. In one approach transition metals are classified according to how easily they are solubilized when exposed to different types of chemical attack, as defined in chemical extraction schemes. In this study, several of the most widely accepted extraction techniques were compared for many of the most commonly measured transition metals to a variety of marine sediments. Based on the results of this study, the sequential extraction scheme of Tessler et al. (1979) is the recommended method for the characterization of solid-phase associated transition metals. An increase of the reducing agent concentration in the intermediate step and temperature decrease with an additional HCl digestion in the residual step are recommended as improvements, based on the results of the individual extraction method studies.

  17. Design Principles for Oxygen-Reduction Activity on Perovskite Oxide Catalysts for Fuel Cells and Metal-air Batteries

    SciTech Connect (OSTI)

    J Suntivich; H Gasteiger; N Yabuuchi; H Nakanishi; J Goodenough; Y Shao-Horn

    2011-12-31T23:59:59.000Z

    The prohibitive cost and scarcity of the noble-metal catalysts needed for catalysing the oxygen reduction reaction (ORR) in fuel cells and metal-air batteries limit the commercialization of these clean-energy technologies. Identifying a catalyst design principle that links material properties to the catalytic activity can accelerate the search for highly active and abundant transition-metal-oxide catalysts to replace platinum. Here, we demonstrate that the ORR activity for oxide catalysts primarily correlates to {sigma}*-orbital (e{sub g}) occupation and the extent of B-site transition-metal-oxygen covalency, which serves as a secondary activity descriptor. Our findings reflect the critical influences of the {sigma}* orbital and metal-oxygen covalency on the competition between O{sub 2}{sup 2-}/OH{sup -} displacement and OH{sup -} regeneration on surface transition-metal ions as the rate-limiting steps of the ORR, and thus highlight the importance of electronic structure in controlling oxide catalytic activity.

  18. Metal current collect protected by oxide film

    DOE Patents [OSTI]

    Jacobson, Craig P. (Lafayette, CA); Visco, Steven J. (Berkeley, CA); DeJonghe, Lutgard C. (Lafayette, CA)

    2004-05-25T23:59:59.000Z

    Provided are low-cost, mechanically strong, highly electronically conductive current collects and associated structures for solid-state electrochemical devices, techniques for forming these structures, and devices incorporating the structures. The invention provides solid state electrochemical devices having as current interconnects a ferritic steel felt or screen coated with a protective oxide film.

  19. Is the chiral phase transition induced by a metal-insulator transition?

    E-Print Network [OSTI]

    Antonio M. Garcia-Garcia; James C. Osborn

    2007-11-18T23:59:59.000Z

    We investigate the QCD Dirac operator with gauge configurations given by a liquid of instantons in the region of temperatures about the chiral phase transition. Both the quenched and unquenched cases are examined in detail. We present evidence of a localization transition in the low lying modes of the Dirac operator around the same temperature as the chiral phase transition. Thus both level statistics and eigenvectors of the QCD Dirac operator at the chiral phase transition have similar properties than those of a disordered conductor at the metal-insulator transition. This strongly suggests the phenomenon of Anderson localization (localization by destructive quantum interference) is the leading physical mechanism in the restoration of the chiral symmetry. Finally we argue that our findings are not in principle restricted to the ILM approximation and may also be found in lattice simulations.

  20. EURODISPLAY 2002 631 P-64: A Comparative Study of Metal Oxide Coated Indium-tin Oxide Anodes

    E-Print Network [OSTI]

    EURODISPLAY 2002 631 P-64: A Comparative Study of Metal Oxide Coated Indium-tin Oxide Anodes and Technology Clear Water Bay, Kowloon, Hong Kong Abstract Indium-tin oxide anodes capped with certain oxides-emitting diodes (OLEDs). The oxides of tin, zinc, praseodymium, yttrium, gallium, terbium and titanium have been

  1. Structure of liquid transition and rare earth metals S. N. Khanna and F. Cyrot-Lackmann

    E-Print Network [OSTI]

    Boyer, Edmond

    L-45 Structure of liquid transition and rare earth metals S. N. Khanna and F. Cyrot-Lackmann Groupe It is shown that the observed structure factors of transition and rare earth liquid metals can be reaso- nably. The difference is particularly large for V, Ti, and rare earth metals which are precisely the metals where

  2. All-alkoxide synthesis of strontium-containing metal oxides

    DOE Patents [OSTI]

    Boyle, Timothy J. (Albuquerque, NM)

    2001-01-01T23:59:59.000Z

    A method for making strontium-containing metal-oxide ceramic thin films from a precursor liquid by mixing a strontium neo-pentoxide dissolved in an amine solvent and at least one metal alkoxide dissolved in a solvent, said at least one metal alkoxide selected from the group consisting of alkoxides of calcium, barium, bismuth, cadmium, lead, titanium, tantalum, hafnium, tungsten, niobium, zirconium, yttrium, lanthanum, antimony, chromium and thallium, depositing a thin film of the precursor liquid on a substrate, and heating the thin film in the presence of oxygen at between 550 and 700.degree. C.

  3. Exciton complexes in low dimensional transition metal dichalcogenides

    SciTech Connect (OSTI)

    Thilagam, A., E-mail: thilaphys@gmail.com [Information Technology, Engineering and Environment, University of South Australia, Adelaide 5095 (Australia)

    2014-08-07T23:59:59.000Z

    We examine the excitonic properties of layered configurations of low dimensional transition metal dichalcogenides (LTMDCs) using the fractional dimensional space approach. The binding energies of the exciton, trion, and biexciton in LTMDCs of varying layers are analyzed, and linked to the dimensionality parameter ?, which provides insight into critical electro-optical properties (relative oscillator strength, absorption spectrum, exciton-exciton interaction) of the material systems. The usefulness of ? is highlighted by its independence of the physical mechanisms underlying the confinement effects of geometrical structures. Our estimates of the binding energies of exciton complexes for the monolayer configuration of transition metal dichalcogenides suggest a non-collinear structure for the trion and a positronium-molecule-like square structure for the biexciton.

  4. Ductile-to-brittle transition in spallation of metallic glasses

    SciTech Connect (OSTI)

    Huang, X. [State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China); Institute of Systems Engineering, China Academy of Engineering Physics, Mianyang, Sichuan 621999 (China); Ling, Z. [State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China); Dai, L. H., E-mail: lhdai@lnm.imech.ac.cn [State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China); State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 10081 (China)

    2014-10-14T23:59:59.000Z

    In this paper, the spallation behavior of a binary metallic glass Cu{sub 50}Zr{sub 50} is investigated with molecular dynamics simulations. With increasing the impact velocity, micro-voids induced by tensile pulses become smaller and more concentrated. The phenomenon suggests a ductile-to-brittle transition during the spallation process. Further investigation indicates that the transition is controlled by the interaction between void nucleation and growth, which can be regarded as a competition between tension transformation zones (TTZs) and shear transformation zones (STZs) at atomic scale. As impact velocities become higher, the stress amplitude and temperature rise in the spall region increase and micro-structures of the material become more unstable. Therefore, TTZs are prone to activation in metallic glasses, leading to a brittle behavior during the spallation process.

  5. Zwitterionic Group VIII transition metal initiators supported by olefin ligands

    DOE Patents [OSTI]

    Bazan, Guillermo C. (Goleta, CA); Chen, Yaofeng (Shanghai, CN)

    2011-10-25T23:59:59.000Z

    A zwitterionic Group VIII transition metal complex containing the simple and relatively small 3-(arylimino)-but-1-en-2-olato ligand that catalyzes the formation of polypropylene and high molecular weight polyethylene. A novel feature of this catalyst is that the active species is stabilized by a chelated olefin adduct. The present invention also provides methods of polymerizing olefin monomers using zwitterionic catalysts, particularly polypropylene and high molecular weight polyethylene.

  6. Transition-metal doped sulfide, selenide, and telluride laser crystal and lasers

    DOE Patents [OSTI]

    Krupke, William F. (Pleasanton, CA); Page, Ralph H. (San Ramon, CA); DeLoach, Laura D. (Manteca, CA); Payne, Stephen A. (Castro Valley, CA)

    1996-01-01T23:59:59.000Z

    A new class of solid state laser crystals and lasers are formed of transition metal doped sulfide, selenide, and telluride host crystals which have four fold coordinated substitutional sites. The host crystals include II-VI compounds. The host crystal is doped with a transition metal laser ion, e.g., chromium, cobalt or iron. In particular, Cr.sup.2+ -doped ZnS and ZnSe generate laser action near 2.3 .mu.m. Oxide, chloride, fluoride, bromide and iodide crystals with similar structures can also be used. Important aspects of these laser materials are the tetrahedral site symmetry of the host crystal, low excited state absorption losses and high luminescence efficiency, and the d.sup.4 and d.sup.6 electronic configurations of the transition metal ions. The same materials are also useful as saturable absorbers for passive Q-switching applications. The laser materials can be used as gain media in amplifiers and oscillators; these gain media can be incorporated into waveguides and semiconductor lasers.

  7. Transition-metal doped sulfide, selenide, and telluride laser crystal and lasers

    DOE Patents [OSTI]

    Krupke, W.F.; Page, R.H.; DeLoach, L.D.; Payne, S.A.

    1996-07-30T23:59:59.000Z

    A new class of solid state laser crystals and lasers are formed of transition metal doped sulfide, selenide, and telluride host crystals which have four fold coordinated substitutional sites. The host crystals include II-VI compounds. The host crystal is doped with a transition metal laser ion, e.g., chromium, cobalt or iron. In particular, Cr{sup 2+}-doped ZnS and ZnSe generate laser action near 2.3 {micro}m. Oxide, chloride, fluoride, bromide and iodide crystals with similar structures can also be used. Important aspects of these laser materials are the tetrahedral site symmetry of the host crystal, low excited state absorption losses and high luminescence efficiency, and the d{sup 4} and d{sup 6} electronic configurations of the transition metal ions. The same materials are also useful as saturable absorbers for passive Q-switching applications. The laser materials can be used as gain media in amplifiers and oscillators; these gain media can be incorporated into waveguides and semiconductor lasers. 18 figs.

  8. Stability and Aggregation of Metal Oxide Nanoparticles in Natural

    E-Print Network [OSTI]

    Cardinale, Bradley J.

    dispersed three different metal oxide nanoparticles (TiO2, ZnO and CeO2) in samples taken from eight,river,andgroundwater,andmeasuredtheirelectrophoretic mobility, state of aggregation, and rate of sedimentation.g., sunscreens, paints, coatings, catalysts). A simplified con- ceptual model of a typical nanoparticle life

  9. Volatile organometallic complexes suitable for use in chemical vapor depositions on metal oxide films

    DOE Patents [OSTI]

    Giolando, Dean M.

    2003-09-30T23:59:59.000Z

    Novel ligated compounds of tin, titanium, and zinc are useful as metal oxide CVD precursor compounds without the detriments of extreme reactivity yet maintaining the ability to produce high quality metal oxide coating by contact with heated substrates.

  10. Production of Oxygen Gas and Liquid Metal by Electrochemical Decomposition of Molten Iron Oxide

    E-Print Network [OSTI]

    Wang, Dihua

    Molten oxide electrolysis (MOE) is the electrolytic decomposition of a metal oxide, most preferably into liquid metal and oxygen gas. The successful deployment of MOE hinges upon the existence of an inert anode capable of ...

  11. Electrical excitation of colloidally synthesized quantum dots in metal oxide structures

    E-Print Network [OSTI]

    Wood, Vanessa Claire

    2010-01-01T23:59:59.000Z

    This thesis develops methods for integrating colloidally synthesized quantum dots (QDs) and metal oxides in optoelectronic devices, presents three distinct light emitting devices (LEDs) with metal oxides surrounding a QD ...

  12. Thin Metal Oxide Films to Modify a Window Layer in CdTe-Based...

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

    Thin Metal Oxide Films to Modify a Window Layer in CdTe-Based Solar Cells for Improved Performance. Thin Metal Oxide Films to Modify a Window Layer in CdTe-Based Solar Cells for...

  13. Method for treating rare earth-transition metal scrap

    DOE Patents [OSTI]

    Schmidt, Frederick A. (Ames, IA); Peterson, David T. (Ames, IA); Wheelock, John T. (Nevada, IA); Jones, Lawrence L. (Des Moines, IA)

    1992-12-29T23:59:59.000Z

    Rare earth-transition metal (e.g., iron) scrap (e.g., Nd-Fe-B scrap) is flux (slag) remelted to reduce tramp non-metallic impurities, such as oxygen and nitrogen, and metallic impurities, such as Li, Na, Al, etc., picked up by the scrap from previous fabrication operations. The tramp impurities are reduced to concentrations acceptable for reuse of the treated alloy in the manufacture of end-use articles, such as permanent magnets. The scrap is electroslag or inductoslag melted using a prefused, rare earth fluoride-bearing flux of CaF.sub.2, CaCl.sub.2 or mixtures thereof or the slag resulting from practice of the thermite reduction process to make a rare earth-iron alloy.

  14. Method for treating rare earth-transition metal scrap

    DOE Patents [OSTI]

    Schmidt, F.A.; Peterson, D.T.; Wheelock, J.T.; Jones, L.L.

    1992-12-29T23:59:59.000Z

    Rare earth-transition metal (e.g., iron) scrap (e.g., Nd-Fe-B scrap) is flux (slag) remelted to reduce tramp non-metallic impurities, such as oxygen and nitrogen, and metallic impurities, such as Li, Na, Al, etc., picked up by the scrap from previous fabrication operations. The tramp impurities are reduced to concentrations acceptable for reuse of the treated alloy in the manufacture of end-use articles, such as permanent magnets. The scrap is electroslag or inductoslag melted using a rare earth fluoride-bearing flux of CaF[sub 2], CaCl[sub 2] or mixtures thereof or the slag resulting from practice of the thermite reduction process to make a rare earth-iron alloy. 3 figs.

  15. Catalytic oxidation of CO by platinum group metals: from ultrahigh vacuum to elevated pressures

    E-Print Network [OSTI]

    Goodman, Wayne

    oxidation over platinum group metals has been investigated for some eight decades by many researchersCatalytic oxidation of CO by platinum group metals: from ultrahigh vacuum to elevated pressures A Catalytic oxidation of CO over platinum group metals (Pt, Ir, Rh and Pd) has been the subject of many

  16. Nanotube Formation: Researchers Learn To Control The Dimensions Of Metal Oxide Nanotubes

    E-Print Network [OSTI]

    Nair, Sankar

    made from metal oxides -- work that could lead to a technique for precisely conNanotube Formation: Researchers Learn To Control The Dimensions Of Metal Oxide Nanotubes Science their diameter and length. Based on metal oxides in combination with silicon and germanium, such single

  17. Deactivation and regeneration of a promoted transition-metal-zeolite catalyst

    SciTech Connect (OSTI)

    Pennline, H.W.; Pollack, S.S.

    1986-03-01T23:59:59.000Z

    The regeneration of a promoted transition-metal-zeolite catalyst that had been used to convert synthesis gas to gasoline-range hydrocarbons was investigated in a mixed reactor system. Carbonaceous deposits were found on the catalyst-a coprecipitated cobalt-thoria admixed with ZSM-5 zeolite-after it has been subjected to low hydrogen to carbon monoxide ratio synthesis gas at the processing conditions. Oxidative regenerations did not succeed in returning the catalyst to its initial synthesis activity. X-ray diffraction analysis of the used and regenerated catalyst samples suggested that sintering of the cobalt occurred. The crystallite size of the Co/sub 3/O/sub 4/ formed after regeneration was inversely related to the synthesis gas conversion after reduction of the Co/sub 3/O/sub 4/ to the metal.

  18. Production of Oxygen Gas and Liquid Metal by Electrochemical Decomposition of Molten Iron Oxide

    E-Print Network [OSTI]

    Sadoway, Donald Robert

    on the moon and on Mars for the generation of oxygen along with the production of structural metalsProduction of Oxygen Gas and Liquid Metal by Electrochemical Decomposition of Molten Iron Oxide) is the electrolytic decomposition of a metal oxide, most preferably into liquid metal and oxygen gas. The successful

  19. Cyclic catalytic upgrading of chemical species using metal oxide materials

    DOE Patents [OSTI]

    White, James H; Schutte, Erick J; Rolfe, Sara L

    2013-05-07T23:59:59.000Z

    Processes are disclosure which comprise alternately contacting an oxygen-carrying catalyst with a reducing substance, or a lower partial pressure of an oxidizing gas, and then with the oxidizing gas or a higher partial pressure of the oxidizing gas, whereby the catalyst is alternately reduced and then regenerated to an oxygenated state. In certain embodiments, the oxygen-carrying catalyst comprises at least one metal oxide-containing material containing a composition having the following formulas: (a) Ce.sub.xB.sub.yB'.sub.zB''O.sub..delta., wherein B=Ba, Sr, Ca, or Zr; B'=Mn, Co, and/or Fe; B''=Cu; 0.01metal oxides.

  20. Influence of uranium hydride oxidation on uranium metal behaviour

    SciTech Connect (OSTI)

    Patel, N.; Hambley, D. [National Nuclear Laboratory (United Kingdom); Clarke, S.A. [Sellafield Ltd (United Kingdom); Simpson, K.

    2013-07-01T23:59:59.000Z

    This work addresses concerns that the rapid, exothermic oxidation of active uranium hydride in air could stimulate an exothermic reaction (burning) involving any adjacent uranium metal, so as to increase the potential hazard arising from a hydride reaction. The effect of the thermal reaction of active uranium hydride, especially in contact with uranium metal, does not increase in proportion with hydride mass, particularly when considering large quantities of hydride. Whether uranium metal continues to burn in the long term is a function of the uranium metal and its surroundings. The source of the initial heat input to the uranium, if sufficient to cause ignition, is not important. Sustained burning of uranium requires the rate of heat generation to be sufficient to offset the total rate of heat loss so as to maintain an elevated temperature. For dense uranium, this is very difficult to achieve in naturally occurring circumstances. Areas of the uranium surface can lose heat but not generate heat. Heat can be lost by conduction, through contact with other materials, and by convection and radiation, e.g. from areas where the uranium surface is covered with a layer of oxidised material, such as burned-out hydride or from fuel cladding. These rates of heat loss are highly significant in relation to the rate of heat generation by sustained oxidation of uranium in air. Finite volume modelling has been used to examine the behaviour of a magnesium-clad uranium metal fuel element within a bottle surrounded by other un-bottled fuel elements. In the event that the bottle is breached, suddenly, in air, it can be concluded that the bulk uranium metal oxidation reaction will not reach a self-sustaining level and the mass of uranium oxidised will likely to be small in relation to mass of uranium hydride oxidised. (authors)

  1. Catalytic graphitization of carbon aerogels by transition metals

    SciTech Connect (OSTI)

    Maldonado-Hodar, F.J.; Moreno-Castilla, C.; Rivera-Utrilla, J.; Hanzawa, Y.; Yamada, Y.

    2000-05-02T23:59:59.000Z

    Carbon aerogels and Cr-, Fe-, Co-, and Ni-containing carbon aerogels were obtained by pyrolysis, at temperatures between 500 and 1,800 C, of the corresponding aerogels prepared by the sol-gel method from polymerization of resorcinol with formaldehyde. All samples were characterized by mercury porosimetry, nitrogen adsorption, X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and Raman spectroscopy. Results obtained show that carbon aerogels are, essentially, macroporous materials that maintain large pore volumes even after pyrolysis at 1,800 C. For pyrolysis at temperatures higher than 1,000 C, the presence of the transition metals produced graphitized areas with three-dimensional stacking order, as shown by HRTEM, XRD, and Raman spectroscopy. HRTEM also showed that the metal-carbon containing aerogels were formed by polyhedral structures. Cr and Fe seem to be the best catalysts for graphitization of carbon aerogels.

  2. Synthesis of metal-metal oxide catalysts and electrocatalysts using a metal cation adsorption/reduction and adatom replacement by more noble ones

    DOE Patents [OSTI]

    Adzic, Radoslav; Vukmirovic, Miomir; Sasaki, Kotaro

    2010-04-27T23:59:59.000Z

    The invention relates to platinum-metal oxide composite particles and their use as electrocatalysts in oxygen-reducing cathodes and fuel cells. The invention particularly relates to methods for preventing the oxidation of the platinum electrocatalyst in the cathodes of fuel cells by use of these platinum-metal oxide composite particles. The invention additionally relates to methods for producing electrical energy by supplying such a fuel cell with an oxidant, such as oxygen, and a fuel source, such as hydrogen. The invention also relates to methods of making the metal-metal oxide composites.

  3. Metal-insulator Transition by Holographic Charge Density Waves

    E-Print Network [OSTI]

    Yi Ling; Chao Niu; Jianpin Wu; Zhuoyu Xian; Hongbao Zhang

    2014-08-06T23:59:59.000Z

    We construct a gravity dual for charge density waves (CDW) in which the translational symmetry along one spatial direction is spontaneously broken. Our linear perturbation calculation on the gravity side produces the frequency dependence of the optical conductivity, which exhibits the two familiar features of charge density waves, namely the pinned collective mode and gapped single-particle excitation. These two features indicate that our gravity dual also provides a new mechanism to implement the metal to insulator phase transition by CDW, which is further supported by the fact that d.c. conductivity decreases with the decreased temperature below the critical temperature.

  4. Rare earth-transition metal scrap treatment method

    DOE Patents [OSTI]

    Schmidt, F.A.; Peterson, D.T.; Wheelock, J.T.; Jones, L.L.; Lincoln, L.P.

    1992-02-11T23:59:59.000Z

    Rare earth-transition metal (e.g. iron) scrap (e.g. Nd-Fe-B scrap) is melted to reduce the levels of tramp oxygen and nitrogen impurities therein. The tramp impurities are reduced in the melt by virtue of the reaction of the tramp impurities and the rare earth to form dross on the melt. The purified melt is separated from the dross for reuse. The oxygen and nitrogen of the melt are reduced to levels acceptable for reuse of the treated alloy in the manufacture of end-use articles, such as permanent magnets. 3 figs.

  5. Rare earth-transition metal scrap treatment method

    DOE Patents [OSTI]

    Schmidt, Frederick A. (Ames, IA); Peterson, David T. (Ames, IA); Wheelock, John T. (Nevada, IA); Jones, Lawrence L. (Des Moines, IA); Lincoln, Lanny P. (Woodward, IA)

    1992-02-11T23:59:59.000Z

    Rare earth-transition metal (e.g. iron) scrap (e.g. Nd-Fe-B scrap) is melted to reduce the levels of tramp oxygen and nitrogen impurities therein. The tramp impurities are reduced in the melt by virtue of the reaction of the tramp impurities and the rare earth to form dross on the melt. The purified melt is separated from the dross for reuse. The oxygen and nitrogen of the melt are reduced to levels acceptable for reuse of the treated alloy in the manufacture of end-use articles, such as permanent magnets.

  6. For cermet inert anode containing oxide and metal phases useful for the electrolytic production of metals

    DOE Patents [OSTI]

    Ray, Siba P. (Murrysville, PA); Liu, Xinghua (Monroeville, PA); Weirauch, Douglas A. (Murrysville, PA)

    2002-01-01T23:59:59.000Z

    A cermet inert anode for the electrolytic production of metals such as aluminum is disclosed. The inert anode comprises a ceramic phase including an oxide of Ni, Fe and M, where M is at least one metal selected from Zn, Co, Al, Li, Cu, Ti, V, Cr, Zr, Nb, Ta, W, Mo, Hf and rare earths, preferably Zn and/or Co. Preferred ceramic compositions comprise Fe.sub.2 O.sub.3, NiO and ZnO or CoO. The cermet inert anode also comprises a metal phase such as Cu, Ag, Pd, Pt, Au, Rh, Ru, Ir and/or Os. A preferred metal phase comprises Cu and Ag. The cermet inert anodes may be used in electrolytic reduction cells for the production of commercial purity aluminum as well as other metals.

  7. Strengthening of metallic alloys with nanometer-size oxide dispersions

    DOE Patents [OSTI]

    Flinn, John E. (Idaho Falls, ID); Kelly, Thomas F. (Madison, WI)

    1999-01-01T23:59:59.000Z

    Austenitic stainless steels and nickel-base alloys containing, by wt. %, 0.1 to 3.0% V, 0.01 to 0.08% C, 0.01 to 0.5% N, 0.05% max. each of Al and Ti, and 0.005 to 0.10% O, are strengthened and ductility retained by atomization of a metal melt under cover of an inert gas with added oxygen to form approximately 8 nanometer-size hollow oxides within the alloy grains and, when the alloy is aged, strengthened by precipitation of carbides and nitrides nucleated by the hollow oxides. Added strengthening is achieved by nitrogen solid solution strengthening and by the effect of solid oxides precipitated along and pinning grain boundaries to provide temperature-stabilization and refinement of the alloy grains.

  8. Lithium metal oxide electrodes for lithium cells and batteries

    DOE Patents [OSTI]

    Thackeray, Michael M.; Johnson, Christopher S.; Amine, Khalil; Kim, Jaekook

    2006-11-14T23:59:59.000Z

    A lithium metal oxide positive electrode for a non-aqueous lithium cell is disclosed. The cell is prepared in its initial discharged state and has a general formula xLiMO2.(1-x)Li2M'O3 in which 0oxidation state and with at least one ion being Ni, and where M' is one or more ions with an average tetravalent oxidation state. Complete cells or batteries are disclosed with anode, cathode and electrolyte as are batteries of several cells connected in parallel or series or both.

  9. Lithium Metal Oxide Electrodes For Lithium Cells And Batteries

    DOE Patents [OSTI]

    Thackeray, Michael M. (Naperville, IL); Johnson, Christopher S. (Naperville, IL); Amine, Khalil (Downers Grove, IL); Kim, Jaekook (Naperville, IL)

    2004-01-20T23:59:59.000Z

    A lithium metal oxide positive electrode for a non-aqueous lithium cell is disclosed. The cell is prepared in its initial discharged state and has a general formula xLiMO.sub.2.(1-x)Li.sub.2 M'O.sub.3 in which 0oxidation state and with at least one ion being Mn or Ni, and where M' is one or more ion with an average tetravalent oxidation state. Complete cells or batteries are disclosed with anode, cathode and electrolyte as are batteries of several cells connected in parallel or series or both.

  10. Lithium metal oxide electrodes for lithium cells and batteries

    DOE Patents [OSTI]

    Thackeray, Michael M. (Naperville, IL); Johnson, Christopher S. (Naperville, IL); Amine, Khalil (Oakbrook, IL)

    2008-12-23T23:59:59.000Z

    A lithium metal oxide positive electrode for a non-aqueous lithium cell is disclosed. The cell is prepared in its initial discharged state and has a general formula xLiMO.sub.2.(1-x)Li.sub.2M'O.sub.3 in which 0oxidation state and with at least one ion being Mn or Ni, and where M' is one or more ion with an average tetravalent oxidation state. Complete cells or batteries are disclosed with anode, cathode and electrolyte as are batteries of several cells connected in parallel or series or both.

  11. Strengthening of metallic alloys with nanometer-size oxide dispersions

    DOE Patents [OSTI]

    Flinn, J.E.; Kelly, T.F.

    1999-06-01T23:59:59.000Z

    Austenitic stainless steels and nickel-base alloys containing, by wt. %, 0.1 to 3.0% V, 0.01 to 0.08% C, 0.01 to 0.5% N, 0.05% max. each of Al and Ti, and 0.005 to 0.10% O, are strengthened and ductility retained by atomization of a metal melt under cover of an inert gas with added oxygen to form approximately 8 nanometer-size hollow oxides within the alloy grains and, when the alloy is aged, strengthened by precipitation of carbides and nitrides nucleated by the hollow oxides. Added strengthening is achieved by nitrogen solid solution strengthening and by the effect of solid oxides precipitated along and pinning grain boundaries to provide temperature-stabilization and refinement of the alloy grains. 20 figs.

  12. Reactions of S-nitrosothiols with biomimetic iron complexes and other transition metals

    E-Print Network [OSTI]

    Victor, Eric, Ph. D. Massachusetts Institute of Technology

    2014-01-01T23:59:59.000Z

    Chapter 1. Bioinorganic Chemistry of Nitric Oxide and S-Nitrosothiols The interplay of nitric oxide (NO), biological thiols, and metals has been a topic of intense study since the discovery of NO as the endothelium-derived ...

  13. Performance of metal and oxide fuels during accidents in a large liquid metal cooled reactor

    SciTech Connect (OSTI)

    Cahalan, J.; Wigeland, R. (Argonne National Lab., IL (USA)); Friedel, G. (Internationale Atomreaktorbau GmbH (INTERATOM), Bergisch Gladbach (Germany, F.R.)); Kussmaul, G.; Royl, P. (Kernforschungszentrum Karlsruhe GmbH (Germany, F.R.)); Moreau, J. (CEA Centre d'Etudes Nucleaires de Cadarache, 13 - Saint-Paul-lez-Durance (France)); Perks, M. (UKAEA Risley Nuclear Power Development Establishment (UK)

    1990-01-01T23:59:59.000Z

    In a cooperative effort among European and US analysts, an assessment of the comparative safety performance of metal and oxide fuels during accidents in a large (3500 MWt), pool-type, liquid-metal-cooled reactor (LMR) was performed. The study focused on three accident initiators with failure to scram: the unprotected loss-of-flow (ULOF), the unprotected transient overpower (UTOP), and the unprotected loss-of-heat-sink (ULOHS). Emphasis was placed on identification of design features that provide passive, self-limiting responses to upset conditions, and quantification of relative safety margins. The analyses show that in ULOF and ULOHS sequences, metal-fueled LMRs with pool-type primary systems provide larger temperature margins to coolant boiling than oxide-fueled reactors of the same design. 3 refs., 4 figs.

  14. Anderson metal-insulator transitions with classical magnetic impurities

    SciTech Connect (OSTI)

    Jung, Daniel [School of Engineering and Science, Jacobs University Bremen gGmbH, Campus Ring 1, 28759 Bremen, Germany and Division of Advanced Materials Science, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Nam-gu, Pohang 790-784 (Korea, Republic of); Kettemann, Stefan [School of Engineering and Science, Jacobs University Bremen gGmbH,Campus Ring 1, 28759 Bremen, Germany and Division of Advanced Materials Science, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Nam-gu, Pohang 790-784 (Korea, Republic of)

    2014-08-20T23:59:59.000Z

    We study the effects of classical magnetic impurities on the Anderson metal-insulator transition (AMIT) numerically. In particular we find that while a finite concentration of Ising impurities lowers the critical value of the site-diagonal disorder amplitude W{sub c}, in the presence of Heisenberg impurities, W{sub c} is first increased with increasing exchange coupling strength J due to time-reversal symmetry breaking. The resulting scaling with J is compared to analytical predictions by Wegner [1]. The results are obtained numerically, based on a finite-size scaling procedure for the typical density of states [2], which is the geometric average of the local density of states. The latter can efficiently be calculated using the kernel polynomial method [3]. Although still suffering from methodical shortcomings, our method proves to deliver results close to established results for the orthogonal symmetry class [4]. We extend previous approaches [5] by combining the KPM with a finite-size scaling analysis. We also discuss the relevance of our findings for systems like phosphor-doped silicon (Si:P), which are known to exhibit a quantum phase transition from metal to insulator driven by the interplay of both interaction and disorder, accompanied by the presence of a finite concentration of magnetic moments [6].

  15. Synthesis, structure and properties of high pressure and ambient pressure ternary vanadium oxides 

    E-Print Network [OSTI]

    Markkula, Mikael

    2013-11-28T23:59:59.000Z

    Transition metal oxides have been extensively studied during past decades. The purpose of this research was to synthesize new or little characterised transition metal oxides using high-pressure/high-temperature (HPHT) ...

  16. Metal/metal oxide doped oxide catalysts having high deNOx selectivity for lean NOx exhaust aftertreatment systems

    DOE Patents [OSTI]

    Park, Paul W.

    2004-03-16T23:59:59.000Z

    A lean NOx catalyst and method of preparing the same is disclosed. The lean NOx catalyst includes a ceramic substrate, an oxide support material, preferably .gamma.-alumina, deposited on the substrate and a metal promoter or dopant introduced into the oxide support material. The metal promoters or dopants are selected from the group consisting of indium, gallium, tin, silver, germanium, gold, nickel, cobalt, copper, iron, manganese, molybdenum, chromium, cerium, vanadium, oxides thereof, and combinations thereof. The .gamma.-alumina preferably has a pore volume of from about 0.5 to about 2.0 cc/g; a surface area of between about 80 to 350 m.sup.2 /g; an average pore size diameter of between about 3 to 30 nm; and an impurity level of less than or equal to 0.2 weight percent. In a preferred embodiment the .gamma.-alumina is prepared by a sol-gel method, with the metal doping of the .gamma.-alumina preferably accomplished using an incipient wetness impregnation technique.

  17. Optical limiting of layered transition metal dichalcogenide semiconductors

    E-Print Network [OSTI]

    Dong, Ningning; Feng, Yanyan; Zhang, Saifeng; Zhang, Xiaoyan; Chang, Chunxia; Fan, Jintai; Zhang, Long; Wang, Jun

    2015-01-01T23:59:59.000Z

    Nonlinear optical property of transition metal dichalcogenide (TMDC) nanosheet dispersions, including MoS2, MoSe2, WS2, and WSe2, was performed by using Z-scan technique with ns pulsed laser at 1064 nm and 532 nm. The results demonstrate that the TMDC dispersions exhibit significant optical limiting response at 1064 nm due to nonlinear scattering, in contrast to the combined effect of both saturable absorption and nonlinear scattering at 532 nm. Selenium compounds show better optical limiting performance than that of the sulfides in the near infrared. A liquid dispersion system based theoretical modelling is proposed to estimate the number density of the nanosheet dispersions, the relationship between incident laser fluence and the size of the laser generated micro-bubbles, and hence the Mie scattering-induced broadband optical limiting behavior in the TMDC dispersions.

  18. Process studies with a promoted transition metal-zeolite catalyst

    SciTech Connect (OSTI)

    Pennline, H.W.; Gormley, R.J.; Schehl, R.R.

    1984-09-01T23:59:59.000Z

    The conversion of synthesis gas to gasoline-range hydrocarbons was investigated with a cobalt-thoria-zeolite catalyst. The coprecipitated transition metal and promoter were intimately mixed with ZSM-5 zeolite and then extruded with an alumina binder. Tests were conducted in a gradientless reactor, where initial results of high yields of gasoline-range hydrocarbons with a low ratio synthesis gas led to an extensive study of the catalyst. The effects of support, temperature (220-320C), pressure (1.14-2.17 MPa), and feed gas composition (1H2/1CO-3H2/1CO) on catalyst activity, stability, and product selectivity are discussed. Analyses of the deactivated bifunctional catalyst are also reported.

  19. Selective Catalytic Oxidation (SCO) of NH3 to N2 for Hot Exhaust...

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

    Oxidation (SCO) of NH3 to N2 for Hot Exhaust Treatment Investigation of a series of transition metal oxides and precious metal based catalysts for ammonia selective oxidation at...

  20. Cyclic catalytic upgrading of chemical species using metal oxide materials

    DOE Patents [OSTI]

    White, James H. (Boulder, CO); Schutte, Erick J. (Thornton, CO); Rolfe, Sara L. (Loveland, CO)

    2010-11-02T23:59:59.000Z

    Processes are disclosure which comprise alternately contacting an oxygen-carrying catalyst with a reducing substance, or a lower partial pressure of an oxidizing gas, and then with the oxidizing gas or a higher partial pressure of the oxidizing gas, whereby the catalyst is alternately reduced and then regenerated to an oxygenated state. In certain embodiments, the oxygen-carrying catalyst comprises at least one metal oxide-containing material containing a composition having one of the following formulas: (a) Ce.sub.xB.sub.yB'.sub.zB''O.sub..delta., wherein B=Ba, Sr, Ca, or Zr; B'=Mn, Co, or Fe; B''=Cu; 0.01

  1. THE MICROSTRUCTURAL LOCATION OF THE INTERGRANULAR METAL OXIDE PHASE IN A ZINC OXIDE VARISTOR

    E-Print Network [OSTI]

    Clarke, D. E

    2011-01-01T23:59:59.000Z

    OXIDE PHASE IN A ZINC OXIDE VARISTOR MICROSI'RUCTIJRALMETAL OXIDE PHASE IN A ZINC OXIDE VARISTOR David R. Clarke

  2. Lithium metal oxide electrodes for lithium cells and batteries

    DOE Patents [OSTI]

    Thackeray, Michael M. (Naperville, IL); Johnson, Christopher S. (Naperville, IL); Amine, Khalil (Downers Grove, IL); Kim, Jaekook (Naperville, IL)

    2004-01-13T23:59:59.000Z

    A lithium metal oxide positive electrode for a non-aqueous lithium cell is disclosed. The cell is prepared in its initial discharged state and has a general formula xLiMO.sub.2.(1-x)Li.sub.2 M'O.sub.3 in which 0

  3. A Low Temperature Fully Lithographic Process For Metal–Oxide Field-Effect Transistors

    E-Print Network [OSTI]

    Sodini, Charles G.

    We report a low temperature ( ~ 100à °C) lithographic method for fabricating hybrid metal oxide/organic field-effect transistors (FETs) that combine a zinc-indium-oxide (ZIO) semiconductor channel and organic, parylene, ...

  4. X-ray Absorption Spectroscopy of Transition Metal-Magnesium Hydride Thin Films

    E-Print Network [OSTI]

    X-ray Absorption Spectroscopy of Transition Metal-Magnesium Hydride Thin Films T. J. Richardsona@lbl.gov Abstract Mixed metal thin films containing magnesium and a first-row transition element exhibit very large of magnesium hydride. Keywords: A. hydrogen storage materials, thin films; C. EXAFS, NEXAFS, X-ray diffraction

  5. Sandia National Laboratories: electronic conducting transition...

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

    electronic conducting transition metal oxides Joint Hire Increases Materials Science Collaboration for Sandia, UNM On September 16, 2014, in Advanced Materials Laboratory,...

  6. Compositional Tuning of Ultrathin Surface Oxides on Metal and...

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

    that the native oxide on 5%Ni-Al alloy is primarily composed of aluminum oxide with no nickel oxide whereas the photon-assisted oxide comprises of both aluminum oxide and nickel...

  7. Modeling and experimental studies of oxide covered metal surfaces: TiO{sub 2}/Ti a model system. Progress report

    SciTech Connect (OSTI)

    Smyrl, W.H.

    1991-12-31T23:59:59.000Z

    Prior work in our laboratories at the Corrosion Research Center has shown that thin, anodic TiO{sub 2} films formed by the Slow Growth Mode (SGM) on polycrystalline titanium and microcrystalline with a texture that varies from one metal grain to another. Furthermore, the underlying metal grains are mapped by the photoelectrochemical response of the oxide. The same characteristics have also been demonstrated in our laboratory for ZnO grown on Zn. The TiO{sub 2}/Ti system has been chosen for study both because of its importance in energy systems, and because it can serve as a model system for other metal-metal oxide couples. The investigations of anodic TiO{sub 2} films on Ti have shown that the properties of thin films are consistent with the rutile form of the oxide. Both experimental data and theoretical calculations show the close resemblance to results on single crystal TiO{sub 2}. Furthermore, the modeling studies reveal that the optical transitions near the bandedge arise from the bulk band structure. The photoelectrochemical properties of anodic TiO{sub 2} films have now been shown to obey the simple Gaertner-Butler model for the semiconductor-electrolyte interface, with a few modifications. The most important deviation has now been shown to be a result of multiple internal reflections in the oxide film.

  8. Modeling and experimental studies of oxide covered metal surfaces: TiO sub 2 /Ti a model system

    SciTech Connect (OSTI)

    Smyrl, W.H.

    1991-01-01T23:59:59.000Z

    Prior work in our laboratories at the Corrosion Research Center has shown that thin, anodic TiO{sub 2} films formed by the Slow Growth Mode (SGM) on polycrystalline titanium and microcrystalline with a texture that varies from one metal grain to another. Furthermore, the underlying metal grains are mapped by the photoelectrochemical response of the oxide. The same characteristics have also been demonstrated in our laboratory for ZnO grown on Zn. The TiO{sub 2}/Ti system has been chosen for study both because of its importance in energy systems, and because it can serve as a model system for other metal-metal oxide couples. The investigations of anodic TiO{sub 2} films on Ti have shown that the properties of thin films are consistent with the rutile form of the oxide. Both experimental data and theoretical calculations show the close resemblance to results on single crystal TiO{sub 2}. Furthermore, the modeling studies reveal that the optical transitions near the bandedge arise from the bulk band structure. The photoelectrochemical properties of anodic TiO{sub 2} films have now been shown to obey the simple Gaertner-Butler model for the semiconductor-electrolyte interface, with a few modifications. The most important deviation has now been shown to be a result of multiple internal reflections in the oxide film.

  9. NANOSTRUCTURED METAL OXIDE CATALYSTS VIA BUILDING BLOCK SYNTHESES

    SciTech Connect (OSTI)

    Craig E. Barnes

    2013-03-05T23:59:59.000Z

    A broadly applicable methodology has been developed to prepare new single site catalysts on silica supports. This methodology requires of three critical components: a rigid building block that will be the main structural and compositional component of the support matrix; a family of linking reagents that will be used to insert active metals into the matrix as well as cross link building blocks into a three dimensional matrix; and a clean coupling reaction that will connect building blocks and linking agents together in a controlled fashion. The final piece of conceptual strategy at the center of this methodology involves dosing the building block with known amounts of linking agents so that the targeted connectivity of a linking center to surrounding building blocks is obtained. Achieving targeted connectivities around catalytically active metals in these building block matrices is a critical element of the strategy by which single site catalysts are obtained. This methodology has been demonstrated with a model system involving only silicon and then with two metal-containing systems (titanium and vanadium). The effect that connectivity has on the reactivity of atomically dispersed titanium sites in silica building block matrices has been investigated in the selective oxidation of phenols to benezoquinones. 2-connected titanium sites are found to be five times as active (i.e. initial turnover frequencies) than 4-connected titanium sites (i.e. framework titanium sites).

  10. The carburization of transition metal molybdates (MxMoO?, M= Cu, Ni or Co) and the generation of highly active metal/carbide catalysts for CO? hydrogenation

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

    Rodriguez, Jose A.; Xu, Wenqian; Ramirez, Pedro J.; Stachiola, Dario; Brito, Joaquin L.

    2015-05-06T23:59:59.000Z

    A new approach has been tested for the preparation of metal/Mo?C catalysts using mixed-metal oxide molybdates as precursors. Synchrotron-based in situ time-resolved X-ray diffraction was used to study the reduction and carburization processes of Cu?(MoO?)?(OH)?, a-NiMoO? and CoMoO?•nH?O by thermal treatment under mixtures of hydrogen and methane. In all cases, the final product was ?-Mo?C and a metal phase (Cu, Ni, or Co), but the transition sequence varied with the different metals, and it could be related to the reduction potential of the Cu²?, Ni²? and Co²? cations inside each molybdate. The synthesized Cu/Mo?C, Ni/Mo?C and Co/Mo?C catalysts were highlymore »active for the hydrogenation of CO?. The metal/Mo?C systems exhibited large variations in the selectivity towards methanol, methane and CnH?n?? (n > 2) hydrocarbons depending on the nature of the supported metal and its ability to cleave C-O bonds. Cu/Mo?C displayed a high selectivity for CO and methanol production. Ni/Mo?C and Co/Mo?C were the most active catalysts for the activation and full decomposition of CO?, showing high selectivity for the production of methane (Ni case) and CnH?n?? (n > 2) hydrocarbons (Co case).« less

  11. The carburization of transition metal molybdates (MxMoO?, M= Cu, Ni or Co) and the generation of highly active metal/carbide catalysts for CO? hydrogenation

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

    Rodriguez, Jose A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Xu, Wenqian [Brookhaven National Lab. (BNL), Upton, NY (United States); Ramirez, Pedro J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Univ. Central De Venezuela, Caracas (Venesuela); Stachiola, Dario [Brookhaven National Lab. (BNL), Upton, NY (United States); Brito, Joaquin L. [Inst. Venezolano de Investigaciones Cientificas, Caracas (Venezuela)

    2015-05-06T23:59:59.000Z

    A new approach has been tested for the preparation of metal/Mo?C catalysts using mixed-metal oxide molybdates as precursors. Synchrotron-based in situ time-resolved X-ray diffraction was used to study the reduction and carburization processes of Cu?(MoO?)?(OH)?, a-NiMoO? and CoMoO?•nH?O by thermal treatment under mixtures of hydrogen and methane. In all cases, the final product was ?-Mo?C and a metal phase (Cu, Ni, or Co), but the transition sequence varied with the different metals, and it could be related to the reduction potential of the Cu²?, Ni²? and Co²? cations inside each molybdate. The synthesized Cu/Mo?C, Ni/Mo?C and Co/Mo?C catalysts were highly active for the hydrogenation of CO?. The metal/Mo?C systems exhibited large variations in the selectivity towards methanol, methane and CnH?n?? (n > 2) hydrocarbons depending on the nature of the supported metal and its ability to cleave C-O bonds. Cu/Mo?C displayed a high selectivity for CO and methanol production. Ni/Mo?C and Co/Mo?C were the most active catalysts for the activation and full decomposition of CO?, showing high selectivity for the production of methane (Ni case) and CnH?n?? (n > 2) hydrocarbons (Co case).

  12. Stabilization of Electrocatalytic Metal Nanoparticles at Metal...

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

    Electrocatalytic Metal Nanoparticles at Metal-Metal Oxide-Graphene Triple Junction Points. Stabilization of Electrocatalytic Metal Nanoparticles at Metal-Metal Oxide-Graphene...

  13. Linker-Induced Anomalous Emission of Organic-Molecule Conjugated Metal-Oxide Nanoparticles

    SciTech Connect (OSTI)

    Turkowski, Volodymyr; Babu, Suresh; Le, Duy; Kumar, Amit; Haldar, Manas K.; Wagh, Anil V.; Hu, Zhongjian; Karakoti, Ajay S.; Gesquiere, Andre J.; Law, Benedict; Mallik, Sanku; Rahman, Talat S.; Leuenberger, Michael N.; Seal, Sudipta

    2012-06-26T23:59:59.000Z

    Semiconductor nanoparticles conjugated with organic- and dye-molecules to yield high efficiency visible photoluminescence (PL) hold great potential for many future technological applications. We show that folic acid (FA)-conjugated to nanosize TiO2 and CeO2 particles demonstrates a dramatic increase of photoemission intensity at wavelengths between 500 and 700 nm when derivatized using aminopropyl trimethoxysilane (APTMS) as spacer-linker molecules between the metal oxide and FA. Using density-functional theory (DFT) and time-dependent DFT calculations we demonstrate that the strong increase of the PL can be explained by electronic transitions between the titania surface oxygen vacancy (OV) states and the low-energy excited states of the FA/APTMS molecule anchored onto the surface oxygen bridge sites in close proximity to the OVs. We suggest this scenario to be a universal feature for a wide class of metal oxide nanoparticles, including nanoceria, possessing a similar band gap (3 eV) and with a large surface-vacancy-related density of electronic states. We demonstrate that the molecule-nanoparticle linker can play a crucial role in tuning the electronic and optical properties of nanosystems by bringing optically active parts of the molecule and of the surface close to each other.

  14. Vehicle Technologies Office Merit Review 2015: Metal Oxide Nano-Array Catalysts for Low Temperature Diesel Oxidation

    Broader source: Energy.gov [DOE]

    Presentation given by U. Conn at 2015 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about metal oxide nano-array catalysts for...

  15. Magnetic ground state of semiconducting transition metal trichalcogenide monolayers

    SciTech Connect (OSTI)

    Sivadas, Mr. Nikhil [Carnegie Mellon University (CMU); Daniels, Matthew W. [Carnegie Mellon University (CMU); Swendsen, Robert H. [Carnegie Mellon University (CMU); Okamoto, Satoshi [ORNL; Xiao, Di [Carnegie Mellon University (CMU)

    2015-01-01T23:59:59.000Z

    Layered transition-metal trichalcogenides with the chemical formula ABX3 have attracted recent interest as potential candidates for two-dimensional magnets. Using first-principles calculations within density functional theory, we investigate the magnetic ground states of monolayers of Mn- and Cr-based semiconducting trichalcogenides.We show that the second and third nearest-neighbor exchange interactions (J2 and J3) between magnetic ions, which have been largely overlooked in previous theoretical studies, are crucial in determining the magnetic ground state. Specifically, we find that monolayer CrSiTe3 is an antiferromagnet with a zigzag spin texture due to significant contribution from J3, whereas CrGeTe3 is a ferromagnet with a Curie temperature of 106 K. Monolayers of Mn compounds (MnPS3 and MnPSe3) always show antiferromagnetic N eel order. We identify the physical origin of various exchange interactions, and demonstrate that strain can be an effective knob for tuning the magnetic properties. Possible magnetic ordering in the bulk is also discussed. Our study suggests that ABX3 can be a promising platform to explore two-dimensional magnetic phenomena.

  16. Dislocations and Plasticity in bcc Transition Metals at High Pressure

    SciTech Connect (OSTI)

    Yang, L H; Tang, M; Moriarty, J A

    2009-01-23T23:59:59.000Z

    Using first-principles electronic structure calculations, quantum-based atomistic simulations and atomistically informed dislocation dynamics (DD) simulations, we have studied individual dislocation behavior and the multiscale modeling of single-crystal plasticity in the prototype bcc transition metals Ta, Mo and V under both ambient and high pressure conditions. The primary focus in this work is on the pressure-dependent structure, mobility and interaction of a/2<111> screw dislocations, which dominate the plastic deformation properties of these materials. At the electronic scale, first-principles calculations of elasticity, ideal strength and generalized stacking fault energy surfaces have been used to validate quantum-based multi-ion interatomic potentials. At the atomistic scale, these potentials have been used in flexible Green's function boundary condition simulations to study the core structure, Peierls stress {tau}{sub P}, thermally activated kink-pair formation and mobility below {tau}{sub P}, and phonon-drag mobility above {tau}{sub P}. These results have then been distilled into analytic velocity laws and used directly in predictive microscale DD simulations of flow stress and resolved yield stress over wide ranges of pressure, temperature and strain rate.

  17. Oxidation catalysts comprising metal exchanged hexaaluminate wherein the metal is Sr, Pd, La, and/or Mn

    DOE Patents [OSTI]

    Wickham, David (Boulder, CO); Cook, Ronald (Lakewood, CO)

    2008-10-28T23:59:59.000Z

    The present invention provides metal-exchanged hexaaluminate catalysts that exhibit good catalytic activity and/or stability at high temperatures for extended periods with retention of activity as combustion catalysts, and more generally as oxidation catalysts, that make them eminently suitable for use in methane combustion, particularly for use in natural gas fired gas turbines. The hexaaluminate catalysts of this invention are of particular interest for methane combustion processes for minimization of the generation of undesired levels (less than about 10 ppm) of NOx species. Metal exchanged hexaaluminate oxidation catalysts are also useful for oxidation of volatile organic compounds (VOC), particularly hydrocarbons. Metal exchanged hexaaluminate oxidation catalysts are further useful for partial oxidation, particularly at high temperatures, of reduced species, particularly hydrocarbons (alkanes and alkenes).

  18. Self assembled multi-layer nanocomposite of graphene and metal oxide materials

    SciTech Connect (OSTI)

    Liu, Jun; Choi, Daiwon; Kou, Rong; Nie, Zimin; Wang, Donghai; Yang, Zhenguo

    2014-09-16T23:59:59.000Z

    Nanocomposite materials having at least two layers, each layer consisting of one metal oxide bonded to at least one graphene layer were developed. The nanocomposite materials will typically have many alternating layers of metal oxides and graphene layers, bonded in a sandwich type construction and will be incorporated into an electrochemical or energy storage device.

  19. Self assembled multi-layer nanocomposite of graphene and metal oxide materials

    DOE Patents [OSTI]

    Liu, Jun; Aksay, Ilhan A; Choi, Daiwon; Kou, Rong; Nie, Zimin; Wang, Donghai; Yang, Zhenguo

    2013-10-22T23:59:59.000Z

    Nanocomposite materials having at least two layers, each layer consisting of one metal oxide bonded to at least one graphene layer were developed. The nanocomposite materials will typically have many alternating layers of metal oxides and graphene layers, bonded in a sandwich type construction and will be incorporated into an electrochemical or energy storage device.

  20. Method of dissolving metal oxides with di- or polyphosphonic acid and a redundant

    DOE Patents [OSTI]

    Horwitz, Earl P. (Argonne, IL); Chiarizia, Renato (Argonne, IL)

    1996-01-01T23:59:59.000Z

    A method of dissolving metal oxides using a mixture of a di- or polyphosphonic acid and a reductant wherein each is present in a sufficient amount to provide a synergistic effect with respect to the dissolution of metal oxides and optionally containing corrosion inhibitors and pH adjusting agents.

  1. Microalloying of transition metal silicides by mechanical activation and field-activated reaction

    DOE Patents [OSTI]

    Munir, Zuhair A. (Davis, CA); Woolman, Joseph N. (Davis, CA); Petrovic, John J. (Los Alamos, NM)

    2003-09-02T23:59:59.000Z

    Alloys of transition metal suicides that contain one or more alloying elements are fabricated by a two-stage process involving mechanical activation as the first stage and densification and field-activated reaction as the second stage. Mechanical activation, preferably performed by high-energy planetary milling, results in the incorporation of atoms of the alloying element(s) into the crystal lattice of the transition metal, while the densification and field-activated reaction, preferably performed by spark plasma sintering, result in the formation of the alloyed transition metal silicide. Among the many advantages of the process are its ability to accommodate materials that are incompatible in other alloying methods.

  2. Phase transition into the metallic state in hypothetical (without molecules) dense atomic hydrogen

    SciTech Connect (OSTI)

    Khomkin, A. L., E-mail: alhomkin@mail.ru; Shumikhin, A. S. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)] [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

    2013-10-15T23:59:59.000Z

    A simple physical model of the metal-dielectric (vapor-liquid) phase transition in hypothetical (without molecules) atomic hydrogen is proposed. The reason for such a transition is the quantum collective cohesive energy occurring due to quantum electron-electron exchange similar to the cohesive energy in the liquid-metal phase of alkali metals. It is found that the critical parameters of the transition are P{sub c} ? 41000 atm, ?{sub c} ? 0.1 g/cm{sup 3}, and T{sub c} ? 9750 K.

  3. Surface phases and their influence on metal-oxide interfaces. Progress report

    SciTech Connect (OSTI)

    Blakely, J.

    1993-01-01T23:59:59.000Z

    This project is concerned with adsorbed monolayers on metal surfaces and their effects on oxidation kinetics and metal-oxide adhesion; proposed work is a study of metallurgy of 2-dimensional systems with emphasis on binary adsorbed layers. Experimental techniques which can be used include electron diffraction, atomic force and tunneling microscopy, environmental SEM, and secondary electron spectroscopies. Intention is to try to extract information on adsorbate interactions through comparison with model predictions; initially simple pair interaction potentials will be used. Atomic steps on single crystal surfaces, which affect nucleation/growth of overlayers, will be extended to metal oxide systems to form atomic step arrays as preferential sites for surface nucleation of oxides etc. Adsorbed (or segregated) monolayers at metal/oxide interfaces also affect adhesion and further oxidation. S and O adsorption on Ni and NiFe alloy surfaces were studied and are discussed.

  4. Models for transition metal oxides and for protein design

    E-Print Network [OSTI]

    Zhou, Fei, Ph. D. Massachusetts Institute of Technology

    2006-01-01T23:59:59.000Z

    A large number of properties of solid state materials can now be predicted with standard first-principles methods such as the Local Density (LDA) or Generalized Gradient Approximation (GGA). However, known problems exist ...

  5. Transition metal gettering studies and simulation for the optimization of silicon photovoltaic device processing

    E-Print Network [OSTI]

    Smith, Aimée Louise, 1971-

    2002-01-01T23:59:59.000Z

    We use what is known about transition metal (TM) defect thermodynamic driving forces and kinetic responses to make predictive simulation of gettering during solar cell fabrication possible. We have developed a simulator ...

  6. Measuring the Kernel TimeDependent Density Functional Theory with XRay Absorption Spectroscopy Transition Metals

    E-Print Network [OSTI]

    Gross, E.K.U.

    Transition Metals Scherz, Gross, Appel, Sorg, K. Baberschke, and Wende Fachbereich Physik, Freie Universita­Kohn approximation prob­ lem shown, new approximation suggested. But the value DFT constructing approxi­ mation

  7. Superelastic metal-insulator phase transition in single-crystal VO[subscript 2] nanobeams

    E-Print Network [OSTI]

    Fan, W.

    We investigated external-stress-induced metal-insulator phase transitions in cantilevered single-crystal VO[subscript 2] nanobeams at variable temperatures using a combined theoretical and experimental approach. An atomic ...

  8. Al-doped HfO2/In0.53Ga0.47As metal-oxide-semiconductor capaci

    E-Print Network [OSTI]

    Stemmer, Susanne

    2011-01-01T23:59:59.000Z

    MOS (Metal Oxide Semiconductor) Phys- ics and Technologywas funded by the Semiconductor Re- search Corporation0.47 As metal-oxide-semiconductor capacitors Yoontae Hwang,

  9. Enhanced visible-light absorption of mesoporous TiO2 by co-doping with transition-metal/nitrogen ions

    SciTech Connect (OSTI)

    Mathis, John [Embry-Riddle Aeronautical University; Bi, Zhonghe [ORNL; Bridges, Craig A [ORNL; Kidder, Michelle [ORNL; Paranthaman, Mariappan Parans [ORNL

    2013-01-01T23:59:59.000Z

    Titanium (IV) oxide, TiO2, has been the object of intense scrutiny for energy applications. TiO2 is inexpensive, non-toxic, and has excellent corrosion resistance when exposed to electrolytes. A major drawback preventing the widespread use TiO2 for photolysis is its relatively large band gap of ~3eV. Only light with wavelengths shorter than 400 nm, which is in the ultraviolet portion of the spectrum, has sufficient energy to be absorbed. Less than 14 percent of the solar irradiation reaching the earth s surface has energy exceeding this band gap. Adding dopants such as transition metals has long been used to reduce the gap and increase photocatalytic activity by accessing the visible part of the solar spectrum. The degree to which the band gap is reduced using transition metals depends in part on the overlap of the d-orbitals of the transition metals with the oxygen p-orbitals. Therefore, doping with anions such as nitrogen to modify the cation-anion orbital overlap is another approach to reduce the gap. Recent studies suggest that using a combination of transition metals and nitrogen as dopants is more effective at introducing intermediate states within the band gap, effectively narrowing it. Here we report the synthesis of mesoporous TiO2 spheres, co-doped with transition metals and nitrogen that exhibit a nearly flat absorbance response across the visible spectrum extending into the near infrared.

  10. Preparation of transition metal nanoparticles and surfaces modified with (CO) polymers synthesized by RAFT

    DOE Patents [OSTI]

    McCormick, III, Charles L. (Hattiesburg, MS); Lowe, Andrew B. (Hattiesburg, MS); Sumerlin, Brent S. (Pittsburgh, PA)

    2006-10-25T23:59:59.000Z

    A new, facile, general one-phase method of generating thiol-functionalized transition metal nanoparticles and surface modified by (co)polymers synthesized by the RAFT method is described. The method includes the steps of forming a (co)polymer in aqueous solution using the RAFT methodology, forming a collidal transition metal precursor solution from an appropriate transition metal; adding the metal precursor solution or surface to the (co)polymer solution, adding a reducing agent into the solution to reduce the metal colloid in situ to produce the stabilized nanoparticles or surface, and isolating the stabilized nanoparticles or surface in a manner such that aggregation is minimized. The functionalized surfaces generated using these methods can further undergo planar surface modifications, such as fuctionalization with a variety of different chemical groups, expanding their utility and application.

  11. Bridged transition-metal complexes and uses thereof for hydrogen separation, storage and hydrogenation

    DOE Patents [OSTI]

    Lilga, M.A.; Hallen, R.T.

    1990-08-28T23:59:59.000Z

    The present invention constitutes a class of organometallic complexes which reversibly react with hydrogen to form dihydrides and processes by which these compounds can be utilized. The class includes bimetallic complexes in which two cyclopentadienyl rings are bridged together and also separately [pi]-bonded to two transition metal atoms. The transition metals are believed to bond with the hydrogen in forming the dihydride. Transition metals such as Fe, Mn or Co may be employed in the complexes although Cr constitutes the preferred metal. A multiple number of ancillary ligands such as CO are bonded to the metal atoms in the complexes. Alkyl groups and the like may be substituted on the cyclopentadienyl rings. These organometallic compounds may be used in absorption/desorption systems and in facilitated transport membrane systems for storing and separating out H[sub 2] from mixed gas streams such as the producer gas from coal gasification processes. 3 figs.

  12. Preparation of transition metal nanoparticles and surfaces modified with (CO)polymers synthesized by RAFT

    DOE Patents [OSTI]

    McCormick, III., Charles L.; Lowe, Andrew B.; Sumerlin, Brent S.

    2006-11-21T23:59:59.000Z

    A new, facile, general one-phase method of generating thio-functionalized transition metal nanoparticles and surfaces modified by (co)polymers synthesized by the RAFT method is described. The method includes the stops of forming a (co)polymer in aqueous solution using the RAFT methodology, forming a colloidal transition metal precursor solution from an appropriate transition metal; adding the metal precursor solution or surface to the (co)polymer solution, adding a reducing agent into the solution to reduce the metal colloid in situ to produce the stabilized nanoparticles or surface, and isolating the stabilized nanoparticles or surface in a manner such that aggregation is minimized. The functionalized surfaces generated using these methods can further undergo planar surface modifications, such as functionalization with a variety of different chemical groups, expanding their utility and application.

  13. Preparation of transition metal nanoparticles and surfaces modified with (co)polymers synthesized by RAFT

    DOE Patents [OSTI]

    McCormick, III, Charles L. (Hattiesburg, MS); Lowe, Andrew B. (Hattiesburg, MS); Sumerlin, Brent S. (Pittsburgh, PA)

    2011-12-27T23:59:59.000Z

    A new, facile, general one-phase method of generating thiol-functionalized transition metal nanoparticles and surfaces modified by (co)polymers synthesized by the RAFT method is described. The method includes the steps of forming a (co)polymer in aqueous solution using the RAFT methodology, forming a colloidal transition metal precursor solution from an appropriate transition metal; adding the metal precursor solution or surface to the (co)polymer solution, adding a reducing agent into the solution to reduce the metal colloid in situ to produce the stabilized nanoparticles or surface, and isolating the stabilized nanoparticles or surface in a manner such that aggregation is minimized. The functionalized surfaces generated using these methods can further undergo planar surface modifications, such as functionalization with a variety of different chemical groups, expanding their utility and application.

  14. Bridged transition-metal complexes and uses thereof for hydrogen separation, storage and hydrogenation

    DOE Patents [OSTI]

    Lilga, Michael A. (Richland, WA); Hallen, Richard T. (Richland, WA)

    1991-01-01T23:59:59.000Z

    The present invention constitutes a class of organometallic complexes which reversibly react with hydrogen to form dihydrides and processes by which these compounds can be utilized. The class includes bimetallic complexes in which two cyclopentadienyl rings are bridged together and also separately .pi.-bonded to two transition metal atoms. The transition metals are believed to bond with the hydrogen in forming the dihydride. Transition metals such as Fe, Mn or Co may be employed in the complexes although Cr constitutes the preferred metal. A multiple number of ancilliary ligands such as CO are bonded to the metal atoms in the complexes. Alkyl groups and the like may be substituted on the cyclopentadienyl rings. These organometallic compounds may be used in absorption/desorption systems and in facilitated transport membrane systems for storing and separating out H.sub.2 from mixed gas streams such as the product gas from coal gasification processes.

  15. Bridged transition-metal complexes and uses thereof for hydrogen separation, storage and hydrogenation

    DOE Patents [OSTI]

    Lilga, M.A.; Hallen, R.T.

    1991-10-15T23:59:59.000Z

    The present invention constitutes a class of organometallic complexes which reversibly react with hydrogen to form dihydrides and processes by which these compounds can be utilized. The class includes bimetallic complexes in which two cyclopentadienyl rings are bridged together and also separately [pi]-bonded to two transition metal atoms. The transition metals are believed to bond with the hydrogen in forming the dihydride. Transition metals such as Fe, Mn or Co may be employed in the complexes although Cr constitutes the preferred metal. A multiple number of ancillary ligands such as CO are bonded to the metal atoms in the complexes. Alkyl groups and the like may be substituted on the cyclopentadienyl rings. These organometallic compounds may be used in absorption/desorption systems and in facilitated transport membrane systems for storing and separating out H[sub 2] from mixed gas streams such as the product gas from coal gasification processes. 3 figures.

  16. Bridged transition-metal complexes and uses thereof for hydrogen separation, storage and hydrogenation

    DOE Patents [OSTI]

    Lilga, Michael A. (Richland, WA); Hallen, Richard T. (Richland, WA)

    1990-01-01T23:59:59.000Z

    The present invention constitutes a class of organometallic complexes which reversibly react with hydrogen to form dihydrides and processes by which these compounds can be utilized. The class includes bimetallic complexes in which two cyclopentadienyl rings are bridged together and also separately .pi.-bonded to two transition metal atoms. The transition metals are believed to bond with the hydrogen in forming the dihydride. Transition metals such as Fe, Mn or Co may be employed in the complexes although Cr constitutes the preferred metal. A multiple number of ancilliary ligands such as CO are bonded to the metal atoms in the complexes. Alkyl groups and the like may be substituted on the cyclopentadienyl rings. These organometallic compounds may be used in absorption/desorption systems and in facilitated transport membrane systems for storing and separating out H.sub.2 from mixed gas streams such as the produce gas from coal gasification processes.

  17. An ultrahigh vacuum facility for the co-deposition of amorphous transition metal alloy thin films

    E-Print Network [OSTI]

    Nicoli, Victor Michael

    1984-01-01T23:59:59.000Z

    AN ULTRAHIGH VACUUM FACILITY FOR THE CO-DEPOSITION OF AMORPHOUS TRANSITION METAL ALLOY THIN FILMS A Thesis by VICTOR MICHAEL NICOLI Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE May 1984 Major Subject: Physics AN ULTRAHIGH VACUUM FACILITY FOR THE CO-DEPOSITION OF AMORPHOUS TRANSITION METAL ALLOY THIN FILMS A Thes1s by VICTOR MICHAEL NICOLI Approved as to style and content by: ona . aug (Cha...

  18. Regenerable MgO promoted metal oxide oxygen carriers for chemical looping combustion

    DOE Patents [OSTI]

    Siriwardane, Ranjani V.; Miller, Duane D.

    2014-08-19T23:59:59.000Z

    The disclosure provides an oxygen carrier comprised of a plurality of metal oxide particles in contact with a plurality of MgO promoter particles. The MgO promoter particles increase the reaction rate and oxygen utilization of the metal oxide when contacting with a gaseous hydrocarbon at a temperature greater than about 725.degree. C. The promoted oxide solid is generally comprised of less than about 25 wt. % MgO, and may be prepared by physical mixing, incipient wetness impregnation, or other methods known in the art. The oxygen carrier exhibits a crystalline structure of the metal oxide and a crystalline structure of MgO under XRD crystallography, and retains these crystalline structures over subsequent redox cycles. In an embodiment, the metal oxide is Fe.sub.2O.sub.3, and the gaseous hydrocarbon is comprised of methane.

  19. Correlation between oxygen adsorption energy and electronic structure of transition metal macrocyclic complexes

    SciTech Connect (OSTI)

    Liu, Kexi; Lei, Yinkai; Wang, Guofeng, E-mail: guw8@pitt.edu [Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15261 (United States)] [Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15261 (United States)

    2013-11-28T23:59:59.000Z

    Oxygen adsorption energy is directly relevant to the catalytic activity of electrocatalysts for oxygen reduction reaction (ORR). In this study, we established the correlation between the O{sub 2} adsorption energy and the electronic structure of transition metal macrocyclic complexes which exhibit activity for ORR. To this end, we have predicted the molecular and electronic structures of a series of transition metal macrocyclic complexes with planar N{sub 4} chelation, as well as the molecular and electronic structures for the O{sub 2} adsorption on these macrocyclic molecules, using the density functional theory calculation method. We found that the calculated adsorption energy of O{sub 2} on the transition metal macrocyclic complexes was linearly related to the average position (relative to the lowest unoccupied molecular orbital of the macrocyclic complexes) of the non-bonding d orbitals (d{sub z{sup 2}}, d{sub xy}, d{sub xz}, and d{sub yz}) which belong to the central transition metal atom. Importantly, our results suggest that varying the energy level of the non-bonding d orbitals through changing the central transition metal atom and/or peripheral ligand groups could be an effective way to tuning their O{sub 2} adsorption energy for enhancing the ORR activity of transition metal macrocyclic complex catalysts.

  20. Electronically conductive ceramics for high temperature oxidizing environments

    DOE Patents [OSTI]

    Kucera, G.H.; Smith, J.L.; Sim, J.W.

    1983-11-10T23:59:59.000Z

    This invention pertains to a high temperature, ceramic composition having electronic conductivity as measured by resistivity below about 500 ohm-cm, chemical stability particularly with respect to cathode conditions in a molten carbonate fuel cell, and composed of an alkali metal, transition metal oxide containing a dopant metal in the crystalline structure to replace a portion of the alkali metal or transition metal.

  1. Epitaxial Growth and Properties of Doped Transition Metal and...

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

    of crystalline oxide film growth using vacuum methods is reviewed and discussed with an eye toward gaining fundamental insights into the relationships between growth process and...

  2. Strong Bond Activation with Late Transition-Metal Pincer Complexes as a Foundation for Potential Catalysis

    E-Print Network [OSTI]

    Zhu, Yanjun

    2012-07-16T23:59:59.000Z

    introduction for pincer ligands ................................................ 1 1.2 Synthesis of pincer ligated transition metal complexes ........................ 3 1.3 Structural preference for group 9/10 metal complexes (4d and 5d) ...... 9 1... ..................................................................................... 126 V SYNTHESIS, CHARACTERIZATION, AND REACTIVITY OF A RHODIUM DIFLUOROCARBENE COMPLEX SUPPORTED BY PNP PINCER LIGAND ........................................................................................ 144 5.1 Introduction...

  3. Toward Photochemical Water Splitting Using Band-Gap-Narrowed Semiconductors and Transition-Metal Based Molecular Catalysts

    SciTech Connect (OSTI)

    Muckerman,J.T.; Rodriguez, J.A.; Fujita, E.

    2009-06-07T23:59:59.000Z

    We are carrying out coordinated theoretical and experimental studies of toward photochemical water splitting using band-gap-narrowed semiconductors (BGNSCs) with attached multi-electron molecular water oxidation and hydrogen production catalysts. We focus on the coupling between the materials properties and the H{sub 2}O redox chemistry, with an emphasis on attaining a fundamental understanding of the individual elementary steps in the following four processes: (1) Light-harvesting and charge-separation of stable oxide or oxide-derived semiconductors for solar-driven water splitting, including the discovery and characterization of the behavior of such materials at the aqueous interface; (2) The catalysis of the four-electron water oxidation by dinuclear hydroxo transition-metal complexes with quinonoid ligands, and the rational search for improved catalysts; (3) Transfer of the design principles learned from the elucidation of the DuBois-type hydrogenase model catalysts in acetonitrile to the rational design of two-electron hydrogen production catalysts for aqueous solution; (4) Combining these three elements to examine the function of oxidation catalysts on BGNSC photoanode surfaces and hydrogen production catalysts on cathode surfaces at the aqueous interface to understand the challenges to the efficient coupling of the materials functions.

  4. Reaction of bisarenyl, cyclopentadienyl, and carbonyl transition metal compounds with polyhydric alcohols

    SciTech Connect (OSTI)

    Slushkov, A.M.; Petrov, B.I.; Domrachev, G.A.

    1987-08-20T23:59:59.000Z

    It is shown that the thermally stable (to 300-400/sup 0/C) transition metal glycolates, glycerates, and pinacolates could be obtained from bisarenyl, cyclopentadienyl, and carbonyl metal compounds by reaction with polymeric alcohols. At 150-180/sup 0/C monomeric compounds are formed; these are converted to polymeric products above 200/sup 0/C. When two glycolates react with various metals or when glycolates react with organometallic compounds, new, mixed complexes of a polymeric nature are obtained.

  5. Reversible mechanism for spin crossover in transition-metal cyanides

    E-Print Network [OSTI]

    Kabir, Mohammad Mukul

    We report the mechanisms for reversible and repeatable spin transition in a Prussian blue analog crystal, KCo[Fe(CN)[subscript 6

  6. Production of crystalline refractory metal oxides containing colloidal metal precipitates and useful as solar-effective absorbers

    DOE Patents [OSTI]

    Narayan, Jagdish (Knoxville, TN); Chen, Yok (Oak Ridge, TN)

    1983-01-01T23:59:59.000Z

    This invention is a new process for producing refractory crystalline oxides having improved or unusual properties. The process comprises the steps of forming a doped-metal crystal of the oxide; exposing the doped crystal in a bomb to a reducing atmosphere at superatmospheric pressure and a temperature effecting precipitation of the dopant metal in the crystal lattice of the oxide but insufficient to effect net diffusion of the metal out of the lattice; and then cooling the crystal. Preferably, the cooling step is effected by quenching. The process forms colloidal precipitates of the metal in the oxide lattice. The process may be used, for example, to produce thermally stable black MgO crystalline bodies containing magnetic colloidal precipitates consisting of about 99% Ni. The Ni-containing bodies are solar-selective absorbers, having a room-temperature absorptivity of about 0.96 over virtually all of the solar-energy spectrum and exhibiting an absorption edge in the region of 2 .mu.m. The process parameters can be varied to control the average size of the precipitates. The process can produce a black MgO crystalline body containing colloidal Ni precipitates, some of which have the face-centered-cubic structure and others of which have the body-centered cubic structure. The products of the process are metal-precipitate-containing refractory crystalline oxides which have improved or unique optical, mechanical, magnetic, and/or electronic properties.

  7. Characterization of a Fe/Y{sub 2}O{sub 3} metal/oxide interface using neutron and x-ray scattering

    SciTech Connect (OSTI)

    Watkins, E. B.; Majewski, J., E-mail: demkowicz@mit.edu, E-mail: jarek@lanl.gov [Lujan Neutron Scattering Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Kashinath, A. [Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Computational Modeling Technology, Aramco Research Center—Boston, Cambridge, Massachusetts 02139 (United States); Wang, P. [Lujan Neutron Scattering Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Intel Corporation, Hillsboro, Oregon, 97006 (United States); Baldwin, J. K. [Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Demkowicz, M. J., E-mail: demkowicz@mit.edu, E-mail: jarek@lanl.gov [Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2014-07-28T23:59:59.000Z

    The structure of metal/oxide interfaces is important to the radiation resistance of oxide dispersion-strengthened steels. We find evidence of gradual variations in stoichiometry and magnetization across a Fe/Y{sub 2}O{sub 3} metal/oxide heterophase interface using neutron and x-ray reflectometry. These findings suggest that the Fe/Y{sub 2}O{sub 3} interface is a transitional zone approximately ?64?Å-thick containing mixtures or compounds of Fe, Y, and O. Our results illustrate the complex chemical and magnetic nature of Fe/oxide interfaces and demonstrate the utility of combined neutron and x-ray techniques as tools for characterizing them.

  8. Method for the rapid synthesis of large quantities of metal oxide nanowires at low temperatures

    DOE Patents [OSTI]

    Sunkara, Mahendra Kumar (Louisville, KY); Vaddiraju, Sreeram (Mountain View, CA); Mozetic, Miran (Ljubljan, SI); Cvelbar, Uros (Idrija, SI)

    2009-09-22T23:59:59.000Z

    A process for the rapid synthesis of metal oxide nanoparticles at low temperatures and methods which facilitate the fabrication of long metal oxide nanowires. The method is based on treatment of metals with oxygen plasma. Using oxygen plasma at low temperatures allows for rapid growth unlike other synthesis methods where nanomaterials take a long time to grow. Density of neutral oxygen atoms in plasma is a controlling factor for the yield of nanowires. The oxygen atom density window differs for different materials. By selecting the optimal oxygen atom density for various materials the yield can be maximized for nanowire synthesis of the metal.

  9. Electronic Structure and Properties of Transition Metal-Benzene Ravindra Pandey, Bijan K. Rao,*, Purusottam Jena, and Miguel Alvarez Blanco

    E-Print Network [OSTI]

    Pandey, Ravi

    Electronic Structure and Properties of Transition Metal-Benzene Complexes Ravindra Pandey, Bijan Kd transition metal atoms (M) interacting with benzene molecules (Bz) is carried out using density. The variation of the metal-benzene distances, dissociation energies, ionization potentials, electron affinities

  10. Kinetics of local probe oxidation of ultrathin V, Nb, Ta, Ti, TiN, and W metal films

    SciTech Connect (OSTI)

    Sagunova, I. V., E-mail: pcfme@miee.ru; Shevyakov, V. I.; Gavrilov, S. A.; Belov, A. N. [Moscow Institute of Electronic Technology (Technical University) (Russian Federation)

    2010-12-15T23:59:59.000Z

    The specific features of the kinetics of local probe oxidation of ultrathin V, Nb, Ta, Ti, TiN, and W metal films are studied. It is established that the kinetics of the oxidation process depends on such properties of the material to be oxidized as the resistivity, the presence of a natural surface oxide film and its thickness, the relationship between the densities of the metal and oxide, and the electrochemical constant of the oxidation process. For the material that provides a high efficiency of formation of local insulator nanoregions, vanadium is chosen, since this metal exhibits the maximum rate of anodic probe oxidation.

  11. active complementary metal-oxide-semiconductor: Topics by E-print...

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

    Metal Oxide Semiconductor (CMOS) tech- Corresponding author. Email address: antonio 465 Tycho Brahe CCD CMOS Physics Websites Summary: 12;12;12;117 Tycho Brahe 20 19 70 CCD...

  12. Thermal and Physical Properties of Plutonium Dioxide Produced from the Oxidation of Metal: a Data Summary

    SciTech Connect (OSTI)

    Wayne, David M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-01-13T23:59:59.000Z

    The ARIES Program at the Los Alamos National Laboratory removes plutonium metal from decommissioned nuclear weapons, and converts it to plutonium dioxide in a specially-designed Direct Metal Oxidation furnace. The plutonium dioxide is analyzed for specific surface area, particle size distribution, and moisture content. The purpose of these analyses is to certify that the plutonium dioxide powder meets or exceeds the specifications of the end-user, and the specifications for the packaging and transport of nuclear materials. Analytical results from plutonium dioxide from ARIES development activities, from ARIES production activities, from muffle furnace oxidation of metal, and from metal that was oxidized over a lengthy time interval in air at room temperature, are presented. The processes studied produce plutonium dioxide powder with distinct differences in measured properties, indicating the significant influence of oxidation conditions on physical properties.

  13. Near-infrared photodetector consisting of J-aggregating cyanine dye and metal oxide thin films

    E-Print Network [OSTI]

    Osedach, Timothy P.

    We demonstrate a near-infrared photodetector that consists of a thin film of the J-aggregating cyanine dye, U3, and transparent metal-oxide charge transport layers. The high absorption coefficient of the U3 film, combined ...

  14. Metal-insulator transition in Na{sub x}WO{sub 3}: Photoemission spectromicroscopy study

    SciTech Connect (OSTI)

    Paul, Sanhita, E-mail: raj@iiserkol.ac.in; Ghosh, Anirudha, E-mail: raj@iiserkol.ac.in; Raj, Satyabrata, E-mail: raj@iiserkol.ac.in [Department of Physical Sciences, Indian Institute of Science Education and Research - Kolkata, Mohanpur Campus, Nadia -741252, West Bengal (India)

    2014-04-24T23:59:59.000Z

    We have investigated the validity of percolation model, which is quite often invoked to explain the metal-insulator transition in sodium tungsten bronzes, Na{sub x}WO{sub 3} by photoelectron spectromicroscopy. The spatially resolved direct spectromicroscopic probing on both the insulating and metallic phases of high quality single crystals of Na{sub x}WO{sub 3} reveals the absence of any microscopic inhomogeneities embedded in the system within the experimental limit. Neither any metallic domains in the insulating host nor any insulating domains in the metallic host have been found to support the validity of percolation model to explain the metal-insulator transition in Na{sub x}WO{sub 3}.

  15. Structure and magnetism of transition-metal implanted dilute magnetic semiconductors

    E-Print Network [OSTI]

    Pereira, Lino; Temst, K; Araújo, JP; Wahl, U

    The discovery of a dilute magnetic semiconductor (DMS) in which ferromagnetism is carrier-mediated and persists above room temperature is a critical step towards the development of semiconductor-based spintronics. Among the many types of DMS materials which have been investigated, the current research interest can be narrowed down to two main classes of materials: (1) narrow-gap III-V semiconductors, mostly GaAs and InAs, doped with Mn; (2) wide-gap oxides and nitrides doped with 3d transition metals, mostly Mn- and Co-doped ZnO and Mn-doped GaN. With a number of interesting functionalities deriving from the carrier-mediated ferromagnetism and demonstrated in various proof-of-concept devices, Mn-doped GaAs has become, among DMS materials, one of the best candidates for technological application. However, despite major developments over the last 15 years, the maximum Curie temperature (185 K) remains well below room temperature. On the other hand, wide-gap DMS materials appear to exhibit ferromagnetic behavior...

  16. Cyclopentadienyl-containing low-valent early transition metal olefin polymerization catalysts

    DOE Patents [OSTI]

    Marks, Tobin J.; Luo, Lubin; Yoon, Sung Cheol

    2007-01-09T23:59:59.000Z

    A catalyst system useful to polymerize and co-polymerize polar and non-polar olefin monomers is formed by in situ reduction with a reducing agent of a catalyst precursor comprising {Cp*MRR'.sub.n}.sup.+{A}.sup.- wherein Cp* is a cyclopentadienyl or substituted cyclopentadienyl moiety; M is an early transition metal; R is a C.sub.1 C.sub.20 hydrocarbyl; R' are independently selected from hydride, C.sub.1 C.sub.20 hydrocarbyl, SiR''.sub.3, NR''.sub.2, OR'', SR'', GeR''.sub.3, SnR''.sub.3, and C.dbd.C-containing groups (R''=C.sub.1 C.sub.10 hydrocarbyl); n is an integer selected to balance the oxidation state of M; and A is a suitable non-coordinating anionic cocatalyst or precursor. This catalyst system may form stereoregular olefin polymers including syndiotactic polymers of styrene and methylmethacrylate and isotactic copolymers of polar and nonpolar olefin monomers such as methylmethacrylate and styrene.

  17. Cyclopentadienyl-containing low-valent early transition metal olefin polymerization catalysts

    DOE Patents [OSTI]

    Marks, Tobin J.; Luo, Lubin; Yoon, Sung Cheol

    2006-10-10T23:59:59.000Z

    A catalyst system useful to polymerize and co-polymerize polar and non-polar olefin monomers is formed by in situ reduction with a reducing agent of a catalyst precursor comprising {Cp*MRR'.sub.n}.sup.+{A}.sup.- wherein Cp* is a cyclopentadienyl or substituted cyclopentadienyl moiety; M is an early transition metal; R is a C.sub.1 C.sub.20 hydrocarbyl; R' are independently selected from hydride, C.sub.1 C.sub.20 hydrocarbyl, SiR''.sub.3, NR''.sub.2, OR'', SR'', GeR''.sub.3, SnR''.sub.3, and C.dbd.C-containing groups (R''=C.sub.1 C.sub.10 hydrocarbyl); n is an integer selected to balance the oxidation state of M; and A is a suitable non-coordinating anionic cocatalyst or precursor. This catalyst system may form stereoregular olefin polymers including syndiotactic polymers of styrene and methylmethacrylate and isotactic copolymers of polar and nonpolar olefin monomers such as methylmethacrylate and styrene.

  18. Neutral bimetallic transition metal phenoxyiminato catalysts and related polymerization methods

    DOE Patents [OSTI]

    Marks, Tobin J. (Evanston, IL); Rodriguez, Brandon A. (Evanston, IL); Delferro, Massimiliano (Chicago, IL)

    2012-08-07T23:59:59.000Z

    A catalyst composition comprising a neutral bimetallic diphenoxydiiminate complex of group 10 metals or Ni, Pd or Pt is disclosed. The compositions can be used for the preparation of homo- and co-polymers of olefinic monomer compounds.

  19. Transition metals on the (0001) surface of graphite: Fundamental aspects of adsorption, diffusion, and morphology

    SciTech Connect (OSTI)

    Appy, David [Ames Laboratory; Lei, Huaping [Ames Laboratory; Wang, Cai-Zhuang [Ames Laboratory; Tringides, Michael C [Ames Laboratory; Liu, Da-Jiang [Ames Laboratory; Evans, James W [Ames Laboratory; Thiel, Patricia A [Ames Laboratory

    2014-08-01T23:59:59.000Z

    In this article, we review basic information about the interaction of transition metal atoms with the (0 0 0 1) surface of graphite, especially fundamental phenomena related to growth. Those phenomena involve adatom-surface bonding, diffusion, morphology of metal clusters, interactions with steps and sputter-induced defects, condensation, and desorption. General traits emerge which have not been summarized previously. Some of these features are rather surprising when compared with metal-on-metal adsorption and growth. Opportunities for future work are pointed out.

  20. Synthesis of high T.sub.C superconducting coatings and patterns by melt writing and oxidation of metallic precursor alloys

    DOE Patents [OSTI]

    Gao, Wei (Somerville, MA); Vander Sande, John B. (Newbury, MA)

    1998-01-01T23:59:59.000Z

    A method is provided for fabrication of superconducting oxides and superconducting oxide composites and for joining superconductors to other materials. A coating of a molten alloy containing the metallic elements of the oxide is applied to a substrate surface and oxidized to form the superconducting oxide. A material can be contacted to the molten alloy which is subsequently oxidized joining the material to the resulting superconducting oxide coating. Substrates of varied composition and shape can be coated or joined by this method.

  1. Surfactant Organic Molecules Restore Magnetism in Metal-Oxide Nanoparticle Surfaces

    E-Print Network [OSTI]

    Pennycook, Steve

    acid and the nanoparticles would prevent further oxidation to Fe2O3, which could be detrimental functional calculations, we establish the key role of the nonmagnetic organic acid cappiSurfactant Organic Molecules Restore Magnetism in Metal-Oxide Nanoparticle Surfaces Juan Salafranca

  2. ERDC/ELTR-11-9 Evaluation of Metals Release from Oxidation

    E-Print Network [OSTI]

    US Army Corps of Engineers

    ERDC/ELTR-11-9 Evaluation of Metals Release from Oxidation of Fly Ash during Dredging of the Emory Oxidation of Fly Ash during Dredging of the Emory River, TN Jeffery A. Steevens, Anthony J. Bednar, Mark A 22, 2008 and the subsequent dredging operations to remove the fly ash from the Emory River. Fly ash

  3. Analytica Chimica Acta 573574 (2006) 913 Metal oxide thin films as sensing layers for ozone detection

    E-Print Network [OSTI]

    2006-01-01T23:59:59.000Z

    Analytica Chimica Acta 573­574 (2006) 9­13 Metal oxide thin films as sensing layers for ozone. Their structural, electrical and ozone sensing properties were analyzed. Structural investigations carried out with ultraviolet light and subsequent oxidation in ozone atmosphere at room temperature. © 2006 Elsevier B.V. All

  4. A general holographic metal/superconductor phase transition model

    E-Print Network [OSTI]

    Yan Peng; Yunqi Liu

    2014-10-27T23:59:59.000Z

    We study the scalar condensation of a general holographic superconductor model in AdS black hole background away from the probe limit. We find the model parameters together with the scalar mass and backreaction can determine the order of phase transitions completely. In addition, we observe two types of discontinuities of the scalar operator in the case of first order phase transitions. We analyze in detail the effects of the scalar mass and backreaction on the formation of discontinuities and arrive at an approximate relation between the threshold model parameters. Furthermore, we obtain superconductor solutions corresponding to higher energy states and examine the stability of these superconductor solutions.

  5. A general holographic metal/superconductor phase transition model

    E-Print Network [OSTI]

    Yan Peng; Yunqi Liu

    2015-03-03T23:59:59.000Z

    We study the scalar condensation of a general holographic superconductor model in AdS black hole background away from the probe limit. We find the model parameters together with the scalar mass and backreaction can determine the order of phase transitions completely. In addition, we observe two types of discontinuities of the scalar operator in the case of first order phase transitions. We analyze in detail the effects of the scalar mass and backreaction on the formation of discontinuities and arrive at an approximate relation between the threshold model parameters. Furthermore, we obtain superconductor solutions corresponding to higher energy states and examine the stability of these superconductor solutions.

  6. Fabrication of carbon nanotube films from alkyne-transition metal complexes

    DOE Patents [OSTI]

    Iyer, Vivekanantan S. (Delft, NL); Vollhardt, K. Peter C. (Oakland, CA)

    2007-08-28T23:59:59.000Z

    A simple method for the production or synthesis of carbon nanotubes as free-standing films or nanotube mats by the thermal decomposition of transition metal complexed alkynes with aryl, alkyl, alkenyl, or alkynyl substituents. In particular, transition metal (e.g. Co, Ni, Fe, Mo) complexes of diarylacetylenes, e.g. diphenylacetylene, and solid mixtures of these complexes with suitable, additional carbon sources are heated in a vessel. More specifically, the heating of the transition metal complex is completed at a temperature between 400-800.degree. C. and more particularly 550-700.degree. C. for between 0.1 to 24 hours and more particularly 0.5-3 hours in a sealed vessel under a partial pressure of argon or helium.

  7. M5Si3(M=Ti, Nb, Mo) Based Transition-Metal Silicides for High Temperature Applications

    SciTech Connect (OSTI)

    Zhihong Tang

    2007-12-01T23:59:59.000Z

    Transition metal silicides are being considered for future engine turbine components at temperatures up to 1600 C. Although significant improvement in high temperature strength, room temperature fracture toughness has been realized in the past decade, further improvement in oxidation resistance is needed. Oxidation mechanism of Ti{sub 5}Si{sub 3}-based alloys was investigated. Oxidation behavior of Ti{sub 5}Si{sub 3}-based alloy strongly depends on the atmosphere. Presence of Nitrogen alters the oxidation behavior of Ti{sub 5}Si{sub 3} by nucleation and growth of nitride subscale. Ti{sub 5}Si{sub 3.2} and Ti{sub 5}Si{sub 3}C{sub 0.5} alloys exhibited an excellent oxidation resistance in nitrogen bearing atmosphere due to limited dissolution of nitrogen and increased Si/Ti activity ratio. MoSi{sub 2} coating developed by pack cementation to protect Mo-based Mo-Si-B composites was found to be effective up to 1500 C. Shifting coating composition to T1+T2+Mo{sub 3}Si region showed the possibility to extend the coating lifetime above 1500 C by more than ten times via formation of slow growing Mo{sub 3}Si or T2 interlayer without sacrificing the oxidation resistance of the coating. The phase equilibria in the Nb-rich portion of Nb-B system has been evaluated experimentally using metallographic analysis and differential thermal analyzer (DTA). It was shown that Nb{sub ss} (solid solution) and NbB are the only two primary phases in the 0-40 at.% B composition range, and the eutectic reaction L {leftrightarrow} Nb{sub SS} + NbB was determined to occur at 2104 {+-} 5 C by DTA.

  8. Studies of high temperature ternary phases in mixed-metal-rich early transition metal sulfide and phosphide systems

    SciTech Connect (OSTI)

    Marking, G.A.

    1994-01-04T23:59:59.000Z

    Investigations of ternary mixed early transition metal-rich sulfide and phosphide systems resulted in the discovery of new structures and new phases. A new series of Zr and Hf - group V transition metal - sulfur K-phases was synthesized and crystallographically characterized. When the group V transition metal was Nb or Ta, the unit cell volume was larger than any previously reported K-phase. The presence of adventitious oxygen was determined in two K-phases through a combination of neutron scattering and X-ray diffraction experiments. A compound Hf{sub 10}Ta{sub 3}S{sub 3} was found to crystallize in a new-structure type similar to the known gamma brasses. This structure is unique in that it is the only reported {open_quotes}stuffed{close_quotes} gamma-brass type structure. The metal components, Hf and Ta, are larger in size and more electropositive than the metals found in normal gamma brasses (e.g. Cu and Zn) and because of the larger metallic radii, sulfur can be incorporated into the structure where it plays an integral role in stabilizing this phase relative to others. X-ray single-crystal, X-ray powder and neutron powder refinements were performed on this structure. A new structure was found in the ternary Nb-Zr-P system which has characteristics in common with many known early transition metal-rich sulfides, selenides, and phosphides. This structure has the simplest known interconnection of the basic building blocks known for this structural class. Anomalous scattering was a powerful tool for differentiating between Zr and Nb when using Mo K{alpha} X-radiation. The compounds ZrNbP and HfNbP formed in the space group Prima with the simple Co{sub 2}Si structure which is among the most common structures found for crystalline solid materials. Solid solution compounds in the Ta-Nb-P, Ta-Zr-P, Nb-Zr-P, Hf-Nb-P, and Hf-Zr-S systems were crystallographically characterized. The structural information corroborated ideas about bonding in metal-rich compounds.

  9. Recycling of rare earth metals from rare earth-transition metal alloy scrap by liquid metal extraction

    DOE Patents [OSTI]

    Ellis, T.W.; Schmidt, F.A.

    1995-08-01T23:59:59.000Z

    A method is described for treating rare earth metal-bearing scrap, waste or other material (e.g. Nd--Fe--B or Dy--Tb--Fe scrap) to recover the rare earth metal comprising melting the rare earth metal-bearing material, melting a Group IIA metal extractant, such as Mg, Ca, or Ba, in which the rare earth is soluble in the molten state, and contacting the melted material and melted extractant at a temperature and for a time effective to extract the rare earth from the melted material into the melted extractant. The rare earth metal is separated from the extractant metal by vacuum sublimation or distillation. 2 figs.

  10. Recycling of rare earth metals from rare earth-transition metal alloy scrap by liquid metal extraction

    DOE Patents [OSTI]

    Ellis, Timothy W. (Ames, IA); Schmidt, Frederick A. (Ames, IA)

    1995-08-01T23:59:59.000Z

    Method of treating rare earth metal-bearing scrap, waste or other material (e.g. Nd--Fe--B or Dy--Tb--Fe scrap) to recover the rare earth metal comprising melting the rare earth metal-bearing material, melting a Group IIA metal extractant, such as Mg, Ca, or Ba, in which the rare earth is soluble in the molten state, and contacting the melted material and melted extractant at a temperature and for a time effective to extract the rare earth from the melted material into the melted extractant. The rare earth metal is separated from the extractant metal by vacuum sublimation or distillation.

  11. Electronically conducting metal oxide nanoparticles and films for optical sensing applications

    SciTech Connect (OSTI)

    Ohodnicki, Jr., Paul R.; Wang, Congjun; Andio, Mark A

    2014-09-16T23:59:59.000Z

    The disclosure relates to a method of detecting a change in a chemical composition by contacting a conducting oxide material with a monitored stream, illuminating the conducting oxide material with incident light, collecting exiting light, monitoring an optical signal based on a comparison of the incident light and the exiting light, and detecting a shift in the optical signal. The conducting metal oxide has a carrier concentration of at least 10.sup.17/cm.sup.3, a bandgap of at least 2 eV, and an electronic conductivity of at least 10.sup.-1 S/cm, where parameters are specified at the gas stream temperature. The optical response of the conducting oxide materials is proposed to result from the high carrier concentration and electronic conductivity of the conducting metal oxide, and the resulting impact of changing gas atmospheres on that relatively high carrier concentration and electronic conductivity. These changes in effective carrier densities and electronic conductivity of conducting metal oxide films and nanoparticles are postulated to be responsible for the change in measured optical absorption associated with free carriers. Exemplary conducting metal oxides include but are not limited to Al-doped ZnO, Sn-doped In.sub.2O.sub.3, Nb-doped TiO.sub.2, and F-doped SnO.sub.2.

  12. Plasmonic transparent conducting metal oxide nanoparticles and films for optical sensing applications

    DOE Patents [OSTI]

    Ohodnicki, Jr., Paul R; Wang, Congjun; Andio, Mark A

    2014-01-28T23:59:59.000Z

    The disclosure relates to a method of detecting a change in a chemical composition by contacting a doped oxide material with a monitored stream, illuminating the doped oxide material with incident light, collecting exiting light, monitoring an optical signal based on a comparison of the incident light and the exiting light, and detecting a shift in the optical signal. The doped metal oxide has a carrier concentration of at least 10.sup.18/cm.sup.3, a bandgap of at least 2 eV, and an electronic conductivity of at least 10.sup.1 S/cm, where parameters are specified at a temperature of 25.degree. C. The optical response of the doped oxide materials results from the high carrier concentration of the doped metal oxide, and the resulting impact of changing gas atmospheres on that relatively high carrier concentration. These changes in effective carrier densities of conducting metal oxide nanoparticles are postulated to be responsible for the change in measured optical absorption associated with free carriers. Exemplary doped metal oxides include but are not limited to Al-doped ZnO, Sn-doped In.sub.2O.sub.3, Nb-doped TiO.sub.2, and F-doped SnO.sub.2.

  13. Steam Reforming on Transition-metal Carbides from Density-functional Theory

    SciTech Connect (OSTI)

    Vojvodic, Aleksandra

    2012-05-11T23:59:59.000Z

    A screening study of the steam reforming reaction on clean and oxygen covered early transition-metal carbides surfaces is performed by means of density-functional theory calculations. It is found that carbides provide a wide spectrum of reactivities, from too reactive via suitable to too inert. Several molybdenum-based systems are identified as possible steam reforming catalysts. The findings suggest that carbides provide a playground for reactivity tuning, comparable to the one for pure metals.

  14. Composite catalyst for carbon monoxide and hydrocarbon oxidation

    DOE Patents [OSTI]

    Liu, Wei (Cambridge, MA); Flytzani-Stephanopoulos, Maria (Winchester, MA)

    1996-01-01T23:59:59.000Z

    A method and composition for the complete oxidation of carbon monoxide and/or hydrocarbon compounds. The method involves reacting the carbon monoxide and/or hydrocarbons with an oxidizing agent in the presence of a metal oxide composite catalyst. The catalyst is prepared by combining fluorite-type oxygen ion conductors with active transition metals. The fluorite oxide, selected from the group consisting of cerium oxide, zirconium oxide, thorium oxide, hafnium oxide, and uranium oxide, and may be doped by alkaline earth and rare earth oxides. The transition metals, selected from the group consisting of molybdnum, copper, cobalt, maganese, nickel, and silver, are used as additives. The atomic ratio of transition metal to fluorite oxide is less than one.

  15. Composite catalyst for carbon monoxide and hydrocarbon oxidation

    DOE Patents [OSTI]

    Liu, W.; Flytzani-Stephanopoulos, M.

    1996-03-19T23:59:59.000Z

    A method and composition are disclosed for the complete oxidation of carbon monoxide and/or hydrocarbon compounds. The method involves reacting the carbon monoxide and/or hydrocarbons with an oxidizing agent in the presence of a metal oxide composite catalyst. The catalyst is prepared by combining fluorite-type oxygen ion conductors with active transition metals. The fluorite oxide, selected from the group consisting of cerium oxide, zirconium oxide, thorium oxide, hafnium oxide, and uranium oxide, and may be doped by alkaline earth and rare earth oxides. The transition metals, selected from the group consisting of molybdenum, copper, cobalt, manganese, nickel, and silver, are used as additives. The atomic ratio of transition metal to fluorite oxide is less than one.

  16. Heteroepitaxial VO{sub 2} thin films on GaN: Structure and metal-insulator transition characteristics

    SciTech Connect (OSTI)

    Zhou You; Ramanathan, Shriram [Harvard School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138 (United States)

    2012-10-01T23:59:59.000Z

    Monolithic integration of correlated oxide and nitride semiconductors may open up new opportunities in solid-state electronics and opto-electronics that combine desirable functional properties of both classes of materials. Here, we report on epitaxial growth and phase transition-related electrical properties of vanadium dioxide (VO{sub 2}) thin films on GaN epitaxial layers on c-sapphire. The epitaxial relation is determined to be (010){sub vo{sub 2}} parallel (0001){sub GaN} parallel (0001){sub A1{sub 2O{sub 3}}} and [100]{sub vo{sub 2}} parallel [1210]{sub GaN} parallel [0110]{sub A1{sub 2O{sub 3}}} from x-ray diffraction. VO{sub 2} heteroepitaxial growth and lattice mismatch are analyzed by comparing the GaN basal plane (0001) with the almost close packed corrugated oxygen plane in vanadium dioxide and an experimental stereographic projection describing the orientation relationship is established. X-ray photoelectron spectroscopy suggests a slightly oxygen rich composition at the surface, while Raman scattering measurements suggests that the quality of GaN layer is not significantly degraded by the high-temperature deposition of VO{sub 2}. Electrical characterization of VO{sub 2} films on GaN indicates that the resistance changes by about four orders of magnitude upon heating, similar to epitaxial VO{sub 2} films grown directly on c-sapphire. It is shown that the metal-insulator transition could also be voltage-triggered at room temperature and the transition threshold voltage scaling variation with temperature is analyzed in the framework of a current-driven Joule heating model. The ability to synthesize high quality correlated oxide films on GaN with sharp phase transition could enable new directions in semiconductor-photonic integrated devices.

  17. Metal-insulator transition in silicon MOSFETs: new viewpoint

    E-Print Network [OSTI]

    Fominov, Yakov

    .T. Dolgopolov, PRB 33, 1076 (1986). / =-kT/EF C(n s) G. Zala, B. Narozhny, I.L. Aleiner PRB 64.A. Shashkin, S.V. Kravchenko, V.T. Dolgopolov, and T.M. Klapwijk, PRB, 66, 073303 (2002) (T)/=1-AkT, gm = ?2ns in a metallic 2D electron system. A.A. Shashkin, S.V. Kravchenko, V.T. Dolgopolov, and T.M. Klapwijk, PRB, 66

  18. Use of Transition Metal Forms in Separation of Lipid Components 

    E-Print Network [OSTI]

    Kulkarni, Sayali V

    2014-08-01T23:59:59.000Z

    , Uwagawa, & Nakai, 1994). For example, supercritical extraction (SC) has been used to extract polyunsaturated fatty acid ethyl esters (PUFA-Et) from aqueous silver nitrate (Suzuki, Tanaka, Kato, & Nagahama, 1994) while separation of ethyl esters... of eicosapentaenoic acid and docosahexaenoic acid has been attempted via circulating liquid membranes using silver nitrate as a carrier (Teramoto, Matsuyama, & Nakai, 1996). Certain metallic ions demonstrate the ability to form precipitates with specific types...

  19. Metal oxide/organic interface investigations for photovoltaic devices

    E-Print Network [OSTI]

    Pachoumi, Olympia

    2014-10-07T23:59:59.000Z

    organic photovoltaics is investigated. We show that using these ternary oxides can lead to superior devices by: prevent- ing a dipole forming between the oxide and the active organic layer in a model ZnMO / P3HT:PCBM OPV as well as lead to improved surface...

  20. Method of nitriding, carburizing, or oxidizing refractory metal articles using microwaves

    DOE Patents [OSTI]

    Holcombe, Cressie E. (Knoxville, TN); Dykes, Norman L. (Oak Ridge, TN); Tiegs, Terry N. (Lenoir City, TN)

    1992-01-01T23:59:59.000Z

    A method of nitriding an article of refractory-nitride-forming metal or metalloids. A consolidated metal or metalloid article is placed inside a microwave oven and nitrogen containing gas is introduced into the microwave oven. The metal or metalloid article is heated to a temperature sufficient to react the metal or metalloid with the nitrogen by applying a microwave energy within the microwave oven. The metal or metalloid article is maintained at that temperature for a period of time sufficient to convert the article of metal or metalloid to an article of refractory nitride. in addition, a method of applying a coating, such as a coating of an oxide, a carbide, or a carbo-nitride, to an article of metal or metalloid by microwave heating.

  1. Sharp semiconductor-to-metal transition of VO{sub 2} thin films on glass substrates

    SciTech Connect (OSTI)

    Jian, Jie; Chen, Aiping [Department of Electrical and Computer Engineering, Texas A and M University, College Station, Texas 77843-3128 (United States); Zhang, Wenrui [Material Science and Engineering Program, Texas A and M University, College Station, Texas 77843-3128 (United States); Wang, Haiyan, E-mail: wangh@ece.tamu.edu [Department of Electrical and Computer Engineering, Texas A and M University, College Station, Texas 77843-3128 (United States); Material Science and Engineering Program, Texas A and M University, College Station, Texas 77843-3128 (United States)

    2013-12-28T23:59:59.000Z

    Outstanding phase transition properties of vanadium dioxide (VO{sub 2}) thin films on amorphous glass were achieved and compared with the ones grown on c-cut sapphire and Si (111) substrates, all by pulsed laser deposition. The films on glass substrate exhibit a sharp semiconductor-to-metal transition (?4.3?°C) at a near bulk transition temperature of ?68.4?°C with an electrical resistance change as high as 3.2?×?10{sup 3} times. The excellent phase transition properties of the films on glass substrate are correlated with the large grain size and low defects density achieved. The phase transition properties of VO{sub 2} films on c-cut sapphire and Si (111) substrates were found to be limited by the high defect density.

  2. Tuning of the Metal-Insulator Transition via Alkali Adsorption

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron Spin Transition in2,EHSS A-Zand Analysis Utilities (TAU) References

  3. Tuning of the Metal-Insulator Transition via Alkali Adsorption

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron Spin Transition in2,EHSS A-Zand Analysis Utilities (TAU)

  4. Tuning of the Metal-Insulator Transition via Alkali Adsorption

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron Spin Transition in2,EHSS A-Zand Analysis Utilities (TAU)Tuning of the

  5. Fabrication of superconducting metal-oxide textiles by heating impregnated polymeric material in a weakly oxidizing atmosphere

    SciTech Connect (OSTI)

    Van den Sype, J.S.

    1993-07-13T23:59:59.000Z

    A process is described for producing crystalline fibers, textiles or shapes comprised of YBa[sub 2]Cu[sub 3]O[sub 7[minus]x] where x varies from about 0 to about 0.4, said process comprising: (a) impregnating a preformed organic polymeric material with three metal compounds to provide metal elements in said material in substantially the atomic ratio occurring in said YBa[sub 2]Cu[sub 3]O[sub 7[minus]x]; (b) heating said impregnated material in a weakly oxidizing atmosphere containing from about 0.05% to about 2% oxygen by volume to a temperature sufficiently high to at least partially pyrolize and oxidize said organic material and at least partially oxidize said metal compounds substantially without ignition of said organic material and without formation of a molten phase or reaching a decomposition temperature of said YBa[sub 2]Cu[sub 3]O[sub 7[minus]x]; and (c) cooling the resulting material in at least a moderately oxidizing atmosphere to room temperature so as to obtain said fibers, textiles or shapes.

  6. Hybrid Car-Parrinello/Molecular Mechanics Modelling of Transition Metal Complexes: Structure, Dynamics and Reactivity

    E-Print Network [OSTI]

    Guidoni, Leonardo

    Hybrid Car-Parrinello/Molecular Mechanics Modelling of Transition Metal Complexes: Structure). We have recently developed a QM/MM extension of a Car-Parrinello scheme [5]. These hybrid Car functional theory embedded in a classical force field description. The power of such a combined Car

  7. Chemical bonding of hydrogen molecules to transition metal complexes

    SciTech Connect (OSTI)

    Kubas, G.J.

    1990-01-01T23:59:59.000Z

    The complex W(CO){sub 3}(PR{sub 3}){sub 2}(H{sub 2}) (CO = carbonyl; PR{sub 3} = organophosphine) was prepared and was found to be a stable crystalline solid under ambient conditions from which the hydrogen can be reversibly removed in vacuum or under an inert atmosphere. The weakly bonded H{sub 2} exchanges easily with D{sub 2}. This complex represents the first stable compound containing intermolecular interaction of a sigma-bond (H-H) with a metal. The primary interaction is reported to be donation of electron density from the H{sub 2} bonding electron pair to a vacant metal d-orbital. A series of complexes of molybdenum of the type Mo(CO)(H{sub 2})(R{sub 2}PCH{sub 2}CH{sub 2}PR{sub 2}){sub 2} were prepared by varying the organophosphine substitutent to demonstrate that it is possible to bond either dihydrogen or dihydride by adjusting the electron-donating properties of the co-ligands. Results of infrared and NMR spectroscopic studies are reported. 20 refs., 5 fig.

  8. Holographic entanglement entropy in metal/superconductor phase transition with Born-Infeld electrodynamics

    E-Print Network [OSTI]

    Weiping Yao; Jiliang Jing

    2014-08-11T23:59:59.000Z

    We investigate the holographic entanglement entropy in the metal/superconductor phase transition for the Born-Infeld electrodynamics with full backreaction and note that the entropy is a good probe to study the properties of the phase transition. For the operator $$, we find that the entanglement entropy decreases (or increases) with the increase of the Born-Infeld parameter $b$ in the metal (or superconducting) phase. For the operator $$, we observe that, with the increase of the Born-Infeld parameter, the entanglement entropy in the metal phase decreases monotonously but the entropy in the superconducting phase first increases and forms a peak at some threshold $b_{T}$, then decreases continuously. Moreover, the value of $b_{T}$ becomes smaller as the width of the subsystem $A$ decreases.

  9. Transition metal-catalyzed process for addition of amines to carbon-carbon double bonds

    DOE Patents [OSTI]

    Hartwig, John F. (Durham, CT); Kawatsura, Motoi (Chatham, NJ); Loeber, Oliver (New Haven, CT)

    2002-01-01T23:59:59.000Z

    The present invention is directed to a process for addition of amines to carbon-carbon double bonds in a substrate, comprising: reacting an amine with a compound containing at least one carbon-carbon double bond in the presence a transition metal catalyst under reaction conditions effective to form a product having a covalent bond between the amine and a carbon atom of the former carbon-carbon double bond. The transition metal catalyst comprises a Group 8 metal and a ligand containing one or more 2-electron donor atoms. The present invention is also directed to enantioselective reactions of amine compounds with compounds containing carbon-carbon double bonds, and a calorimetric assay to evaluate potential catalysts in these reactions.

  10. Lattice site and thermal stability of transition metals in germanium

    E-Print Network [OSTI]

    Augustyns, Valérie; Pereira, Lino

    Although the first transistor was based on germanium, current chip technology mainly uses silicon due to its larger abundance, a lower price and higher quality silicon-oxide. However, a very important goal in microelectronics is to obtain faster integrated circuits. The advantages of germanium compared to silicon (e.g. a higher mobility of the charge carriers) motivates further research on germanium based materials. Semiconductor doping (e.g. introducing impurities into silicon and germanium in order to alter - and control - their properties) can be done by ion implantation or by in situ doping, whereby the host material is doped during growth. This thesis focuses on introducing dopants by ion implantation. The implantation as well as the subsequent measurements were performed in ISOLDE (CERN) using the emission channeling technique. Although ion implantation generates undesired defects in the host material (e.g. vacancies), such damage can be reduced by performing the implantation at an elevated temperature....

  11. Surface Oxidation and Dissolution of Metal Nanocatalysts in Acid Medium

    E-Print Network [OSTI]

    Callejas-Tovar, Juan

    2012-10-19T23:59:59.000Z

    to study the degradation and dealloying in nanocatalysts. The results on the degradation of Pt nanoparticles under different potential regimes demonstrate that the dissolution depends on the potential path to which the nanocatalyst is exposed. Metal atoms...

  12. Mesoporous metal oxide microsphere electrode compositions and their methods of making

    DOE Patents [OSTI]

    Parans Paranthaman, Mariappan; Bi, Zhonghe; Bridges, Craig A; Brown, Gilbert M

    2014-12-16T23:59:59.000Z

    Compositions and methods of making are provided for treated mesoporous metal oxide microspheres electrodes. The compositions comprise (a) microspheres with an average diameter between 200 nanometers (nm) and 10 micrometers (.mu.m); (b) mesopores on the surface and interior of the microspheres, wherein the mesopores have an average diameter between 1 nm and 50 nm and the microspheres have a surface area between 50 m.sup.2/g and 500 m.sup.2/g, and wherein the composition has an electrical conductivity of at least 1.times.10.sup.-7 S/cm at 25.degree. C. and 60 MPa. The methods of making comprise forming a mesoporous metal oxide microsphere composition and treating the mesoporous metal oxide microspheres by at least one method selected from the group consisting of: (i) annealing in a reducing atmosphere, (ii) doping with an aliovalent element, and (iii) coating with a coating composition.

  13. Coherent/incoherent metal transition in a holographic model

    E-Print Network [OSTI]

    Keun-Young Kim; Kyung Kiu Kim; Yunseok Seo; Sang-Jin Sin

    2014-12-13T23:59:59.000Z

    We study AC electric($\\sigma$), thermoelectric($\\alpha$), and thermal($\\bar{\\kappa}$) conductivities in a holographic model, which is based on 3+1 dimensional Einstein-Maxwell-scalar action. There is momentum relaxation due to massless scalar fields linear to spatial coordinate. The model has three field theory parameters: temperature($T$), chemical potential($\\mu$), and effective impurity($\\beta$). At low frequencies, if $\\beta \\mu$ the shape of peak deviates from the Drude form(incoherent metal). At intermediate frequencies($T<\\omega<\\mu$), we have analysed numerical data of three conductivities($\\sigma, \\alpha, \\bar{\\kappa}$) for a wide variety of parameters, searching for scaling laws, which are expected from either experimental results on cuprates superconductors or some holographic models. In the model we study, we find no clear signs of scaling behaviour.

  14. Determination of Interfacial Adhesion Strength between Oxide Scale and Substrate for Metallic SOFC Interconnects

    SciTech Connect (OSTI)

    Sun, Xin; Liu, Wenning N.; Stephens, Elizabeth V.; Khaleel, Mohammad A.

    2008-01-21T23:59:59.000Z

    The interfacial adhesion strength between the oxide scale and the substrate is crucial to the reliability and durability of metallic interconnects in SOFC operating environments. It is necessary, therefore, to establish a methodology to quantify the interfacial adhesion strength between the oxide scale and the metallic interconnect substrate, and furthermore to design and optimize the interconnect material as well as the coating materials to meet the design life of an SOFC system. In this paper, we present an integrated experimental/analytical methodology for quantifying the interfacial adhesion strength between oxide scale and a ferritic stainless steel interconnect. Stair-stepping indentation tests are used in conjunction with subsequent finite element analyses to predict the interfacial strength between the oxide scale and Crofer 22 APU substrate.

  15. Spinel-structured metal oxide on a substrate and method of making same by molecular beam epitaxy

    DOE Patents [OSTI]

    Chambers, Scott A.

    2006-02-21T23:59:59.000Z

    A method of making a spinel-structured metal oxide on a substrate by molecular beam epitaxy, comprising the step of supplying activated oxygen, a first metal atom flux, and at least one other metal atom flux to the surface of the substrate, wherein the metal atom fluxes are individually controlled at the substrate so as to grow the spinel-structured metal oxide on the substrate and the metal oxide is substantially in a thermodynamically stable state during the growth of the metal oxide. A particular embodiment of the present invention encompasses a method of making a spinel-structured binary ferrite, including Co ferrite, without the need of a post-growth anneal to obtain the desired equilibrium state.

  16. Noble Metal Catalysts for Mercury Oxidation in Utility Flue Gas: Gold, Palladium and Platinum Formulations

    SciTech Connect (OSTI)

    Presto, A.A.; Granite, E.J

    2008-07-01T23:59:59.000Z

    The use of noble metals as catalysts for mercury oxidation in flue gas remains an area of active study. To date, field studies have focused on gold and palladium catalysts installed at pilot scale. In this article, we introduce bench-scale experimental results for gold, palladium and platinum catalysts tested in realistic simulated flue gas. Our initial results reveal some intriguing characteristics of catalytic mercury oxidation and provide insight for future research into this potentially important process.

  17. The chemistry of transition metal complexes related to solar energy storage : H? production and small molecule (CO? and HX; X = Cl, Br) chemistry.

    E-Print Network [OSTI]

    Lee, Changhoon, Ph. D. Massachusetts Institute of Technology

    2011-01-01T23:59:59.000Z

    The studies in this thesis have focused on the chemistry of transition metal complexes related to solar energy storage: electrochemical H? production, HX splitting and CO? activation mediated by transition metal complexes. ...

  18. Low temperature formation of electrode having electrically conductive metal oxide surface

    DOE Patents [OSTI]

    Anders, Simone (Albany, CA); Anders, Andre (Albany, CA); Brown, Ian G. (Berkeley, CA); McLarnon, Frank R. (Orinda, CA); Kong, Fanping (Berkeley, CA)

    1998-01-01T23:59:59.000Z

    A low temperature process is disclosed for forming metal suboxides on substrates by cathodic arc deposition by either controlling the pressure of the oxygen present in the deposition chamber, or by controlling the density of the metal flux, or by a combination of such adjustments, to thereby control the ratio of oxide to metal in the deposited metal suboxide coating. The density of the metal flux may, in turn, be adjusted by controlling the discharge current of the arc, by adjusting the pulse length (duration of on cycle) of the arc, and by adjusting the frequency of the arc, or any combination of these parameters. In a preferred embodiment, a low temperature process is disclosed for forming an electrically conductive metal suboxide, such as, for example, an electrically conductive suboxide of titanium, on an electrode surface, such as the surface of a nickel oxide electrode, by such cathodic arc deposition and control of the deposition parameters. In the preferred embodiment, the process results in a titanium suboxide-coated nickel oxide electrode exhibiting reduced parasitic evolution of oxygen during charging of a cell made using such an electrode as the positive electrode, as well as exhibiting high oxygen overpotential, resulting in suppression of oxygen evolution at the electrode at full charge of the cell.

  19. Metal regeneration of iron chelates in nitric oxide scrubbing

    DOE Patents [OSTI]

    Chang, Shih-Ger (El Cerrito, CA); Littlejohn, David (Oakland, CA); Shi, Yao (Berkeley, CA)

    1997-08-19T23:59:59.000Z

    The present invention relates to a process of using metal particles to reduce NO to NH.sub.3. More specifically, the invention concerns an improved process to regenerate iron (II) (CHELATE) by reduction of iron (II) (CHELATE) (NO) complex, which process comprises: a) contacting an aqueous solution containing iron (II) (CHELATE) (NO) with metal particles at between about 20.degree. and 90.degree. C. to reduce NO present, produce ammonia or an ammonium ion, and produce free iron (II) (CHELATE) at a pH of between about 3 and 8. The process is useful to remove NO from flue gas and reduce pollution.

  20. Metal regeneration of iron chelates in nitric oxide scrubbing

    DOE Patents [OSTI]

    Chang, S.G.; Littlejohn, D.; Shi, Y.

    1997-08-19T23:59:59.000Z

    The present invention relates to a process of using metal particles to reduce NO to NH{sub 3}. More specifically, the invention concerns an improved process to regenerate iron (II) (CHELATE) by reduction of iron (II) (CHELATE) (NO) complex, which process comprises: (a) contacting an aqueous solution containing iron (II) (CHELATE) (NO) with metal particles at between about 20 and 90 C to reduce NO present, produce ammonia or an ammonium ion, and produce free iron (II) (CHELATE) at a pH of between about 3 and 8. The process is useful to remove NO from flue gas and reduce pollution. 34 figs.

  1. Metallic magnetism and change of conductivity in the nano to bulk transition of cobalt ferrite

    SciTech Connect (OSTI)

    Arunkumar, A.; Vanidha, D.; Kannan, R., E-mail: kannan@pec.edu [Department of Physics, Pondicherry Engineering College, Puducherry–605 014 (India); Oudayakumar, K. [Department of Physics, Sri Manakula Vinayagar Engineering College, Puducherry–605 107 (India); Rajagopan, S. [Department of Chemistry, Pondicherry Engineering College, Puducherry–605 014 (India)

    2013-11-14T23:59:59.000Z

    Variations in conductivity with particle size have been observed in cobalt ferrite, when synthesized by solgel auto-combustion method. Impedance analysis reveals metallic and semiconducting behavior at room temperature for a particle size of 6?nm and 52?nm, respectively. Upon thermal activation, metallic to semiconducting phase transition has been observed as a function of particle size and vice-versa. Grainboundary Resistance (R{sub gb}), increased drastically with particle size (19?M? for 6?nm and 259?M? for 52?nm) at room temperature. AC conductivity and dielectric constants exhibit similar metallic to semiconducting phase transition at 6?nm and semiconducting behavior at 52?nm with temperature in the selected frequencies. Enhanced magnetic moment with an increase in the grain size along with decreased coercivity (1444?G to 1146?G) reveals transition from single domain to multi-domain. Increased inter-particle interaction is responsible for metallicity at the nano level and on the contrary semiconductivity is attributed to bulk.

  2. Supersaturating silicon with transition metals by ion implantation and pulsed laser melting

    SciTech Connect (OSTI)

    Recht, Daniel; Aziz, Michael J. [Harvard School of Engineering and Applied Sciences, Cambridge, Massachusetts 02138 (United States)] [Harvard School of Engineering and Applied Sciences, Cambridge, Massachusetts 02138 (United States); Smith, Matthew J.; Grade?ak, Silvija [Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)] [Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Charnvanichborikarn, Supakit; Williams, James S. [Research School of Physics and Engineering, The Australian National University, Canberra, ACT (Australia)] [Research School of Physics and Engineering, The Australian National University, Canberra, ACT (Australia); Sullivan, Joseph T.; Winkler, Mark T.; Buonassisi, Tonio [Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge Massachusetts 02139 (United States)] [Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge Massachusetts 02139 (United States); Mathews, Jay; Warrender, Jeffrey M. [Benet Laboratories, U.S. Army ARDEC, Watervliet, New York 12189 (United States)] [Benet Laboratories, U.S. Army ARDEC, Watervliet, New York 12189 (United States)

    2013-09-28T23:59:59.000Z

    We investigate the possibility of creating an intermediate band semiconductor by supersaturating Si with a range of transition metals (Au, Co, Cr, Cu, Fe, Pd, Pt, W, and Zn) using ion implantation followed by pulsed laser melting (PLM). Structural characterization shows evidence of either surface segregation or cellular breakdown in all transition metals investigated, preventing the formation of high supersaturations. However, concentration-depth profiling reveals that regions of Si supersaturated with Au and Zn are formed below the regions of cellular breakdown. Fits to the concentration-depth profile are used to estimate the diffusive speeds, v{sub D,} of Au and Zn, and put lower bounds on v{sub D} of the other metals ranging from 10{sup 2} to 10{sup 4} m/s. Knowledge of v{sub D} is used to tailor the irradiation conditions and synthesize single-crystal Si supersaturated with 10{sup 19} Au/cm{sup 3} without cellular breakdown. Values of v{sub D} are compared to those for other elements in Si. Two independent thermophysical properties, the solute diffusivity at the melting temperature, D{sub s}(T{sub m}), and the equilibrium partition coefficient, k{sub e}, are shown to simultaneously affect v{sub D}. We demonstrate a correlation between v{sub D} and the ratio D{sub s}(T{sub m})/k{sub e}{sup 0.67}, which is exhibited for Group III, IV, and V solutes but not for the transition metals investigated. Nevertheless, comparison with experimental results suggests that D{sub s}(T{sub m})/k{sub e}{sup 0.67} might serve as a metric for evaluating the potential to supersaturate Si with transition metals by PLM.

  3. Novel application of the CORAL software to model cytotoxicity of metal oxide nanoparticles to bacteria Escherichia coli

    E-Print Network [OSTI]

    Gini, Giuseppina

    Novel application of the CORAL software to model cytotoxicity of metal oxide nanoparticles 39217, USA h i g h l i g h t s " The CORAL software for the building up of QSPR/QSAR models is suggested. " The CORAL model for cytotoxicity of metal oxide nanoparticles is demonstrated. " The model is a mathematical

  4. Tuning the Bias Sensing Layer: A New Way to Greatly Improve Metal-Oxide Gas Sensors Selectivity

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    layer of resistive Metal-Oxide (MOX) sensors toward gases have been investigated. The behavior of a WO3 is kept constant, it has been found that tuning the polarization of the MOX layer induces changes on its the selectivity of MOX sensors. Keywords : Gas Sensor, Metal Oxide, Temperature-modulated, Bias-modulated I

  5. AlGaN/GaN metal-oxide-semiconductor heterostructure field-effect transistors using barium strontium titanate

    E-Print Network [OSTI]

    York, Robert A.

    AlGaN/GaN metal-oxide-semiconductor heterostructure field-effect transistors using barium strontium; published 13 October 2004) Use of high-k gate dielectrics in AlGaN/GaN heterostructure field transconductance and pinchoff voltage. To achieve this, AlGaN/GaN metal-oxide-semiconductor heterostructure field

  6. Process for making surfactant capped metal oxide nanocrystals, and products produced by the process

    DOE Patents [OSTI]

    Alivisatos, A. Paul; Rockenberger, Joerg

    2006-01-10T23:59:59.000Z

    Disclosed is a process for making surfactant capped nanocrystals of metal oxides which are dispersable in organic solvents. The process comprises decomposing a metal cupferron complex of the formula MXCupX, wherein M is a metal, and Cup is a N-substituted N-Nitroso hydroxylamine, in the presence of a coordinating surfactant, the reaction being conducted at a temperature ranging from about 150 to about 400.degree. C., for a period of time sufficient to complete the reaction. Also disclosed are compounds made by the process.

  7. Ag and Au atoms intercalated in bilayer heterostructures of transition metal dichalcogenides and graphene

    SciTech Connect (OSTI)

    Iyikanat, F., E-mail: fadiliyikanat@iyte.edu.tr; Senger, R. T. [Department of Physics, Izmir Institute of Technology, 35430 Izmir (Turkey); Sahin, H., E-mail: hasan.sahin@uantwerpen.be; Peeters, F. M. [Department of Physics, University of Antwerp, 2610 Antwerp (Belgium)

    2014-09-01T23:59:59.000Z

    The diffusive motion of metal nanoparticles Au and Ag on monolayer and between bilayer heterostructures of transition metal dichalcogenides and graphene are investigated in the framework of density functional theory. We found that the minimum energy barriers for diffusion and the possibility of cluster formation depend strongly on both the type of nanoparticle and the type of monolayers and bilayers. Moreover, the tendency to form clusters of Ag and Au can be tuned by creating various bilayers. Tunability of the diffusion characteristics of adatoms in van der Waals heterostructures holds promise for controllable growth of nanostructures.

  8. Light-Induced Metal-Insulator Transition in a Switchable Mirror

    SciTech Connect (OSTI)

    Hoekstra, A. F. Th.; Roy, A. S.; Rosenbaum, T. F.; Griessen, R.; Wijngaarden, R. J.; Koeman, N. J.

    2001-06-04T23:59:59.000Z

    Rare earth hydride films can be converted reversibly from metallic mirrors to insulating windows simply by changing the surrounding hydrogen gas pressure at room temperature. At low temperatures, in situ doping is not possible in this way as hydrogen cannot diffuse. However, our finding of persistent photoconductivity under ultraviolet illumination offers an attractive possibility to tune yttrium hydride through the T=0 metal-insulator transition. Conductivity and Hall measurements are used to determine critical exponents. The unusually large value for the product of the static and dynamical critical exponents appears to signify the important role played by electron-electron interactions.

  9. Observation of the Anderson Metal-Insulator Transition with Atomic Matter Waves: Theory and Experiment

    E-Print Network [OSTI]

    Gabriel Lemarié; Julien Chabé; Pascal Szriftgiser; Jean-Claude Garreau; Benoît Grémaud; Dominique Delande

    2009-07-20T23:59:59.000Z

    Using a cold atomic gas exposed to laser pulses -- a realization of the chaotic quasiperiodic kicked rotor with three incommensurate frequencies -- we study experimentally and theoretically the Anderson metal-insulator transition in three dimensions. Sensitive measurements of the atomic wavefunction and the use of finite-size scaling techniques make it possible to unambiguously demonstrate the existence of a quantum phase transition and to measure its critical exponents. By taking proper account of systematic corrections to one-parameter scaling, we show the universality of the critical exponent $\

  10. Mercury Removal from Aqueous Systems Using Commercial and Laboratory Prepared Metal Oxide Nanoparticles 

    E-Print Network [OSTI]

    Desai, Ishan

    2010-10-12T23:59:59.000Z

    Five commercial metal oxide nanoparticles (CuO, SiO2, Fe2O3, TiO2 and Al2O3) have been individually screened for mercury removal in a batch reactor under bicarbonate buffered and non-buffered aqueous solutions (DI water). ...

  11. HIGH-K-INAS METAL-OXIDE-SEMICONDUCTOR CAPACITORS FORMED BY ATOMIC-LAYER DEPOSITION

    E-Print Network [OSTI]

    -k-InAs metal-oxide-semiconductor capacitors. Devices are formed using various substrate pretreatments, film by the Terman method to be in the 1013 cm-2 -eV-1 range at midgap. TEM and XPS data suggest the high trap

  12. AC conductivity of nanoporous metal-oxide photoanodes for solar energy conversion

    E-Print Network [OSTI]

    Konezny, Steven J.

    AC conductivity of nanoporous metal-oxide photoanodes for solar energy conversion Steven J. Konezny% solar-to-electric energy conversion efficiency) exploited the large surface area of nanoporous thin for solar photoconversion is analyzed using a model based on fluctuation-induced tunneling conduction (FITC

  13. Electrochromic nickel oxide simultaneously doped with lithium and a metal dopant

    DOE Patents [OSTI]

    Gillaspie, Dane T; Weir, Douglas G

    2014-04-01T23:59:59.000Z

    An electrochromic device comprising a counter electrode layer comprised of lithium metal oxide which provides a high transmission in the fully intercalated state and which is capable of long-term stability, is disclosed. Methods of making an electrochromic device comprising such a counter electrode are also disclosed.

  14. Solution-mediated strategies for synthesizing metal oxides, borates and phosphides using nanocrystals as reactive precursors

    E-Print Network [OSTI]

    Henkes, Amanda Erin

    2009-05-15T23:59:59.000Z

    and phosphides using nanocrystalline precursors and solution-mediated techniques. Broadly, the strategies involve either 1) the formation of a nano-sized precursor in solution which is post-annealed after isolation to form a target metal oxide or borate or 2...

  15. Evaluation of Novel Ceria-Supported Metal Oxides As Oxygen Carriers for Chemical-Looping Combustion

    E-Print Network [OSTI]

    Azad, Abdul-Majeed

    for copper-based materials, and at 950 °C for iron- and manganese-based materials. Methane or syngas (50% COEvaluation of Novel Ceria-Supported Metal Oxides As Oxygen Carriers for Chemical-Looping Combustion of Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Goteborg, Sweden

  16. High density adsorbed oxygen on Rh,,111... and enhanced routes to metallic oxidation using atomic oxygen

    E-Print Network [OSTI]

    Sibener, Steven

    High density adsorbed oxygen on Rh,,111... and enhanced routes to metallic oxidation using atomic oxygen K. D. Gibson, Mark Viste, Errol C. Sanchez, and S. J. Sibener The James Franck Institute; accepted 30 November 1998 Exposure of Rh 111 to atomic oxygen leads to the facile formation of a full

  17. ANALYSIS OF THE ELECTRON EXCITATION SPECTRA IN HEAVY RARE EARTH METALS, HYDRIDES AND OXIDES

    E-Print Network [OSTI]

    Boyer, Edmond

    397 ANALYSIS OF THE ELECTRON EXCITATION SPECTRA IN HEAVY RARE EARTH METALS, HYDRIDES AND OXIDES C thin evaporated foils of heavy rare earths (Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) in three different chemical of high energy incident electrons (75 keV) transmitted through thin foils of yttric rare earth elements

  18. Oxidative stress in pied flycatcher (Ficedula hypoleuca) nestlings from metal contaminated environments in northern Sweden

    SciTech Connect (OSTI)

    Berglund, A.M.M. [Department of Ecology and Environmental Science, Umea University, SE-901 87 Umea (Sweden)], E-mail: asa.berglund@emg.umu.se; Sturve, J.; Foerlin, L. [Department of Zoology, Goeteborg University, Box 463, SE-405 30 Gothenburg (Sweden); Nyholm, N.E.I. [Department of Ecology and Environmental Science, Umea University, SE-901 87 Umea (Sweden)

    2007-11-15T23:59:59.000Z

    Metals have been shown to induce oxidative stress in animals. One of the most metal polluted terrestrial environments in Sweden is the surroundings of a sulfide ore smelter plant located in the northern part of the country. Pied flycatcher nestlings (Ficedula hypoleuca) that grew up close to the industry had accumulated amounts of arsenic, cadmium, mercury, lead, iron and zinc in their liver tissue. The aim of this study was to investigate if pied flycatcher nestlings in the pollution gradient of the industry were affected by oxidative stress using antioxidant molecules and enzyme activities. The antioxidant assays were also evaluated in search for useful biomarkers in pied flycatchers. This study indicated that nestlings in metal contaminated areas showed signs of oxidative stress evidenced by up regulated hepatic antioxidant defense given as increased glutathione reductase (GR) and catalase (CAT) activities and slightly but not significantly elevated lipid peroxidation and glutathione-S-transferase (GST) activities. Stepwise linear regression indicated that lipid peroxidation and CAT activities were influenced mostly by iron, but iron and lead influenced the CAT activity to a higher degree. Positive relationships were found between GST and lead as well as GR activities and cadmium. We conclude that GR, CAT, GST activities and lipid peroxidation levels may function as useful biomarkers for oxidative stress in free-living pied flycatcher nestlings exposed to metal contaminated environments.

  19. Criteria for Preparing and Packaging Plutonium Metals and Oxides for Long-Term Storage

    SciTech Connect (OSTI)

    NONE

    1994-12-01T23:59:59.000Z

    This Standard provides criteria for packaging of plutonium metals and stabilized oxides for storage periods of at least 50 years. To meet the criteria, plutonium-bearing materials must be in stable forms and be packaged in containers designed to maintain their integrity both under normal storage conditions and during anticipated handling accidents.

  20. Ternary Self-Assembly of Ordered Metal Oxide Graphene Nanocomposites for

    E-Print Network [OSTI]

    Aksay, Ilhan A.

    Ternary Self-Assembly of Ordered Metal Oxide Graphene Nanocomposites for Electrochemical Energy-assembled nanostructures, but success has been lim- ited to two-phase organic/inorganic hybrid materials, nanoparticles, or polymer-based nanocomposites.4,5,16,17 Recently, a range of nanoscale building blocks, including carbon

  1. Inorganic metal oxide/organic polymer nanocomposites and method thereof

    DOE Patents [OSTI]

    Gash, Alexander E.; Satcher, Joe H.; Simpson, Randy

    2004-03-30T23:59:59.000Z

    A synthetic method for preparation of hybrid inorganic/organic energetic nanocomposites is disclosed herein. The method employs the use of stable metal inorganic salts and organic solvents as well as an organic polymer with good solubility in the solvent system to produce novel nanocomposite energetic materials. In addition, fuel metal powders (particularly those that are oxophillic) can be incorporated into composition. This material has been characterized by thermal methods, energy-filtered transmission electron microscopy (EFTEM), N.sub.2 adsoprtion/desorption methods, and Fourier-Transform (FT-IR) spectroscopy. According to these characterization methods the organic polymer phase fills the nanopores of the composite material, providing superb mixing of the component phases in the energetic nanocomposite.

  2. Inorganic Metal Oxide/Organic Polymer Nanocomposites And Method Thereof

    DOE Patents [OSTI]

    Gash, Alexander E. (Livermore, CA); Satcher, Joe H. (Patterson, CA); Simpson, Randy (Livermore, CA)

    2004-11-16T23:59:59.000Z

    A synthetic method for preparation of hybrid inorganic/organic energetic nanocomposites is disclosed herein. The method employs the use of stable metal in organic salts and organic solvents as well as an organic polymer with good solubility in the solvent system to produce novel nanocomposite energetic materials. In addition, fuel metal powders (particularly those that are oxophilic) can be incorporated into composition. This material has been characterized by thermal methods, energy-filtered transmission electron microscopy (EFTEM), N.sub.2 adsoprtion/desorption methods, and Fourier-Transform (FT-IR) spectroscopy. According to these characterization methods the organic polymer phase fills the nanopores of the material, providing superb mixing of the component phases in the energetic nanocomposite.

  3. Magnetism of the rare earth, 3d --Theoretical review Abstract. --Compounds of rare earth and transition metals exhibit unusual and quite different behaviour. In

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    and secondly those determined mainly by rare earth metals. The first group are those rich in transition metal except TCo2, TNi5, T2Ni7, TNi3, TNi2. When the transition metal is magnetic, the coupling between rare-earth temperature are much smaller, and magnetic properties bear resemblances with rare earth metals. Thus we

  4. Systematic prediction of high-pressure melting curves of transition metals

    SciTech Connect (OSTI)

    Hieu, Ho Khac, E-mail: hieuhk@duytan.edu.vn [Institute of Research and Development, Duy Tan University, K7/25 Quang Trung, Danang (Viet Nam)

    2014-10-28T23:59:59.000Z

    The pressure effects on melting temperatures of transition metals have been studied based on the combination of the modified Lindemann criterion with statistical moment method in quantum statistical mechanics. Numerical calculations have been performed for five transition metals including Cu, Pd, Pt, Ni, and Mn up to pressure 100?GPa. Our results are in good and reasonable agreements with available experimental data. This approach gives us a relatively simple method for qualitatively calculating high-pressure melting temperature. Moreover, it can be used to verify future experimental and theoretical works. This research proposes the potential of the combination of statistical moment method and the modified Lindemann criterion on predicting high-pressure melting of materials.

  5. Synthesis of high {Tc} superconducting coatings and patterns by melt writing and oxidation of metallic precursor alloys

    DOE Patents [OSTI]

    Gao, W.; Vander Sande, J.B.

    1998-07-28T23:59:59.000Z

    A method is provided for fabrication of superconducting oxides and superconducting oxide composites and for joining superconductors to other materials. A coating of a molten alloy containing the metallic elements of the oxide is applied to a substrate surface and oxidized to form the superconducting oxide. A material can be contacted to the molten alloy which is subsequently oxidized joining the material to the resulting superconducting oxide coating. Substrates of varied composition and shape can be coated or joined by this method. 5 figs.

  6. Catalysts for the selective oxidation of hydrogen sulfide to sulfur

    DOE Patents [OSTI]

    Srinivas, Girish (Thornton, CO); Bai, Chuansheng (Baton Rouge, LA)

    2000-08-08T23:59:59.000Z

    This invention provides catalysts for the oxidation of hydrogen sulfide. In particular, the invention provides catalysts for the partial oxidation of hydrogen sulfide to elemental sulfur and water. The catalytically active component of the catalyst comprises a mixture of metal oxides containing titanium oxide and one or more metal oxides which can be selected from the group of metal oxides or mixtures of metal oxides of transition metals or lanthanide metals. Preferred metal oxides for combination with TiO.sub.2 in the catalysts of this invention include oxides of V, Cr, Mn, Fe, Co, Ni, Cu, Nb, Mo, Tc, Ru, Rh, Hf, Ta, W, Au, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. Catalysts which comprise a homogeneous mixture of titanium oxide and niobium (Nb) oxide are also provided. A preferred method for preparing the precursor homogenous mixture of metal hydroxides is by coprecipitation of titanium hydroxide with one or more other selected metal hydroxides. Catalysts of this invention have improved activity and/or selectivity for elemental sulfur production. Further improvements of activity and/or selectivity can be obtained by introducing relatively low amounts (up to about 5 mol %)of a promoter metal oxide (preferably of metals other than titanium and that of the selected second metal oxide) into the homogeneous metal/titanium oxide catalysts of this invention.

  7. Measurement of the Nickel/Nickel Oxide Phase Transition in High Temperature Hydrogenated Water Using the Contact Electric Resistance (CER) Technique

    SciTech Connect (OSTI)

    S.A. Attanasio; D.S. Morton; M.A. Ando; N.F. Panayotou; C.D. Thompson

    2001-05-08T23:59:59.000Z

    Prior studies of Alloy 600 and Alloy X-750 have shown the existence of a maximum in stress corrosion cracking (SCC) susceptibility in high temperature water (e.g., at 360 C), when testing is conducted over a range of dissolved (i.e., aqueous) hydrogen (H{sub 2}) concentrations. It has also been shown that this maximum in SCC susceptibility tends to occur in proximity to the nickel/nickel oxide (Ni/NiO) phase transition, suggesting that oxide phase stability may affect primary water SCC (PWSCC) resistance. Previous studies have estimated the Ni/NiO transition using thermodynamic calculations based on free energies of formation for NiO and H{sub 2}O. The present study reports experimental measurements of the Ni/NiO transition performed using a contact electric resistance (CER) instrument. The CER is capable of measuring the surface resistance of a metal to determine whether it is oxide-covered or oxide-free at a given condition. The transition aqueous hydrogen (H{sub 2}) concentration corresponding to the Ni/NiO equilibrium was measured at 288, 316, 338 and 360 C using high purity Ni specimens. The results showed an appreciable deviation (i.e., 7 to 58 scc H{sub 2}/kg H{sub 2}O) between the measured Ni/NiO transition and the theoretical Ni/NiO transition previously calculated using free energy data from the Journal of Solution Chemistry. The CER-measured position of the Ni/NiO transition is in good agreement with the maxima in PWSCC susceptibility at 338 and 360 C. The measured Ni/NiO transition provides a reasonable basis for estimating the aqueous H{sub 2} level at which the maximum in SCC susceptibility is likely to be observed at temperatures lower than 338 to 360 C, at which SCC tests are time-consuming to perform. Limited SCC data are presented which are consistent with the observation that SCC susceptibility is maximized near the Ni/NiO transition at 288 C.

  8. Electrospun and oxidized cellulose materials for environmental remediation of heavy metals in groundwater

    SciTech Connect (OSTI)

    Han, Dong [Stony Brook University (SUNY); Halada, Gary P. [Stony Brook University (SUNY); Spalding, Brian Patrick [ORNL; Brooks, Scott C [ORNL

    2009-12-01T23:59:59.000Z

    This chapter focuses on the use of modified cellulosic materials in the field of environmental remediation. Two different chemical methods were involved in fabricating oxidized cellulose (OC), which has shown promise as a metal ion chelator in environmental applications. Electrospinning was utilized to introduce a more porous structure into an oxidized cellulose matrix. FTIR and Raman spectroscopy were used to study both the formation of OC and its surface complexation with metal ions. IR and Raman spectroscopic data demonstrate the formation of characteristic carboxylic groups in the structure of the final products and the successful formation of OC-metal complexes. Subsequent field tests at the Field Research Site at Oak Ridge National Laboratory confirmed the value of OC for sorption of both U and Th ions.

  9. The Interactions and Exchanges of Metal-bound Sulfur Containing Ligands with Various Transition Metals

    E-Print Network [OSTI]

    Foley, William

    2011-02-22T23:59:59.000Z

    ............................................................... 11 3. M(CO) X ADDUCTS OF ZINC (II) AND CADMIUM (II) BIOMIMETIC COMPLEXES ..................................................................................................... 15 Conclusions for Section 3... ....... 26 Figure 4-1 The zinc-platinum adduct (a) and the metal exchange product (b) ... 29 Figure 4-2 Previously studied reactions of zinc and nickel biomimetic pathways 31 Figure 4-3 The ligand cannibalism of Zn-1?-Ac to form the diacetate...

  10. Gas-phase ultraviolet photoelectron spectroscopy and molecular orbital calculations on transition metal carbonyls and nitrosyls

    E-Print Network [OSTI]

    Morris-Sherwood, Betty Jeanne

    1981-01-01T23:59:59.000Z

    GAS-PHASE ULTRAVIOLET PHOTOELECTRON SPECTROSCOPY AND MOLECULAR ORBITAL CALCULATIONS ON TRANSITION METAL CARBONYLS AND NITROSYLS A Thesis by BETTY JEANNE MORRIS-SHERWOOD Submitted to the Graduate College of Texas ARM Uni ver s i ty in partial... JEANNE MORRIS-SHERWOOD Approved as to sty1e and content by: (Chairman of Committee) (Member): (Niember) r / )g (Head of Department) December 1981 ABSTRACT Gas-Phas Ultraviolet Photoelectron Spectroscopy and Molecular Orbital Calculations...

  11. Investigation of some new hydro(solvo)thermal synthesis routes to nanostructured mixed-metal oxides

    SciTech Connect (OSTI)

    Burnett, David L.; Harunsani, Mohammad H. [Department of Chemistry, University of Warwick, Coventry CV4 7AL (United Kingdom); Kashtiban, Reza J. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Playford, Helen Y. [Department of Chemistry, University of Warwick, Coventry CV4 7AL (United Kingdom); Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); ISIS Facility, Rutherford Appleton Laboratory, Didcot OX11 0QX (United Kingdom); Sloan, Jeremy [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Hannon, Alex C. [ISIS Facility, Rutherford Appleton Laboratory, Didcot OX11 0QX (United Kingdom); Walton, Richard I., E-mail: r.iwalton@warwick.ac.uk [Department of Chemistry, University of Warwick, Coventry CV4 7AL (United Kingdom)

    2014-06-01T23:59:59.000Z

    We present a study of two new solvothermal synthesis approaches to mixed-metal oxide materials and structural characterisation of the products formed. The solvothermal oxidation of metallic gallium by a diethanolamine solution of iron(II) chloride at 240 °C produces a crystalline sample of a spinel-structured material, made up of nano-scale particles typically 20 nm in dimension. XANES spectroscopy at the K-edge shows that the material contains predominantly Fe{sup 2+} in an octahedral environment, but that a small amount of Fe{sup 3+} is also present. Careful analysis using transmission electron microscopy and powder neutron diffraction shows that the sample is actually a mixture of two spinel materials: predominantly (>97%) an Fe{sup 2+} phase Ga{sub 1.8}Fe{sub 1.2}O{sub 3.9}, but with a minor impurity phase that is iron-rich. In contrast, the hydrothermal reaction of titanium bis(ammonium lactato)dihydroxide in water with increasing amounts of Sn(IV) acetate allows nanocrystalline samples of the SnO{sub 2}–TiO{sub 2} solid solution to be prepared directly, as proved by powder XRD and Raman spectroscopy. - Graphical abstract: New solvothermal synthesis approaches to spinel and rutile mixed-metal oxides are reported. - Highlights: • Solvothermal oxidation of gallium metal in organic iron(II) solution gives a novel iron gallate spinel. • Hydrothermal reaction of titanium(IV) complex and tin(IV) acetate produces the complete SnO{sub 2}–TiO{sub 2} solid solution. • Nanostructured mixed-metal oxide phases are produced directly from solution.

  12. Metal Current Collector Protected by Oxide Film - Energy Innovation Portal

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHighand Retrievals from aRod EggertMercuryAdvanced Materials AdvancedMetal

  13. Color-control of the persistent luminescence of cadmium silicate doped with transition metals

    SciTech Connect (OSTI)

    Abreu, Carolina M., E-mail: carolabreu.fisica@gmail.com [Laboratory of Advanced Ceramics Materials, Physics Department, Federal University of Sergipe, 49100-000 São Cristóvão, SE (Brazil); Silva, Ronaldo S.; Valerio, Mário E.G.; Macedo, Zélia S. [Laboratory of Advanced Ceramics Materials, Physics Department, Federal University of Sergipe, 49100-000 São Cristóvão, SE (Brazil)

    2013-04-15T23:59:59.000Z

    The structural and optical characterization of cadmium silicate (CdSiO{sub 3}) doped with transition metals is reported. This crystalline system presents intrinsic luminescence and is usually studied as host matrix for rare earth ions. In this work, CdSiO{sub 3} was doped with Mn, Ni and Cr to produce multicolored luminescent materials. Single crystalline CdSiO{sub 3} was obtained via solid state synthesis at 1000 °C/8 h. The valence of the dopants inserted in the host matrix was determined via XANES as 3+ for Cr, 2+ for Ni and both 2+ and 3+ for Mn, according to XANES studies. The optical absorption spectra of the samples presented wide bands in the visible region that were associated with the internal transitions of the dopants. All the samples presented photoluminescent bands near 420 nm, 496 nm and 591 nm, with different relative intensities that yield characteristic luminescence colors ranging from blue to red. - Graphical abstract: Phosphorescence of cadmium silicate doped with transition metals: nature of defects and possible luminescent channels. Highlights: ? CdSiO{sub 3} was doped with Mn, Ni and Cr to produce multicolored phosphors. ? Valence of the dopants was determined as 3+ for Cr, 2+ for Ni and 2+ and 3+ for Mn. ? The presence of absorption bands in the visible region led to self-absorption. ? Self-absorption in some cases can decrease the light output. ? Luminescent channels were created and related to internal transitions of the dopants.

  14. Catalytic hydrocarbon reactions over supported metal oxides. Progress report, April 1, 1994--January 31, 1995

    SciTech Connect (OSTI)

    Ekerdt, J.G.

    1995-01-31T23:59:59.000Z

    Oxide catalysis plays a central role in hydrocarbon processing and improvements in catalytic activity or selectivity are of great technological importance because these improvements will translate directly into more efficient utilization of hydrocarbon supplies and lower energy consumption in separation processes. An understanding of the relationships between surface structure and catalytic properties is needed to describe and improve oxide catalysts. Our approach has been to prepare supported oxides that have a specific structure and oxidation state and then employ these structures in reaction studies. Our current research program is focused on studying the fundamental relationships between structure and reactivity for two important reactions that are present in many oxide-catalyzed processes, partial oxidation and carbon-carbon bond formation. Oxide catalysis can be a complex process with both metal cation and oxygen anions participating in the chemical reactions. From an energy perspective carbon-carbon bond formation is particularly relevant to CO hydrogenation in isosynthesis. Hydrogenolysis and hydrogenation form the basis for heteroatom removal in fuels processing. Understanding the catalysis of these processes (and others) requires isolating reaction steps in the overall cycle and determining how structure and composition influence the individual reaction steps. Specially designed oxides, such as we use, permit one to study some of the steps in oxidation, carbon-carbon coupling and heteroatom removal catalysis. During the course of our studies we have: (1) developed methods to form and stabilize various Mo and W oxide structures on silica; (2) studied C-H abstraction reactions over the fully oxidized cations; (3) studied C-C bond coupling by methathesis and reductive coupling of aldehydes and ketones over reduced cation structures; and (4) initiated a study of hydrogenation and hydrogenolysis over reduced cation structures.

  15. Comprehensive study of the metal-insulator transition in pulsed laser deposited epitaxial VO2 thin films

    E-Print Network [OSTI]

    Wu, Junqiao

    the optical and infrared reflection spectra in the metallic phase, we obtained the plasma edge of VO2, from studied most intensively owing mostly to its near-room-temperature phase transition as well as its high

  16. Interaction of Pu(IV,VI) hydroxides/oxides with metal hydroxides/oxides in alkaline media

    SciTech Connect (OSTI)

    Fedoseev, A.M.; Krot, N.N.; Budantseva, N.A.; Bessonov, A.A.; Nikonov, M.V.; Grigoriev, M.S.; Garnov, A.Y.; Perminov, V.P.; Astafurova, L.N. [Russian Academy of Sciences, Moscow (Russian Federation). Inst. of Physical Chemistry

    1998-08-01T23:59:59.000Z

    The primary goal of this investigation was to obtain data on the possibility, extent, and characteristics of interaction of Pu(IV) and (VI) with hydroxides and oxides of d-elements and other metals [Al(III), LA(III), and U(VI)] in alkaline media. Such information is important in fundamental understanding of plutonium disposition and behavior in Hanford Site radioactive tank waste sludge. These results supply essential data for determining criticality safety and in understanding transuranic waste behavior in storage, retrieval, and treatment of Hanford Site tank waste.

  17. Atmosphere, Interior, and Evolution of the Metal-Rich Transiting Planet HD 149026b

    E-Print Network [OSTI]

    J. J. Fortney; D. Saumon; M. S. Marley; K. Lodders; R. S. Freedman

    2006-01-03T23:59:59.000Z

    We investigate the atmosphere and interior of the new transiting planet HD 149026b, which appears to be very rich in heavy elements. We first compute model atmospheres at metallicities ranging from solar to ten times solar, and show how for cases with high metallicity or inefficient redistribution of energy from the day side, the planet may develop a hot stratosphere due to absorption of stellar flux by TiO and VO. The spectra predicted by these models are very different than cooler atmosphere models without stratospheres. The spectral effects are potentially detectable with the Spitzer Space Telescope. In addition the models with hot stratospheres lead to a large limb brightening, rather than darkening. We compare the atmosphere of HD 149026b to other well-known transiting planets, including the recently discovered HD 189733b, which we show have planet-to-star flux ratios twice that of HD 209458 and TrES-1. The methane abundance in the atmosphere of HD 189733b is a sensitive indicator of atmospheric temperature and metallicity and can be constrained with Spitzer IRAC observations. We then turn to interior studies of HD 149026b and use a grid of self-consistent model atmospheres and high-pressure equations of state for all components to compute thermal evolution models of the planet. We estimate that the mass of heavy elements within the planet is in the range of 60 to 93 M_earth. Finally, we discuss trends in the radii of transiting planets with metallicity in light of this new member of the class.

  18. Metal-Insulator Transition Revisited for Cold Atoms in Non-Abelian Gauge Potentials

    E-Print Network [OSTI]

    Indubala I. Satija; Daniel C. Dakin; Charles W. Clark

    2006-07-10T23:59:59.000Z

    We discuss the possibility of realizing metal-insulator transitions with ultracold atoms in two-dimensional optical lattices in the presence of artificial gauge potentials. Such transitions have been extensively studied for magnetic fields corresponding to Abelian gauges; they occur when the magnetic flux penetrating the lattice plaquette is an irrational multiple of the magnetic flux quantum. Here we present the first study of these transitions for non-Abelian U(2) gauge fields, which can be realized with atoms with two pairs of degenerate internal states. In contrast to the Abelian case, the spectrum and localization transition in the non-Abelian case is strongly influenced by atomic momenta. In addition to determining the localization boundary, the momentum fragments the spectrum and the minimum energy viewed as a function of momentum exhibits a step structure. Other key characteristics of the non-Abelian case include the absence of localization for certain states and satellite fringes around the Bragg peaks in the momentum distribution and an interesting possibility that the transition can be tuned by the atomic momenta.

  19. Secondary cell with orthorhombic alkali metal/manganese oxide phase active cathode material

    DOE Patents [OSTI]

    Doeff, M.M.; Peng, M.Y.; Ma, Y.; Visco, S.J.; DeJonghe, L.C.

    1996-09-24T23:59:59.000Z

    An alkali metal manganese oxide secondary cell is disclosed which can provide a high rate of discharge, good cycling capabilities, good stability of the cathode material, high specific energy (energy per unit of weight) and high energy density (energy per unit volume). The active material in the anode is an alkali metal and the active material in the cathode comprises an orthorhombic alkali metal manganese oxide which undergoes intercalation and deintercalation without a change in phase, resulting in a substantially linear change in voltage with change in the state of charge of the cell. The active material in the cathode is an orthorhombic structure having the formula M{sub x}Z{sub y}Mn{sub (1{minus}y)}O{sub 2}, where M is an alkali metal; Z is a metal capable of substituting for manganese in the orthorhombic structure such as iron, cobalt or titanium; x ranges from about 0.2 in the fully charged state to about 0.75 in the fully discharged state, and y ranges from 0 to 60 atomic %. Preferably, the cell is constructed with a solid electrolyte, but a liquid or gelatinous electrolyte may also be used in the cell. 11 figs.

  20. Secondary cell with orthorhombic alkali metal/manganese oxide phase active cathode material

    DOE Patents [OSTI]

    Doeff, Marca M. (Hayward, CA); Peng, Marcus Y. (Cupertino, CA); Ma, Yanping (Albany, CA); Visco, Steven J. (Berkeley, CA); DeJonghe, Lutgard C. (Lafayette, CA)

    1996-01-01T23:59:59.000Z

    An alkali metal manganese oxide secondary cell is disclosed which can provide a high rate of discharge, good cycling capabilities, good stability of the cathode material, high specific energy (energy per unit of weight) and high energy density (energy per unit volume). The active material in the anode is an alkali metal and the active material in the cathode comprises an orthorhombic alkali metal manganese oxide which undergoes intercalation and deintercalation without a change in phase, resulting in a substantially linear change in voltage with change in the state of charge of the cell. The active material in the cathode is an orthorhombic structure having the formula M.sub.x Z.sub.y Mn.sub.(1-y) O.sub.2, where M is an alkali metal; Z is a metal capable of substituting for manganese in the orthorhombic structure such as iron, cobalt or titanium; x ranges from about 0.2 in the fully charged state to about 0.75 in the fully discharged state, and y ranges from 0 to 60 atomic %. Preferably, the cell is constructed with a solid electrolyte, but a liquid or gelatinous electrolyte may also be used in the cell.

  1. Metal oxide coating of carbon supports for supercapacitor applications.

    SciTech Connect (OSTI)

    Boyle, Timothy J.; Tribby, Louis, J (University of New Mexico, Albuquerque, NM); Lakeman, Charles D. E. (TPL, Inc., Albuquerque, NM); Han, Sang M. (University of New Mexico, Albuquerque, NM); Lambert, Timothy N.; Fleig, Patrick F. (TPL, Inc., Albuquerque, NM)

    2008-07-01T23:59:59.000Z

    The global market for wireless sensor networks in 2010 will be valued close to $10 B, or 200 M units. TPL, Inc. is a small Albuquerque based business that has positioned itself to be a leader in providing uninterruptible power supplies in this growing market with projected revenues expected to exceed $26 M in 5 years. This project focused on improving TPL, Inc.'s patent-pending EnerPak{trademark} device which converts small amounts of energy from the environment (e.g., vibrations, light or temperature differences) into electrical energy that can be used to charge small energy storage devices. A critical component of the EnerPak{trademark} is the supercapacitor that handles high power delivery for wireless communications; however, optimization and miniaturization of this critical component is required. This proposal aimed to produce prototype microsupercapacitors through the integration of novel materials and fabrication processes developed at New Mexico Technology Research Collaborative (NMTRC) member institutions. In particular, we focused on developing novel ruthenium oxide nanomaterials and placed them into carbon supports to significantly increase the energy density of the supercapacitor. These improvements were expected to reduce maintenance costs and expand the utility of the TPL, Inc.'s device, enabling New Mexico to become the leader in the growing global wireless power supply market. By dominating this niche, new customers were expected to be attracted to TPL, Inc. yielding new technical opportunities and increased job opportunities for New Mexico.

  2. Probing Reaction Dynamics of Transition-Metal Complexes in Solution via Time-Resolved Soft X-ray Spectroscopy

    SciTech Connect (OSTI)

    Huse, Nils; Kim, Tae Kyu; Khalil, Munira; Jamula, Lindsey; McCusker, James K.; Schoenlein, Robert W.

    2010-05-02T23:59:59.000Z

    We report the first time-resolved soft x-ray measurements of solvated transition-metal complexes. L-edge spectroscopy directly probes dynamic changes in ligand-field splitting of 3d orbitals associated with the spin transition, and mediated by changes in ligand-bonding.

  3. Electrophoretic-like Gating Used To Control Metal-Insulator Transitions in Electronically Phase Separated Manganite Wires

    E-Print Network [OSTI]

    Tennessee, University of

    traditional carrier doping and by inducing electroresistive phase transitions in the material. In the case, and an electric field applied to the gate acts to change the material's access to electrons. This switchingElectrophoretic-like Gating Used To Control Metal-Insulator Transitions in Electronically Phase

  4. Ionic hydrogenations of hindered olefins at low temperature. Hydride transfer reactions of transition metal hydrides

    SciTech Connect (OSTI)

    Bullock, R.M.; Song, J.S. (Brookhaven National Lab., Upton, NY (United States))

    1994-09-21T23:59:59.000Z

    Sterically hindered olefins can be hydrogenated at -50[degree]C in dichloromethane using triflic acid (CF[sub 3]SO[sub 3]H) and a hydride donor. Mechanistic studies indicate that these reactions proceed by hydride transfer to the carbenium ion that is formed by protonation of the olefin. Olefins that form tertiary carbenium ions upon protonation are hydrogenated in high yields (90-100%). Styrenes generally produce lower yields of hydrogenated products (50-60%). Suitable hydride donors include HSiE[sub 3] and several transition metal carbonyl hydrides HW(CO)[sub 3]Cp, HW(CO)[sub 3]Cp[sup +], HMo-(CO)[sub 3]Cp, HMn(CO)[sub 5], HRe(CO)[sub 3], and HO[sub 3](CO)[sub 1]Cp*; Cp = [eta][sup 5]-C[sub 3]H[sub 5+], Cp* = [eta][sup 5]-C[sub 5]Me[sub 5]. A characteristic that is required for transition metal hydrides to be effective is that the cationic dihydrides (or dihydrogen complexes) that result from their protonation must have sufficient acidity to transfer a proton to the olefin, as well as sufficient thermal stability to avoid significant decomposition on the time scale of the hydrogenation reaction. Metal hydrides that fall due to insufficient stability of their protonated forms include HMo(CO)[sub 2](PPH[sub 3])Cp, HMo(CO)[sub 3]Cp*, and HFe(CO)[sub 2]Cp*. 62 refs., 2 tabs.

  5. Final Report: Catalytic Hydrocarbon Reactions over Supported Metal Oxides, August 1, 1995 - July 31, 1999

    SciTech Connect (OSTI)

    Ekerdt, John G.

    1999-07-31T23:59:59.000Z

    The research program focused on the catalysis of hydrodesulfurization (HDS) over molybdenum-based catalysts and how catalyst composition, redox ability, structure and neighboring sites control the catalytic properties of metal oxides. We sought to understand the catalytic features/sites that control hydrogenation, hydrogenolysis, and isomerization during HDS. Unprompted silica-supported molybdenum oxides and molybdenum sulfides were studied. Model catalyst systems were prepared from organometallic precursors or cluster compounds to generate supported structures that feature Mo(II) and Mo(IV) cations that are isolated or in ensembles and that have either Mo-O or Mo-S bonds. Conventional MOS{sub 2} catalysts, which contain both edge and rim sites, were be studied. Finally, single-layer MOS{sub 2} structures were also prepared from 2H-MoS{sub 2} powder so that the model systems could be compared against a disulfide catalyst that only involves rim sites. Catalytic reactions for thiophene and tetrahydrothione were studied over the various catalysts. Oxidation states were determined using X-ray photoelectron spectroscopy. X-ray crystallography was used to characterize and follow changes in the MOS{sub 2} structures. The program on metal oxides prepared supported oxides that have a specific structure and oxidation state to serve as model templates for the more complex commercial catalysts and then employed these structures in reaction studies. This focus area examined the relationships between structure and cation redox characteristics in oxidation catalysis. Infrared and Raman spectroscopy were used to characterize the cations and reaction intermediates.

  6. Tubular solid oxide fuel cells with porous metal supports and ceramic interconnections

    DOE Patents [OSTI]

    Huang, Kevin (Export, PA); Ruka, Roswell J. (Pittsburgh, PA)

    2012-05-08T23:59:59.000Z

    An intermediate temperature solid oxide fuel cell structure capable of operating at from 600.degree. C. to 800.degree. C. having a very thin porous hollow elongated metallic support tube having a thickness from 0.10 mm to 1.0 mm, preferably 0.10 mm to 0.35 mm, a porosity of from 25 vol. % to 50 vol. % and a tensile strength from 700 GPa to 900 GPa, which metallic tube supports a reduced thickness air electrode having a thickness from 0.010 mm to 0.2 mm, a solid oxide electrolyte, a cermet fuel electrode, a ceramic interconnection and an electrically conductive cell to cell contact layer.

  7. Composite materials with metal oxide attached to lead chalcogenide nanocrystal quantum dots with linkers

    DOE Patents [OSTI]

    Fuke, Nobuhiro; Koposov, Alexey Y; Sykora, Milan; Hoch, Laura

    2014-12-16T23:59:59.000Z

    Composite materials useful for devices such as photoelectrochemical solar cells include a substrate, a metal oxide film on the substrate, nanocrystalline quantum dots (NQDs) of lead sulfide, lead selenide, and lead telluride, and linkers that attach the NQDs to the metal oxide film. Suitable linkers preserve the 1s absorption peak of the NQDs. A suitable linker has a general structure A-B-C where A is a chemical group adapted for binding to a MO.sub.x and C is a chemical group adapted for binding to a NQD and B is a divalent, rigid, or semi-rigid organic spacer moiety. Other linkers that preserve the 1s absorption peak may also be used.

  8. VOLUME 86, NUMBER 23 P H Y S I C A L R E V I E W L E T T E R S 4 JUNE 2001 Light-Induced Metal-Insulator Transition in a Switchable Mirror

    E-Print Network [OSTI]

    Wijngaarden, Rinke J.

    possibility to tune yttrium hydride through the T 0 metal-insulator transition. Conductivity and Hall

  9. Synthesis of Low-Melting Metal Oxide and Sulfide Nanowires and Nanobelts

    E-Print Network [OSTI]

    Daraio, Chiara

    such as oxygen/hydrogen mixture for oxides and H2S for sulfides. In the case of b-Ga2O3 and SnO2, a change with the sulfide nanowires suggest that H2S reacts directly at the molten metal surface to form gallium sulfide to either oxygen or H2S at an elevated temperature. EXPERIMENTAL The synthesis of the nanowires

  10. Investigation of zinc oxide doped with metal impurities for use as thin film conductive phosphors

    E-Print Network [OSTI]

    Evatt, Steven R.

    1994-01-01T23:59:59.000Z

    . Illustration of planar field emission diode developed by Weichold et al. . . . . . 48 Fig. 29. I-V data from vacuum field emission light emitting diode structure, after Williams, 1994. . . . . . . . . . 49 Fig. 30. Illustration of the oxidized porous silicon... carriers into a forward biased p-n junction will result in light emission if radiative transitions take place [3]. These semiconductors find applications in light emitting diodes. Other phosphors will produce light emission when they are placed...

  11. Interplay between Ferroelastic and Metal-Insulator Phase Transitions in Strained Quasi-2D VO[subscript 2] Nanoplatelets

    SciTech Connect (OSTI)

    Tselev, Alexander; Strelcov, Evgheni; Luk’ yanchuk, Igor A.; Budai, John D.; Tischler, Jonathan Z.; Ivanov, Ilia N.; Jones, Keith; Proksch, Roger; Kalinin, Sergei V.; Kolmakov, Andrei (Asylum); (ORNL); (SIUC); (UPJV)

    2011-08-09T23:59:59.000Z

    Formation of ferroelastic twin domains in vanadium dioxide (VO{sub 2}) nanosystems can strongly affect local strain distributions, and hence couple to the strain-controlled metal-insulator transition. Here we report polarized-light optical and scanning microwave microscopy studies of interrelated ferroelastic and metal-insulator transitions in single-crystalline VO{sub 2} quasi-two-dimensional (quasi-2D) nanoplatelets (NPls). In contrast to quasi-1D single-crystalline nanobeams, the 2D geometric frustration results in emergence of several possible families of ferroelastic domains in NPls, thus allowing systematic studies of strain-controlled transitions in the presence of geometrical frustration. We demonstrate the possibility of controlling the ferroelastic domain population by the strength of the NPl-substrate interaction, mechanical stress, and by the NPl lateral size. Ferroelastic domain species and domain walls are identified based on standard group-theoretical considerations. Using variable temperature microscopy, we imaged the development of domains of metallic and semiconducting phases during the metal-insulator phase transition and nontrivial strain-driven reentrant domain formation. A long-range reconstruction of ferroelastic structures accommodating metal-insulator domain formation has been observed. These studies illustrate that a complete picture of the phase transitions in single-crystalline and disordered VO{sub 2} structures can be drawn only if both ferroelastic and metal-insulator strain effects are taken into consideration and understood.

  12. Oxidation Resistant, Cr Retaining, Electrically Conductive Coatings on Metallic Alloys for SOFC Interconnects

    SciTech Connect (OSTI)

    Vladimir Gorokhovsky

    2008-03-31T23:59:59.000Z

    This report describes significant results from an on-going, collaborative effort to enable the use of inexpensive metallic alloys as interconnects in planar solid oxide fuel cells (SOFCs) through the use of advanced coating technologies. Arcomac Surface Engineering, LLC, under the leadership of Dr. Vladimir Gorokhovsky, is investigating filtered-arc and filtered-arc plasma-assisted hybrid coating deposition technologies to promote oxidation resistance, eliminate Cr volatility, and stabilize the electrical conductivity of both standard and specialty steel alloys of interest for SOFC metallic interconnect (IC) applications. Arcomac has successfully developed technologies and processes to deposit coatings with excellent adhesion, which have demonstrated a substantial increase in high temperature oxidation resistance, stabilization of low Area Specific Resistance values and significantly decrease Cr volatility. An extensive matrix of deposition processes, coating compositions and architectures was evaluated. Technical performance of coated and uncoated sample coupons during exposures to SOFC interconnect-relevant conditions is discussed, and promising future directions are considered. Cost analyses have been prepared based on assessment of plasma processing parameters, which demonstrate the feasibility of the proposed surface engineering process for SOFC metallic IC applications.

  13. Phase transition and metallization of FeO at high pressures and temperatures

    SciTech Connect (OSTI)

    Fischer, Rebecca A.; Campbell, Andrew J.; Lord, Oliver T.; Shofner, Gregory A.; Dera, Przemyslaw; Prakapenka, Vitali B. (Maryland); (UC); (UCL)

    2012-05-10T23:59:59.000Z

    Wuestite, Fe{sub 1-x}O, is an important component in the mineralogy of Earth's lower mantle and may also be a component of the core. Therefore its high pressure-temperature behavior, including its electronic structure, is essential to understanding the nature and evolution of Earth's deep interior. We performed X-ray diffraction and radiometric measurements on wuestite in a laser-heated diamond anvil cell, finding an insulator-metal transition at high pressures and temperatures. Our data show a negative slope for this apparently isostructural phase boundary, which is characterized by a volume decrease and emissivity increase. The metallic phase of FeO is stable at conditions of the lower mantle and core, which has implications for the high P-T character of Fe-O bonds, magnetic field propagation, and lower mantle conductivity.

  14. Synthesis of organometallic complexes containing Group 13 elements and transition metals

    SciTech Connect (OSTI)

    Kong, G.

    1993-01-01T23:59:59.000Z

    New organometallic complexes containing Group 13 elements and transition metals were synthesized characterized by X-ray diffraction methods. (C[sub 5]H[sub 5])[sub 2]W[l brace]In(CH[sub 3])[sub 2][r brace][sub 2], (C[sub 5]H[sub 5])[sub 2]Mo[l brace]In(CH[sub 3])[sub 2][r brace][sub 2], and (C[sub 5]H[sub 5])[sub 2]W(I)[l brace]In(CH[sub 3])[sub 2][r brace] were synthesized by alkane elimination reactions between trimethylindium and metal hydride complexes (C[sub 5]H[sub 5])[sub 2]MH[sub 2] (M = W, Mo). [K]-[In[l brace]Fe[sub 2] (CO[sub 8])[r brace][sub 2

  15. Electronic Structure of Transition Metal-Cysteine Complexes From X-Ray Absorption Spectroscopy

    SciTech Connect (OSTI)

    Leung, B.O.; Jalilehvand, F.; Szilagyi, R.K.

    2009-05-19T23:59:59.000Z

    The electronic structures of Hg{sup II}, Ni{sup II}, Cr{sup III}, and Mo{sup V} complexes with cysteine were investigated by sulfur K-edge X-ray absorption near-edge structure (XANES) spectroscopy and density functional theory. The covalency in the metal-sulfur bond was determined by analyzing the intensities of the electric-dipole allowed pre-edge features appearing in the XANES spectra below the ionization threshold. Because of the well-defined structures of the selected cysteine complexes, the current work provides a reference set for further sulfur K-edge XAS studies of bioinorganic active sites with transition metal-sulfur bonds from cysteine residues as well as more complex coordination compounds with thiolate ligands.

  16. Steam reforming on transition-metal carbides from density-functional theory

    E-Print Network [OSTI]

    Vojvodic, Aleksandra

    2009-01-01T23:59:59.000Z

    A screening study of the steam reforming reaction (CH_4 + H_2O -> CO + 3H_2) on early transition-metal carbides (TMC's) is performed by means of density-functional theory calculations. The set of considered surfaces includes the alpha-Mo_2C(100) surfaces, the low-index (111) and (100) surfaces of TiC, VC, and delta-MoC, and the oxygenated alpha-Mo_2C(100) and TMC(111) surfaces. It is found that carbides provide a wide spectrum of reactivities towards the steam reforming reaction, from too reactive via suitable to too inert. The reactivity is discussed in terms of the electronic structure of the clean surfaces. Two surfaces, the delta-MoC(100) and the oxygen passivated alpha-Mo_2C(100) surfaces, are identified as promising steam reforming catalysts. These findings suggest that carbides provide a playground for reactivity tuning, comparable to the one for pure metals.

  17. Electrically induced insulator to metal transition in epitaxial SmNiO{sub 3} thin films

    SciTech Connect (OSTI)

    Shukla, Nikhil, E-mail: nss152@psu.edu; Dasgupta, Sandeepan; Datta, Suman [Department of Electrical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Joshi, Toyanath; Borisov, Pavel; Lederman, David [Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia 26506-6315 (United States)

    2014-07-07T23:59:59.000Z

    We report on the electrically induced insulator to metal transition (IMT) in SmNiO{sub 3} thin films grown on (001) LaAlO{sub 3} by pulsed laser deposition. The behavior of the resistivity as a function of temperature suggests that the primary transport mechanism in the SmNiO{sub 3} insulating state is dominated by Efros-Shklovskii variable range hopping (ES-VRH). Additionally, the magnetic transition in the insulating state of SmNiO{sub 3} modifies the characteristics of the ES-VRH transport. Systematic DC and pulsed current-voltage measurements indicate that current-induced joule heating is the fundamental mechanism driving the electrically induced IMT in SmNiO{sub 3}. These transport properties are explained in context of the IMT in SmNiO{sub 3} being related to the strong electron-lattice coupling.

  18. Thin films of metal oxide nanoparticles deposited on substrates find applications in various technologies such as sensors, heterogeneous

    E-Print Network [OSTI]

    oven, which restrict the choice of substrates (metal, glass) and can negatively affects their performances (stress induction, oxidation, substrate warping). VALUE PROPOSITION This novel process offers key+ hours in traditional ovens (including ramp up & down) Delivers equal or superior optoelectronic

  19. An Atomic Perspective of a Doped Metal-Oxide Interface, E. A. A. Jarvis and E. A. Carter*

    E-Print Network [OSTI]

    Carter, Emily A.

    An Atomic Perspective of a Doped Metal-Oxide Interface, E. A. A. Jarvis and E. A. Carter interactions. The past two decades marked an explosion of experimental and theoretical advances in treating gas

  20. Low contact resistivity of metals on nitrogen-doped cuprous oxide (Cu 2O) thin-films

    E-Print Network [OSTI]

    Siah, Sin Cheng

    Forming low-resistivity contacts on cuprous oxide (Cu[subscript 2]O) is an essential step toward demonstrating its suitability as a candidate solar cell material. We measure the contact resistivity of three noble metals ...

  1. Modelling of thermo-mechanical and irradiation behavior of metallic and oxide fuels for sodium fast reactors

    E-Print Network [OSTI]

    Karahan, Aydin

    2009-01-01T23:59:59.000Z

    A robust and reliable code to model the irradiation behavior of metal and oxide fuels in sodium cooled fast reactors is developed. Modeling capability was enhanced by adopting a non-empirical mechanistic approach to the ...

  2. Study of intermediates from transition metal excited-state electron-transfer reactions

    SciTech Connect (OSTI)

    Hoffman, M.Z.

    1992-07-31T23:59:59.000Z

    Conventional and fast-kinetics techniques of photochemistry, photophysics, radiation chemistry, and electrochemistry were used to study the intermediates involved in transition metal excited-state electron-transfer reactions. These intermediates were excited state of Ru(II) and Cr(III) photosensitizers, their reduced forms, and species formed in reactions of redox quenchers and electron-transfer agents. Of particular concern was the back electron-transfer reaction between the geminate pair formed in the redox quenching of the photosensitizers, and the dependence of its rate on solution medium and temperature in competition with transformation and cage escape processes. (DLC)

  3. Effect of electron collecting metal oxide layer in normal and inverted structure polymer solar cells

    SciTech Connect (OSTI)

    Ng, A.; Liu, X.; Sun, Y. C.; Djuriši?, A. B. [Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. (China); Ng, A. M. C. [Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China and Nanostructure Institute for Energy and Environmental Research, Division of Physical Sciences, South University of Science and Technology of China, Shenzhen (China); Chan, W. K. [Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. (China)

    2013-12-04T23:59:59.000Z

    We performed a systematic study of the effect of electron collecting metal oxide layer on the performance of P3HT: PCBM solar cells. Zinc oxide (ZnO) or titanium dioxide (TiO{sub 2}) buffer layers were prepared by either e-beam evaporation or solution processing method. We also compared the photovoltaic performance of inserting the buffer layer between indium tin oxide (ITO) and the polymer layer for the inverted structure (ITO/ ZnO or TiO{sub 2}/P3HT:PCBM/V{sub 2}O{sub 5}/Au) as well as inserting the buffers layers between the polymer and the aluminum electrode for the conventional structure (ITO/V{sub 2}O{sub 5}/P3HT:PCBM/ZnO or TiO{sub 2}/Al). The results are shown in detail.

  4. Protective coating on positive lithium-metal-oxide electrodes for lithium batteries

    DOE Patents [OSTI]

    Johnson, Christopher S.; Thackeray, Michael M.; Kahaian, Arthur J.

    2006-05-23T23:59:59.000Z

    A positive electrode for a non-aqueous lithium cell comprising a LiMn2-xMxO4 spinel structure in which M is one or more metal cations with an atomic number less than 52, such that the average oxidation state of the manganese ions is equal to or greater than 3.5, and in which 0.ltoreq.x.ltoreq.0.15, having one or more lithium spine oxide LiM'2O4 or lithiated spinel oxide Li1+yM'2O4 compounds on the surface thereof in which M' are cobalt cations and in which 0.ltoreq.y.ltoreq.1.

  5. Evaluation of the thermodynamic properties of hydrated metal oxide nanoparticles by INS techniques

    SciTech Connect (OSTI)

    Spencer, Elinor [Virginia Polytechnic Institute and State University] [Virginia Polytechnic Institute and State University; Ross, Dr. Nancy [Virginia Polytechnic Institute and State University] [Virginia Polytechnic Institute and State University; Parker, Stewart F. [ISIS Facility, Rutherford Appleton Laboratory (ISIS)] [ISIS Facility, Rutherford Appleton Laboratory (ISIS); Kolesnikov, Alexander I [ORNL] [ORNL

    2013-01-01T23:59:59.000Z

    In this contribution we will present a detailed methodology for the elucidation of the following aspects of the thermodynamic properties of hydrated metal oxide nanoparticles from high-resolution, low-temperature inelastic neutron scattering (INS) data: (i) the isochoric heat capacity and entropy of the hydration layers both chemi- and physisorbed to the particle surface; (ii) the magnetic contribution to the heat capacity of the nanoparticles. This will include the calculation of the vibrational density of states (VDOS) from the raw INS spectra, and the subsequent extraction of the thermodynamic data from the VDOS. This technique will be described in terms of a worked example namely, cobalt oxide (Co3O4 and CoO). To complement this evaluation of the physical properties of metal oxide nanoparticle systems, we will emphasise the importance of high-resolution, high-energy INS for the determination of the structure and dynamics of the water species, namely molecular (H2O) and dissociated water (OH, hydroxyl), confined to the oxide surfaces. For this component of the chapter we will focus on INS investigations of hydrated isostructural rutile (a-TiO2) and cassiterite (SnO2) nanoparticles. We will complete this discussion of nanoparticle analysis by including an appraisal of the INS instrumentation employed in such studies with particular focus on TOSCA [ISIS, Rutherford Appleton Laboratory (RAL), U.K.] and the newly developed spectrometer SEQUOIA [SNS, Oak Ridge National Laboratory (ORNL), U.S.A].

  6. The influence of transition metal solutes on dislocation core structure and values of Peierls stress and barrier in tungsten.

    SciTech Connect (OSTI)

    Samolyuk, German D [ORNL; Stoller, Roger E [ORNL; Osetskiy, Yury N [ORNL

    2013-01-01T23:59:59.000Z

    Several transition metals were examined to evaluate their potential for improving the ductility of tungsten. We investigate the dislocation core structure, Peierls stress and barrier of $1/2\\langle111\\rangle$ screw dislocations in binary tungsten-transition metal alloys (W$_{1-x}$TM$_{x}$) based on first principles electronic structure calculations. The periodic quadrupole approach was applied to model the structure of $1/2\\langle111\\rangle$ dislocation. The alloying with transition metals was modeled using the virtual crystal approximation. In order to verify the applicability of this approach, the equilibrium lattice parameter and elastic constants were calculated for tungsten alloyed with the set of transition metals. Reasonable agreement was obtained between results using the virtual crystal approximation and those using both a conventional super-cell approach and existing experimental data. Increasing the concentration of a transition metal from the VIIIA group leads to reduction of the $C^\\prime$ elastic constant and increase of elastic anisotropy A=$C_{44}/C^\\prime$. It was demonstrated that alloying W with a group VIIIA transition metal changes the structure of the dislocation core from symmetric to asymmetric, similar to results obtained for W$_{1-x}$Re$_{x}$ alloys in the earlier work of Romaner {\\it et al} (Phys. Rev. Lett. 104, 195503 (2010)). Following the core symmetry change, the values of the Peierls stress and barrier are reduced. This combination of two effects could lead to increased ductility in a tungsten-based alloy\\comments. Our results demonstrate that similar effects could be achieved with any of the transition metals from the VIIIA group.

  7. Rare-earth transition-metal intermetallics: Structure-bonding-property relationships

    SciTech Connect (OSTI)

    Han, M.K.

    2006-05-06T23:59:59.000Z

    The explorations of rare-earth, transition metal intermetallics have resulted in the synthesis and characterization, and electronic structure investigation, as well as understanding the structure-bonding property relationships. The work has presented the following results: (1) Understanding the relationship between compositions and properties in LaFe{sub 13-x}Si{sub x} system: A detailed structural and theoretical investigation provided the understanding of the role of a third element on stabilizing the structure and controlling the transformation of cubic NaZn{sub 13}-type structures to the tetragonal derivative, as well as the relationship between the structures and properties. (2) Synthesis of new ternary rare-earth iron silicides Re{sub 2-x}Fe{sub 4}Si{sub 14-y} and proposed superstructure: This compound offers complex structural challenges such as fractional occupancies and their ordering in superstructure. (3) Electronic structure calculation of FeSi{sub 2}: This shows that the metal-semiconductor phase transition depends on the structure. The mechanism of band gap opening is described in terms of bonding and structural distortion. This result shows that the electronic structure calculations are an essential tool for understanding the relationship between structure and chemical bonding in these compounds. (4) Synthesis of new ternary rare-earth Zinc aluminides Tb{sub 3}Zn{sub 3.6}Al{sub 7.4}: Partially ordered structure of Tb{sub 3}Zn{sub 3.6}Al{sub 7.4} compound provides new insights into the formation, composition and structure of rare-earth transition-metal intermetallics. Electronic structure calculations attribute the observed composition to optimizing metal-metal bonding in the electronegative (Zn, Al) framework, while the specific ordering is strongly influenced by specific orbital interactions. (5) Synthesis of new structure type of Zn{sub 39}(Cr{sub x}Al{sub 1-x}){sub 81}: These layered structures are similar to icosahedral Mn-Al quasicrystalline compounds. Therefore, this compound may provide new insights into the formation, composition and structure of quasicrystalline materials.

  8. Rare-Earth Transition-Metal Intermetallics: Structure-bonding-Property Relationships

    SciTech Connect (OSTI)

    Mi-Kyung Han

    2006-05-01T23:59:59.000Z

    Our explorations of rare-earth, transition metal intermetallics have resulted in the synthesis and characterization, and electronic structure investigation, as well as understanding the structure-bonding-property relationships. Our work has presented the following results: (1) Understanding the relationship between compositions and properties in LaFe{sub 13-x}Si{sub x} system: A detailed structural and theoretical investigation provided the understanding of the role of a third element on stabilizing the structure and controlling the transformation of cubic NaZn{sub 13}-type structures to the tetragonal derivative, as well as the relationship between the structures and properties. (2) Synthesis of new ternary rare-earth iron silicides RE{sub 2-x}Fe{sub 4}Si{sub 14-y} and proposed superstructure: This compound offers complex structural challenges such as fractional occupancies and their ordering in superstructure. (3) Electronic structure calculation of FeSi{sub 2}: This shows that the metal-semiconductor phase transition depends on the structure. The mechanism of band gap opening is described in terms of bonding and structural distortion. This result shows that the electronic structure calculations are an essential tool for understanding the relationship between structure and chemical bonding in these compounds. (4) Synthesis of new ternary rare-earth Zinc aluminides Tb{sub 3}Zn{sub 3.6}Al{sub 7.4}: Partially ordered structure of Tb{sub 3}Zn{sub 3.6}Al{sub 7.4} compound provides new insights into the formation, composition and structure of rare-earth transition-metal intermetallics. Electronic structure calculations attribute the observed composition to optimizing metal-metal bonding in the electronegative (Zn, Al) framework, while the specific ordering is strongly influenced by specific orbital interactions. (5) Synthesis of new structure type of Zn{sub 39}(Cr{sub x}Al{sub 1-x}){sub 81}: These layered structures are similar to icosahedral Mn-Al quasicrystalline compounds. Therefore, this compound may provide new insights into the formation, composition and structure of quasicrystalline materials.

  9. Respiration of metal (hydr)oxides by Shewanella and Geobacter: a key role for multihaem c-type cytochromes

    SciTech Connect (OSTI)

    Shi, Liang; Squier, Thomas C.; Zachara, John M.; Fredrickson, Jim K.

    2007-07-01T23:59:59.000Z

    Dissimilatory reduction of metal (e.g. Fe, Mn) (hydr)oxides represents a challenge for microorganisms, as their cell envelopes are impermeable to metal (hydr)oxides that are poorly soluble in water. To overcome this physical barrier, the Gram-negative bacteria Shewanella oneidensis MR-1 and Geobactersulfurreducens have developed electron transfer (ET) strategies that require multihaem c-type cytochromes (c-Cyts). In S. oneidensis MR-1, multihaem c-Cyts CymA and MtrA are believed to transfer electrons from the inner membrane quinone/quinol pool through the periplasm to the outer membrane. The type II secretion system of S. oneidensis MR-1 has been implicated in the reduction of metal (hydr)oxides, most likely by translocating decahaem c-Cyts MtrC and OmcA across outer membrane to the surface of bacterial cells where they form a protein complex. The extracellular MtrC and OmcA can directly reduce solid metal (hydr)oxides. Likewise, outer membrane multihaem c-Cyts OmcE and OmcS of G. sulfurreducens are suggested to transfer electrons from outer membrane to type IV pili that are hypothesized to relay the electrons to solid metal (hydr)oxides. Thus, multihaem c-Cyts play critical roles in S. oneidensis MR-1-and G. sulfurreducens-mediated dissimilatory reduction of solid metal (hydr)oxides by facilitating ET across the bacterial cell envelope.

  10. Thermodynamics of the ferromagnetic phase transition in nearly half metallic CoS2 at high pressures

    SciTech Connect (OSTI)

    Elkin, F. S. [Institute for High Pressure Physics of Russian Academy of Sciences; Zibrov, I. P. [Institute for High Pressure Physics of Russian Academy of Sciences; Novikov, A. P. [Institute for High Pressure Physics of Russian Academy of Sciences; Khasanov, S. S. [Institute for Solid State Physics Russian Academy of Sciences; Sidorov, V. A. [Institute for High Pressure Physics of Russian Academy of Sciences; Petrova, A. E. [Institute for High Pressure Physics of Russian Academy of Sciences; Lograsso, Thomas A. [Ames Laboratory; Thompson, J. D. [Los Alamos National Laboratory; Stishov, S. M. [Institute for High Pressure Physics of Russian Academy of Sciences

    2013-12-06T23:59:59.000Z

    The volume change and heat capacity at the ferromagnetic phase transition in COS2 were measured at high pressures using X-rays generated by the Argonne synchrotron light source and by ac-calorimetry, respectively. The transition entropy, calculated on the basis of these experimental data, drops along the transition line due to quantum degradation, as required by Nernst's law. The volume change increases strongly along the transition line, which is explained by specifics of the compressibility difference of coexisting phases that results from nearly half metallic nature of the ferromagnetic phase of COS2. (C) 2013 Elsevier Ltd. All rights reserved.

  11. Hydrocarbon reaction with HF-cleaned Si(lOQ) and effects on metal-oxide-semiconductor device quality

    E-Print Network [OSTI]

    Rubloff, Gary W.

    Hydrocarbon reaction with HF-cleaned Si(lOQ) and effects on metal-oxide-semiconductor device-cleaned Si( 100) towards hydrocarbon adsorption is examined by surface analysis; most hydrocarbons adsorb oxidation after HF treatment.4'5 In this letter, passivation against hydrocarbon contamination is studied

  12. CO Oxidation on Pt-Group Metals from Ultrahigh Vacuum to Near Atmospheric Pressures. 2. Palladium and Platinum

    E-Print Network [OSTI]

    Goodman, Wayne

    CO Oxidation on Pt-Group Metals from Ultrahigh Vacuum to Near Atmospheric Pressures. 2. PalladiumVed: NoVember 3, 2008 CO oxidation on Pd(100), -(111), -(110), and Pt(110) single crystals was studied compositions. At low pressures the reaction fell into two regimes, one with a CO-dominant surface where the CO2

  13. Performance limits of tunnel transistors based on mono-layer transition-metal dichalcogenides

    SciTech Connect (OSTI)

    Jiang, Xiang-Wei, E-mail: xwjiang@semi.ac.cn; Li, Shu-Shen [State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2014-05-12T23:59:59.000Z

    Performance limits of tunnel field-effect transistors based on mono-layer transition metal dichalcogenides are investigated through numerical quantum mechanical simulations. The atomic mono-layer nature of the devices results in a much smaller natural length ?, leading to much larger electric field inside the tunneling diodes. As a result, the inter-band tunneling currents are found to be very high as long as ultra-thin high-k gate dielectric is possible. The highest on-state driving current is found to be close to 600??A/?m at V{sub g}?=?V{sub d}?=?0.5?V when 2?nm thin HfO{sub 2} layer is used for gate dielectric, outperforming most of the conventional semiconductor tunnel transistors. In the five simulated transition-metal dichalcogenides, mono-layer WSe{sub 2} based tunnel field-effect transistor shows the best potential. Deep analysis reveals that there is plenty room to further enhance the device performance by either geometry, alloy, or strain engineering on these mono-layer materials.

  14. Establishing Dual Electrogenerated Chemiluminescence and Multi-Color Electrochromism in Functional Ionic Transition Metal Complexes

    SciTech Connect (OSTI)

    Puodziukynaite, Egle; Oberst, Justin L.; Dyer, Aubrey L.; Reynolds, John R.

    2012-01-01T23:59:59.000Z

    A combination of electrochromism and electroluminescence in functional materials could lead to single-layer dual electrochromic/electroluminescent (EC/EL) display devices, capable of simultaneous operation in emissive and reflective modes. Whereas such next generation displays could provide optimal visibility in any ambient lighting situation, materials available that exhibit such characteristics in the active layer are limited due to the required intrinsic multifunctionality (i.e., redox activity, electroluminescence, electrochromism, and ion conductivity) and to date can only be achieved via the rational design of ionic transition-metal complexes. Reported herein is the synthesis and characterization of a new family of acrylate-containing ruthenium (tris)bipyridine-based coordination complexes with multifunctional characteristics. Potential use of the presented compounds in EC/EL devices is established, as they are applied as cross-linked electrochromic films and electrochemiluminescent layers in light-emitting electrochemical cell devices. Electrochromic switching of the polymeric networks between yellow, orange, green, brown and transmissive states is demonstrated, and electrochemiluminescent devices based on the complexes synthesized show red-orange to deep red emission with ?{sub max} ranging from 680 to 722 nm and luminance up to 135 cd/m{sup 2}. Additionally, a dual EC/EL device prototype is presented where light emission and multicolor electrochromism occur from the same pixel comprised of a single active layer, demonstrating a true combination of these properties in ionic transition-metal complexes.

  15. Beryllium Adsorption at Transition Aluminas: Implications for Environmental Science and Oxidation of Aluminum Alloys

    SciTech Connect (OSTI)

    Sergey N. Rashkeev; Michael V. Glazoff

    2010-08-01T23:59:59.000Z

    It is demonstrated that?gamma- and?eta- aluminas (transition Al2O3 polytypes with defect spinel structure) can effectively capture beryllium atoms. Although the bulk crystal structures of these two oxides are characterized only by slight differences in cation vacancy distributions, the interaction of Be with the two polytypes are different. For gamma- Al2O3, the Be adsorption energy is high (~ 5 eV per atom), and all Be atoms are captured and trapped at the surface - all attempts to move Be in the subsurface region result in its expulsion back to the surface. On the other hand, for ?eta- alumina Be atoms can be captured both at the surface and in octahedrally-coordinated subsurface cation vacancies. This result implies that both alumina oxides could be successfully used for Be capture out of wastewater streams related to industrial processes of aluminum and alumina production. Also, the surface adsorption mechanism of Be at?gamma- Al2O3 explains why very small additions of Be (of the order of several ppm) to Al-Mg and Al-Mg-Si casting and wrought alloys prevent run-away oxidation of these materials in molten state, as well as ingot cracking. We also discuss possibilities to use other additives (e.g., Ca and Sr) yielding the same protective effect for aluminum alloys but which are less toxic than beryllium.

  16. CO oxidation trends on Pt-group metals from ultrahigh vacuum to near atmospheric pressures: A combined in situ PM-IRAS and reaction kinetics study

    E-Print Network [OSTI]

    Goodman, Wayne

    CO oxidation trends on Pt-group metals from ultrahigh vacuum to near atmospheric pressures Accepted for publication 14 October 2008 Available online 5 November 2008 Keywords: Pt-group metals CO a c t The CO oxidation reaction on Pt-group metals (Pt, Rh, and Pd) has been investigated at low (610À

  17. Variation of the shape and morphological properties of silica and metal oxide powders by electro homogeneous precipitation

    DOE Patents [OSTI]

    Harris, Michael T. (Knoxville, TN); Basaran, Osman A. (Oak Ridge, TN); Sisson, Warren G. (Oak Ridge, TN); Brunson, Ronald R. (Lenoir City, TN)

    1997-01-01T23:59:59.000Z

    The present invention provides a method for preparing irreversible linear aggregates (fibrils) of metal oxide powders by utilizing static or pulsed DC electrical fields across a relatively non-conducting liquid solvent in which organometal compounds or silicon alkoxides have been dissolved. The electric field is applied to the relatively non-conducting solution throughout the particle formation and growth process promoting the formation of either linear aggregates (fibrils) or spherical shaped particles as desired. Thus the present invention provides a physical method for altering the size, shape and porosity of precursor hydrous metal oxide or hydrous silicon oxide powders for the development of advanced ceramics with improved strength and insulating capacity.

  18. ELM Control at the L-H Transition Achieved by Pellet Pacing in the All-metal Wall Tokamaks ASDEX Upgrade and JET

    E-Print Network [OSTI]

    ELM Control at the L-H Transition Achieved by Pellet Pacing in the All-metal Wall Tokamaks ASDEX Upgrade and JET

  19. Magnetic property of transition metal-Si atomic line on silicon ?3 grain boundary: A theoretical study

    SciTech Connect (OSTI)

    Li, Yong-Hua, E-mail: lyhua@shu.edu.cn; Guo, Shu-Kuan; Ma, Zhong-Quan; Qu, Guo-Hui; Shi, Ting-Ting; Xia, Qin [Department of Physics, SHU-Solar Energy R and D Laboratory, Shanghai University, Shanghai 200444 (China); Gong, Xin-Gao [Physics Department, Fudan University, Shanghai 200433 (China); Wei, Su-Huai [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)

    2014-06-14T23:59:59.000Z

    Using first-principles calculations within density functional theory, we investigate the electronic and magnetic properties of different 3d transition metal-Si atomic lines on silicon ?3 (112) grain boundary, which can be formed through grain boundary segregation. We find that (i) Fe atoms occupy the substitutional sites at the grain boundary and form an Fe-Si atomic line, but the interaction between the Fe atoms is antiferromagnetic. (ii) The ferromagnetic stability increases with the atomic number of the transition metals and Co-Si atomic line is more stable in the ferromagnetic phase and shows a semimetallic behavior. We suggest that this special TM-Si atomic line formed by thermodynamically favorable transition metal segregation on Si grain boundary could be used in design of spin-dependent quantum devices.

  20. Electronic Excitations and Metal-Insulator Transition inPoly(3-hexylthiophene) Organic Field-Effect Transistors

    SciTech Connect (OSTI)

    Sai, N.; Li, Z.Q.; Martin, M.C.; Basov, D.N.; Di Ventra, M.

    2006-11-07T23:59:59.000Z

    We carry out a comprehensive theoretical and experimentalstudy of charge injection in poly(3-hexylthiophene) (P3HT) to determinethe most likely scenario for metal-insulator transition in this system.Wecalculate the optical-absorption frequencies corresponding to a polaronand a bipolaron lattice in P3HT. We also analyze the electronicexcitations for three possible scenarios under which a first- or asecond-order metal-insulator transition can occur in doped P3HT. Thesetheoretical scenarios are compared with data from infrared absorptionspectroscopy on P3HT thin-film field-effect transistors (FETs). Ourmeasurements and theoretical predictions suggest that charge-inducedlocalized states in P3HT FETs are bipolarons and that the highest dopinglevel achieved in our experiments approaches that required for afirst-order metal-insulator transition.

  1. Solid oxide fuel cell with transitioned cross-section for improved anode gas management at the open end

    DOE Patents [OSTI]

    Zafred, Paolo R. (Murrysville, PA); Draper, Robert (Pittsburgh, PA)

    2012-01-17T23:59:59.000Z

    A solid oxide fuel cell (400) is made having a tubular, elongated, hollow, active section (445) which has a cross-section containing an air electrode (452) a fuel electrode (454) and solid oxide electrolyte (456) between them, where the fuel cell transitions into at least one inactive section (460) with a flattened parallel sided cross-section (462, 468) each cross-section having channels (472, 474, 476) in them which smoothly communicate with each other at an interface section (458).

  2. Effect of Temperature on GaGdO/GaN Metal Oxide Semiconductor Field Effect Transistors

    SciTech Connect (OSTI)

    Abernathy, C.R.; Baca, A.; Chu, S.N.G.; Hong, M.; Lothian, J.R.; Marcus, M.A.; Pearton, S.J.; Ren, F.; Schurman, M.J.

    1998-10-14T23:59:59.000Z

    GaGdO was deposited on GaN for use as a gate dielectric in order to fabricate a depletion metal oxide semiconductor field effect transistor (MOSFET). This is the fmt demonstration of such a device in the III-Nitride system. Analysis of the effect of temperature on the device shows that gate leakage is significantly reduced at elevated temperature relative to a conventional metal semiconductor field effeet transistor (MESFET) fabricated on the same GaN layer. MOSFET device operation in fact improved upon heating to 400 C. Modeling of the effeet of temperature on contact resistance suggests that the improvement is due to a reduction in the parasitic resistances present in the device.

  3. Rapid thermal cycling of metal-supported solid oxide fuel cellmembranes

    SciTech Connect (OSTI)

    Matus, Yuriy B.; De Jonghe, Lutgard C.; Jacobson, Craig P.; Visco, Steven J.

    2004-01-02T23:59:59.000Z

    Solid oxide fuel cell (SOFC) membranes were developed in which zirconia-based electrolyte thin films were supported by a composite metal/ceramic electrode, and were subjected to rapid thermal cycling between 200 and 800 C. The effects of this cycling on membrane performance were evaluated. The membranes, not yet optimized for performance, showed a peak power density of 350mW/cm2at 900 C in laboratory-sized SOFCs that was not affected by the thermal cycling. This resistance to cycling degradation is attributed to the close matching of thermal expansion coefficient of the cermet support electrode with that of the zirconia electrolyte.

  4. Characterization of a Fe/Y[subscript 2]O[subscript 3] metal/oxide interface using neutron and x-ray scattering

    E-Print Network [OSTI]

    Watkins, E. B.

    The structure of metal/oxide interfaces is important to the radiation resistance of oxide dispersion-strengthened steels. We find evidence of gradual variations in stoichiometry and magnetization across a Fe/Y[subscript ...

  5. Magnetically Driven Metal-Insulator Transition in NaOsO3

    SciTech Connect (OSTI)

    Calder, Stuart A [ORNL; Christianson, Andrew D [ORNL; Lumsden, Mark D [ORNL; Lang, Jonathan [Argonne National Laboratory (ANL); Stone, Matthew B [ORNL; McMorrow, D. F. [University College, London; Garlea, Vasile O [ORNL; Kim, Jong-Woo [Argonne National Laboratory (ANL); Schlueter, J. A. [Argonne National Laboratory (ANL); Shi, Y. G. [Chinese Academy of Sciences; Yamaura, K. [National Institute for Materials Science, Tsukuba, Japan; Sun, Y. S. [MANA; Tsujimoto, Y. [Kyoto University, Japan

    2012-01-01T23:59:59.000Z

    The metal-insulator transition (MIT) is one of the most dramatic manifestations of electron correlations in materials. Various mechanisms producing MITs have been extensively considered, including the Mott (electron localization via Coulomb repulsion), Anderson (localization via disorder), and Peierls (local- ization via distortion of a periodic one-dimensional lattice) mechanisms. One additional route to a MIT proposed by Slater, in which long-range magnetic order in a three dimensional system drives the MIT, has received relatively little attention. Using neutron and x-ray scattering we show that the MIT in NaOsO3 is coincident with the onset of long-range commensurate three dimensional magnetic order. While candidate materials have been suggested, our experimental methodology allows the first definitive demonstration of the long predicted Slater MIT.

  6. Transition Metal Catalyzed Reactions of Carbohydrates: a Nonoxidative Approach to Oxygenated Organics

    SciTech Connect (OSTI)

    Andrews, Mark

    1997-01-08T23:59:59.000Z

    There is a critical need for new environmentally friendly processes in the United States chemical industry as legislative and economic pressures push the industry to zero-waste and cradle-to-grave responsibility for the products they produce. Carbohydrates represent a plentiful, renewable resource, which for some processes might economically replace fossil feedstocks. While the conversion of biomass to fuels, is still not generally economical, the selective synthesis of a commodity or fine chemical, however, could compete effectively if appropriate catalytic conversion systems can be found. Oxygenated organics, found in a variety of products such as nylon and polyester, are particularly attractive targets. We believe that with concerted research efforts, homogeneous transition metal catalyzed reactions could play a significant role in bringing about this future green chemistry technology.

  7. Study of intermediates from transition metal excited-state electron-transfer reactions

    SciTech Connect (OSTI)

    Hoffman, M.Z.

    1991-12-31T23:59:59.000Z

    During this period, conventional and fast-kinetics techniques of photochemistry, photophysics, radiation chemistry, and electrochemistry were used for the characterization of the intermediates that are involved in transition metal excited-state electron-transfer reactions. The intermediates of interest were the excited states of Ru(II) and Cr(III) photosensitizers, their reduced forms, and the species formed in the reactions of redox quenchers and electron-transfer agents. Of particular concern has been the back electron-transfer reaction between the geminate pair formed in the redox quenching of the photosensitizers, and the dependence of its rate on solution medium and temperature in competition with transformation and cage escape processes.

  8. Thermoelectric material including a multiple transition metal-doped type I clathrate crystal structure

    DOE Patents [OSTI]

    Yang, Jihui (Lakeshore, CA); Shi, Xun (Troy, MI); Bai, Shengqiang (Shanghai, CN); Zhang, Wenqing (Shanghai, CN); Chen, Lidong (Shanghai, CN); Yang, Jiong (Shanghai, CN)

    2012-01-17T23:59:59.000Z

    A thermoelectric material includes a multiple transition metal-doped type I clathrate crystal structure having the formula A.sub.8TM.sub.y.sub.1.sup.1TM.sub.y.sub.2.sup.2 . . . TM.sub.y.sub.n.sup.nM.sub.zX.sub.46-y.sub.1.sub.-y.sub.2.sub.- . . . -y.sub.n.sub.-z. In the formula, A is selected from the group consisting of barium, strontium, and europium; X is selected from the group consisting of silicon, germanium, and tin; M is selected from the group consisting of aluminum, gallium, and indium; TM.sup.1, TM.sup.2, and TM.sup.n are independently selected from the group consisting of 3d, 4d, and 5d transition metals; and y.sub.1, y.sub.2, y.sub.n and Z are actual compositions of TM.sup.1, TM.sup.2, TM.sup.n, and M, respectively. The actual compositions are based upon nominal compositions derived from the following equation: z=8q.sub.A-|.DELTA.q.sub.1|y.sub.1-|.DELTA.q.sub.2|y.sub.2- . . . -|.DELTA.q.sub.n|y.sub.n, wherein q.sub.A is a charge state of A, and wherein .DELTA.q.sub.1, .DELTA.q.sub.2, .DELTA.q.sub.n are, respectively, the nominal charge state of the first, second, and n-th TM.

  9. Speciation and Fate of Trace Metals in Estuarine Sediments Under Reduced and Oxidized Conditions, Seaplane Lagoon, Alameda Naval Air Station

    SciTech Connect (OSTI)

    Carroll, S A; Day, P A; Esser, B; Randall, S

    2002-10-18T23:59:59.000Z

    We have identified important chemical reactions that control the fate of metal-contaminated estuarine sediments if they are left undisturbed (in situ) or if they are dredged. We combined information on the molecular bonding of metals in solids from X-ray absorption spectroscopy (XAS) with thermodynamic and kinetic driving forces obtained from dissolved metal concentrations to deduce the dominant reactions under reduced and oxidized conditions. We evaluated the in situ geochemistry of metals (cadmium, chromium, iron, lead, manganese and zinc) as a function of sediment depth (to 100 cm) from a 60-year record of contamination at the Alameda Naval Air Station, California. Results from XAS and thermodynamic modeling of porewaters show that cadmium and most of the zinc form stable sulfide phases, and that lead and chromium are associated with stable carbonate, phosphate, phyllosilicate, or oxide minerals. Therefore, there is minimal risk associated with the release of these trace metals from the deeper sediments contaminated prior to the Clean Water Act (1975) as long as reducing conditions are maintained. Increased concentrations of dissolved metals with depth were indicative of the formation of metal HS- complexes. The sediments also contain zinc, chromium, and manganese associated with detrital iron-rich phyllosilicates and/or oxides. These phases are recalcitrant at near-neutral pH and do not undergo reductive dissolution within the 60-year depositional history of sediments at this site. The fate of these metals during dredging was evaluated by comparing in situ geochemistry with that of sediments oxidized by seawater in laboratory experiments. Cadmium and zinc pose the greatest hazard from dredging because their sulfides were highly reactive in seawater. However, their dissolved concentrations under oxic conditions were limited eventually by sorption to or co-precipitation with an iron (oxy)hydroxide. About 50% of the reacted CdS and 80% of the reacted ZnS were bonded to an oxide-substrate at the end of the 90-day oxidation experiment. Lead and chromium pose a minimal hazard from dredging because they are bonded to relatively insoluble carbonate, phosphate, phyllosilicate, or oxide minerals that are stable in seawater. These results point out the specific chemical behavior of individual metals in estuarine sediments, and the need for direct confirmation of metal speciation in order to constrain predictive models that realistically assess the fate of metals in urban harbors and coastal sediments.

  10. Effect of pre-oxidation and environmental aging on the seal strength of a novel high-temperature solid oxide fuel cell (SOFC) sealing glass with metallic interconnect

    SciTech Connect (OSTI)

    Chou, Y. S.; Stevenson, Jeffry W.; Singh, Prabhakar

    2008-09-15T23:59:59.000Z

    A novel high-temperature alkaline-earth silicate sealing glass was developed for solid oxide fuel cell (SOFC) applications. The glass was used to join two ferritic stainless steel coupons for strength evaluation. The steel coupons were pre-oxidized at elevated temperatures to promote thick oxide layers to simulate long-term exposure conditions. In addition, seals to as-received metal coupons were also tested after aging in oxidizing or reducing environments to simulate the actual SOFC environment. Room temperature tensile testing showed strength degradation when using pre-oxidized coupons, and more extensive degradation after aging in air. Fracture surface and microstructural analysis confirmed that the cause of degradation was formation of SrCrO4 at the outer sealing edges exposed to air.

  11. Electropholic Transition Metal Complexes: Catalysis of Isotope Exchange. April 1, 1992 - December 3, 1996. Final Report.

    SciTech Connect (OSTI)

    Heinekey, D. Michael

    1997-04-06T23:59:59.000Z

    The central aim of this project is to exploit transition metal dihydrogen complexes to develop catalysts for isotope exchange reactions between hydrogen and substrates such as water. The authors have partially met this goal by the synthesis of novel cationic rhenium complexes of the form [Re(CO){sub 3}(PR{sub 3}){sub 2}(H{sub 2})]{sup +}. These complexes bind hydrogen somehwat more strongly than the neutral tungsten analogs but also activate the bound H{sub 2} to heterolytic cleavage. Thus rapid proton (deuteron) exchange between hydrogen and water can be achieved. An example of this reaction is the rapid formation of bound HD from the complex [Re(CO){sub 3}(PR{sub 3}){sub 2}(H{sub 2})]{sup +} and deuterium gas. Rapid incorporation of deuterium from D{sub 2}O has also been observed. In these systems, the competitive binding of water to the metal center is a drawback. The affinity of the Re center for water depends upon the nature of the phosphine ligands, with the presumably more electrophilic PPh{sub 3} complex binding water strongly and irreversibly, while the PCy{sub 3} complex binds water reversibly. These results have been published in J.Am.Chem.Soc 1994, 116, 4515 and J.Am.Chem.Soc 1997, 119, 4172.

  12. Ab initio study of lithium intercalation in metal oxides and metal dichalcogenides M. K. Aydinol, A. F. Kohan, and G. Ceder

    E-Print Network [OSTI]

    Ceder, Gerbrand

    -metal-oxides due to their application potential as rechargeable battery electrodes1 and electrochromic displays.2. In electrochromic applications, band filling is used to adjust the electronic and optical properties.3 Figure 1-potential difference between cathode and anode is desirable as this leads to a high OCV. For electrochromic

  13. Bonding in transition-metal cluster compounds. 1. The M/sub 6/(. mu. /sub 3/-X)/sub 8/ cluster

    SciTech Connect (OSTI)

    Woolley, R.G.

    1985-10-23T23:59:59.000Z

    The electronic structure of the transition-metal cluster moiety M/sub 6/(..mu../sub 3/-X)/sub 8/, with idealized O/sub h/ symmetry, is examined for X = chalcogen, halogen, and carbonyl ligands. The role of the metal d electrons in metal-metal bonding is emphasized, and the structure of the metal cluster d-band is described in detail. 54 references, 4 figures.

  14. First-principles prediction of redox potentials in transition-metal compounds with LDA+U Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA

    E-Print Network [OSTI]

    Ceder, Gerbrand

    , such as those at which lithium intercalates in transition metal compounds. We argue that this inaccuracy this approach, the experimental lithium intercalation voltages of a number of transition metal compounds corrosion, fuel cells and rechargeable Li batteries, and the ability to study these processes from first

  15. Time-resolved x-ray absorption spectroscopy of photoinduced insulator-metal transition in a colossal magnetoresistive manganite

    SciTech Connect (OSTI)

    Rini, M.; Tobey, R.; Wall, S.; Zhu, Y.; Tomioka, Y.; Tokura, Y.; Cavalleri, A.; Schoenlein, R.W.

    2008-08-01T23:59:59.000Z

    We studied the ultrafast insulator-metal transition in a manganite by means of picosecond X-ray absorption at the O K- and Mn L-edges, probing photoinduced changes in O-2p and Mn-3d electronic states near the Fermi level.

  16. MetalBosonic InsulatorSuperconductor Transition in Boron-Doped Granular Diamond Gufei Zhang,1,* Monika Zeleznik,2

    E-Print Network [OSTI]

    Bristol, University of

    . Second, the giant RðTÞ peak is observed in heavily boron-doped polycrystalline diamond thick filmsMetal­Bosonic Insulator­Superconductor Transition in Boron-Doped Granular Diamond Gufei Zhang,1 the onset of superconductivity in heavily boron-doped diamond. This anomalous RðTÞ peak in a 3D system

  17. Functional Materials Letters (FML) Metal-to-dielectric transition induced by annealing of oriented titanium thin films

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    titanium thin films --Manuscript Draft-- Manuscript Number: Full Title: Metal-to-dielectric transition induced by annealing of oriented titanium thin films Article Type: Research Paper Section/Category: Prof. Order of Authors Secondary Information: Abstract: Titanium thin films were deposited by dc magnetron

  18. Synchronization of pairwise-coupled, identical, relaxation oscillators based on metal-insulator phase transition devices: A Model Study

    E-Print Network [OSTI]

    Abhinav Parihar; Nikhil Shukla; Suman Datta; Arijit Raychowdhury

    2014-08-11T23:59:59.000Z

    Computing with networks of synchronous oscillators has attracted wide-spread attention as novel materials and device topologies have enabled realization of compact, scalable and low-power coupled oscillatory systems. Of particular interest are compact and low-power relaxation oscillators that have been recently demonstrated using MIT (metal- insulator-transition) devices using properties of correlated oxides. This paper presents an analysis of the dynamics and synchronization of a system of two such identical coupled relaxation oscillators implemented with MIT devices. We focus on two implementations of the oscillator: (a) a D-D configuration where complementary MIT devices (D) are connected in series to provide oscillations and (b) a D-R configuration where it is composed of a resistor (R) in series with a voltage-triggered state changing MIT device (D). The MIT device acts like a hysteresis resistor with different resistances in the two different states. The synchronization dynamics of such a system has been analyzed with purely charge based coupling using a resistive (Rc) and a capacitive (Cc) element in parallel. It is shown that in a D-D configuration symmetric, identical and capacitively coupled relaxation oscillator system synchronizes to an anti-phase locking state, whereas when coupled resistively the system locks in phase. Further, we demonstrate that for certain range of values of Rc and Cc, a bistable system is possible which can have potential applications in associative computing. In D-R configuration, we demonstrate the existence of rich dynamics including non-monotonic flows and complex phase relationship governed by the ratios of the coupling impedance. Finally, the developed theoretical formulations have been shown to explain experimentally measured waveforms of such pairwise coupled relaxation oscillators.

  19. Catalytic hydrogenation and gas permeation properties of metal-containing poly(phenylene oxide) and polysulfone

    SciTech Connect (OSTI)

    Hanrong Gao; Yun Xu; Shijian Liao; Ren Liu; Daorong Yu (Chinese Academy of Sciences, Dalian (China). Dalian Inst. of Chemical Physics)

    1993-11-10T23:59:59.000Z

    Metal-containing polymers, PPL-DPP-Pd, PPO-CPA-Pd, PSF-DPP-Pd, PSF-CPA-Pd (PDD = diphenylphosphinyl, CPA = o-carboxy phenyl amino), PPO-M (M = Pd,Cu,Co,Ni), and PSF-Pd, were prepared by incorporating metal chloride with either modified or unmodified poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) and polysulfone (PSF). The Pd-containing polymers exhibit catalytic activity in the hydrogenation of cyclopentadiene under mild conditions both in alcohol solution and in the gas phase. The selectivity in the hydrogenation of diene to monoene in the gas phase can be controlled by adjusting the hydrogen partial pressure. The metal-containing polymers, PPL-M and PSF-Pd, can be cast easily into the membranes. The H[sub 2]/N[sub 2] permselectivity for PPO-M is higher than that for unmodified PPO, whereas the permeability of H[sub 2] changes slightly. The H[sub 2] permeability and H[sub 2]/N[sub 2] permselectivity for the PPO-Pd membrane are up to 67.5 barrers and 135, respectively.

  20. Method and apparatus for preparation of spherical metal carbonates and lithium metal oxides for lithium rechargeable batteries

    DOE Patents [OSTI]

    Kang, Sun-Ho (Naperville, IL); Amine, Khalil (Downers Grove, IL)

    2008-10-14T23:59:59.000Z

    A number of materials with the composition Li.sub.1+xNi.sub..alpha.Mn.sub..beta.Co.sub..gamma.M'.sub..delta.O.sub.2-- zF.sub.z (M'=Mg,Zn,Al,Ga,B,Zr,Ti) for use with rechargeable batteries, wherein x is between about 0 and 0.3, .alpha. is between about 0.2 and 0.6, .beta. is between about 0.2 and 0.6, .gamma. is between about 0 and 0.3, .delta. is between about 0 and 0.15, and z is between about 0 and 0.2. Adding the above metal and fluorine dopants affects capacity, impedance, and stability of the layered oxide structure during electrochemical cycling. Another aspect of the invention includes materials with the composition Li.sub.1+xNi.sub..alpha.Co.sub..beta.Mn.sub..gamma.M'.sub..delta.O.sub.yF- .sub.z (M'=Mg,Zn,Al,Ga,B,Zr,Ti), where the x is between 0 and 0.2, the .alpha. between 0 and 1, the .beta. between 0 and 1, the .gamma. between 0 and 2, the .delta. between about 0 and about 0.2, the y is between 2 and 4, and the z is between 0 and 0.5.

  1. Group 4 Metalloporphyrin diolato Complexes and Catalytic Application of Metalloporphyrins and Related Transition Metal Complexes

    SciTech Connect (OSTI)

    Guodong Du

    2004-12-19T23:59:59.000Z

    In this work, the first examples of group 4 metalloporphyrin 1,2-diolato complexes were synthesized through a number of strategies. In general, treatment of imido metalloporphyrin complexes, (TTP)M=NR, (M = Ti, Zr, Hf), with vicinal diols led to the formation of a series of diolato complexes. Alternatively, the chelating pinacolate complexes could be prepared by metathesis of (TTP)MCl{sub 2} (M = Ti, Hf) with disodium pinacolate. These complexes were found to undergo C-C cleavage reactions to produce organic carbonyl compounds. For titanium porphyrins, treatment of a titanium(II) alkyne adduct, (TTP)Ti({eta}{sup 2}-PhC{triple_bond}CPh), with aromatic aldehydes or aryl ketones resulted in reductive coupling of the carbonyl groups to produce the corresponding diolato complexes. Aliphatic aldehydes or ketones were not reactive towards (TTP)Ti({eta}{sup 2}-PhC{triple_bond}CPh). However, these carbonyl compounds could be incorporated into a diolato complex on reaction with a reactive precursor, (TTP)Ti[O(Ph){sub 2}C(Ph){sub 2}O] to provide unsymmetrical diolato complexes via cross coupling reactions. In addition, an enediolato complex (TTP)Ti(OCPhCPhO) was obtained from the reaction of (TTP)Ti({eta}{sup 2}-PhC{triple_bond}CPh) with benzoin. Titanium porphyrin diolato complexes were found to be intermediates in the (TTP)Ti=O-catalyzed cleavage reactions of vicinal diols, in which atmospheric oxygen was the oxidant. Furthermore, (TTP)Ti=O was capable of catalyzing the oxidation of benzyl alcohol and {alpha}-hydroxy ketones to benzaldehyde and {alpha}-diketones, respectively. Other high valent metalloporphyrin complexes also can catalyze the oxidative diol cleavage and the benzyl alcohol oxidation reactions with dioxygen. A comparison of Ti(IV) and Sn(IV) porphyrin chemistry was undertaken. While chelated diolato complexes were invariably obtained for titanium porphyrins on treatment with 1,2-diols, the reaction of vicinal diols with tin porphyrins gave a number of products, including mono-, bis-alkoxo, and chelating diolato complexes, depending on the identity of diols and the stoichiometry employed. It was also found that tin porphyrin complexes promoted the oxidative cleavage of vicinal diols and the oxidation of {alpha}-ketols to {alpha}-diketones with dioxygen. In extending the chemistry of metalloporphyrins and analogous complexes, a series of chiral tetraaza macrocyclic ligands and metal complexes were designed and synthesized. Examination of iron(II) complexes showed that they were efficient catalysts for the cyclopropanation of styrene by diazo reagents. Good yields and high diastereoselectivity were obtained with modest enantioselectivity. A rationalization of the stereoselectivity was presented on the basis of structural factors in a carbene intermediate.

  2. Specific-Heat of the Organic Metal Bis(tetrathiotetracene) Tri-Iodide from 20-K to 100-K, the Vicinity of the Metal-Nonmetal Phase-Transition

    E-Print Network [OSTI]

    CORT, B.; Naugle, Donald G.

    1981-01-01T23:59:59.000Z

    selenium ana- log, the transition-metal complex KCP, ' and tetrathiofulvalenium-thiocyanate [TTF(SCN) 0588] and its selenium analog' which are similar to the organic metal studied in this work. That the metallic state is stabilized by impurities...PHYSICAL REVIEW B VOLUME 24, NUMBER 7 1 OCTOBER 1981 Specific heat of the organic metal bis(tetrathiotetracene) tri-iodide from 20 to 100 K, the vicinity of the metal-nonmetal phase transition B. Cort' and D. G. Naugle Department of Physics...

  3. Porphyrins and metal complexes thereof having haloalkyl side chains

    DOE Patents [OSTI]

    Wijesekera, Tilak (Glen Mills, PA); Lyons, James E. (Wallingford, PA); Ellis, Jr., Paul E. (Downingtown, PA); Bhinde, Manoj V. (Boothwyn, PA)

    1997-01-01T23:59:59.000Z

    Transition metal complexes of meso-haloalkylporphyrins, wherein the haloalkyl groups contain 2 to 8 carbon atoms have been found to be highly effective catalysts for oxidation of alkanes and for the decomposition of hydroperoxides.

  4. Porphyrins and metal complexes thereof having haloalkyl side chains

    DOE Patents [OSTI]

    Wijesekera, T.; Lyons, J.E.; Ellis, P.E. Jr.; Bhinde, M.V.

    1997-03-04T23:59:59.000Z

    Transition metal complexes of meso-haloalkylporphyrins, wherein the haloalkyl groups contain 2 to 8 carbon atoms have been found to be highly effective catalysts for oxidation of alkanes and for the decomposition of hydroperoxides. 7 figs.

  5. Study of gate oxide traps in HfO[subscript 2]/AlGaN/GaN metal-oxide-semiconductor high-electron-mobility transistors by use of ac transconductance method

    E-Print Network [OSTI]

    Sun, X.

    We introduce an ac-transconductance method to profile the gate oxide traps in a HfO[subscript 2] gated AlGaN/GaN Metal-Oxide-Semiconductor High-Electron-Mobility Transistors (MOS-HEMTs) that can exchange carriers with metal ...

  6. alkali-transition metal borohydrides: Topics by E-print Network

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

    size, voltage, orientation and geometries of the electrodes to control the liquid metal transformers were clarified. Such events are hard to achieve otherwise on rigid metal or...

  7. Process for improving metal production in steelmaking processes

    DOE Patents [OSTI]

    Pal, U.B.; Gazula, G.K.M.; Hasham, A.

    1996-06-18T23:59:59.000Z

    A process and apparatus for improving metal production in ironmaking and steelmaking processes is disclosed. The use of an inert metallic conductor in the slag containing crucible and the addition of a transition metal oxide to the slag are the disclosed process improvements. 6 figs.

  8. Process for improving metal production in steelmaking processes

    DOE Patents [OSTI]

    Pal, Uday B. (Malden, MA); Gazula, Gopala K. M. (Somerville, MA); Hasham, Ali (Karachi, PK)

    1996-01-01T23:59:59.000Z

    A process and apparatus for improving metal production in ironmaking and steelmaking processes is disclosed. The use of an inert metallic conductor in the slag containing crucible and the addition of a transition metal oxide to the slag are the disclosed process improvements.

  9. Oxidation/corrosion of metallic and ceramic materials in an aluminum remelt furnace. [For fluidized bed waste heat recovery systems

    SciTech Connect (OSTI)

    Federer, J.I.; Jones, P.J.

    1985-12-01T23:59:59.000Z

    Both metallic alloys and ceramic materials are candidates for the distributor plate and other components of fluidized bed waste heat recovery (FBWHR) systems. Eleven Fe-, Ni-, and Co-base alloys were exposed to air at elevated temperatures in laboratory furnaces and to flue gases in an aluminum remelt furnace to assess their resistance to oxidation and corrosion. Four SiC ceramics and two oxide ceramics were also tested in the aluminum remelt furnace. Some alloys were coated with aluminum or SiO2 by commercial processes in an effort to enhance their oxidation and corrosion resistance.

  10. Dilute magnetic semiconductor and half-metal behaviour mediated by 3d transition-metal doped in black/blue phosphorene

    E-Print Network [OSTI]

    Yu, Weiyang; Niu, Chun-Yao; Li, Chong; Cho, Jun-Hyung; Jia, Yu

    2015-01-01T23:59:59.000Z

    Using first-principles calculations, we present a theoretical study of the structural, electronic and magnetic properties of 3d transition metal (TM) atoms interacting with phosphorus monovacancies in two-dimensional black/blue phosphorene. We pay special attention to the magnetic properties of these substitutional impurities and find that they can be fully understood by a simple model based on the Hund's rule. For TM-doped black phosphorene, the calculated band structures of substitutional Ti, Cr, Mn, Fe and Ni impurities show dilute magnetic semiconductor (DMS) properties while those of substitutional Sc, V and Co impurities show nonmagnetic property. For TM-doped blue phosphorene, the calculated band structures of substitutional V, Cr, Mn and Fe impurities show DMS properties, and those of substitutional Ti and Ni impurities show half-metal properties, while Sc and V impurities show nonmagnetic property. We identify three different regimes associated with the occupation of different phosphorus-metal hybrid...

  11. Heterojunction thin films based on multifunctional metal oxides for photovoltaic application

    SciTech Connect (OSTI)

    Prabhu, M.; Soundararajan, N.; Ramachandran, K. [School of Physics, Madurai Kamaraj University, Madurai - 625021 (India); Marikkannan, M.; Mayandi, J. [School of Chemistry, Madurai Kamaraj University, Madurai - 625021 (India)

    2014-04-24T23:59:59.000Z

    Metal oxides based multifunctional heterojunction thin films of ZnO/SnO{sub 2} and ZnO/SnO{sub 2}/CuO QDs were prepared by spin-coating technique. The crystallographic properties and the surface morphologies of the films were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The optical absorption studies revealed that the film thickness has considerable effect on the band gap values and is found to be in the range of 3.73–3.48 eV. The photoluminescence spectra showed several weak visible emission peaks related to the deep level defects (450-575 nm). Finally, the current density-voltage (J-V) characteristic of ZnO/SnO{sub 2}/CuO QDs (ZSCI) based heterojunction thin film coated on ITO is also reported.

  12. HEU to LEU conversion and blending facility: Metal blending alternative to produce LEU oxide for disposal

    SciTech Connect (OSTI)

    NONE

    1995-09-01T23:59:59.000Z

    US DOE is examining options for disposing of surplus weapons-usable fissile materials and storage of all weapons-usable fissile materials. The nuclear material is converted to a form more proliferation- resistant than the original form. Blending HEU (highly enriched uranium) with less-enriched uranium to form LEU has been proposed as a disposition option. Five technologies are being assessed for blending HEU. This document provides data to be used in environmental impact analysis for the HEU-LEU disposition option that uses metal blending with an oxide waste product. It is divided into: mission and assumptions, conversion and blending facility descriptions, process descriptions and requirements, resource needs, employment needs, waste and emissions from plant, hazards discussion, and intersite transportation.

  13. Method for producing metal oxide aerogels having densities less than 0. 02 g/cc

    DOE Patents [OSTI]

    Tillotson, T.M.; Poco, J.F.; Hrubesh, L.W.; Thomas, I.M.

    1994-01-04T23:59:59.000Z

    A two-step method is described for making transparent aerogels which have a density of less than 0.003 g/cm[sup 3] to those with a density of more than 0.8 g/cm[sup 3], by a sol/gel process and supercritical extraction. Condensed metal oxide intermediate made with purified reagents can be diluted to produce stable aerogels with a density of less than 0.02 g/cm[sup 3]. High temperature, direct supercritical extraction of the liquid phase of the gel produces hydrophobic aerogels which are stable at atmospheric moisture conditions. Monolithic, homogeneous silica aerogels with a density of less than 0.02 to higher than 0.8 g/cm[sup 3], with high thermal insulation capacity, improved mechanical strength and good optical transparency, are described. 7 figures.

  14. Method for producing metal oxide aerogels having densities less than 0.02 g/cc

    DOE Patents [OSTI]

    Tillotson, Thomas M. (Tracy, CA); Poco, John F. (Livermore, CA); Hrubesh, Lawrence W. (Pleasanton, CA); Thomas, Ian M. (Livermore, CA)

    1994-01-01T23:59:59.000Z

    A two-step method is described for making transparent aerogels which have a density of less than 0.003 g/cm.sup.3 to those with a density of more than 0.8 g/cm.sup.3, by a sol/gel process and supercritical extraction. Condensed metal oxide intermediate made with purified reagents can be diluted to produce stable aerogels with a density of less than 0.02 g/cm.sup.3. High temperature, direct supercritical extraction of the liquid phase of the gel produces hydrophobic aerogels which are stable at atmospheric moisture conditions. Monolithic, homogeneous silica aerogels with a density of less than 0.02 to higher than 0.8 g/cm.sup.3, with high thermal insulation capacity, improved mechanical strength and good optical transparency, are described.

  15. Lattice location of transition metals in silicon by means of emission channeling

    E-Print Network [OSTI]

    da Silva, Daniel José; Wahl, Ulrich; Correia, João Guilherme

    The behavior of transition metals (TMs) in silicon is a subject that has been studied extensively during the last six decades. Their unintentional introduction during the Si production, crystal growth and device manufacturing have made them difficult contaminants to avoid. Once in silicon they easily form deep levels, either when in the isolated form or when forming precipitates. One important effect is the reduction of efficiency of silicon-based devices, being dramatic, in particular, in photovoltaic applications. One way to avoid such effects is by engineering the location of the TM: some TM complexes or lattice sites of the isolated form do not introduce any level in the silicon bandgap. Which point defects lead to such passivation is still under debate. Another way is to mitigate the reduction of efficiency by reducing the dangling bonds of TMs with hydrogen. The most important and commonly used procedures to diminish the unwanted effects of the introduced deep levels are, nevertheless, based on the so-c...

  16. Most spin-1/2 transition-metal ions do have single ion anisotropy

    SciTech Connect (OSTI)

    Liu, Jia; Whangbo, Myung-Hwan, E-mail: hxiang@fudan.edu.cn, E-mail: mike-whangbo@ncsu.edu [Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695 (United States); Koo, Hyun-Joo [Department of Chemistry and Research Institute for Basic Sciences, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Xiang, Hongjun, E-mail: hxiang@fudan.edu.cn, E-mail: mike-whangbo@ncsu.edu [Key Laboratory of Computational Physical Sciences (Ministry of Education), State Key Laboratory of Surface Physics, and Department of Physics, Fudan University, Shanghai 200433 (China); Kremer, Reinhard K. [Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart (Germany)

    2014-09-28T23:59:59.000Z

    The cause for the preferred spin orientation in magnetic systems containing spin-1/2 transition-metal ions was explored by studying the origin of the easy-plane anisotropy of the spin-1/2 Cu{sup 2+} ions in CuCl{sub 2}·2H{sub 2}O, LiCuVO{sub 4}, CuCl{sub 2}, and CuBr{sub 2} on the basis of density functional theory and magnetic dipole-dipole energy calculations as well as a perturbation theory treatment of the spin-orbit coupling. We find that the spin orientation observed for these spin-1/2 ions is not caused by their anisotropic spin exchange interactions, nor by their magnetic dipole-dipole interactions, but by the spin-orbit coupling associated with their crystal-field split d-states. Our study also predicts in-plane anisotropy for the Cu{sup 2+} ions of Bi{sub 2}CuO{sub 4} and Li{sub 2}CuO{sub 2}. The results of our investigations dispel the mistaken belief that magnetic systems with spin-1/2 ions have no magnetic anisotropy induced by spin-orbit coupling.

  17. TECHNOLOGICAL IMPROVEMENTS OF A METAL OXIDE GAS MULTI-SENSOR BASED ON A MICRO-HOTPLATE STRUCTURE AND INKJET DEPOSI-

    E-Print Network [OSTI]

    (CO-100ppm, NO2-0.2ppm, NH3- 5ppm and C2H4O-2ppm). Keywords: Gas Sensors, Metal Oxides (MOX), Micro on the fact that the current/voltage characteristic of MOX films exhibits a non-linear behavior [7]. More presented here aims at presenting and characterizing an optimized MOX multi-sensor struc- ture developed

  18. Pressure-Volume-Temperature Studies of Metal-Oxide Pairs [1] Cottrell E. et al. (2007) This meeting.

    E-Print Network [OSTI]

    Campbell, Andrew

    2007-01-01T23:59:59.000Z

    for the two phases. fO2 Buffers at High Pressure For the general metal-oxide reaction M + x/2 O2 = MOx, the fO2 is related to the Gibbs energies (G) by x/2 RT ln fO2 = G(MOx) ­ G(M). The pressure effect

  19. AlGaN/GaN Metal Oxide Semiconductor Field Effect Transistors using Titanium Dioxide P. J. HANSEN

    E-Print Network [OSTI]

    York, Robert A.

    AlGaN/GaN Metal Oxide Semiconductor Field Effect Transistors using Titanium Dioxide P. J. HANSEN 1 epitaxially on AlGaN/GaN HFET structures by molecular beam epitaxy (MBE). Growth was first performed on GaN templates to establish epitaxial growth conditions. X-ray diffraction showed [001] TiO2 || [1010]GaN

  20. Picosecond soft X-ray absorption measurement of the photo-inducedinsulator-to-metal transition in VO2.

    SciTech Connect (OSTI)

    Cavalleri, Andrea; Chong, Henry H.W.; Fourmaux, Sylvain; Glover,Thornton E.; Heimann, Phil A.; Kieffer, Jean Claude; Mun, B. Simon; Padmore, Howard A.; Schoenlein, Robert W.

    2004-02-01T23:59:59.000Z

    We directly measure the photoinduced insulator-to-metal transition in VO2 using time-resolved near-edge x-ray absorption. Picosecond pulses of synchrotron radiation are used to detect the redshift in the vanadium L3edge at 516 eV, which is associated with the transient collapse of the low-temperature band gap. We identify a two-component temporal response, corresponding to an ultrafast transformation over a 50 nm surface layer, followed by 40 m/s thermal growth of the metallic phase into the bulk.

  1. Fast photoreactions of ethanol and MTBE on tropospheric metal oxide particles

    SciTech Connect (OSTI)

    Idriss, H.; Seebauer, E.G. [Univ. of Illinois, Urbana, IL (United States)

    1995-12-31T23:59:59.000Z

    Ethanol (EtOH) and tert-Butyl methyl ether (MTBE) are both finding increased use as oxygenated additives to fuels. However, the environmental fate in the troposphere of these species is unclear when they escape as fugitive emissions. In several locations there are reports of human illness in response to MTBE in particular. Volatile organic compounds (VOC`s) such as these are generally thought to react by a variety of homogeneous free-radical mechanisms, usually beginning with attack by OH radical. However, we show by laboratory kinetic studies that the heterogeneous photoreaction on solid suspended metal-oxide particulates such as fly ash proceeds with a comparable rate, especially in urban environments. EtOH reacts to form acetaldehyde, and EtOH forms isobutene, methanol, and formaldehyde. Our work appears to be the first-ever demonstration that VOC`s can react as fast by a heterogeneous mechanism as by a homogeneous one in the atmosphere. Experiments by various optical and kinetic techniques show that the active phases in fly ash are Fe oxides, which are fairly abundant in other atmospheric particulates as well.

  2. Variation of the shape and morphological properties of silica and metal oxide powders by electro homogeneous precipitation

    DOE Patents [OSTI]

    Harris, M.T.; Basaran, O.A.; Sisson, W.G.; Brunson, R.R.

    1997-02-18T23:59:59.000Z

    The present invention provides a method for preparing irreversible linear aggregates (fibrils) of metal oxide powders by utilizing static or pulsed DC electrical fields across a relatively non-conducting liquid solvent in which organometal compounds or silicon alkoxides have been dissolved. The electric field is applied to the relatively non-conducting solution throughout the particle formation and growth process promoting the formation of either linear aggregates (fibrils) or spherical shaped particles as desired. Thus the present invention provides a physical method for altering the size, shape and porosity of precursor hydrous metal oxide or hydrous silicon oxide powders for the development of advanced ceramics with improved strength and insulating capacity. 3 figs.

  3. Comparison of monolith-supported metals for the direct oxidation of methane of syngas

    SciTech Connect (OSTI)

    Torniainen, P.M.; Chu, X.; Schmidt, L.D. (Univ. of Minnesota, Minneapolis (United States))

    1994-03-01T23:59:59.000Z

    The partial oxidation of CH[sub 4] in O[sub 2] near atmospheric pressure to produce syngas was investigated on monolith-supported Rh, Ni, Pt, Ir, Pd, Pd-La[sub 2]O[sub 3], Fe, Co, Re, and Ru catalysts in an autothermal flow reactor at residence times of [approximately]10 msec (GHSV [approximately] 100,000 hr[sup [minus]1]). Optimal CH[sub 4] conversion and CO and H[sub 2] selectivities of 0.89, 0.95, and 0.90, respectively, were achieved on Rh at 1000[angstrom]C with no loss in activity over many hours. Ni showed similar conversion and selectivities but deactivated. Experiments with up to 25 vol% H[sub 2]O added to the feed showed little evidence of the occurrence of steam reforming and water-gas shift reactions. Pt and Ir sustained stable reaction but a lower selectivities and conversion than Rh or Ni. Pd, Pd-La[sub 2]O[sub 3], and Co deactivated rapidly, while Re, Ru, and Fe would not sustain autothermal reaction. Ni and Re deactivated by volatilization and metal loss, while Pd-La[sub 2]O[sub 3] deactivated by carbon formation, and Pd deactivated by a combination of metal loss and carbon formation. Pd produced up to 14% selectivity to C[sub 2]H[sub 4] and C[sub 2]H[sub 4] and C[sub 2]H[sub 6], Pd-La[sub 2]O[sub 3] up to 5%, Pt [approximately] 1%, and other metals less than 0.2%. 10 refs., 5 figs., 1 tab.

  4. FINAL TECHNICAL REPORT Synthetic, Structural and Mechanistic Investigations of Olefin Polymerization Catalyzed by Early Transition Metal Compounds

    SciTech Connect (OSTI)

    Bercaw, John E. [California Institute of Technology

    2014-05-23T23:59:59.000Z

    The goal of this project is to develop new catalysts and provide understanding of ligand effects on catalyst composition in order to guide development of superior catalyst systems for polymerization of olefins. Our group is designing and synthesizing new “LX2”,“pincer” type ligands and complexing early transition metals to afford precatalysts. In a collaboration with Hans Brintzinger from the University of Konstanz, we are also examining the structures of the components of catalyst systems obtained from reaction of zirconocene dichlorides with aluminum alkyls and aluminum hydrides. Such systems are currently used commercially to produce polyolefins, but the nature of the active and dormant species as well as the mechanisms of their interconversions are not understood. New information on catalyst design and performance may lead to new types of polymers and/or new chemical transformations between hydrocarbons and transition metal centers, ultimately contributing to the development of catalytic reactions for the production of fuels, commodity and polymeric materials.

  5. Strain and electric field induced electronic properties of two-dimensional hybrid bilayers of transition-metal dichalcogenides

    SciTech Connect (OSTI)

    Sharma, Munish, E-mail: munishsharmahpu@live.com, E-mail: pk-ahluwalia7@yahoo.com; Kumar, Ashok; Ahluwalia, P. K., E-mail: munishsharmahpu@live.com, E-mail: pk-ahluwalia7@yahoo.com [Department of Physics, Himachal Pradesh University, Shimla 171005 (India); Pandey, Ravindra [Department of Physics, Michigan Technological University, Houghton, Michigan 49931 (United States)

    2014-08-14T23:59:59.000Z

    Tunability of the electronic properties of two-dimensional bilayer hetero structures of transition-metal dichalcogenides (i.e., MX{sub 2}-M?X?{sub 2} with (M, M??=?Mo, W; X, X??=?S, Se) is investigated. Application of both strain and electric field is found to modify the band gap and carrier effective mass in the hybrid bilayers considered. The calculated results based on density functional theory suggest that the tensile strain considerably changes the band gap of semiconducting bilayers; it makes the band gap to be indirect, and later initiates the semiconductor-to-metal transition. Application of the external electric fields, on the other hand, shows asymmetric variation in the band gap leading to the closure of the gap at about 0.5–1.0?V/Å. Tuning of the band gap and carrier effective mass in such a controlled manner makes the hybrid bilayers of transition metal dichalcogenides to be promising candidates for application in electronic devices at nanoscale.

  6. PHYSICAL REVIEW B 83, 115329 (2011) Diffusion and interface growth in hafnium oxide and silicate ultrathin films on Si(001)

    E-Print Network [OSTI]

    Garfunkel, Eric

    PHYSICAL REVIEW B 83, 115329 (2011) Diffusion and interface growth in hafnium oxide and silicate­oxide­semiconductor (CMOS) technology necessary.1,2 Transition metal (Hf, Zr, La) oxides, silicates, and ternary Hf to be desirable to have at least one monolayer of SiO2 at the dielectric/Si interface. The Hf oxide (silicate

  7. Soluble transition metals cause the pro-inflammatory effects of welding fumes in vitro 

    E-Print Network [OSTI]

    McNeilly, Jane D; Heal, Mathew R; Beverland, Iain J; Howe, Alan; Gibson, Mark D; Hibbs, Leon; MacNee, William; Donaldson, Ken

    2004-01-01T23:59:59.000Z

    Epidemiological studies have consistently reported a higher incidence of respiratory illnesses such as bronchitis, metal fume fever (MFF), and chronic pneumonitis among welders exposed to high concentrations of metal-enriched ...

  8. High-Temperature Zirconia Oxygen Sensor with Sealed Metal/Metal...

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

    High-Temperature Zirconia Oxygen Sensor with Sealed MetalMetal Oxide Internal Reference High-Temperature Zirconia Oxygen Sensor with Sealed MetalMetal Oxide Internal Reference...

  9. Probing the structural dependency of photoinduced properties of colloidal quantum dots using metal-oxide photo-active substrates

    SciTech Connect (OSTI)

    Patty, Kira; Campbell, Quinn; Hamilton, Nathan; West, Robert G. [Department of Physics, University of Alabama in Huntsville, Huntsville, Alabama 35899 (United States); Sadeghi, Seyed M., E-mail: seyed.sadeghi@uah.edu [Department of Physics, University of Alabama in Huntsville, Huntsville, Alabama 35899 (United States); Nano and Micro Device Center, University of Alabama in Huntsville, Huntsville, Alabama 35899 (United States); Mao, Chuanbin [Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, Norman, Oklahoma 73019 (United States)

    2014-09-21T23:59:59.000Z

    We used photoactive substrates consisting of about 1 nm coating of a metal oxide on glass substrates to investigate the impact of the structures of colloidal quantum dots on their photophysical and photochemical properties. We showed during irradiation these substrates can interact uniquely with such quantum dots, inducing distinct forms of photo-induced processes when they have different cores, shells, or ligands. In particular, our results showed that for certain types of core-shell quantum dot structures an ultrathin layer of a metal oxide can reduce suppression of quantum efficiency of the quantum dots happening when they undergo extensive photo-oxidation. This suggests the possibility of shrinking the sizes of quantum dots without significant enhancement of their non-radiative decay rates. We show that such quantum dots are not influenced significantly by Coulomb blockade or photoionization, while those without a shell can undergo a large amount of photo-induced fluorescence enhancement via such blockade when they are in touch with the metal oxide.

  10. Ultraviolet GaN photodetectors on Si via oxide buffer heterostructures with integrated short period oxide-based distributed Bragg reflectors and leakage suppressing metal-oxide-semiconductor contacts

    SciTech Connect (OSTI)

    Szyszka, A., E-mail: szyszka@ihp-microelectronics.com, E-mail: adam.szyszka@pwr.wroc.pl [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Faculty of Microsystem Electronics and Photonics, Wroclaw University of Technology, Janiszewskiego 11/17, 50-372 Wroclaw (Poland); Lupina, L.; Lupina, G.; Schubert, M. A.; Zaumseil, P. [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Haeberlen, M.; Storck, P.; Thapa, S. B. [Siltronic, Hanns-Seidel-Platz 4, 81737 München (Germany); Schroeder, T. [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); BTU Cottbus-Senftenberg, Konrad-Zuse-Strasse 1, 03046 Cottbus (Germany)

    2014-08-28T23:59:59.000Z

    Based on a novel double step oxide buffer heterostructure approach for GaN integration on Si, we present an optimized Metal-Semiconductor-Metal (MSM)-based Ultraviolet (UV) GaN photodetector system with integrated short-period (oxide/Si) Distributed Bragg Reflector (DBR) and leakage suppressing Metal-Oxide-Semiconductor (MOS) electrode contacts. In terms of structural properties, it is demonstrated by in-situ reflection high energy electron diffraction and transmission electron microscopy-energy dispersive x-ray studies that the DBR heterostructure layers grow with high thickness homogeneity and sharp interface structures sufficient for UV applications; only minor Si diffusion into the Y{sub 2}O{sub 3} films is detected under the applied thermal growth budget. As revealed by comparative high resolution x-ray diffraction studies on GaN/oxide buffer/Si systems with and without DBR systems, the final GaN layer structure quality is not significantly influenced by the growth of the integrated DBR heterostructure. In terms of optoelectronic properties, it is demonstrated that—with respect to the basic GaN/oxide/Si system without DBR—the insertion of (a) the DBR heterostructures and (b) dark current suppressing MOS contacts enhances the photoresponsivity below the GaN band-gap related UV cut-off energy by almost up to two orders of magnitude. Given the in-situ oxide passivation capability of grown GaN surfaces and the one order of magnitude lower number of superlattice layers in case of higher refractive index contrast (oxide/Si) systems with respect to classical III-N DBR superlattices, virtual GaN substrates on Si via functional oxide buffer systems are thus a promising robust approach for future GaN-based UV detector technologies.

  11. Measuring the Kernel of Time-Dependent Density Functional Theory with X-Ray Absorption Spectroscopy of 3d Transition Metals

    E-Print Network [OSTI]

    Gross, E.K.U.

    of 3d Transition Metals A. Scherz,* E. K. U. Gross, H. Appel, C. Sorg, K. Baberschke, and H. Wende, and a new approximation suggested. But the true value of DFT is in constructing one XC approxi- mation

  12. Ultra-stable Molecule-Surface Architectures at Metal Oxides: Structure, Bonding, and Electron-transfer Processes

    SciTech Connect (OSTI)

    Hamers, Robert John

    2013-12-07T23:59:59.000Z

    Research funded by this project focused on the development of improved strategies for functionalization of metal oxides to enhance charge?transfer processes relevant to solar energy conversion. Initial studies included Fe2O3, WO3, TiO2, SnO2, and ZnO as model oxide systems; these systems were chosen due to differences in metal oxidation state and chemical bonding types in these oxides. Later studies focused largely on SnO2 and ZnO, as these materials show particularly promising surface chemistry, have high electron mobility, and can be readily grown in both spherical nanoparticles and as elongated nanorods. New molecules were synthesized that allowed the direct chemical assembly of novel nanoparticle ?dyadic? structures in which two different oxide materials are chemically joined, leading to an interface that enhances the separation of of charge upon illumination. We demonstrated that such junctions enhance photocatalytic efficiency using model organic compounds. A separate effort focused on novel approaches to linking dye molecules to SnO2 and ZnO as a way to enhance solar conversion efficiency. A novel type of surface binding through

  13. REFORMULATION OF COAL-DERIVED TRANSPORTATION FUELS: SELECTIVE OXIDATION OF CARBON MONOXIDE ON METAL FOAM CATALYSTS

    SciTech Connect (OSTI)

    Mr. Paul Chin; Dr. Xiaolei Sun; Professor George W. Roberts; Professor James J. Spivey; Mr. Amornmart Sirijarhuphan; Dr. James G. Goodwin, Jr.; Dr. Richard W. Rice

    2002-12-31T23:59:59.000Z

    Several different catalytic reactions must be carried out in order to convert hydrocarbons (or alcohols) into hydrogen for use as a fuel for polyelectrolyte membrane (PEM) fuel cells. Each reaction in the fuel-processing sequence has a different set of characteristics, which influences the type of catalyst support that should be used for that particular reaction. A wide range of supports are being evaluated for the various reactions in the fuel-processing scheme, including porous and non-porous particles, ceramic and metal straight-channel monoliths, and ceramic and metal monolithic foams. These different types of support have distinctly different transport characteristics. The best choice of support for a given reaction will depend on the design constraints for the system, e.g., allowable pressure drop, and on the characteristics of the reaction for which the catalyst is being designed. Three of the most important reaction characteristics are the intrinsic reaction rate, the exothermicity/endothermicity of the reaction, and the nature of the reaction network, e.g., whether more than one reaction takes place and, in the case of multiple reactions, the configuration of the network. Isotopic transient kinetic analysis was used to study the surface intermediates. The preferential oxidation of low concentrations of carbon monoxide in the presence of high concentrations of hydrogen (PROX) is an important final step in most fuel processor designs. Data on the behavior of straight-channel monoliths and foam monolith supports will be presented to illustrate some of the factors involved in choosing a support for this reaction.

  14. Interface Engineering for Oxide Electronics: Tuning electronic properties by atomically controlled growth

    E-Print Network [OSTI]

    Twente, Universiteit

    ....................................................... 8 2.3.2 Metal-insulator phenomena in 3d transition-metal oxides ........................ 9 2 image of the pulsed laser deposition process with reflection high-energy electron diffraction monitoring-365-2351-6 Printed by Wöhrmann Print Service, The Netherlands © M. Huijben, 2006 #12;INTERFACE ENGINEERING FOR OXIDE

  15. Doped palladium containing oxidation catalysts

    DOE Patents [OSTI]

    Mohajeri, Nahid

    2014-02-18T23:59:59.000Z

    A supported oxidation catalyst includes a support having a metal oxide or metal salt, and mixed metal particles thereon. The mixed metal particles include first particles including a palladium compound, and second particles including a precious metal group (PMG) metal or PMG metal compound, wherein the PMG metal is not palladium. The oxidation catalyst may also be used as a gas sensor.

  16. A correlation between the heavy element content of transiting extrasolar planets and the metallicity of their parent stars

    E-Print Network [OSTI]

    Tristan Guillot; Nuno C. Santos; Frédéric Pont; Nicolas Iro; Claudio Melo; Ignasi Ribas

    2006-05-31T23:59:59.000Z

    Nine extrasolar planets with masses between 110 and 430M are known to transit their star. The knowledge of their masses and radii allows an estimate of their composition, but uncertainties on equations of state, opacities and possible missing energy sources imply that only inaccurate constraints can be derived when considering each planet separately. Aims: We seek to better understand the composition of transiting extrasolar planets by considering them as an ensemble, and by comparing the obtained planetary properties to that of the parent stars. Methods: We use evolution models and constraints on the stellar ages to derive the mass of heavy elements present in the planets. Possible additional energy sources like tidal dissipation due to an inclined orbit or to downward kinetic energy transport are considered. Results: We show that the nine transiting planets discovered so far belong to a quite homogeneous ensemble that is characterized by a mass of heavy elements that is a relatively steep function of the stellar metallicity, from less than 20 earth masses of heavy elements around solar composition stars, to up to 100M for three times the solar metallicity (the precise values being model-dependant). The correlation is still to be ascertained however. Statistical tests imply a worst-case 1/3 probability of a false positive. Conclusions: Together with the observed lack of giant planets in close orbits around metal-poor stars, these results appear to imply that heavy elements play a key role in the formation of close-in giant planets. The large masses of heavy elements inferred for planets orbiting metal rich stars was not anticipated by planet formation models and shows the need for alternative theories including migration and subsequent collection of planetesimals.

  17. Close-To-Practice Assessment Of Meat Freshness With Metal Oxide Sensor Microarray Electronic Nose

    SciTech Connect (OSTI)

    Musatov, V. Yu.; Sysoev, V. V. [Saratov State Technical University, ul. Polytechnicheskaya 77, 410054 Saratov (Russian Federation); Sommer, M.; Kiselev, I. [Forschungszentrum Karlsruhe, IMT, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2009-05-23T23:59:59.000Z

    In this report we estimate the ability of KAMINA e-nose, based on a metal oxide sensor (MOS) microarray and Linear Discriminant Analysis (LDA) pattern recognition, to evaluate meat freshness. The received results show that, 1) one or two exposures of standard meat samples to the e-nose are enough for the instrument to recognize the fresh meat prepared by the same supplier with 100% probability; 2) the meat samples of two kinds, stored at 4 deg. C and 25 deg. C, are mutually recognized at early stages of decay with the help of the LDA model built independently under the e-nose training to each kind of meat; 3) the 3-4 training cycles of exposure to meat from different suppliers are necessary for the e-nose to build a reliable LDA model accounting for the supplier factor. This study approves that the MOS e-nose is ready to be currently utilised in food industry for evaluation of product freshness. The e-nose performance is characterized by low training cost, a confident recognition power of various product decay conditions and easy adjustment to changing conditions.

  18. Interaction of coal-derived synthesis gas impurities with solid oxide fuel cell metallic components

    SciTech Connect (OSTI)

    Marina, Olga A.; Pederson, Larry R.; Coyle, Christopher A.; Edwards, Danny J.; Chou, Y. S.; Cramer, Carolyn N.

    2010-05-28T23:59:59.000Z

    Chromium-containing iron-based alloys Crofer22 APU and SS 441 and nickel-based alloy Inconel600, all commonly used in a solid oxide fuel cell (SOFC) stack as interconnect materials, heat exchanger and gas feeding pipes, were exposed at 700-850oC to a synthetic coal gas containing ?2 ppm phosphine, arsine, sulfur and antimony. Samples were characterized by SEM/EDS and XRD to monitor the secondary phase formation. Exposure of ferritic stainless steels to P led to the formation of surface Cr-Mn-P-O and Fe-P-O compounds and increased temperatures accelerated the rate of interactions. Fewer interactions were observed after exposures to As and Sb. No sulfur containing compounds were found. Nickel-based alloy exhibited much stronger interactions with As and P in comparison with ferritic steels and the arsenic interactions were particularly strong. The difference between the iron- and nickel-based alloys is explained by the different chemistry and morphology of the scales grown on the alloy surfaces in coal gas. While P and As interactions with the metallic parts in the SOFC are likely to mitigate the nickel/zirconia anode poisoning, the other degradation mechanisms should be taken into consideration to avoid potential stack failures. Manganese spinels were found to be effective as phosphorus getters and could be used in coal gas cleanup.

  19. Synthesis of Metal Oxide Nanomaterials for Chemical Sensors by Molecular Beam Epitaxy

    SciTech Connect (OSTI)

    Nandasiri, Manjula I.; Kuchibhatla, Satyanarayana V N T; Thevuthasan, Suntharampillai

    2013-12-01T23:59:59.000Z

    Since the industrial revolution, detection and monitoring of toxic matter, chemical wastes, and air pollutants has become an important environmental issue. Thus, it leads to the development of chemical sensors for various environmental applications. The recent disastrous oil spills over the near-surface of ocean due to the offshore drilling emphasize the use of chemical sensors for prevention and monitoring of the processes that might lead to these mishaps.1, 2 Chemical sensors operated on a simple principle that the sensing platform undergoes a detectable change when exposed to the target substance to be sensed. Among all the types of chemical sensors, solid state gas sensors have attracted a great deal of attention due to their advantages such as high sensitivity, greater selectivity, portability, high stability and low cost.3, 4 Especially, semiconducting metal oxides such as SnO2, TiO2, and WO3 have been widely used as the active sensing platforms in solid state gas sensors.5 For the enhanced properties of solid state gas sensors, finding new sensing materials or development of existing materials will be needed. Thus, nanostructured materials such as nanotubes,6-8 nanowires,9-11 nanorods,12-15 nanobelts,16, 17 and nano-scale thin films18-23 have been synthesized and studied for chemical sensing applications.

  20. Final LDRD report : metal oxide films, nanostructures, and heterostructures for solar hydrogen production.

    SciTech Connect (OSTI)

    Kronawitter, Coleman X. [Lawrence Berkeley National Laboratory, Berkeley, CA; Antoun, Bonnie R.; Mao, Samuel S. [Lawrence Berkeley National Laboratory, Berkeley, CA

    2012-01-01T23:59:59.000Z

    The distinction between electricity and fuel use in analyses of global power consumption statistics highlights the critical importance of establishing efficient synthesis techniques for solar fuels-those chemicals whose bond energies are obtained through conversion processes driven by solar energy. Photoelectrochemical (PEC) processes show potential for the production of solar fuels because of their demonstrated versatility in facilitating optoelectronic and chemical conversion processes. Tandem PEC-photovoltaic modular configurations for the generation of hydrogen from water and sunlight (solar water splitting) provide an opportunity to develop a low-cost and efficient energy conversion scheme. The critical component in devices of this type is the PEC photoelectrode, which must be optically absorptive, chemically stable, and possess the required electronic band alignment with the electrochemical scale for its charge carriers to have sufficient potential to drive the hydrogen and oxygen evolution reactions. After many decades of investigation, the primary technological obstacle remains the development of photoelectrode structures capable of efficient conversion of light with visible frequencies, which is abundant in the solar spectrum. Metal oxides represent one of the few material classes that can be made photoactive and remain stable to perform the required functions.

  1. Investigation of Some Transparent Metal Oxides as Damp Heat Protective Coating for CIGS Solar Cells: Preprint

    SciTech Connect (OSTI)

    Pern, F. J.; Yan, F.; Zaaunbrecher, B.; To, B.; Perkins, J.; Noufi, R.

    2012-10-01T23:59:59.000Z

    We investigated the protective effectiveness of some transparent metal oxides (TMO) on CIGS solar cell coupons against damp heat (DH) exposure at 85oC and 85% relative humidity (RH). Sputter-deposited bilayer ZnO (BZO) with up to 0.5-um Al-doped ZnO (AZO) layer and 0.2-um bilayer InZnO were used as 'inherent' part of device structure on CdS/CIGS/Mo/SLG. Sputter-deposited 0.2-um ZnSnO and atomic layer deposited (ALD) 0.1-um Al2O3 were used as overcoat on typical BZO/CdS/CIGS/Mo/SLG solar cells. The results were all negative -- all TMO-coated CIGS cells exhibited substantial degradation in DH. Combining the optical photographs, PL and EL imaging, SEM surface micro-morphology, coupled with XRD, I-V and QE measurements, the causes of the device degradations are attributed to hydrolytic corrosion, flaking, micro-cracking, and delamination induced by the DH moisture. Mechanical stress and decrease in crystallinity (grain size effect) could be additional degrading factors for thicker AZO grown on CdS/CIGS.

  2. Trending: Metal Oxo Bonds

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

    including materials science, chemistry, and biology. Highly covalent metal-oxygen multiple bonds (metal oxos) are the building blocks of metal oxides and have a bearing...

  3. Improved Modeling of Transition Metals, Applications to Catalysis and Technetium Chemistry

    SciTech Connect (OSTI)

    Cundari, T. R.

    2004-03-05T23:59:59.000Z

    There is considerable impetus for identification of aqueous OM catalysts as water is the ultimate ''green'' solvent. In collaboration with researchers at Ames Lab, we investigated effective fragment and Monte Carlo techniques for aqueous-phase hydroformylation (HyF). The Rh of the HyF catalyst is weakly aquated, in contrast to the hydride of the Rh-H bond. As the insertion of the olefin C=C into Rh-H determines the linear-to-branched aldehyde ratio, it is reasonable to infer that solvent plays an important role in regiochemistry. Studies on aqueous-phase organometallic catalysis were complemented in studies of the gas-phase reaction. A Rh-carbonyl-phosphine catalyst was investigated. Two of the most important implications of this research include (a) pseudorotation among five-coordinate intermediates is significant in HyF, and (b) CO insertion is the rate-determining step. The latter is in contrast to experimental deductions, highlighting the need for more accurate modeling. To this end, we undertook studies of (a) experimentally relevant PR{sub 3} co-ligands (PMe{sub 3}, PPh{sub 3}, P(p-PhSO{sub 3{sup -}}){sub 3}, etc.), and (b) HyF of propene. For the propylene research, simulations indicated that the linear: branched aldehyde ratio (linear is more desirable) is determined by thermodynamic discrimination of two distinct pathways. Other projects include a theory-experiment study of C-H activation by early transition metal systems, which establishes that weakly-bound adducts play a key role in activity selectivity. By extension, more selective catalysts for functionalization of methane (major component of natural gas) will require better understanding of these adducts, which are greatly affected by steric interactions with the ligands. In the de novo design of Tc complexes, we constructed (and are now testing) a coupled quantum mechanics-molecular mechanics protocol. Initial research shows it to be capable of accurately predicting structure ''from scratch.'' Challenges include conformational, geometric, coordination, spin, and particularly linkage (e.g., Tc-SCN versus Tc-NCS) isomerism. In general, our protocol can rapidly (<1 day with desktop software/hardware) predict the structure of diverse Tc complexes with an accuracy commensurate to organics. Our de novo strategy is also being used to investigate tris-pyrazolyl borate (Tp) complexes. Data suggests a fundamental difference in methane activation between TpRe and related CpRe complexes. Furthermore, Tp is a more electronically ''flexible'' platform for catalysts modification than Cp.

  4. Synthesis and characterization of nanostructured transition metal oxides for energy storage devices

    E-Print Network [OSTI]

    Kim, Jong Woung

    2012-01-01T23:59:59.000Z

    A new mechanism for high rate lithium-ion storage throughresearch of Nb 2 O 5 as a lithium-ion battery electrode andhas been incorporated in 2 V lithium-ion secondary batteries

  5. Improved layered mixed transition metal oxides for Li-ion batteries

    E-Print Network [OSTI]

    Doeff, Marca M.

    2010-01-01T23:59:59.000Z

    M n , ^ for Advanced Lithium-Ion Batteries," J. Electrochem.of LiCoi/3Nii/ Mn 02 for lithium-ion batteries," Chem.Mni/ 0 for advanced lithium-ion batteries," J. Power

  6. Improved layered mixed transition metal oxides for Li-ion batteries

    E-Print Network [OSTI]

    Doeff, Marca M.

    2010-01-01T23:59:59.000Z

    for rechargeable lithium batteries," Science 311(5763), 977-^ for Advanced Lithium-Ion Batteries," J. Electrochem. Soc.02 for lithium-ion batteries," Chem. Lett. , [3] Yabuuchi,

  7. Finding Room for Improvement in Transition Metal Oxides Cathodes for Lithium-ion Batteries

    E-Print Network [OSTI]

    Kam, Kinson

    2012-01-01T23:59:59.000Z

    Cathodes for Lithium-ion Batteries Kinson C. Kam and Marcarechargeable lithium-ion batteries has become an integral

  8. Synthesis and characterization of nanostructured transition metal oxides for energy storage devices

    E-Print Network [OSTI]

    Kim, Jong Woung

    2012-01-01T23:59:59.000Z

    insertion and is also electrochromic. These studies led toelectrode and as an electrochromic window. Lithium insertionone of the best inorganic electrochromic materials. [13] The

  9. Improved layered mixed transition metal oxides for Li-ion batteries

    E-Print Network [OSTI]

    Doeff, Marca M.

    2010-01-01T23:59:59.000Z

    for rechargeable lithium batteries," Science 311 (5763),for rechargeable lithium batteries," Science 311(5763), 977-M n , ^ for Advanced Lithium-Ion Batteries," J. Electrochem.

  10. Synthesis and characterization of nanostructured transition metal oxides for energy storage devices

    E-Print Network [OSTI]

    Kim, Jong Woung

    2012-01-01T23:59:59.000Z

    capacitors (also called supercapacitors). The limitations oflow power density while supercapacitors have low energycompared to those for supercapacitors. In this chapter, the

  11. Synthesis and characterization of nanostructured transition metal oxides for energy storage devices

    E-Print Network [OSTI]

    Kim, Jong Woung

    2012-01-01T23:59:59.000Z

    finding a promising supercapacitor material, (2) developingbeen applied to supercapacitor materials, even though it has

  12. Synthesis and characterization of nanostructured transition metal oxides for energy storage devices

    E-Print Network [OSTI]

    Kim, Jong Woung

    2012-01-01T23:59:59.000Z

    Figure 1.1. Ragone plot of various energy storage systems [issues for future energy storage systems. This dissertationin technology and energy storage has become the limiting

  13. Synthesis and characterization of nanostructured transition metal oxides for energy storage devices

    E-Print Network [OSTI]

    Kim, Jong Woung

    2012-01-01T23:59:59.000Z

    limit of commercial energy storage technology comprised ofimprovements in technology and energy storage has become theenergy storage devices. In particular, current technologies

  14. Accurate Band-Structure Calculations for the 3d Transition Metal Oxides

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisiting the TWP TWP Related LinksATHENA Account Information AccountsAccounts

  15. Thermodynamic Investigations of Lithium- and Manganese-Rich Transition Metal Oxides

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn'tOriginEducationVideoStrategic|Industrial Sector,Department of Energythe Use of Lowand Their

  16. Nanoparticles as Reactive Precursors: Synthesis of Alloys, Intermetallic Compounds, and Multi-Metal Oxides Through Low-Temperature Annealing and Conversion Chemistry 

    E-Print Network [OSTI]

    Bauer, John C.

    2010-07-14T23:59:59.000Z

    Alloys, intermetallic compounds and multi-metal oxides are generally made by traditional solid-state methods that often require melting or grinding/pressing powders followed by high temperature annealing (> 1000 degrees ...

  17. Method of depositing an electrically conductive oxide film on a textured metallic substrate and articles formed therefrom

    DOE Patents [OSTI]

    Christen, David K. (Oak Ridge, TN); He, Qing (Bloomington, MN)

    2003-04-29T23:59:59.000Z

    The present invention provides a biaxially textured laminate article having a polycrystalline biaxially textured metallic substrate with an electrically conductive oxide layer epitaxially deposited thereon and methods for producing same. In one embodiment a biaxially texture Ni substrate has a layer of LaNiO.sub.3 deposited thereon. An initial layer of electrically conductive oxide buffer is epitaxially deposited using a sputtering technique using a sputtering gas which is an inert or forming gas. A subsequent layer of an electrically conductive oxide layer is then epitaxially deposited onto the initial layer using a sputtering gas comprising oxygen. The present invention will enable the formation of biaxially textured devices which include HTS wires and interconnects, large area or long length ferromagnetic and/or ferroelectric memory devices, large area or long length, flexible light emitting semiconductors, ferroelectric tapes, and electrodes.

  18. Method of depositing an electrically conductive oxide film on a textured metallic substrate and articles formed therefrom

    DOE Patents [OSTI]

    Christen, David K. (Oak Ridge, TN); He, Qing (Bloomington, MN)

    2001-01-01T23:59:59.000Z

    The present invention provides a biaxially textured laminate article having a polycrystalline biaxially textured metallic substrate with an electrically conductive oxide layer epitaxially deposited thereon and methods for producing same. In one embodiment a biaxially texture Ni substrate has a layer of LaNiO.sub.3 deposited thereon. An initial layer of electrically conductive oxide buffer is epitaxially deposited using a sputtering technique using a sputtering gas which is an inert or forming gas. A subsequent layer of an electrically conductive oxide layer is then epitaxially deposited onto the initial layer using a sputtering gas comprising oxygen. The present invention will enable the formation of biaxially textured devices which include HTS wires and interconnects, large area or long length ferromagnetic and/or ferroelectric memory devices, large area or long length, flexible light emitting semiconductors, ferroelectric tapes, and electrodes.

  19. Geochemical, metagenomic and metaproteomic insights into trace metal utilization by methane-oxidizing microbial consortia in sulfidic marine sediments

    SciTech Connect (OSTI)

    Glass, DR. Jennifer [California Institute of Technology, Pasadena; Yu, DR. Hang [California Institute of Technology, Pasadena; Steele, Joshua [California Institute of Technology, Pasadena; Dawson, Katherine [California Institute of Technology, Pasadena; Sun, S [University of California, San Diego; Chourey, Karuna [ORNL; Hettich, Robert {Bob} L [ORNL; Orphan, V [California Institute of Technology, Pasadena

    2014-01-01T23:59:59.000Z

    Microbes have obligate requirements for trace metals in metalloenzymes that catalyze important biogeochemical reactions. In anoxic methane- and sulfide-rich environments, microbes may have unique adaptations for metal acquisition and utilization due to decreased bioavailability as a result of metal sulfide precipitation. However, micronutrient cycling is largely unexplored in cold ( 10 C) and sulfidic (>1 mM H2S) deep-sea methane seep ecosystems. We investigated trace metal geochemistry and microbial metal utilization in methane seeps offshore Oregon and California, USA, and report dissolved concentrations of nickel (0.5-270 nM), cobalt (0.5-6 nM), molybdenum (10-5,600 nM) and tungsten (0.3-8 nM) in Hydrate Ridge sediment porewaters. Despite low levels of cobalt and tungsten, metagenomic and metaproteomic data suggest that microbial consortia catalyzing anaerobic oxidation of methane utilize both scarce micronutrients in addition to nickel and molybdenum. Genetic machinery for cobalt-containing vitamin B12 biosynthesis was present in both anaerobic methanotrophic archaea (ANME) and sulfate-reducing bacteria (SRB). Proteins affiliated with the tungsten-containing form of formylmethanofuran dehydrogenase were expressed in ANME from two seep ecosystems, the first evidence for expression of a tungstoenzyme in psychrotolerant microorganisms. Finally, our data suggest that chemical speciation of metals in highly sulfidic porewaters may exert a stronger influence on microbial bioavailability than total concentration

  20. Synthesis of Functionalized Superparamagnetic Iron Oxide Nanoparticles from a Common Precursor and their Application as Heavy Metal and Actinide Sorbents

    SciTech Connect (OSTI)

    Warner, Marvin G.; Warner, Cynthia L.; Addleman, Raymond S.; Droubay, Timothy C.; Engelhard, Mark H.; Davidson, Joseph D.; Cinson, Anthony D.; Nash, Michael A.; Yantasee, Wassana

    2009-10-12T23:59:59.000Z

    We describe the use of a simple and versatile technique to generate a series of ligand stabilized iron oxide nanoparticles containing different ? functionalities with specificities toward heavy metals and actinides at the periphery of the stabilizing ligand shell from a common, easy to synthesize precursor nanoparticle. The resulting nanoparticles are designed to contain affinity ligands that make them excellent sorbent materials for a variety of heavy metals from contaminated aqueous systems such as river water and ground water as well as actinides from clinical samples such as blood and urine. Functionalized superparamagnetic nanoparticles make ideal reagents for extraction of heavy metal and actinide contaminants from environmental and clinical samples since they are easily removed from the media once bound to the contaminant by simply applying a magnetic field. In addition, these engineered nanomaterials have an inherently high active surface area (often > 100 m2/g) making them ideal sorbent materials for these types of applications

  1. Schottky barrier height reduction for holes by Fermi level depinning using metal/nickel oxide/silicon contacts

    SciTech Connect (OSTI)

    Islam, Raisul, E-mail: raisul@stanford.edu; Shine, Gautam; Saraswat, Krishna C. [Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States)

    2014-11-03T23:59:59.000Z

    We report the experimental demonstration of Fermi level depinning using nickel oxide (NiO) as the insulator material in metal-insulator-semiconductor (M-I-S) contacts. Using this contact, we show less than 0.1?eV barrier height for holes in platinum/NiO/silicon (Pt/NiO/p-Si) contact. Overall, the pinning factor was improved from 0.08 (metal/Si) to 0.26 (metal/NiO/Si). The experimental results show good agreement with that obtained from theoretical calculation. NiO offers high conduction band offset and low valence band offset with Si. By reducing Schottky barrier height, this contact can be used as a carrier selective contact allowing hole transport but blocking electron transport, which is important for high efficiency in photonic applications such as photovoltaics and optical detectors.

  2. Electronic structure of perovskite oxide surfaces at elevated temperatures and its correlation with oxygen reduction reactivity

    E-Print Network [OSTI]

    Chen, Yan, Ph. D. Massachusetts Institute of Technology

    2014-01-01T23:59:59.000Z

    The objective is to understand the origin of the local oxygen reduction reaction (ORR) activity on the basis of the local electronic structure at the surface of transition metal oxides at elevated temperatures and in oxygen ...

  3. High Activity of Ce1-xNixO2-y for H2 Production through Ethanol Steam Reforming: Tuning Catalytic Performance through Metal-Oxide Interactions

    SciTech Connect (OSTI)

    G Zhou; L Barrio; S Agnoli; S Senanayake; J Evans; A Kubacka; M Estrella; J Hanson; A Martinez-Arias; et al.

    2011-12-31T23:59:59.000Z

    The importance of the oxide: Ce{sub 0.8}Ni{sub 0.2}O{sub 2-y} is an excellent catalyst for ethanol steam reforming. Metal-oxide interactions perturb the electronic properties of the small particles of metallic nickel present in the catalyst under the reaction conditions and thus suppress any methanation activity. The nickel embedded in ceria induces the formation of O vacancies, which facilitate cleavage of the OH bonds in ethanol and water.

  4. Enhancement of band-to-band tunneling in mono-layer transition metal dichalcogenides two-dimensional materials by vacancy defects

    SciTech Connect (OSTI)

    Jiang, Xiang-Wei; Li, Shu-Shen [State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Gong, Jian [School of Physics Science and Technology, Inner Mongolia University, Hohhot 010021 (China); Xu, Nuo [Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720 (United States); Zhang, Jinfeng; Hao, Yue [Key Laboratory of Wide Band Gap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi'an 710071 (China); Wang, Lin-Wang, E-mail: lwwang@lbl.gov [Material Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2014-01-13T23:59:59.000Z

    The band-to-band tunneling of monolayer transition metal dichalcogenides nano-junction is investigated using atomistic ab initio quantum transport simulations. From the simulation, it is found that the transition metal vacancy defect in the two-dimensional MX{sub 2} (M = Mo,W; X = S,Se) band-to-band tunneling diode can dramatically boost the on-state current up to 10 times while maintaining the device sub-threshold swing. The performance enhancement mechanism is discussed in detail by examining partial density of states of the system. It is found that the transition metal vacancy induces band-gap states, which reduce the effective length of the tunneling transition region.

  5. Trends in Methanol Decomposition on Transition Metal Alloy Clusters from Scaling and Brønsted–Evans–Polanyi Relationships

    SciTech Connect (OSTI)

    Mehmood, Faisal; Rankin, Rees B.; Greeley, Jeffrey P.; Curtiss, Larry A.

    2012-05-15T23:59:59.000Z

    A combination of ?rst principles Density Functional Theory calculations and thermochemical scaling relationships are employed to estimate the thermochemistry and kinetics of methanol decomposition on unsupported subnanometer metal clusters. The approach uses binding energies of various atomic and molecular species, determined on the pure metal clusters, to develop scaling relationships that are then further used to estimate the methanol decomposition thermodynamics for a series of pure and bimetallic clusters with four atoms per cluster. Additionally, activation energy barriers are estimated from Brønsted–Evans–Polanyi plots relating transition and ?nal state energies on these clusters. The energetic results are combined with a simple, microkineticallyinspired rate expression to estimate reaction rates as a function of important catalytic descriptors, including the carbon and atomic oxygen binding energies to the clusters. Based on these analyses, several alloy clusters are identi?ed as promising candidates for the methanol decomposition reaction.

  6. Femtosecond soft x-ray spectroscopy of solvated transition metal complexes: Deciphering the interplay of electronic and structural dynamics

    SciTech Connect (OSTI)

    Huse, Nils; Cho, Hana; Hong, Kiryong; Jamula, Lindsey; de Groot, Frank M. F.; Kim, Tae Kyu; McCusker, James K.; Schoenlein, Robert W.

    2011-03-09T23:59:59.000Z

    We present the first implementation of femtosecond soft X-ray spectroscopy as an ultrafast direct probe of the excited-state valence orbitals in solution-phase molecules. This method is applied to photoinduced spin crossover of [Fe(tren(py)3)]2+, where the ultrafast spinstate conversion of the metal ion, initiated by metal-to-ligand charge-transfer excitation, is directly measured using the intrinsic spin-state selectivity of the soft X-ray L-edge transitions. Our results provide important experimental data concerning the mechanism of ultrafast spin-state conversion and subsequent electronic and structural dynamics, highlighting the potential of this technique to study ultrafast phenomena in the solution phase.

  7. Semiconductor-metal phase transition of vanadium dioxide nanostructures on silicon substrate: Applications for thermal control of spacecraft

    SciTech Connect (OSTI)

    Leahu, G. L., E-mail: roberto.livoti@uniroma1.it; Li Voti, R., E-mail: roberto.livoti@uniroma1.it; Larciprete, M. C., E-mail: roberto.livoti@uniroma1.it; Belardini, A., E-mail: roberto.livoti@uniroma1.it; Mura, F., E-mail: roberto.livoti@uniroma1.it; Sibilia, C.; Bertolotti, M. [Dipartimento di Scienze di Base ed Applicate per l'Ingegneria, Sapienza Università di Roma, Via A. Scarpa 16 00161 Roma (Italy); Fratoddi, I. [Dipartimento di Chimica, Sapienza Università di Roma, Piazzale A. Moro, Roma (Italy)

    2014-06-19T23:59:59.000Z

    We present a detailed infrared study of the semiconductor-to-metal transition (SMT) in a vanadium dioxide (VO2) film deposited on silicon wafer. The VO2 phase transition is studied in the mid-infrared (MIR) region by analyzing the transmittance and the reflectance measurements, and the calculated emissivity. The temperature behaviour of the emissivity during the SMT put into evidence the phenomenon of the anomalous absorption in VO2 which has been explained by applying the Maxwell Garnett effective medium approximation theory, together with a strong hysteresis phenomenon, both useful to design tunable thermal devices to be applied for the thermal control of spacecraft. We have also applied the photothermal radiometry in order to study the changes in the modulated emissivity induced by laser. Experimental results show how the use of these techniques represent a good tool for a quantitative measurement of the optothermal properties of vanadium dioxide based structures.

  8. On the origin of the luminosity - metallicity relation for late-type galaxies: Spirals to irregulars transition

    E-Print Network [OSTI]

    L. S. Pilyugin; F. Ferrini

    2000-01-05T23:59:59.000Z

    We consider the roles of two widely invoked mechanisms for the metallicity-luminosity correlation among late-type galaxies: higher astration level and decreasing efficiency of heavy-element loss with increasing luminosity. We find that both mechanisms contribute about equally to the range in oxygen abundance between low (logL_B = 8) and high (logL_B = 10.5) luminosity galaxies. We also consider the transition from spirals to irregulars, finding that both the oxygen abundance deficiency (indicating the degree of mass exchange between a galaxy and its environment) and the gas fraction vary smoothly along the sequence. Thus we find no "irregular versus spiral dichotomy".

  9. Process for making whiskers, fibers and flakes of transition metal compounds

    DOE Patents [OSTI]

    Bamberger, C.E.

    1992-06-02T23:59:59.000Z

    A process for making titanium and chromium nitrides of known morphology by reacting potassium titanate and chromium oxide in the gas phase with NH[sub 3]. The products exhibit the same morphology as the starting material.

  10. Process for making whiskers, fibers and flakes of transition metal compounds

    DOE Patents [OSTI]

    Bamberger, Carlos E. (Oak Ridge, TN)

    1992-01-01T23:59:59.000Z

    A process for making titanium and chromium nitrides of known morphology by reacting potassium titanate and chromium oxide in the gas phase with NH.sub.3. The products exhibit the same morphology as the starting material.

  11. Removal of metal oxide defects through improved semi-anisotropic wet etching process

    E-Print Network [OSTI]

    Dave, Neha H. (Neha Hemang)

    2012-01-01T23:59:59.000Z

    Data recently collected from an industrial thin film manufacturer indicate that almost 8% of devices are rejected due to excess metal, or unwanted metal on the device surface. Experimentation and analysis suggest that ...

  12. Detecting Hazardous Gas Analytes Using Porous Silicon Sensors Coated with Metal Oxide Nanoparticles Eddie Goude, University of Florida Georgia Tech SURF 2011

    E-Print Network [OSTI]

    Li, Mo

    Detecting Hazardous Gas Analytes Using Porous Silicon Sensors Coated with Metal Oxide Nanoparticles oxide coatings and the Hard-Soft Acid-Base concept. This sensor is proposed to be a new, nanotechnology for this experiment, p-type and n-type. The wafers were first coated with silicon carbide and then etched with a mask

  13. E-Print Network 3.0 - alkali metal oxides Sample Search Results

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

    , sodium carbide, turpentine, finely divided metals Calcium water, carbon dioxide, carbon tetrachloride... , and chlorinated hydrocarbons Carbon, activated calcium...

  14. Retrograde melting in transition metal-silicon systems : thermodynamic modeling, experimental verification, and potential application

    E-Print Network [OSTI]

    Fenning, David P

    2010-01-01T23:59:59.000Z

    A theoretical framework is presented in this work for retrograde melting in silicon driven by the retrograde solubility of low-concentration metallic solutes at temperatures above the binary eutectic. High enthalpy of ...

  15. Support shape effect in metal oxide catalysis: ceria nanoshapes supported vanadia catalysts for oxidative dehydrogenation of iso-butane

    SciTech Connect (OSTI)

    Wu, Zili [ORNL; Schwartz, Viviane [ORNL; Li, Meijun [ORNL; Rondinone, Adam Justin [ORNL; Overbury, Steven {Steve} H [ORNL

    2012-01-01T23:59:59.000Z

    The activation energy of VOx/CeO2 catalysts in oxidative dehydrogenation of iso-butane was found dependent on the shape of ceria support: rods < octahedra, closely related to the surface oxygen vacancy formation energy and defects amount of the two ceria supports with different crystallographic surface planes.

  16. Optical and dielectric characteristics of the rare-earth metal oxide Lu{sub 2}O{sub 3}

    SciTech Connect (OSTI)

    Ordin, S. V., E-mail: stas_ordin@mail.ru; Shelykh, A. I. [Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation)

    2010-05-15T23:59:59.000Z

    The characteristics of the Lu{sub 2}O{sub 3} oxide and their variations controlled by compositional defects are studied. The defects are anion vacancies produced on partial reduction of the oxide. Such defects exhibit features typical of quantum objects and have a profound effect on the optical transmittance spectrum, the character of conduction (insulator or semiconductor properties) and the order of magnitude of the permittivity {epsilon} (capable of varying from 11.2 to 125). The structural features of vacancies in the oxides are considered, and the effect of vacancies on the polarization, conductivity, and lattice vibrations is studied. The studies are carried out in the temperature range 200-900 K, the wavelength range 0.03-50 {mu}m, and the current frequency range 10{sup 2}-10{sup 5} Hz. The rare-earth metal oxides attract interest for applications in microelectronics due to their high permittivity (several times higher than the permittivity of SiO{sub 2}) and, hence, the prospects for use of these oxides instead of SiO{sub 2}.

  17. Hydrolysis of Naptalam and Structurally Related Amides: Inhibition by Dissolved Metal Ions and Metal (Hydr)Oxide Surfaces

    E-Print Network [OSTI]

    Huang, Ching-Hua

    . INTRODUCTION Several important classes of agrochemicals possess amide and anilide functional groups. Naptalam). Agrochemicals often possess functional groups in the vicinity of amide and anilide linkages; participation and anilide agrochemicals. Granados et al. (1995) reported no significant effects of dissolved divalent metal

  18. Probing reaction dynamics of transition-metal complexes in solution via time-resolved soft x-ray spectroscopy

    SciTech Connect (OSTI)

    Huse, N.; Kim, T.-K.; Khalil, M.; Jamula, L.; McCusker, J.K.; Schoenlein, R.W.

    2008-08-01T23:59:59.000Z

    We report the first time-resolved soft x-ray measurements of solvated transition-metal complexes. L-edge spectroscopy directly probes dynamic changes in ligand-field splitting of 3d orbitals associated with the spin transition, and mediated by changes in ligand-bonding. We report the first time-resolved soft x-ray spectroscopy of solution-phase molecular dynamics. Changes in ligand-field splitting and spin-state populations in 3d orbitals of the Fe{sup II} complex are directly probed via transient absorption changes of the Fe L{sub 2} and L{sub 3} edges following photo-induced metal-to-ligand charge transfer. With the emergence of high-flux ultrafast soft x-ray sources, details on interplay between atomic structure, electronic states, and spin contributions will be revealed. Our experimental approach opens the door to femtosecond soft x-ray investigations of liquid phase chemistry that have previously been inaccessible.

  19. Compositional Control of Surface Oxides on Metal Alloys using Photons: Dynamic Simulations and Experiments

    SciTech Connect (OSTI)

    Chang, C.; Sankaranarayanan, S; Ruzmetov, D; Engelhard, M; Kaxiras, E; Ramanathan, S

    2010-01-01T23:59:59.000Z

    We report on the ability to modify the structure and composition of ultrathin oxides grown on Ni and Ni-Al alloy surfaces at room temperature utilizing photon illumination. We find that the nickel-oxide formation is enhanced in the case of oxidation under photo-excitation. The enhanced oxidation kinetics of nickel in 5% Ni-Al alloy is corroborated by experimental and simulation studies of natural and photon-assisted oxide growth on pure Ni(100) surfaces. In case of pure Ni substrates, combined x-ray photoelectron spectroscopy analysis, and atomic force microscope current mapping support the deterministic role of the structure of nickel passive-oxide films on their nanoscale corrosion resistance. Atomistic simulations involving dynamic charge transfer predict that the applied electric field overcomes the activation-energy barrier for ionic migration, leading to enhanced oxygen incorporation into the oxide, enabling us to tune the mixed-oxide composition at atomic length scales. Atomic scale control of ultrathin oxide structure and morphology in the case of pure substrates as well as compositional tuning of complex oxide in the case of alloys leads to excellent passivity as verified from potentiodynamic polarization experiments.

  20. Sub-Nanostructured Non Transition Metal Complex Grids for Hydrogen Storage

    SciTech Connect (OSTI)

    Dr. Orhan Talu; Dr. Surendra N. Tewari

    2007-10-27T23:59:59.000Z

    This project involved growing sub-nanostructured metal grids to increase dynamic hydrogen storage capacity of metal hydride systems. The nano particles of any material have unique properties unlike its bulk form. Nano-structuring metal hydride materials can result in: {sm_bullet}Increased hydrogen molecule dissociation rate, {sm_bullet} Increased hydrogen atom transport rate, {sm_bullet} Decreased decrepitation caused by cycling, {sm_bullet} Increased energy transfer in the metal matrix, {sm_bullet} Possible additional contribution by physical adsorption, and {sm_bullet} Possible additional contribution by quantum effects The project succeeded in making nano-structured palladium using electrochemical growth in templates including zeolites, mesoporous silica, polycarbonate films and anodized alumina. Other metals were used to fine-tune the synthesis procedures. Palladium was chosen to demonstrate the effects of nano-structuring since its bulk hydrogen storage capacity and kinetics are well known. Reduced project funding was not sufficient for complete characterization of these materials for hydrogen storage application. The project team intends to seek further funding in the future to complete the characterization of these materials for hydrogen storage.