Sample records for metal oxide semiconductor

  1. 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.

  2. E-Print Network 3.0 - active complementary metal-oxide-semiconductor...

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

    ion-implanted p and n dopants in germanium Summary: wavelength spectrum allowing optoelectronic integra- tion to enhance complementary-metal-oxide- semiconductor... lim- its in...

  3. E-Print Network 3.0 - area metal-oxide-semiconductor electron...

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

    inversion layer mobility Joo-Hiuk Son,a) Seongtae... measured absorption of terahertz radiation pulses by metal-oxide-semiconductor MOS inversion layers... of the...

  4. Transition metal oxides on organic semiconductors Yongbiao Zhao a

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    semiconductors (OSs) structure has been widely used in inverted organic optoelectronic devices, including toward in simplifying the fabrication process of the organic optoelectronic devices. Ã? 2014 Elsevier B], have gained great attention because of their wide applications in optoelectronic devices composed

  5. Fast 8 kV metal-oxide semiconductor field-effect transistor switch R. E. Continetti, D. R. Cyr,al and D. M. Neumarkb)

    E-Print Network [OSTI]

    Neumark, Daniel M.

    V. A key to this approach is the use of a metal-oxide varistor (MOV) to clamp the voltage acrossa givenFast 8 kV metal-oxide semiconductor field-effect transistor switch R. E. Continetti, D. R. Cyr transformer-isolatedpower metal-oxide semiconductor field-effect transistors in seriesis described

  6. Effects of anneals in ammonia on the interface trap density near the band edges in 4Hsilicon carbide metal-oxide-semiconductor capacitors

    E-Print Network [OSTI]

    Pantelides, Sokrates T.

    ­silicon carbide metal-oxide-semiconductor capacitors Gilyong Chung, Chin Che Tin, and John R. Williamsa) Physics. Silicon carbide is the only wide band gap semiconductor that has a native oxide, and metal temperature capacitance­voltage measurements are reported for SiO2/4H­SiC n and p type metal

  7. Interfacial oxide re-growth in thin film metal oxide III-V semiconductor systems

    SciTech Connect (OSTI)

    McDonnell, S.; Dong, H.; Hawkins, J. M.; Brennan, B.; Milojevic, M.; Aguirre-Tostado, F. S.; Zhernokletov, D. M.; Hinkle, C. L.; Kim, J.; Wallace, R. M.

    2012-04-02T23:59:59.000Z

    The Al{sub 2}O{sub 3}/GaAs and HfO{sub 2}/GaAs interfaces after atomic layer deposition are studied using in situ monochromatic x-ray photoelectron spectroscopy. Samples are deliberately exposed to atmospheric conditions and interfacial oxide re-growth is observed. The extent of this re-growth is found to depend on the dielectric material and the exposure temperature. Comparisons with previous studies show that ex situ characterization can result in misleading conclusions about the interface reactions occurring during the metal oxide deposition process.

  8. 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-effect transistors have been formed by incorporating barium strontium titanate (BST) deposited by rf magnetron in increased leakage. Due to its large dielectric constant, barium strontium ti- tanate [Ba1-xSrxTiO3, (BST

  9. Transient radiation hardened CMOS (complementary metal oxide semiconductor) operational amplifiers. Master's thesis

    SciTech Connect (OSTI)

    Trombley, G.J.

    1989-01-01T23:59:59.000Z

    General strategies are developed for designing radiation hardened bulk and silicon on insulator (SOI) complementary metal oxide semiconductor (CMOS) operational amplifiers. Comparisons are made between each technology concerning photocurrent mechanisms and the inherent advantages of SOI CMOS. Methods are presented for analysing circuit designs and minimizing the net photocurrent responses. Analysis is performed on standard operational amplifier circuits and subcircuits to demonstrate the usefulness of these methods. Radiation hardening topics discussed include superior radiation hardened topologies, photocurrent compensation and its limitations, and methods to ensure a preferred direction of photocurrent response. Several operational amplifier subcircuits are compared for their hardness characteristics. Folded cascode and three-stage operational amplifiers were fabricated on an SOI CMOS test chip supported by Texas Instruments, Incorporated. At the time of publication, the circuit operation was verified but radiation data were not yet available.

  10. Multichannel, time-resolved picosecond laser ultrasound imaging and spectroscopy with custom complementary metal-oxide-semiconductor detector

    SciTech Connect (OSTI)

    Smith, Richard J.; Light, Roger A.; Johnston, Nicholas S.; Pitter, Mark C.; Somekh, Mike G. [Institute of Biophysics, Imaging and Optical Science, University of Nottingham, Nottinghamshire NG7 2RD (United Kingdom); Sharples, Steve D. [Applied Optics Group, Electrical Systems and Optics Research Division, University of Nottingham, Nottinghamshire NG7 2RD (United Kingdom)

    2010-02-15T23:59:59.000Z

    This paper presents a multichannel, time-resolved picosecond laser ultrasound system that uses a custom complementary metal-oxide-semiconductor linear array detector. This novel sensor allows parallel phase-sensitive detection of very low contrast modulated signals with performance in each channel comparable to that of a discrete photodiode and a lock-in amplifier. Application of the instrument is demonstrated by parallelizing spatial measurements to produce two-dimensional thickness maps on a layered sample, and spectroscopic parallelization is demonstrated by presenting the measured Brillouin oscillations from a gallium arsenide wafer. This paper demonstrates the significant advantages of our approach to pump probe systems, especially picosecond ultrasonics.

  11. Characterization of Amorphous Zinc Tin Oxide Semiconductors....

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

    Amorphous Zinc Tin Oxide Semiconductors. Characterization of Amorphous Zinc Tin Oxide Semiconductors. Abstract: Amorphous zinc tin oxide (ZTO) was investigated to determine the...

  12. 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.

  13. Experimental study on vertical scaling of InAs-on-insulator metal-oxide-semiconductor field-effect transistors

    SciTech Connect (OSTI)

    Kim, SangHyeon, E-mail: dadembyora@mosfet.t.u-tokyo.ac.jp, E-mail: sh-kim@kist.re.kr; Yokoyama, Masafumi; Nakane, Ryosho; Takenaka, Mitsuru; Takagi, Shinichi [Department of Electrical Engineering and Information Systems, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Ichikawa, Osamu; Osada, Takenori; Hata, Masahiko [Sumitomo Chemical Co., Ltd., 6 Kitahara, Tsukuba, Ibaraki 300-3294 (Japan)

    2014-06-30T23:59:59.000Z

    We have investigated effects of the vertical scaling on electrical properties in extremely thin-body InAs-on-insulator (-OI) metal-oxide-semiconductor field-effect transistors (MOSFETs). It is found that the body thickness (T{sub body}) scaling provides better short channel effect (SCE) control, whereas the T{sub body} scaling also causes the reduction of the mobility limited by channel thickness fluctuation (?T{sub body}) scattering (?{sub fluctuation}). Also, in order to achieve better SCEs control, the thickness of InAs channel layer (T{sub channel}) scaling is more favorable than the thickness of MOS interface buffer layer (T{sub buffer}) scaling from a viewpoint of a balance between SCEs control and ?{sub fluctuation} reduction. These results indicate necessity of quantum well channel structure in InAs-OI MOSFETs and these should be considered in future transistor design.

  14. Investigation on edge fringing effect and oxide thickness dependence of inversion current in metal-oxide-semiconductor tunneling diodes with comb-shaped electrodes

    SciTech Connect (OSTI)

    Lin, Chien-Chih; Hsu, Pei-Lun; Lin, Li; Hwu, Jenn-Gwo, E-mail: jghwu@ntu.edu.tw [Graduate Institute of Electronics Engineering, Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan (China)

    2014-03-28T23:59:59.000Z

    A particular edge-dependent inversion current behavior of metal-oxide-semiconductor (MOS) tunneling diodes was investigated utilizing square and comb-shaped electrodes. The inversion tunneling current exhibits the strong dependence on the tooth size of comb-shaped electrodes and oxide thickness. Detailed illustrations of current conduction mechanism are developed by simulation and experimental measurement results. It is found that the electron diffusion current and Schottky barrier height lowering for hole tunneling current both contribute on inversion current conduction. In MOS tunneling photodiode applications, the photoresponse can be improved by decreasing SiO{sub 2} thickness and using comb-shaped electrodes with smaller tooth spacing. Meantime, the high and steady photosensitivity can also be approached by introducing HfO{sub 2} into dielectric stacks.

  15. Direct observation of both contact and remote oxygen scavenging of GeO{sub 2} in a metal-oxide-semiconductor stack

    SciTech Connect (OSTI)

    Fadida, S., E-mail: sivanfa@tx.technion.ac.il; Shekhter, P.; Eizenberg, M. [Department of Materials Science and Engineering, Technion-Israel Institute of Technology, Haifa (Israel); Cvetko, D. [Laboratorio TASC/IOM-CNR, Area di ricerca, Trieste (Italy); Department of Physics, Faculty of Mathematics and Physics, University of Ljubljana, Ljubljana (Slovenia); Floreano, L.; Verdini, A. [Laboratorio TASC/IOM-CNR, Area di ricerca, Trieste (Italy); Nyns, L.; Van Elshocht, S. [Imec, Kapeldreef 75, B-3001 Leuven (Belgium); Kymissis, I. [Department of Electrical Engineering, Columbia University, New York, New York 10027 (United States)

    2014-10-28T23:59:59.000Z

    In the path to incorporating Ge based metal-oxide-semiconductor into modern nano-electronics, one of the main issues is the oxide-semiconductor interface quality. Here, the reactivity of Ti on Ge stacks and the scavenging effect of Ti were studied using synchrotron X-ray photoelectron spectroscopy measurements, with an in-situ metal deposition and high resolution transmission electron microscopy imaging. Oxygen removal from the Ge surface was observed both in direct contact as well as remotely through an Al{sub 2}O{sub 3} layer. The scavenging effect was studied in situ at room temperature and after annealing. We find that the reactivity of Ti can be utilized for improved scaling of Ge based devices.

  16. Ferromagnetism in Oxide Semiconductors

    SciTech Connect (OSTI)

    Chambers, Scott A.; Droubay, Timothy C.; Wang, Chong M.; Rosso, Kevin M.; Heald, Steve M.; Schwartz, S. A.; Kittilstved, Kevin R.; Gamelin, Daniel R.

    2006-11-01T23:59:59.000Z

    In order to become a practical technology, semiconductor spintronics requires the discovery and utilization of ferromagnetic semiconductors which exhibit spin polarization in the majority carrier band at and above room temperature. Intrinsic remanent magnetization would allow spin polarized currents to be propagated in such materials without the need for a continuous magnetic field. However, the discovery and understanding of such materials is proving to be a grand challenge in solid-state science. Indeed, one of the 125 critical unanswered scientific questions recently posed in Science magazine asks, “Is it possible to create magnetic semiconductors that work at room temperature?”

  17. Selective CO{sub 2} reduction conjugated with H{sub 2}O oxidation utilizing semiconductor/metal-complex hybrid photocatalysts

    SciTech Connect (OSTI)

    Morikawa, T., E-mail: morikawa@mosk.tytlabs.co.jp; Sato, S., E-mail: morikawa@mosk.tytlabs.co.jp; Arai, T., E-mail: morikawa@mosk.tytlabs.co.jp; Uemura, K., E-mail: morikawa@mosk.tytlabs.co.jp; Yamanaka, K. I., E-mail: morikawa@mosk.tytlabs.co.jp; Suzuki, T. M., E-mail: morikawa@mosk.tytlabs.co.jp; Kajino, T., E-mail: morikawa@mosk.tytlabs.co.jp; Motohiro, T., E-mail: morikawa@mosk.tytlabs.co.jp [Toyota Central R and D Labs, Inc., Nagakute, Aichi 480-1192 (Japan)

    2013-12-10T23:59:59.000Z

    We developed a new hybrid photocatalyst for CO{sub 2} reduction, which is composed of a semiconductor and a metal complex. In the hybrid photocatalyst, ?G between the position of conduction band minimum (E{sub CBM}) of the semiconductor and the CO{sub 2} reduction potential of the complex is an essential factor for realizing fast electron transfer from the conduction band of semiconductor to metal complex leading to high photocatalytic activity. On the basis of this concept, the hybrid photocatalyst InP/Ru-complex, which functions in aqueous media, was developed. The photoreduction of CO{sub 2} to formate using water as an electron donor and a proton source was successfully achieved as a Z-scheme system by functionally conjugating the InP/Ru-complex photocatalyst for CO{sub 2} reduction with a TiO{sub 2} photocatalyst for water oxidation. The conversion efficiency from solar energy to chemical energy was ca. 0.04%, which approaches that for photosynthesis in a plant. Because this system can be applied to many other inorganic semiconductors and metal-complex catalysts, the efficiency and reaction selectivity can be enhanced by optimization of the electron transfer process including the energy-band configurations, conjugation conformations, and catalyst structures. This electrical-bias-free reaction is a huge leap forward for future practical applications of artificial photosynthesis under solar irradiation to produce organic species.

  18. 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.

  19. IEEE TRANSACTIONS ON NANOTECHNOLOGY, VOL. 10, NO. 3, MAY 2011 499 TiSi2 Nanocrystal Metal Oxide Semiconductor Field

    E-Print Network [OSTI]

    Yang, Zheng

    IEEE TRANSACTIONS ON NANOTECHNOLOGY, VOL. 10, NO. 3, MAY 2011 499 TiSi2 Nanocrystal Metal Oxide memory window, faster writing and erasing, and longer retention lifetime as a result of the metallic property of the silicide NCs. Due to thermally stable, CMOS compatible properties, TiSi2 NCs are highly

  20. Silicon metal-semiconductor-metal photodetector

    DOE Patents [OSTI]

    Brueck, Steven R. J. (Albuquerque, NM); Myers, David R. (Albuquerque, NM); Sharma, Ashwani K. (Albuquerque, NM)

    1997-01-01T23:59:59.000Z

    Silicon MSM photodiodes sensitive to radiation in the visible to near infrared spectral range are produced by altering the absorption characteristics of crystalline Si by ion implantation. The implantation produces a defected region below the surface of the silicon with the highest concentration of defects at its base which acts to reduce the contribution of charge carriers formed below the defected layer. The charge carriers generated by the radiation in the upper regions of the defected layer are very quickly collected between biased Schottky barrier electrodes which form a metal-semiconductor-metal structure for the photodiode.

  1. Silicon metal-semiconductor-metal photodetector

    DOE Patents [OSTI]

    Brueck, Steven R. J. (Albuquerque, NM); Myers, David R. (Albuquerque, NM); Sharma, Ashwani K. (Albuquerque, NM)

    1995-01-01T23:59:59.000Z

    Silicon MSM photodiodes sensitive to radiation in the visible to near infrared spectral range are produced by altering the absorption characteristics of crystalline Si by ion implantation. The implantation produces a defected region below the surface of the silicon with the highest concentration of defects at its base which acts to reduce the contribution of charge carriers formed below the defected layer. The charge carriers generated by the radiation in the upper regions of the defected layer are very quickly collected between biased Schottky barrier electrodes which form a metal-semiconductor-metal structure for the photodiode.

  2. Electrical characteristics and thermal stability of HfO{sub 2} metal-oxide-semiconductor capacitors fabricated on clean reconstructed GaSb surfaces

    SciTech Connect (OSTI)

    Miyata, Noriyuki, E-mail: nori.miyata@aist.go.jp; Mori, Takahiro; Yasuda, Tetsuji [National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Ohtake, Akihiro [National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044 (Japan); Ichikawa, Masakazu [The University of Tokyo, Tokyo 113-8656 (Japan)

    2014-06-09T23:59:59.000Z

    HfO{sub 2}/GaSb interfaces fabricated by high-vacuum HfO{sub 2} deposition on clean reconstructed GaSb surfaces were examined to explore a thermally stable GaSb metal-oxide-semiconductor structure with low interface-state density (D{sub it}). Interface Sb-O bonds were electrically and thermally unstable, and post-metallization annealing at temperatures higher than 200?°C was required to stabilize the HfO{sub 2}/GaSb interfaces. However, the annealing led to large D{sub it} in the upper-half band gap. We propose that the decomposition products that are associated with elemental Sb atoms act as interface states, since a clear correlation between the D{sub it} and the Sb coverage on the initial GaSb surfaces was observed.

  3. Hydrogenated Graphene Nanoflakes: Semiconductor to Half-Metal...

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

    Hydrogenated Graphene Nanoflakes: Semiconductor to Half-Metal Transition and Remarkable Large Magnetism. Hydrogenated Graphene Nanoflakes: Semiconductor to Half-Metal Transition...

  4. 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.

  5. Thin film three-dimensional topological insulator metal-oxide-semiconductor field-effect-transistors: A candidate for sub-10?nm devices

    SciTech Connect (OSTI)

    Akhavan, N. D., E-mail: nima.dehdashti@uwa.edu.au; Jolley, G.; Umana-Membreno, G. A.; Antoszewski, J.; Faraone, L. [Department of Electrical, Electronic and Computer Engineering, University of Western Australia, Crawley, WA 6009 (Australia)

    2014-08-28T23:59:59.000Z

    Three-dimensional (3D) topological insulators (TI) are a new state of quantum matter in which surface states reside in the bulk insulating energy bandgap and are protected by time-reversal symmetry. It is possible to create an energy bandgap as a consequence of the interaction between the conduction band and valence band surface states from the opposite surfaces of a TI thin film, and the width of the bandgap can be controlled by the thin film thickness. The formation of an energy bandgap raises the possibility of thin-film TI-based metal-oxide-semiconductor field-effect-transistors (MOSFETs). In this paper, we explore the performance of MOSFETs based on thin film 3D-TI structures by employing quantum ballistic transport simulations using the effective continuous Hamiltonian with fitting parameters extracted from ab-initio calculations. We demonstrate that thin film transistors based on a 3D-TI structure provide similar electrical characteristics compared to a Si-MOSFET for gate lengths down to 10?nm. Thus, such a device can be a potential candidate to replace Si-based MOSFETs in the sub-10?nm regime.

  6. Characterization of device parameters in high-temperature metal-oxide-semiconductor field-effect transistors in. beta. -SiC thin films

    SciTech Connect (OSTI)

    Palmour, J.W.; Kong, H.S.; Davis, R.F.

    1988-08-15T23:59:59.000Z

    Both inversion- and depletion-mode n-channel metal-oxide-semiconductor field-effect transistors (MOSFETs) have been fabricated on ..beta..-SiC thin films grown by chemical-vapor deposition. The inversion-mode devices were made on in situ doped (Al) p-type ..beta..-SiC(100) thin films grown on Si(100) substrates. The depletion-mode MOSFETs were made on n-type ..beta..-SiC(111) thin films grown on the Si(0001) face of a 6H ..cap alpha..-SiC substrates. Stable saturation and low subthreshold currents were achieved at drain-source voltages exceeding 5 and 25 V for the inversion-mode and depletion-mode devices, respectively. The transconductance increased with temperature up to 673 K for the short-gate-length devices, of either mode, and then decreased with further increases in temperature. It is proposed that the transconductances and threshold voltages for the inversion-mode devices are greatly affected by minority-carrier injection from the source. Stable transistor action was observed for both types of devices at temperatures up to 823 K, with the depletion-mode devices operating very well up to 923 K.

  7. Positive bias temperature instability in p-type metal-oxide-semiconductor devices with HfSiON/SiO{sub 2} gate dielectrics

    SciTech Connect (OSTI)

    Samanta, Piyas, E-mail: piyas@vcfw.org [Department of Physics, Vidyasagar College for Women, 39 Sankar Ghosh Lane, Kolkata 700 006 (India); Huang, Heng-Sheng; Chen, Shuang-Yuan [Institute of Mechatronic Engineering, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd., Taipei 106, Taiwan (China); Liu, Chuan-Hsi [Department of Mechatronic Technology, National Taiwan Normal University, No. 162, Sec. 1, He-Ping E. Rd., Taipei 106, Taiwan (China); Cheng, Li-Wei [Central R and D Division, United Microelectronics Corporation, No. 3, Li-Hsin Rd. II, Hsinchu 300, Taiwan (China)

    2014-02-21T23:59:59.000Z

    We present a detailed investigation on positive-bias temperature stress (PBTS) induced degradation of nitrided hafnium silicate (HfSiON)/SiO{sub 2} gate stack in n{sup +}-poly crystalline silicon (polySi) gate p-type metal-oxide-semiconductor (pMOS) devices. The measurement results indicate that gate dielectric degradation is a composite effect of electron trapping in as-fabricated as well as newly generated neutral traps, resulting a significant amount of stress-induced leakage current and generation of surface states at the Si/SiO{sub 2} interface. Although, a significant amount of interface states are created during PBTS, the threshold voltage (V{sub T}) instability of the HfSiON based pMOS devices is primarily caused by electron trapping and detrapping. It is also shown that PBTS creates both acceptor- and donor-like interface traps via different depassivation mechanisms of the Si{sub 3}???SiH bonds at the Si/SiO{sub 2} interface in pMOS devices. However, the number of donor-like interface traps ?N{sub it}{sup D} is significantly greater than that of acceptor-like interface traps ?N{sup A}{sub it}, resulting the PBTS induced net interface traps as donor-like.

  8. Sample size requirements for estimating effective dose from computed tomography using solid-state metal-oxide-semiconductor field-effect transistor dosimetry

    SciTech Connect (OSTI)

    Trattner, Sigal [Department of Medicine, Division of Cardiology, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York 10032 (United States)] [Department of Medicine, Division of Cardiology, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York 10032 (United States); Cheng, Bin [Department of Biostatistics, Columbia University Mailman School of Public Health, New York, New York 10032 (United States)] [Department of Biostatistics, Columbia University Mailman School of Public Health, New York, New York 10032 (United States); Pieniazek, Radoslaw L. [Center for Radiological Research, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York 10032 (United States)] [Center for Radiological Research, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York 10032 (United States); Hoffmann, Udo [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 (United States)] [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 (United States); Douglas, Pamela S. [Department of Medicine, Division of Cardiology, Duke University, Durham, North Carolina 27715 (United States)] [Department of Medicine, Division of Cardiology, Duke University, Durham, North Carolina 27715 (United States); Einstein, Andrew J., E-mail: andrew.einstein@columbia.edu [Department of Medicine, Division of Cardiology, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York and Department of Radiology, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York (United States)

    2014-04-15T23:59:59.000Z

    Purpose: Effective dose (ED) is a widely used metric for comparing ionizing radiation burden between different imaging modalities, scanners, and scan protocols. In computed tomography (CT), ED can be estimated by performing scans on an anthropomorphic phantom in which metal-oxide-semiconductor field-effect transistor (MOSFET) solid-state dosimeters have been placed to enable organ dose measurements. Here a statistical framework is established to determine the sample size (number of scans) needed for estimating ED to a desired precision and confidence, for a particular scanner and scan protocol, subject to practical limitations. Methods: The statistical scheme involves solving equations which minimize the sample size required for estimating ED to desired precision and confidence. It is subject to a constrained variation of the estimated ED and solved using the Lagrange multiplier method. The scheme incorporates measurement variation introduced both by MOSFET calibration, and by variation in MOSFET readings between repeated CT scans. Sample size requirements are illustrated on cardiac, chest, and abdomen–pelvis CT scans performed on a 320-row scanner and chest CT performed on a 16-row scanner. Results: Sample sizes for estimating ED vary considerably between scanners and protocols. Sample size increases as the required precision or confidence is higher and also as the anticipated ED is lower. For example, for a helical chest protocol, for 95% confidence and 5% precision for the ED, 30 measurements are required on the 320-row scanner and 11 on the 16-row scanner when the anticipated ED is 4 mSv; these sample sizes are 5 and 2, respectively, when the anticipated ED is 10 mSv. Conclusions: Applying the suggested scheme, it was found that even at modest sample sizes, it is feasible to estimate ED with high precision and a high degree of confidence. As CT technology develops enabling ED to be lowered, more MOSFET measurements are needed to estimate ED with the same precision and confidence.

  9. A methodology to identify and quantify mobility-reducing defects in 4H-silicon carbide power metal-oxide-semiconductor field-effect transistors

    SciTech Connect (OSTI)

    Ettisserry, D. P., E-mail: deva@umd.edu; Goldsman, N. [Department of Electrical and Computer Engineering, University of Maryland, College Park, Maryland 20742 (United States); Lelis, A. [U.S. Army Research Laboratory, 2800 Powder Mill Road, Adelphi, Maryland 20783 (United States)

    2014-03-14T23:59:59.000Z

    In this paper, we present a methodology for the identification and quantification of defects responsible for low channel mobility in 4H-Silicon Carbide (SiC) power metal-oxide-semiconductor field-effect transistors (MOSFETs). To achieve this, we use an algorithm based on 2D-device simulations of a power MOSFET, density functional simulations, and measurement data. Using physical modeling of carrier mobility and interface traps, we reproduce the experimental I-V characteristics of a 4H-SiC doubly implanted MOSFET through drift-diffusion simulation. We extract the position of Fermi level and the occupied trap density as a function of applied bias and temperature. Using these inputs, our algorithm estimates the number of possible trap types, their energy levels, and concentrations at 4H-SiC/SiO{sub 2} interface. Subsequently, we use density functional theory (DFT)-based ab initio simulations to identify the atomic make-up of defects causing these trap levels. We study silicon vacancy and carbon di-interstitial defects in the SiC side of the interface. Our algorithm indicates that the D{sub it} spectrum near the conduction band edge (3.25?eV) is composed of three trap types located at 2.8–2.85?eV, 3.05?eV, and 3.1–3.2?eV, and also calculates their densities. Based on DFT simulations, this work attributes the trap levels very close to the conduction band edge to the C di-interstitial defect.

  10. L{sub g}?=?100?nm In{sub 0.7}Ga{sub 0.3}As quantum well metal-oxide semiconductor field-effect transistors with atomic layer deposited beryllium oxide as interfacial layer

    SciTech Connect (OSTI)

    Koh, D., E-mail: dh.koh@utexas.edu, E-mail: Taewoo.Kim@sematech.org [Department of Electrical and Computer Engineering, Microelectronics Research Center, The University of Texas at Austin, Austin, Texas 78758 (United States); SEMATECH, Inc., Albany, New York 12203 (United States); Kwon, H. M. [Department of Electronics Engineering, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Kim, T.-W., E-mail: dh.koh@utexas.edu, E-mail: Taewoo.Kim@sematech.org; Veksler, D.; Gilmer, D.; Kirsch, P. D. [SEMATECH, Inc., Albany, New York 12203 (United States); Kim, D.-H. [SEMATECH, Inc., Albany, New York 12203 (United States); GLOBALFOUNDRIES, Malta, New York 12020 (United States); Hudnall, Todd W. [Department of Chemistry and Biochemistry, Texas State University, San Marcos, Texas, 78666 (United States); Bielawski, Christopher W. [Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712 (United States); Maszara, W. [GLOBALFOUNDRIES, Santa Clara, California 95054 (United States); Banerjee, S. K. [Department of Electrical and Computer Engineering, Microelectronics Research Center, The University of Texas at Austin, Austin, Texas 78758 (United States)

    2014-04-21T23:59:59.000Z

    In this study, we have fabricated nanometer-scale channel length quantum-well (QW) metal-oxide-semiconductor field effect transistors (MOSFETs) incorporating beryllium oxide (BeO) as an interfacial layer. BeO has high thermal stability, excellent electrical insulating characteristics, and a large band-gap, which make it an attractive candidate for use as a gate dielectric in making MOSFETs. BeO can also act as a good diffusion barrier to oxygen owing to its small atomic bonding length. In this work, we have fabricated In{sub 0.53}Ga{sub 0.47}As MOS capacitors with BeO and Al{sub 2}O{sub 3} and compared their electrical characteristics. As interface passivation layer, BeO/HfO{sub 2} bilayer gate stack presented effective oxide thickness less 1 nm. Furthermore, we have demonstrated In{sub 0.7}Ga{sub 0.3}As QW MOSFETs with a BeO/HfO{sub 2} dielectric, showing a sub-threshold slope of 100?mV/dec, and a transconductance (g{sub m,max}) of 1.1 mS/?m, while displaying low values of gate leakage current. These results highlight the potential of atomic layer deposited BeO for use as a gate dielectric or interface passivation layer for III–V MOSFETs at the 7?nm technology node and/or beyond.

  11. A Sensor System Based on Semi-Conductor Metal Oxide Technology for In Situ Detection of Coal Fired Combustion Gases

    SciTech Connect (OSTI)

    Brent Marquis

    2007-05-31T23:59:59.000Z

    Sensor Research and Development Corporation (SRD) proposed a two-phase program to develop a robust, autonomous prototype analyzer for in situ, real-time detection, identification, and measurement of coal-fired combustion gases and perform field-testing at an approved power generation facility. SRD developed and selected sensor materials showing selective responses to carbon monoxide, carbon dioxide, nitric oxide, nitrogen dioxide, ammonia, sulfur dioxide and hydrogen chloride. Sensor support electronics were also developed to enable prototype to function in elevated temperatures without any issues. Field-testing at DOE approved facility showed the ability of the prototype to detect and estimate the concentration of combustion by-products accurately with relatively low false-alarm rates at very fast sampling intervals.

  12. Impact of SF{sub 6} plasma treatment on performance of TaN-HfO{sub 2}-InP metal-oxide-semiconductor field-effect transistor

    SciTech Connect (OSTI)

    Wang Yanzhen; Chen Yenting; Zhao Han; Xue Fei; Zhou Fei; Lee, Jack C. [Department of Electrical and Computer Engineering, Microelectronics Research Center, University of Texas at Austin, Austin, Texas 78758 (United States)

    2011-01-24T23:59:59.000Z

    In this work, the experimental impact of SF{sub 6} plasma treatment on the performance of InP metal-oxide-semiconductor field-effect transistors is presented. S and F are incorporated into atomic layer deposited HfO{sub 2} via postgate SF{sub 6} plasma treatment. The decreased subthreshold swing, gate leakage (I{sub g}), and increased effective channel mobility ({mu}{sub eff}) indicate that better interface and bulk oxide quality have been achieved with SF{sub 6} plasma treatment due to the formation of stronger Hf-F bonds. Drive current (I{sub d}), transconductance (G{sub m}), and effective channel mobility ({mu}{sub eff}) are improved by 22.3%, 35%, and 35%, respectively, compared with those of control devices.

  13. Lattice matched semiconductor growth on crystalline metallic substrates

    DOE Patents [OSTI]

    Norman, Andrew G; Ptak, Aaron J; McMahon, William E

    2013-11-05T23:59:59.000Z

    Methods of fabricating a semiconductor layer or device and said devices are disclosed. The methods include but are not limited to providing a metal or metal alloy substrate having a crystalline surface with a known lattice parameter (a). The methods further include growing a crystalline semiconductor alloy layer on the crystalline substrate surface by coincident site lattice matched epitaxy. The semiconductor layer may be grown without any buffer layer between the alloy and the crystalline surface of the substrate. The semiconductor alloy may be prepared to have a lattice parameter (a') that is related to the lattice parameter (a). The semiconductor alloy may further be prepared to have a selected band gap.

  14. Project Profile: High Performance Reduction/Oxidation Metal Oxides...

    Office of Environmental Management (EM)

    High Performance ReductionOxidation Metal Oxides for Thermochemical Energy Storage Project Profile: High Performance ReductionOxidation Metal Oxides for Thermochemical Energy...

  15. 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.

  16. 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.

  17. Microbially-mediated method for synthesis of non-oxide semiconductor nanoparticles

    DOE Patents [OSTI]

    Phelps, Tommy J.; Lauf, Robert J.; Moon, Ji Won; Rondinone, Adam J.; Love, Lonnie J.; Duty, Chad Edward; Madden, Andrew Stephen; Li, Yiliang; Ivanov, Ilia N.; Rawn, Claudia Jeanette

    2014-06-24T23:59:59.000Z

    The invention is directed to a method for producing non-oxide semiconductor nanoparticles, the method comprising: (a) subjecting a combination of reaction components to conditions conducive to microbially-mediated formation of non-oxide semiconductor nanoparticles, wherein said combination of reaction components comprises i) anaerobic microbes, ii) a culture medium suitable for sustaining said anaerobic microbes, iii) a metal component comprising at least one type of metal ion, iv) a non-metal component containing at least one non-metal selected from the group consisting of S, Se, Te, and As, and v) one or more electron donors that provide donatable electrons to said anaerobic microbes during consumption of the electron donor by said anaerobic microbes; and (b) isolating said non-oxide semiconductor nanoparticles, which contain at least one of said metal ions and at least one of said non-metals. The invention is also directed to non-oxide semiconductor nanoparticle compositions produced as above and having distinctive properties.

  18. Metal-semiconductor hybrid thin films in field-effect transistors

    SciTech Connect (OSTI)

    Okamura, Koshi, E-mail: koshi.okamura@kit.edu; Dehm, Simone [Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), 76021 Karlsruhe (Germany)] [Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), 76021 Karlsruhe (Germany); Hahn, Horst [Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), 76021 Karlsruhe (Germany) [Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), 76021 Karlsruhe (Germany); KIT-TUD Joint Research Laboratory Nanomaterials, Technische Universität Darmstadt, Petersenstr. 32, 64287 Darmstadt (Germany)

    2013-12-16T23:59:59.000Z

    Metal-semiconductor hybrid thin films consisting of an amorphous oxide semiconductor and a number of aluminum dots in different diameters and arrangements are formed by electron beam lithography and employed for thin-film transistors (TFTs). Experimental and computational demonstrations systematically reveal that the field-effect mobility of the TFTs enhances but levels off as the dot density increases, which originates from variations of the effective channel length that strongly depends on the electric field distribution in a transistor channel.

  19. 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 ...

  20. Monolithic integration of rare-earth oxides and semiconductors for on-silicon technology

    SciTech Connect (OSTI)

    Dargis, Rytis, E-mail: dargis@translucentinc.com; Clark, Andrew; Erdem Arkun, Fevzi [Translucent, Inc., 952 Commercial St., Palo Alto, California 94303 (United States); Grinys, Tomas; Tomasiunas, Rolandas [Institute of Applied Research, Vilnius University, Sauletekio al. 10, LT-10223 Vilnius (Lithuania); O'Hara, Andy; Demkov, Alexander A. [Department of Physics, The University of Texas at Austin, 2515 Speedway, C1600, Austin, Texas 78712 (United States)

    2014-07-01T23:59:59.000Z

    Several concepts of integration of the epitaxial rare-earth oxides into the emerging advanced semiconductor on silicon technology are presented. Germanium grows epitaxially on gadolinium oxide despite lattice mismatch of more than 4%. Additionally, polymorphism of some of the rare-earth oxides allows engineering of their crystal structure from hexagonal to cubic and formation of buffer layers that can be used for growth of germanium on a lattice matched oxide layer. Molecular beam epitaxy and metal organic chemical vapor deposition of gallium nitride on the rare-earth oxide buffer layers on silicon is discussed.

  1. Ferromagnetism in Doped Thin-Film Oxide and Nitride Semiconductors and Dielectrics

    SciTech Connect (OSTI)

    Chambers, Scott A.

    2006-10-01T23:59:59.000Z

    The principal goal in the field of high-Tc ferromagnetic semiconductors is the synthesis, characterization and utilization of semiconductors which exhibit substantial carrier spin polarization at and above room temperature. Such materials are of critical importance in the emerging field of semiconductor spintronics. The interaction leading to carrier spin polarization, exchange coupling between the dopant spins and the valence or conduction band, is known to be sufficiently weak in conventional semiconductors, such as GaAs and Si, that magnetic ordering above cryogenic temperatures is essentially impossible. Since the provocative theoretical predictions of Tc above ambient in p-Mn:ZnO and p-Mn:GaN (T. Dietl et al., Science 287 1019 (2000)), and the observation of room-temperature ferromagnetism in Co:TiO2 anatase (Y. Matsumoto et al., Science 291 854 (2001)), there has been a flurry of work in oxides and nitrides doped with transition metals with unpaired d electrons. It has even been claimed that room-temperature ferromagnetism can be obtained in certain d0 transition metals oxides without a dopant. In this Report, the field of transition metal doped oxides and nitrides is critically reviewed and assessed from a materials science perspective. Since much of the field centers around thin film growth, this Report focuses on films prepared not only by conventional vacuum deposition methods, but also by spin coating colloidal nanoparticles.

  2. Multiple percolation tunneling staircase in metal-semiconductor nanoparticle composites

    SciTech Connect (OSTI)

    Mukherjee, Rupam; Huang, Zhi-Feng; Nadgorny, Boris [Department of Physics and Astronomy, Wayne State University, Detroit, Michigan 48201 (United States)

    2014-10-27T23:59:59.000Z

    Multiple percolation transitions are observed in a binary system of RuO{sub 2}-CaCu{sub 3}Ti{sub 4}O{sub 12} metal-semiconductor nanoparticle composites near percolation thresholds. Apart from a classical percolation transition, associated with the appearance of a continuous conductance path through RuO{sub 2} metal oxide nanoparticles, at least two additional tunneling percolation transitions are detected in this composite system. Such behavior is consistent with the recently emerged picture of a quantum conductivity staircase, which predicts several percolation tunneling thresholds in a system with a hierarchy of local tunneling conductance, due to various degrees of proximity of adjacent conducting particles distributed in an insulating matrix. Here, we investigate a different type of percolation tunneling staircase, associated with a more complex conductive and insulating particle microstructure of two types of non-spherical constituents. As tunneling is strongly temperature dependent, we use variable temperature measurements to emphasize the hierarchical nature of consecutive tunneling transitions. The critical exponents corresponding to specific tunneling percolation thresholds are found to be nonuniversal and temperature dependent.

  3. Low temperature lithographically patterned metal oxide transistors for large area electronics

    E-Print Network [OSTI]

    Wang, Annie I. (Annie I-Jen), 1981-

    2011-01-01T23:59:59.000Z

    Optically transparent, wide bandgap metal oxide semiconductors are a promising candidate for large-area electronics technologies that require lightweight, temperature-sensitive flexible substrates. Because these thin films ...

  4. Nanostructured Metal Oxide Anodes (Presentation)

    SciTech Connect (OSTI)

    Dillon, A. C.; Riley, L. A.; Lee, S.-H.; Kim, Y.-H.; Ban, C.; Gillaspie, D. T.; Pesaran, A.

    2009-05-01T23:59:59.000Z

    This summarizes NREL's FY09 battery materials research activity in developing metal oxide nanostructured anodes to enable high-energy, durable and affordable li-ion batteries for HEVs and PHEVs.

  5. amorphous oxide semiconductor: Topics by E-print Network

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

    Summary: alloy of composition correspond- ing to the metallic components of the superconduct- ing oxides respectivement. Abstract. - Previous quenching experiments on 2212...

  6. 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.

  7. Low interface defect density of atomic layer deposition BeO with self-cleaning reaction for InGaAs metal oxide semiconductor field effect transistors

    SciTech Connect (OSTI)

    Shin, H. S. [Department of Electronics Engineering, Chungnam National University, Daejeon (Korea, Republic of) [Department of Electronics Engineering, Chungnam National University, Daejeon (Korea, Republic of); SEMATECH, 2706 Montopolis Dr., Austin, Texas 78741 (United States); The University of Texas, Austin, Texas 78758 (United States); Yum, J. H. [SEMATECH, 2706 Montopolis Dr., Austin, Texas 78741 (United States) [SEMATECH, 2706 Montopolis Dr., Austin, Texas 78741 (United States); The University of Texas, Austin, Texas 78758 (United States); Johnson, D. W. [SEMATECH, 2706 Montopolis Dr., Austin, Texas 78741 (United States) [SEMATECH, 2706 Montopolis Dr., Austin, Texas 78741 (United States); Texas A and M University College Station, Texas 77843 (United States); Harris, H. R. [Texas A and M University College Station, Texas 77843 (United States)] [Texas A and M University College Station, Texas 77843 (United States); Hudnall, Todd W. [Texas State University, 601 University Drive, San Marcos, Texas 78666 (United States)] [Texas State University, 601 University Drive, San Marcos, Texas 78666 (United States); Oh, J. [Yonsei University, Incheon, 406-840 (Korea, Republic of)] [Yonsei University, Incheon, 406-840 (Korea, Republic of); Kirsch, P.; Wang, W.-E. [SEMATECH, 2706 Montopolis Dr., Austin, Texas 78741 (United States)] [SEMATECH, 2706 Montopolis Dr., Austin, Texas 78741 (United States); Bielawski, C. W.; Banerjee, S. K.; Lee, J. C. [The University of Texas, Austin, Texas 78758 (United States)] [The University of Texas, Austin, Texas 78758 (United States); Lee, H. D. [Department of Electronics Engineering, Chungnam National University, Daejeon (Korea, Republic of)] [Department of Electronics Engineering, Chungnam National University, Daejeon (Korea, Republic of)

    2013-11-25T23:59:59.000Z

    In this paper, we discuss atomic configuration of atomic layer deposition (ALD) beryllium oxide (BeO) using the quantum chemistry to understand the theoretical origin. BeO has shorter bond length, higher reaction enthalpy, and larger bandgap energy compared with those of ALD aluminum oxide. It is shown that the excellent material properties of ALD BeO can reduce interface defect density due to the self-cleaning reaction and this contributes to the improvement of device performance of InGaAs MOSFETs. The low interface defect density and low leakage current of InGaAs MOSFET were demonstrated using X-ray photoelectron spectroscopy and the corresponding electrical results.

  8. 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.

  9. 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.

  10. Investigation of abnormal negative threshold voltage shift under positive bias stress in input/output n-channel metal-oxide-semiconductor field-effect transistors with TiN/HfO{sub 2} structure using fast I-V measurement

    SciTech Connect (OSTI)

    Ho, Szu-Han; Chen, Ching-En; Tseng, Tseung-Yuen [Department of Electronics Engineering, National Chiao Tung University, Hsinchu 300, Taiwan (China); Chang, Ting-Chang, E-mail: tcchang@mail.phys.nsysu.edu.tw; Lu, Ying-Hsin; Tsai, Jyun-Yu; Liu, Kuan-Ju [Department of Physics, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); Cheng, Osbert; Huang, Cheng-Tung; Lu, Ching-Sen [Device Department, United Microelectronics Corporation, Tainan Science Park, Taiwan (China)

    2014-03-17T23:59:59.000Z

    This letter investigates abnormal negative threshold voltage shifts under positive bias stress in input/output (I/O) TiN/HfO{sub 2} n-channel metal-oxide-semiconductor field-effect transistors using fast I-V measurement. This phenomenon is attributed to a reversible charge/discharge effect in pre-existing bulk traps. Moreover, in standard performance devices, threshold-voltage (V{sub t}) shifts positively during fast I-V double sweep measurement. However, in I/O devices, V{sub t} shifts negatively since electrons escape from bulk traps to metal gate rather than channel electrons injecting to bulk traps. Consequently, decreasing pre-existing bulk traps in I/O devices, which can be achieved by adopting Hf{sub x}Zr{sub 1?x}O{sub 2} as gate oxide, can reduce the charge/discharge effect.

  11. Generic process for preparing a crystalline oxide upon a group IV semiconductor substrate

    DOE Patents [OSTI]

    McKee, Rodney A. (Kingston, TN); Walker, Frederick J. (Oak Ridge, TN); Chisholm, Matthew F. (Oak Ridge, TN)

    2000-01-01T23:59:59.000Z

    A process for growing a crystalline oxide epitaxially upon the surface of a Group IV semiconductor, as well as a structure constructed by the process, is described. The semiconductor can be germanium or silicon, and the crystalline oxide can generally be represented by the formula (AO).sub.n (A'BO.sub.3).sub.m in which "n" and "m" are non-negative integer repeats of planes of the alkaline earth oxides or the alkaline earth-containing perovskite oxides. With atomic level control of interfacial thermodynamics in a multicomponent semiconductor/oxide system, a highly perfect interface between a semiconductor and a crystalline oxide can be obtained.

  12. Metal Oxide Semiconductors for Solar Energy Harvesting.

    E-Print Network [OSTI]

    Thimsen, Elijah

    2009-01-01T23:59:59.000Z

    ??The correlation between energy consumption and human development illustrates the importance of this societal resource. We will consume more energy in the future. In light… (more)

  13. 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...

  14. A 75 GHz silicon metal-semiconductor-metal Schottky photodiode Sotiris Alexandrou, Chia-Chi Wang, and Thomas Y. Hsiang

    E-Print Network [OSTI]

    A 75 GHz silicon metal-semiconductor-metal Schottky photodiode Sotiris Alexandrou, Chia-Chi Wang-semiconductor-metal (MSM) photodiodes with 300 nm finger width and spacing were measured with a subpicosecond electro of silicon MSM photodiodes. A configuration is suggested to improve the speed of these detectors at long

  15. Wide-band-gap, alkaline-earth-oxide semiconductor and devices utilizing same

    DOE Patents [OSTI]

    Abraham, Marvin M. (Oak Ridge, TN); Chen, Yok (Oak Ridge, TN); Kernohan, Robert H. (Oak Ridge, TN)

    1981-01-01T23:59:59.000Z

    This invention relates to novel and comparatively inexpensive semiconductor devices utilizing semiconducting alkaline-earth-oxide crystals doped with alkali metal. The semiconducting crystals are produced by a simple and relatively inexpensive process. As a specific example, a high-purity lithium-doped MgO crystal is grown by conventional techniques. The crystal then is heated in an oxygen-containing atmosphere to form many [Li].degree. defects therein, and the resulting defect-rich hot crystal is promptly quenched to render the defects stable at room temperature and temperatures well above the same. Quenching can be effected conveniently by contacting the hot crystal with room-temperature air.

  16. 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...

  17. 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.

  18. 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.

  19. Polarization dependence of the temporal response of metal-semiconductor-metal photodetectors

    E-Print Network [OSTI]

    Van Driel, Henry M.

    of MSM-PD effi- ciency when the electrode period ( ) is comparable to the wavelength of the incident-semiconductor-metal photodetector temporal response is shown to be significant, and largest for devices with electrode periods less insensitive devices require special electrode patterning7 or . When used as a polarization analyzer/ detector

  20. 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

    I• I ntroduct Ion Metal oxide varistors are ceramic semi-SECTION M METAL' OXIDE PHASE IN A ZINC OXIDE VARISTORTHE INTERGRANULAR METAL OXIDE PHASE IN A ZINC OXIDE VARISTOR

  1. 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.

  2. Ultrathin metal-semiconductor-metal resonator for angle invariant visible band transmission filters

    SciTech Connect (OSTI)

    Lee, Kyu-Tae; Seo, Sungyong; Yong Lee, Jae; Jay Guo, L., E-mail: guo@umich.edu [Department of Electrical Engineering and Computer Science, The University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2014-06-09T23:59:59.000Z

    We present transmission visible wavelength filters based on strong interference behaviors in an ultrathin semiconductor material between two metal layers. The proposed devices were fabricated on 2?cm?×?2?cm glass substrate, and the transmission characteristics show good agreement with the design. Due to a significantly reduced light propagation phase change associated with the ultrathin semiconductor layer and the compensation in phase shift of light reflecting from the metal surface, the filters show an angle insensitive performance up to ±70°, thus, addressing one of the key challenges facing the previously reported photonic and plasmonic color filters. This principle, described in this paper, can have potential for diverse applications ranging from color display devices to the image sensors.

  3. 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.

  4. 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.

  5. Method for making monolithic metal oxide aerogels

    SciTech Connect (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.

  6. 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.

  7. 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.

  8. 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.

  9. 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...

  10. Understanding Atom Probe Tomography of Oxide-Supported Metal...

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

    Atom Probe Tomography of Oxide-Supported Metal Nanoparticles by Correlation with Atomic Resolution Electron Understanding Atom Probe Tomography of Oxide-Supported Metal...

  11. Oxide Ferromagnetic Semiconductors for Spin-Electronic Transprt

    SciTech Connect (OSTI)

    Dr. R. K. Pandey, Cudworth Endowed Professor (Professor Emeritus of The Unviersity of Alabama)

    2008-11-24T23:59:59.000Z

    The objective of this research was to investigate the viability of oxide magnetic semiconductors as potential materials for spintronics. We identified some members of the solid solution series of ilmenite (FeTiO3) and hematite (Fe2O3), abbreviated as (IH) for simplicity, for our investigations based on their ferromagnetic and semiconducting properties. With this objective in focus we limited our investigations to the following members of the modified Fe-titanates: IH33 (ilmenitehematite with 33 atomic percent hematite), IH45 (ilmenite-hematite with 45 atomic percent hematite), Mn-substituted ilmenite (Mn-FeTiO3), and Mn-substituted pseudobrookite (Mn- Fe2TiO5). All of them are: 1. wide bandgap semiconductors with band gaps ranging in values between 2.5 to 3.5 eV; 2. n-type semiconductors; 3.they exhibit well defined magnetic hysteresis loops and 4. their magnetic Curie points are greater than 400K. Ceramic, film and single crystal samples were studied and based on their properties we produced varistors (also known as voltage dependent resistors) for microelectronic circuit protection from power surges, three-terminal microelectronic devices capable of generating bipolar currents, and an integrated structured device with controlled magnetic switching of spins. Eleven refereed journal papers, three refereed conference papers and three invention disclosures resulted from our investigations. We also presented invited papers in three international conferences and one national conference. Furthermore two students graduated with Ph.D. degrees, three with M.S. degrees and one with B.S. degree. Also two post-doctoral fellows were actively involved in this research. We established the radiation hardness of our devices in collaboration with a colleague in an HBCU institution, at the Cyclotron Center at Texas A&M University, and at DOE National Labs (Los Alamos and Brookhaven). It is to be appreciated that we met most of our goals and expanded vastly the scope of research by including investigations of Mn-FeTiO3, Mn-Fe2TiO5 and by producing a novel three terminal device capable of generating bipolar currents besides producing radiation resistant varistors and a magnetically switchable device. Furthermore we conclusively established the radiation hardness of the four modified iron titanates we studied. In all our publications, conference and seminar presentations, dissertations and theses sponsorship of DOE has been acknowledged

  12. Self-Assembled Metal/Molecule/Semiconductor Nanostructures for Electronic Device

    E-Print Network [OSTI]

    Woodall, Jerry M.

    565 Self-Assembled Metal/Molecule/Semiconductor Nanostructures for Electronic Device and Contact attracted interest for electronic device and ma- terials applications. The first class involves the for-assembled semiconductor structures, the electronic device functionality has been limited by the difficulty in achieving

  13. High temperature thermoelectric characterization of III-V semiconductor thin films by oxide bonding

    E-Print Network [OSTI]

    Bowers, John

    -W-N diffusion barrier. A thermoelectric material, thin film ErAs:InGaAlAs metal/semiconductor nanocomposite temperature to 840 K for this material and the results show the thermoelectric power factor multiplied material characterization of semiconductor thin films for thermoelectric power generation, photovoltaic

  14. High-Temperature Thermoelectric Characterization of IIIV Semiconductor Thin Films by Oxide Bonding

    E-Print Network [OSTI]

    -temperature thermoelectric charac- terization of thin-film III­V semiconductor materials that suffer from the side- effect-temperature surface passivation, and metallization with a Ti-W-N diffusion barrier. A thermoelectric material, thin-temperature material characterization of semiconductor thin films for thermoelectric power generation, photovoltaic

  15. Lattice mismatched compound semiconductors and devices on silicon

    E-Print Network [OSTI]

    Yang, Li, Ph. D. Massachusetts Institute of Technology

    2011-01-01T23:59:59.000Z

    III-V compound semiconductors, due to their superior electron mobility, are promising candidates for n-type metal-oxide-semiconductor field effect transistors (MOSFETs). However, the limited size of III-V substrates and ...

  16. Superatoms and Metal-Semiconductor Motifs for Cluster Materials

    SciTech Connect (OSTI)

    Castleman, A. W.

    2013-10-11T23:59:59.000Z

    A molecular understanding of catalysis and catalytically active materials is of fundamental importance in designing new substances for applications in energy and fuels. We have performed reactivity studies and ultrafast ionization and coulomb explosion studies on a variety of catalytically-relevant materials, including transition metal oxides of Fe, Co, Ni, Cu, Ti, V, Nb, and Ta. We demonstrate that differences in charge state, geometry, and elemental composition of clusters of such materials determine chemical reactivity and ionization behavior, crucial steps in improving performance of catalysts.

  17. Transition-metal silicides as materials for magnet-semiconductor heterostructures*

    E-Print Network [OSTI]

    Transition-metal silicides as materials for magnet-semiconductor heterostructures* Peter Kratzer as of binary late transition metal monosilicides, in contact with the Si surface. For the Heusler alloy Co2MnSi, we could show that the 001 surface retains the half-metallic character of the bulk if a fully Mn

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  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. 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.

  5. Metal-insulator-semiconductor structures on p-type GaAs with low interface state density

    E-Print Network [OSTI]

    Chen, Zhi

    Metal-insulator-semiconductor structures on p-type GaAs with low interface state density Zhi Chen properties of in situ deposited Si3N4 /Si/p-GaAs metal-insulator-semiconductor structures have been offered by a low gate leakage technology in GaAs, such as metal insulator structures, func- tional Ga

  6. 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 xLi2-yHyO.xM'O2.(1-x)Li1-zHzMO2 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 xLi2-yHy.xM'O2.(1-x)Li1-zHzMO2 material is prepared by preconditioning a precursor lithium metal oxide (i.e., xLi2M'O3.(1-x)LiMO2) 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.

  7. 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.

  8. Modeling of surface oxidation and oxidation induced damage in metal matrix composites

    E-Print Network [OSTI]

    Ma, Xinzheng

    1995-01-01T23:59:59.000Z

    Surface oxidation in metal matrix composites (MMC's) is modeled by Fickian diffusion of oxygen in both the oxide layer and metal matrix. The oxidation process and the resulting immobilized oxygen at the interface is accounted for by the introduction...

  9. 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.

  10. 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.

  11. Reactor process using metal oxide ceramic membranes

    DOE Patents [OSTI]

    Anderson, Marc A. (Madison, WI)

    1994-01-01T23:59:59.000Z

    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.

  12. 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.

  13. 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.

  14. Searching Room Temperature Ferromagnetism in Wide Gap Semiconductors Fe-doped Strontium Titanate and Zinc Oxide

    E-Print Network [OSTI]

    Pereira, LMC; Wahl, U

    Scientic findings in the very beginning of the millennium are taking us a step further in the new paradigm of technology: spintronics. Upgrading charge-based electronics with the additional degree of freedom of the carriers spin-state, spintronics opens a path to the birth of a new generation of devices with the potential advantages of non-volatility and higher processing speed, integration densities and power efficiency. A decisive step towards this new age lies on the attribution of magnetic properties to semiconductors, the building block of today's electronics, that is, the realization of ferromagnetic semiconductors (FS) with critical temperatures above room temperature. Unfruitful search for intrinsic RT FS lead to the concept of Dilute(d) Magnetic Semiconductors (DMS): ordinary semiconductor materials where 3 d transition metals randomly substitute a few percent of the matrix cations and, by some long-range mechanism, order ferromagnetically. The times are of intense research activity and the last few ...

  15. Low resistance barrier layer for isolating, adhering, and passivating copper metal in semiconductor fabrication

    SciTech Connect (OSTI)

    Weihs, Timothy P. (Baltimore, MD); Barbee, Jr., Troy W. (Palto Alto, CA)

    2002-01-01T23:59:59.000Z

    Cubic or metastable cubic refractory metal carbides act as barrier layers to isolate, adhere, and passivate copper in semiconductor fabrication. One or more barrier layers of the metal carbide are deposited in conjunction with copper metallizations to form a multilayer characterized by a cubic crystal structure with a strong (100) texture. Suitable barrier layer materials include refractory transition metal carbides such as vanadium carbide (VC), niobium carbide (NbC), tantalum carbide (TaC), chromium carbide (Cr.sub.3 C.sub.2), tungsten carbide (WC), and molybdenum carbide (MoC).

  16. Optical properties of metallic (III, Mn)V ferromagnetic semiconductors in the infrared to visible range

    E-Print Network [OSTI]

    Hankiewicz, EM; Jungwirth, T.; Dietl, T.; Timm, C.; Sinova, Jairo.

    2004-01-01T23:59:59.000Z

    We report on a study of the ac conductivity and magneto-optical properties of metallic ferromagnetic (III, Mn)V semiconductors in the infrared to visible spectrum at zero temperature. Our analysis is based on the successful kinetic exchange model...

  17. 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.

  18. 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.

  19. Versatile Applications of Nanostructured Metal Oxides

    E-Print Network [OSTI]

    Li, Li

    2014-05-29T23:59:59.000Z

    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... 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...

  20. High-performance self-aligned inversion-channel In{sub 0.53}Ga{sub 0.47}As metal-oxide-semiconductor field-effect-transistors by in-situ atomic-layer-deposited HfO{sub 2}

    SciTech Connect (OSTI)

    Lin, T. D.; Chang, W. H.; Chang, Y. C.; Hong, M., E-mail: raynien@phys.nthu.edu.tw, E-mail: mhong@phys.ntu.edu.tw [Graduate Institute of Applied Physics and Department of Physics, National Taiwan University, Taipei 10617, Taiwan (China); Chu, R. L.; Chang, Y. H. [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China)] [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Lee, M. Y.; Hong, P. F.; Chen, Min-Cheng [National Nano Device Laboratories, Hsinchu 30076, Taiwan (China)] [National Nano Device Laboratories, Hsinchu 30076, Taiwan (China); Kwo, J., E-mail: raynien@phys.nthu.edu.tw, E-mail: mhong@phys.ntu.edu.tw [Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

    2013-12-16T23:59:59.000Z

    Self-aligned inversion-channel In{sub 0.53}Ga{sub 0.47}As metal-oxide-semiconductor field-effect-transistors (MOSFETs) have been fabricated using the gate dielectrics of in-situ directly atomic-layer-deposited (ALD) HfO{sub 2} followed by ALD-Al{sub 2}O{sub 3}. There were no surface pretreatments and no interfacial passivation/barrier layers prior to the ALD. TiN/Al{sub 2}O{sub 3} (4?nm)/HfO{sub 2} (1?nm)/In{sub 0.53}Ga{sub 0.47}As/InP MOS capacitors exhibited well-behaved capacitance-voltage characteristics with true inversion behavior, low leakage current densities of ?10{sup ?8}?A/cm{sup 2} at ±1?MV/cm, and thermodynamic stability at high temperatures. Al{sub 2}O{sub 3} (3?nm)/HfO{sub 2} (1?nm)/In{sub 0.53}Ga{sub 0.47}As MOSFETs of 1 ?m gate length, with 700?°C–800?°C rapid thermal annealing in source/drain activation, have exhibited high extrinsic drain current (I{sub D}) of 1.5?mA/?m, transconductance (G{sub m}) of 0.84 mS/?m, I{sub ON}/I{sub OFF} of ?10{sup 4}, low sub-threshold swing of 103?mV/decade, and field-effect electron mobility of 1100 cm{sup 2}/V?·?s. The devices have also achieved very high intrinsic I{sub D} and G{sub m} of 2?mA/?m and 1.2?mS/?m, respectively.

  1. 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.

  2. Method for producing metal oxide aerogels

    DOE Patents [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.

  3. 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

  4. IEEE PHOTONICS TECHNOLOGY LETTERS, VOL. 16, NO. 6, JUNE 2001 623 MetalSemiconductorMetal Traveling-Wave

    E-Print Network [OSTI]

    Bowers, John

    in high-power distributed PD array or terahertz signal generation. Index Terms--Low-temperature-grown Ga­Semiconductor­Metal Traveling-Wave Photodetectors Jin-Wei Shi, Kian-Giap Gan, Yi-Jen Chiu, Yen-Hung Chen, Chi-Kuang Sun, Member-TWPD). Demonstrated devices were fabricated using low-temperature grown GaAs (LTG-GaAs). In order to achieve high

  5. Metal oxide membranes for gas separation

    DOE Patents [OSTI]

    Anderson, M.A.; Webster, E.T.; Xu, Q.

    1994-08-30T23:59:59.000Z

    A method for formation of a microporous ceramic membrane onto a porous support includes placing a colloidal suspension of metal oxide particles on one side of the porous support and exposing the other side of the porous support to a drying stream of gas or a reactive gas stream so that the particles are deposited on the drying side of the support as a gel. The gel so deposited can be sintered to form a supported ceramic membrane having mean pore sizes less than 30 Angstroms and useful for ultrafiltration, reverse osmosis, or gas separation. 4 figs.

  6. Metal oxide membranes for gas separation

    DOE Patents [OSTI]

    Anderson, Marc A. (Madison, WI); Webster, Elizabeth T. (Madison, WI); Xu, Qunyin (Plainsboro, NJ)

    1994-01-01T23:59:59.000Z

    A method for permformation of a microporous ceramic membrane onto a porous support includes placing a colloidal suspension of metal oxide particles on one side of the porous support and exposing the other side of the porous support to a drying stream of gas or a reactive gas stream so that the particles are deposited on the drying side of the support as a gel. The gel so deposited can be sintered to form a supported ceramic membrane having mean pore sizes less than 30 Angstroms and useful for ultrafiltration, reverse osmosis, or gas separation.

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

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

    Monolithic Metal Oxide based Composite Nanowire Lean NO x Emission Control Catalysts Pu-Xian Gao Department of Chemical, Materials and Biomolecular Engineering & Institute of...

  8. (Data in thousand metric tons of silicon content unless otherwise noted) Domestic Production and Use: Estimated value of silicon alloys and metal (excluding semiconductor-and solar-

    E-Print Network [OSTI]

    Production and Use: Estimated value of silicon alloys and metal (excluding semiconductor- and solar- grade and aluminum alloys and the chemical industry. The semiconductor and solar industries, which manufacture chips China, 49%; Russia, 20

  9. Nano- sized strontium titanate metal oxide semiconductor oxygen gas sensors.

    E-Print Network [OSTI]

    Hu, Ying.

    2008-01-01T23:59:59.000Z

    ??The project focuses on strontium titanate (SrTiO3> material, a very important material for oxygen sensors. The advantages of the material are low cost and stability… (more)

  10. Metal Oxide Semiconductor Nanoparticles Open the Door to New Medical

    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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces andMapping theEnergy StorageAdvanced Materials AdvancedInnovations | Argonne

  11. Metal Oxide Semiconductor Nanoparticles Pave the Way for Medical Innovation

    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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces andMapping theEnergy StorageAdvanced Materials AdvancedInnovations |

  12. 1/f noise in semiconductor and metal nanocrystal solids

    SciTech Connect (OSTI)

    Liu, Heng, E-mail: leophy@gmail.com; Lhuillier, Emmanuel, E-mail: emmanuel.lhuillier@espci.fr; Guyot-Sionnest, Philippe [James Franck Institute, The University of Chicago, 929 E 57th Street, Chicago, Illinois 60637 (United States)

    2014-04-21T23:59:59.000Z

    Electrical 1/f noise is measured in thin films of CdSe, CdSe/CdS, ZnO, HgTe quantum dots and Au nanocrystals. The 1/f noise, normalized per nanoparticle, shows no systematic dependence on the nanoparticle material and the coupling material. However, over 10 orders of magnitude, it correlates well with the nearest neighbor conductance suggesting some universal magnitude of the 1/f noise in these granular conductors. In the hopping regime, the main mechanism of 1/f noise is determined to be mobility fluctuated. In the metallic regime obtained with gold nanoparticle films, the noise drops to a similar level as bulk gold films and with a similar temperature dependence.

  13. 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.

  14. 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.

  15. 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.

  16. Metal-insulator-semiconductor structure on low-temperature grown GaAs M. Young, W. Li, and T. P. Ma

    E-Print Network [OSTI]

    Woodall, Jerry M.

    Metal-insulator-semiconductor structure on low-temperature grown GaAs A. Chen,a M. Young, W. Li Received 28 July 2006; accepted 30 October 2006; published online 7 December 2006 The metal-insulator dielectrics and metal-insulator-semiconductor MIS structures; for ex- ample, in situ deposited Ga2O3 Gd2O3

  17. Prospects and merits of metal-clad semiconductor lasers from nearly UV to far IR

    E-Print Network [OSTI]

    Khurgin, Jacob B

    2015-01-01T23:59:59.000Z

    Using metal-clad (or plasmonic) waveguide structures in semiconductor lasers carries a promise of reduced size, threshold, and power consumption. This promise is put to a rigorous theoretical test, that takes into account increased waveguide loss, Auger recombination, and Purcell enhancement of spontaneous recombination. The conclusion is that purported benefits of metal waveguides are small to nonexistent for all the band-to-band and intersubband lasers operating from UV to Mid-IR range, with a prominent exception of far-IR and THz quantum cascade lasers. For these devices, however, metal waveguides already represent the state of the art, and the guiding mechanism in them has far more in common with a ubiquitous transmission line than with plasmonics.

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

    E-Print Network [OSTI]

    metals. A research team at the National Renewable Energy Laboratory (NREL) has demonstrated Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC. 1617 Cole BoulevardTransition metal oxide improves overall efficiency and maintains performance with inexpensive

  19. Transition metal-promoted oxygen ion conductors as oxidation catalyst

    SciTech Connect (OSTI)

    Liu, W.; Sarofim, A. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Chemical Engineering; Flytzani-Stephanopoulos, M. [Tufts Univ., Medford, MA (United States). Dept. of Chemical Engineering

    1994-12-31T23:59:59.000Z

    A novel metal oxide composite catalyst for the complete oxidation of carbon monoxide and hydrocarbons was prepared by combining oxygen ion conducting materials with active transition metals. The oxygen ion conductors used were typical fluorite-type oxides, such as ceria, zirconia, and others. Active base metal catalysts, such as copper, were used as additives to promote the catalytic properties of oxygen ion conductors. The intimate contact of the two kinds of materials gave rise to a highly active oxidation catalyst. On Cu-Ce-O composite catalysts, 95% of carbon monoxide was oxidized by air at {approximately} 100 C. Complete methane oxidation on the same catalyst took place at {approximately} 550 C. When the stoichiometric amount of sulfur dioxide was sued to oxidize carbon monoxide, 96% of sulfur dioxide was reduced to elemental sulfur at temperatures above 460 C with 99% of sulfur dioxide conversion. This type of composite catalyst also showed excellent resistance to water poisoning.

  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. Amorphous silicon enhanced metal-insulator-semiconductor contacts for silicon solar cells

    SciTech Connect (OSTI)

    Bullock, J., E-mail: james.bullock@anu.edu.au; Cuevas, A.; Yan, D. [Research School of Engineering, The Australian National University, Canberra, ACT 0200 (Australia); Demaurex, B.; Hessler-Wyser, A.; De Wolf, S. [Ecole Polytechnique Fédérale de Lausanne (EPFL), Institute of Micro Engineering (IMT), Photovoltaics and Thin Film Electronic Laboratory PVLab, Maladière 71b, CH-200 Neuchâtel (Switzerland)

    2014-10-28T23:59:59.000Z

    Carrier recombination at the metal-semiconductor contacts has become a significant obstacle to the further advancement of high-efficiency diffused-junction silicon solar cells. This paper provides the proof-of-concept of a procedure to reduce contact recombination by means of enhanced metal-insulator-semiconductor (MIS) structures. Lightly diffused n{sup +} and p{sup +} surfaces are passivated with SiO{sub 2}/a-Si:H and Al{sub 2}O{sub 3}/a-Si:H stacks, respectively, before the MIS contacts are formed by a thermally activated alloying process between the a-Si:H layer and an overlying aluminum film. Transmission/scanning transmission electron microscopy (TEM/STEM) and energy dispersive x-ray spectroscopy are used to ascertain the nature of the alloy. Idealized solar cell simulations reveal that MIS(n{sup +}) contacts, with SiO{sub 2} thicknesses of ?1.55?nm, achieve the best carrier-selectivity producing a contact resistivity ?{sub c} of ?3 m? cm{sup 2} and a recombination current density J{sub 0c} of ?40 fA/cm{sup 2}. These characteristics are shown to be stable at temperatures up to 350?°C. The MIS(p{sup +}) contacts fail to achieve equivalent results both in terms of thermal stability and contact characteristics but may still offer advantages over directly metallized contacts in terms of manufacturing simplicity.

  2. Route to transition metal carbide nanoparticles through cyanamide and metal oxides

    SciTech Connect (OSTI)

    Li, P.G. [Department of Physics, Center for Optoelectronics Materials and Devices, Zhejiang Sci-Tech University, Xiasha College Park, Hangzhou 310018 (China)], E-mail: peigangiphy@yahoo.com.cn; Lei, M.; Tang, W.H. [Department of Physics, Center for Optoelectronics Materials and Devices, Zhejiang Sci-Tech University, Xiasha College Park, Hangzhou 310018 (China)

    2008-12-01T23:59:59.000Z

    We have designed an efficient route to the synthesis of transition metal carbide nanoparticles starting from an organic reagent cyanamide and transition metal oxides. Four technologically important metal carbide nanoparticles such as tungsten carbide, niobium carbide, tantalum carbide and vanadium carbide were synthesized successfully at moderate temperatures. It is found that cyanamide is an efficient carburization reagent and that the metal oxides are completely transmitted into the corresponding carbide nanoparticles. A possible mechanism is proposed to explain the results of the reaction between cyanamide and the metal oxides.

  3. Production of pulsed, mass-selected beams of metal and semiconductor clusters

    SciTech Connect (OSTI)

    Kamalou, Omar; Rangama, Jimmy; Ramillon, Jean-Marc; Guinement, Patrick; Huber, Bernd A. [CIMAP, CEA-CNRS-ENSICaen-UCBN, Bv. Henry Becquerel (B.P. 5133), F-14070 Caen Cedex 05 (France)

    2008-06-15T23:59:59.000Z

    We report on the development of a beam line for mass-selected metal and semiconductor clusters. The cluster source combines the principles of plasma sputtering and gas condensation. Both techniques together allow to produce clusters in a wide size range. With the aid of a time-of-flight system, small clusters (i.e., Cu{sub n}{sup +}, n<100) are selected and pure beams containing only one cluster size are provided. For large clusters (containing several thousands of atoms), a beam with a narrow size distribution is obtained. A 90 deg. quadrupole deviator is used to separate charged clusters from neutral ones.

  4. 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.

  5. 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.

  6. Method and apparatus for the production of metal oxide powder

    DOE Patents [OSTI]

    Harris, Michael T. (Knoxville, TN); Scott, Timothy C. (Knoxville, TN); Byers, Charles H. (Oak Ridge, TN)

    1993-01-01T23:59:59.000Z

    The present invention provides a method for preparing metal oxide powder. A first solution, which is substantially organic, is prepared. A second solution, which is an aqueous solution substantially immiscible in the first solution, is prepared and delivered as drops to the first solution. The drops of the second solution are atomized by a pulsed electric field forming micro-drops of the second solution. Reagents in the first solution diffuse into and react with reactants in the micro-drops of the second solution forming metal hydroxide or oxalate particles. The metal hydroxide or metal oxalate particles are then recovered and dried to produce the metal oxide powder. An apparatus for preparing a metal oxide powder is also disclosed.

  7. Method and apparatus for the production of metal oxide powder

    DOE Patents [OSTI]

    Harris, Michael T. (Knoxville, TN); Scott, Timothy C. (Knoxville, TN); Byers, Charles H. (Oak Ridge, TN)

    1992-01-01T23:59:59.000Z

    The present invention provides a method for preparing metal oxide powder. A first solution, which is substantially organic, is prepared. A second solution, which is an aqueous solution substantially immiscible in the first solution, is prepared and delivered as drops to the first solution. The drops of the second solution are atomized by a pulsed electric field forming micro-drops of the second solution. Reagents in the first solution diffuse into and react with reactants in the micro-drops of the second solution forming metal hydroxide or oxalate particles. The metal hydroxide or metal oxalate particles are then recovered and dried to produce the metal oxide powder. An apparatus for preparing a metal oxide powder is also disclosed.

  8. Method and apparatus for the production of metal oxide powder

    DOE Patents [OSTI]

    Harris, M.T.; Scott, T.C.; Byers, C.H.

    1992-06-16T23:59:59.000Z

    The present invention provides a method for preparing metal oxide powder. A first solution, which is substantially organic, is prepared. A second solution, which is an aqueous solution substantially immiscible in the first solution, is prepared and delivered as drops to the first solution. The drops of the second solution are atomized by a pulsed electric field forming micro-drops of the second solution. Reagents in the first solution diffuse into and react with reactants in the micro-drops of the second solution forming metal hydroxide or oxalate particles. The metal hydroxide or metal oxalate particles are then recovered and dried to produce the metal oxide powder. An apparatus for preparing a metal oxide powder is also disclosed. 2 figs.

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

    SciTech Connect (OSTI)

    Benecha, E. M. [Department of Physics, University of South Africa, P.O. Box 392, UNISA 0003 Pretoria (South Africa); Lombardi, E. B., E-mail: lombaeb@unisa.ac.za [College of Graduate Studies, University of South Africa, P.O. Box 392, UNISA 0003 Pretoria (South Africa)

    2013-12-14T23:59:59.000Z

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

  10. 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...

  11. 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.``

  12. 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.

  13. Inert electrode containing metal oxides, copper and noble metal

    DOE Patents [OSTI]

    Ray, Siba P. (Murrysville, PA); Woods, Robert W. (New Kensington, PA); Dawless, Robert K. (Monroeville, PA); Hosler, Robert B. (Sarver, PA)

    2001-01-01T23:59:59.000Z

    A cermet composite material is made by treating at an elevated temperature a mixture comprising a compound of iron and a compound of at least one other metal, together with an alloy or mixture of copper and a noble metal. The alloy or mixture preferably comprises particles having an interior portion containing more copper than noble metal and an exterior portion containing more noble metal than copper. The noble metal is preferably silver. The cermet composite material preferably includes alloy phase portions and a ceramic phase portion. At least part of the ceramic phase portion preferably has a spinel structure.

  14. Inert electrode containing metal oxides, copper and noble metal

    DOE Patents [OSTI]

    Ray, Siba P. (Murrysville, PA); Woods, Robert W. (New Kensington, PA); Dawless, Robert K. (Monroeville, PA); Hosler, Robert B. (Sarver, PA)

    2000-01-01T23:59:59.000Z

    A cermet composite material is made by treating at an elevated temperature a mixture comprising a compound of iron and a compound of at least one other metal, together with an alloy or mixture of copper and a noble metal. The alloy or mixture preferably comprises particles having an interior portion containing more copper than noble metal and an exterior portion containing more noble metal than copper. The noble metal is preferably silver. The cermet composite material preferably includes alloy phase portions and a ceramic phase portion. At least part of the ceramic phase portion preferably has a spinel structure.

  15. 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

  16. E-Print Network 3.0 - ambient oxidizer concentration Sample Search...

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

    of anneals in ammonia on the interface trap density near the band edges in 4Hsilicon carbide metal-oxide-semiconductor capacitors Summary: -silicon carbide...

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Proton-induced transient effects in a metal-semiconductor-metal (MSM) photodetector for optical-based data transfer

    SciTech Connect (OSTI)

    Marshall, C.J. [NASA/GSFC, Greenbelt, MD (United States)] [NASA/GSFC, Greenbelt, MD (United States); [NRL, Washington, DC (United States); Marshall, P.W.; Carts, M.A. [NRL, Washington, DC (United States)] [NRL, Washington, DC (United States); [SFA, Largo, MD (United States); Reed, R.A.; LaBel, K.A. [NASA/GSFC, Greenbelt, MD (United States)] [NASA/GSFC, Greenbelt, MD (United States)

    1998-12-01T23:59:59.000Z

    The authors present a study of proton transient effects in metal-semiconductor-metal (MSM) photodetectors, which demonstrates their inherent advantage for minimizing Single Event Effects (SEEs) in proton environments. Upset mechanisms are characterized for 830 nm GaAs and 1300 nm InGaAs detectors. Only protons incident at grazing angles are likely to cause a bit errors by direct ionization. The MSM technology appears to be a more robust to single bit errors than thicker 1300 nm p-i-n diode structures which the authors have previously shown to be susceptible to errors from direct ionization events at all angles, and also are relatively high optical powders. For a given receiver, the relative contributions of direct ionization and nuclear reaction upset mechanisms at a specific data rate and optical power are determined by the geometry of the charge collection volume of the detector. The authors show that state-of-the-art p-i-n detectors can also display a reduced sensitivity to direct ionization by incident protons except at grazing angles.

  2. Electron-Phonon Coupling and Thermal Conductance at a Metal-Semiconductor Interface: First-principles Analysis

    E-Print Network [OSTI]

    Sadasivam, Sridhar; Fisher, Timothy S

    2015-01-01T23:59:59.000Z

    The mechanism of heat transfer and the contribution of electron-phonon coupling to thermal conductance of a metal-semiconductor interface remains unclear in the present literature. We report ab initio simulations of a technologically important titanium silicide (metal) - silicon (semiconductor) interface to estimate the Schottky barrier height (SBH), and the strength of electron-phonon and phonon-phonon heat transfer across the interface. The electron and phonon dispersion relations of TiSi$_2$ with C49 structure and the TiSi$_2$-Si interface are obtained using first-principles calculations within the density functional theory (DFT) framework. These are used to estimate electron-phonon linewidths and the associated Eliashberg function that quantifies coupling. We show that the coupling strength of electrons with interfacial phonon modes is of the same order of magnitude as coupling of electrons to phonon modes in the bulk metal, and its contribution to electron-phonon interfacial conductance is comparable to ...

  3. Low interfacial trap density and sub-nm equivalent oxide thickness in In{sub 0.53}Ga{sub 0.47}As (001) metal-oxide-semiconductor devices using molecular beam deposited HfO{sub 2}/Al{sub 2}O{sub 3} as gate dielectrics

    SciTech Connect (OSTI)

    Chu, L. K. [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Katholieke Universiteit Leuven, 3001 Leuven (Belgium); Merckling, C.; Dekoster, J.; Caymax, M. [Interuniversity Microelectronics Center (IMEC vzw), 3001 Leuven (Belgium); Alian, A.; Heyns, M. [Katholieke Universiteit Leuven, 3001 Leuven (Belgium); Interuniversity Microelectronics Center (IMEC vzw), 3001 Leuven (Belgium); Kwo, J. [Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan (China); Hong, M. [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

    2011-07-25T23:59:59.000Z

    We investigated the passivation of In{sub 0.53}Ga{sub 0.47}As (001) surface by molecular beam epitaxy techniques. After growth of strained In{sub 0.53}Ga{sub 0.47}As on InP (001) substrate, HfO{sub 2}/Al{sub 2}O{sub 3} high-{kappa} oxide stacks have been deposited in-situ after surface reconstruction engineering. Excellent capacitance-voltage characteristics have been demonstrated along with low gate leakage currents. The interfacial density of states (D{sub it}) of the Al{sub 2}O{sub 3}/In{sub 0.53}Ga{sub 0.47}As interface have been revealed by conductance measurement, indicating a downward D{sub it} profile from the energy close to the valence band (medium 10{sup 12} cm{sup -2}eV{sup -1}) towards that close to the conduction band (10{sup 11} cm{sup -2}eV{sup -1}). The low D{sub it}'s are in good agreement with the high Fermi-level movement efficiency of greater than 80%. Moreover, excellent scalability of the HfO{sub 2} has been demonstrated as evidenced by the good dependence of capacitance oxide thickness on the HfO{sub 2} thickness (dielectric constant of HfO{sub 2}{approx}20) and the remained low D{sub it}'s due to the thin Al{sub 2}O{sub 3} passivation layer. The sample with HfO{sub 2} (3.4 nm)/Al{sub 2}O{sub 3} (1.2 nm) as the gate dielectrics has exhibited an equivalent oxide thickness of {approx}0.93 nm.

  4. 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.

  5. Carbon monoxide oxidation over three different states of copper: Development of a model metal oxide catalyst

    SciTech Connect (OSTI)

    Jernigan, G.G. [California Univ., Berkeley, CA (United States). Dept. of Chemistry; [Lawrence Berkeley Lab., CA (United States). Materials and Chemical Sciences Div.

    1994-10-01T23:59:59.000Z

    Carbon monoxide oxidation was performed over the three different oxidation states of copper -- metallic (Cu), copper (I) oxide (Cu{sub 2}O), and copper (II) oxide (CuO) as a test case for developing a model metal oxide catalyst amenable to study by the methods of modern surface science and catalysis. Copper was deposited and oxidized on oxidized supports of aluminum, silicon, molybdenum, tantalum, stainless steel, and iron as well as on graphite. The catalytic activity was found to decrease with increasing oxidation state (Cu > Cu{sub 2}O > CuO) and the activation energy increased with increasing oxidation state (Cu, 9 kcal/mol < Cu{sub 2}O, 14 kcal/mol < CuO, 17 kcal/mol). Reaction mechanisms were determined for the different oxidation states. Lastly, NO reduction by CO was studied. A Cu and CuO catalyst were exposed to an equal mixture of CO and NO at 300--350 C to observe the production of N{sub 2} and CO{sub 2}. At the end of each reaction, the catalyst was found to be Cu{sub 2}O. There is a need to study the kinetics of this reaction over the different oxidation states of copper.

  6. 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.

  7. 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.

  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

    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

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. Method to determine the position-dependant metal correction factor for dose-rate equivalent laser testing of semiconductor devices

    DOE Patents [OSTI]

    Horn, Kevin M.

    2013-07-09T23:59:59.000Z

    A method reconstructs the charge collection from regions beneath opaque metallization of a semiconductor device, as determined from focused laser charge collection response images, and thereby derives a dose-rate dependent correction factor for subsequent broad-area, dose-rate equivalent, laser measurements. The position- and dose-rate dependencies of the charge-collection magnitude of the device are determined empirically and can be combined with a digital reconstruction methodology to derive an accurate metal-correction factor that permits subsequent absolute dose-rate response measurements to be derived from laser measurements alone. Broad-area laser dose-rate testing can thereby be used to accurately determine the peak transient current, dose-rate response of semiconductor devices to penetrating electron, gamma- and x-ray irradiation.

  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. 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.

  16. 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.

  17. 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 ...

  18. 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.

  19. Diamond logic inverter with enhancement-mode metal-insulator-semiconductor field effect transistor

    SciTech Connect (OSTI)

    Liu, J. W., E-mail: liu.jiangwei@nims.go.jp [International Center for Young Scientists (ICYS), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Liao, M. Y.; Imura, M. [Optical and Electronic Materials Unit, NIMS, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Watanabe, E.; Oosato, H. [Nanofabrication Platform, NIMS, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Koide, Y., E-mail: koide.yasuo@nims.go.jp [Optical and Electronic Materials Unit, NIMS, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Nanofabrication Platform, NIMS, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Center of Materials Research for Low Carbon Emission, NIMS, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)

    2014-08-25T23:59:59.000Z

    A diamond logic inverter is demonstrated using an enhancement-mode hydrogenated-diamond metal-insulator-semiconductor field effect transistor (MISFET) coupled with a load resistor. The gate insulator has a bilayer structure of a sputtering-deposited LaAlO{sub 3} layer and a thin atomic-layer-deposited Al{sub 2}O{sub 3} buffer layer. The source-drain current maximum, extrinsic transconductance, and threshold voltage of the MISFET are measured to be ?40.7?mA·mm{sup ?1}, 13.2?±?0.1?mS·mm{sup ?1}, and ?3.1?±?0.1?V, respectively. The logic inverters show distinct inversion (NOT-gate) characteristics for input voltages ranging from 4.0 to ?10.0?V. With increasing the load resistance, the gain of the logic inverter increases from 5.6 to as large as 19.4. The pulse response against the high and low input voltages shows the inversion response with the low and high output voltages.

  20. 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.

  1. 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.

  2. 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

    transition metal oxides. Acknowledgment This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy,

  3. 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

  4. 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.

  5. 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)

  6. Synthesis, Characterization, and Ultrafast Dynamics of Metal, Metal Oxide, and Semiconductor Nanomaterials

    E-Print Network [OSTI]

    Wheeler, Damon Andreas

    2013-01-01T23:59:59.000Z

    electron storage, electrochromic, and photoelectrochromicV. Thin Solid Films Electrochromic and photoelectrochemical

  7. Synthesis, Characterization, and Ultrafast Dynamics of Metal, Metal Oxide, and Semiconductor Nanomaterials

    E-Print Network [OSTI]

    Wheeler, Damon Andreas

    2013-01-01T23:59:59.000Z

    purity hydrogen gas (Praxair). 5.3.3 Electron Microscopy (purity hydrogen gas (Praxair). 6.3.3 UV-Vis, Electron

  8. Synthesis, Characterization, and Ultrafast Dynamics of Metal, Metal Oxide, and Semiconductor Nanomaterials

    E-Print Network [OSTI]

    Wheeler, Damon Andreas

    2013-01-01T23:59:59.000Z

    cancer treatment, sensors, lasers, and solar cells. Onedetectors, solar energy conversion, sensors, and manydetectors, solar energy conversion, lasers, and sensors. A

  9. Synthesis, Characterization, and Ultrafast Dynamics of Metal, Metal Oxide, and Semiconductor Nanomaterials

    E-Print Network [OSTI]

    Wheeler, Damon Andreas

    2013-01-01T23:59:59.000Z

    S. R. ; Cowan, A. J. ; Barroso, M. ; Sivula, K. ; Ye, J. ;3861. (167) Pendlebury, S. R. ; Barroso, M. ; Cowan, A. J. ;+. (199) Pendlebury, S. ; Barroso, M. ; Cowan, A. ; Sivula,

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Mechanistic Studies of Charge Injection from Metallic Electrodes into Organic Semiconductors Mediated by Ionic Functionalities: Final Report

    SciTech Connect (OSTI)

    Nguyen, Thuc-Quyen [UCSB; Bazan, Guillermo [UCSB; Mikhailovsky, Alexander [UCSB

    2014-04-15T23:59:59.000Z

    Metal-organic semiconductor interfaces are important because of their ubiquitous role in determining the performance of modern electronics such as organic light emitting diodes (OLEDs), fuel cells, batteries, field effect transistors (FETs), and organic solar cells. Interfaces between metal electrodes required for external wiring to the device and underlying organic structures directly affect the charge carrier injection/collection efficiency in organic-based electronic devices primarily due to the mismatch between energy levels in the metal and organic semiconductor. Environmentally stable and cost-effective electrode materials, such as aluminum and gold typically exhibit high potential barriers for charge carriers injection into organic devices leading to increased operational voltages in OLEDs and FETs and reduced charge extraction in photovoltaic devices. This leads to increased power consumption by the device, reduced overall efficiency, and decreased operational lifetime. These factors represent a significant obstacle for development of next generation of cheap and energy-efficient components based on organic semiconductors. It has been noticed that introduction of organic materials with conjugated backbone and ionic pendant groups known as conjugated poly- and oligoelectrolytes (CPEs and COEs), enables one to reduce the potential barriers at the metal-organic interface and achieve more efficient operation of a device, however exact mechanisms of the phenomenon have not been understood. The goal of this project was to delineate the function of organic semiconductors with ionic groups as electron injection layers. The research incorporated a multidisciplinary approach that encompassed the creation of new materials, novel processing techniques, examination of fundamental electronic properties and the incorporation of the resulting knowledgebase into development of novel organic electronic devices with increased efficiency, environmental stability, and reduced cost. During the execution of the project, main efforts were focused on the synthesis of new charge-bearing organic materials, such as CPEs and COEs, and block copolymers with neutral and ionic segments, studies of mechanisms responsible for the charge injection modulation in devices with ionic interlayers, and use of naturally occurring charged molecules for creation of enhanced devices. The studies allowed PIs to demonstrate the usefulness of the proposed approach for the improvement of operational parameters in model OLED and FET systems resulting in increased efficiency, decreased contact resistance, and possibility to use stable metals for fabrication of device electrodes. The successful proof-of-the-principle results potentially promise development of light-weight, low fabrication cost devices which can be used in consumer applications such as displays, solar cells, and printed electronic devices. Fundamental mechanisms responsible for the phenomena observed have been identified thus advancing the fundamental knowledgebase.

  17. 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.

  18. 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.

  19. 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...

  20. Electrodepositionof Metal Alloyand Mixed Oxide Films Usinga Single-PrecursorTetranuclearCopper-NickelComplex

    E-Print Network [OSTI]

    Kounaves, Samuel P.

    Compositionally uniform mixed metals, metal oxides, and alloys are used extensively as corrosion protective and catalysts. I-~For example, nickel-containing oxides and alloys are used for oxidative protection of very. Although Cu-Ni alloy deposition has been stud- ied for many years, none of the previous approaches has led

  1. 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

  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. Superhydrophobic Metal-Oxide Thin Film Coatings - 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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security AdministrationcontrollerNanocrystalline Gallium OxideSuminDeposition of Metal FilmsIndustrial

  4. 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

  5. Nonadiabatic electron transfer at the nanoscale tin-oxide semiconductor/aqueous solution interface

    E-Print Network [OSTI]

    are of considerable interest in the context of dye-sensitized liquid-junction cells for sunlight-to-electrical- energy forward and back electron transfer reactions involving molecular dyes and wide bandgap semiconductors conversion ­ for example, Grätzel cells.1­3 We have examined the kinetics of back electron transfer (b

  6. Metal-based turn-on fluorescent probes for nitric oxide sensing

    E-Print Network [OSTI]

    Lim, Mi Hee

    2006-01-01T23:59:59.000Z

    Chapter 1. Metal-Based Turn-On Fluorescent Probes for Sensing Nitric Oxide. Nitric oxide, a reactive free radical, regulates a variety of biological processes. The absence of tools to detect NO directly, rapidly, specifically ...

  7. E-Print Network 3.0 - alkaline-earth metal oxides Sample Search...

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

    differ in the nature of the angle... ). Weidner and Hamaya (1983) observed that the transition-metal oxides and the alkaline-earth oxides fail... ... Source: Price, G. David -...

  8. Bipolar plating of metal contacts onto oxide interconnection for solid oxide electrochemical cell

    DOE Patents [OSTI]

    Isenberg, Arnold O. (Forest Hills Boro, PA)

    1987-01-01T23:59:59.000Z

    Disclosed is a method of forming an adherent metal deposit on a conducting layer of a tube sealed at one end. The tube is immersed with the sealed end down into an aqueous solution containing ions of the metal to be deposited. An ionically conducting aqueous fluid is placed inside the tube and a direct current is passed from a cathode inside the tube to an anode outside the tube. Also disclosed is a multi-layered solid oxide fuel cell tube which consists of an inner porous ceramic support tube, a porous air electrode covering the support tube, a non-porous electrolyte covering a portion of the air electrode, a non-porous conducting interconnection covering the remaining portion of the electrode, and a metal deposit on the interconnection.

  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. Metal silicide nanoelectromechanical relays for low power applications.

    E-Print Network [OSTI]

    Stanford University, Dept. of Electrical; Engineering

    2014-01-01T23:59:59.000Z

    ??ABSTRACT Scaling down the metal-oxide-semiconductor field effect transistor (MOSFET) has continuously brought lower cost, higher density and increased performance since the 1960s. However, as MOS… (more)

  11. Total oxidation of carbon monoxide and methane over transition metal-fluorite oxide composite catalysts. I. Catalyst composition and activity

    SciTech Connect (OSTI)

    Liu, W.; Flytzani-Stephanopoulos, F. [Tufts Univ., Medford, MA (United States)] [Tufts Univ., Medford, MA (United States)

    1995-05-01T23:59:59.000Z

    A novel metal oxide composite catalyst for the total oxidation of carbon monoxide and methane was prepared by combining fluorite oxides with active transition metals. The fluorite oxides, such as ceria and zirconia, are oxygen-ion-conducting materials having catalytic properties usually at high temperatures. Active base metal catalysts, such as copper, were used as additives to promote the catalytic properties of these oxides. The contact of the two types of materials gave rise to a high active oxidation catalyst. At a space velocity of about 42,000 h{sup {minus}1}, complete carbon monoxide oxidation in air occurred at room temperature on the Au{sub 0.05}[Ce(La)]{sub 0.95}L{sub x} catalyst and at ca. 100{degrees}C on Cu-Ce-O composite catalysts. At the same space velocity, total oxidation of methane on the Cu-Ce-O catalyst doped with La{sub 2}O{sub 3} or SrO took place at ca. 550{degrees}C. The specific carbon monoxide oxidation activity of the Cu-Ce-O catalyst was several orders of magnitude higher than that of conventional copper-based catalysts and comparable or superior to platinum catalysts. This type of composite catalyst also showed excellent resistance to water vapor poisoning. The enhanced catalyst activity and stability resulted from strong interaction of the transition metal and fluorite oxide materials. 44 refs., 14 figs., 5 tabs.

  12. Studies on supported metal oxide-oxide support interactions (an incorporation model)

    SciTech Connect (OSTI)

    Yi Chen; Lin Dong; Y.S. Jin; Bing Xu; Weijie Ji [Nanjing Univ. (China)

    1996-12-31T23:59:59.000Z

    XRD, XPS, SSIMS, LRS, and FT-IR are used to explore the valency, composition and structure of the dispersed metal oxide species on supports with different structures, i.e., on ceria and {gamma}-alumina. The results indicated that the dispersion of various ionic compounds are proceeded by the incorporation of the metal cations into the surface vacant sites on the support provided that the loading amounts of the compounds are not higher than their dispersion capacities. The key factors determining the dispersion capacities of the ionic compounds are: (1) the surface structure of the support which determines the size and number of the vacant sites available. (2) the valency of the dispersed ionic compound and the size of the anion, from which the shielding effect of the capping anion(s) can be evaluated, and (3) the sizes of the dispersed cations and the vacant sites on the surface, from which the sites can be used for incorporation can be identified. The Quantitative results deduced from the incorporation model and from the independent experiments are consistent, providing further evidence that the model captures the essentials of the interactions between the dispersed metal oxide and support.

  13. 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).

  14. Photo-response of a P3HT:PCBM blend in metal-insulator-semiconductor capacitors

    SciTech Connect (OSTI)

    Devynck, M.; Rostirolla, B.; Watson, C. P.; Taylor, D. M., E-mail: d.m.taylor@bangor.ac.uk [School of Electronic Engineering, Bangor University, Dean Street, Bangor, Gwynedd LL57 1UT (United Kingdom)

    2014-11-03T23:59:59.000Z

    Metal-insulator-semiconductor capacitors are investigated, in which the insulator is cross-linked polyvinylphenol and the active layer a blend of poly(3-hexylthiophene), P3HT, and the electron acceptor [6,6]-phenyl-C{sub 61}-butyric acid methyl ester (PCBM). Admittance spectra and capacitance-voltage measurements obtained in the dark both display similar behaviour to those previously observed in P3HT-only devices. However, the photo-capacitance response is significantly enhanced in the P3HT:PCBM case, where exciton dissociation leads to electron transfer into the PCBM component. The results are consistent with a network of PCBM aggregates that is continuous through the film but with no lateral interconnection between the aggregates at or near the blend/insulator interface.

  15. Electron Transport Behavior on Gate Length Scaling in Sub-50 nm GaAs Metal Semiconductor Field Effect Transistors

    SciTech Connect (OSTI)

    Han, Jaeheon [Department of Electronic Engineering, Kangnam University, 111 Gugal-dong, Giheung-gu, Yongin-city, Gyeonggi-do, Korea 446-702 (Korea, Republic of)

    2011-12-23T23:59:59.000Z

    Short channel GaAs Metal Semiconductor Field Effect Transistors (MESFETs) have been fabricated with gate length to 20 nm, in order to examine the characteristics of sub-50 nm MESFET scaling. Here the rise in the measured transconductance is mainly attributed to electron velocity overshoot. For gate lengths below 40 nm, however, the transconductance drops suddenly. The behavior of velocity overshoot and its degradation is investigated and simulated by using a transport model based on the retarded Langevin equation (RLE). This indicates the existence of a minimum acceleration length needed for the carriers to reach the overshoot velocity. The argument shows that the source resistance must be included as an internal element, or appropriate boundary condition, of relative importance in any model where the gate length is comparable to the inelastic mean free path of the carriers.

  16. 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.

  17. 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.

  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. 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...

  20. 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.

  1. 2012 DEFECTS IN SEMICONDUCTORS GORDON RESEARCH CONFERENCE, AUGUST 12-17, 2012

    SciTech Connect (OSTI)

    GLASER, EVAN

    2012-08-17T23:59:59.000Z

    The meeting shall strive to develop and further the fundamental understanding of defects and their roles in the structural, electronic, optical, and magnetic properties of bulk, thin film, and nanoscale semiconductors and device structures. Point and extended defects will be addressed in a broad range of electronic materials of particular current interest, including wide bandgap semiconductors, metal-oxides, carbon-based semiconductors (e.g., diamond, graphene, etc.), organic semiconductors, photovoltaic/solar cell materials, and others of similar interest. This interest includes novel defect detection/imaging techniques and advanced defect computational methods.

  2. 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.

  3. 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

  4. Copper-induced oxidative stress in three-spined stickleback : relationship with hepatic metal levels

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    contamination of aquatic ecosystems by heavy metals. Among them, copper is a widespread pollutant found, 1999). Although this metal is a required element, high concentrations appear to be toxic to freshwater1 Copper-induced oxidative stress in three-spined stickleback : relationship with hepatic metal

  5. Thermal ionization induced metal-semiconductor transition and room temperature ferromagnetism in trivalent doped ZnO codoped with lithium

    SciTech Connect (OSTI)

    Sivagamasundari, A.; Chandrasekar, S.; Pugaze, R.; Kannan, R., E-mail: kannan@pec.edu [Department of Physics, Pondicherry Engineering College, Puducherry 605 014 (India); Rajagopan, S. [Department of Chemistry, Pondicherry Engineering College, Puducherry 605 014 (India)

    2014-03-07T23:59:59.000Z

    Thermal ionization induced metallic to semiconductor (MST) transition occurring at 460?K for Zn{sub 0.97}Al{sub 0.03}O, 463?K for Zn{sub 0.94}Al{sub 0.03}Li{sub 0.03}O, and 503?K for Zn{sub 0.91}Al{sub 0.03}Li{sub 0.03}Mn{sub 0.03}O has been found in the sol-gel synthesized (using hexamethylenetetramine), trivalent doped (Al, Mn) ZnO codoped with lithium. Increase in the thermally ionized carrier concentration due to Al doping is responsible for near band edge (NBE) peak shift causing Fermi level to move into conduction band making it metallic consistent with resistivity results. Free carrier (thermally activated) neutralization with ionized donor is responsible for semiconducting nature, which is supported from the free carrier screening produced energy shift in the NBE of photoluminescence peak. Furthermore, independently band gap shrinkage is also obtained from UV-Visible studies confirming localization induced MST. An anti-correlation is found between defect density (DLE) and room temperature ferromagnetism (RTFM) indicating intrinsic defects are not directly responsible for RTFM.

  6. Low temperature production of large-grain polycrystalline semiconductors

    DOE Patents [OSTI]

    Naseem, Hameed A. (Fayetteville, AR); Albarghouti, Marwan (Loudonville, NY)

    2007-04-10T23:59:59.000Z

    An oxide or nitride layer is provided on an amorphous semiconductor layer prior to performing metal-induced crystallization of the semiconductor layer. The oxide or nitride layer facilitates conversion of the amorphous material into large grain polycrystalline material. Hence, a native silicon dioxide layer provided on hydrogenated amorphous silicon (a-Si:H), followed by deposited Al permits induced crystallization at temperatures far below the solid phase crystallization temperature of a-Si. Solar cells and thin film transistors can be prepared using this method.

  7. 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.

  8. Reactivity of biogenic manganese oxide for metal sequestration and photochemistry: Computational solid state physics study

    SciTech Connect (OSTI)

    Kwon, K.D.; Sposito, G.

    2010-02-01T23:59:59.000Z

    Many microbes, including both bacteria and fungi, produce manganese (Mn) oxides by oxidizing soluble Mn(II) to form insoluble Mn(IV) oxide minerals, a kinetically much faster process than abiotic oxidation. These biogenic Mn oxides drive the Mn cycle, coupling it with diverse biogeochemical cycles and determining the bioavailability of environmental contaminants, mainly through strong adsorption and redox reactions. This mini review introduces recent findings based on quantum mechanical density functional theory that reveal the detailed mechanisms of toxic metal adsorption at Mn oxide surfaces and the remarkable role of Mn vacancies in the photochemistry of these minerals.

  9. 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.

  10. Oxide-based method of making compound semiconductor films and making related electronic devices

    DOE Patents [OSTI]

    Kapur, Vijay K. (Tarzana, CA); Basol, Bulent M. (Manhattan Beach, CA); Leidholm, Craig R. (Woodland Hills, CA); Roe, Robert A. (Glendale, CA)

    2000-01-01T23:59:59.000Z

    A method for forming a compound film includes the steps of preparing a source material, depositing the source material on a base and forming a preparatory film from the source material, heating the preparatory film in a suitable atmosphere to form a precursor film, and providing suitable material to said precursor film to form the compound film. The source material includes oxide-containing particles including Group IB and IIIA elements. The precursor film includes non-oxide Group IB and IIIA elements. The compound film includes a Group IB-IIIA-VIA compound. The oxides may constitute greater than about 95 molar percent of the Group IB elements and greater than about 95 molar percent of the Group IIIA elements in the source material. Similarly, non-oxides may constitute greater than about 95 molar percent of the Group IB elements and greater than about 95 molar percent of the Group IIIA elements in the precursor film. The molar ratio of Group IB to Group IIIA elements in the source material may be greater than about 0.6 and less than about 1.0, or substantially greater that 1.0, in which case this ratio in the compound film may be reduced to greater than about 0.6 and less than about 1.0. The source material may be prepared as an ink from particles in powder form. The oxide-containing particles may include a dopant, as may the compound film. Compound films including a Group IIB-IVA-VA compound may be substituted using appropriate substitutions in the method. The method, also, is applicable to fabrication of solar cells and other electronic devices.

  11. Synchrotron x-ray reflectivity study of oxidation/passivation of copper and silicon.

    SciTech Connect (OSTI)

    Chu, Y.; Nagy, Z.; Parkhutik, V.; You, H.

    1999-07-21T23:59:59.000Z

    Synchrotron x-ray-scattering technique studies of copper and silicon electrochemical interfaces are reported. These two examples illustrate the application of synchrotron x-ray techniques for oxidation, passivation, and dissolution of metals and semiconductors.

  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)

    for Improved Performance. Thin Metal Oxide Films to Modify a Window Layer in CdTe-Based Solar Cells for Improved Performance. Abstract: We report on CdSCdTe photovoltaic devices...

  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. 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.

  15. 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.

  16. Characterization of metal oxide layers grown on CVD graphene

    SciTech Connect (OSTI)

    Matsubayashi, Akitomo; Abel, Joseph; Prasad Sinha, Dhiraj; Lee, Ji Ung; LaBella, Vincent P. [College of Nanoscale Science and Engineering, University at Albany, SUNY, Albany, New York 12203 (United States)

    2013-03-15T23:59:59.000Z

    Growth of a fully oxidized aluminum oxide layer with low surface roughness on graphene grown by chemical vapor deposition is demonstrated. This is accomplished by the deposition of a 0.2 nm thick titanium seed layer on the graphene prior to the deposition of the aluminum under ultra high vacuum conditions, which was subsequently oxidized. The stoichiometry and surface roughness of the oxide layers were measured for a range of titanium and aluminum depositions utilizing ex situ x-ray photoelectron spectrometry and atomic force microscopy. These fully oxidized films are expected to produce good dielectric layers for use in graphene based electronic devices.

  17. 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.

  18. 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

  19. 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.

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

    DOE Patents [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.

  1. Photoelectron Imaging Spectroscopic Investigations of Transition Metal Silicides and Oxides.

    E-Print Network [OSTI]

    Gunaratne, K. Don

    2012-01-01T23:59:59.000Z

    ??This dissertation presents the experimental progress in the use of photoelectron imaging spectroscopy to probe the electronic structure of negatively charged transition metal silicides and… (more)

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

    DOE Patents [OSTI]

    Holcombe, C.E.; Dykes, N.L.; Tiegs, T.N.

    1992-10-13T23:59:59.000Z

    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.

  3. 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.

  4. CHEMISTRY OF SO{sub 2} ON MODEL METAL AND OXIDE CATALYSTS: PHOTOEMISSION AND XANES STUDIES

    SciTech Connect (OSTI)

    RODRIGUEZ,J.A.; JIRSAK,T.; CHATURVEDI,S.; HRBEK,J.; FREITAG,A.; LARESE,J.Z.

    2000-07-09T23:59:59.000Z

    High-resolution synchrotron based photoemission and x-ray absorption spectroscopy have been used to study the interaction of SO{sub 2} with a series of metals and oxides. The chemistry of SO{sub 2} on metal surfaces is rich. At low coverages, the molecule fully decomposes into atomic S and O. At large coverages, the formation of SO{sub 3} and SO{sub 4} takes place. The following sequence was found for the reactivity of the metals towards SO{sub 2}: Pt {approx} Rh < Ru < Mo << Zn, Sn, Cs. Alloying can be useful for reducing the chemical affinity of a metal for SO{sub 2} and controlling S poisoning. Pd atoms bonded to Rh and Pt atoms bonded to Sn interact weakly with SO{sub 2}. In general, SO{sub 2} mainly reacts with the O centers of metal oxides. SO{sub 4} is formed on CeO{sub 2} and SO{sub 3} on ZnO. On these systems there is no decomposition of SO{sub 2}. Dissociation of the molecule is observed after introducing a large amount of Ce{sup 3+} sites in ceria, or after depositing Cu or alkali metals on the oxide surfaces. These promote the catalytic activity of the oxides during the destruction of SO{sub 2}.

  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. Semiconductor nanowires DOI: 10.1002/smll.200500094

    E-Print Network [OSTI]

    Rogers, John A.

    of a semiconductor Si nanowire, synthesized via the VLS pro- cess, into metallic nickel silicide through parameters. Anisotropic growth of a metal onto a semiconductor nanowire (or a semicon- ductor on a metal approach to prepare metal/semiconductor nano- wire heterostructures by transforming specific sections

  7. 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...

  8. Anodic Aluminum Oxide Templated Channel Electrodes via Atomic Layer A. B. F. Martinsona,b

    E-Print Network [OSTI]

    60439, USA Dye-sensitized solar cells (DSSCs) utilize high surface area metal oxide sintered particle aluminum oxide membranes via atomic layer deposition. Introduction Dye sensitized solar cells (DSSCs) These photoelectrochemical cells use molecular dyes to sensitize high area, wide band gap semiconductor oxide photoanodes

  9. 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.

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

    SciTech Connect (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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Metal oxide/organic interface investigations for photovoltaic devices

    E-Print Network [OSTI]

    Pachoumi, Olympia

    2014-10-07T23:59:59.000Z

    summarises work I have carried out as a PhD student of the Optoelectronics Group at Cavendish Laboratory of the University of Cambridge since October 2010. I am thankful to the Engineering and Physical Sciences Research Council and the A.G. Leventis... are often used in many other optoelectronic devices such as photovoltaics and light emitting diodes. Sufficiently conducting oxides with the appropriate electron affinities and ionisation potentials, can be employed as charge transport and injection layers...

  18. 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.

  19. 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.

  20. Stabilization of Layered Metal Oxides | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion |Energy Usage » SearchEnergyDepartmentScopingOverview * Analyzer IDepartmentLayered Metal

  1. 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 Ricardo B. Metz Department of Chemistry, University of Massachusetts, Amherst, MA 01003 USA Abstract Gas such as methanol has attracted great experimental and theoretical interest due to its importance as an industrial

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

    E-Print Network [OSTI]

    Pennycook, Steve

    Surfactant Organic Molecules Restore Magnetism in Metal-Oxide Nanoparticle Surfaces Juan Salafranca, Nashville, Tennessee 37235, United States *S Supporting Information ABSTRACT: The properties of magnetic nanoparticles tend to be depressed by the unavoidable presence of a magnetically inactive surface layer. However

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

    E-Print Network [OSTI]

    Nair, Sankar

    Nanotube Formation: Researchers Learn To Control The Dimensions Of Metal Oxide Nanotubes ScienceDaily (Aug. 29, 2007) -- Moving beyond carbon nanotubes, researchers are developing insights-walled inorganic nanotubes could be useful in a range of nanotechnology applications that require precise control

  4. Understanding the NMR shifts in paramagnetic transition metal oxides using density functional theory calculations

    E-Print Network [OSTI]

    Ceder, Gerbrand

    obvious. In this paper, we show by means of density functional theory DFT calcula- tions that a rationalUnderstanding the NMR shifts in paramagnetic transition metal oxides using density functional functional theory DFT calculations in the generalized gradient approximation. For each compound, we calculate

  5. 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.

  6. Self-assembly of oxide-supported metal clusters into ring-like Kristoffer Meinander,

    E-Print Network [OSTI]

    Nordlund, Kai

    Self-assembly of oxide-supported metal clusters into ring-like structures Kristoffer Meinander, Kai, Finland Abstract Self-assembly is a phenomenon that continuously occurs at the nanoscale, as atoms form of these organized systems, but the precise mechanism, with which this self-assembly progresses, is seldom known

  7. 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.

  8. 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.

  9. 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

  10. 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

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

    E-Print Network [OSTI]

    Azad, Abdul-Majeed

    Evaluation 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 States § Department of Energy and Environment, Chalmers University of Technology, SE-412 96 Goteborg

  12. 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.

  13. 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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces andMapping theEnergy StorageAdvanced Materials Advanced Materials FindMetal

  14. Process for producing chalcogenide semiconductors

    DOE Patents [OSTI]

    Noufi, R.; Chen, Y.W.

    1985-04-30T23:59:59.000Z

    A process for producing chalcogenide semiconductor material is disclosed. The process includes forming a base metal layer and then contacting this layer with a solution having a low pH and containing ions from at least one chalcogen to chalcogenize the layer and form the chalcogenide semiconductor material.

  15. Method of making a catalytic metal oxide selective for the conversion of a gas and a coating system for the selective oxidation of hydrocarbons and carbon monoxide

    SciTech Connect (OSTI)

    Logothetis, E.M.; Soltis, R.E.

    1993-07-20T23:59:59.000Z

    A method is described of making a catalytic metal oxide selective to catalyzing the conversion of given gas species, comprising: intimately supporting a solid film of catalytic metal oxide on an electrically conducting material, said film having an exposed outer surface spaced no greater than 1,000 angstroms from said conducting material and said conducting material being matched to the composition of said oxide to change the electron state of the exposed outer surface to promote a reaction between given gas species and said oxide, said metal oxide being selected from the group consisting of TiO[sub 2], SnO[sub 2], FeO, SrTiO[sub 3], and CoO, and said conducting material being selected from the group consisting of Au, Pt, TiN, Pd, Rh, Ni, and Co.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. The steady-state thermal-hydraulic performance of 3500 MWth metal and oxide fueled LMRs

    SciTech Connect (OSTI)

    Vilim, R.B.; Hill, R.N.

    1989-03-01T23:59:59.000Z

    The thermal-hydraulic performance of a 3500 MWth metal and oxide fueled LMR is reported. Orifice zones are defined and coolant flowrates are given for use in safety analyses. The flux calculations were carried out in three-dimensional hexagonal-Z geometry using a finite differenced diffusion theory code. The heating calculations included the transport and deposition of gamma energy. The assembly temperature calculations were performed using a subchannel code.

  3. Surface Science Letters Bulk-defect dependent adsorption on a metal oxide surface

    E-Print Network [OSTI]

    Diebold, Ulrike

    -6028(01)01067-6 #12;Titanium dioxide is a wide-band gap semicon- ductor (Egap 3 eV) that can easily be reducedSurface Science Letters Bulk-defect dependent adsorption on a metal oxide surface: S/TiO2(1 1 0) E Abstract The adsorption of molecular sulfur on TiO2(1 1 0)(1 Ã? 1) has been studied with scanning tunneling

  4. The interactions between transition metal nanoparticles and their metal-oxide supports are often critical for heterogeneous metal nanoparticle

    E-Print Network [OSTI]

    Napp, Nils

    for selective hydrogenations (2, 3), oxidations (3­5), and the water-gas shift (WGS) reaction (3, 6). Several to saturation kinetics, with added water affecting the kinetics of the RDS. We explored potential mechanistic oxygen from the support (21, 27). Perhaps most importantly, as Fig. 1A shows, water dramatically

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

    SciTech Connect (OSTI)

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

    2013-07-31T23:59:59.000Z

    The ability to monitor gas species selectively, sensitively, and reliably in extreme temperatures and harsh conditions is critically important for more efficient energy production using conventional fossil energy based production technologies, enabling advanced technologies for fossil based power plants of the future, and improving efficiency in domestic manufacturing industries. Optical waveguide based sensing platforms have become increasingly important but a need exists for materials that exhibit useful changes in optical properties in response to changing gas atmospheres at high temperatures. In this manuscript, the onset of a near-IR absorption associated with an increase in free carrier density in doped metal oxide nanoparticles to form so-called conducting metal oxides is discussed in the context of results obtained for undoped and Al-doped ZnO nanoparticle based films. Detailed film characterization results are presented along with measured changes in optical absorption resulting from various high temperature treatments in a range of gas atmospheres. Optical property changes are also discussed in the context of a simple model for optical absorption in conducting metal oxide nanoparticles and thin films. The combination of experimental results and theoretical modeling presented here suggests that such materials have potential for high temperature optical gas sensing applications. Simulated sensing experiments were performed at 500 °C and a useful, rapid, and reproducible near-IR optical sensing response to H{sub 2} confirms that this class of materials shows great promise for optical gas sensing.

  6. Activation of Noble Metals on Metal-Carbide Surfaces: Novel Catalysts for CO Oxidation, Desulfurization and Hydrogenation Reactions

    SciTech Connect (OSTI)

    Rodriguez J. A.; Illas, F.

    2012-01-01T23:59:59.000Z

    This perspective article focuses on the physical and chemical properties of highly active catalysts for CO oxidation, desulfurization and hydrogenation reactions generated by depositing noble metals on metal-carbide surfaces. To rationalize structure-reactivity relationships for these novel catalysts, well-defined systems are required. High-resolution photoemission, scanning tunneling microscopy (STM) and first-principles periodic density-functional (DF) calculations have been used to study the interaction of metals of Groups 9, 10 and 11 with MC(001) (M = Ti, Zr, V, Mo) surfaces. DF calculations give adsorption energies that range from 2 eV (Cu, Ag, Au) to 6 eV (Co, Rh, Ir). STM images show that Au, Cu, Ni and Pt grow on the carbide substrates forming two-dimensional islands at very low coverage, and three-dimensional islands at medium and large coverages. In many systems, the results of DF calculations point to the preferential formation of admetal-C bonds with significant electronic perturbations in the admetal. TiC(001) and ZrC(001) transfer some electron density to the admetals facilitating bonding of the adatom with electron-acceptor molecules (CO, O{sub 2}, C{sub 2}H{sub 4}, SO{sub 2}, thiophene, etc.). For example, the Cu/TiC(001) and Au/TiC(001) systems are able to cleave both S-O bonds of SO{sub 2} at a temperature as low as 150 K, displaying a reactivity much larger than that of TiC(001) or extended surfaces of bulk copper and gold. At temperatures below 200 K, Au/TiC is able to dissociate O{sub 2} and perform the 2CO + O{sub 2} {yields} 2CO{sub 2} reaction. Furthermore, in spite of the very poor hydrodesulfurization performance of TiC(001) or Au(111), a Au/TiC(001) surface displays an activity for the hydrodesulfurization of thiophene higher than that of conventional Ni/MoS{sub x} catalysts. In general, the Au/TiC system is more chemically active than systems generated by depositing Au nanoparticles on oxide surfaces. Thus, metal carbides are excellent supports for enhancing the chemical reactivity of noble metals.

  7. 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.

  8. 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 ...

  9. CO Oxidation on Pt-Group Metals from Ultrahigh Vacuum to Near Atmospheric Pressures. 2. Palladium and Platinum

    E-Print Network [OSTI]

    Goodman, Wayne

    paper.1 Figure 1b shows the corresponding polarization modulation infrared reflection absorptionCO Oxidation on Pt-Group Metals from Ultrahigh Vacuum to Near Atmospheric Pressures. 2. Palladium

  10. 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].

  11. 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.

  12. Particle size effects of methylcyclopentane hydrogenolysis and SMSI in lanthanide oxide-supported 1%-platinum metal catalysts

    E-Print Network [OSTI]

    Terhune, Kyte Hamilton

    1985-01-01T23:59:59.000Z

    PARTICLE SIZE EFFECTS OF METHYLCYCLOPENTANE HYDROGENOLYSIS AND SMSI IN LANTHANIDE OXIDE-SUPPORTED 1%-PLATINUM METAL CATALYSTS A Thesis by KYTE HAMILTON TERHUNE Submitted to the Graduate College of Texas A&M University in partial fulfillment... of the requirement for the degree of MASTER OF SCIENCE May 1985 Major Subject: Chemistry PARTICLE SIZE EFFECTS OF METHYLCYCLOPENTANE HYDROGENOLYSIS AND SMSI IN LANTHANIDE OXIDE-SUPPORTED 1%-PLATINUM METAL CATALYSTS A Thesis by KYTE HAMILTON TERHUNE...

  13. 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}.

  14. 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.

  15. Modifications of the surface properties of metals by oxide overlayers: 1, Oxidized zirconium deposited on the Pt(100) single crystal surface

    SciTech Connect (OSTI)

    Bardi, U.; Ross, P.N.

    1986-06-01T23:59:59.000Z

    Metallic zirconium was deposited on a single crystal Pt(100) surface by thermal evaporation in UHV conditions. The deposit was oxidized by exposure to oxygen immediately after deposition. Oxidized zirconium was found to grow on the platinum ace by the layer-by-layer mechanism. The adsorption of carbon monoxide on the surface was studied as a function of the zirconium coverage. The results show that oxidized zirconium forms a chemically inert layer which blocks the adsorptive sites of the underlying platinum substrate. The properties of the free Pt surface were unaffected by the presence of the oxidized zirconium layer.

  16. Manganese Doping of Magnetic Iron Oxide Nanoparticles: Tailoring Surface Reactivity for a Regenerable Heavy Metal Sorbent

    SciTech Connect (OSTI)

    Warner, Cynthia L.; Chouyyok, Wilaiwan; Mackie, Katherine E.; Neiner, Doinita; Saraf, Laxmikant; Droubay, Timothy C.; Warner, Marvin G.; Addleman, Raymond S.

    2012-02-28T23:59:59.000Z

    A method for tuning the analyte affinity of magnetic, inorganic nanostructured sorbents for heavy metal contaminants is described. The manganese-doped iron oxide nanoparticle sorbents have a remarkably high affinity compared to the precursor material. Sorbent affinity can be tuned toward an analyte of interest simply by adjustment of the dopant quantity. The results show that following the Mn doping process there is a large increase in affinity and capacity for heavy metals (i.e., Co, Ni, Zn, As, Ag, Cd, Hg, and Tl). Capacity measurements were carried out for the removal of cadmium from river water and showed significantly higher loading than the relevant commercial sorbents tested for comparison. The reduction in Cd concentration from 100 ppb spiked river water to 1 ppb (less than the EPA drinking water limit of 5 ppb for Cd) was achieved following treatment with the Mn-doped iron oxide nanoparticles. The Mn-doped iron oxide nanoparticles were able to load 1 ppm of Cd followed by complete stripping and recovery of the Cd with a mild acid wash. The Cd loading and stripping is shown to be consistent through multiple cycles with no loss of sorbent performance.

  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. Electro-Ionics at metal oxide interfaces Hellsing (520720), Winkler, Wahnstrm, Olsson, Knee, Granath CURRICULUM VITAE Bo Hellsing (520720-3950)

    E-Print Network [OSTI]

    Hellsing, Bo

    Electro-Ionics at metal oxide interfaces Hellsing (520720), Winkler, Wahnström, Olsson, Knee: Electronic properties of Metal Quantum Wells and Varistor Materials" PhD: Asier Eiguren (2003), "Electron Chis (May 2006), "Electron and #12;Electro-Ionics at metal oxide interfaces Hellsing (520720), Winkler

  19. Study of microstructure and semiconductor to metallic conductivity transition in solid state sintered Li{sub 0.5}Mn{sub 0.5}Fe{sub 2}O{sub 4??} spinel ferrite

    SciTech Connect (OSTI)

    Bhowmik, R. N., E-mail: rnbhowmik.phy@pondiuni.edu.in; Vijayasri, G. [Department of Physics, Pondicherry University, R. Venkataraman Nagar, Kalapet, Puducherry-605 014 (India)

    2013-12-14T23:59:59.000Z

    Li{sub 0.5}Mn{sub 0.5}Fe{sub 2}O{sub 4} ferrite has been prepared by solid state sintering route. XRD pattern showed single phased cubic spinel structure. The samples exhibited typical character of plastoferrite with ring shaped surface microstructure. New feature observed in the present ferrite is the frequency activated conductivity transition from semiconductor to metallic state above 800?K. The increase of conductivity with frequency in the semiconducting regime follows Jonscher power law, while decrease of conductivity in metallic regime obeys Drude equation. The conductivity in semiconductor regime has been understood by hopping mechanism of localized charge carriers among the cations in B sites of cubic spinel structure. At higher temperatures, overlapping of electronic orbitals from neighbouring ions and free particle like motion of lighter Li{sup +} ions among interstitial lattices contributed metallic conductivity. The samples provided evidence of localized nature of the charge carriers at lower temperatures and increasing delocalized character with the increase of measurement temperature. From application point of view, such ferrites behave as semiconductor at low temperature and allow electromagnetic wave to pass through, but transform into a metallic reflector with negative dielectric constant at high temperature.

  20. 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.

  1. Strain induced electronic structure changes in magnetic transition metal oxides thin films

    SciTech Connect (OSTI)

    van der Laan, G.; Chopdekar, R.V.; Suzuki, Y.; Arenholz, E.

    2010-07-08T23:59:59.000Z

    We show that the angular dependence of x-ray magnetic circular dichroism (XMCD) is strongly sensitive to strain-induced electronic structure changes in magnetic transition metal oxides. We observe a pronounced dependence of the XMCD spectral shape on the experimental geometry as well as nonvanishing XMCD with distinct spectral features in transverse geometry in compressively strained MnCr{sub 2}O{sub 4} films. The angular dependent XMCD can be described as a sum over an isotropic and anisotropic contribution, the latter linearly proportional to the axial distortion due to strain. The XMCD spectra are well reproduced by atomic multiplet calculations.

  2. 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.

  3. REFORMULATION OF COAL-DERIVED TRANSPORTATION FUELS: SELECTIVE OXIDATION OF CARBON MONOXIDE ON METAL FOAM CATALYSTS

    SciTech Connect (OSTI)

    Paul Chin; Xiaolei Sun; George W. Roberts; Amornmart Sirijarhuphan; Sourabh Pansare; James G. Goodwin Jr; Richard W. Rice; James J. Spivey

    2005-06-01T23:59:59.000Z

    Hydrocarbon fuels must be reformed in a series of steps to provide hydrogen for use in proton exchange membrane fuel cells (PEMFCs). Preferential oxidation (PROX) is one method to reduce the CO concentration to less than 10 ppm in the presence of {approx}40% H{sub 2}, CO{sub 2}, and steam. This will prevent CO poisoning of the PEMFC anode. Structured supports, such as ceramic monoliths, can be used for the PROX reaction. Alternatively, metal foams offer a number of advantages over the traditional ceramic monolith.

  4. Synthesis of transition metal nitride by nitridation of metastable oxide precursor

    SciTech Connect (OSTI)

    Wang, Huamin; Wu, Zijie; Kong, Jing [Key Laboratory of Advanced Energy Materials Chemistry (MOE), College of Chemistry, Nankai University, Tianjin 300071 (China)] [Key Laboratory of Advanced Energy Materials Chemistry (MOE), College of Chemistry, Nankai University, Tianjin 300071 (China); Wang, Zhiqiang, E-mail: zqwang@mail.nankai.edu.cn [Key Laboratory of Advanced Energy Materials Chemistry (MOE), College of Chemistry, Nankai University, Tianjin 300071 (China) [Key Laboratory of Advanced Energy Materials Chemistry (MOE), College of Chemistry, Nankai University, Tianjin 300071 (China); Tianjin Key Laboratory of Water Environment and Resources, Tianjin Normal University, No. 393 Binshui Road, Xiqing Dist., Tianjin 300387 (China); Zhang, Minghui, E-mail: zhangmh@nankai.edu.cn [Key Laboratory of Advanced Energy Materials Chemistry (MOE), College of Chemistry, Nankai University, Tianjin 300071 (China)] [Key Laboratory of Advanced Energy Materials Chemistry (MOE), College of Chemistry, Nankai University, Tianjin 300071 (China)

    2012-10-15T23:59:59.000Z

    Metastable transition metal oxides were used as precursors to synthesize transition metal nitrides at low temperature. Amorphous MoO{sub 2} was prepared by reduction of (NH{sub 4}){sub 6}Mo{sub 7}O{sub 24} solution with hydrazine. As-synthesized amorphous MoO{sub 2} was transformed into fcc {gamma}-Mo{sub 2}N at 400 Degree-Sign C and then into hexagonal {delta}-MoN by further increasing the temperature to 600 Degree-Sign C under a NH{sub 3} flow. The nitridation temperature employed here is much lower than that employed in nitridation of crystalline materials, and the amorphous materials underwent a unique nitridation process. Besides this, the bimetallic nitride Ni{sub 2}Mo{sub 3}N was also synthesized by nitridating amorphous bimetallic precursor. These results suggested that the nitridation of amorphous precursor possessed potential to be a general method for synthesizing many interstitial metallic compounds, such as nitrides and carbides at low temperature. - graphical abstract: Amorphous oxide was used as new precursor to prepare nitride at low temperature. Pure {gamma}-Mo{sub 2}N and {delta}-MoN were obtained at 400 Degree-Sign C and at 600 Degree-Sign C, respectively. Highlights: Black-Right-Pointing-Pointer We bring out a new method to synthesize transition metal nitrides at low temperature. Black-Right-Pointing-Pointer Both mono- and bimetallic molybdenum nitrides were synthesized at a mild condition. Black-Right-Pointing-Pointer The formation of two different molybdenum nitrides {gamma}-Mo{sub 2}N and {delta}-MoN can be controlled from the same metastable precursor. Black-Right-Pointing-Pointer The nitridation temperature was much lower than that reported from crystalline precursors. Black-Right-Pointing-Pointer The metastable precursor had different reaction process in comparison with crystalline precursor.

  5. Variable temperature semiconductor film deposition

    DOE Patents [OSTI]

    Li, X.; Sheldon, P.

    1998-01-27T23:59:59.000Z

    A method of depositing a semiconductor material on a substrate is disclosed. The method sequentially comprises (a) providing the semiconductor material in a depositable state such as a vapor for deposition on the substrate; (b) depositing the semiconductor material on the substrate while heating the substrate to a first temperature sufficient to cause the semiconductor material to form a first film layer having a first grain size; (c) continually depositing the semiconductor material on the substrate while cooling the substrate to a second temperature sufficient to cause the semiconductor material to form a second film layer deposited on the first film layer and having a second grain size smaller than the first grain size; and (d) raising the substrate temperature, while either continuing or not continuing to deposit semiconductor material to form a third film layer, to thereby anneal the film layers into a single layer having favorable efficiency characteristics in photovoltaic applications. A preferred semiconductor material is cadmium telluride deposited on a glass/tin oxide substrate already having thereon a film layer of cadmium sulfide.

  6. 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

  7. Gate Metal-Induced Diffusion and Interface Reactions in Hf Oxide Films on Si

    SciTech Connect (OSTI)

    Goncharova, Lyudmila V.; Dalponte, Mateus; Celik, Ozgur; Garfunkel, Eric; Gustafsson, Torgny [Departments of Physics and Chemistry, and Laboratory for Surface Modification, Rutgers University, Piscataway, NJ 08854 (United States); Lysaght, Pat S.; Bersuker, Gennadi I. [Sematech, Austin, Texas 78741 (United States)

    2007-09-26T23:59:59.000Z

    When metal electrodes are deposited on a high-{kappa} metal-oxide/SiO{sub 2}/Si stack, chemical interactions may occur both at the metal/high-{kappa} and the high-{kappa}/Si interfaces, causing changes in electrical performance. We report here results from medium energy ion scattering (MEIS) and x-ray photoelectron (XPS) studies of oxygen and silicon transport and interfacial layer reactions in multilayer gate stacks. Our results show that Ti deposition on HfO{sub 2}/SiO{sub 2}/Si stacks causes reduction of the SiO{sub 2} interfacial layer and (to a lesser extent) the HfO{sub 2} layer. Silicon atoms initially present in the interfacial SiO{sub 2} layer incorporate into the bottom of the high-{kappa} layer. Some evidence for titanium-silicon interdiffusion through the high-{kappa} film in the presence of a titanium gate in crystalline HfO{sub 2} films is also reported.

  8. 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.

  9. 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.

  10. Wide band gap semiconductor templates

    DOE Patents [OSTI]

    Arendt, Paul N. (Los Alamos, NM); Stan, Liliana (Los Alamos, NM); Jia, Quanxi (Los Alamos, NM); DePaula, Raymond F. (Santa Fe, NM); Usov, Igor O. (Los Alamos, NM)

    2010-12-14T23:59:59.000Z

    The present invention relates to a thin film structure based on an epitaxial (111)-oriented rare earth-Group IVB oxide on the cubic (001) MgO terminated surface and the ion-beam-assisted deposition ("IBAD") techniques that are amendable to be over coated by semiconductors with hexagonal crystal structures. The IBAD magnesium oxide ("MgO") technology, in conjunction with certain template materials, is used to fabricate the desired thin film array. Similarly, IBAD MgO with appropriate template layers can be used for semiconductors with cubic type crystal structures.

  11. Use of high-temperature gas-tight electrochemical cells to measure electronic transport and thermodynamics in metal oxides

    SciTech Connect (OSTI)

    Park, J.H.; Ma, B.; Park, E.T. [Argonne National Lab., IL (United States). Energy Technology Div.

    1997-10-01T23:59:59.000Z

    By using a gas-tight electrochemical cell, the authors can perform high-temperature coulometric titration and measure electronic transport properties to determine the electronic defect structure of metal oxides. This technique reduces the time and expense required for conventional thermogravimetric measurements. The components of the gas-tight coulometric titration cell are an oxygen sensor, Pt/yttria stabilized zirconia (YSZ)/Pt, and an encapsulated metal oxide sample. Based on cell design, both transport and thermodynamic measurements can be performed over a wide range of oxygen partial pressures (pO{sub 2} = 10{sup {minus}35} to 1 atm). This paper describes the high-temperature gas-tight electrochemical cells used to determine electronic defect structures and transport properties for pure and doped-oxide systems, such as YSZ, doped and pure ceria (Ca-CeO{sub 2} and CeO{sub 2}), copper oxides, and copper-oxide-based ceramic superconductors, transition metal oxides, SrFeCo{sub 0.5}O{sub x}, and BaTiO{sub 3}.

  12. 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.

  13. A hybrid magnetic/complementary metal oxide semiconductor three-context memory bit cell for non-volatile circuit design

    SciTech Connect (OSTI)

    Jovanovi?, B., E-mail: bojan.jovanovic@lirmm.fr, E-mail: lionel.torres@lirmm.fr; Brum, R. M.; Torres, L. [LIRMM—University of Montpellier 2/UMR CNRS 5506, 161 Rue Ada, 34095 Montpellier (France)

    2014-04-07T23:59:59.000Z

    After decades of continued scaling to the beat of Moore's law, it now appears that conventional silicon based devices are approaching their physical limits. In today's deep-submicron nodes, a number of short-channel and quantum effects are emerging that affect the manufacturing process, as well as, the functionality of the microelectronic systems-on-chip. Spintronics devices that exploit both the intrinsic spin of the electron and its associated magnetic moment, in addition to its fundamental electronic charge, are promising solutions to circumvent these scaling threats. Being compatible with the CMOS technology, such devices offer a promising synergy of radiation immunity, infinite endurance, non-volatility, increased density, etc. In this paper, we present a hybrid (magnetic/CMOS) cell that is able to store and process data both electrically and magnetically. The cell is based on perpendicular spin-transfer torque magnetic tunnel junctions (STT-MTJs) and is suitable for use in magnetic random access memories and reprogrammable computing (non-volatile registers, processor cache memories, magnetic field-programmable gate arrays, etc). To demonstrate the potential our hybrid cell, we physically implemented a small hybrid memory block using 45?nm × 45?nm round MTJs for the magnetic part and 28?nm fully depleted silicon on insulator (FD-SOI) technology for the CMOS part. We also report the cells measured performances in terms of area, robustness, read/write speed and energy consumption.

  14. Performance analysis of boron nitride embedded armchair graphene nanoribbon metal–oxide–semiconductor field effect transistor with Stone Wales defects

    SciTech Connect (OSTI)

    Chanana, Anuja; Sengupta, Amretashis; Mahapatra, Santanu [Nano Scale Device Research Laboratory, Department of Electronic Systems Engineering, Indian Institute of Science, Bangalore 560 012 (India)

    2014-01-21T23:59:59.000Z

    We study the performance of a hybrid Graphene-Boron Nitride armchair nanoribbon (a-GNR-BN) n-MOSFET at its ballistic transport limit. We consider three geometric configurations 3p, 3p + 1, and 3p + 2 of a-GNR-BN with BN atoms embedded on either side (2, 4, and 6 BN) on the GNR. Material properties like band gap, effective mass, and density of states of these H-passivated structures are evaluated using the Density Functional Theory. Using these material parameters, self-consistent Poisson-Schrodinger simulations are carried out under the Non Equilibrium Green's Function formalism to calculate the ballistic n-MOSFET device characteristics. For a hybrid nanoribbon of width ?5?nm, the simulated ON current is found to be in the range of 265??A–280??A with an ON/OFF ratio 7.1 × 10{sup 6}–7.4 × 10{sup 6} for a V{sub DD}?=?0.68?V corresponding to 10?nm technology node. We further study the impact of randomly distributed Stone Wales (SW) defects in these hybrid structures and only 2.5% degradation of ON current is observed for SW defect density of 3.18%.

  15. Characterization of near-terahertz complementary metal-oxide semiconductor circuits using a Fourier-transform interferometer

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

    Arenas, D. J. [Univ. of North Florida, Jacksonville, FL (United States); Shim, Dongha [Univ. of Florida, Gainesville, FL (United States); Koukis, D. I. [Univ. of Florida, Gainesville, FL (United States); Seok, Eunyoung [Univ. of Florida, Gainesville, FL and Texas Instruments, Dallas, TX (United States); Tanner, D. B. [Univ. of Florida, Gainesville, FL (United States); O, Kenneth K. [Univ. of Texas, Dallas, TX (United States)

    2011-10-24T23:59:59.000Z

    Optical methods for measuring of the emission spectra of oscillator circuits operating in the 400–600 GHz range are described. The emitted power from patch antennas included in the circuits is measured by placing the circuit in the source chamber of a Fourier-transform interferometric spectrometer. The results show that this optical technique is useful for measuring circuits pushing the frontier in operating frequency. The technique also allows the characterization of the circuit by measuring the power radiated in the fundamental and in the harmonics. This capability is useful for oscillator architectures designed to cancel the fundamental and use higher harmonics. The radiated power was measured using two techniques: direct measurement of the power by placing the device in front of a bolometer of known responsivity, and by comparison to the estimated power from blackbody sources. The latter technique showed that these circuits have higher emission than blackbody sources at the operating frequencies, and, therefore, offer potential spectroscopy applications.

  16. 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.

  17. Spectroscopic Studies of O-Vacancy Defects in Transition Metal Oxides

    SciTech Connect (OSTI)

    Lucovsky, G.; Luning, J.; Fleming, L.B.; Ulrich, M.D.; Rowe, J.E.; Seo, H.; Lee, S.; Lysaght, P.; Bersuker, G.

    2009-06-03T23:59:59.000Z

    Dielectrics comprised of nano-crystalline HfO{sub 2} in gate stacks with thin SiO{sub 2}/SiON interfacial transition regions display significant asymmetries with respect to trapping of Si substrate injected holes and electrons. Based on spectroscopic studies, and guided by ab initio theory, electron and hole traps in HfO{sub 2} and other transition metal elemental oxides are assigned to O-atom divacancies clustered at internal grain boundaries of nano-crystalline films. Engineering solutions in which grain boundary defects are suppressed include: (i) ultra-thin, <2 nm, HfO{sub 2} fims, (ii) chemically phase separated high HfO2 content silicate films, and (iii) non-crystalline Zr/Hf Si oxynitride films.

  18. Method for producing metal oxide aerogels having densities less than 0.02 g/cc

    SciTech Connect (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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

    Methane 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 a MoO3/HZSM-5 catalyst stimulated us to examine methane activation by the transition-metal oxide

  3. Corrosion and Protection of Metallic Interconnects in Solid Oxide Fuel Cells

    SciTech Connect (OSTI)

    Yang, Z Gary; Stevenson, Jeffry W.; Singh, Prabhakar

    2007-12-09T23:59:59.000Z

    Energy security and increased concern over environmental protection have spurred a dramatic world-wide growth in research and development of fuel cells, which electrochemically convert incoming fuel into electricity with no or low pollution. Fuel cell technology has become increasingly attractive to a number of sectors, including utility, automotive, and defense industries. Among the various types of fuel cells, solid oxide fuel cells (SOFCs) operate at high temperature (typically 650-1,000 C) and have advantages in terms of high conversion efficiency and the flexibility of using hydrocarbon fuels, in addition to hydrogen. The high temperature operation, however, can lead to increased mass transport and interactions between the surrounding environment and components that are required to be stable during a lifetime of thousands of hours and up to hundreds of thermal cycles. For stacks with relatively low operating temperatures (<800 C), the interconnects that are used to electrically connect a number of cells in series are typically made from cost-effective metals or alloys. The metallic interconnects must demonstrate excellent stability in a very challenging environment during SOFC operation, as they are simultaneously exposed to both an oxidizing (air) environment on the cathode side and a reducing environment (hydrogen or a reformed hydrocarbon fuel) on the anode side. Other challenges include the fact that water vapor is likely to be present in both of these environments, and the fuel is likely to contain impurities, such as sulfides. Since the fuel is usually a reformed hydrocarbon fuel, such as natural gas, coal gas, biogas, gasoline, etc., the interconnect is exposed to a wet carbonaceous environment at the anode side. Finally, the interconnect must be stable towards any adjacent components, such as electrodes, seals and electrical contact materials, with which it is in physical contact.

  4. 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.

  5. High-temperature corrosion of metallic alloys in an oxidizing atmosphere containing NaCl

    SciTech Connect (OSTI)

    Federer, J.I.

    1989-02-01T23:59:59.000Z

    A particular heat-exchanger application involved metallic alloys exposed to flue gases of an aluminum remelt furnace. Because the flue gases might contain NaCl and other halides, the corrosion behavior of the alloys was to be investigated. Planned direct exposure of candidate alloys to the flue gases, however, was not conducted because of premature termination of the project. Complementary laboratory testing was conducted on seven commercially available alloys and two nickel aluminides. These materials were exposed to an oxidizing atmosphere containing 0.06 wt % NaCl for 1100 h at 1000/degree/C. Most of the alloy exhibited grain-boundary attack, which resulted in complete oxidation of enveloped grains. The alloys Incoloy MA-956, Incoloy 800, Inconel 625, Inconel 601, Hastelloy X, Haynes 188, and nickel aluminide IC-50 were substantially more corroded than Alloy 214 and nickel aluminide IC-221. The latter two alloys, therefore, would probably be superior to the others in application involving flue gases containing NaCl. Strength fabricability, and weldability, which are briefly discussed, would also affect selection of materials. 8 refs., 12 figs., 5 tabs.

  6. Metal-gate-induced reduction of the interfacial layer in Hf oxide gate stacks

    SciTech Connect (OSTI)

    Goncharova, L. V.; Dalponte, M.; Gustafsson, T.; Celik, O.; Garfunkel, E.; Lysaght, P. S.; Bersuker, G. [Department of Physics and Astronomy, and Laboratory for Surface Modification, Rutgers University, 136 Frelinghuysen Rd., Piscataway, New Jersey 08854 (United States); Department of Chemistry and Chemical Biology, and Laboratory for Surface Modification, Rutgers University, 610 Taylor Rd., Piscataway, New Jersey 08854 (United States); SEMATECH, 2705 Montopolis Dr., Austin, Texas 78741 (United States)

    2007-03-15T23:59:59.000Z

    The properties of high-{kappa} metal oxide gate stacks are often determined in the final processing steps following dielectric deposition. We report here results from medium energy ion scattering and x-ray photoelectron spectroscopy studies of oxygen and silicon diffusion and interfacial layer reactions in multilayer gate stacks. Our results show that Ti metallization of HfO{sub 2}/SiO{sub 2}/Si stacks reduces the SiO{sub 2} interlayer and (to a more limited extent) the HfO{sub 2} layer. We find that Si atoms initially present in the interfacial SiO{sub 2} layer incorporate into the bottom of the high-{kappa} layer. Some evidence for Ti-Si interdiffusion through the high-{kappa} film in the presence of a Ti gate in the crystalline HfO{sub 2} films is also reported. This diffusion is likely to be related to defects in crystalline HfO{sub 2} films, such as grain boundaries. High-resolution transmission electron microscopy and corresponding electron energy loss spectroscopy scans show aggressive Ti-Si intermixing and oxygen diffusion to the outermost Ti layer, given high enough annealing temperature. Thermodynamic calculations show that the driving forces exist for some of the observed diffusion processes.

  7. 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.

  8. INFLUENCE OF OXIDE GROWTH AND METAL CREEP ON STRAIN DEVELOPMENT IN THE STEAM-SIDE OXIDE IN BOILER TUBES

    SciTech Connect (OSTI)

    Sabau, Adrian S [ORNL; Wright, Ian G [ORNL

    2010-01-01T23:59:59.000Z

    This effort is concerned with developing a quantitative description of the exfoliation behavior of oxide scales grown inside steam tubes in a pressure boiler. Consideration of the development of stress/strain in growing oxides has included expansion mismatch-induced strains during thermal cycling as well as inelastic mechanical effects from oxide/alloy creep phenomena and volume change from oxide growth. The magnitude of the parameters used has been closely matched to actual boiler operating practice. The creep model used was validated against published data. Representation of oxide growth-induced strain was found to be a difficult challenge because the processes involved are not fully understood. In addition to the traditional uniaxial (radial) and dilatational models, lateral growth models are discussed in the context of experimentally-derived criteria, such as the level of elastic strains involved in oxide exfoliation. It was found that strain variation in the oxide cannot be neglected.

  9. 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.

  10. Semiconductor heterojunction band offsets and charge neutrality

    E-Print Network [OSTI]

    Lee, Chomsik

    2012-06-07T23:59:59.000Z

    involving lasers, light emitting diodes, and metal-semiconductor field effect transistors, the models of Schottky and Bardeen correspond only to limiting cases, in which the energy barriers for electrons at the interface respectively vary linearly... of metal-lead sulfide contacts on the polarity of the applied voltage. In the 1930's, Tamm, Mott, Schottky and others developed the basic theory related to surface and interface semiconductor properties. Schottky introduced the first modern model Journal...

  11. HAPPY NEW YEAR! Semiconductor Spintronics

    E-Print Network [OSTI]

    Nikolic, Branislav K.

    Semiconductors MnGa S=5/2 moment Mn++ plus hole 200 unit cells Yakunin et al. PRL 96 216806 (2004) #12;Atomic Insulating Metallic Carrier-mediated Long-range Order Ohno, Munekata et al. PRL '89 PRL '92 APL `96 Mechanism;Theory of Spin Hamiltonian Konig et al. PRL (2000), PRB (2002) #12;Envelope Function Theory Light Holes

  12. Wafer-fused semiconductor radiation detector

    DOE Patents [OSTI]

    Lee, Edwin Y. (Livermore, CA); James, Ralph B. (Livermore, CA)

    2002-01-01T23:59:59.000Z

    Wafer-fused semiconductor radiation detector useful for gamma-ray and x-ray spectrometers and imaging systems. The detector is fabricated using wafer fusion to insert an electrically conductive grid, typically comprising a metal, between two solid semiconductor pieces, one having a cathode (negative electrode) and the other having an anode (positive electrode). The wafer fused semiconductor radiation detector functions like the commonly used Frisch grid radiation detector, in which an electrically conductive grid is inserted in high vacuum between the cathode and the anode. The wafer-fused semiconductor radiation detector can be fabricated using the same or two different semiconductor materials of different sizes and of the same or different thicknesses; and it may utilize a wide range of metals, or other electrically conducting materials, to form the grid, to optimize the detector performance, without being constrained by structural dissimilarity of the individual parts. The wafer-fused detector is basically formed, for example, by etching spaced grooves across one end of one of two pieces of semiconductor materials, partially filling the grooves with a selected electrical conductor which forms a grid electrode, and then fusing the grooved end of the one semiconductor piece to an end of the other semiconductor piece with a cathode and an anode being formed on opposite ends of the semiconductor pieces.

  13. Semiconductor switch geometry with electric field shaping

    DOE Patents [OSTI]

    Booth, Rex (Livermore, CA); Pocha, Michael D. (Livermore, CA)

    1994-01-01T23:59:59.000Z

    An optoelectric switch is disclosed that utilizes a cylindrically shaped and contoured GaAs medium or other optically active semiconductor medium to couple two cylindrically shaped metal conductors with flat and flared termination points each having an ovoid prominence centrally extending there from. Coupling the truncated ovoid prominence of each conductor with the cylindrically shaped optically active semiconductor causes the semiconductor to cylindrically taper to a triple junction circular line at the base of each prominence where the metal conductor conjoins with the semiconductor and a third medium such as epoxy or air. Tapering the semiconductor at the triple junction inhibits carrier formation and injection at the triple junction and thereby enables greater current carrying capacity through and greater sensitivity of the bulk area of the optically active medium.

  14. Semiconductor switch geometry with electric field shaping

    DOE Patents [OSTI]

    Booth, R.; Pocha, M.D.

    1994-08-23T23:59:59.000Z

    An optoelectric switch is disclosed that utilizes a cylindrically shaped and contoured GaAs medium or other optically active semiconductor medium to couple two cylindrically shaped metal conductors with flat and flared termination points each having an ovoid prominence centrally extending there from. Coupling the truncated ovoid prominence of each conductor with the cylindrically shaped optically active semiconductor causes the semiconductor to cylindrically taper to a triple junction circular line at the base of each prominence where the metal conductor conjoins with the semiconductor and a third medium such as epoxy or air. Tapering the semiconductor at the triple junction inhibits carrier formation and injection at the triple junction and thereby enables greater current carrying capacity through and greater sensitivity of the bulk area of the optically active medium. 10 figs.

  15. MICROSTRUCTURE-PROPERTY RELATIONSHIPS OF A ZINC OXIDE VARISTOR MATERIAL

    E-Print Network [OSTI]

    Williama, Pamela Louise

    2011-01-01T23:59:59.000Z

    RELATIONSHIPS OF A ZINC OXIDE VARISTOR MATERIAL Pamelaresistors, and zinc oxide varistors are semiconductorRELATIONSHIPS OF A ZINC OXIDE VARISTOR MATERIAL CONTENTS

  16. DOI: 10.1002/adma.200601787 Microsolidics: Fabrication of Three-Dimensional Metallic

    E-Print Network [OSTI]

    Prentiss, Mara

    .[18] The technique has also been used to form 3D connec- tions (e.g., bridging opposite sides approaches to bridge electrical "islands" of metal by heating solid rods of solder "on chip"--the solder oxide semiconductor field-effect transistors,[26] and flexible gold­polymer nano- composites as passive

  17. Template-Based Growth of Various Oxide Nanorods by SolGel Electrophoresis**

    E-Print Network [OSTI]

    Cao, Guozhong

    catalytic growth, LAC) has been used to form nano- rods of compound semiconductors.[4] A third example for nanostructures such as rods, wires, and hollow tubules is the template-based synthesis technique. In this method, including metal and polymer nano- rods,[2,7±9] oxide nanorods,[2,7,10,11] and composite nanostruc- tures.[2

  18. Ultrathin amorphous zinc-tin-oxide buffer layer for enhancing heterojunction interface quality in

    E-Print Network [OSTI]

    -abundant, non-toxic, and air-stable materials represent a promising class of photovoltaic (PV) devices for cost-effective manufacturing. Earth- abundant metal-oxide semiconductors comprise an attractive set of materials for photovoltaic applications, given their auspicious optoelec- tronic properties and chemical

  19. 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. ...

  20. Oxidation of Metals, Vol. 61, Nos. 3/4, April 2004 ( 2004) Thermal Conductivity, Phase Stability, and Oxidation

    E-Print Network [OSTI]

    Trice, Rodney W.

    , and Oxidation Resistance of Y3Al5O12 (YAG)/Y2O3­ZrO2 (YSZ) Thermal-Barrier Coatings Y. J. Su, R. W. Trice,# K oxidation resistance while maintaining low thermal conductivity and good phase stability. Padture) is proposed. The objective of this work is to quantify the effect of YAG on thermal resistance, long

  1. Safety and core design of large liquid-metal cooled fast breeder reactors

    E-Print Network [OSTI]

    Qvist, Staffan Alexander

    2013-01-01T23:59:59.000Z

    Absorption Metal (Zr) Metal (Mo) Carbide Nitride Oxidef /? a k ? Metal (Zr) Metal (Mo) Carbide Nitride Oxide Table? a k ? Metal (Zr) Metal (Mo) Carbide Nitride Oxide CHAPTER

  2. 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

  3. Ferromagnetism in Oxide Semiconductors . | EMSL

    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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsing ZirconiaPolicyFeasibility ofSmall15.000TechnologyTune ITFerrin| EMSL

  4. 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...

  5. 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.

  6. 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.

  7. Degradation of solid oxide fuel cell metallic interconnects in fuels containing sulfur

    SciTech Connect (OSTI)

    Ziomek-Moroz, M.; Hawk, Jeffrey A.

    2005-01-01T23:59:59.000Z

    Hydrogen is the main fuel for all types of fuel cells except direct methanol fuel cells. Hydrogen can be generated from all manner of fossil fuels, including coal, natural gas, diesel, gasoline, other hydrocarbons, and oxygenates (e.g., methanol, ethanol, butanol, etc.). Impurities in the fuel can cause significant performance problems and sulfur, in particular, can decrease the cell performance of fuel cells, including solid oxide fuel cells (SOFC). In the SOFC, the high (800-1000°C) operating temperature yields advantages (e.g., internal fuel reforming) and disadvantages (e.g., material selection and degradation problems). Significant progress in reducing the operating temperature of the SOFC from ~1000 ºC to ~750 ºC may allow less expensive metallic materials to be used for interconnects and as balance of plant (BOP) materials. This paper provides insight on the material performance of nickel, ferritic steels, and nickel-based alloys in fuels containing sulfur, primarily in the form of H2S, and seeks to quantify the extent of possible degradation due to sulfur in the gas stream.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Waste minimization in semiconductor processing

    SciTech Connect (OSTI)

    Hardwick, S.J.; Mailloux, J.C. [Novapure Corp., Danbury, CT (United States)

    1994-12-31T23:59:59.000Z

    The US semiconductor industry uses 5--7 thousand pounds of arsine annually. Fifty to eighty percent of the arsine used becomes a waste product, which requires abatement. Traditional methods of abatement are reviewed with an emphasis on dry chemical scrubbing. A variety of dry chemical scrubbing materials were evaluated for arsine capacity, using activated carbon as the baseline for comparison. Of the available technologies, dry chemical scrubbing is the most effective means of minimizing arsenic containing waste generated from semiconductor effluents. A copper oxide based media has been identified which has high capacity, high efficiency and treats the spectrum of gases used in MOCVD processes. Reclaim and recovery of spent scrubber media has the potential to drastically reduce arsenic waste from semiconductor manufacturing.

  13. 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...

  14. 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

  15. 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.

  16. 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.

  17. Fabrication of Metal/Oxide Nanostructures by Anodization Processes for Biosensor, Drug Delivery and Supercapacitor Applications

    E-Print Network [OSTI]

    Chen, Po-Chun

    2014-01-13T23:59:59.000Z

    applications of micro/nano structures; (2) novel processes to innovate anodic aluminum oxide nanotube template; (3) the supercapacitor applications of anodic titanium oxide. First, the extremely high surface area AAO coated microneedle and microneedle array...

  18. In situ examination of tin oxide atomic layer deposition using quartz crystal microbalance and Fourier transform infrared techniques

    E-Print Network [OSTI]

    George, Steven M.

    -type semiconductor metal oxide that has many applications in various fields due to its special optical, electrical capacity anode for next gen- eration lithium ion batteries.3,4 SnO2 can also be used as a catalyst typically around 10-2 cm. The adsorp- tion of O2 from air removes the electron charge carriers from

  19. Operation of mixed conducting metal oxide membrane systems under transient conditions

    DOE Patents [OSTI]

    Carolan, Michael Francis (Allentown, PA)

    2008-12-23T23:59:59.000Z

    Method of operating an oxygen-permeable mixed conducting membrane having an oxidant feed side, an oxidant feed surface, a permeate side, and a permeate surface, which method comprises controlling the differential strain between the permeate surface and the oxidant feed surface at a value below a selected maximum value by varying the oxygen partial pressure on either or both of the oxidant feed side and the permeate side of the membrane.

  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

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

  1. 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...

  2. Low Temperature Deposition of Metal Oxide Thin Films in Supercritical Carbon Dioxide using Metal-organic Precursors

    E-Print Network [OSTI]

    Gougousi, Theodosia

    and are driven by the energy provided by a heated substrate. Both these vacuum-based techniques require in the precursor adsorption, oxidation and by-product desorption. [5] Use of solvation energy may provide a viable. Pressurized CO2 was delivered using an ISCO 260D syringe pump through a high- pressure manifold. Resistive

  3. 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.

  4. 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

    oxidation Polarization modulation Infrared reflection absorption spectroscopy Reaction kinetics a b s t rCO oxidation trends on Pt-group metals from ultrahigh vacuum to near atmospheric pressures3 Torr) and near atmospheric (1­102 Torr) pressures in a batch reactor under steady-state conditions

  5. Synthesis of Mixed Metal Oxides for Hydrodeoxygenation of Pyrolysis Oil for Alternative Fuels Sarah McNew, Tiorra Ross and Carsten Sievers

    E-Print Network [OSTI]

    Das, Suman

    · Flash pyrolysis on biomass [1] · Short residence times and flexible feed · Bio-oils produced are close to dissociate hydrogen Goal: synthesize metal free, sulfur free, catalysts for HDO Biomass Pyrolysis OilSynthesis of Mixed Metal Oxides for Hydrodeoxygenation of Pyrolysis Oil for Alternative Fuels Sarah

  6. On the origin of the two-dimensional electron gas at AlGaN/GaN heterojunctions and its influence on recessed-gate metal-insulator-semiconductor high electron mobility transistors

    SciTech Connect (OSTI)

    Bakeroot, B., E-mail: Benoit.Bakeroot@elis.ugent.be [Centre for Microsystems Technology (CMST), imec and Ghent University, Technologiepark 914a, 9052 Gent (Belgium); You, S.; Van Hove, M.; De Jaeger, B.; Geens, K.; Stoffels, S.; Decoutere, S. [imec, Kapeldreef 75, 3001 Leuven (Belgium); Wu, T.-L.; Hu, J. [imec, Kapeldreef 75, 3001 Leuven (Belgium); Department of Electrical Engineering, KU Leuven, 3001 Leuven (Belgium)

    2014-10-07T23:59:59.000Z

    It is commonly accepted that interface states at the passivation surface of AlGaN/GaN heterostructures play an important role in the formation of the 2DEG density. Several interface state models are cited throughout literature, some with discrete levels, others with different kinds of distributions, or a combination of both. The purpose of this article is to compare the existing interface state models with both direct and indirect measurements of these interface states from literature (e.g., through the hysteresis of transfer characteristics of Metal-Insulator-Semiconductor High Electron Mobility Transistors (MISHEMTs) employing such an interface in the gate region) and Technology Computer Aided Design (TCAD) simulations of 2DEG densities as a function of the AlGaN thickness. The discrepancies between those measurements and TCAD simulations (also those commonly found in literature) are discussed. Then, an alternative model inspired by the Disorder Induced Gap State model for compound semiconductors is proposed. It is shown that defining a deep border trap inside the insulator can solve these discrepancies and that this alternative model can explain the origin of the two dimensional electron gas in combination with a high-quality interface that, by definition, has a low interface state density.

  7. Control of differential strain during heating and cooling of mixed conducting metal oxide membranes

    DOE Patents [OSTI]

    Carolan, Michael Francis (Allentown, PA)

    2007-12-25T23:59:59.000Z

    Method of operating an oxygen-permeable mixed conducting membrane having an oxidant feed side and a permeate side, which method comprises controlling the differential strain between the oxidant feed side and the permeate side by varying either or both of the oxygen partial pressure and the total gas pressure on either or both of the oxidant feed side and the permeate side of the membrane while changing the temperature of the membrane from a first temperature to a second temperature.

  8. X-ray absorption spectroscopy study of the local structure of heavy metal ions incorporated into electrodeposited nickel oxide films

    SciTech Connect (OSTI)

    Balasubramanian, M.; Melendres, C.A. [Argonne National Lab., IL (United States). Chemical Technology Div.] [Argonne National Lab., IL (United States). Chemical Technology Div.; Mansour, A.N. [Naval Surface Warfare Center, Bethesda, MD (United States). Carderock Div.] [Naval Surface Warfare Center, Bethesda, MD (United States). Carderock Div.

    1999-02-01T23:59:59.000Z

    The incorporation of heavy metal ions into simulated corrosion films has been investigated using spectroscopic and electrochemical techniques. The films were formed by electrodeposition of the appropriate oxide (hydroxide) onto a graphite substrate. Synchrotron X-ray absorption spectroscopy (XAS) was used to determine the structure and composition of the host oxide film, as well as the local structure of the impurity ion. Results on the incorporation of Ce and Sr into surface films of Ni(OH){sub 2} and NiOOH are reported. Cathodically deposited Ni(OH){sub 2} was found to be mainly in the alpha form while anodically prepared NiOOH showed the presence of Ni{sup +2} and Ni{sup +4}. Cerium incorporated into Ni(OH){sub 2} exists as mixed Ce{sup +3} and Ce{sup +4} phases; a Ce{sup +4} species was found when Ce was codeposited with NiOOH. The structure of the Ce{sup +4} phase in anodic films appears similar to a Ce(OH){sub 4} standard. However, XAS, X-ray diffraction, and laser Raman measurements indicate that the latter chemical formulation is probably incorrect and that the material is really a disordered form of hydrous cerium oxide. The local structure of this material is similar to CeO{sub 2} but has much higher structural disorder. The significance of this finding on the question of the structure of Ce-based corrosion inhibitors in aluminum oxide films is pointed out. Moreover, the authors found it possible to form pure Ce oxide (hydroxide) films on graphite by both cathodic and anodic electrodeposition; their structures have also been elucidated. Strontium incorporated into nickel oxide films consists of Sr{sup +2} which is coordinated to oxygen atoms and is likely to exist as small domains of coprecipitated material.

  9. Method for forming metal contacts

    DOE Patents [OSTI]

    Reddington, Erik; Sutter, Thomas C; Bu, Lujia; Cannon, Alexandra; Habas, Susan E; Curtis, Calvin J; Miedaner, Alexander; Ginley, David S; Van Hest, Marinus Franciscus Antonius Maria

    2013-09-17T23:59:59.000Z

    Methods of forming metal contacts with metal inks in the manufacture of photovoltaic devices are disclosed. The metal inks are selectively deposited on semiconductor coatings by inkjet and aerosol apparatus. The composite is heated to selective temperatures where the metal inks burn through the coating to form an electrical contact with the semiconductor. Metal layers are then deposited on the electrical contacts by light induced or light assisted plating.

  10. Experimental Study of Electron Transport through Nanometer-Scale Metal-Oxide Junctions

    E-Print Network [OSTI]

    -annealing. The resistive bistability effect has been observed for all these materials, with particularly high switching, crested barrier, rapid thermal annealing, endurance, resistive bistability, reproducibility. #12;v List properties of Nb/Al/Nb junctions fabricated using thermal oxidation or rf-plasma oxidation at various

  11. (Data in thousand metric tons of silicon content unless otherwise noted) Domestic Production and Use: Estimated value of silicon metal and alloys (excluding semiconductor-grade silicon)

    E-Print Network [OSTI]

    %; China, 16%; South Africa, 13%; Canada, 12%; and other, 39%. Tariff: Item Number Normal Trade Relations metal: Brazil, 37%; South Africa, 25%; Canada, 14%; Norway, 6%; and other, 18%. Total: Brazil, 20 energy costs. Demand for silicon metal comes primarily from the aluminum and chemical industries

  12. Graded core/shell semiconductor nanorods and nanorod barcodes

    DOE Patents [OSTI]

    Alivisatos, A. Paul; Scher, Erik C.; Manna, Liberato

    2013-03-26T23:59:59.000Z

    Graded core/shell semiconductor nanorods and shapped nanorods are disclosed comprising Group II-VI, Group III-V and Group IV semiconductors and methods of making the same. Also disclosed are nanorod barcodes using core/shell nanorods where the core is a semiconductor or metal material, and with or without a shell. Methods of labeling analytes using the nanorod barcodes are also disclosed.

  13. Graded core/shell semiconductor nanorods and nanorod barcodes

    DOE Patents [OSTI]

    Alivisatos, A. Paul (Oakland, CA); Scher, Erik C. (San Francisco, CA); Manna, Liberato (Lecce, IT)

    2010-12-14T23:59:59.000Z

    Graded core/shell semiconductor nanorods and shaped nanorods are disclosed comprising Group II-VI, Group III-V and Group IV semiconductors and methods of making the same. Also disclosed are nanorod barcodes using core/shell nanorods where the core is a semiconductor or metal material, and with or without a shell. Methods of labeling analytes using the nanorod barcodes are also disclosed.

  14. Life Prediction of Coated and Uncoated Metallic Interconnect for Solid Oxide Fuel Cell Applications

    SciTech Connect (OSTI)

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

    2009-04-15T23:59:59.000Z

    Oxidation reaction of the ferritic stainless interconnects in a typical SOFC working environment is unavoidable and the thickness of the oxide scale will continue to grow with operating time, even with protective coatings. The interfacial strength of the various interfaces for the uncoated and coated ferritic interconnects is crucial to long term performance of SOFCs. In this paper, we employ an integrated experimental/modeling approach to quantify the interfacial strength and to further predict the life of Crofer 22 APU as SOFC interconnect under isothermal cooling condition. The life of Crofer 22 APU was predicted by comparing the predicted interfacial strength, interfacial stresses induced by the cooling process from the operating temperature to room temperature, together with the growth kinetics of oxide scale with and without spinel coating. It was found that the interfacial strength between the oxide scale and Crofer 22 APU substrate decreases with the growth of the oxide scale. The interfacial strength of the oxide scale and spinel coating is much higher than that of the oxide scale and Crofer 22 APU substrate. With the spinel coating, the predicted life of the Crofer 22 APU is significantly longer than that of the uncoated Crofer 22 APU.

  15. Pulsed laser ablation growth and doping of epitaxial compound semiconductor films

    SciTech Connect (OSTI)

    Lowndes, D.H.; Rouleau, C.M.; Geohegan, D.B.; Budai, J.D.; Poker, D.B. [Oak Ridge National Lab., TN (United States). Solid State Div.; Puretzky, A.A. [Inst. of Spectroscopy, Troitsk (Russian Federation); Strauss, M.A.; Pedraza, A.J.; Park, J.W. [Univ. of Tennessee, Knoxville, TN (United States)

    1995-12-01T23:59:59.000Z

    Pulsed laser ablation (PLA) has several characteristics that are potentially attractive for the growth and doping of chemically complex compound semiconductors including (1) stoichiometric (congruent) transfer of composition from target to film, (2) the use of reactive gases to control film composition and/or doping via energetic-beam-induced reactions, and (3) low-temperature nonequilibrium phase formation in the laser-generated plasma ``plume.`` However, the electrical properties of compound semiconductors are far more sensitive to low concentrations of defects than are the oxide metals/ceramics for which PLA has been so successful. Only recently have doped epitaxial compound semiconductor films been grown by PLA. Fundamental studies are being carried out to relate film electrical and microstructural properties to the energy distribution of ablated species, to the temporal evolution of the ablation pulse in ambient gases, and to beam assisted surface and/or gas-phase reactions. In this paper the authors describe results of ex situ Hall effect, high-resolution x-ray diffraction, transmission electron microscopy, and Rutherford backscattering measurements that are being used in combination with in situ RHEED and time-resolved ion probe measurements to evaluate PLA for growth of doped epitaxial compound semiconductor films and heterostructures. Examples are presented and results analyzed for doped II-VI, I-III-VI, and column-III nitride materials grown recently in this and other laboratories.

  16. 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. ...

  17. 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 ...

  18. Autothermal oxidative pyrolysis of biomass feedstocks over noble metal catalysts to liquid products.

    E-Print Network [OSTI]

    Balonek, Christine Marie

    2011-01-01T23:59:59.000Z

    ??Two thermal processing technologies have emerged for processing biomass into renewable liquid products: pyrolysis and gasification/Fischer-Tropsch processing. The work presented here will demonstrate oxidative pyrolysis… (more)

  19. Engineering Escherichia coli for molecularly defined electron transfer to metal oxides and electrodes

    E-Print Network [OSTI]

    Jensen, Heather Marie

    2013-01-01T23:59:59.000Z

    A mediator-less microbial fuel cell using a metal reducingExperiments on a Microbial Fuel Cell. Science 1962, 137,from a miniature microbial fuel cell using Shewanella

  20. 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 ...

  1. INVESTIGATION OF MIXED METAL SORBENT/CATALYSTS FOR THE SIMULTANEOUS REMOVAL OF SULFUR AND NITROGEN OXIDES

    SciTech Connect (OSTI)

    Ates Akyurtlu; Jale F. Akyurtlu

    2000-04-10T23:59:59.000Z

    Simultaneous removal of SO{sub 2} and NO{sub x} using a regenerable solid sorbent will constitute an important improvement over the use of separate processes for the removal of these two pollutants from stack gases and possibly eliminate several shortcomings of the individual SO{sub 2} and NO{sub x} removal operations. The work done at PETC and the DOE-funded investigation of the investigators on the sulfation and regeneration of alumina-supported cerium oxide sorbents have shown that they can perform well at relatively high temperatures (823-900 K) as regenerable desulfurization sorbents. Survey of the recent literature shows that addition of copper oxide to ceria lowers the sulfation temperature of ceria down to 773 K, sulfated ceria-based sorbents can function as selective SCR catalysts even at elevated temperatures, SO{sub 2} can be directly reduced to sulfur by CO on CuO-ceria catalysts, and ceria-based catalysts may have a potential for selective catalytic reduction of NO{sub x} by methane. These observations indicate a possibility of developing a ceria-based sorbent/catalyst which can remove both SO{sub 2} and NO{sub x} from flue gases within a relatively wide temperature window, produce significant amounts of elemental sulfur during regeneration, and use methane for the selective catalytic reduction of NO{sub x}. The objective of this research is to conduct kinetic and parametric studies of the selective catalytic reduction of NO{sub x} with NH{sub 3} and CH{sub 4} over alumina-supported cerium oxide and copper oxide-cerium oxide sorbent/catalysts; investigate SO{sub 2} removal at lower temperatures by supported copper oxide-cerium oxide sorbents; and investigate the possibility of elemental sulfur production during regeneration with CO or with CH{sub 4}-air mixtures.

  2. INVESTIGATION OF MIXED METAL SORBENT/CATALYSTS FOR THE SIMULTANEOUS REMOVAL OF SULFUR AND NITROGEN OXIDES

    SciTech Connect (OSTI)

    Ates Akyurtlu; Jale F. Akyurtlu

    1999-11-30T23:59:59.000Z

    Simultaneous removal of SO{sub 2} and NO{sub x} using a regenerable solid sorbent will constitute an important improvement over the use of separate processes for the removal of these two pollutants from stack gases and possibly eliminate several shortcomings of the individual SO{sub 2} and NO{sub x} removal operations. The work done at PETC and the DOE-funded research of the investigators on the sulfation and regeneration of alumina-supported cerium oxide sorbents have shown that they can perform well at relatively high temperatures (823-900 K) as regenerable desulfurization sorbents. Survey of the recent literature shows that addition of copper oxide to ceria lowers the sulfation temperature of ceria down to 773 K, sulfated ceria-based sorbents can function as selective SCR catalysts even at elevated temperatures, SO{sub 2} can be directly reduced to sulfur by CO on CuO-ceria catalysts, and ceria-based catalysts may have a potential for selective catalytic reduction of NO{sub x} by methane. These observations indicate a possibility of developing a ceria-based sorbent/catalyst which can remove both SO{sub 2} and NO{sub x} from flue gases within a relatively wide temperature window, produce significant amounts of elemental sulfur during regeneration, and use methane for the selective catalytic reduction of NO{sub x}. The objective of this research is to conduct kinetic and parametric studies of the selective catalytic reduction of NO{sub x} with NH{sub 3} and CH{sub 4} over alumina-supported cerium oxide and copper oxide-cerium oxide sorbent/catalysts; investigate SO{sub 2} removal at lower temperatures by supported copper oxide-cerium oxide sorbents; and investigate the possibility of elemental sulfur production during regeneration with CO or with CH{sub 4} air mixtures.

  3. Investigation of mixed metal sorbent/catalysts for the simultaneous removal of sulfur and nitrogen oxides

    SciTech Connect (OSTI)

    Akyurtlu, A.; Akyurtlu, J.F.

    1999-03-31T23:59:59.000Z

    Simultaneous removal of SO{sub 2} and NO{sub x} using a regenerable solid sorbent will constitute an important improvement over the use of separate processes for the removal of these two pollutants from stack gases and possibly eliminate several shortcomings of the individual SO{sub 2} and NO{sub x} removal operations. The work done at PETC and the DOE-funded investigation of the investigators on the sulfation and regeneration of alumina-supported cerium oxide sorbents have shown that they can perform well at relatively high temperatures (823-900 K) as regenerable desulfurization sorbents. Survey of the recent literature shows that addition of copper oxide to ceria lowers the sulfation temperature of ceria down to 773 K, sulfated ceria-based sorbents can function as selective SCR catalysts even at elevated temperatures, SO{sub 2} can be directly reduced to sulfur by CO on CuO-ceria catalysts, and ceria-based catalysts may have a potential for selective catalytic reduction of NO{sub x} by methane. These observations indicate a possibility of developing a ceria-based sorbent/catalyst which can remove both SO{sub 2} and NO{sub x} from flue gases within a relatively wide temperature window, produce significant amounts of elemental sulfur during regeneration, and use methane for the selective catalytic reduction of NO{sub x}. The objective of this research is to conduct kinetic and parametric studies of the selective catalytic reduction of NO{sub x} with NH{sub 3} and CH{sub 4} over alumina-supported cerium oxide and copper oxide-cerium oxide sorbent/catalysts; investigate SO{sub 2} removal at lower temperatures by supported copper oxide-cerium oxide sorbents; and investigate the possibility of elemental sulfur production during regeneration with CO or with CH{sub 4}-air mixtures.

  4. 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.

  5. Photo-oxidation catalysts

    DOE Patents [OSTI]

    Pitts, J. Roland (Lakewood, CO); Liu, Ping (Irvine, CA); Smith, R. Davis (Golden, CO)

    2009-07-14T23:59:59.000Z

    Photo-oxidation catalysts and methods for cleaning a metal-based catalyst are disclosed. An exemplary catalyst system implementing a photo-oxidation catalyst may comprise a metal-based catalyst, and a photo-oxidation catalyst for cleaning the metal-based catalyst in the presence of light. The exposure to light enables the photo-oxidation catalyst to substantially oxidize absorbed contaminants and reduce accumulation of the contaminants on the metal-based catalyst. Applications are also disclosed.

  6. Synthesis and characterization of some metal oxide nanocrystals by microwave irradiation

    SciTech Connect (OSTI)

    Rashad, M.; Gaber, A.; Abdelrahim, M. A.; Abdel-Baset, A. M. [Physics Department, Faculty of Science, Assiut University, 71516 Assiut (Egypt); Moharram, A. H. [Physics Dept., College of Science and Arts, King Abdulaziz Univ., Rabigh 21911 (Saudi Arabia)

    2013-12-16T23:59:59.000Z

    Copper oxide and cobalt oxide (CuO, Co3O4) nanocrystals (NCs) have been successfully prepared in a short time using microwave irradiation. The resulted powders of nanocrystals (NCs) were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Thermogravimetric analysis (TGA) measurements are also studied. Fourier-transform infrared (FT-IR) and UV–visible absorption spectroscopy of both kind of nanoparticels are illustrated. Optical absorption analysis indicated the direct band gap for both kinds of nanocrystals.

  7. Laser Desorption/Ionization of Transition Metal Atoms and Oxides from Solid Argon Lester Andrews,*, Andreas Rohrbacher, Christopher M. Laperle, and Robert E. Continetti

    E-Print Network [OSTI]

    Continetti, Robert E.

    , approximately 10% of the gas sample condensed on the 10K copper plate. For ablation a focused (10 cm f of the laser-ablated metal atoms and O2 in excess argon during condensation at 10 K, have been laser desorbed spectrometry. Adding the C6H5Br chromophore to the Ar/O2 gas mixture also enhanced the metal and oxide ion

  8. Unitary lens semiconductor device

    DOE Patents [OSTI]

    Lear, Kevin L. (Albuquerque, NM)

    1997-01-01T23:59:59.000Z

    A unitary lens semiconductor device and method. The unitary lens semiconductor device is provided with at least one semiconductor layer having a composition varying in the growth direction for unitarily forming one or more lenses in the semiconductor layer. Unitary lens semiconductor devices may be formed as light-processing devices such as microlenses, and as light-active devices such as light-emitting diodes, photodetectors, resonant-cavity light-emitting diodes, vertical-cavity surface-emitting lasers, and resonant cavity photodetectors.

  9. A micromechanical model of oxidation effects in SiC/Ti metal matrix composites

    E-Print Network [OSTI]

    Wittig, Laurrie Ann

    1993-01-01T23:59:59.000Z

    . . Oxidation of Titanium and Titanium Alloys. . FORMULATION OF THE DIFFUSION EQUATION. . . . . The Mechanics of Diffusion. . Finite Element Formulation. . THEROMECHANICAL GOVERNING EQUATIONS. . . . . . PROBLEM SPECIFICS. . Diffusion Application Procedure... higher specific strength and temperature capabilities essential for successful implementation of these projects[1]. Titanium-based composites offer high temperature capabilities and are envisioned for such applications as aircratl skin, internal...

  10. Method of producing highly oxidized superconductors containing barium, copper, and a third metal

    DOE Patents [OSTI]

    Morris, Donald E. (Kensington, CA)

    1996-01-01T23:59:59.000Z

    Novel superconducting materials in the form of compounds, structures or phases are formed by performing otherwise known syntheses in a highly oxidizing atmosphere rather than that created by molecular oxygen at atmospheric pressure or below. This leads to the successful synthesis of novel superconducting compounds which are thermodynamically stable at the conditions under which they are formed.

  11. Method of producing highly oxidized superconductors containing barium, copper, and a third metal

    DOE Patents [OSTI]

    Morris, D.E.

    1996-02-20T23:59:59.000Z

    Novel superconducting materials in the form of compounds, structures or phases are formed by performing otherwise known syntheses in a highly oxidizing atmosphere rather than that created by molecular oxygen at atmospheric pressure or below. This leads to the successful synthesis of novel superconducting compounds which are thermodynamically stable at the conditions under which they are formed. 16 figs.

  12. 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

    of a viable flat panel display, low voltage, conductive phosphors which emit blue, red, and green light will be required for the field emission technology. This thesis examines zinc oxide (ZnO) based thin ( ) phosphors for such an application. ZnO is a...

  13. Uniformly Embedded Metal Oxide Nanoparticles in Vertically Aligned Carbon Nanotube Forests as Pseudocapacitor Electrodes for

    E-Print Network [OSTI]

    Lin, Liwei

    applications. A vacuum-assisted, in situ electrodeposition process has been used to achieve the three-dimensional functionalization of CNT forests with inserted nickel nanoparticles as pseudocapacitor electrodes. Experimental CNT forest samples, and the oxidized nickel nanoparticle/CNT supercapacitor retained 94.2% of its

  14. Europium-activated phosphors containing oxides of rare-earth and group-IIIB metals and method of making the same

    DOE Patents [OSTI]

    Comanzo, Holly Ann; Setlur, Anant Achyut; Srivastava, Alok Mani; Manivannan, Venkatesan

    2004-07-13T23:59:59.000Z

    Europium-activated phosphors comprise oxides of at least a rare-earth metal selected from the group consisting of gadolinium, yttrium, lanthanum, and combinations thereof and at least a Group-IIIB metal selected from the group consisting of aluminum, gallium, indium, and combinations thereof. A method for making such phosphors comprises adding at least a halide of at least one of the selected Group-IIIB metals in a starting mixture. The method further comprises firing the starting mixture in an oxygen-containing atmosphere. The phosphors produced by such a method exhibit improved absorption in the UV wavelength range and improved quantum efficiency.

  15. Europium-activated phosphors containing oxides of rare-earth and group-IIIB metals and method of making the same

    DOE Patents [OSTI]

    Comanzo, Holly Ann; Setlur, Anant Achyut; Srivastava, Alok Mani

    2006-04-04T23:59:59.000Z

    Europium-activated phosphors comprise oxides of at least a rare-earth metal selected from the group consisting of gadolinium, yttrium, lanthanum, and combinations thereof and at least a Group-IIIB metal selected from the group consisting of aluminum, gallium, indium, and combinations thereof. A method for making such phosphors comprises adding at least a halide of at least one of the selected Group-IIIB metals in a starting mixture. The method further comprises firing the starting mixture in an oxygen-containing atmosphere. The phosphors produced by such a method exhibit improved absorption in the UV wavelength range and improved quantum efficiency.

  16. Use of impure inert gases in the controlled heating and cooling of mixed conducting metal oxide materials

    DOE Patents [OSTI]

    Carolan, Michael Francis (Allentown, PA); Bernhart, John Charles (Fleetwood, PA)

    2012-08-21T23:59:59.000Z

    Method for processing an article comprising mixed conducting metal oxide material. The method comprises contacting the article with an oxygen-containing gas and either reducing the temperature of the oxygen-containing gas during a cooling period or increasing the temperature of the oxygen-containing gas during a heating period; during the cooling period, reducing the oxygen activity in the oxygen-containing gas during at least a portion of the cooling period and increasing the rate at which the temperature of the oxygen-containing gas is reduced during at least a portion of the cooling period; and during the heating period, increasing the oxygen activity in the oxygen-containing gas during at least a portion of the heating period and decreasing the rate at which the temperature of the oxygen-containing gas is increased during at least a portion of the heating period.

  17. Helicon wave excitation to produce energetic electrons for manufacturing semiconductors

    DOE Patents [OSTI]

    Molvik, Arthur W. (Livermore, CA); Ellingboe, Albert R. (Fremont, CA)

    1998-01-01T23:59:59.000Z

    A helicon plasma source is controlled by varying the axial magnetic field or rf power controlling the formation of the helicon wave. An energetic electron current is carried on the wave when the magnetic field is 90 G; but there is minimal energetic electron current when the magnetic field is 100 G in one particular plasma source. Similar performance can be expected from other helicon sources by properly adjusting the magnetic field and power to the particular geometry. This control for adjusting the production of energetic electrons can be used in the semiconductor and thin-film manufacture process. By applying energetic electrons to the insulator layer, such as silicon oxide, etching ions are attracted to the insulator layer and bombard the insulator layer at higher energy than areas that have not accumulated the energetic electrons. Thus, silicon and metal layers, which can neutralize the energetic electron currents will etch at a slower or non-existent rate. This procedure is especially advantageous in the multilayer semiconductor manufacturing because trenches can be formed that are in the range of 0.18-0.35 mm or less.

  18. Helicon wave excitation to produce energetic electrons for manufacturing semiconductors

    DOE Patents [OSTI]

    Molvik, A.W.; Ellingboe, A.R.

    1998-10-20T23:59:59.000Z

    A helicon plasma source is controlled by varying the axial magnetic field or rf power controlling the formation of the helicon wave. An energetic electron current is carried on the wave when the magnetic field is 90 G; but there is minimal energetic electron current when the magnetic field is 100 G in one particular plasma source. Similar performance can be expected from other helicon sources by properly adjusting the magnetic field and power to the particular geometry. This control for adjusting the production of energetic electrons can be used in the semiconductor and thin-film manufacture process. By applying energetic electrons to the insulator layer, such as silicon oxide, etching ions are attracted to the insulator layer and bombard the insulator layer at higher energy than areas that have not accumulated the energetic electrons. Thus, silicon and metal layers, which can neutralize the energetic electron currents will etch at a slower or non-existent rate. This procedure is especially advantageous in the multilayer semiconductor manufacturing because trenches can be formed that are in the range of 0.18--0.35 mm or less. 16 figs.

  19. Au/MxOy/TiO2 catalysts for CO oxidation: promotional effect of main-group, transition, and rare-earth metal oxide additives.

    SciTech Connect (OSTI)

    Ma, Zhen [ORNL; Overbury, Steven {Steve} H [ORNL; Dai, Sheng [ORNL

    2007-01-01T23:59:59.000Z

    Au/TiO2 catalysts are active for CO oxidation, but they suffer from high-temperature sintering of the gold particles, and few attempts have been made to promote or stabilize Au/TiO2. Our recent communication addressed these issues by loading gold onto Al2O3/TiO2 prepared via surface-sol-gel processing of Al(sec-OC4H9)3 on TiO2. In our current full paper, Au/Al2O3/TiO2 catalysts were prepared alternatively by thermal decomposition of Al(NO3)3 on TiO2 followed by loading gold, and the influences of the decomposition temperature and Al2O3 content were systematically surveyed. This facile method was subsequently extended to the preparation of a battery of metal oxide-modified Au/TiO2 catalysts virtually not reported. It was found that Au/TiO2 modified by CaO, NiO, ZnO, Ga2O3, Y2O3, ZrO2, La2O3, Pr2O3, Nd2O3, Sm2O3, Eu2O3, Gd2O3, Dy2O3, Ho2O3, Er2O3, or Yb2O3 could retain significant activity at ambient temperature even after aging in O2-He at 500 C, whereas unmodified Au/TiO2 lost its activity. Moreover, some 200 C-calcined promoted catalysts showed high activity even at about -100 C. The deactivation and regeneration of some of these new catalysts were studied. This work furnished novel catalysts for further fundamental and applied research.

  20. Design and construction of a radiation resistant quadrupole using metal oxide insulated CICC

    SciTech Connect (OSTI)

    Albert F. Zeller

    2012-12-28T23:59:59.000Z

    The construction of a engineering test model of a radiation resistant quadrupole is described. The cold-iron quadrupole uses coils fabricated from metal-oixide (synthetic spinel) insulated Cable-In-Conduit-Conductor (CICC). The superconductor is NbTi in a copper matrix. The quadrupole is designed to produce a pole-tip field of 2 T with an operating current of 7,000 A.

  1. Method for improving the oxidation-resistance of metal substrates coated with thermal barrier coatings

    DOE Patents [OSTI]

    Thompson, Anthony Mark (Niskayuna, NY); Gray, Dennis Michael (Delanson, NY); Jackson, Melvin Robert (Niskayuna, NY)

    2002-01-01T23:59:59.000Z

    A method for providing a protective coating on a metal-based substrate is disclosed. The method involves the application of an aluminum-rich mixture to the substrate to form a discontinuous layer of aluminum-rich particles, followed by the application of a second coating over the discontinuous layer of aluminum-rich particles. Aluminum diffuses from the aluminum-rich layer into the substrate, and into any bond coat layer which is subsequently applied. Related articles are also described.

  2. INL Internship:Modification of Metal Contaminants on Oxide Surfaces Modified by Laser Irradiation

    SciTech Connect (OSTI)

    Michael J. Hansen; Robert Fox; Les Manner

    2006-08-01T23:59:59.000Z

    This project focuses on obtaining the optimal laser parameters needed for enhancing metal contaminants on cement, granite, and marble. The various parameters of the laser tested include the fluence, wavelength, and frequency. A chelating study was also performed in order to increase the volatility of cobalt. In the following paper each experiment is described in detail. No results are included in this report because their release is not approved and they could eventually become classified.

  3. Noble Metal-Free Reduced Graphene Oxide-ZnxCd1-xS Nanocomposite with Enhanced Solar Photocatalytic H2Production

    E-Print Network [OSTI]

    Gong, Jian Ru

    solar energy by production of hydrogen from water splitting is of great importance from both theoretical strategy for solving simultaneously the incoming energy and environmental problems.2 So far, numerousNoble Metal-Free Reduced Graphene Oxide-ZnxCd1-xS Nanocomposite with Enhanced Solar Photocatalytic

  4. Molybdenum-based additives to mixed-metal oxides for use in hot gas cleanup sorbents for the catalytic decomposition of ammonia in coal gases

    DOE Patents [OSTI]

    Ayala, Raul E. (Clifton Park, NY)

    1993-01-01T23:59:59.000Z

    This invention relates to additives to mixed-metal oxides that act simultaneously as sorbents and catalysts in cleanup systems for hot coal gases. Such additives of this type, generally, act as a sorbent to remove sulfur from the coal gases while substantially simultaneously, catalytically decomposing appreciable amounts of ammonia from the coal gases.

  5. Understanding Atom Probe Tomography of Oxide-Supported Metal Nanoparticles by Correlation with Atomic Resolution Electron Microscopy and Field Evaporation Simulation

    SciTech Connect (OSTI)

    Devaraj, Arun; Colby, Robert J.; Vurpillot, F.; Thevuthasan, Suntharampillai

    2014-03-26T23:59:59.000Z

    Metal-dielectric composite materials, specifically metal nanoparticles supported on or embedded in metal oxides, are widely used in catalysis. The accurate optimization of such nanostructures warrants the need for detailed three-dimensional characterization. Atom probe tomography is uniquely capable of generating sub-nanometer structural and compositional data with part-per-million mass sensitivity, but there are reconstruction artifacts for composites containing materials with strongly differing fields of evaporation, as for oxide-supported metal nanoparticles. By correlating atom probe tomography with scanning transmission electron microscopy for Au nanoparticles embedded in an MgO support, deviations from an ideal topography during evaporation are demonstrated directly, and correlated with compositional errors in the reconstructed data. Finite element simulations of the field evaporation process confirm that protruding Au nanoparticles will evolve on the tip surface, and that evaporation field variations lead to an inaccurate assessment of the local composition, effectively lowering the spatial resolution of the final reconstructed dataset. Cross-correlating the experimental data with simulations results in a more detailed understanding of local evaporation aberrations during APT analysis of metal-oxide composites, paving the way towards a more accurate three-dimensional characterization of this technologically important class of materials.

  6. Role of the dielectric for the charging dynamics of the dielectric/barrier interface in AlGaN/GaN based metal-insulator-semiconductor structures under forward gate bias stress

    SciTech Connect (OSTI)

    Lagger, P., E-mail: peter.lagger@infineon.com [Infineon Technologies Austria AG, Siemensstraße 2, 9500 Villach (Austria); Institute of Solid State Electronics, Vienna University of Technology, Floragasse 7, 1040 Wien (Austria); Steinschifter, P.; Reiner, M.; Stadtmüller, M.; Denifl, G.; Ostermaier, C. [Infineon Technologies Austria AG, Siemensstraße 2, 9500 Villach (Austria); Naumann, A.; Müller, J.; Wilde, L.; Sundqvist, J. [Fraunhofer IPMS-CNT, Königsbrücker Straße 178, 01099 Dresden (Germany); Pogany, D. [Institute of Solid State Electronics, Vienna University of Technology, Floragasse 7, 1040 Wien (Austria)

    2014-07-21T23:59:59.000Z

    The high density of defect states at the dielectric/III-N interface in GaN based metal-insulator-semiconductor structures causes tremendous threshold voltage drifts, ?V{sub th}, under forward gate bias conditions. A comprehensive study on different dielectric materials, as well as varying dielectric thickness t{sub D} and barrier thickness t{sub B}, is performed using capacitance-voltage analysis. It is revealed that the density of trapped electrons, ?N{sub it}, scales with the dielectric capacitance under spill-over conditions, i.e., the accumulation of a second electron channel at the dielectric/AlGaN barrier interface. Hence, the density of trapped electrons is defined by the charging of the dielectric capacitance. The scaling behavior of ?N{sub it} is explained universally by the density of accumulated electrons at the dielectric/III-N interface under spill-over conditions. We conclude that the overall density of interface defects is higher than what can be electrically measured, due to limits set by dielectric breakdown. These findings have a significant impact on the correct interpretation of threshold voltage drift data and are of relevance for the development of normally off and normally on III-N/GaN high electron mobility transistors with gate insulation.

  7. Electrical and structural characterization of metal germanides.

    E-Print Network [OSTI]

    Chawanda, Albert

    2011-01-01T23:59:59.000Z

    ??Metal-semiconductor contacts have been widely studied in the past 60 years. These structures are of importance in the microelectronics industry. As the scaling down of… (more)

  8. Synthesis and characterization of metal oxide materials for thermochemical CO2 splitting using concentrated solar energy.

    SciTech Connect (OSTI)

    Stechel, Ellen Beth; Ambrosini, Andrea; Coker, Eric Nicholas; Rodriguez, Mark Andrew; Miller, James Edward; Evans, Lindsey R.; Livers, Stephanie

    2010-07-01T23:59:59.000Z

    The Sunshine to Petrol effort at Sandia aims to convert carbon dioxide and water to precursors for liquid hydrocarbon fuels using concentrated solar power. Significant advances have been made in the field of solar thermochemical CO{sub 2}-splitting technologies utilizing yttria-stabilized zirconia (YSZ)-supported ferrite composites. Conceptually, such materials work via the basic redox reactions: Fe{sub 3}O{sub 4} {yields} 3FeO + 0.5O{sub 2} (Thermal reduction, >1350 C) and 3FeO + CO{sub 2} {yields} Fe{sub 3}O{sub 4} + CO (CO{sub 2}-splitting oxidation, <1200 C). There has been limited fundamental characterization of the ferrite-based materials at the high temperatures and conditions present in these cycles. A systematic study of these composites is underway in an effort to begin to elucidate microstructure, structure-property relationships, and the role of the support on redox behavior under high-temperature reducing and oxidizing environments. In this paper the synthesis, structural characterization (including scanning electron microscopy and room temperature and in-situ x-ray diffraction), and thermogravimetric analysis of YSZ-supported ferrites will be reported.

  9. INVESTIGATION OF MIXED METAL SORBENT/CATALYSTS FOR THE SIMULTANEOUS REMOVAL OF SULFUR AND NITROGEN OXIDES

    SciTech Connect (OSTI)

    Ates Akyurtlu; Jale F. Akyurtle

    2001-08-01T23:59:59.000Z

    Simultaneous removal of SO{sub 2} and NO{sub x} using a regenerable solid sorbent will constitute an important improvement over the use of separate processes for the removal of these two pollutants from stack gases and possibly eliminate several shortcomings of the individual SO{sub 2} and NO{sub x} removal operations. The work done at PETC and the DOE-funded investigation of the investigators on the sulfation and regeneration of alumina-supported cerium oxide sorbents have shown that they can perform well at relatively high temperatures (823-900 K) as regenerable desulfurization sorbents. Survey of the recent literature shows that addition of copper oxide to ceria lowers the sulfation temperature of ceria down to 773 K, sulfated ceria-based sorbents can function as selective SCR catalysts even at elevated temperatures, SO{sub 2} can be directly reduced to sulfur by CO on CuO-ceria catalysts, and ceria-based catalysts may have a potential for selective catalytic reduction of NO{sub x} by methane. These observations indicate a possibility of developing a ceria-based sorbent/catalyst which can remove both SO{sub 2} and NO{sub x} from flue gases within a relatively wide temperature window, produce significant amounts of elemental sulfur during regeneration, and use methane for the selective catalytic reduction of NO{sub x}.

  10. Development of carbon-metal oxide supercapacitors from sol-gel derived carbon-ruthenium xerogels

    SciTech Connect (OSTI)

    Lin, C.; Ritter, J.A.; Popov, B.N.

    1999-09-01T23:59:59.000Z

    There has been increasing interest in electrochemical capacitors as energy storage systems because of their high power density and long cycle life, compared to battery devices. According to the mechanism of energy storage, there are two types of electrochemical capacitors. One type is based on double layer (dl) formation due to charge separation, and the other type is based on a faradaic process due to redox reactions. Sol-gel derived high surface area carbon-ruthenium xerogels were prepared from carbonized resorcinol-formaldehyde resins containing an electrochemically active form of ruthenium oxide. The electrochemical capacitance of these materials increased with an increase in the ruthenium content indicating the presence of pseudocapacitance associated with the ruthenium oxide undergoing reversible faradaic redox reactions. A specific capacitance of 256 F/g (single electrode) was obtained from a carbon xerogel containing 14 wt% Ru, which corresponded to more than 50% utilization of the ruthenium. The double layer accounted for 40% of this capacitance. This material was also electrochemically stable, showing no change in a cyclic voltammogram for over 2,000 cycles.

  11. Reaction of metal sulfates with molybdenum oxide, a high temperature reaction step for thermochemical cycles

    SciTech Connect (OSTI)

    Hollabaugh, C.M.; Wallace, T.C.; Bowman, M.G.; Jones, W.M.

    1980-01-01T23:59:59.000Z

    The reaction of sulfates with molybdenum oxide at high temperature was studied to determine the feasibility of using these reactions in a thermochemical process for making hydrogen. The experiments were performed by heating the blended powders to temperatures of 1075 K and higher and analyzing the evolved gas for acid content. It was found that the reaction rate over the first few minutes increased with both temperature and MoO/sub 3/. The fraction of sulfate reacting in the first 5 minutes varies with cation used. At 1125 K and for a molar ratio of sulfate ion/MoO/sub 3/ of 0.5, the fraction reacted was 0.29 for BaSO/sub 4/, 0.32 for CaSO/sub 4/ and 0.82 for La/sub 2/(SO/sub 4/)/sub 3/. These results are encouraging and indicate that an alternative means to sulfuric acid drying and decomposition is feasible using a mixed sulfate/oxide system to lower the effective decomposition temperature of the insoluble sulfate.

  12. Method For Improving The Oxidation Resistance Of Metal Substrates Coated With Thermal Barrier Coatings

    DOE Patents [OSTI]

    Thompson, Anthony Mark (Niskayuna, NY); Gray, Dennis Michael (Delanson, NY); Jackson, Melvin Robert (Niskayuna, NY)

    2003-05-13T23:59:59.000Z

    A method for providing a protective coating on a metal-based substrate is disclosed. The method involves the application of an aluminum-rich mixture to the substrate to form a discontinuous layer of aluminum-rich particles, followed by the application of a second coating over the discontinuous layer of aluminum-rich particles. Aluminum diffuses from the aluminum-rich layer into the substrate, and into any bond coat layer which is subsequently applied. Related articles are also described. A method for providing a protective coating on a metal-based substrate is disclosed. The method involves the application of an aluminum-rich mixture to the substrate to form a discontinuous layer of aluminum-rich particles, followed by the application of a second coating over the discontinuous layer of aluminum-rich particles. Aluminum diffuses from the aluminum-rich layer into the substrate, and into any bond coat layer which is subsequently applied. Related articles are also described.

  13. Semiconductor bridge (SCB) detonator

    DOE Patents [OSTI]

    Bickes, Jr., Robert W. (Albuquerque, NM); Grubelich, Mark C. (Albuquerque, NM)

    1999-01-01T23:59:59.000Z

    The present invention is a low-energy detonator for high-density secondary-explosive materials initiated by a semiconductor bridge igniter that comprises a pair of electrically conductive lands connected by a semiconductor bridge. The semiconductor bridge is in operational or direct contact with the explosive material, whereby current flowing through the semiconductor bridge causes initiation of the explosive material. Header wires connected to the electrically-conductive lands and electrical feed-throughs of the header posts of explosive devices, are substantially coaxial to the direction of current flow through the SCB, i.e., substantially coaxial to the SCB length.

  14. Semiconductor bridge (SCB) detonator

    DOE Patents [OSTI]

    Bickes, R.W. Jr.; Grubelich, M.C.

    1999-01-19T23:59:59.000Z

    The present invention is a low-energy detonator for high-density secondary-explosive materials initiated by a semiconductor bridge (SCB) igniter that comprises a pair of electrically conductive lands connected by a semiconductor bridge. The semiconductor bridge is in operational or direct contact with the explosive material, whereby current flowing through the semiconductor bridge causes initiation of the explosive material. Header wires connected to the electrically-conductive lands and electrical feed-throughs of the header posts of explosive devices, are substantially coaxial to the direction of current flow through the SCB, i.e., substantially coaxial to the SCB length. 3 figs.

  15. High-resolution structural studies of ultra-thin magnetic, transition metal overlayers and two-dimensional transition metal oxides using synchrotron radiation

    SciTech Connect (OSTI)

    Kellar, S.A. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; [Lawrence Berkeley National Lab., CA (United States). Advanced Light Source Div.

    1997-05-01T23:59:59.000Z

    This thesis report the surface-structure determination of three, ultra-thin magnetic transition-metal films, Fe/Au(100), Mn/Ni(100), and Mn/Cu(100) using Angle-Resolved Photoemission Extended Fine Structure (ARPEFS) and photoelectron holography. These structural studies are the first to use non-s initial states in the ARPEFS procedure. This thesis also reports an ARPEFS surface-structure determination of a two-dimensional transition-metal oxide, [(1 x 1)O/W(110)] x 12. The authors have analyzed the ARPFES signal from the Au 4f{sub 7/5} core level of the Au(1 ML)/Fe(15 ML)/Au(100) system. The analysis shows that the Fe grows layer by layer with one monolayer of gold, acting as a surfactant, remaining on top of the growing Fe layers. These surface gold atoms sit in the four-fold hollow site, 1.67 {+-} 0.02 A above the iron surface. The grown Fe layer is very much like the bulk, bcc iron, with an interlayer spacing of 1.43 {+-} 0.03 A. Analysis of the Mn 3p ARPEFS signals from c(2 x 2)Mn/Ni(100) and c(2 x 2)Mn/Cu(100) shows that the Mn forms highly corrugated surface alloys. The corrugation of the Mn/Ni(100) and Mn/Cu(100) systems are 0.24 {+-} 0.02 A and 0.30 {+-} 0.04 A respectively. In both cases the Mn is sticking above the plane of the surface substrate atoms. For the Mn/Ni(100) system the first layer Ni is contracted 4% from the bulk value. The Mn/Cu(100) system shows bulk spacing for the substrate Cu. Photoelectron holography shows that the Mn/Ni interface is very abrupt with very little Mn leaking into the second layer, while the Mn/Cu(100) case has a significant amount of Mn leaking into the second layer. A new, five-element electrostatic electron lens was developed for hemispherical electron-energy analyzers. This lens system can be operated at constant transverse or constants angular magnification, and has been optimized for use with the very small photon-spot sizes. Improvements to the hemispherical electron-energy analyzer are also discussed.

  16. THE COORDINATION CHEMISTRY OF METAL SURFACES

    E-Print Network [OSTI]

    Muetterties, Earl L.

    2013-01-01T23:59:59.000Z

    result 7 ' 30 u 31 in metal carbide cluster chemistry willin metal chemistry. Oxidation of the iron carbide cluster

  17. 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.

  18. Thin Film Reliability SEMICONDUCTORS

    E-Print Network [OSTI]

    Thin Film Reliability SEMICONDUCTORS Our goal is to develop new ways to evaluate the reliability $250 billion per year. As semiconductor devices become ultra miniaturized, reliability testing becomes-world conditions as possible will enable product designers to better balance performance and reliability

  19. Roles of Glutamates and Metal ions in a Rationally Designed Nitric Oxide Reductase Based on Myoglobin

    SciTech Connect (OSTI)

    Y Lin; N Yeung; Y Gao; K Miner; S Tian; H Robinson; Y Lu

    2011-12-31T23:59:59.000Z

    A structural and functional model of bacterial nitric oxide reductase (NOR) has been designed by introducing two glutamates (Glu) and three histidines (His) in sperm whale myoglobin. X-ray structural data indicate that the three His and one Glu (V68E) residues bind iron, mimicking the putative FeB site in NOR, while the second Glu (I107E) interacts with a water molecule and forms a hydrogen bonding network in the designed protein. Unlike the first Glu (V68E), which lowered the heme reduction potential by {approx}110 mV, the second Glu has little effect on the heme potential, suggesting that the negatively charged Glu has a different role in redox tuning. More importantly, introducing the second Glu resulted in a {approx}100% increase in NOR activity, suggesting the importance of a hydrogen bonding network in facilitating proton delivery during NOR reactivity. In addition, EPR and X-ray structural studies indicate that the designed protein binds iron, copper, or zinc in the FeB site, each with different effects on the structures and NOR activities, suggesting that both redox activity and an intermediate five-coordinate heme-NO species are important for high NOR activity. The designed protein offers an excellent model for NOR and demonstrates the power of using designed proteins as a simpler and more well-defined system to address important chemical and biological issues.

  20. 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.

  1. Reduction of native oxides on InAs by atomic layer deposited Al{sub 2}O{sub 3} and HfO{sub 2}

    SciTech Connect (OSTI)

    Timm, R.; Fian, A.; Hjort, M.; Thelander, C.; Lind, E.; Andersen, J. N.; Wernersson, L.-E.; Mikkelsen, A. [Department of Physics, Nanometer Structure Consortium, Lund University, P.O. Box 118, 22 100 Lund (Sweden)

    2010-09-27T23:59:59.000Z

    Thin high-{kappa} oxide films on InAs, formed by atomic layer deposition, are the key to achieve high-speed metal-oxide-semiconductor devices. We have studied the native oxide and the interface between InAs and 2 nm thick Al{sub 2}O{sub 3} or HfO{sub 2} layers using synchrotron x-ray photoemission spectroscopy. Both films lead to a strong oxide reduction, obtaining less than 10% of the native As-oxides and between 10% and 50% of the native In-oxides, depending on the deposition temperature. The ratio of native In- to As-oxides is determined to be 2:1. The exact composition and the influence of different oxidation states and suboxides is discussed in detail.

  2. Photoelectrochemistry of Semiconductor Nanowire Arrays

    SciTech Connect (OSTI)

    Mallouk, Thomas E; Redwing, Joan M

    2009-11-10T23:59:59.000Z

    This project supported research on the growth and photoelectrochemical characterization of semiconductor nanowire arrays, and on the development of catalytic materials for visible light water splitting to produce hydrogen and oxygen. Silicon nanowires were grown in the pores of anodic aluminum oxide films by the vapor-liquid-solid technique and were characterized electrochemically. Because adventitious doping from the membrane led to high dark currents, silicon nanowire arrays were then grown on silicon substrates. The dependence of the dark current and photovoltage on preparation techniques, wire diameter, and defect density was studied for both p-silicon and p-indium phosphide nanowire arrays. The open circuit photovoltage of liquid junction cells increased with increasing wire diameter, reaching 350 mV for micron-diameter silicon wires. Liquid junction and radial p-n junction solar cells were fabricated from silicon nano- and microwire arrays and tested. Iridium oxide cluster catalysts stabilized by bidentate malonate and succinate ligands were also made and studied for the water oxidation reaction. Highlights of this project included the first papers on silicon and indium phosphide nanowire solar cells, and a new procedure for making ligand-stabilized water oxidation catalysts that can be covalently linked to molecular photosensitizers or electrode surfaces.

  3. Solubility of, and hydrogen ion adsorption on, some metal oxides in aqueous solutions to high temperatures

    SciTech Connect (OSTI)

    Palmer, D.A.; Benezeth, P.; Wesolowski, D.J.; Anovitz, L.M. [Oak Ridge National Lab., TN (United States); Machesky, M.L. [Illinois State Water Survey, Champaign, IL (United States); Hayashi, Ken-ichiro [Tohoku Univ., Sendai (Japan). Inst. of Mineralogy, Petrology and Economic Geology; Hyde, K.E. [State Univ. of New York, Oswego, NY (United States). Dept. of Chemistry

    1997-08-01T23:59:59.000Z

    Solubility of boehmite (AlOOH), ferrous hydroxide (Fe(OH)2)/magnetite (Fe3O4), zincite (ZnO), and brucite (Mg(OH)2) were measured over a range of temperatures (AlOOH, 100-290 C; Fe(OH)2/Fe3O4, 100-250 C; ZnO, 50-290 C; Mg(OH)2, 60-200 C) using in situ pH measurements. A hydrogen-electrode concentration cell was used; the pH range depended on the oxide. The solubility results for boehmite mainly demonstrate the method viability, while those for zincite are mainly restricted to mildly acidic to neutral pH where Zn{sup 2+} predominates in solution. The magnetite (presumably coated with Fe(OH)2) solubilities extend from pHs > 5 and, because of relevance to water/steam cycles of power plants, are compared in detail with previous studies. The same cell was used to investigate the surface adsorption-desorption thermodynamics of H ions on rutile (TiO2) and zincite to 290 C. Behavior of pH at zero-point-of-charge as function of temperature and application of the Stern-3-layer model were determined for this solid. The zincite study is still incomplete; preliminary results show trends that can be rationalized only qualitatively now with the zero- point-of-charge being apparently affected by hydration of the surface in basic solutions and specific adsorption of Na ions under the same conditions.

  4. In-situ X-ray photoelectron spectroscopy studies of water on metals and oxides at ambient conditions

    SciTech Connect (OSTI)

    Salmeron, Miquel; Yamamoto, S.; Bluhm, H.; Andersson, K.; Ketteler, G.; Ogasawara, H.; Salmeron, M.; Nilsson, A.

    2007-10-29T23:59:59.000Z

    X-ray photoelectron spectroscopy (XPS) is a powerful tool for surface and interface analysis, providing the elemental composition of surfaces and the local chemical environment of adsorbed species. Conventional XPS experiments have been limited to ultrahigh vacuum (UHV) conditions due to a short mean free path of electrons in a gas phase. The recent advances in instrumentation coupled with third-generation synchrotron radiation sources enables in-situ XPS measurements at pressures above 5 Torr. In this review, we describe the basic design of the ambient pressure XPS setup that combines differential pumping with an electrostatic focusing. We present examples of the application of in-situ XPS to studies of water adsorption on the surface of metals and oxides including Cu(110), Cu(111), TiO2(110) under environmental conditions of water vapor pressure. On all these surfaces we observe a general trend where hydroxyl groups form first, followed by molecular water adsorption. The importance of surface OH groups and their hydrogen bonding to water molecules in water adsorption on surfaces is discussed in detail.

  5. Comparative study of the reactions of metal oxides with H{sub 2}S and SO{sub 2}

    SciTech Connect (OSTI)

    Sotirchos, S.V.

    1992-12-31T23:59:59.000Z

    Primary objective was to investigate the effects of pore structure on capacity of porous metal oxides for removal of SO{sub 2} from power plant fuel gas and H{sub 2}S from hot coal gas. During this period, a comparative study was carried out on the direct reaction with H{sub 2}S and SO{sub 2} of the three limestones used as CaO precursors: Greer limestone, Georgia marble, and Iceland spar calcite. Sulfation was carried out at 750 and 850 C in a thermogravimetric analysis system under simulated high pressure (enough CO{sub 2} to prevent decomposition of CaCO{sub 3}). Results are presented as conversion vs time graphs. Mercury penetration and gas adsorption were used to analyze the structure. Activation energies and effective diffusivities were determined. A variable diffusivity shrinking-core model was used to analyze the data. In the future, this limestone study will be completed, and a study on supported CuO sorbent will be started.

  6. Comparative study of the reactions of metal oxides with H[sub 2]S and SO[sub 2

    SciTech Connect (OSTI)

    Sotirchos, S.V.

    1992-01-01T23:59:59.000Z

    Primary objective was to investigate the effects of pore structure on capacity of porous metal oxides for removal of SO[sub 2] from power plant fuel gas and H[sub 2]S from hot coal gas. During this period, a comparative study was carried out on the direct reaction with H[sub 2]S and SO[sub 2] of the three limestones used as CaO precursors: Greer limestone, Georgia marble, and Iceland spar calcite. Sulfation was carried out at 750 and 850 C in a thermogravimetric analysis system under simulated high pressure (enough CO[sub 2] to prevent decomposition of CaCO[sub 3]). Results are presented as conversion vs time graphs. Mercury penetration and gas adsorption were used to analyze the structure. Activation energies and effective diffusivities were determined. A variable diffusivity shrinking-core model was used to analyze the data. In the future, this limestone study will be completed, and a study on supported CuO sorbent will be started.

  7. Impact of Fission Products Impurity on the Plutonium Content of Metal- and Oxide- Fuels in Sodium Cooled Fast Reactors

    SciTech Connect (OSTI)

    Hikaru Hiruta; Gilles Youinou

    2013-09-01T23:59:59.000Z

    This short report presents the neutronic analysis to evaluate the impact of fission product impurity on the Pu content of Sodium-cooled Fast Reactor (SFR) metal- and oxide- fuel fabrication. The similar work has been previously done for PWR MOX fuel [1]. The analysis will be performed based on the assumption that the separation of the fission products (FP) during the reprocessing of UOX spent nuclear fuel assemblies is not perfect and that, consequently, a certain amount of FP goes into the Pu stream used to fabricate SFR fuels. Only non-gaseous FPs have been considered (see the list of 176 isotopes considered in the calculations in Appendix 1 of Reference 1). Throughout of this report, we define the mixture of Pu and FPs as PuFP. The main objective of this analysis is to quantify the increase of the Pu content of SFR fuels necessary to maintain the same average burnup at discharge independently of the amount of FP in the Pu stream, i.e. independently of the PuFP composition. The FP losses are considered element-independent, i.e., for example, 1% of FP losses mean that 1% of all non-gaseous FP leak into the Pu stream.

  8. Comparative study of the reactions of metal oxides with H sub 2 S and SO sub 2

    SciTech Connect (OSTI)

    Sotirchos, S.V.

    1991-10-01T23:59:59.000Z

    The primary objective of this project is the investigation of the effects of pore structure on the capacity of porous metal oxides for removal of gaseous pollutants from flue gases of power plants (SO{sub 2}) and hot coal gas (primarily H{sub 2}A). Specifically, we intend to appropriately exploit the differences of the sulfidation and sulfation reactions (for instance, different molar volumes of solid products) to elucidate the dependence of the sorptive capacity of a porous sorbent on its physical microstructure. The following tasks have been identified in the proposed project: (1) Literature survey and identification of solids to be used in experimental studies. (2) Experimental study of the reaction of the chosen solids with SO{sub 2} and/or H{sub 2}S. (3) Experimental study of the evolution of the structure of the solids during reaction with SO{sub 2} and/or H{sub 2}S using pore structure analysis and effective diffusivity measurements. (4) Model testing and validation using the obtained experimental data.

  9. Conductive layer for biaxially oriented semiconductor film growth

    DOE Patents [OSTI]

    Findikoglu, Alp T. (Los Alamos, NM); Matias, Vladimir (Santa Fe, NM)

    2007-10-30T23:59:59.000Z

    A conductive layer for biaxially oriented semiconductor film growth and a thin film semiconductor structure such as, for example, a photodetector, a photovoltaic cell, or a light emitting diode (LED) that includes a crystallographically oriented semiconducting film disposed on the conductive layer. The thin film semiconductor structure includes: a substrate; a first electrode deposited on the substrate; and a semiconducting layer epitaxially deposited on the first electrode. The first electrode includes a template layer deposited on the substrate and a buffer layer epitaxially deposited on the template layer. The template layer includes a first metal nitride that is electrically conductive and has a rock salt crystal structure, and the buffer layer includes a second metal nitride that is electrically conductive. The semiconducting layer is epitaxially deposited on the buffer layer. A method of making such a thin film semiconductor structure is also described.

  10. Mössbauer study of metallic iron and iron oxide nanoparticles having environmental purifying ability

    SciTech Connect (OSTI)

    Kubuki, Shiro, E-mail: kubuki@tmu.ac.jp; Watanabe, Yuka, E-mail: kubuki@tmu.ac.jp; Akiyama, Kazuhiko, E-mail: kubuki@tmu.ac.jp [Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachi-Oji, Tokyo 192-0397 (Japan); Risti?, Mira; Krehula, Stjepko [Division of Materials Chemistry, Ru?er Boškovi? Institute, P. O. Box 180, Zagreb 10002 (Croatia); Homonnay, Zoltán; Kuzmann, Ern? [Institute of Chemistry, Eötvös Loránd University, P.O. Box 32, 1512 Budapest (Hungary); Nishida, Tetsuaki [Department of Biological and Environmental Chemistry, Faculty of Humanity-Oriented Science and Engineering, Kinki University, 11-6 Kayanomori, Iizuka, Fukuoka 820-8555 (Japan)

    2014-10-27T23:59:59.000Z

    A relationship between local structure and methylene blue (MB) decomposing ability of nanoparticles (NPs) of metallic iron (Fe{sup 0}) and maghemite (??Fe{sub 2}O{sub 3}) was investigated by {sup 57}Fe Mössbauer spectroscopy, X-ray diffractometry and UV-visible light absorption spectroscopy. ??Fe{sub 2}O{sub 3} NPs were successfully prepared by mixing (NH{sub 4}){sub 2}Fe(SO{sub 4}){sub 2}?6H{sub 2}O (Mohr's salt) and (NH{sub 4}){sub 3}Fe(C{sub 2}O{sub 4}){sub 3}?3H{sub 2}O aqueous solution at 30 °C for 1 h, while those of Fe{sup 0} were obtained by the reduction of Mohr's salt with NaBH{sub 4}. From the Scherrer's equation, the smallest crystallite sizes of ??Fe{sub 2}O{sub 3} NPs and Fe{sup 0} NPs were determined to be 9.7 and 1.5 nm, respectively. {sup 57}Fe Mössbauer spectrum of ??Fe{sub 2}O{sub 3} NPs consists of a relaxed sextet with isomer shift (?) of 0.33{sub ±0.01} mm s{sup ?1}, internal magnetic field (H{sub int}) of 25.8{sub ±0.5} T, and linewidth (?) of 0.62{sub ±0.04} mm s{sup ?1}. {sup 57}Fe Mössbauer spectrum of Fe{sup 0} NP is mainly composed of a sextet having ?, ?, and H{sub int} of 0.00{sub ±0.01} mm s{sup ?1} 0.45{sub ±0.01} mm s{sup ?1}, and 22.8{sub ±0.1} T, respectively. A bleaching test of the mixture of Fe{sup 0} and ??Fe{sub 2}O{sub 3} NPs (3:7 ratio, 100 mg) in MB aqueous solution (20 mL) for 6 h showed a remarkable decrease of MB concentration with the first-order rate constant (k{sub MB}) of 6.7 × 10{sup ?1} h{sup ?1}. This value is larger than that obtained for the bleaching test using bulk Fe{sup 0}+??Fe{sub 2}O{sub 3} (3:7) mixture (k{sub MB}?=?6.5×10{sup ?3}h{sup ?1}). These results prove that MB decomposing ability is enhanced by the NPs mixture of Fe{sub 0} and ??Fe{sub 2}O{sub 3}.

  11. Invited paper History of Semiconductors

    E-Print Network [OSTI]

    Lidia ?ukasiak; Andrzej Jakubowski

    Abstract—The history of semiconductors is presented beginning with the first documented observation of a semiconductor effect (Faraday), through the development of the first devices (point-contact rectifiers and transistors, early field-effect transistors) and the theory of semiconductors up to the contemporary devices (SOI and multigate devices). Keywords—band theory, laser, Moore’s law, semiconductor, transistor.

  12. Liquid crystal terahertz phase shifters with functional indium-tin-oxide nanostructures for biasing and alignment

    SciTech Connect (OSTI)

    Yang, Chan-Shan [Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Tang, Tsung-Ta [Taiwan Semiconductor Manufacturing Company, Hsinchu, Taiwan (China); Pan, Ru-Pin [Department of Electrophysics, National Chiao Tung University, Hsinchu 30078, Taiwan (China); Yu, Peichen [Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan (China); Pan, Ci-Ling, E-mail: clpan@phys.nthu.edu.tw [Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Frontier Research Center on Fundamental and Applied Science of Matters, Hsinchu 30013, Taiwan (China)

    2014-04-07T23:59:59.000Z

    Indium Tin Oxide (ITO) nanowhiskers (NWhs) obliquely evaporated by electron-beam glancing-angle deposition can serve simultaneously as transparent electrodes and alignment layer for liquid crystal (LC) devices in the terahertz (THz) frequency range. To demonstrate, we constructed a THz LC phase shifter with ITO NWhs. Phase shift exceeding ?/2 at 1.0 THz was achieved in a ?517??m-thick cell. The phase shifter exhibits high transmittance (?78%). The driving voltage required for quarter-wave operation is as low as 5.66?V (rms), compatible with complementary metal-oxide-semiconductor (CMOS) and thin-film transistor (TFT) technologies.

  13. Phosphorous doping a semiconductor particle

    DOE Patents [OSTI]

    Stevens, Gary Don (18912 Ravenglen Ct, Dallas, TX 75287); Reynolds, Jeffrey Scott (703 Horizon, Murphy, TX 75094)

    1999-07-20T23:59:59.000Z

    A method (10) of phosphorus doping a semiconductor particle using ammonium phosphate. A p-doped silicon sphere is mixed with a diluted solution of ammonium phosphate having a predetermined concentration. These spheres are dried (16, 18), with the phosphorus then being diffused (20) into the sphere to create either a shallow or deep p-n junction. A good PSG glass layer is formed on the surface of the sphere during the diffusion process. A subsequent segregation anneal process is utilized to strip metal impurities from near the p-n junction into the glass layer. A subsequent HF strip procedure is then utilized to removed the PSG layer. Ammonium phosphate is not a restricted chemical, is inexpensive, and does not pose any special shipping, handling, or disposal requirement.

  14. Thermal Conductivity of Polycrystalline Semiconductors and Ceramics

    E-Print Network [OSTI]

    Wang, Zhaojie

    2012-01-01T23:59:59.000Z

    semiconductors and ceramics with desired thermalthermal conductivity of several polycrystalline semiconductors and ceramics,Thermal Conductivity of Polycrystalline Semiconductors and Ceramics

  15. Alleviation of fermi-level pinning effect at metal/germanium interface by the insertion of graphene layers

    SciTech Connect (OSTI)

    Baek, Seung-heon Chris; Seo, Yu-Jin; Oh, Joong Gun; Albert Park, Min Gyu; Bong, Jae Hoon; Yoon, Seong Jun; Lee, Seok-Hee, E-mail: seokheelee@ee.kaist.ac.kr [Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Seo, Minsu; Park, Seung-young [Division of Materials Science, Korea Basic Science Institute (KBSI), 169-148 Daehak-ro, Yuseong-gu, Daejeon 305-333 (Korea, Republic of); Park, Byong-Guk [Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

    2014-08-18T23:59:59.000Z

    In this paper, we report the alleviation of the Fermi-level pinning on metal/n-germanium (Ge) contact by the insertion of multiple layers of single-layer graphene (SLG) at the metal/n-Ge interface. A decrease in the Schottky barrier height with an increase in the number of inserted SLG layers was observed, which supports the contention that Fermi-level pinning at metal/n-Ge contact originates from the metal-induced gap states at the metal/n-Ge interface. The modulation of Schottky barrier height by varying the number of inserted SLG layers (m) can bring about the use of Ge as the next-generation complementary metal-oxide-semiconductor material. Furthermore, the inserted SLG layers can be used as the tunnel barrier for spin injection into Ge substrate for spin-based transistors.

  16. Influence of surface defects and local structure on acid/base properties and oxidation pathways over metal oxide surfaces. Final report, June 1990--January 1997

    SciTech Connect (OSTI)

    Cox, D.F.

    1997-12-31T23:59:59.000Z

    This final report covers work done during project period one and project period two. All the work in project period one was focused on the selective oxidation of oxygenated hydrocarbons over the SnO{sub 2}(110) single crystal surface. In project period two, the emphasis was on the acid/base properties of SnO{sub 2}(110) as well as two different Cu{sub 2}O single crystal surfaces. Prior to the summary of results, a description of these different surfaces is given as background information. Results are described for the dissociation and reaction of Bronsted acids (methanol, formic acid, water, formaldehyde, acetone, propene, acetic acid, and carbon monoxide). Results from project period two include: ammonia adsorption, CO{sub 2} adsorption, propene adsorption and oxidation, with tin oxides; complimentary work with copper oxides; and STM investigations.

  17. In situ X-ray absorption fine structure studies of foreign metal ions in nickel hydrous oxide electrodes in alkaline electrolytes

    SciTech Connect (OSTI)

    Kim, Sunghyun; Tryk, D.A.; Scherson, D. (Case Western Reserve Univ., Cleveland, OH (United States)); Antonio, M.R. (Argonne National Lab., IL (United States)); Carr, R. (Stanford Synchrotron Radiation Lab., CA (United States))

    1994-10-06T23:59:59.000Z

    Aspects of the structural and electronic properties of hydrous oxide films of composite (9:1) Ni/Co and (9:1) Ni/Fe, prepared by electrodeposition, have been examined in alkaline electrolytes using in situ X-ray absorption fine structure (XAFS). An analysis of the X-ray absorption near the edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) for the Co and Fe K-edges of these composite hydrous oxides revealed that, regardless of the oxidation state of nickel sites in the films, the guest metal ions are present as Co[sup 3+] and Fe[sup 3+] and that the cobalt-oxygen distance d(Co-O) = 1.9 [+-] 0.02 [angstrom] and d(Fe-O) = 1.92 [+-] 0.02 [angstrom]. The latter values are in excellent agreement with d(Me-O) (Me = Co or Fe) in CoOOH and [beta]- and [gamma]-FeOOH, respectively, determined by conventional X-ray diffraction. Two clearly defined Me-Ni first coordination shells could be observed in the Fourier transforms (FT) of the K-edge EXAFS of the guest metal recorded at a potential at which both Ni[sup 2+] and Ni[sup 3+] sites are expected to be present. 28 refs., 10 figs., 3 tabs.

  18. Adsorption of propane, isopropyl, and hydrogen on cluster models of the M1 phase of Mo-V-Te-Nb-O mixed metal oxide catalyst

    SciTech Connect (OSTI)

    Govindasamy, Agalya [University of Cincinnati; Muthukumar, Kaliappan [University of Cincinnati; Yu, Junjun [University of Cincinnati; Xu, Ye [ORNL; Guliants, Vadim V. [University of Cincinnati

    2010-01-01T23:59:59.000Z

    The Mo-V-Te-Nb-O mixed metal oxide catalyst possessing the M1 phase structure is uniquely capable of directly converting propane into acrylonitrile. However, the mechanism of this complex eight-electron transformation, which includes a series of oxidative H-abstraction and N-insertion steps, remains poorly understood. We have conducted a density functional theory study of cluster models of the proposed active and selective site for propane ammoxidation, including the adsorption of propane, isopropyl (CH{sub 3}CHCH{sub 3}), and H which are involved in the first step of this transformation, that is, the methylene C-H bond scission in propane, on these active site models. Among the surface oxygen species, the telluryl oxo (Te=O) is found to be the most nucleophilic. Whereas the adsorption of propane is weak regardless of the MO{sub x} species involved, isopropyl and H adsorption exhibits strong preference in the order of Te=O > V=O > bridging oxygens > empty Mo apical site, suggesting the importance of TeO{sub x} species for H abstraction. The adsorption energies of isopropyl and H and consequently the reaction energy of the initial dehydrogenation of propane are strongly dependent on the number of ab planes included in the cluster, which points to the need to employ multilayer cluster models to correctly capture the energetics of surface chemistry on this mixed metal oxide catalyst.

  19. Durable metallized polymer mirror

    DOE Patents [OSTI]

    Schissel, Paul O. (Golden, CO); Kennedy, Cheryl E. (Lafayette, CO); Jorgensen, Gary J. (Pine, CO); Shinton, Yvonne D. (Northglenn, CO); Goggin, Rita M. (Englewood, CO)

    1994-01-01T23:59:59.000Z

    A metallized polymer mirror construction having improved durability against delamination and tunneling, comprising: an outer layer of polymeric material; a metal oxide layer underlying the outer layer of polymeric material; a silver reflective layer underneath the metal oxide layer; and a layer of adhesive attaching the silver layer to a substrate.

  20. Durable metallized polymer mirror

    DOE Patents [OSTI]

    Schissel, P.O.; Kennedy, C.E.; Jorgensen, G.J.; Shinton, Y.D.; Goggin, R.M.

    1994-11-01T23:59:59.000Z

    A metallized polymer mirror construction is disclosed having improved durability against delamination and tunneling, comprising: an outer layer of polymeric material; a metal oxide layer underlying the outer layer of polymeric material; a silver reflective layer underneath the metal oxide layer; and a layer of adhesive attaching the silver layer to a substrate. 6 figs.

  1. Actinide metal processing

    DOE Patents [OSTI]

    Sauer, Nancy N. (Los Alamos, NM); Watkin, John G. (Los Alamos, NM)

    1992-01-01T23:59:59.000Z

    A process of converting an actinide metal such as thorium, uranium, or plnium to an actinide oxide material by admixing the actinide metal in an aqueous medium with a hypochlorite as an oxidizing agent for sufficient time to form the actinide oxide material and recovering the actinide oxide material is provided together with a low temperature process of preparing an actinide oxide nitrate such as uranyl nitrte. Additionally, a composition of matter comprising the reaction product of uranium metal and sodium hypochlorite is provided, the reaction product being an essentially insoluble uranium oxide material suitable for disposal or long term storage.

  2. Actinide metal processing

    DOE Patents [OSTI]

    Sauer, N.N.; Watkin, J.G.

    1992-03-24T23:59:59.000Z

    A process for converting an actinide metal such as thorium, uranium, or plutonium to an actinide oxide material by admixing the actinide metal in an aqueous medium with a hypochlorite as an oxidizing agent for sufficient time to form the actinide oxide material and recovering the actinide oxide material is described together with a low temperature process for preparing an actinide oxide nitrate such as uranyl nitrate. Additionally, a composition of matter comprising the reaction product of uranium metal and sodium hypochlorite is provided, the reaction product being an essentially insoluble uranium oxide material suitable for disposal or long term storage.

  3. Reducible oxide based catalysts

    DOE Patents [OSTI]

    Thompson, Levi T.; Kim, Chang Hwan; Bej, Shyamal K.

    2010-04-06T23:59:59.000Z

    A catalyst is disclosed herein. The catalyst includes a reducible oxide support and at least one noble metal fixed on the reducible oxide support. The noble metal(s) is loaded on the support at a substantially constant temperature and pH.

  4. Hybrid structure laser based on semiconductor nanowires and a silica microfiber knot cavity

    E-Print Network [OSTI]

    Wu, Shin-Tson

    Hybrid structure laser based on semiconductor nanowires and a silica microfiber knot cavity Qing://apl.aip.org/about/rights_and_permissions #12;Hybrid structure laser based on semiconductor nanowires and a silica microfiber knot cavity Qing 2009 We demonstrate a hybrid structure laser consisting of a single or multiple zinc oxide Zn

  5. Method for synthesis of high T[sub c] superconducting materials by oxidation and press coating of metallic precursor alloys

    DOE Patents [OSTI]

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

    1993-01-19T23:59:59.000Z

    A superconductor oxide composite is prepared using a press coating technique. The coated layers on various substrates exhibit good adhesion, textured microstructure, and improved J[sub c].

  6. Nickel-and Ruthenium-Doped Lanthanum Chromite Anodes: Effects of Nanoscale Metal Precipitation on Solid Oxide

    E-Print Network [OSTI]

    Marks, Laurence D.

    on Solid Oxide Fuel Cell Performance W. Kobsiriphat,* B. D. Madsen, Y. Wang, M. Shah, L. D. Marks, and S. A characterization and electrochemical measurements in solid oxide fuel cells SOFCs . Transmission electron electrochemical kinetics. © 2009 The Electrochemical Society. DOI: 10.1149/1.3269993 All rights reserved

  7. Kansas Advanced Semiconductor Project

    SciTech Connect (OSTI)

    Baringer, P.; Bean, A.; Bolton, T.; Horton-Smith, G.; Maravin, Y.; Ratra, B.; Stanton, N.; von Toerne, E.; Wilson, G.

    2007-09-21T23:59:59.000Z

    KASP (Kansas Advanced Semiconductor Project) completed the new Layer 0 upgrade for D0, assumed key electronics projects for the US CMS project, finished important new physics measurements with the D0 experiment at Fermilab, made substantial contributions to detector studies for the proposed e+e- international linear collider (ILC), and advanced key initiatives in non-accelerator-based neutrino physics.

  8. The Fundamental Role of Nano-Scale Oxide Films in the Oxidation of Hydrogen and the Reduction of Oxygen on Noble Metal Electrocatalysts

    SciTech Connect (OSTI)

    Digby Macdonald

    2005-04-15T23:59:59.000Z

    The derivation of successful fuel cell technologies requires the development of more effective, cheaper, and poison-resistant electrocatalysts for both the anode (H{sub 2} oxidation in the presence of small amounts of CO from the reforming of carbonaceous fuels) and the cathode (reduction of oxygen in the presence of carried-over fuel). The proposed work is tightly focused on one specific aspect of electrocatalysis; the fundamental role(s) played by nanoscale (1-2 nm thick) oxide (''passive'') films that form on the electrocatalyst surfaces above substrate-dependent, critical potentials, on charge transfer reactions, particularly at elevated temperatures (25 C < T < 200 C). Once the role(s) of these films is (are) adequately understood, we will then use this information to specify, at the molecular level, optimal properties of the passive layer for the efficient electrocatalysis of the oxygen reduction reaction.

  9. Photoluminescence quenching of tris-(8-hydroxyquinoline) aluminum thin films at interfaces with metal oxide films of different conductivities

    E-Print Network [OSTI]

    Mei, Jun

    We report a comprehensive study of photoluminescence (PL) quenching of tris-(8-hydroxyquinoline) aluminum (Alq[subscript ]3) at interfaces with thin films of tin oxide (SnO[subscript 2]) using both steady-state and ...

  10. Dielectric function of diluted magnetic semiconductors in the infrared regime

    E-Print Network [OSTI]

    Aguado, R.; Lopez-Sancho, MP; Sinova, Jairo; Brey, L.

    2004-01-01T23:59:59.000Z

    We present a study of the dielectric function of metallic (III,Mn)V diluted magnetic semiconductors in the infrared regime. Our theoretical approach is based on the kinetic exchange model for carrier induced (III,Mn)V ferromagnetism. The dielectric...

  11. Method and system for the combination of non-thermal plasma and metal/metal oxide doped .gamma.-alumina catalysts for diesel engine exhaust aftertreatment system

    DOE Patents [OSTI]

    Aardahl, Christopher L. (Richland, WA); Balmer-Miller, Mari Lou (West Richland, WA); Chanda, Ashok (Peoria, IL); Habeger, Craig F. (West Richland, WA); Koshkarian, Kent A. (Peoria, IL); Park, Paul W. (Peoria, IL)

    2006-07-25T23:59:59.000Z

    The present disclosure pertains to a system and method for treatment of oxygen rich exhaust and more specifically to a method and system that combines non-thermal plasma with a metal doped .gamma.-alumina catalyst. Current catalyst systems for the treatment of oxygen rich exhaust are capable of achieving only approximately 7 to 12% NO.sub.x reduction as a passive system and only 25 40% reduction when a supplemental hydrocarbon reductant is injected into the exhaust stream. It has been found that treatment of an oxygen rich exhaust initially with a non-thermal plasma and followed by subsequent treatment with a metal doped .gamma.-alumina prepared by the sol gel method is capable of increasing the NO.sub.x reduction to a level of approximately 90% in the absence of SO.sub.2 and 80% in the presence of 20 ppm of SO.sub.2. Especially useful metals have been found to be indium, gallium, and tin.

  12. Charge transport mechanisms of graphene/semiconductor Schottky barriers: A theoretical and experimental study

    SciTech Connect (OSTI)

    Zhong, Haijian; Liu, Zhenghui; Xu, Gengzhao; Shi, Lin; Fan, Yingmin; Yang, Hui [Suzhou Institute of Nano-Tech and Nano-Bionics, CAS, Suzhou 215123 (China); Xu, Ke, E-mail: kxu2006@sinano.ac.cn; Wang, Jianfeng; Ren, Guoqiang [Suzhou Institute of Nano-Tech and Nano-Bionics, CAS, Suzhou 215123 (China); Suzhou Nanowin Science and Technology Co., Ltd., Suzhou 215123 (China)

    2014-01-07T23:59:59.000Z

    Graphene has been proposed as a material for semiconductor electronic and optoelectronic devices. Understanding the charge transport mechanisms of graphene/semiconductor Schottky barriers will be crucial for future applications. Here, we report a theoretical model to describe the transport mechanisms at the interface of graphene and semiconductors based on conventional semiconductor Schottky theory and a floating Fermi level of graphene. The contact barrier heights can be estimated through this model and be close to the values obtained from the experiments, which are lower than those of the metal/semiconductor contacts. A detailed analysis reveals that the barrier heights are as the function of the interface separations and dielectric constants, and are influenced by the interfacial states of semiconductors. Our calculations show how this behavior of lowering barrier heights arises from the Fermi level shift of graphene induced by the charge transfer owing to the unique linear electronic structure.

  13. Coated semiconductor devices for neutron detection

    DOE Patents [OSTI]

    Klann, Raymond T. (Bolingbrook, IL); McGregor, Douglas S. (Whitmore Lake, MI)

    2002-01-01T23:59:59.000Z

    A device for detecting neutrons includes a semi-insulated bulk semiconductor substrate having opposed polished surfaces. A blocking Schottky contact comprised of a series of metals such as Ti, Pt, Au, Ge, Pd, and Ni is formed on a first polished surface of the semiconductor substrate, while a low resistivity ("ohmic") contact comprised of metals such as Au, Ge, and Ni is formed on a second, opposed polished surface of the substrate. In one embodiment, n-type low resistivity pinout contacts comprised of an Au/Ge based eutectic alloy or multi-layered Pd/Ge/Ti/Au are also formed on the opposed polished surfaces and in contact with the Schottky and ohmic contacts. Disposed on the Schottky contact is a neutron reactive film, or coating, for detecting neutrons. The coating is comprised of a hydrogen rich polymer, such as a polyolefin or paraffin; lithium or lithium fluoride; or a heavy metal fissionable material. By varying the coating thickness and electrical settings, neutrons at specific energies can be detected. The coated neutron detector is capable of performing real-time neutron radiography in high gamma fields, digital fast neutron radiography, fissile material identification, and basic neutron detection particularly in high radiation fields.

  14. Method for preparing metal powder, device for preparing metal powder, method for processing spent nuclear fuel

    DOE Patents [OSTI]

    Park, Jong-Hee (Clarendon Hills, IL)

    2011-11-29T23:59:59.000Z

    A method for producing metal powder is provided the comprising supplying a molten bath containing a reducing agent, contacting a metal oxide with the molten bath for a time and at a temperature sufficient to reduce the metal in the metal oxide to elemental metal and produce free oxygen; and isolating the elemental metal from the molten bath.

  15. Semiconductor radiation detector

    DOE Patents [OSTI]

    Patt, Bradley E. (Sherman Oaks, CA); Iwanczyk, Jan S. (Los Angeles, CA); Tull, Carolyn R. (Orinda, CA); Vilkelis, Gintas (Westlake Village, CA)

    2002-01-01T23:59:59.000Z

    A semiconductor radiation detector is provided to detect x-ray and light photons. The entrance electrode is segmented by using variable doping concentrations. Further, the entrance electrode is physically segmented by inserting n+ regions between p+ regions. The p+ regions and the n+ regions are individually biased. The detector elements can be used in an array, and the p+ regions and the n+ regions can be biased by applying potential at a single point. The back side of the semiconductor radiation detector has an n+ anode for collecting created charges and a number of p+ cathodes. Biased n+ inserts can be placed between the p+ cathodes, and an internal resistor divider can be used to bias the n+ inserts as well as the p+ cathodes. A polysilicon spiral guard can be implemented surrounding the active area of the entrance electrode or surrounding an array of entrance electrodes.

  16. Thin Film Solid-State Reactions Forming Carbides as Contact Materials for Carbon-Containing Semiconductors

    SciTech Connect (OSTI)

    Leroy,W.; Detavernier, C.; Van Meirhaeghe, R.; Lavoie, C.

    2007-01-01T23:59:59.000Z

    Metal carbides are good candidates to contact carbon-based semiconductors (SiC, diamond, and carbon nanotubes). Here, we report on an in situ study of carbide formation during the solid-state reaction between thin films. The solid-state reaction was examined between 11 transition metals (W, Mo, Fe, Cr, V, Nb, Mn, Ti, Ta, Zr, and Hf) and an amorphous carbon layer. Capping layers (C or TiN) of different thicknesses were applied to prevent oxidation. Carbide formation is evidenced for nine metals and the phases formed have been identified (for a temperature ranging from 100 to 1100 C). W first forms W{sub 2}C and then WC; Mo forms Mo{sub 2}C; Fe forms Fe{sub 3}C; Cr first forms metastable phases Cr{sub 2}C and Cr{sub 3}C{sub 2-x}, and finally forms Cr{sub 3}C{sub 2}; V forms VC{sub x}; Nb transforms into Nb{sub 2}C followed by NbC; Ti forms TiC; Ta first forms Ta{sub 2}C and then TaC; and Hf transforms into HfC. The activation energy for the formation of the various carbide phases has been obtained by in situ x-ray diffraction.

  17. Semiconductor Ion Implanters

    SciTech Connect (OSTI)

    MacKinnon, Barry A. [Isys, 2727 Walsh Ave., Suite 103, Santa Clara, CA 95051 (United States); Ruffell, John P. [Group 3, LLC, Sunnyvale, CA 94086 (United States)

    2011-06-01T23:59:59.000Z

    In 1953 the Raytheon CK722 transistor was priced at $7.60. Based upon this, an Intel Xeon Quad Core processor containing 820,000,000 transistors should list at $6.2 billion. Particle accelerator technology plays an important part in the remarkable story of why that Intel product can be purchased today for a few hundred dollars. Most people of the mid twentieth century would be astonished at the ubiquity of semiconductors in the products we now buy and use every day. Though relatively expensive in the nineteen fifties they now exist in a wide range of items from high-end multicore microprocessors like the Intel product to disposable items containing 'only' hundreds or thousands like RFID chips and talking greeting cards. This historical development has been fueled by continuous advancement of the several individual technologies involved in the production of semiconductor devices including Ion Implantation and the charged particle beamlines at the heart of implant machines. In the course of its 40 year development, the worldwide implanter industry has reached annual sales levels around $2B, installed thousands of dedicated machines and directly employs thousands of workers. It represents in all these measures, as much and possibly more than any other industrial application of particle accelerator technology. This presentation discusses the history of implanter development. It touches on some of the people involved and on some of the developmental changes and challenges imposed as the requirements of the semiconductor industry evolved.

  18. EUREM 12, Brno, Czech Republic, July 9-14, 2000 I 159 Super Resolution Imaging of Complex Metal Oxides

    E-Print Network [OSTI]

    Dunin-Borkowski, Rafal E.

    rather than the image intensity that is recorded by conventional HREM. In this paper, restorations that have been investigated are Nb16W18O94, which consists of pentagonal columns of metal cations projected, samples were prepared by crushing and dispersion of the raw material onto a holey carbon support film

  19. Single-Site Vanadyl Activation, Functionalization, and Reoxidation Reaction Mechanism for Propane Oxidative Dehydrogenation on the Cubic V4O10 Cluster

    E-Print Network [OSTI]

    Goddard III, William A.

    , and mixed metal oxide (MMO) catalysts for selective oxidation and ammoxida- tion of propene to acrolein

  20. Method of passivating semiconductor surfaces

    DOE Patents [OSTI]

    Wanlass, Mark W. (Golden, CO)

    1990-01-01T23:59:59.000Z

    A method of passivating Group III-V or II-VI semiconductor compound surfaces. The method includes selecting a passivating material having a lattice constant substantially mismatched to the lattice constant of the semiconductor compound. The passivating material is then grown as an ultrathin layer of passivating material on the surface of the Group III-V or II-VI semiconductor compound. The passivating material is grown to a thickness sufficient to maintain a coherent interface between the ultrathin passivating material and the semiconductor compound. In addition, a device formed from such method is also disclosed.

  1. Method of passivating semiconductor surfaces

    SciTech Connect (OSTI)

    Wanlass, M.W.

    1990-06-19T23:59:59.000Z

    A method is described for passivating Group III-V or II-VI semiconductor compound surfaces. The method includes selecting a passivating material having a lattice constant substantially mismatched to the lattice constant of the semiconductor compound. The passivating material is then grown as an ultrathin layer of passivating material on the surface of the Group III-V or II-VI semiconductor compound. The passivating material is grown to a thickness sufficient to maintain a coherent interface between the ultrathin passivating material and the semiconductor compound. In addition, a device formed from such method is also disclosed.

  2. “Covalent Hydration” Reactions in Model Monomeric Ru 2,2'-Bipyridine Complexes: Thermodynamic Favorability as a Function of Metal Oxidation and Overall Spin States

    SciTech Connect (OSTI)

    Ozkanlar, Abdullah; Cape, Jonathan L.; Hurst, James K.; Clark, Aurora E.

    2011-09-05T23:59:59.000Z

    Density functional theory (DFT) has been used to investigate the plausibility of water addition to the simple mononuclear ruthenium complexes, [(NH{sub 3}){sub 3}(bpy)Ru=O]{sup 2+}/{sup 3+} and [(NH{sub 3}){sub 3}(bpy)RuOH]{sup 3+}, in which the OH fragment adds to the 2,2{prime}-bipyridine (bpy) ligand. Activation of bpy toward water addition has frequently been postulated within the literature, although there exists little definitive experimental evidence for this type of 'covalent hydration'. In this study, we examine the energetic dependence of the reaction upon metal oxidation state, overall spin state of the complex, as well as selectivity for various positions on the bipyridine ring. The thermodynamic favorability is found to be highly dependent upon all three parameters, with free energies of reaction that span favorable and unfavorable regimes. Aqueous addition to [(NH{sub 3}){sub 3}(bpy)Ru=O]{sup 3+} was found to be highly favorable for the S = 1/2 state, while reduction of the formal oxidation state on the metal center makes the reaction highly unfavorable. Examination of both facial and meridional isomers reveals that when bipyridine occupies the position trans to the ruthenyl oxo atom, reactivity toward OH addition decreases and the site preferences are altered. The electronic structure and spectroscopic signatures (EPR parameters and simulated spectra) have been determined to aid in recognition of 'covalent hydration' in experimental systems. EPR parameters are found to uniquely characterize the position of the OH addition to the bpy as well as the overall spin state of the system.

  3. Noise and synamics in semiconductor lasers

    E-Print Network [OSTI]

    Rana, Farhan, 1971-

    2003-01-01T23:59:59.000Z

    In this thesis, theoretical and experimental work on the noise and dynamics in continuous wave and mode-locked semiconductor lasers is presented. The main focus is on semiconductor cascade lasers and semiconductor mode-locked ...

  4. In situ Fourier transform infrared spectroscopy of adsorbed species on mixed metal oxide catalysts for higher alcohol synthesis

    SciTech Connect (OSTI)

    Baysar, A.

    1986-01-01T23:59:59.000Z

    Fourier Transform Infrared Spectroscopy was utilized to identify adsorbed species on Zn/Cu/Cr oxide and potassium carbonate-promoted Zn/Cu/Cr oxide catalysts at 285/sup 0/C and atmospheric pressure. Adsorption of various molecules on catalysts provided information about the nature of the adsorbed species. As a result of CO/H/sub 2/ mixture, methanol and formaldehyde adsorption two types of species formed, namely a methoxy and a formate. The adsorption of ethanol, acetaldehyde and acetic acid at 285/sup 0/C revealed stable acetate species. Ethanol and acetaldehyde adsorption also produced an ethoxy species whose formation was much favored on promoted catalysts. 136 refs., 46 figs., 14 tabs.

  5. Layered semiconductor neutron detectors

    DOE Patents [OSTI]

    Mao, Samuel S; Perry, Dale L

    2013-12-10T23:59:59.000Z

    Room temperature operating solid state hand held neutron detectors integrate one or more relatively thin layers of a high neutron interaction cross-section element or materials with semiconductor detectors. The high neutron interaction cross-section element (e.g., Gd, B or Li) or materials comprising at least one high neutron interaction cross-section element can be in the form of unstructured layers or micro- or nano-structured arrays. Such architecture provides high efficiency neutron detector devices by capturing substantially more carriers produced from high energy .alpha.-particles or .gamma.-photons generated by neutron interaction.

  6. Avalanche semiconductor radiation detectors

    SciTech Connect (OSTI)

    Sadygov, Z.Y. [Joint Inst. for Nuclear Research, Dubna (Russian Federation)] [Joint Inst. for Nuclear Research, Dubna (Russian Federation); [Azerbaijan Academy of Sciences, Baku (Azerbaijan). Physics Inst.; Zheleznykh, I.M.; Kirillova, T.A. [Russian Academy of Sciences, Moscow (Russian Federation). Inst. for Nuclear Research] [Russian Academy of Sciences, Moscow (Russian Federation). Inst. for Nuclear Research; Malakhov, N.A.; Jejer, V.N. [Joint Inst. for Nuclear Research, Dubna (Russian Federation)] [Joint Inst. for Nuclear Research, Dubna (Russian Federation)

    1996-06-01T23:59:59.000Z

    Operation of novel avalanche semiconductor detector, produced on the basis of heterojunctions Si-SiC and Si-Si{sub x}O{sub y} is described. A uniform avalanche process with gain from 10{sup 3} to 10{sup 5} can be reached depending on the conductivity of SiC and Si{sub x}O{sub y} layers. Two types of avalanche photodetectors designed for applications in wavelength range 500--10,00 nm with quantum efficiency 60 {+-} 10% (650 nm) and 200--700 nm with quantum efficiency 60 {+-} 15% (450 nm) are presented.

  7. Efficient semiconductor light-emitting device and method

    DOE Patents [OSTI]

    Choquette, Kent D. (Albuquerque, NM); Lear, Kevin L. (Albuquerque, NM); Schneider, Jr., Richard P. (Albuquerque, NM)

    1996-01-01T23:59:59.000Z

    A semiconductor light-emitting device and method. The semiconductor light-emitting device is provided with at least one control layer or control region which includes an annular oxidized portion thereof to channel an injection current into the active region, and to provide a lateral refractive index profile for index guiding the light generated within the device. A periodic composition grading of at least one of the mirror stacks in the device provides a reduced operating voltage of the device. The semiconductor light-emitting device has a high efficiency for light generation, and may be formed either as a resonant-cavity light-emitting diode (RCLED) or as a vertical-cavity surface-emitting laser (VCSEL).

  8. Efficient semiconductor light-emitting device and method

    DOE Patents [OSTI]

    Choquette, K.D.; Lear, K.L.; Schneider, R.P. Jr.

    1996-02-20T23:59:59.000Z

    A semiconductor light-emitting device and method are disclosed. The semiconductor light-emitting device is provided with at least one control layer or control region which includes an annular oxidized portion thereof to channel an injection current into the active region, and to provide a lateral refractive index profile for index guiding the light generated within the device. A periodic composition grading of at least one of the mirror stacks in the device provides a reduced operating voltage of the device. The semiconductor light-emitting device has a high efficiency for light generation, and may be formed either as a resonant-cavity light-emitting diode (RCLED) or as a vertical-cavity surface-emitting laser (VCSEL). 12 figs.

  9. CO Oxidation on Pt-Group Metals from Ultrahigh Vacuum to Near Atmospheric Pressures. F. Gao, Y. Cai, K. K. Gath, Y. Wang, M. S. Chen, Q. L. Guo, and D. W. Goodman*

    E-Print Network [OSTI]

    Goodman, Wayne

    polarization modulation infrared reflection absorption spectroscopy (PM-IRAS) and X-ray photoelectronCO Oxidation on Pt-Group Metals from Ultrahigh Vacuum to Near Atmospheric Pressures. 1. Rhodium F. 6 found for a Pt(111) catalyst near atmospheric conditions, the reaction rate is linearly

  10. Synthesis of nanostructured materials in supercritical ammonia: nitrides, metals and oxides Desmoulins-Krawiec S., Aymonier C., Loppinet-Serani A., Weill F., Grosse S., Etourneau J., Cansell F.

    E-Print Network [OSTI]

    Boyer, Edmond

    N in supercritical cryogenic nitrogen by self-propagating-high- temperature synthesis (6.21 MPa, ­141 °C);19 (ii) GaSynthesis of nanostructured materials in supercritical ammonia: nitrides, metals and oxides. Abstract : In this study, the synthesis of nanostructured particles of nitrides (Cr2N, Co2N, Fe4N, Cu3N, Ni

  11. Photoexcited Individual Nanowires: Key Elements in Room Temperature Detection of Oxidizing Gases

    SciTech Connect (OSTI)

    Prades, J. D.; Jimenez-Diaz, R.; Manzanares, M.; Andreu, T.; Cirera, A.; Romano-Rodriguez, A. [EME/XaRMAE/IN2 UB, Dept. Electronica, Universitat de Barcelona, C/Marti i Franques 1, E-08028 Barcelona Spain (Spain); Hernandez-Ramirez, F. [Electronic Nanosystems S. L., Barcelona (Spain); Morante, J. R. [EME/XaRMAE/IN2 UB, Dept. Electronica, Universitat de Barcelona, C/Marti i Franques 1, E-08028 Barcelona Spain (Spain); Institut de Recerca en Energia de Catalunya (IREC), C/Josep Pla 2, B3, PB, E-08019 Barcelona (Spain)

    2009-05-23T23:59:59.000Z

    Illuminating metal oxide semiconductors with ultra-violet light is a feasible alternative to activate chemical reactions at their surface and thus, using them as gas sensors without the necessity of heating them. Here, the response at room temperature of individual single-crystalline SnO{sub 2} nanowires towards NO{sub 2} is studied in detail. The results reveal that similar responses to those obtained with thermally activated sensors can be achieved by choosing the optimal illumination conditions. This finding paves the way to the development of conductometric gas sensors operated at room temperature. The power consumption in these devices is in range with conventional micromachined sensors.

  12. Optoelectronic cooling of mechanical modes in a semiconductor nanomembrane

    E-Print Network [OSTI]

    K. Usami; A. Naesby; T. Bagci; B. Melholt Nielsen; J. Liu; S. Stobbe; P. Lodahl; E. S. Polzik

    2010-11-22T23:59:59.000Z

    Optical cavity cooling of mechanical resonators has recently become a research frontier. The cooling has been realized with a metal-coated silicon microlever via photo-thermal force and subsequently with dielectric objects via radiation pressure. Here we report cavity cooling with a crystalline semiconductor membrane via a new mechanism, in which the cooling force arises from the interaction between the photo-induced electron-hole pairs and the mechanical modes through the deformation potential coupling. The optoelectronic mechanism is so efficient as to cool a mode down to 4 K from room temperature with just 50 uW of light and a cavity with a finesse of 10 consisting of a standard mirror and the sub-wavelength-thick semiconductor membrane itself. The laser-cooled narrow-band phonon bath realized with semiconductor mechanical resonators may open up a new avenue for photonics and spintronics devices.

  13. Reactive codoping of GaAlInP compound semiconductors

    DOE Patents [OSTI]

    Hanna, Mark Cooper (Boulder, CO); Reedy, Robert (Golden, CO)

    2008-02-12T23:59:59.000Z

    A GaAlInP compound semiconductor and a method of producing a GaAlInP compound semiconductor are provided. The apparatus and method comprises a GaAs crystal substrate in a metal organic vapor deposition reactor. Al, Ga, In vapors are prepared by thermally decomposing organometallic compounds. P vapors are prepared by thermally decomposing phospine gas, group II vapors are prepared by thermally decomposing an organometallic group IIA or IIB compound. Group VIB vapors are prepared by thermally decomposing a gaseous compound of group VIB. The Al, Ga, In, P, group II, and group VIB vapors grow a GaAlInP crystal doped with group IIA or IIB and group VIB elements on the substrate wherein the group IIA or IIB and a group VIB vapors produced a codoped GaAlInP compound semiconductor with a group IIA or IIB element serving as a p-type dopant having low group II atomic diffusion.

  14. Comparative study of the reactions of metal oxides and carbonates with H{sub 2}S and SO{sub 2}. Final technical report, September 1990--February 1994

    SciTech Connect (OSTI)

    Sotirchos, S.V.

    1994-03-01T23:59:59.000Z

    The primary objective of this project had been the investigation of the effects of pore structure on the capacity of porous metal oxides for removal of gaseous pollutants from flue gases of power plants (SO{sub 2}) and hot coal gas (primarily H{sub 2}S). Porous calcines obtained from natural precursors (limestones and dolomites) and sorbents based on zinc oxide were used as model systems in our experimental studies, which included reactivity evolution experiments and pore structure characterization using a variety of methods. The key idea behind this project was to appropriately exploit the differences of the sulfidation and sulfation reactions (for instance, different molar volumes of solid products) to elucidate the dependence of the sorptive capacity of a porous sorbent on its physical microstructure. In order to be able to proceed faster and more productively on the analysis of the above defined problem, it was decided to employ in our studies solids whose reaction with SO{sub 2} (limestone calcines) or H{sub 2}S (sorbents based on zinc oxide) had been investigated in detail in past studies by our research group. Reactivity vs time or conversion vs time studies were conducted using thermogravimetry and fixed-bed and fluidized-bed reactors. The pore structure of partially reacted samples collected at selected time instants or conversion levels was analyzed by gas adsorption and mercury porosimetry. For better characterization of the pore structure of the solid samples, we also carried out intraparticle diffusivity measurements by the peak-broadening (chromatographic) method, using a system developed for this purpose in our laboratory. In the context of this part of the project, we also conducted a detailed theoretical investigation of the measurement of effective diffusivities in porous solids using the diffusion-cell method.

  15. Opportunities for Wide Bandgap Semiconductor Power Electronics...

    Energy Savers [EERE]

    Opportunities for Wide Bandgap Semiconductor Power Electronics for Hydrogen and Fuel Cell Applications Opportunities for Wide Bandgap Semiconductor Power Electronics for Hydrogen...

  16. Interaction of iron-copper mixed metal oxide oxygen carriers with simulated synthesis gas derived from steam gasification of coal

    SciTech Connect (OSTI)

    Siriwardane, Ranjani V. [U.S. DOE; Ksepko, Ewelina; Tian, Hanging [URS

    2013-01-01T23:59:59.000Z

    The objective of this work was to prepare supported bimetallic Fe–Cu oxygen carriers and to evaluate their performance for the chemical-looping combustion (CLC) process with simulated synthesis gas derived from steam gasification of coal/air. Ten-cycle CLC tests were conducted with Fe–Cu oxygen carriers in an atmospheric thermogravimetric analyzer utilizing simulated synthesis gas derived from the steam gasification of Polish Janina coal and Illinois #6 coal as fuel. The effect of temperature on reaction rates, chemical stability, and oxygen transport capacity were determined. Fractional reduction, fractional oxidation, and global rates of reactions were calculated from the thermogravimetric analysis (TGA) data. The supports greatly affected reaction performance. Data showed that reaction rates and oxygen capacities were stable during the 10-cycle TGA tests for most Fe–Cu/support oxygen carriers. Bimetallic Fe–Cu/support oxygen carriers showed higher reduction rates than Fe-support oxygen carriers. The carriers containing higher Cu content showed better stabilities and better reduction rates. An increase in temperature from 800 °C to 900 °C did not have a significant effect on either the oxygen capacity or the reduction rates with synthesis gas derived from Janina coal. Oxidation reaction was significantly faster than reduction reaction for all supported Fe–Cu oxygen carriers. Carriers with higher Cu content had lower oxidation rates. Ten-cycle TGA data indicated that these oxygen carriers had stable performances at 800–900 °C and might be successfully used up to 900 °C for coal CLC reaction in the presence of steam.

  17. Physics with isotopically controlled semiconductors

    SciTech Connect (OSTI)

    Haller, E. E., E-mail: eehaller@lbl.gov [University of California at Berkeley, Department of Materials Science and Engineering (United States)

    2010-07-15T23:59:59.000Z

    This paper is based on a tutorial presentation at the International Conference on Defects in Semiconductors (ICDS-25) held in Saint Petersburg, Russia in July 2009. The tutorial focused on a review of recent research involving isotopically controlled semiconductors. Studies with isotopically enriched semiconductor structures experienced a dramatic expansion at the end of the Cold War when significant quantities of enriched isotopes of elements forming semiconductors became available for worldwide collaborations. Isotopes of an element differ in nuclear mass, may have different nuclear spins and undergo different nuclear reactions. Among the latter, the capture of thermal neutrons which can lead to neutron transmutation doping, is the most prominent effect for semiconductors. Experimental and theoretical research exploiting the differences in all the properties has been conducted and will be illustrated with selected examples.

  18. Controlling the properties of bulk metal oxides at a molecular level: Alkoxides vs carboxylates-alkoxides routes

    SciTech Connect (OSTI)

    Hubert-Pfalzgraf, L.G.; Daniele, S.; Boulmaaz, S.; Papiernik, R. [Univ. de Nice Sophia-Antipolis, Nice (France)

    1994-12-31T23:59:59.000Z

    The reactions between alkoxides and/or alkoxides and anhydrous acetates have been investigated for access to advanced multicomponent niobates or titanates and with the aim to get insight into relationships between the nature of the initial precursors single or mixed metal derivatives, ligands (OAc or OR, R = Et, iPr),...- and the properties of the final material. Data are based on a variety of techniques: FT-IR, multinuclear NMR ({sup 1}H, {sup 13}C, {sup 207}Pb, {sup 113}Cd), X-ray investigations on single crystals. Powders have been analyzed by TGA, SEM-EDX, light scattering and XRD.

  19. LCD, low-temperature soldering and compound semiconductor : the sources, market, applications and future prospects of indium in Malaysia

    E-Print Network [OSTI]

    Yong, Foo Nun

    2006-01-01T23:59:59.000Z

    Indium is a minor but very valuable metal. Decreasing supplies of indium from refining and increasing demands from LCD, low-temperature soldering and compound semiconductors have stimulated the indium price increase ...

  20. Photoelectrochemistry in particulate systems. 7. Electron-transfer reactions of indium sulfide semiconductor colloids

    SciTech Connect (OSTI)

    Kamat, P.V.; Dimitrijevic, N.M.; Fessenden, R.W.

    1988-04-21T23:59:59.000Z

    Small semiconductor colloids of In/sub 2/S/sub 3/ have been prepared in aqueous and nonaqueous media and their absorption properties characterized. A transient photobleaching and formation of S/sup .-/ and S/sub 2/H/sub 2//sup .-/ radicals have been observed upon laser pulse (355 nm) excitation of these colloids. With the aid of transient absorption spectra, the anodic corrosion process in these semiconductor colloids has been elucidated by using laser flash photolysis and pulse radiolysis techniques. With the use of a zwitterionic viologen compound, the interfacial charge-transfer process at the semiconductor surface has been studied. The quantum yield for the reduction of zwitterionic viologen was 0.07, which is similar to the value obtained with other metal chalcogenide semiconductor colloids. The microenvironment of the stabilizer (Nafion) influenced the charge-transfer process between the semiconductor and the redox decay.

  1. Vapor phase modifiers for oxidative coupling

    DOE Patents [OSTI]

    Warren, Barbara K. (Charleston, WV)

    1991-01-01T23:59:59.000Z

    Volatilized metal compounds retard vapor phase alkane conversion reactions in oxidative coupling processes that convert lower alkanes to higher hydrocarbons.

  2. Single-Crystal Tungsten Oxide Nanosheets: Photochemical Water Oxidation in the Quantum Confinement Regime

    E-Print Network [OSTI]

    Osterloh, Frank

    Single-Crystal Tungsten Oxide Nanosheets: Photochemical Water Oxidation in the Quantum Confinement, catalysis, WO3, tungsten oxide, nanosheet, nanocrystal, quantum confinement, solar energy conversion INTRODUCTION Tungsten trioxide crystallizes in the ReO3 structure type and is an n-type semiconductor with a 2

  3. Electrodeposited doped II-VI semiconductor films and devices incorporating such films

    SciTech Connect (OSTI)

    Ondris, M.; Picher, M.A.; Brownfield, R.E.

    1990-03-20T23:59:59.000Z

    This patent describes a photovoltaic device. It comprises: a first thin film of a compound semiconductor of a first conductivity type including tellurium and a metal selected from Group IIB of the Periodic Table of Elements and containing as a dopant impurity in a concentration not exceeding 10{sup 20} atoms per cubic centimeter a metal selected from Group IB, a second semiconductor thin film in contact with the first semiconductor thin film and having a second conductivity type opposite that of the first conductivity type and electrical contacts to each of the first and second semiconductor thin films. Also described is the device wherein the first thin film is p-type cadmium telluride.

  4. Tungsten polyoxometalate molecules as active nodes for dynamic carrier exchange in hybrid molecular/semiconductor capacitors

    SciTech Connect (OSTI)

    Balliou, A., E-mail: aballiou@imel.demokritos.gr [Institute of Nanoscience and Nanotechnology, NCSR Demokritos, Aghia Paraskevi, Athens 15310 (Greece); Department of Chemical Engineering, NTUA, Zographou Campus, Athens 15773 (Greece); Douvas, A. M.; Normand, P.; Argitis, P.; Glezos, N. [Institute of Nanoscience and Nanotechnology, NCSR Demokritos, Aghia Paraskevi, Athens 15310 (Greece); Tsikritzis, D.; Kennou, S. [Department of Chemical Engineering, University of Patras, University Campus, Patras 26504 (Greece)

    2014-10-14T23:59:59.000Z

    In this work we study the utilization of molecular transition metal oxides known as polyoxometalates (POMs), in particular the Keggin structure anions of the formula PW{sub 12}O{sub 40}{sup 3?}, as active nodes for potential switching and/or fast writing memory applications. The active molecules are being integrated in hybrid Metal-Insulator/POM molecules-Semiconductor capacitors, which serve as prototypes allowing investigation of critical performance characteristics towards the design of more sophisticated devices. The charging ability as well as the electronic structure of the molecular layer is probed by means of electrical characterization, namely, capacitance-voltage and current-voltage measurements, as well as transient capacitance measurements, C (t), under step voltage polarization. It is argued that the transient current peaks observed are manifestations of dynamic carrier exchange between the gate electrode and specific molecular levels, while the transient C (t) curves under conditions of molecular charging can supply information for the rate of change of the charge that is being trapped and de-trapped within the molecular layer. Structural characterization via surface and cross sectional scanning electron microscopy as well as atomic force microscopy, spectroscopic ellipsometry, UV and Fourier-transform IR spectroscopies, UPS, and XPS contribute to the extraction of accurate electronic structure characteristics and open the path for the design of new devices with on-demand tuning of their interfacial properties via the controlled preparation of the POM layer.

  5. Mesoporous Silica-Supported Metal Oxide-Promoted Rh Nanocatalyst for Selective Production of Ethanol from Syngas

    SciTech Connect (OSTI)

    George Kraus

    2010-09-30T23:59:59.000Z

    The objective is to develop a process that will convert synthesis gas from coal into ethanol and then transform the ethanol into hydrogen. Principal investigators from Iowa State University include Dr. George Kraus, Dr. Victor Lin, Marek Pruski, and Dr. Robert Brown. Task 1 involves catalyst development and catalyst scale up. Mesoporous manganese silicate mixed oxide materials will be synthesized, characterized and evaluated. The first-and secondgeneration catalysts have been prepared and scaled up for use in Task 2. The construction of a high-pressure reactor system for producing synthetic liquid fuel from simulated synthesis gas stream has been completed as the first step in Task 2. Using the first- and second generation catalysts, the reactor has demonstrated the production of synthetic liquid fuel from a simulated synthesis gas stream.

  6. Enhanced stability against bias-stress of metal-oxide thin film transistors deposited at elevated temperatures

    SciTech Connect (OSTI)

    Fakhri, M.; Goerrn, P.; Riedl, T. [Institute of Electronic Devices, University of Wuppertal, Rainer-Gruenter-St. 21, 42119 Wuppertal (Germany); Weimann, T.; Hinze, P. [Physikalisch-Technische Bundesanstalt Braunschweig, Bundesallee 100, 38116 Braunschweig (Germany)

    2011-09-19T23:59:59.000Z

    Transparent zinc-tin-oxide (ZTO) thin film transistors (TFTs) have been prepared by DC magnetron sputtering. Compared to reference devices with a channel deposited at room temperature and subsequently annealing at 400 deg. C, a substantially enhanced stability against bias stress is evidenced for devices with in-situ substrate heating during deposition (400 deg. C). A reduced density of sub-gap defect states in TFT channels prepared with in-situ substrate heating is found. Concomitantly, a reduced sensitivity to the adsorption of ambient gases is evidenced for the in-situ heated devices. This finding is of particular importance for an application as driver electronics for organic light emitting diode displays.

  7. Semiconductor radiation detector

    DOE Patents [OSTI]

    Bell, Zane W. (Oak Ridge, TN); Burger, Arnold (Knoxville, TN)

    2010-03-30T23:59:59.000Z

    A semiconductor detector for ionizing electromagnetic radiation, neutrons, and energetic charged particles. The detecting element is comprised of a compound having the composition I-III-VI.sub.2 or II-IV-V.sub.2 where the "I" component is from column 1A or 1B of the periodic table, the "II" component is from column 2B, the "III" component is from column 3A, the "IV" component is from column 4A, the "V" component is from column 5A, and the "VI" component is from column 6A. The detecting element detects ionizing radiation by generating a signal proportional to the energy deposited in the element, and detects neutrons by virtue of the ionizing radiation emitted by one or more of the constituent materials subsequent to capture. The detector may contain more than one neutron-sensitive component.

  8. Semiconductor Bridge Cable Test

    SciTech Connect (OSTI)

    KING, TONY L.

    2002-01-01T23:59:59.000Z

    The semiconductor bridge (SCB) is an electroexplosive device used to initiate detonators. A C cable is commonly used to connect the SCB to a firing set. A series of tests were performed to identify smaller, lighter cables for firing single and multiple SCBs. This report provides a description of these tests and their results. It was demonstrated that lower threshold voltages and faster firing times can be achieved by increasing the wire size, which reduces ohmic losses. The RF 100 appears to be a reasonable substitute for C cable when firing single SCBs. This would reduce the cable volume by 68% and the weight by 67% while increasing the threshold voltage by only 22%. In general, RG 58 outperforms twisted pair when firing multiple SCBs in parallel. The RG 58's superior performance is attributed to its larger conductor size.

  9. Semiconductor device PN junction fabrication using optical processing of amorphous semiconductor material

    DOE Patents [OSTI]

    Sopori, Bhushan; Rangappan, Anikara

    2014-11-25T23:59:59.000Z

    Systems and methods for semiconductor device PN junction fabrication are provided. In one embodiment, a method for fabricating an electrical device having a P-N junction comprises: depositing a layer of amorphous semiconductor material onto a crystalline semiconductor base, wherein the crystalline semiconductor base comprises a crystalline phase of a same semiconductor as the amorphous layer; and growing the layer of amorphous semiconductor material into a layer of crystalline semiconductor material that is epitaxially matched to the lattice structure of the crystalline semiconductor base by applying an optical energy that penetrates at least the amorphous semiconductor material.

  10. Metallization and insulization during impact

    SciTech Connect (OSTI)

    Gilman, J.J.

    1992-10-01T23:59:59.000Z

    It is pointed out that the large strains produced by hypervelocity impacts can be expected to produce dramatic changes in the chemical bonding (electronic structures) of materials. This will change the mechanical behavior towards increased ductility when a semiconductor is compressed until it becomes metallic; and towards increased brittleness when a transition metal is expanded so as to localize its d-band electrons. Both isotropic compression (expansion) and shear strains can cause these transformations. Critical deformation criteria are given based on the observed cubic to tetragonal transformations in compressed semiconductors.

  11. Semiconductor structures having electrically insulating and conducting portions formed from an AlSb-alloy layer

    DOE Patents [OSTI]

    Spahn, Olga B. (Albuquerque, NM); Lear, Kevin L. (Albuquerque, NM)

    1998-01-01T23:59:59.000Z

    A semiconductor structure. The semiconductor structure comprises a plurality of semiconductor layers formed on a substrate including at least one layer of a III-V compound semiconductor alloy comprising aluminum (Al) and antimony (Sb), with at least a part of the AlSb-alloy layer being chemically converted by an oxidation process to form superposed electrically insulating and electrically conducting portions. The electrically insulating portion formed from the AlSb-alloy layer comprises an oxide of aluminum (e.g. Al.sub.2 O.sub.3), while the electrically conducting portion comprises Sb. A lateral oxidation process allows formation of the superposed insulating and conducting portions below monocrystalline semiconductor layers for forming many different types of semiconductor structures having particular utility for optoelectronic devices such as light-emitting diodes, edge-emitting lasers, vertical-cavity surface-emitting lasers, photodetectors and optical modulators (waveguide and surface normal), and for electronic devices such as heterojunction bipolar transistors, field-effect transistors and quantum-effect devices. The invention is expected to be particularly useful for forming light-emitting devices for use in the 1.3-1.6 .mu.m wavelength range, with the AlSb-alloy layer acting to define an active region of the device and to effectively channel an electrical current therein for efficient light generation.

  12. Combined Charge Carrier Transport and Photoelectrochemical Characterization of BiVO4 Single Crystals: Intrinsic Behavior of a Complex Metal Oxide

    SciTech Connect (OSTI)

    Rettie, Alexander J.; Lee, Heung Chan; Marshall, Luke G.; Lin, Jung-Fu; Capen, Cigdem; Lindemuth, Jeffrey; McCloy, John S.; Zhou, Jianshi; Bard, Allen J.; Mullins, C. Buddie

    2013-07-08T23:59:59.000Z

    ABSTRACT: Bismuth vanadate (BiVO4) is a promising photoelectrode material for the oxidation of water, but fundamental studies of this material are lacking. To address this, we report electrical and photoelectrochemical (PEC) properties of BiVO4 single crystals (undoped, 0.6% Mo and 0.3% W:BiVO4) grown using the floating zone technique. We demonstrate that a small polaron hopping conduction mechanism dominates from 250-400 K, transitioning to a variable range hopping mechanism at lower temperatures. An anisotropy ratio of ~3 was observed along the c-axis, attributed to the layered structure of BiVO4. Measurements of the AC field Hall effect yielded an electron mobility of ~0.2 cm2 V-1 s-1 for Mo and W:BiVO4 at 300 K. By application of the Gärtner model, a hole diffusion length of ~140 nm was estimated. As a result of low carrier mobility, attempts to measure the DC Hall effect were unsuccessful. Analyses of the Raman spectra showed that Mo and W substituted for V and acted as donor impurities. Mott-Schottky analysis of electrodes with the (001) face exposed yielded a flat band potential of 0.03-0.08 V vs. RHE, while incident photon conversion efficiency tests showed that the dark coloration of the doped single crystals did not result in additional photocurrent. Comparison of these intrinsic properties to other metal oxides for PEC applications gives valuable insight into this material as a photoanode.

  13. Method of forming supported doped palladium containing oxidation catalysts

    DOE Patents [OSTI]

    Mohajeri, Nahid

    2014-04-22T23:59:59.000Z

    A method of forming a supported oxidation catalyst includes providing a support comprising a metal oxide or a metal salt, and depositing first palladium compound particles and second precious metal group (PMG) metal particles on the support while in a liquid phase including at least one solvent to form mixed metal comprising particles on the support. The PMG metal is not palladium. The mixed metal particles on the support are separated from the liquid phase to provide the supported oxidation catalyst.

  14. Correlation of Chemisorption and Electronic Effects for Metal Oxide Interfaces: Transducing Principles for Temperature Programmed Gas Microsensors (Final Report)

    SciTech Connect (OSTI)

    S. Semancik; R. E. Cavicchi; D. L. DeVoe; T. J. McAvoy [National Institute of Standards and Technology (US)]|[University of Maryland (US)

    2001-12-21T23:59:59.000Z

    This Final Report describes efforts and results for a 3-year DoE/OST-EMSP project centered at NIST. The multidisciplinary project investigated scientific and technical concepts critical for developing tunable, MEMS-based, gas and vapor microsensors that could be applied for monitoring the types of multiple analytes (and differing backgrounds) encountered at DoE waste sites. Micromachined ''microhotplate'' arrays were used as platforms for fabricating conductometric sensor prototypes, and as microscale research tools. Efficient microarray techniques were developed for locally depositing and then performance evaluating thin oxide films, in order to correlate gas sensing characteristics with properties including composition, microstructure, thickness and surface modification. This approach produced temperature-dependent databases on the sensitivities of sensing materials to varied analytes (in air) which enable application-specific tuning of microsensor arrays. Mechanistic studies on adsorb ate transient phenomena were conducted to better understand the ways in which rapid temperature programming schedules can be used to produce unique response signatures and increase information density in microsensor signals. Chemometric and neural network analyses were also employed in our studies for recognition and quantification of target analytes.

  15. Compatibility of refractory metal boride/oxide composites at ultra-high temperatures. Final report, Sep 87-Mar 90

    SciTech Connect (OSTI)

    Bronson, A.; Ma, Y.T.; Mutso, R.R.

    1990-12-01T23:59:59.000Z

    The compatibility of the HfO2/HfSi2/HfB2 phases has been investigated in an argon atmosphere at 1800 deg, 1700 deg and 1600 deg C. At the three temperatures investigated, HfB 2 was determined to be relatively inert to either the oxide or silicide phases when examined with the scanning electron microscope and optical microscope. At 1800 deg C, a reactive product was found between the hafnia and hafnium dislicide phases with a wavy interface moving, parabolically with respect to time. The microstructural analysis of the interface suggests that liquid contributes to the interfacial reactions. In addition, two-solid phases (Hf 2 Si and HfSi) were formed at temperature along with silicide and silicate liquids located between HfSi2 and HfO2. At 1600 deg C for annealing times from 4 to 50 hours, the HfSi 2 /HfO 2 interface does not react as inferred from the acquired constant thickness of the silicide layer.

  16. Enhancement of Bacterial Transport in Aerobic and Anaerobic Environments: Assessing the Effect of Metal Oxide Chemical Heterogeneities

    SciTech Connect (OSTI)

    T.C. Onstott

    2005-09-30T23:59:59.000Z

    The goal of our research was to understand the fundamental processes that control microbial transport in physically and chemically heterogeneous aquifers and from this enhanced understanding determine the requirements for successful, field-scale delivery of microorganisms to metal contaminated subsurface sites. Our specific research goals were to determine; (1) the circumstances under which the preferential adsorption of bacteria to Fe, Mn, and Al oxyhydroxides influences field-scale bacterial transport, (2) the extent to which the adhesion properties of bacterial cells affect field-scale bacterial transport, (3) whether microbial Fe(III) reduction can enhance field-scale transport of Fe reducing bacteria (IRB) and other microorganisms and (4) the effect of field-scale physical and chemical heterogeneity on all three processes. Some of the spin-offs from this basic research that can improve biostimulation and bioaugmentation remediation efforts at contaminated DOE sites have included; (1) new bacterial tracking tools for viable bacteria; (2) an integrated protocol which combines subsurface characterization, laboratory-scale experimentation, and scale-up techniques to accurately predict field-scale bacterial transport; and (3) innovative and inexpensive field equipment and methods that can be employed to enhance Fe(III) reduction and microbial transport and to target microbial deposition under both aerobic and anaerobic conditions.

  17. Mathematical Modeling of Semiconductor Devices

    E-Print Network [OSTI]

    Jüngel, Ansgar

    fibers. · Optoelectronic emitters convert an electronic signal into light. Examples are light-emitting diodes (LED) used in displays and indication lambs and semiconductor lasers used in compact disk systems

  18. Seebeck coefficient in organic semiconductors

    E-Print Network [OSTI]

    Venkateshvaran, Deepak

    2014-07-01T23:59:59.000Z

    Seebeck coefficient in organic semiconductors A dissertation submitted for the degree of Doctor of Philosophy Deepak Venkateshvaran Fitzwilliam College & Optoelectronics Group, Cavendish Laboratory University of Cambridge February 2014 “The end...

  19. Modeling the semiconductor industry dynamics

    E-Print Network [OSTI]

    Wu, Kailiang

    2008-01-01T23:59:59.000Z

    The semiconductor industry is an exciting and challenging industry. Strong demand at the application end, plus the high capital intensity and rapid technological innovation in manufacturing, makes it difficult to manage ...

  20. Comparative study of the reactions of metal oxides with H{sub 2}S and SO{sub 2}. Technical progress report, July--September 1991

    SciTech Connect (OSTI)

    Sotirchos, S.V.

    1991-10-01T23:59:59.000Z

    The primary objective of this project is the investigation of the effects of pore structure on the capacity of porous metal oxides for removal of gaseous pollutants from flue gases of power plants (SO{sub 2}) and hot coal gas (primarily H{sub 2}S). Specifically, we intend to appropriately exploit the differences of the sulfidation and sulfation reactions (for instance, different molar volumes of solid products) to elucidate the dependence of the sorptive capacity of a porous sorbent on its physical microstructure. The following tasks have been identified in the proposed project: (1) Literature survey and identification of solids to be used in experimental studies. (2) Experimental study of the reaction of the chosen solids with SO{sub 2} and/or H{sub 2}S. (3) Experimental study of the evolution of the structure of the solids during reaction with SO{sub 2} and/or H{sub 2}S using pore structure analysis and effective diffusivity measurements. (4) Model testing and validation using the obtained experimental data.

  1. Influence of growth temperature on electrical, optical, and plasmonic properties of aluminum:zinc oxide films grown by radio frequency magnetron sputtering

    SciTech Connect (OSTI)

    Dondapati, Hareesh; Santiago, Kevin; Pradhan, A. K. [Center for Materials Research, Norfolk State University, 700 Park Avenue, Norfolk, Virginia 23504 (United States)] [Center for Materials Research, Norfolk State University, 700 Park Avenue, Norfolk, Virginia 23504 (United States)

    2013-10-14T23:59:59.000Z

    We have investigated the responsible mechanism for the observation of metallic conductivity at room temperature and metal-semiconductor transition (MST) at lower temperatures for aluminum-doped zinc oxide (AZO) films. AZO films were grown on glass substrates by radio-frequency magnetron sputtering with varying substrate temperatures (T{sub s}). The films were found to be crystalline with the electrical resistivity close to 1.1 × 10{sup ?3} ? cm and transmittance more than 85% in the visible region. The saturated optical band gap of 3.76 eV was observed for the sample grown at T{sub s} of 400 °C, however, a slight decrease in the bandgap was noticed above 400 °C, which can be explained by Burstein–Moss effect. Temperature dependent resistivity measurements of these highly conducting and transparent films showed a MST at ?110 K. The observed metal-like and metal-semiconductor transitions are explained by taking into account the Mott phase transition and localization effects due to defects. All AZO films demonstrate crossover in permittivity from positive to negative and low loss in the near-infrared region, illustrating its applications for plasmonic metamaterials, including waveguides for near infrared telecommunication region. Based on the results presented in this study, the low electrical resistivity and high optical transmittance of AZO films suggested a possibility for the application in the flexible electronic devices, such as transparent conducting oxide film on LEDs, solar cells, and touch panels.

  2. A new family of metal chalogenide thin film electrodes for photoelectrochemical applications

    SciTech Connect (OSTI)

    Rajeshwar, K.; Tacconi, N.R. de [Univ. of Texas, Arlington, TX (United States)

    1996-10-01T23:59:59.000Z

    A new family of metal/semiconductor electrocomposite photoelectrodes is described for photoelectrochemical (PEC) applications. These electrocomposites are prepared from an aqueous dispersion containing the targeted metal (in ionic form) and the semiconductor particles. Electrodeposition of the metal affords a matrix in which the semiconductor particles are occluded. This approach is illustrated for nickel/TiO{sub 2} and nickel/CdS model candidates. The influence of preparation variables (deposition potential, temperature, pH, semiconductor content) on the PEC behavior is described.

  3. Wide-Bandgap Semiconductors

    SciTech Connect (OSTI)

    Chinthavali, M.S.

    2005-11-22T23:59:59.000Z

    With the increase in demand for more efficient, higher-power, and higher-temperature operation of power converters, design engineers face the challenge of increasing the efficiency and power density of converters [1, 2]. Development in power semiconductors is vital for achieving the design goals set by the industry. Silicon (Si) power devices have reached their theoretical limits in terms of higher-temperature and higher-power operation by virtue of the physical properties of the material. To overcome these limitations, research has focused on wide-bandgap materials such as silicon carbide (SiC), gallium nitride (GaN), and diamond because of their superior material advantages such as large bandgap, high thermal conductivity, and high critical breakdown field strength. Diamond is the ultimate material for power devices because of its greater than tenfold improvement in electrical properties compared with silicon; however, it is more suited for higher-voltage (grid level) higher-power applications based on the intrinsic properties of the material [3]. GaN and SiC power devices have similar performance improvements over Si power devices. GaN performs only slightly better than SiC. Both SiC and GaN have processing issues that need to be resolved before they can seriously challenge Si power devices; however, SiC is at a more technically advanced stage than GaN. SiC is considered to be the best transition material for future power devices before high-power diamond device technology matures. Since SiC power devices have lower losses than Si devices, SiC-based power converters are more efficient. With the high-temperature operation capability of SiC, thermal management requirements are reduced; therefore, a smaller heat sink would be sufficient. In addition, since SiC power devices can be switched at higher frequencies, smaller passive components are required in power converters. Smaller heat sinks and passive components result in higher-power-density power converters. With the advent of the use of SiC devices it is imperative that models of these be made available in commercial simulators. This enables power electronic designers to simulate their designs for various test conditions prior to fabrication. To build an accurate transistor-level model of a power electronic system such as an inverter, the first step is to characterize the semiconductor devices that are present in the system. Suitable test beds need to be built for each device to precisely test the devices and obtain relevant data that can be used for modeling. This includes careful characterization of the parasitic elements so as to emulate the test setup as closely as possible in simulations. This report is arranged as follows: Chapter 2--The testing and characterization of several diodes and power switches is presented. Chapter 3--A 55-kW hybrid inverter (Si insulated gate bipolar transistor--SiC Schottky diodes) device models and test results are presented. A detailed description of the various test setups followed by the parameter extraction, modeling, and simulation study of the inverter performance is presented. Chapter 4--A 7.5-kW all-SiC inverter (SiC junction field effect transistors (JFET)--SiC Schottky diodes) was built and tested. The models built in Saber were validated using the test data and the models were used in system applications in the Saber simulator. The simulation results and a comparison of the data from the prototype tests are discussed in this chapter. Chapter 5--The duration test results of devices utilized in buck converters undergoing reliability testing are presented.

  4. 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.

  5. Friction stir welding and processing of oxide dispersion strengthened (ODS) alloys

    DOE Patents [OSTI]

    Ren, Weiju

    2014-11-11T23:59:59.000Z

    A method of welding including forming a filler material of a first oxide dispersoid metal, the first oxide dispersoid material having first strengthening particles that compensate for decreases in weld strength of friction stir welded oxide dispersoid metals; positioning the filler material between a first metal structure and a second metal structure each being comprised of at least a second oxide dispersoid metal; and friction welding the filler material, the first metal structure and the second metal structure to provide a weld.

  6. A model for predicting the damage and oxidation dependent life of SCS-6/Ti-B21S [0]4 metal matrix composite

    E-Print Network [OSTI]

    Foulk, James Wesley

    1997-01-01T23:59:59.000Z

    A method for predicting the life of an embrittled metal matrix composite using the finite element method coupled with models for material inelasticity, surface embrittlement, and crack propagation was developed herein. The titanium metal matrix...

  7. Electromagnetic compatibility in semiconductor manufacturing

    SciTech Connect (OSTI)

    Montoya, J.A. [Intel Corp., Hillsboro, OR (United States)

    1995-12-31T23:59:59.000Z

    Electromagnetic Interference (EMI) causes problems in semiconductor manufacturing facilities that range from nuisances to major disruptions of production. In many instances, these issues are addressed in a reactionary rather than proactive manner by individuals who do not have the experience or the equipment necessary to combat EMI problems in a timely, cost effective manner. This approach leads to expensive retrofits, reduced equipment availability, long recovery times, and in some cases, line yield impacts. The goal of electromagnetic compatibility (EMC) in semiconductor manufacturing is to ensure that semiconductor process, metrology, and support equipment operate as intended without being affected by electromagnetic disturbances either transmitted through air (radiated interference), or transferred into the equipment via a conductive media (conducted interference). Rather than being neglected until serious issues arise, EMC should be considered in the early stages of facility design, in order to gain the most benefit at the lowest cost.

  8. Optical Properties and Potential Applications of Doped Semiconductor...

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

    Optical Properties and Potential Applications of Doped Semiconductor Nanoparticles. Optical Properties and Potential Applications of Doped Semiconductor Nanoparticles. Abstract:...

  9. Origin of deep subgap states in amorphous indium gallium zinc oxide: Chemically disordered coordination of oxygen

    SciTech Connect (OSTI)

    Sallis, S.; Williams, D. S. [Materials Science and Engineering, Binghamton University, Binghamton, New York 13902 (United States); Butler, K. T.; Walsh, A. [Center for Sustainable Technologies and Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Quackenbush, N. F. [Department of Physics, Applied Physics, and Astronomy, Binghamton University, Binghamton, New York 13902 (United States); Junda, M.; Podraza, N. J. [Department of Physics and Astronomy, University of Toledo, Toledo, Ohio 43606 (United States); Fischer, D. A.; Woicik, J. C. [Materials Science and Engineering Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); White, B. E.; Piper, L. F. J., E-mail: lpiper@binghamton.edu [Department of Physics, Applied Physics, and Astronomy, Binghamton University, Binghamton, New York 13902 (United States); Materials Science and Engineering, Binghamton University, Binghamton, New York 13902 (United States)

    2014-06-09T23:59:59.000Z

    The origin of the deep subgap states in amorphous indium gallium zinc oxide (a-IGZO), whether intrinsic to the amorphous structure or not, has serious implications for the development of p-type transparent amorphous oxide semiconductors. We report that the deep subgap feature in a-IGZO originates from local variations in the oxygen coordination and not from oxygen vacancies. This is shown by the positive correlation between oxygen composition and subgap intensity as observed with X-ray photoelectron spectroscopy. We also demonstrate that the subgap feature is not intrinsic to the amorphous phase because the deep subgap feature can be removed by low-temperature annealing in a reducing environment. Atomistic calculations of a-IGZO reveal that the subgap state originates from certain oxygen environments associated with the disorder. Specifically, the subgap states originate from oxygen environments with a lower coordination number and/or a larger metal-oxygen separation.

  10. Semiconductor structures having electrically insulating and conducting portions formed from an AlSb-alloy layer

    DOE Patents [OSTI]

    Spahn, O.B.; Lear, K.L.

    1998-03-10T23:59:59.000Z

    The semiconductor structure comprises a plurality of semiconductor layers formed on a substrate including at least one layer of a III-V compound semiconductor alloy comprising aluminum (Al) and antimony (Sb), with at least a part of the AlSb-alloy layer being chemically converted by an oxidation process to form superposed electrically insulating and electrically conducting portions. The electrically insulating portion formed from the AlSb-alloy layer comprises an oxide of aluminum (e.g., Al{sub 2}O{sub 3}), while the electrically conducting portion comprises Sb. A lateral oxidation process allows formation of the superposed insulating and conducting portions below monocrystalline semiconductor layers for forming many different types of semiconductor structures having particular utility for optoelectronic devices such as light-emitting diodes, edge-emitting lasers, vertical-cavity surface-emitting lasers, photodetectors and optical modulators (waveguide and surface normal), and for electronic devices such as heterojunction bipolar transistors, field-effect transistors and quantum-effect devices. The invention is expected to be particularly useful for forming light-emitting devices for use in the 1.3--1.6 {mu}m wavelength range, with the AlSb-alloy layer acting to define an active region of the device and to effectively channel an electrical current therein for efficient light generation. 10 figs.

  11. Correlated exciton dynamics in semiconductor nanostructures

    E-Print Network [OSTI]

    Wen, Patrick, Ph. D. Massachusetts Institute of Technology

    2013-01-01T23:59:59.000Z

    The absorption and dissipation of energy in semiconductor nanostructures are often determined by excited electron dynamics. In semiconductors, one fundamentally important electronic state is an exciton, an excited electron ...

  12. Method of preparing nitrogen containing semiconductor material

    DOE Patents [OSTI]

    Barber, Greg D.; Kurtz, Sarah R.

    2004-09-07T23:59:59.000Z

    A method of combining group III elements with group V elements that incorporates at least nitrogen from a nitrogen halide for use in semiconductors and in particular semiconductors in photovoltaic cells.

  13. Thin-film solar cell fabricated on a flexible metallic substrate

    DOE Patents [OSTI]

    Tuttle, John R.; Noufi, Rommel; Hasoon, Falah S.

    2006-05-30T23:59:59.000Z

    A thin-film solar cell (10) is provided. The thin-film solar cell (10) comprises a flexible metallic substrate (12) having a first surface and a second surface. A back metal contact layer (16) is deposited on the first surface of the flexible metallic substrate (12). A semiconductor absorber layer (14) is deposited on the back metal contact. A photoactive film deposited on the semiconductor absorber layer (14) forms a heterojunction structure and a grid contact (24) deposited on the heterjunction structure. The flexible metal substrate (12) can be constructed of either aluminium or stainless steel. Furthermore, a method of constructing a solar cell is provided. The method comprises providing an aluminum substrate (12), depositing a semiconductor absorber layer (14) on the aluminum substrate (12), and insulating the aluminum substrate (12) from the semiconductor absorber layer (14) to inhibit reaction between the aluminum substrate (12) and the semiconductor absorber layer (14).

  14. Thin-Film Solar Cell Fabricated on a Flexible Metallic Substrate

    DOE Patents [OSTI]

    Tuttle, J. R.; Noufi, R.; Hasoon, F. S.

    2006-05-30T23:59:59.000Z

    A thin-film solar cell (10) is provided. The thin-film solar cell (10) comprises a flexible metallic substrate (12) having a first surface and a second surface. A back metal contact layer (16) is deposited on the first surface of the flexible metallic substrate (12). A semiconductor absorber layer (14) is deposited on the back metal contact. A photoactive film deposited on the semiconductor absorber layer (14) forms a heterojunction structure and a grid contact (24) deposited on the heterjunction structure. The flexible metal substrate (12) can be constructed of either aluminium or stainless steel. Furthermore, a method of constructing a solar cell is provided. The method comprises providing an aluminum substrate (12), depositing a semiconductor absorber layer (14) on the aluminum substrate (12), and insulating the aluminum substrate (12) from the semiconductor absorber layer (14) to inhibit reaction between the aluminum substrate (12) and the semiconductor absorber layer (14).

  15. Sandia National Laboratories: Semiconductor Revolution

    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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -theErikGroundbreaking Work onClimateSemiconductor Revolution Semiconductor

  16. Semiconductor electrode with improved photostability characteristics

    DOE Patents [OSTI]

    Frank, A.J.

    1985-02-19T23:59:59.000Z

    An electrode is described for use in photoelectrochemical cells having an electrolyte which includes an aqueous constituent. The electrode consists of a semiconductor and a hydrophobic film disposed between the semiconductor and the aqueous constituent. The hydrophobic film is adapted to permit charges to pass therethrough while substantially decreasing the activity of the aqueous constituent at the semiconductor surface thereby decreasing the photodegradation of the semiconductor electrode.

  17. Semiconductor nanocrystal-based phagokinetic tracking

    DOE Patents [OSTI]

    Alivisatos, A Paul; Larabell, Carolyn A; Parak, Wolfgang J; Le Gros, Mark; Boudreau, Rosanne

    2014-11-18T23:59:59.000Z

    Methods for determining metabolic properties of living cells through the uptake of semiconductor nanocrystals by cells. Generally the methods require a layer of neutral or hydrophilic semiconductor nanocrystals and a layer of cells seeded onto a culture surface and changes in the layer of semiconductor nanocrystals are detected. The observed changes made to the layer of semiconductor nanocrystals can be correlated to such metabolic properties as metastatic potential, cell motility or migration.

  18. 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 ...

  19. First-principles study of thin magnetic transition-metal silicide films on Si(001) Hua Wu, Peter Kratzer, and Matthias Scheffler

    E-Print Network [OSTI]

    First-principles study of thin magnetic transition-metal silicide films on Si(001) Hua Wu, Peter of ferromag- netic FM materials have been suggested for the fabrication of metal/semiconductor heterojunctions s : 75.70. i, 73.20.At, 68.35.Md I. INTRODUCTION Metal-semiconductor heterojunctions have received much

  20. Neutron detection using boron gallium nitride semiconductor material

    SciTech Connect (OSTI)

    Atsumi, Katsuhiro [Department of Electrical and Electronic Engineering, Graduate School of Engineering, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8561 (Japan); Inoue, Yoku; Nakano, Takayuki, E-mail: ttnakan@ipc.shizuoka.ac.jp [Department of Electrical and Materials Science, Graduate School of Engineering, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8561 (Japan); Mimura, Hidenori; Aoki, Toru [Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8011 (Japan)

    2014-03-01T23:59:59.000Z

    In this study, we developed a new neutron-detection device using a boron gallium nitride (BGaN) semiconductor in which the B atom acts as a neutron converter. BGaN and gallium nitride (GaN) samples were grown by metal organic vapor phase epitaxy, and their radiation detection properties were evaluated. GaN exhibited good sensitivity to ?-rays but poor sensitivity to ?-rays. Moreover, we confirmed that electrons were generated in the depletion layer under neutron irradiation. This resulted in a neutron-detection signal after ?-rays were generated by the capture of neutrons by the B atoms. These results prove that BGaN is useful as a neutron-detecting semiconductor material.