National Library of Energy BETA

Sample records for ni za tion

  1. CUSSSFIC4TION CMUXLLq

    Office of Legacy Management (LM)

    CUSSSFIC4TION CMUXLLq RITE AUG 1 7 1962 Fcx the Atomic. Energy Commisaion~ Chief. Declaseifle@tlon Brar\qh F-mm A. B. Grsaingsr (Other ends tifmtioel) The die wae foutq3 to workvery satiafactorilywiti thlanew Qpeof incert, andncm,of tbepmvLouedsfeotaofeoo+tH&' iOitYwaslmd. D&e& ._: . . ..YG ~Kl.3. i>ro;rid3 -&I:: clcsuro on bct.k.mds of the .plece m & Die #l, is also to be tried outoo 4zgust22. Barr~l~or~~~Die~~hadalaobeenawlLfiedta' plwidesd~do~-

  2. CLASSIFICdTION CAWXL~ DAm

    Office of Legacy Management (LM)

    CLASSIFICdTION CAWXL~ DAm NAR 6 1969 For the Atomic EhergY hDh=+= ,' ROBERT L JACKSON /(\' t' for the Chief, Declassification B~Jx~

  3. Ni Ni: University of California - Los Angeles

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

    Ni Ni: University of California - Los Angeles Alumni Link: Opportunities, News and Resources for Former Employees Latest Issue:September 2015 all issues All Issues » submit Ni Ni: University of California - Los Angeles Condensed matter January 1, 2015 Ni Ni Ni Ni Contact Linda Anderman Email Ni Ni Ni Ni now at the University of California-Los Angeles After finishing her work at Princeton, Ni Ni began at the Lab as a postdoc in 2012 with the Condensed Matter and Magnetic Science Group. Ni was

  4. The SpallaTion

    Office of Environmental Management (EM)

    The Science Behind Cheaper Biofuels The Science Behind Cheaper Biofuels August 15, 2011 - 11:50am Addthis Brookhaven National Laboratory is modeling the metabolic processes in rapeseed plants to optimize production of plant oils for biofuels. Shown above are developing embryos extracted from a growing rapeseed plant. The embryos accumulate seed oils which represent the most energy-dense form of biologically stored sunlight, and have great potential as renewable resources for fuel and industrial

  5. Airtricity Developments NI Ltd | Open Energy Information

    Open Energy Info (EERE)

    Airtricity Developments NI Ltd Jump to: navigation, search Name: Airtricity Developments NI Ltd Place: Belfast, Northern Ireland, United Kingdom Zip: BT2 7AF Sector: Wind energy...

  6. SF 6432-NI (04-95)

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

    Retrieve latest version electronically. SF 6432-NI (061411) SECTION II STANDARD TERMS ... Control : SF 6432-NI Title: Standard Terms & Conditions for Fixed Price Contracts With ...

  7. Significant Reduction in NiO Band Gap Upon Formation of LixNi1...

    Office of Scientific and Technical Information (OSTI)

    Significant Reduction in NiO Band Gap Upon Formation of LixNi1-xO alloys: Applications To Solar Energy Conversion Citation Details In-Document Search Title: Significant Reduction ...

  8. SF 6432-NI (02-22-10)

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

    be controlling. All deliverables under this Contract shall use andor be in the English language. NI14 - PAYMENT Contractor agrees to provide invoices within 60 days of...

  9. SF 6432-NI (04-95)

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

    be controlling. All deliverables under this Contract shall use andor be in the English language. NI15 - PAYMENT Contractor agrees to provide invoices within 60 days of...

  10. SF 6432-NI (04-95)

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

    be controlling. All deliverables under this Contract shall use andor be in the English language. NI14 - PAYMENT Contractor agrees to provide invoices within 60 days of...

  11. SF 6432-NI (04-95)

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

    descending order of precedence: (1) Section I; (2) SF 6432-NI, Section II. The English language version of this Contract shall be controlling. All deliverables under this...

  12. Ni Clusterbank Replacement Project | Argonne Leadership Computing...

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

    Ni Clusterbank Replacement Project Event Sponsor: Argonne Leadership Computing Facility Seminar Start Date: Oct 20 2015 - 12:00pm BuildingRoom: Building 241Room D173...

  13. UTICA 4, NEW YORK COFIPOR~TION

    Office of Legacy Management (LM)

    H. J. Zmjian, GE", of the ncmbers of our orzaniza- has a "Q" cl:arance and our President is rcqueoting an 'L" clearance for some of us. -'n would appreciate it very much if you ...

  14. Vykson Formerly Turbine Developments NI Ltd | Open Energy Information

    Open Energy Info (EERE)

    Vykson Formerly Turbine Developments NI Ltd Jump to: navigation, search Name: Vykson (Formerly Turbine Developments (NI) Ltd) Place: Canterbury, England, United Kingdom Zip: BR6...

  15. Ion irradiation induced defect evolution in Ni and Ni-based FCC equiatomic binary alloys

    SciTech Connect (OSTI)

    Jin, Ke; Zhang, Yanwen; Bei, Hongbin

    2016-01-01

    In order to explore the chemical effects on radiation response of alloys with multi-principal elements, defect evolution under Au ion irradiation was investigated in the elemental Ni, equiatomic NiCo and NiFe alloys. Single crystals were successfully grown in an optical floating zone furnace and their (100) surfaces were irradiated with 3 MeV Au ions at fluences ranging from 1 × 1013 to 5 × 1015 ions cm–2 at room temperature. The irradiation-induced defect evolution was analyzed by using ion channeling technique. Experiment shows that NiFe is more irradiation-resistant than NiCo and pure Ni at low fluences. With continuously increasing the ion fluences, damage level is eventually saturated for all materials but at different dose levels. The saturation level in pure Ni appears at relatively lower irradiation fluence than the alloys, suggesting that damage accumulation slows down in the alloys. Here, under high-fluence irradiations, pure Ni has wider damage ranges than the alloys, indicating that defects in pure Ni have high mobility.

  16. Layering and temperature-dependent magnetization and anisotropy of naturally produced Ni/NiO multilayers

    SciTech Connect (OSTI)

    Pappas, S. D.; Trachylis, D.; Velgakis, M. J.; Kapaklis, V.; Joensson, P. E.; Papaioannou, E. Th.; Delimitis, A.; Poulopoulos, P.; Fumagalli, P.; Politis, C.

    2012-09-01

    Ni/NiO multilayers were grown by magnetron sputtering at room temperature, with the aid of the natural oxidation procedure. That is, at the end of the deposition of each single Ni layer, air is let to flow into the vacuum chamber through a leak valve. Then, a very thin NiO layer ({approx}1.2 nm) is formed. Simulated x-ray reflectivity patterns reveal that layering is excellent for individual Ni-layer thickness larger than 2.5 nm, which is attributed to the intercalation of amorphous NiO between the polycrystalline Ni layers. The magnetization of the films, measured at temperatures 5-300 K, has almost bulk-like value, whereas the films exhibit a trend to perpendicular magnetic anisotropy (PMA) with an unusual significant positive interface anisotropy contribution, which presents a weak temperature dependence. The power-law behavior of the multilayers indicates a non-negligible contribution of higher order anisotropies in the uniaxial anisotropy. Bloch-law fittings for the temperature dependence of the magnetization in the spin-wave regime show that the magnetization in the multilayers decreases faster as a function of temperature than the one of bulk Ni. Finally, when the individual Ni-layer thickness decreases below 2 nm, the multilayer stacking vanishes, resulting in a dramatic decrease of the interface magnetic anisotropy and consequently in a decrease of the perpendicular magnetic anisotropy.

  17. Ion irradiation induced defect evolution in Ni and Ni-based FCC equiatomic binary alloys

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

    Jin, Ke; Zhang, Yanwen; Bei, Hongbin

    2016-01-01

    In order to explore the chemical effects on radiation response of alloys with multi-principal elements, defect evolution under Au ion irradiation was investigated in the elemental Ni, equiatomic NiCo and NiFe alloys. Single crystals were successfully grown in an optical floating zone furnace and their (100) surfaces were irradiated with 3 MeV Au ions at fluences ranging from 1 × 1013 to 5 × 1015 ions cm–2 at room temperature. The irradiation-induced defect evolution was analyzed by using ion channeling technique. Experiment shows that NiFe is more irradiation-resistant than NiCo and pure Ni at low fluences. With continuously increasing themore » ion fluences, damage level is eventually saturated for all materials but at different dose levels. The saturation level in pure Ni appears at relatively lower irradiation fluence than the alloys, suggesting that damage accumulation slows down in the alloys. Here, under high-fluence irradiations, pure Ni has wider damage ranges than the alloys, indicating that defects in pure Ni have high mobility.« less

  18. Microsoft Word - NiR.doc

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

    In bacteria, NO is produced by nitrite reductase (NiR), a copper-containing enzyme, which ... required to define the mode of binding of the ligands to the active site copper. ...

  19. SF 6432-NI (04-95)

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

    6432-NI (11-03-2010) SECTION II STANDARD TERMS AND CONDITIONS FOR FIXED PRICE CONTRACTS WITH THE NEWLY INDEPENDENT STATES OF THE FORMER SOVIET UNION INDEX OF CLAUSES. THE FOLLOWING CLAUSES APPLY TO REQUESTS FOR QUOTATION AND CONTRACTS AS INDICATED UNLESS SPECIFICALLY DELETED, OR EXCEPT TO THE EXTENT THEY ARE SPECIFICALLY SUPPLEMENTED OR AMENDED IN WRITING IN THE SIGNATURE PAGE OR SECTION I. NI01 - ACCEPTANCE OF TERMS AND CONDITIONS Contractor, by signing this Agreement, beginning performance,

  20. Electronic circuits having NiAl and Ni.sub.3 Al substrates

    DOE Patents [OSTI]

    Deevi, Seetharama C.; Sikka, Vinod K.

    1999-01-01

    An electronic circuit component having improved mechanical properties and thermal conductivity comprises NiAl and/or Ni.sub.3 Al, upon which an alumina layer is formed prior to applying the conductive elements. Additional layers of copper-aluminum alloy or copper further improve mechanical strength and thermal conductivity.

  1. Photosensitivity of the Ni-A state of [NiFe] hydrogenase from Desulfovibrio vulgaris Miyazaki F with visible light

    SciTech Connect (OSTI)

    Osuka, Hisao; Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5, Takayama-cho, Ikoma-shi, Nara 630-0192 ; Shomura, Yasuhito; Komori, Hirofumi; Shibata, Naoki; Nagao, Satoshi; Higuchi, Yoshiki; CREST, JST, Gobancho, Chiyoda-ku, Tokyo 102-0076 ; Hirota, Shun; CREST, JST, Gobancho, Chiyoda-ku, Tokyo 102-0076

    2013-01-04

    Highlights: Black-Right-Pointing-Pointer Ni-A state of [NiFe] hydrogenase showed light sensitivity. Black-Right-Pointing-Pointer New FT-IR bands were observed with light irradiation of the Ni-A state. Black-Right-Pointing-Pointer EPR g-values of the Ni-A state shifted upon light irradiation. Black-Right-Pointing-Pointer The light-induced state converted back to the Ni-A state under the dark condition. -- Abstract: [NiFe] hydrogenase catalyzes reversible oxidation of molecular hydrogen. Its active site is constructed of a hetero dinuclear Ni-Fe complex, and the oxidation state of the Ni ion changes according to the redox state of the enzyme. We found that the Ni-A state (an inactive unready, oxidized state) of [NiFe] hydrogenase from Desulfovibrio vulgaris Miyazaki F (DvMF) is light sensitive and forms a new state (Ni-AL) with irradiation of visible light. The Fourier transform infrared (FT-IR) bands at 1956, 2084 and 2094 cm{sup -1} of the Ni-A state shifted to 1971, 2086 and 2098 cm{sup -1} in the Ni-AL state. The g-values of g{sub x} = 2.30, g{sub y} = 2.23 and g{sub z} = 2.01 for the signals in the electron paramagnetic resonance (EPR) spectrum of the Ni-A state at room temperature varied for -0.009, +0.012 and +0.010, respectively, upon light irradiation. The light-induced Ni-AL state converted back immediately to the Ni-A state under dark condition at room temperature. These results show that the coordination structure of the Fe site of the Ni-A state of [NiFe] hydrogenase is perturbed significantly by light irradiation with relatively small coordination change at the Ni site.

  2. Blending Cr2O3 into a NiO-Ni electrocatalyst for sustained water splitting

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

    Gong, Ming; Zhou, Wu; Kenney, Michael James; Kapusta, Rich; Cowley, Sam; Wu, Yingpeng; Lu, Bingan; Lin, Meng -Chang; Wang, Di -Yan; Yang, Jiang; et al

    2015-08-24

    The rising H2 economy demands active and durable electrocatalysts based on low-cost, earth-abundant materials for water electrolysis/photolysis. Here we report nanoscale Ni metal cores over-coated by a Cr2O3-blended NiO layer synthesized on metallic foam substrates. The Ni@NiO/Cr2O3 triphase material exhibits superior activity and stability similar to Pt for the hydrogen-evolution reaction in basic solutions. The chemically stable Cr2O3 is crucial for preventing oxidation of the Ni core, maintaining abundant NiO/Ni interfaces as catalytically active sites in the heterostructure and thus imparting high stability to the hydrogen-evolution catalyst. The highly active and stable electrocatalyst enables an alkaline electrolyzer operating at 20more » mA cm–2 at a voltage lower than 1.5 V, lasting longer than 3 weeks without decay. Thus, the non-precious metal catalysts afford a high efficiency of about 15 % for light-driven water splitting using GaAs solar cells.« less

  3. Influence of Ni on Martensitic Phase Transformations in NiTi Shape Memory Alloys

    SciTech Connect (OSTI)

    Frenzel, J.; George, Easo P; Dlouhy, A.; Somsen, Ch.; Wagner, M. F.-X; Eggeler, G.

    2010-01-01

    High-precision data on phase transformation temperatures in NiTi, including numerical expressions for the effect of Ni on M{sub S}, M{sub F}, A{sub S}, A{sub F} and T{sub 0}, are obtained, and the reasons for the large experimental scatter observed in previous studies are discussed. Clear experimental evidence is provided confirming the predictions of Tang et al. 1999 regarding deviations from a linear relation between the thermodynamic equilibrium temperature and Ni concentration. In addition to affecting the phase transition temperatures, increasing Ni contents are found to decrease the width of thermal hysteresis and the heat of transformation. These findings are rationalized on the basis of the crystallographic data of Prokoshkin et al. 2004 and the theory of Ball and James. The results show that it is important to document carefully the details of the arc-melting procedure used to make shape memory alloys and that, if the effects of processing are properly accounted for, precise values for the Ni concentration of the NiTi matrix can be obtained.

  4. Ab initio molecular dynamics investigations of low-energy recoil events in Ni and NiCo

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

    Liu, Bin; Yuan, Fenglin; Jin, Ke; Zhang, Yanwen; Weber, William J.

    2015-10-06

    Low-energy recoil events in pure Ni and the equiatomic NiCo alloy are studied using ab initio molecular dynamics simulations. We found that the threshold displacement energies are strongly dependent on orientation and weakly dependent on composition. The minimum threshold displacement energies are along the [1 1 0] direction in both pure Ni and the NiCo alloy. Compared to pure Ni, the threshold displacement energies increase slightly in the NiCo alloy due to stronger bonds in the alloy, irrespective of the element type of the PKA. A single Ni interstitial occupying the center of a tetrahedron formed by four Ni atomsmore » and a <1 0 0> split interstitial is produced in pure Ni by the recoils, while only the <1 0 0> split interstitial is formed in the NiCo alloy. Compared to the replacement sequences in pure Ni, anti-site defect sequences are observed in the alloy, which have high efficiency for both producing defects and transporting energy outside of the cascade core. These results provide insights into energy transfer processes occurring in equiatomic alloys under irradiation.« less

  5. Ni{sub 3}Al technology transfer

    SciTech Connect (OSTI)

    Sikka, V.K.; Viswanathan, S.; Santella, M.L.

    1997-04-01

    Ductile Ni{sub 3}Al and Ni{sub 3}Al-based alloys have been identified for a range of applications. These applications require the use of material in a variety of product forms such as sheet, plate, bar, wire, tubing, piping, and castings. Although significant progress has been made in the melting, casting, and near-net-shape forming of nickel aluminides, some issues still remain. These include the need for: (1) high-strength castable composition for many applications that have been identified; (2) castability (mold type, fluidity, hot-shortness, porosity, etc.); (3) weld reparability of castings; and (4) workability of cast or powder metallurgy product to sheet, bar, and wire. The four issues listed above can be {open_quotes}show stoppers{close_quotes} for the commercial application of nickel aluminides. This report describes the work completed to address some of these issues during FY 1996.

  6. SF 6432-NI (02-22-10)

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

    3-08-10) SECTION II STANDARD TERMS AND CONDITIONS FOR FIXED PRICE CONTRACTS WITH THE NEWLY INDEPENDENT STATES OF THE FORMER SOVIET UNION INDEX OF CLAUSES THE FOLLOWING CLAUSES APPLY TO REQUESTS FOR QUOTATION AND CONTRACTS AS INDICATED UNLESS SPECIFICALLY DELETED, OR EXCEPT TO THE EXTENT THEY ARE SPECIFICALLY SUPPLEMENTED OR AMENDED IN WRITING IN SECTION I. NI01 - ACCEPTANCE OF TERMS AND CONDITIONS Contractor, by signing this Agreement, beginning performance, and/or delivering Items or services

  7. SF 6432-NI (04-95)

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

    6-08) SECTION II STANDARD TERMS AND CONDITIONS FOR FIXED PRICE CONTRACTS WITH NEW INDEPENDET STATES OF THE FORMER SOVIET UNION INDEX OF CLAUSES THE FOLLOWING CLAUSES APPLY TO REQUESTS FOR QUOTATION AND CONTRACTS AS INDICATED UNLESS SPECIFICALLY DELETED, OR EXCEPT TO THE EXTENT THEY AERE SPECIFICALLY SUPPLEMENTED OR AMENDED IN WRITING IN THE SIGNATURE PAGE OR SECTION I. NI01 - ACCEPTANCE OF TERMS AND CONDITIONS Contractor, by signing this Agreement, beginning performance, and/or delivering Items

  8. Local structure study of Fe dopants in Ni-deficit Ni3Al alloys

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

    V. N. Ivanovski; Umicevic, A.; Belosevic-Cavor, J.; Lei, Hechang; Li, Lijun; Cekic, B.; Koteski, V.; Petrovic, C.

    2015-08-24

    We found that the local electronic and magnetic structure, hyperfine interactions, and phase composition of polycrystalline Ni–deficient Ni 3-x FexAl (x = 0.18 and 0.36) were investigated by means of 57 Fe Mössbauer spectroscopy. The samples were characterized by X–ray diffraction and magnetization measurements. The ab initio calculations performed with the projector augmented wave method and the calculations of the energies of iron point defects were done to elucidate the electronic structure and site preference of Fe doped Ni 3 Al. Moreover, the value of calculated electric field gradient tensor Vzz=1.6 1021Vm-2 matches well with the results of Mössbauer spectroscopymore » and indicates that the Fe atoms occupy Ni sites.« less

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

    SciTech Connect (OSTI)

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

    2012-06-01

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

  10. Geometric and Electronic Structures of the Ni(I) and Methyl-Ni(III)

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

    Intermediates of Methyl-Coenzyme M Reductase 9 Geometric and Electronic Structures of the Ni(I) and Methyl-Ni(III) Intermediates of Methyl-Coenzyme M Reductase Methyl-coenzyme M reductase (MCR) from methanogenic archaea catalyzes the terminal step in biological methane synthesis. Using coenzyme B (CoBSH) as the two-electron donor, MCR reduces methyl-coenzyme M (methyl-SCoM) to form methane and the heterodisulfide product, CoBS-SCoM. MCR contains an essential redox active nickel tetrapyrrolic

  11. Transmutation-induced embrittlement of V-Ti-Ni and V-Ni alloys in HFIR

    SciTech Connect (OSTI)

    Ohnuki, S.; Takahashi, H.; Garner, F.A.; Pawel, J.E.

    1996-04-01

    Vanadium, V-1Ni, V-10Ti and V-10Ti-1Ni (at %) were irradiated in HFIR to doses ranging from 18 to 30 dpa and temperatures between 300 and 600C. Since the irradiation was conducted in a highly thermalized neutron spectrum without shielding against thermal neutrons, significant levels of chromium (15-22%) were formed by transmutation. The addition of such large chromium levels strongly elevated the ductile to brittle transition temperature. At higher irradiation temperatures radiation-induced segregation of transmutant Cr and solute Ti at specimen surfaces leads to strong increases in the density of the alloy.

  12. Microstructures in rapidly solidified Ni-Mo alloys

    SciTech Connect (OSTI)

    Jayaraman, N.; Tewari, S.N.; Hemker, K.J.; Glasgow, T.K.

    1985-01-01

    Ni-Mo alloys of compositions ranging from pure Ni to Ni-40 at % Mo were rapidly solidified by chill block melt spinning in vacuum and were examined by optical metallography, x-ray diffraction and transmission electron microscopy. Rapid solidification resulted in an extension of molybdenum solubility in nickel from 28 to 37.5 at %. A number of different phases and microstructures were seen at different depths (solidification conditions) from the quenched surface of the melt spun ribbons.

  13. Competition between Order and Phase Separation in Au-Ni

    SciTech Connect (OSTI)

    Reichert, H.; Schoeps, A.; Ramsteiner, I.B.; Bugaev, V.N.; Shchyglo, O.; Udyansky, A.; Dosch, H.; Asta, M.; Drautz, R.; Honkimaeki, V.

    2005-12-02

    We have measured and theoretically analyzed the diffuse scattering in the binary alloy system Au-Ni, which has been proposed as a testing ground for theories of alloy phase stability. We found strong evidence that in the alloys Au{sub 3}Ni and Au{sub 3}Ni{sub 2}, fluctuations of both ordering- and clustering-type are competing with each other. Our results resolve a long-standing controversy on the balance of relaxation and mixing energies in this alloy system and explain recent findings of ordering in thin Au-Ni films.

  14. Sources of stress gradients in electrodeposited Ni MEMS. (Conference...

    Office of Scientific and Technical Information (OSTI)

    Title: Sources of stress gradients in electrodeposited Ni MEMS. The ability of future integrated metal-semiconductor micro-systems such as RF MEMS to perform highly complex ...

  15. Numerical Simulation of Ni Grain Growth in a Thermal Gradient

    Office of Scientific and Technical Information (OSTI)

    665C Numerical Simulation of Ni Grain Growth in a Thermal Gradient Sandia National Laboratories John A. Mitchell and Veena Tikare Sandia National Laboratories, Albuquerque New ...

  16. Solid-Solution CrCoCuFeNi High-Entropy Alloy Thin Films Synthesized...

    Office of Scientific and Technical Information (OSTI)

    ... tion up to 800C,1-3 high yield strengths at elevated temperatures,4 high ... lowest surface energy planes are the 111 family of planes, which have been numerically ...

  17. American Flyers N-I Wine Makers

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

    Flyers N-I Wine Makers WSI leads charge in local bike events. NSTec recognizes top performers in NNSS mission. Navarro employees enjoy wine making hobby. See page 8. See page 7. Do You Know Where To Find Latest NNSS Info? In late August, a rainstorm in Las Vegas caused flooding near Mt. Charleston that washed the remnants of this summer's Carpenter Fire across U.S. 95, blocking the roadway. It was 11 p.m. on a Sunday night, and the road closure threatened Nevada National Security Site (NNSS)

  18. Energies of Electronic States of Ni (II) Ion in NiO-Al2O3 Catalyst Prepared by Impregnation

    SciTech Connect (OSTI)

    Obadovic, D. Z.; Kiurski, J.; Marinkovic-Neducin, R. P.

    2007-04-23

    The behavior of NiO-Al2O3 catalysts is strongly dependent on the preparation method, as well as on pretreatment conditions. In the present work we investigated the influences of Ni(II) ion on NiO-Al2O3 catalysts properties due to the preparation by impregnation method. Based on experimental diffuse reflectance spectroscopy (DRS) data of electronic d-d transitions of Ni (II) promoter ion the energies of electronic states in spinel-like structure were calculated, and the most probable scheme of molecular orbital have been proposed.

  19. Enhanced photocatalytic efficiency in zirconia buffered n-NiO/p-NiO single crystalline heterostructures by nanosecond laser treatment

    SciTech Connect (OSTI)

    Molaei, R.; Bayati, M. R.; Alipour, H. M.; Nori, S.; Narayan, J.

    2013-06-21

    We report the formation of NiO based single crystalline p-n junctions with enhanced photocatalytic activity induced by pulsed laser irradiation. The NiO epilayers were grown on Si(001) substrates buffered with cubic yttria-stabilized zirconia (c-YSZ) by using pulsed laser deposition. The NiO/c-YSZ/Si heterostructures were subsequently laser treated by 5 pulses of KrF excimer laser (pulse duration = 25 Multiplication-Sign 10{sup -9} s) at lower energies. Microstructural studies, conducted by X-ray diffraction ({theta}-2{theta} and {phi} techniques) and high resolution transmission electron microscope, showed a cube-on-cube epitaxial relationship at the c-YSZ/Si interface; the epitaxial relationship across the NiO/c-YSZ interface was established as NiO<111 > Double-Vertical-Line Double-Vertical-Line c-YSZ<001> and in-plane NiO<110> Double-Vertical-Line Double-Vertical-Line c-YSZ<100>. Electron microscopy studies showed that the interface between the laser annealed and the pristine region as well as the NiO/c-YSZ interface was atomically sharp and crystallographically continuous. The formation of point defects, namely oxygen vacancies and NiO, due to the coupling of the laser photons with the NiO epilayers was confirmed by XPS. The p-type electrical characteristics of the pristine NiO epilayers turned to an n-type behavior and the electrical conductivity was increased by one order of magnitude after laser treatment. Photocatalytic activity of the pristine (p-NiO/c-YSZ/Si) and the laser-annealed (n-NiO/p-NiO/c-YSZ/Si) heterostructures were assessed by measuring the decomposition rate of 4-chlorophenol under UV light. The photocatalytic reaction rate constants were determined to be 0.0059 and 0.0092 min{sup -1} for the as-deposited and the laser-treated samples, respectively. The enhanced photocatalytic efficiency was attributed to the suppressed charge carrier recombination in the NiO based p-n junctions and higher electrical conductivity. Besides, the oxygen vacancies

  20. Tunability of exchange bias in Ni@NiO core-shell nanoparticles obtained by sequential layer deposition

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

    D'Addato, Sergio; Spadaro, Maria Chiara; Luches, Paola; Valeri, Sergio; Grillo, Vincenzo; Rotunno, Enzo; Roldan Gutierrez, Manuel A.; Pennycook, Stephen J.; Ferretti, Anna Maria; Capetti, Elena; et al

    2015-01-01

    Films of magnetic Ni@NiO core–shell nanoparticles (NPs, core diameter d ≅ 12 nm, nominal shell thickness variable between 0 and 6.5 nm) obtained with sequential layer deposition were investigated, to gain insight into the relationships between shell thickness/morphology, core-shell interface, and magnetic properties. Different values of NiO shell thickness ts could be obtained while keeping the Ni core size fixed, at variance with conventional oxidation procedures where the oxide shell is grown at the expense of the core. Chemical composition, morphology of the as-produced samples and structural features of the Ni/NiO interface were investigated with x-ray photoelectron spectroscopy and microscopymore » (scanning electron microscopy, transmission electron microscopy) techniques, and related with results from magnetic measurements obtained with a superconducting quantum interference device. The effect of the shell thickness on the magnetic properties could be studied. The exchange bias (EB) field Hbias is small and almost constant for ts up to 1.6 nm; then it rapidly grows, with no sign of saturation. This behavior is clearly related to the morphology of the top NiO layer, and is mostly due to the thickness dependence of the NiO anisotropy constant. The ability to tune the EB effect by varying the thickness of the last NiO layer represents a step towards the rational design and synthesis of core–shell NPs with desired magnetic properties.« less

  1. Lanthanide Al-Ni base Ericsson cycle magnetic refrigerants

    DOE Patents [OSTI]

    Gschneidner, Jr., Karl A.; Takeya, Hiroyuki

    1995-10-31

    A magnetic refrigerant for a magnetic refrigerator using the Ericsson thermodynamic cycle comprises DyAlNi and (Gd.sub.0.54 Er.sub.0.46)AlNi alloys having a relatively constant .DELTA.Tmc over a wide temperature range.

  2. Lanthanide Al-Ni base Ericsson cycle magnetic refrigerants

    DOE Patents [OSTI]

    Gschneidner, K.A. Jr.; Takeya, Hiroyuki

    1995-10-31

    A magnetic refrigerant for a magnetic refrigerator using the Ericsson thermodynamic cycle comprises DyAlNi and (Gd{sub 0.54}Er{sub 0.46})AlNi alloys having a relatively constant {Delta}Tmc over a wide temperature range. 16 figs.

  3. Synthesis and electrochemical properties of NiO nanospindles

    SciTech Connect (OSTI)

    Zhou, Hai; Lv, Baoliang; Xu, Yao; Wu, Dong

    2014-02-01

    Graphical abstract: NiO nanospindles with a different electrochemical activity as compared to those previous reports were synthesized via an agglomeration–dissolution–recrystallization growth process without the addition of any surfactant. - Highlights: • NiO nanospindles were synthesized without the addition of any surfactant. • The agglomeration–dissolution–recrystallization growth process was used to explain the precursors’ formation process of the spindle-like NiO. • As-obtained spindle-like NiO showed a different electrochemical activity as compared to those previous reports. - Abstract: NiO nanospindles were successfully synthesized via a hydrothermal and post-treatment method. The as-synthesized nanospindles were about several hundred nanometers in width and about one micrometer in length. X-ray diffraction (XRD) analysis revealed that the spindle-like structure was cubic NiO phase crystalline. Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) analysis indicated that these NiO nanospindles were of single crystal nature. On the basis of time-dependent experiments, a possible agglomeration–dissolution–recrystallization growth process was proposed to explain the formation process of the spindle-like precursors. The cyclic voltammetry (CV) measurement showed that the as-prepared spindle-like NiO exhibited a pseudo-capacitance behavior.

  4. Ni/Pd core/shell nanoparticles supported on graphene as a highly...

    Office of Scientific and Technical Information (OSTI)

    NiPd coreshell nanoparticles supported on graphene as a highly active and reusable ... Citation Details In-Document Search Title: NiPd coreshell nanoparticles supported on ...

  5. SF6432-NI (02-01-12) Fixed Price Former Soviet Union

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

    Retrieve latest version electronically. SF 6432-NI (020112) SECTION II STANDARD TERMS ... 150,000 Control : SF 6432-NI Title: Standard Terms & Conditions for Fixed Price ...

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

    Office of Scientific and Technical Information (OSTI)

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

  7. Magnetic interactions in NiO at ultrahigh pressure

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

    Potapkin, Vasily; Dubrovinsky, Leonid; Sergueev, I.; Ekholm, M.; Kantor, Innokenty; Bessas, D.; Bykova, E.; Prakapenka, V.; Hermann, Raphael P.; Rueffer, Rudolf; et al

    2016-05-24

    Here, magnetic properties of NiO have been studied in the multimegabar pressure range by nuclear forward scattering of synchrotron radiation using the 67.4 keV M ssbauer transition of 61Ni. The observed magnetic hyperfine splitting confirms the antiferromagnetic state of NiO up to 280 GPa, the highest pressure where magnetism has been observed so far, in any material. Remarkably, the hyperfine field increases from 8.47 T at ambient pressure to ~24 T at the highest pressure, ruling out the possibility of a magnetic collapse. A joint x-ray diffraction and extended x-ray-absorption fine structure investigation reveals that NiO remains in a distortedmore » sodium chloride structure in the entire studied pressure range. Ab initio calculations support the experimental observations, and further indicate a complete absence of Mott transition in NiO up to at least 280 GPa.« less

  8. Photosensitivity of the Ni-n-GaAs Schottky barriers

    SciTech Connect (OSTI)

    Melebaev, D.; Melebaeva, G. D.; Rud', V. Yu. Rud', Yu. V.

    2009-01-15

    The method of chemical deposition is used to form the structures with the Ni-n-GaAs Schottky barrier. The thickness of the Ni layers with a specular outer surface was varied within the range of 150-220 A. It was experimentally observed for the first time that photosensitivity of the obtained barriers with the semitransparent Ni layers illuminated is practically absent in the Fowler region of the spectrum at hv = 0.9-1.5 eV. This circumstance is related mainly to the fact that, in this case, the Ni layer side of the structure was illuminated, and radiation with the photon energy hv < 1.3 eV was effectively reflected from the nickel surface. It is established that the developed Ni-n-GaAs structures can be used as high-efficiency wide-band photoconverters of both visible and ultraviolet radiation.

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

    SciTech Connect (OSTI)

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

    2014-08-01

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

  10. Enhanced Dry Reforming of Methane on Ni and Ni-Pt Catalysts Synthesized by Atomic Layer Deposition

    SciTech Connect (OSTI)

    Gould, Troy D.; Montemore, Matthew M.; Lubers, Alia M.; Ellis, Lucas D.; Weimer, Alan; Falconer, John L.; Medlin, James W.

    2015-02-25

    Atomic layer deposition (ALD) was used to deposit Ni and Pt on alumina supports to form monometallic and bimetallic catalysts with initial particle sizes of 12.4 nm. The ALD catalysts were more active (per mass of metal) than catalysts prepared by incipient wetness (IW) for dry reforming of methane (DRM), and they did not form carbon whiskers during reaction due to their sufficiently small size. Catalysts modified by Pt ALD had higher rates of reaction per mass of metal and inhibited coking, whereas NiPt catalysts synthesized by IW still formed carbon whiskers. Temperature-programmed reduction of Ni catalysts modified by Pt ALD indicated the presence of bimetallic interaction. Density functional theory calculations suggested that under reaction conditions, the NiPt surfaces form Ni-terminated surfaces that are associated with higher DRM rates (due to their C and O adsorption energies, as well as the CO formation and CH4 dissociation energies).

  11. The first principle study of Ni{sub 2}ScGa and Ni{sub 2}TiGa

    SciTech Connect (OSTI)

    zduran, Mustafa; Turgut, Kemal; Arikan, Nihat; ?yigr, Ahmet; Candan, Abdullah

    2014-10-06

    We computed the electronic structure, elastic moduli, vibrational properties, and Ni{sub 2}TiGa and Ni{sub 2}ScGa alloys in the cubic L2{sub 1} structure. The obtained equilibrium lattice constants of these alloys are in good agreement with available data. In cubic systems, there are three independent elastic constants, namely C{sub 11}, C{sub 12} and C{sub 44}. We calculated elastic constants in L2{sub 1} structure for Ni{sub 2}TiGa and Ni{sub 2}ScGa using the energy-strain method. The electronic band structure, total and partial density of states for these alloys were investigated within density functional theory using the plane-wave pseudopotential method implemented in Quantum-Espresso program package. From band structure, total and projected density of states, we observed metallic characters of these compounds. The electronic calculation indicate that the predominant contributions of the density of states at Fermi level come from the Ni 3d states and Sc 3d states for Ni{sub 2}TiGa, Ni 3d states and Sc 3d states for Ni{sub 2}ScGa. The computed density of states at Fermi energy are 2.22 states/eV Cell for Ni{sub 2}TiGa, 0.76 states/eV Cell for Ni{sub 2}ScGa. The vibrational properties were obtained using a linear response in the framework at the density functional perturbation theory. For the alloys, the results show that the L2{sub 1} phase is unstable since the phonon calculations have imagine modes.

  12. Can Ni phosphides become viable hydroprocessing catalysts?

    SciTech Connect (OSTI)

    Soled, S.; Miseo, S.; Baumgartner, J.; Guzman, J.; Bolin, T.; Meyer, R.

    2015-05-15

    We prepared higher surface area nickel phosphides than are normally found by reducing nickel phosphate. To do this, we hydrothermally synthesized Ni hydroxy phosphite precursors with low levels of molybdenum substitution. The molybdenum substitution increases the surface area of these precursors. During pretreatment in a sulfiding atmosphere (such as H2S/H2) dispersed islands of MoS2 segregate from the precursor and provide a pathway for H2 dissociation that allows reduction of the phosphite precursor to nickel phosphide at substantially lower temperatures than in the absence of MoS2. The results reported here show that to create nickel phosphides with comparable activity to conventional supported sulfide catalysts, one would have to synthesize the phosphide with surface areas exceeding 400 m2/g (i.e. with nanoparticles less than 30 Å in lateral dimension).

  13. Ni/metal hydride secondary element

    DOE Patents [OSTI]

    Bauerlein, Peter

    2005-04-19

    A Ni/metal hydride secondary element having a positive nickel hydroxide electrode, a negative electrode having a hydrogen storage alloy, and an alkaline electrolyte, the positive electrode, provided with a three-dimensional metallic conductive structure, also contains an aluminum compound which is soluble in the electrolyte, in addition to nickel hydroxide and cobalt oxide. The aluminum compound is aluminum hydroxide and/or aluminum oxide, and the mass of the aluminum compound which is present in the positive bulk material mixture is 0.1 to 2% by weight relative to the mass of the nickel hydroxide which is present. In combination with aluminum hydroxide or aluminum oxide, the positive electrode further contains lanthanoid oxidic compounds Y.sub.2 O.sub.3, La.sub.2 O.sub.3 and Ca(OH).sub.2, as well as mixtures of these compounds.

  14. Phase equilibria, formation, crystal and electronic structure of ternary compounds in Ti-Ni-Sn and Ti-Ni-Sb ternary systems

    SciTech Connect (OSTI)

    Romaka, V.V.; Rogl, P.; Romaka, L.; Stadnyk, Yu.; Melnychenko, N.; Grytsiv, A.; Falmbigl, M.; Skryabina, N.

    2013-01-15

    The phase equilibria of the Ti-Ni-Sn and Ti-Ni-Sb ternary systems have been studied in the whole concentration range by means of X-ray and EPM analyses at 1073 K and 873 K, respectively. Four ternary intermetallic compounds TiNiSn (MgAgAs-type), TiNi{sub 2-x}Sn (MnCu{sub 2}Al-type), Ti{sub 2}Ni{sub 2}Sn (U{sub 2}Pt{sub 2}Sn-type), and Ti{sub 5}NiSn{sub 3} (Hf{sub 5}CuSn{sub 3}-type) are formed in Ti-Ni-Sn system at 1073 K. The TiNi{sub 2}Sn stannide is characterized by homogeneity in the range of 50-47 at% of Ni. The Ti-Ni-Sb ternary system at 873 K is characterized by formation of three ternary intermetallic compounds, Ti{sub 0.8}NiSb (MgAgAs-type), Ti{sub 5}Ni{sub 0.45}Sb{sub 2.55} (W{sub 5}Si{sub 3}-type), and Ti{sub 5}NiSb{sub 3} (Hf{sub 5}CuSn{sub 3}-type). The solubility of Ni in Ti{sub 0.8}NiSb decreases number of vacancies in Ti site up to Ti{sub 0.91}Ni{sub 1.1}Sb composition. - Graphical abstract: Isothermal section of the Ti-Ni-Sn phase diagram and DOS distribution in hypothetical TiNi{sub 1+x}Sn solid solution. Highlights: Black-Right-Pointing-Pointer Ti-Ni-Sn phase diagram was constructed at 1073 K. Black-Right-Pointing-Pointer Four ternary compounds are formed: TiNiSn, TiNi{sub 2-x}Sn, Ti{sub 2}Ni{sub 2}Sn, and Ti{sub 5}NiSn{sub 3}. Black-Right-Pointing-Pointer Three ternary compounds exist in Ti-Ni-Sb system at 873 K. Black-Right-Pointing-Pointer The TiNi{sub 2}Sb compound is absent.

  15. The fabrication of foam-like 3D mesoporous NiO-Ni as anode for high performance Li-ion batteries

    SciTech Connect (OSTI)

    Huang, Peng; Zhang, Xin; Wei, Jumeng; Pan, Jiaqi; Sheng, Yingzhou; Feng, Boxue

    2015-03-15

    Graphical abstract: Foam-like 3 dimensional (3D) mesoporous NiO on 3D micro-porous Ni was fabricated. - Highlights: We prepare NiO-Ni foam composite via hydrothermal etching and subsequent annealing. The NiO exhibits novel foam-like 3D mesoporous architecture. The NiO-Ni anode shows good cycle stability. - Abstract: Foam-like three dimensional mesoporous NiO on Ni foam was fabricated via facile hydrothermal etching and subsequent annealing treatment. The porous NiO consists of a large number of nanosheets with mean thickness about 50 nm, among which a large number of mesoscopic pores with size ranges from 100 nm to 1 ?m distribute. The electrochemical performance of the as-prepared NiO-Ni as anode for lithium ion battery was studied by conventional charge/discharge test, which shows excellent cycle stability and rate capability. It exhibits initial discharge and charge capacities of 979 and 707 mA h g{sup ?1} at a charge/discharge rate of 0.7 C, which maintain of 747 and 738 mA h g{sup ?1} after 100 cycles. Even after 60 cycles at various rates from 0.06 to 14 C, the 10th discharge and charge capacities of the NiO-Ni electrode can revert to 699 and 683 mA h g{sup ?1} when lowering the charge/discharge rate to 0.06 C.

  16. Nondestructive evaluation of Ni-Ti shape memory alloy

    SciTech Connect (OSTI)

    Meir, S.; Gordon, S.; Karsh, M.; Ayers, R.; Olson, D. L.; Wiezman, A.

    2011-06-23

    The nondestructive evaluation of nickel titanium (Ni-Ti) alloys for applications such as heat treatment for biomaterials applications (dental) and welding was investigated. Ni-Ti alloys and its ternary alloys are valued for mechanical properties in addition to the shape memory effect. Two analytical approaches were perused in this work. Assessment of the microstructure of the alloy that determines the martensitic start temperature (Ms) of Ni-Ti alloy as a function of heat treatment, and secondly, an attempt to evaluate a Friction Stir Welding, which involves thermo-mechanical processing of the alloy.

  17. Graphene Monolayer Rotation on Ni(111) Facilities Bilayer Graphene Growth

    SciTech Connect (OSTI)

    Batzill M.; Sutter P.; Dahal, A.; Addou, R.

    2012-06-11

    Synthesis of bilayer graphene by chemical vapor deposition is of importance for graphene-based field effect devices. Here, we demonstrate that bilayer graphene preferentially grows by carbon-segregation under graphene sheets that are rotated relative to a Ni(111) substrate. Rotated graphene monolayer films can be synthesized at growth temperatures above 650 C on a Ni(111) thin-film. The segregated second graphene layer is in registry with the Ni(111) substrate and this suppresses further C-segregation, effectively self-limiting graphene formation to two layers.

  18. Overall Photocatalytic Water Splitting with NiOx-SrTiO3 A Revised Mechanism

    SciTech Connect (OSTI)

    Townsend, Troy K.; Browning, Nigel D.; Osterloh, Frank

    2012-11-01

    NiOx (0 < x < 1) modified SrTiO3 (STO) is one of the best studied photocatalyst for overall water splitting under UV light. The established mechanism for this and many other NiOx containing catalysts assumes water oxidation to occur at the early transition metal oxide and water reduction at NiOx. Here we show that NiOx-STO is more likely a three component Ni-STO-NiO catalyst, in which STO absorbs the light, Ni reduces protons, and NiO oxidizes water. This interpretation is based on systematic H2/O2 evolution tests of appropriately varied catalyst compositions using oxidized, chemically and photochemically added nickel and NiO nanoparticle cocatalysts. Surface photovoltage (SPV) measurements reveal that Ni(0) serves as an electron trap (site for water reduction) and that NiO serves as a hole trap (site for water oxidation). Electrochemical measurements show that the overpotential for water oxidation correlates with NiO content, whereas the water reduction overpotential depends on Ni content. Photodeposition experiments with NiCl2 and H2PtCl6 on NiO-STO show that electrons are available on the STO surface, not on the NiO particles. Based on photoelectrochemistry, both NiO and Ni particles suppress the Fermi level in STO, but the effect of this shift on catalytic activity is not clear. Overall, the results suggest a revised role for NiO in NiOx-STO and in many other nickel-containing water splitting systems, including NiOx-La:KTaO3, and many layered perovskites.

  19. Application of cluster-plus-glue-atom model to barrierless CuNiTi and CuNiTa films

    SciTech Connect (OSTI)

    Li, Xiaona, E-mail: lixiaona@dlut.edu.cn; Ding, Jianxin; Wang, Miao; Dong, Chuang [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024 (China); Chu, Jinn P. [Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China)

    2014-11-01

    To improve the thermal stability of copper and avoid its diffusion into surrounding dielectrics or interfacial reactions with them, the authors applied the cluster-plus-glue-atom model to investigate barrierless CuNiM (M?=?Ti or Ta) seed layers. The dissolution of the third element (Ti or Ta) in the Cu lattice with the aid of Ni significantly improved the thermal stability of the Cu seed layer. The appropriate M/Ni (M?=?Ti or Ta) ratio was selected to obtain a low resistivity: the resistivity was as low as 2.5??? cm for the (Ti{sub 1.5/13.5}Ni{sub 12/13.5}){sub 0.3}Cu{sub 99.7} film and 2.8??? cm for the (Ta{sub 1.1/13.1}Ni{sub 12/13.1}){sub 0.4}Cu{sub 99.6} film after annealing at 500?C for 1?h. After annealing at 500?C for 40?h, the two films remained stable without forming a Cu{sub 3}Si compound. The authors confirmed that the range of applications of the cluster-plus-glue-atom model could be extended. Therefore, a third element M with negative enthalpies of mixing with both Cu and Ni could be selected, under the premise that the mixing enthalpy of MNi is more negative than that of MCu.

  20. Excess Ni-doping induced enhanced room temperature magneto-functionality in Ni-Mn-Sn based shape memory alloy

    SciTech Connect (OSTI)

    Pramanick, S.; Giri, S.; Majumdar, S.; Chatterjee, S.

    2014-09-15

    Present work reports on the observation of large magnetoresistance (??30% at 80 kOe) and magnetocaloric effect (?12?Jkg{sup ?1}K{sup ?1} for 050 kOe) near room temperature (?290?K) on the Ni-excess ferromagnetic shape memory alloy Ni{sub 2.04}Mn{sub 1.4}Sn{sub 0.56}. The sample can be thought of being derived from the parent Ni{sub 2}Mn{sub 1.4}Sn{sub 0.6} alloy, where excess Ni was doped at the expense of Sn. Such Ni doping enhances the martensitic transition temperature and for the Ni{sub 2.04}Mn{sub 1.4}Sn{sub 0.56} it is found to be optimum (288?K). The doped alloy shows enhanced magneto-functional properties as well as reduced saturation magnetization as compared to the undoped counterpart at low temperature. A probable increment of antiferromagnetic correlation between Mn-atoms on Ni substitution can be accounted for the enhanced magneto-functional properties as well as reduction in saturation moment.

  1. Tunability of exchange bias in Ni@NiO core-shell nanoparticles obtained by sequential layer deposition

    SciTech Connect (OSTI)

    D'Addato, Sergio; Spadaro, Maria Chiara; Luches, Paola; Valeri, Sergio; Grillo, Vincenzo; Rotunno, Enzo; Roldan Gutierrez, Manuel A.; Pennycook, Stephen J.; Ferretti, Anna Maria; Capetti, Elena; Ponti, A.

    2015-01-01

    Films of magnetic Ni@NiO core–shell nanoparticles (NPs, core diameter d ≅ 12 nm, nominal shell thickness variable between 0 and 6.5 nm) obtained with sequential layer deposition were investigated, to gain insight into the relationships between shell thickness/morphology, core-shell interface, and magnetic properties. Different values of NiO shell thickness ts could be obtained while keeping the Ni core size fixed, at variance with conventional oxidation procedures where the oxide shell is grown at the expense of the core. Chemical composition, morphology of the as-produced samples and structural features of the Ni/NiO interface were investigated with x-ray photoelectron spectroscopy and microscopy (scanning electron microscopy, transmission electron microscopy) techniques, and related with results from magnetic measurements obtained with a superconducting quantum interference device. The effect of the shell thickness on the magnetic properties could be studied. The exchange bias (EB) field Hbias is small and almost constant for ts up to 1.6 nm; then it rapidly grows, with no sign of saturation. This behavior is clearly related to the morphology of the top NiO layer, and is mostly due to the thickness dependence of the NiO anisotropy constant. The ability to tune the EB effect by varying the thickness of the last NiO layer represents a step towards the rational design and synthesis of core–shell NPs with desired magnetic properties.

  2. [NiIII(OMe)]-mediated reductive activation of CO2 affording a Ni(κ1-OCO) complex

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

    Chiou, Tzung -Wen; Tseng, Yen -Ming; Lu, Tsai -Te; Weng, Tsu -Chien; Sokaras, Dimosthenes; Ho, Wei -Chieh; Kuo, Ting -Shen; Jang, Ling -Yun; Lee, Jyh -Fu; Liaw, Wen -Feng

    2016-02-24

    Here, carbon dioxide is expected to be employed as an inexpensive and potential feedstock of C1 sources for the mass production of valuable chemicals and fuel. Versatile chemical transformations of CO2, i.e. insertion of CO2 producing bicarbonate/acetate/formate, cleavage of CO2 yielding μ-CO/μ-oxo transition-metal complexes, and electrocatalytic reduction of CO2 affording CO/HCOOH/CH3OH/CH4/C2H4/oxalate were well documented. Herein, we report a novel pathway for the reductive activation of CO2 by the [NiIII(OMe)(P(C6H3-3-SiMe3-2-S)3)]– complex, yielding the [NiIII(κ1-OCO˙–)(P(C6H3-3-SiMe3-2-S)3)]– complex. The formation of this unusual NiIII(κ1-OCO˙–) complex was characterized by single-crystal X-ray diffraction, EPR, IR, SQUID, Ni/S K-edge X-ray absorption spectroscopy, and Ni valence-to-core X-ray emissionmore » spectroscopy. The inertness of the analogous complexes [NiIII(SPh)], [NiII(CO)], and [NiII(N2H4)] toward CO2, in contrast, demonstrates that the ionic [NiIII(OMe)] core attracts the binding of weak σ-donor CO2 and triggers the subsequent reduction of CO2 by the nucleophilic [OMe]– in the immediate vicinity. This metal–ligand cooperative activation of CO2 may open a novel pathway promoting the subsequent incorporation of CO2 in the buildup of functionalized products.« less

  3. Ni(NiO)/single-walled carbon nanotubes composite: Synthesis of electro-deposition, gas sensing property for NO gas and density functional theory calculation

    SciTech Connect (OSTI)

    Li, Li; Zhang, Guo; Chen, Lei; Bi, Hong-Mei; Shi, Ke-Ying

    2013-02-15

    Graphical abstract: The Ni(NiO)/semiconducting single-walled carbon nanotubes composite collected from the cathode after electro-deposition shows a high sensitivity to low-concentration NO gas at room temperature (18 C). Display Omitted Highlights: ? Ni(NiO) nanoparticles were deposited on semiconducting SWCNTs by electro-deposition. ? Ni(NiO)/semiconducting SWCNTs film shows a high sensitivity to NO gas at 18 C. ?Theoretical calculation reveals electron transfer from SWCNTs to NO via Ni. -- Abstract: Single-walled carbon nanotubes which contains metallic SWCNTs (m-SWCNTs) and semiconducting SWCNTs (s-SWCNTs) have been obtained under electric arc discharge. Their separation can be effectively achieved by the electro-deposition method. The Ni(NiO)/s-SWCNTs composite was found on cathode where Ni was partially oxidized to NiO at ambient condition with Ni(NiO) nanoparticles deposited uniformly on the bundles of SWCNTs. These results were confirmed by Raman spectra, transmission electron microscopy (TEM), scanning electron microscopy (SEM), UVvisNIR and TG characterizations. Furthermore, investigation of the gas sensing property of Ni(NiO)/s-SWCNTs composite film to NO gas at 18 C demonstrated the sensitivity was approximately 5% at the concentration of 97 ppb. Moreover, density functional theory (DFT) calculations were performed to explore the sensing mechanism which suggested the adsorption of NO molecules onto the composite through NNi interaction as well as the proposition of electron transfer mechanisms from SWCNTs to NO via the Ni medium.

  4. Support effects on hydrotreating activity of NiMo catalysts

    SciTech Connect (OSTI)

    Dominguez-Crespo, M.A. Arce-Estrada, E.M.; Torres-Huerta, A.M.

    2007-10-15

    The effect of the gamma alumina particle size on the catalytic activity of NiMoS{sub x} catalysts prepared by precipitation method of aluminum acetate at pH = 10 was studied. The structural characterization of the supports was measured by using XRD, pyridine FTIR-TPD and nitrogen physisorption. NiMo catalysts were characterized during the preparation steps (annealing and sulfidation) using transmission electron microscopy (TEM). Hydrogen TPR studies of the NiMo catalysts were also carried out in order to correlate their hydrogenating properties and their catalytic functionality. Catalytic tests were carried out in a pilot plant at 613, 633 and 653 K temperatures. The results showed that the rate constants of hydrodesulfurization (HDS), hydrodenitrogenation (HDN) and hydrodearomatizing (HDA) at 613-653 K decreased in the following order: A > B > C corresponding to the increase of NiMoS particle size associated to these catalysts.

  5. Oxidation-resistant, solution-processed plasmonic Ni nanochain...

    Office of Scientific and Technical Information (OSTI)

    Oxidation-resistant, solution-processed plasmonic Ni nanochain-SiOsub x (x < 2) selective solar thermal absorbers Citation Details In-Document Search Title: Oxidation-resistant, ...

  6. Interdiffusion in nanometric Fe/Ni multilayer films

    SciTech Connect (OSTI)

    Liu, JX; Barmak, K

    2015-03-01

    Fe (3.1 nm)/Ni (3.3 nm)](20) multilayer films were prepared by DC magnetron sputtering onto oxidized Si(100) substrates. The Fe and Ni layers were shown to both be face-centered cubic by x-ray diffraction. Interdiffusion of the Fe and Ni layers in the temperature range of 300-430 degrees C was studied by x-ray reflectivity. From the decay of the integral intensity of the superlattice peak, the activation energy and the pre-exponential term for the effective interdiffusion coefficient were determined as to 1.06 +/- 0.07 eV and 5 x 10(-10) cm(2)/s, respectively. The relevance of the measured interdiffusion coefficient to the laboratory timescale synthesis of L1(0) ordered FeNi as a rare-earth free permanent magnet is discussed. (C) 2015 American Vacuum Society.

  7. N"I. L-S- Rad. Mat. DU

    Office of Legacy Management (LM)

    N"I. L-S- Rad. Mat. DU DU (UF4) Enr. U. Norm. U Thorium 34 Ti Alloy Subtotals Commercial ... Nuclear 1063- 570 1,484,083.2 14' Thorium Bridge- port Brass 762 380 -o- -o- 380 ...

  8. Double dumbbell shaped AgNi alloy by pulsed electrodeposition

    SciTech Connect (OSTI)

    Dhanapal, K.; Vasumathi, M.; Santhi, Kalavathy; Narayanan, V. Stephen, A.

    2014-01-28

    Silver-Nickel is the well-known thermally immiscible system that makes them quite complex for the formation of alloy. This kind of alloy can be attained from electrodeposition method. In the present work, AgNi alloy was synthesized by pulsed electrodeposition in a single bath two electrode system with the use of anodic alumina membrane. The prepared AgNi alloy and pure Ag were characterized with X-ray Diffraction (XRD) for structural confirmation, Scanning Electron Microscopy (SEM) for morphological, and magnetic properties by Vibrating Sample Magnetometer, respectively. The X-ray Diffraction study shows the formation of cubic structure for pure Ag. SEM analysis reveals the double dumbbell morphology for AgNi alloy and spherically agglomeration for pure silver. Hysteresis behaviour from VSM measurement indicates that the AgNi alloy have good ferro-magnetic properties.

  9. Anomalous magnetic behavior in nanocomposite materials of reduced graphene oxide-Ni/NiFe{sub 2}O{sub 4}

    SciTech Connect (OSTI)

    Kollu, Pratap E-mail: anirmalagrace@vit.ac.in; Prathapani, Sateesh; Varaprasadarao, Eswara K.; Mallick, Sudhanshu; Bahadur, D. E-mail: anirmalagrace@vit.ac.in; Santosh, Chella; Grace, Andrews Nirmala E-mail: anirmalagrace@vit.ac.in

    2014-08-04

    Magnetic Reduced Graphene Oxide-Nickel/NiFe{sub 2}O{sub 4} (RGO-Ni/NF) nanocomposite has been synthesized by one pot solvothermal method. Respective phase formations and their purities in the composite are confirmed by High Resolution Transmission Electron Microscope and X Ray Diffraction, respectively. For the RGO-Ni/NF composite material finite-size effects lead to the anomalous magnetic behavior, which is corroborated in temperature and field dependent magnetization curves. Here, we are reporting the behavior of higher magnetization values for Zero Field Cooled condition to that of Field Cooled for the RGO-Ni/NF nanocomposite. Also, the observed negative and positive moments in Hysteresis loops at relatively smaller applied fields (100?Oe and 200?Oe) are explained on the basis of surface spin disorder.

  10. Corrosion behavior of Ni and Ni-based alloys in concentrated NaOH solutions at high temperatures

    SciTech Connect (OSTI)

    Yasuda, M.; Fukumoto, K.; Ogata, Y.; Hine, F.

    1988-12-01

    Corrosion behavior of SUS 310S austenitic stainless steel, Alloy 600, Monel 400, and Ni 200 and NaOH solutions in the concentration range 30-60% at high temperatures up to 166/sup 0/C was studied. In solutions containing dissolved oxygen or under oxidizing conditions, all the specimens examined were corroded seriously due to oxygen diffusion through the porous oxide layer consisting of ..beta..-Ni(OH)/sub 2/. In hydrogen-saturated solutions, on the other hand, these Ni alloys were corrosion resistant because nickel in the alloys was active to oxidation of hydrogen. The specimens were corroded by deaerated solution at high temperatures in which hydrogen evolution took place as the counterreaction. The corrosion rate controlled by the hydrogen formation reaction increased exponentially with the decrease of the Ni content in the alloy.

  11. Crystal structure of Tb5Ni2In4, and magnetic properties of Dy5Ni2In4...

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Search Results Journal Article: Crystal structure of Tb5Ni2In4, and ... DOE Contract Number: DE-AC02-07CH11358 Resource Type: Journal Article Resource Relation: ...

  12. Electronic and structural influence of Ni by Pd substitution on the hydrogenation properties of TiNi

    SciTech Connect (OSTI)

    Emami, Hoda; Souques, Raphaeel; Crivello, Jean-Claude; Cuevas, Fermin

    2013-02-15

    In Ti (Ni,Pd) compounds, the hydrogen capacity and the stability of their hydrides decreases when Ni is partially substituted by larger in size Pd atoms. To understand this peculiar behaviour, the crystal structure of TiNi{sub 1-x}Pd{sub x}D{sub y} (x=0.1, 0.3 and 0.5) deuterides and the stability of TiNi{sub 1-x}Pd{sub x} (0{<=}x{<=}0.5) intermetallics and their hydrides have been investigated by both neutron diffraction experiments and Density Functional Theory (DFT) calculations. Neutron diffraction shows that at x=0.1 and 0.3, deuterium absorption induces tetragonal distortion in intermetallics sublattice whereas at x=0.5 the cubic symmetry is preserved. The structural properties and the heat of formation of TiNi{sub 1-x}Pd{sub x} (0{<=}x{<=}0.5) intermetallics and their hydrides have been determined by DFT. These results show that Pd substitution increases the stability of the intermetallics and decreases the stability of the hydrides, which confirms the rule of reverse stability. - Graphical abstract: Crystal structure of Ti(Ni,Pd)Hy hydrides in the I4/mmm space group. Highlights: Black-Right-Pointing-Pointer Neutron Diffraction and DFT calculations have been done on TiNi{sub 1-x}Pd{sub x}H{sub y} compounds. Black-Right-Pointing-Pointer Electronic effect of Pd substitution governs the hydrogenation properties in TiNi. Black-Right-Pointing-Pointer The rule of reverse stability in intermetallics/hydrides is observed with Pd substitution. Black-Right-Pointing-Pointer The hydrogen atoms in the I4/mmm structure prefer to occupy the 16n site.

  13. SANDIA COKPOK4TION SANDIA BASE, .QLDUQUERQUE. N. M.

    Office of Legacy Management (LM)

    F. k e r s , R. F. Beers, Inc. S. E . J e r m e , Univ. of Nev., Xeno %. L, B r m e , i h z e l t o n Nuclear Science Corp. 0. R. P l a c k , USPXS, Las Vegas, Nev. G. H. H i g ...

  14. Direct Observation of Defect Range and Evolution in Ion-Irradiated Single Crystalline Ni and Ni Binary Alloys

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

    Lu, Chenyang; Jin, Ke; Béland, Laurent K.; Zhang, Feifei; Yang, Taini; Qiao, Liang; Zhang, Yanwen; Bei, Hongbin; Christen, Hans M.; Stoller, Roger E.; et al

    2016-02-01

    We report that energetic ions have been widely used to evaluate the irradiation tolerance of structural materials for nuclear power applications and to modify material properties. It is important to understand the defect production, annihilation and migration mechanisms during and after collision cascades. In this study, single crystalline pure nickel metal and single-phase concentrated solid solution alloys of 50%Ni50%Co (NiCo) and 50%Ni50%Fe (NiFe) without apparent preexisting defect sinks were employed to study defect dynamics under ion irradiation. Both cross-sectional transmission electron microscopy characterization (TEM) and Rutherford backscattering spectrometry channeling (RBS-C) spectra show that the range of radiation-induced defect clusters farmore » exceed the theoretically predicted depth in all materials after high-dose irradiation. Defects in nickel migrate faster than in NiCo and NiFe. Both vacancy-type stacking fault tetrahedra (SFT) and interstitial loops coexist in the same region, which is consistent with molecular dynamics simulations. Kinetic activation relaxation technique (k-ART) simulations for nickel showed that small vacancy clusters, such as di-vacancies and tri-vacancies, created by collision cascades are highly mobile, even at room temperature. The slower migration of defects in the alloy along with more localized energy dissipation of the displacement cascade may lead to enhanced radiation tolerance.« less

  15. Enhanced room temperature ferromagnetism in antiferromagnetic NiO nanoparticles

    SciTech Connect (OSTI)

    Ravikumar, Patta; Kisan, Bhagaban; Perumal, A.

    2015-08-15

    We report systematic investigations of structural, vibrational, resonance and magnetic properties of nanoscale NiO powders prepared by ball milling process under different milling speeds for 30 hours of milling. Structural properties revealed that both pure NiO and as-milled NiO powders exhibit face centered cubic structure, but average crystallite size decreases to around 11 nm along with significant increase in strain with increasing milling speed. Vibrational properties show the enhancement in the intensity of one-phonon longitudinal optical (LO) band and disappearance of two-magnon band due to size reduction. In addition, two-phonon LO band exhibits red shift due to size-induced phonon confinement effect and surface relaxation. Pure NiO powder exhibit antiferromagnetic nature, which transforms into induced ferromagnetic after size reduction. The average magnetization at room temperature increases with decreasing the crystallite size and a maximum moment of 0.016 μ{sub B}/f.u. at 12 kOe applied field and coercivity of 170 Oe were obtained for 30 hours milled NiO powders at 600 rotation per minute milling speed. The change in the magnetic properties is also supported by the vibrational properties. Thermomagnetization measurements at high temperature reveal a well-defined magnetic phase transition at high temperature (T{sub C}) around 780 K due to induced ferromagnetic phase. Electron paramagnetic resonance (EPR) studies reveal a good agreement between the EPR results and magnetic properties. The observed results are described on the basis of crystallite size variation, defect density, large strain, oxidation/reduction of Ni and interaction between uncompensated surfaces and particle core with lattice expansion. The obtained results suggest that nanoscale NiO powders with high T{sub C} and moderate magnetic moment at room temperature with cubic structure would be useful to expedite for spintronic devices.

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

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

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

  17. Modified Ni-Cu catalysts for ethanol steam reforming

    SciTech Connect (OSTI)

    Dan, M.; Mihet, M.; Almasan, V.; Borodi, G.; Katona, G.; Muresan, L.; Lazar, M. D.

    2013-11-13

    Three Ni-Cu catalysts, having different Cu content, supported on γ-alumina were synthesized by wet co-impregnation method, characterized and tested in the ethanol steam reforming (ESR) reaction. The catalysts were characterized for determination of: total surface area and porosity (N{sub 2} adsorption - desorption using BET and Dollimer Heal methods), Ni surface area (hydrogen chemisorption), crystallinity and Ni crystallites size (X-Ray Diffraction), type of catalytic active centers (Hydrogen Temperature Programmed Reduction). Total surface area and Ni crystallites size are not significantly influenced by the addition of Cu, while Ni surface area is drastically diminished by increasing of Cu concentration. Steam reforming experiments were performed at atmospheric pressure, temperature range 150-350°C, and ethanol - water molar ration of 1 at 30, using Ar as carrier gas. Ethanol conversion and hydrogen production increase by the addition of Cu. At 350°C there is a direct connection between hydrogen production and Cu concentration. Catalysts deactivation in 24h time on stream was studied by Transmission Electron Microscopy (TEM) and temperature-programmed reduction (TPR) on used catalysts. Coke deposition was observed at all studied temperatures; at 150°C amorphous carbon was evidenced, while at 350°C crystalline, filamentous carbon is formed.

  18. An Update on NiCE Support for BISON

    SciTech Connect (OSTI)

    McCaskey, Alex; Billings, Jay Jay; Deyton, Jordan H.; Wojtowicz, Anna

    2015-09-01

    The Nuclear Energy Advanced Modeling and Simulation program (NEAMS) from the Department of Energy s Office of Nuclear Energy has funded the development of a modeling and simulation workflow environment to support the various codes in its nuclear energy scientific computing toolkit. This NEAMS Integrated Computational Environment (NiCE) provides extensible tools and services that enable efficient code execution, input generation, pre-processing visualizations, and post-simulation data analysis and visualization for a large portion of the NEAMS Toolkit. A strong focus for the NiCE development team throughout FY 2015 has been support for the Multiphysics Object Oriented Simulation Environment (MOOSE) and the NEAMS nuclear fuel performance modeling application built on that environment, BISON. There is a strong desire in the program to enable and facilitate the use of BISON throughout nuclear energy research and industry. A primary result of this desire is the need for strong support for BISON in NiCE. This report will detail improvements to NiCE support for BISON. We will present a new and improved interface for interacting with BISON simulations in a variety of ways: (1) improved input model generation, (2) embedded mesh and solution data visualizations, and (3) local and remote BISON simulation launch. We will also show how NiCE has been extended to provide support for BISON code development.

  19. Superior performance of Ni-W-Ce mixed-metal oxide catalysts for ethanol steam reforming: Synergistic effects of W- and Ni-dopants

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

    Rodriguez, Jose A.; Liu, Zongyuan; Xu, Wenqian; Yao, Siyu; Johnson-Peck, Aaron C.; Zhao, Fuzhen; Michorczyk, Piotr; Kubacka, Anna; Stach, Eric A.; Fernandez-Garica, Marcos; et al

    2014-11-26

    The ethanol steam reforming (ESR) reaction was studied over a series of Ni-W-Ce oxide catalysts. The structures of the catalysts were characterized using in-situ techniques including X-ray diffraction, Pair Distribution Function, X-ray absorption fine structure and transmission electron microscopy; while possible surface intermediates for the ESR reaction were investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy. In these materials, all the W and part of the Ni were incorporated into the CeO? lattice, with the remaining Ni forming highly dispersed nano NiO (moreThe Ni-W-Ce systeme exhibited a much larger lattice strain than those seen for Ni-Ce and W-Ce. Synergistic effects between Ni and W inside ceria produced a substantial amount of defects and O vacancies that led to high catalytic activity, selectivity and stability (i.e. resistance to coke formation) during ethanol steam reforming.less

  20. Mitigation of Sulfur Poisoning of Ni/Zirconia SOFC Anodes by Antimony and Tin

    SciTech Connect (OSTI)

    Marina, Olga A.; Coyle, Christopher A.; Engelhard, Mark H.; Pederson, Larry R.

    2011-02-28

    Surface Ni/Sb and Ni/Sb alloys were found to efficiently minimize the negative effects of sulfur on the performance of Ni/zirconia anode-supported solid oxide fuel cells (SOFC). Prior to operating on fuel gas containing low concentrations of H2S, the nickel/zirconia anodes were briefly exposed to antimony or tin vapor, which only slightly affected the SOFC performance. During the subsequent exposures to 1 and 5 ppm H2S, increases in anodic polarization losses were minimal compared to those observed for the standard nickel/zirconia anodes. Post-test XPS analyses showed that Sb and Sn tended to segregate to the surface of Ni particles, and further confirmed a significant reduction of adsorbed sulfur on the Ni surface in Ni/Sn and Ni/Sb samples compared to the Ni. The effect may be the result of weaker sulfur adsorption on bimetallic surfaces, adsorption site competition between sulfur and Sb or Sn on Ni, or other factors. The use of dilute binary alloys of Ni-Sb or Ni-Sn in the place of Ni, or brief exposure to Sb or Sn vapor, may be effective means to counteract the effects of sulfur poisoning in SOFC anodes and Ni catalysts. Other advantages, including suppression of coking or tailoring the anode composition for the internal reforming, are also expected.

  1. Atomic and electronic structure of Ni-Nb metallic glasses

    SciTech Connect (OSTI)

    Yuan, C. C.; Yang, Y.-F. Xi, X. K.

    2013-12-07

    Solid state {sup 93}Nb nuclear magnetic resonance spectroscopy has been employed to investigate the atomic and electronic structures in Ni-Nb based metallic glass (MG) model system. {sup 93}Nb nuclear magnetic resonance (NMR) isotropic metallic shift of Ni{sub 60}Nb{sub 35}Sn{sub 5} has been found to be ∼100 ppm lower than that of Ni{sub 60}Nb{sub 35}Zr{sub 5} MG, which is correlated with their intrinsic fracture toughness. The evolution of {sup 93}Nb NMR isotropic metallic shifts upon alloying is clearly an electronic origin, as revealed by both local hyperfine fields analysis and first-principle computations. This preliminary result indicates that, in addition to geometrical considerations, atomic form factors should be taken into a description of atomic structures for better understanding the mechanical behaviors of MGs.

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

    SciTech Connect (OSTI)

    Bhavsar, Saurabh; Veser, Goetz

    2013-11-06

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

  3. Weldability of an Ni/sub 3/Al alloy

    SciTech Connect (OSTI)

    Santella, M.L.; David, S.A.; Horton, J.A.

    1986-01-01

    Since joining by conventional welding processes is an important means of fabricating structural components, weldability has become a key issue in the development of these new Ni/sub 3/Al alloys. Results of an initial evaluation of the weldability of Ni/sub 3/Al containing 0.1 at. % B and 0.5 at. % Hf are reported. Plates were prepared by conventional methods and used to make full penetration electron beam and gas tungsten arc welds. Initial results indicate that hafnium improves the weldability of Ni/sub 3/Al alloys although they are still susceptible to cracking. Examination of microstructures indicated that a distinct microsegregation pattern developed in the welds and affected the ordering behavior of fusion zones. Room temperature tensile testing suggested that welds can have strength and ductility values comparable to base materials, and that postweld heat treatment can improve tensile properties.

  4. Healing of graphene on single crystalline Ni(111) films

    SciTech Connect (OSTI)

    Zeller, Patrick; Wintterlin, Joost; Speck, Florian; Ostler, Markus; Weinl, Michael; Schreck, Matthias; Seyller, Thomas

    2014-11-10

    The annealing of graphene layers grown on 150?nm thick single crystal Ni(111) films was investigated in situ by low energy electron microscopy and photoemission electron microscopy. After growth, by means of chemical vapor deposition of ethylene, the graphene layers consist of several domains showing different orientations with respect to the underlying Ni surface and also of small bilayer areas. It is shown that, in a controlled process, the rotated domains can be transformed into lattice-aligned graphene, and the bilayer areas can be selectively dissolved, so that exclusively the aligned monolayer graphene is obtained. The ordering mechanism involves transport of C atoms across the surface and solution in the bulk.

  5. Coexistence of charge-density wave and ferromagnetism in Ni2MnGa...

    Office of Scientific and Technical Information (OSTI)

    Coexistence of charge-density wave and ferromagnetism in Ni2MnGa Citation Details In-Document Search Title: Coexistence of charge-density wave and ferromagnetism in Ni2MnGa ...

  6. Solid-solution CrCoCuFeNi high-entropy alloy thin films synthesized...

    Office of Scientific and Technical Information (OSTI)

    Solid-solution CrCoCuFeNi high-entropy alloy thin films synthesized by sputter deposition Title: Solid-solution CrCoCuFeNi high-entropy alloy thin films synthesized by sputter ...

  7. Local Metal and Deuterium Ordering in the Deuterated ZrTiNi C14...

    Office of Scientific and Technical Information (OSTI)

    Local Metal and Deuterium Ordering in the Deuterated ZrTiNi C14 Laves Phase Citation Details In-Document Search Title: Local Metal and Deuterium Ordering in the Deuterated ZrTiNi ...

  8. Latent instabilities in metallic LaNiO₃ films by strain control...

    Office of Scientific and Technical Information (OSTI)

    LaNiO films by strain control of Fermi-surface topology Prev Next Title: Latent instabilities in metallic LaNiO films by strain control of Fermi-surface topology ...

  9. Latent instabilities in metallic LaNiO₃ films by strain control...

    Office of Scientific and Technical Information (OSTI)

    Latent instabilities in metallic LaNiO films by strain control of Fermi-surface topology Prev Next Title: Latent instabilities in metallic LaNiO films by strain control ...

  10. Deformation behavior of Nb nanowires in TiNiCu shape memory alloy...

    Office of Scientific and Technical Information (OSTI)

    in TiNiCu shape memory alloy matrix This content will become publicly available on August 18, 2016 Title: Deformation behavior of Nb nanowires in TiNiCu shape memory alloy matrix ...

  11. Fusion reactions of Ni 58 , 64 + Sn 124 (Journal Article) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    Fusion reactions of Ni 58 , 64 + Sn 124 Citation Details In-Document Search Title: Fusion reactions of Ni 58 , 64 + Sn 124 Authors: Jiang, C. L. ; Stefanini, A. M. ; Esbensen, H. ; ...

  12. Local structure study of Fe dopants in Ni-deficit Ni3Al alloys

    SciTech Connect (OSTI)

    V. N. Ivanovski; Umicevic, A.; Belosevic-Cavor, J.; Lei, Hechang; Li, Lijun; Cekic, B.; Koteski, V.; Petrovic, C.

    2015-08-24

    We found that the local electronic and magnetic structure, hyperfine interactions, and phase composition of polycrystalline Ni–deficient Ni 3-x FexAl (x = 0.18 and 0.36) were investigated by means of 57 Fe Mössbauer spectroscopy. The samples were characterized by X–ray diffraction and magnetization measurements. The ab initio calculations performed with the projector augmented wave method and the calculations of the energies of iron point defects were done to elucidate the electronic structure and site preference of Fe doped Ni 3 Al. Moreover, the value of calculated electric field gradient tensor Vzz=1.6 1021Vm-2 matches well with the results of Mössbauer spectroscopy and indicates that the Fe atoms occupy Ni sites.

  13. Superior performance of Ni-W-Ce mixed-metal oxide catalysts for ethanol steam reforming: Synergistic effects of W- and Ni-dopants

    SciTech Connect (OSTI)

    Rodriguez, Jose A.; Liu, Zongyuan; Xu, Wenqian; Yao, Siyu; Johnson-Peck, Aaron C.; Zhao, Fuzhen; Michorczyk, Piotr; Kubacka, Anna; Stach, Eric A.; Fernandez-Garica, Marcos; Senanayake, Sanjaya D.

    2014-11-26

    The ethanol steam reforming (ESR) reaction was studied over a series of Ni-W-Ce oxide catalysts. The structures of the catalysts were characterized using in-situ techniques including X-ray diffraction, Pair Distribution Function, X-ray absorption fine structure and transmission electron microscopy; while possible surface intermediates for the ESR reaction were investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy. In these materials, all the W and part of the Ni were incorporated into the CeO? lattice, with the remaining Ni forming highly dispersed nano NiO (< 2 nm) outside the Ni-W-Ce oxide structure. The nano NiO was reduced to Ni under ESR conditions. The Ni-W-Ce systeme exhibited a much larger lattice strain than those seen for Ni-Ce and W-Ce. Synergistic effects between Ni and W inside ceria produced a substantial amount of defects and O vacancies that led to high catalytic activity, selectivity and stability (i.e. resistance to coke formation) during ethanol steam reforming.

  14. Damage accumulation in ion-irradiated Ni-based concentrated solid-solution alloys

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

    Ullah, Mohammad W.; Aidhy, Dilpuneet S.; Zhang, Yanwen; Weber, William J.

    2016-01-01

    We investigate Irradiation-induced damage accumulation in Ni0.8Fe0.2 and Ni0.8Cr0.2 alloys by using molecular dynamics simulations to assess possible enhanced radiation-resistance in these face-centered cubic (fcc), single-phase, concentrated solid-solution alloys, as compared with pure fcc Ni.

  15. High strain rate deformation of NiAl

    SciTech Connect (OSTI)

    Maloy, S.A.; Gray, G.T. III; Darolia, R.

    1994-07-01

    NiAl is a potential high temperature structural material. Applications for which NiAl is being considered (such as rotating components in jet engines) requires knowledge of mechanical properties over a wide range of strain rates. Single crystal NiAl (stoichiometric and Ni 49.75Al 0.25Fe) has been deformed in compression along [100] at strain rates of 0.001, 0.1/s and 2000/s and temperatures of 76,298 and 773K. <111> slip was observed after 76K testing at a strain rate of 0.001/s and 298K testing at a strain rate of 2000/s. Kinking was observed after deformation at 298K and a strain rate of 0.001/s and sometimes at 298 K and a strain rate of 0.1/s. Strain hardening rates of 8200 and 4000 MPa were observed after 773 and 298K testing respectively, at a strain rate of 2000/s. Results are discussed in reference to resulting dislocation substructure.

  16. High Temperature coatings based on {beta}-NiAI

    SciTech Connect (OSTI)

    Severs, Kevin

    2012-07-10

    High temperature alloys are reviewed, focusing on current superalloys and their coatings. The synthesis, characerization, and oxidation performance of a NiAl–TiB{sub 2} composite are explained. A novel coating process for Mo–Ni–Al alloys for improved oxidation performance is examined. The cyclic oxidation performance of coated and uncoated Mo–Ni–Al alloys is discussed.

  17. High Tc YBCO superconductor deposited on biaxially textured Ni substrate

    DOE Patents [OSTI]

    Budai, John D.; Christen, David K.; Goyal, Amit; He, Qing; Kroeger, Donald M.; Lee, Dominic F.; List, III, Frederick A.; Norton, David P.; Paranthaman, Mariappan; Sales, Brian C.; Specht, Eliot D.

    1999-01-01

    A superconducting article includes a biaxially-textured Ni substrate, and epitaxial buffer layers of Pd (optional), CeO.sub.2 and YSZ, and a top layer of in-plane aligned, c-axis oriented YBCO having a critical current density (J.sub.c) in the range of at least 100,000 A/cm.sup.2 at 77 K.

  18. Electrochemical oxygen reduction catalysed by Ni3(hexaiminotriphenylene)2

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

    Miner, Elise M.; Fukushima, Tomohiro; Sheberla, Dennis; Sun, Lei; Surendranath, Yogesh; Dinca, Mircea

    2016-03-08

    Control over the architectural and electronic properties of heterogeneous catalysts poses a major obstacle in the targeted design of active and stable non-platinum group metal electrocatalysts for the oxygen reduction reaction. Here we introduce Ni3(HITP)2 (HITP=2, 3, 6, 7, 10, 11-hexaiminotriphenylene) as an intrinsically conductive metal-organic framework which functions as a well-defined, tunable oxygen reduction electrocatalyst in alkaline solution. Ni3(HITP)2 exhibits oxygen reduction activity competitive with the most active non-platinum group metal electrocatalysts and stability during extended polarization. The square planar Ni-N4 sites are structurally reminiscent of the highly active and widely studied non-platinum group metal electrocatalysts containing M-N4 units.more » Ni3(HITP)2 and analogues thereof combine the high crystallinity of metal-organic frameworks, the physical durability and electrical conductivity of graphitic materials, and the diverse yet well-controlled synthetic accessibility of molecular species. As a result, such properties may enable the targeted synthesis and systematic optimization of oxygen reduction electrocatalysts as components of fuel cells and electrolysers for renewable energy applications.« less

  19. Magnetic properties of Ni substituted Y-type barium ferrite

    SciTech Connect (OSTI)

    Won, Mi Hee; Kim, Chul Sung

    2014-05-07

    Y-type barium hexaferrite is attractive material for various applications, such as high frequency antennas and RF devices, because of its interesting magnetic properties. Especially, Ni substituted Y- type hexaferrites have higher magnetic ordering temperature than other Y-type. We have investigated macroscopic and microscopic properties of Y-type barium hexaferrite. Ba{sub 2}Co{sub 2−x}Ni{sub x}Fe{sub 12}O{sub 22} (x = 0, 0.5, 1.0, 1.5, and 2.0) samples are prepared by solid-state reaction method and studied by X-ray diffraction (XRD), vibrating sample magnetometer, and Mössbauer spectroscopy, as well as a network analyzer for high frequency characteristics. The XRD pattern is analyzed by Rietveld refinement method and confirms the hexagonal structure with R-3m. The hysteresis curve shows ferrimagnetic behavior. Saturation magnetization (M{sub s}) decreases with Ni contents. Ni{sup 2+}, which preferentially occupies the octahedral site with up-spin sub-lattice, has smaller spin value S of 1 than Co{sup 2+} having S = 3/2. The zero-field-cooled (ZFC) measurement of Ba{sub 2}Co{sub 1.5}Ni{sub 0.5}Fe{sub 12}O{sub 22} shows that Curie and spin transition temperatures are found to be 718 K and 209 K, respectively. The Curie temperature T{sub C} is increased with Ni contents, while T{sub S} is decreased with Ni. The Mössbauer spectra were measured at various temperatures and fitted by using a least-squares method with six sextet of six Lorentzian lines for Fe sites, corresponding to the 3b{sub VI}, 6c{sub IV}*, 6c{sub VI}, 18h{sub VI}, 6c{sub IV}, and 3a{sub IV} sites at below T{sub C}. From Mössbauer measurements, we confirmed the spin state of Fe ion to be Fe{sup 3+} and obtained the isomer shift (δ), magnetic hyperfine field (H{sub hf}), and the occupancy ratio of Fe ions at six sub-lattices. The complex permeability and permittivity are measured between 100 MHz and 4 GHz, suggesting that Y-type barium hexaferrite is promising for antenna

  20. 90° magnetic coupling in a NiFe/FeMn/biased NiFe multilayer spin valve component investigated by polarized neutron reflectometry

    SciTech Connect (OSTI)

    Callori, S. J. Bertinshaw, J.; Cortie, D. L.; Cai, J. W. Zhu, T.; Le Brun, A. P.; Klose, F.

    2014-07-21

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

  1. First-principles investigations of Ni3Al(111) and NiAl(110) surfaces at metal dusting conditions

    SciTech Connect (OSTI)

    Saadi, Souheil

    2011-03-01

    We investigate the structure and surface composition of the {gamma}{prime}-Ni{sub 3}Al(111) and {beta}-NiAl(110) alloy surfaces at conditions relevant for metal dusting corrosion related to catalytic steam reforming of natural gas. In regular service as protective coatings, nickel-aluminum alloys are protected by an oxide scale, but in case of oxide scale spallation, the alloy surface may be directly exposed to the reactive gas environment and vulnerable to metal dusting. By means of density functional theory and thermochemical calculations for both the Ni{sub 3}Al and NiAl surfaces, the conditions under which CO and OH adsorption is to be expected and under which it is inhibited, are mapped out. Because CO and OH are regarded as precursors for nucleating graphite or oxide on the surfaces, phase diagrams for the surfaces provide a simple description of their stability. Specifically, this study shows how the CO and OH coverages depend on the steam to carbon ratio (S/C) in the gas and thereby provide a ranking of the carbon limits on the different surface phases.

  2. Engineering of high performance supercapacitor electrode based on Fe-Ni/Fe{sub 2}O{sub 3}-NiO core/shell hybrid nanostructures

    SciTech Connect (OSTI)

    Singh, Ashutosh K. E-mail: aksingh@bose.res.in; Mandal, Kalyan

    2015-03-14

    The present work reports on fabrication and supercapacitor applications of a core/shell Fe-Ni/Fe{sub 2}O{sub 3}-NiO hybrid nanostructures (HNs) electrode. The core/shell Fe-Ni/Fe{sub 2}O{sub 3}-NiO hybrid nanostructures have been fabricated through a two step method (nanowire fabrication and their controlled oxidation). The 1D hybrid nanostructure consists of highly porous shell layer (redox active materials NiO and Fe{sub 2}O{sub 3}) and the conductive core (FeNi nanowire). Thus, the highly porous shell layer allows facile electrolyte diffusion as well as faster redox reaction kinetics; whereas the conductive FeNi nanowire core provides the proficient express way for electrons to travel to the current collector, which helps in the superior electrochemical performance. The core/shell Fe-Ni/Fe{sub 2}O{sub 3}-NiO hybrid nanostructures electrode based supercapacitor shows very good electrochemical performances in terms of high specific capacitance nearly 1415?F g{sup ?1} at a current density of 2.5?A g{sup ?1}, excellent cycling stability and rate capability. The high quality electrochemical performance of core/shell hybrid nanostructures electrode shows its potential as an alternative electrode for forthcoming supercapacitor devices.

  3. NiO nanoparticles induce apoptosis through repressing SIRT1 in human bronchial epithelial cells

    SciTech Connect (OSTI)

    Duan, Wei-Xia; He, Min-Di; Mao, Lin; Qian, Feng-Hua; Li, Yu-Ming; Pi, Hui-Feng; Liu, Chuan; Chen, Chun-Hai; Lu, Yong-Hui; Cao, Zheng-Wang; Zhang, Lei; Yu, Zheng-Ping; Zhou, Zhou

    2015-07-15

    With application of nano-sized nickel-containing particles (Nano-Ni) expanding, the health concerns about their adverse effects on the pulmonary system are increasing. However, the mechanisms for the pulmonary toxicity of these materials remain unclear. In the present study, we focused on the impacts of NiO nanoparticles (NiONPs) on sirtuin1 (SIRT1), a NAD-dependent deacetylase, and investigated whether SIRT1 was involved in NiONPs-induced apoptosis. Although the NiONPs tended to agglomerate in fluid medium, they still entered into the human bronchial epithelial cells (BEAS-2B) and released Ni{sup 2+} inside the cells. NiONPs at doses of 5, 10, and 20 μg/cm{sup 2} inhibited the cell viability. NiONPs' produced cytotoxicity was demonstrated through an apoptotic process, indicated by increased numbers of Annexin V positive cells and caspase-3 activation. The expression of SIRT1 was markedly down-regulated by the NiONPs, accompanied by the hyperacetylation of p53 (tumor protein 53) and overexpression of Bax (Bcl-2-associated X protein). However, overexpression of SIRT1 through resveratrol treatment or transfection clearly attenuated the NiONPs-induced apoptosis and activation of p53 and Bax. Our results suggest that the repression of SIRT1 may underlie the NiONPs-induced apoptosis via p53 hyperacetylation and subsequent Bax activation. Because SIRT1 participates in multiple biologic processes by deacetylation of dozens of substrates, this knowledge of the impact of NiONPs on SIRT1 may lead to an improved understanding of the toxic mechanisms of Nano-Ni and provide a molecular target to antagonize Nano-Ni toxicity. - Highlights: • NiONPs were taken up by BEAS-2B cells and released Ni{sup 2+}. • NiONPs produced cytotoxicity was demonstrated through an apoptotic process. • NiONPs repressed SIRT1 expression and activated p53 and Bax. • Overexpression of SIRT1 attenuated NiONPs-induced apoptosis via deacetylation p53.

  4. Temperature-induced sign change of the magnetic interlayer coupling in Ni/Ni{sub 25}Mn{sub 75}/Ni trilayers on Cu{sub 3}Au(001)

    SciTech Connect (OSTI)

    Shokr, Y. A.; Zhang, B.; Sandig, O.; Kuch, W.; Erkovan, M.; Wu, C.-B.

    2015-05-07

    We investigated the magnetic interlayer coupling between two ferromagnetic (FM) Ni layers through an antiferromagnetic (AFM) Ni{sub 25}Mn{sub 75} layer and the influence of this coupling on the exchange bias phenomenon. The interlayer coupling energy of an epitaxial trilayer of 14 atomic monolayers (ML) Ni/45 ML Ni{sub 25}Mn{sub 75}/16 ML Ni on Cu{sub 3}Au(001) was extracted from minor-loop magnetization measurements using in-situ magneto-optical Kerr effect. The interlayer coupling changes from ferromagnetic to antiferromagnetic when the temperature is increased above 300?K. This sign change is interpreted as the result of the competition between an antiparallel Ruderman-Kittel-Kasuya-Yosida (RKKY)-type interlayer coupling, which dominates at high temperature, and a stronger direct exchange coupling across the AFM layer, which is present only below the Nel temperature of the AFM layer.

  5. Novel electrolyte chemistries for Mg-Ni rechargeable batteries.

    SciTech Connect (OSTI)

    Garcia-Diaz, Brenda; Kane, Marie; Au, Ming

    2010-10-01

    Commercial hybrid electric vehicles (HEV) and battery electric vehicles (BEV) serve as means to reduce the nation's dependence on oil. Current electric vehicles use relatively heavy nickel metal hydride (Ni-MH) rechargeable batteries. Li-ion rechargeable batteries have been developed extensively as the replacement; however, the high cost and safety concerns are still issues to be resolved before large-scale production. In this study, we propose a new highly conductive solid polymer electrolyte for Mg-Ni high electrochemical capacity batteries. The traditional corrosive alkaline aqueous electrolyte (KOH) is replaced with a dry polymer with conductivity on the order of 10{sup -2} S/cm, as measured by impedance spectroscopy. Several potential novel polymer and polymer composite candidates are presented with the best-performing electrolyte results for full cell testing and cycling.

  6. Precipitation in 18 wt% Ni maraging steel of grade 350

    SciTech Connect (OSTI)

    Tewari, R.; Mazumder, S.; Batra, I.S.; Dey, G.K.; Banerjee, S.

    2000-03-14

    The evolution of precipitates in maraging steel of grade 350 was studied using the complementary techniques of small angle X-ray scattering (SACS) and transmission electron microscopy (TEM). These investigations revealed that ageing the steel at 703 K involved a rhombohedral distortion of the supersaturated b.c.c. martensite accompanied by the appearance of diffuse {omega}-like structures. This was followed by the appearance of well-defined {omega} particles containing chemical order. At the ageing temperature of 783 K, Ni{sub 3}(Ti,Mo) precipitates were the first to appear with a growth exponent of 1/3. The values of the Pored exponent obtained from the SAXS profiles indicated that the {omega} particles, formed below 723 K, had diffuse interfaces up to an ageing time of 48 h. On the other hand, Ni{sub 3}(Ti,Mo) precipitates, formed above 723 K, developed sharp interfaces in just about an hour. Also, the steel exhibited scaling in phase separation both at 703 and 783 K, but only during the early stages. Through this study it was established that at temperatures of ageing less than 723 K, evolution of {omega} particles takes place through the collapse of the unstable b.c.c. lattice and, at temperatures above 723 K, precipitation of A{sub 3}B type of phases through the mechanism of clustering and ordering of atomic species. Sharp interfaces develop rather quickly when the mechanism of precipitation involves development and amplification of a concentration wave along as in the nucleation of Ni{sub 3}(Ti,Mo) at 783 K than when an interplay of both the displacement and concentration waves is required as in the evolution of {omega} at 703 K. These results indicate towards the possibility of existence of two separate time-temperature-transformation (TTT) curves, one for the evolution of {omega}-phase and another for nucleation and growth of Ni{sub 3}(Ti,Mo).

  7. Intermixing in Cu/Ni multilayers induced by cold rolling

    SciTech Connect (OSTI)

    Wang, Z.; Perepezko, J. H.; Larson, D.; Reinhard, D.

    2015-04-28

    Repeated cold rolling was performed on multilayers of Cu60/Ni40 and Cu40/Ni60 foil arrays to study the details of driven atomic scale interfacial mixing. With increasing deformation, there is a significant layer refinement down to the nm level that leads to the formation of a solid solution phase from the elemental end members. Intriguingly, the composition of the solid solution is revealed by an oscillation in the composition profile across the multilayers, which is different from the smoothly varying profile due to thermally activated diffusion. During the reaction, Cu mixed into Ni preferentially compared to Ni mixing into Cu, which is also in contrast to the thermal diffusion behavior. This is confirmed by observations from X-ray diffraction, electron energy loss spectrum and atom probe tomography. The diffusion coefficient induced by cold rolling is estimated as 1.7 × 10{sup −17} m{sup 2}/s, which cannot be attributed to any thermal effect. The effective temperature due to the deformation induced mixing is estimated as 1093 K and an intrinsic diffusivity d{sub b}, which quantifies the tendency towards equilibrium in the absence of thermal diffusion, is estimated as 6.38 × 10{sup −18} m{sup 2}/s. The fraction of the solid solution phase formed is illustrated by examining the layer thickness distribution and is described by using an error function representation. The evolution of mixing in the solid solution phase is described by a simplified sinusoid model, in which the amplitude decays with increased deformation level. The promoted diffusion coefficient could be related to the effective temperature concept, but the establishment of an oscillation in the composition profile is a characteristic behavior that develops due to deformation.

  8. Martensite transformation of epitaxial Ni-Ti films

    SciTech Connect (OSTI)

    Buschbeck, J.; Kozhanov, A.; Kawasaki, J. K.; James, R. D.; Palmstroem, C. J.

    2011-05-09

    The structure and phase transformations of thin Ni-Ti shape memory alloy films grown by molecular beam epitaxy are investigated for compositions from 43 to 56 at. % Ti. Despite the substrate constraint, temperature dependent x-ray diffraction and resistivity measurements reveal reversible, martensitic phase transformations. The results suggest that these occur by an in-plane shear which does not disturb the lattice coherence at interfaces.

  9. Intermetallic phase formation and breakdown of Mo diffusion barriers in Ni-Mo-Cu and Ni-Mo-Monel 400 diffusion triads

    SciTech Connect (OSTI)

    Shueh, Y.

    1988-01-01

    The purpose of this research was to study the kinetics of compound formation and the interdiffusion behavior of a sacrificial type diffusion barrier in a model system. Ni-Mo diffusion couples were annealed in an inert atmosphere at 950-1050{degree}C for 5-300 hours. Ni-Mo-Cu and Ni-Mo-Monel 400 diffusion triads with varied thicknesses of Mo layers sandwiched by Ni and C or Monel 400 disks were annealed under the same conditions. Parabolic growth of the intermetallic phase, {beta}, was observed at 1000{degree}C and 1050{degree}C in the semi-infinite Ni-Mo diffusion couple an din the Ni-Mo-Cu diffusion triad when a finite thickness of the Mo layer remained. The {beta} phase exhibited more or less planar morphology except in the case of some extremely rugged interfaces which were associated with grain boundaries adjacent to these interfaces. Dissociation and recession of the compound layer in Ni-Mo-Cu diffusion triads initiated when the Mo layer was nearly consumed. The product phases of the dissociation reaction are consistent with those predicted from the Ni-Mo-Cu ternary phase diagram. Numerical methods based on a finite difference technique, and an analytical solution based on diffusion controlled parabolic growth and quasi-steady-state approximation in the {beta} phase region were used to analyze the results.

  10. Auxiliary Ligand-Dependent Assembly of Several Ni/Ni-Cd Compounds with N2O2 Donor Tetradentate Symmetrical Schiff Base Ligand

    SciTech Connect (OSTI)

    Ge, Ying Ying; Li, Guo-Bi; Fang, Hua-Cai; Zhan, Xu Lin; Gu, Zhi-Gang; Chen, Jin Hao; Sun, Feng; Cai, Yue-Peng; Thallapally, Praveen K.

    2010-09-18

    Several low-dimensional Ni/Ni-Cd complexes containing N2O2 donor tetradentate symmetrical Schiff base ligand bis(acetylacetone)ethylene-diamine (sy-H2L2), namely, [Ni(sy-L2)]2?HLa?ClO4 (2), (HLa)2?(ClO4)?(NO3) (3), [Ni(sy-L2)X]2](4,4-bipy) (where La = 5,7-dimethyl-3,6-dihydro-2H-1,4-diazepine, X = ClO4 (4), X=NO3 (5), [Ni(sy-L2)Cd(SCN)2]n (6) and [Ni(sy-L2)?Cd(N3)2]n (7) have been synthesized from [Ni(sy-L2)]2?H2O (1). Complex 2, is three component discrete assembly generated from (HLa)+ moiety bridged with [Ni(sy-L2)] unit and ClO4- anion. A solution containing complex 2 and Cd(NO3)2 results in a mixture of 1 and 3. Further re-crystallization of 1 and 3 with various auxiliary ligands, provides coordination complexes 4 7 stabilized by weak hydrogen bonds in which 6 and 7 represent the first 1D heteronuclear complexes based on symmetric acacen-base Schiff base ligand.

  11. Ni(OH){sub 2} nanoflakes electrodeposited on Ni foam-supported vertically oriented graphene nanosheets for application in asymmetric supercapacitors

    SciTech Connect (OSTI)

    Wang, Xin; Liu, Jiyue; Wang, Yayu; Zhao, Cuimei; Zheng, Weitao

    2014-04-01

    Highlights: Ni(OH){sub 2}/vertically oriented graphene nanosheets (V-GNs) was prepared. Ni(OH){sub 2}/V-GNs had enhanced specific capacitance, cycling reversibility and stability. Performance of Ni(OH){sub 2}/GNs/NF-AC asymmetric supercapacitor was studied. - Abstract: Binderless Ni(OH){sub 2} nanoflakes grown on Ni foam (NF)-supported vertically oriented graphene nanosheets (V-GNs) has been fabricated as a positive electrode material for asymmetric supercapacitor (ASC), coupled with activated carbon (AC) as a counter electrode material. The introduction of V-GNs leads to dense growth of nanocrystalline ?-Ni(OH){sub 2} that is confirmed by X-ray diffraction, transmission electron microscopic and scanning electron microscopic analyses. The electrochemical performances of the Ni(OH){sub 2}/GNs/NF electrode are characterized by cyclic voltammetry and chargedischarge tests, which exhibit high specific capacitance of 2215 F g{sup ?1} at a scan current density of 2.3 A g{sup ?1}, enhanced cycling stability and high rate capability. The Ni(OH){sub 2}/GNs/NF-AC-based ASC can achieve a cell voltage of 1.4 V and a specific energy density of 11.11 Wh kg{sup ?1} at 0.5 mA cm{sup ?2} with a nearly 100% coulombic efficiency at room temperature.

  12. Hydride bridge in [NiFe]-hydrogenase observed by nuclear resonance vibrational spectroscopy

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

    Ogata, Hideaki; Krämer, Tobias; Wang, Hongxin; Schilter, David; Pelmenschikov, Vladimir; van Gastel, Maurice; Neese, Frank; Rauchfuss, Thomas B.; Gee, Leland B.; Scott, Aubrey D.; et al

    2015-08-10

    The metabolism of many anaerobes relies on [NiFe]-hydrogenases, whose characterization when bound to substrates has proven non-trivial. Presented here is direct evidence for a hydride bridge in the active site of the 57Fe-labelled fully reduced Ni-R form of Desulfovibrio vulgaris Miyazaki F [NiFe]-hydrogenase. A unique ‘wagging’ mode involving H- motion perpendicular to the Ni(μ-H)57Fe plane was studied using 57Fe-specific nuclear resonance vibrational spectroscopy and density functional theory (DFT) calculations. On Ni(μ-D)57Fe deuteride substitution, this wagging causes a characteristic perturbation of Fe–CO/CN bands. Spectra have been interpreted by comparison with Ni(μ-H/D)57Fe enzyme mimics [(dppe)Ni(μ-pdt)(μ-H/D)57Fe(CO)3]+ and DFT calculations, which collectively indicate amore » low-spin Ni(II)(μ-H)Fe(II) core for Ni-R, with H- binding Ni more tightly than Fe. Lastly, the present methodology is also relevant to characterizing Fe–H moieties in other important natural and synthetic catalysts.« less

  13. Facile approach to prepare hollow coreshell NiO microspherers for supercapacitor electrodes

    SciTech Connect (OSTI)

    Han, Dandan; Xu, Pengcheng; Jing, Xiaoyan; Wang, Jun; Song, Dalei; Liu, Jingyuan; Zhang, Milin

    2013-07-15

    A facile lamellar template method (see image) has been developed for the preparation of uniform hollow coreshell structure NiO (HCSNiO) with a nanoarchitectured wall structure. The prepared NiO was found to be highly crystalline in uniform microstructures with high specific surface area and pore volume. The results indicated that ethanol interacted with trisodium citrate played an important role for the formation of hollow coreshell spheres. On the basis of the analysis of the composition and the morphology, a possible formation mechanism was investigated. NiO microspheres with hollow coreshell showed excellent capacitive properties. The exceptional cyclic, structural and electrochemical stability with ?95% coulombic efficiency, and very low ESR value from impedance measurements promised good utility value of hollow coreshell NiO material in fabricating a wide range of high-performance electrochemical supercapacitors. - The hollow coreshell NiO was prepared with a facile lamellar template method. The prepared NiO show higher capacitance, lower ion diffusion resistance and better electroactive surface utilization for Faradaic reactions. - Highlights: Formation of hollow coreshell NiO via a novel and facile precipitation route. Exhibited uniform feature sizes and high surface area of hollow coreshell NiO. Synthesized NiO has high specific capacitance ( 448 F g{sup 1}) and very low ESR value. Increased 20% of long life cycles capability after 500 chargedischarge cycles.

  14. Low temperature spin dynamics in Cr{sub 7}Ni-Cu-Cr{sub 7}Ni coupled molecular rings

    SciTech Connect (OSTI)

    Bordonali, L.; Furukawa, Y.; Mariani, M.; Sabareesh, K. P. V.; Garlatti, E.; Borsa, F.

    2014-05-07

    Proton Nuclear Magnetic Resonance (NMR) relaxation measurements have been performed down to very low temperature (50 mK) to determine the effect of coupling two Cr{sub 7}Ni molecular rings via a Cu{sup 2+} ion. No difference in the spin dynamics was found from nuclear spin lattice relaxation down to 1.5 K. At lower temperature, the {sup 1}H-NMR line broadens dramatically indicating spin freezing. From the plot of the line width vs. magnetization, it is found that the freezing temperature is higher (260 mK) in the coupled ring with respect to the single Cr{sub 7}Ni ring (140 mK)

  15. Room temperature synthesis of Ni-based alloy nanoparticles by radiolysis.

    SciTech Connect (OSTI)

    Nenoff, Tina Maria; Berry, Donald T.; Lu, Ping; Leung, Kevin; Provencio, Paula Polyak; Stumpf, Roland Rudolph; Huang, Jian Yu; Zhang, Zhenyuan

    2009-09-01

    Room temperature radiolysis, density functional theory, and various nanoscale characterization methods were used to synthesize and fully describe Ni-based alloy nanoparticles (NPs) that were synthesized at room temperature. These complementary methods provide a strong basis in understanding and describing metastable phase regimes of alloy NPs whose reaction formation is determined by kinetic rather than thermodynamic reaction processes. Four series of NPs, (Ag-Ni, Pd-Ni, Co-Ni, and W-Ni) were analyzed and characterized by a variety of methods, including UV-vis, TEM/HRTEM, HAADF-STEM and EFTEM mapping. In the first focus of research, AgNi and PdNi were studied. Different ratios of Ag{sub x}- Ni{sub 1-x} alloy NPs and Pd{sub 0.5}- Ni{sub 0.5} alloy NP were prepared using a high dose rate from gamma irradiation. Images from high-angle annular dark-field (HAADF) show that the Ag-Ni NPs are not core-shell structure but are homogeneous alloys in composition. Energy filtered transmission electron microscopy (EFTEM) maps show the homogeneity of the metals in each alloy NP. Of particular interest are the normally immiscible Ag-Ni NPs. All evidence confirmed that homogeneous Ag-Ni and Pd-Ni alloy NPs presented here were successfully synthesized by high dose rate radiolytic methodology. A mechanism is provided to explain the homogeneous formation of the alloy NPs. Furthermore, studies of Pd-Ni NPs by in situ TEM (with heated stage) shows the ability to sinter these NPs at temperatures below 800 C. In the second set of work, CoNi and WNi superalloy NPs were attempted at 50/50 concentration ratios using high dose rates from gamma irradiation. Preliminary results on synthesis and characterization have been completed and are presented. As with the earlier alloy NPs, no evidence of core-shell NP formation occurs. Microscopy results seem to indicate alloying occurred with the CoNi alloys. However, there appears to be incomplete reduction of the Na{sub 2}WO{sub 4} to form the W

  16. PT AND PT/NI "NEEDLE" ELETROCATALYSTS ON CARBON NANOTUBES WITH HIGH ACTIVITY FOR THE ORR

    SciTech Connect (OSTI)

    Colon-Mercado, H.

    2011-11-10

    Platinum and platinum/nickel alloy electrocatalysts supported on graphitized (gCNT) or nitrogen doped carbon nanotubes (nCNT) are prepared and characterized. Pt deposition onto carbon nanotubes results in Pt 'needle' formations that are 3.5 nm in diameter and {approx}100 nm in length. Subsequent Ni deposition and heat treatment results in PtNi 'needles' with an increased diameter. All Pt and Pt/Ni materials were tested as electrocatalysts for the oxygen reduction reaction (ORR). The Pt and Pt/Ni catalysts showed excellent performance for the ORR, with the heat treated PtNi/gCNT (1.06 mA/cm{sup 2}) and PtNi/nCNT (0.664 mA/cm{sup 2}) showing the highest activity.

  17. Effect of Cu addition on the martensitic transformation of powder metallurgy processed Ti–Ni alloys

    SciTech Connect (OSTI)

    Kim, Yeon-wook; Choi, Eunsoo

    2014-10-15

    Highlights: • M{sub s} of Ti{sub 50}Ni{sub 50} powders is 22 °C, while M{sub s} of SPS-sintered porous bulk increases up to 50 °C. • M{sub s} of Ti{sub 50}Ni{sub 40}Cu{sub 20} porous bulk is only 2 °C higher than that of the powders. • Recovered stain of porous TiNi and TiNiCu alloy is more than 1.5%. - Abstract: Ti{sub 50}Ni{sub 50} and Ti{sub 50}Ni{sub 30}Cu{sub 20} powders were prepared by gas atomization and their transformation behaviors were examined by means of differential scanning calorimetry and X-ray diffraction. One-step B2–B19’ transformation occurred in Ti{sub 50}Ni{sub 50} powders, while Ti{sub 50}Ni{sub 30}Cu{sub 20} powders showed B2–B19 transformation behavior. Porous bulks with 24% porosity were fabricated by spark plasma sintering. The martensitic transformation start temperature (50 °C) of Ti{sub 50}Ni{sub 50} porous bulk is much higher than that (22 °C) of the as-solidified powders. However, the martensitic transformation start temperature (35 °C) of Ti{sub 50}Ni{sub 30}Cu{sub 20} porous bulk is almost the same as that (33 °C) of the powders. When the specimens were compressed to the strain of 8% and then unloaded, the residual strains of Ti{sub 50}Ni{sub 50} and Ti{sub 50}Ni{sub 30}Cu{sub 20} alloy bulks were 3.95 and 3.7%, respectively. However, these residual strains were recovered up to 1.7% after heating by the shape memory phenomenon.

  18. Structural and Mssbauer spectroscopic study of Fe-Ni alloy nanoparticles

    SciTech Connect (OSTI)

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

    2014-04-24

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

  19. Prompt Proton Decay and Deformed Bands in 56Ni

    SciTech Connect (OSTI)

    Johansson, E. K.; Rudolph, D.; Andersson, L. L.; Torres, D. A.; Ragnarsson, I.; Andreoiu, C.; Baktash, Cyrus; Carpenter, M. P.; Charity, R. J.; Chiara, C. J.; Ekman, J.; Fahlander, C.; Hoel, C.; Pechenaya, O. L.; Reviol, W.; du Rietz, R.; Sarantites, D. G.; Seweryniak, D.; Sobotka, L. G.; Yu, Chang-Hong; Zhu, S.

    2008-06-01

    High-spin states in the doubly magic N=Z nucleus {sup 56}Ni have been investigated with three fusion-evaporation reaction experiments. New {gamma}-ray transitions are added, and a confirmation of a previously suggested prompt proton decay from a rotational band in {sup 56}Ni into the ground state of {sup 55}Co is presented. The rotational bands in {sup 56}Ni are discussed within the framework of cranked Nilsson-Strutinsky calculations.

  20. Simple route for the synthesis of supercapacitive Co-Ni mixed hydroxide thin films

    SciTech Connect (OSTI)

    Dubal, D.P.; Department of Materials Science and Engineering, Gwangju Institute of Science and Technology, 261 Cheomdan-gwagiro, Buk-gu, Gwangju 500-712 ; Jagadale, A.D.; Patil, S.V.; Lokhande, C.D.

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer Novel method for deposition of Co-Ni mixed hydroxide. Black-Right-Pointing-Pointer Nanoparticle network of Co-Ni hydroxide. Black-Right-Pointing-Pointer High specific capacitance of 672 F g{sup -1}. Black-Right-Pointing-Pointer High discharge/charge rates. -- Abstract: Facile synthesis of Co-Ni mixed hydroxides films with interconnected nanoparticles networks through two step route is successfully established. These films have been characterized by X-ray diffraction (XRD), Fourier transform infrared technique (FTIR), scanning electron microscopy (SEM) and wettability test. Co-Ni film formation is confirmed from XRD and FTIR study. SEM shows that the surface of Co-Ni films is composed of interconnected nanoparticles. Contact angle measurement revealed the hydrophilic nature of films which is feasible for the supercapacitor. The electrochemical performance of the film is evaluated by cyclic voltammetry, and constant-current charge/discharge cycling techniques. Specific capacitance of the Co-Ni mixed hydroxide electrode achieved 672 F g{sup -1}. Impedance analysis shows that Co-Ni mixed hydroxide electrode provides less resistance for the intercalation and de-intercalation of ions. The Co-Ni mixed electrode exhibited good charge/discharge rate at different current densities. The results demonstrated that Co-Ni mixed hydroxide composite is very promising for the next generation high performance electrochemical supercapacitors.

  1. Ductile Ni.sub.3 Al alloys as bonding agents for ceramic materials

    DOE Patents [OSTI]

    Tiegs, Terry N.; McDonald, Robert R.

    1990-01-01

    An improved ceramic-metal composite comprising a mixture of a ceramic material with a ductile intermetallic alloy, preferably Ni.sub.3 Al.

  2. Ductile Ni[sub 3]Al alloys as bonding agents for ceramic materials in cutting tools

    DOE Patents [OSTI]

    Tiegs, T.N.; McDonald, R.R.

    1991-05-14

    An improved ceramic-metal composite comprising a mixture of a ceramic material with a ductile intermetallic alloy, preferably Ni[sub 3]Al is disclosed. 2 figures.

  3. Ductile Ni.sub.3 Al alloys as bonding agents for ceramic materials in cutting tools

    DOE Patents [OSTI]

    Tiegs, Terry N.; McDonald, Robert R.

    1991-01-01

    An improved ceramic-metal composite comprising a mixture of a ceramic material with a ductile intermetallic alloy, preferably Ni.sub.3 Al.

  4. Ductile Ni[sub 3]Al alloys as bonding agents for ceramic materials

    DOE Patents [OSTI]

    Tiegs, T.N.; McDonald, R.R.

    1990-04-24

    An improved ceramic-metal composite is described comprising a mixture of a ceramic material with a ductile intermetallic alloy, preferably Ni[sub 3]Al. 2 figs.

  5. Self-assembled Ni/TiO{sub 2} nanocomposite anodes synthesized...

    Office of Scientific and Technical Information (OSTI)

    Ni(core)TiOsub 2(shell) nanocomposite anodes were fabricated on three-dimensional, self-assembled nanotemplates of Tobacco mosaic virus using atomic layer deposition, exhibiting ...

  6. SF6432-NI Fixed Price Contracts with the Newly Independent States...

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

    ... SITES (a) Permission to enter U.S. Government sites shall ... SF 6432-NI Title: Standard Terms & Conditions for Fixed ... premises are subject to search. (e) Contractor will ...

  7. SF6432-NI Fixed Price Contracts with the Newly Independent States...

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

    ... SITES Permission to enter U.S. Government sites shall ... premises are subject to search. (e) Contractor will ... Control : SF 6432-NI Title: Standard Terms & Conditions for ...

  8. Interfacial engineering of solution-processed Ni nanochain-SiOx...

    Office of Scientific and Technical Information (OSTI)

    Title: Interfacial engineering of solution-processed Ni ... 03755, USA Department of Chemical and Materials ... Type: Publisher's Accepted Manuscript Journal Name: Journal ...

  9. NiSource Energy Technologies Inc.: System Integration of Distributed Power for Complete Building Systems

    SciTech Connect (OSTI)

    Not Available

    2003-10-01

    Summarizes NiSource Energy Technologies' work under contract to DOE's Distribution and Interconnection R&D. Includes studying distributed generation interconnection issues and CHP system performance.

  10. Blending Cr2O3 into a NiO-Ni electrocatalyst for sustained water splitting

    SciTech Connect (OSTI)

    Gong, Ming; Zhou, Wu; Kenney, Michael James; Kapusta, Rich; Cowley, Sam; Wu, Yingpeng; Lu, Bingan; Lin, Meng -Chang; Wang, Di -Yan; Yang, Jiang; Hwang, Bing -Joe; Dai, Hongjie

    2015-08-24

    The rising H2 economy demands active and durable electrocatalysts based on low-cost, earth-abundant materials for water electrolysis/photolysis. Here we report nanoscale Ni metal cores over-coated by a Cr2O3-blended NiO layer synthesized on metallic foam substrates. The Ni@NiO/Cr2O3 triphase material exhibits superior activity and stability similar to Pt for the hydrogen-evolution reaction in basic solutions. The chemically stable Cr2O3 is crucial for preventing oxidation of the Ni core, maintaining abundant NiO/Ni interfaces as catalytically active sites in the heterostructure and thus imparting high stability to the hydrogen-evolution catalyst. The highly active and stable electrocatalyst enables an alkaline electrolyzer operating at 20 mA cm2 at a voltage lower than 1.5 V, lasting longer than 3 weeks without decay. Thus, the non-precious metal catalysts afford a high efficiency of about 15 % for light-driven water splitting using GaAs solar cells.

  11. Hydrogen production via reforming of biogas over nanostructured Ni/Y catalyst: Effect of ultrasound irradiation and Ni-content on catalyst properties and performance

    SciTech Connect (OSTI)

    Sharifi, Mahdi; Haghighi, Mohammad; Abdollahifar, Mozaffar

    2014-12-15

    Highlights: • Synthesis of nanostructured Ni/Y catalyst by sonochemical and impregnation methods. • Enhancement of size distribution and active phase dispersion by employing sonochemical method. • Evaluation of biogas reforming over Ni/Y catalyst with different Ni-loadings. • Preparation of highly active and stable catalyst with low Ni content for biogas reforming. • Getting H{sub 2}/CO very close to equilibrium ratio by employing sonochemical method. - Abstract: The effect of ultrasound irradiation and various Ni-loadings on dispersion of active phase over zeolite Y were evaluated in biogas reforming for hydrogen production. X-ray diffraction, field emission scanning electron microscopy, energy dispersive X-ray, Brunauer–Emmett–Teller, Fourier transform infrared analysis and TEM analysis were employed to observe the characteristics of nanostructured catalysts. The characterizations implied that utilization of ultrasound irradiation enhanced catalyst physicochemical properties including high dispersion of Ni on support, smallest particles size and high catalyst surface area. The reforming reactions were carried out at GHSV = 24 l/g.h, P = 1 atm, CH{sub 4}/CO{sub 2} = 1 and temperature range of 550–850 °C. Activity test displayed that ultrasound irradiated Ni(5 wt.%)/Y had the best performance and the activity remained stable during 600 min. Furthermore, the proposed reaction mechanism showed that there are three major reaction channels in biogas reforming.

  12. Investigation of defect clusters in ion-irradiated Ni and NiCo using diffuse X-ray scattering and electron microscopy

    SciTech Connect (OSTI)

    Olsen, Raina J.; Jin, Ke; Lu, Chenyang; Beland, Laurent K.; Wang, Lumin M.; Bei, Hongbin; Specht, Eliot D.; Larson, Bennett C.

    2016-01-01

    The nature of defect clusters in Ni and Ni$_{50}$Co$_{50}$ (NiCo) irradiated at room temperature with 2–16 MeV Ni ions is studied using asymptotic diffuse X-ray scattering and transmission electron microscopy (TEM). Analysis of the scattering data provides separate size distributions for vacancy and interstitial type defect clusters, showing that both types of defect clusters have a smaller size and higher density in NiCo than in Ni. Diffuse scattering results show good quantitative agreement with TEM results for cluster sizes greater than 4 nm diameter, but find that the majority of vacancy clusters are under 2 nm in NiCo, which, if not detected, would lead to the conclusion that defect density was actually lower in the alloy. Interstitial dislocation loops and stacking fault tetrahedra are identified by TEM. Lastly comparison of diffuse scattering lineshapes to those calculated for dislocation loops and SFTs indicates that most of the vacancy clusters are SFTs.

  13. Improved synthesis and crystal structure of the flexible pillared layer porous coordination polymer: Ni(1,2-bis(4-pyridyl)ethylene)[Ni(CN)4

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

    Wong-Ng, W.; Culp, J. T.; Chen, Y. S.; Zavalij, P.; Espinal, L.; Siderius, D. W.; Allen, A. J.; Scheins, S.; Matranga, C.

    2013-01-01

    This paper reports our synthesis of flexible coordination polymer, Ni(L)[Ni(CN)4], (L = 1,2-bis(4-pyridyl)ethylene (nicknamed bpene)), and its structural characterization using synchrotron single crystal X-ray diffraction. The structure of the purplish crystals has been determined to be monoclinic, space group P21/m, a = 13.5941(12) Å, b = 14.3621(12) Å, c = 14.2561(12) Å, β = 96.141(2)°, V = 2767.4(4) Å3, Z = 4, Dc = 1.46 g cm-1. Ni(bpene)[Ni(CN)4] assumes a pillared layer structure with layers defined by Ni[Ni(CN)4]n nets and bpene ligands acting as pillars. With the present crystallization technique which involves the use of concentrated ammonium hydroxide solution andmore » dimethyl sulfoxide (DMSO), disordered free bpene ligands and solvents of crystallization (DMSO and water molecules) occupy the pores, resulting in a formula of Ni(bpene)[Ni(CN)4](1/2)bpene∙DMSO2H2O, or Ni2N7C24H25SO3. Without the inclusion of free bpene ligands and solvent molecules, the free volume is approximately 61% of the total volume; this free volume fraction is reduced to 50% with the free ligands present. Pores without the free ligands were found to have a local diameter of 5.7 Å and a main aperture of 3.5 Å. Based on the successful crystal synthesis, we also devised a new bulk synthetic technique which yielded a polycrystalline material with a significantly improved CO2 uptake as compared to the originally reported powder material. The improved synthetic technique yielded a polycrystalline material with 40% higher CO2 uptake compared to the previously reported powder material. An estimated 14.4 molecules of CO2 per unit cell was obtained.« less

  14. Effect of the accumulation of excess Ni atoms in the crystal structure of the intermetallic semiconductor n-ZrNiSn

    SciTech Connect (OSTI)

    Romaka, V. A.; Rogl, P.; Romaka, V. V.; Stadnyk, Yu. V.; Hlil, E. K.; Krajovskii, V. Ya.; Horyn, A. M.

    2013-07-15

    The crystal structure, electron density distribution, and energy, kinetic, and magnetic properties of the n-ZrNiSn intermetallic semiconductor heavily doped with a Ni impurity are investigated. The effect of the accumulation of an excess number of Ni{sub 1+x} atoms in tetrahedral interstices of the crystal structure of the semiconductor is found and the donor nature of such structural defects that change the properties of the semiconductor is established. The results obtained are discussed within the Shklovskii-Efros model of a heavily doped and strongly compensated semiconductor.

  15. Cu-Ni-Fe anodes having improved microstructure

    DOE Patents [OSTI]

    Bergsma, S. Craig; Brown, Craig W.

    2004-04-20

    A method of producing aluminum in a low temperature electrolytic cell containing alumina dissolved in an electrolyte. The method comprises the steps of providing a molten electrolyte having alumina dissolved therein in an electrolytic cell containing the electrolyte. A non-consumable anode and cathode is disposed in the electrolyte, the anode comprised of Cu--Ni--Fe alloys having single metallurgical phase. Electric current is passed from the anode, through the electrolyte to the cathode thereby depositing aluminum on the cathode, and molten aluminum is collected from the cathode.

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

    DOE Patents [OSTI]

    Natesan, K.; Baxter, D.J.

    1983-07-26

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

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

    DOE Patents [OSTI]

    Natesan, Ken; Baxter, David J.

    1984-01-01

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

  18. Stable atomic structure of NiTi austenite

    SciTech Connect (OSTI)

    Zarkevich, Nikolai A; Johnson, Duane D

    2014-08-01

    Nitinol (NiTi), the most widely used shape-memory alloy, exhibits an austenite phase that has yet to be identified. The usually assumed austenitic structure is cubic B2, which has imaginary phonon modes, hence it is unstable. We suggest a stable austenitic structure that on average has B2 symmetry (observed by x-ray and neutron diffraction), but it exhibits finite atomic displacements from the ideal B2 sites. The proposed structure has a phonon spectrum that agrees with that from neutron scattering, has diffraction spectra in agreement with x-ray diffraction, and has an energy relative to the ground state that agrees with calorimetry data.

  19. Mo{sub 2}NiB{sub 2}-type (Gd, Tb, Dy){sub 2}Ni{sub 2.35}Si{sub 0.65} and La{sub 2}Ni{sub 3}-type (Dy, Ho){sub 2}Ni{sub 2.5}Si{sub 0.5} compounds: Crystal structure and magnetic properties

    SciTech Connect (OSTI)

    Morozkin, A.V.; Isnard, O.; Nirmala, R.; Malik, S.K.

    2015-05-15

    The crystal structure of new Mo{sub 2}NiB{sub 2}-type (Gd, Tb, Dy){sub 2}Ni{sub 2.35}Si{sub 0.65} (Immm, No. 71, oI10) and La{sub 2}Ni{sub 3}-type (Dy, Ho){sub 2}Ni{sub 2.5}Si{sub 0.5} (Cmce No. 64, oC20) compounds has been established using powder X-ray diffraction studies. Magnetization measurements show that the Mo{sub 2}NiB{sub 2}-type Gd{sub 2}Ni{sub 2.35}Si{sub 0.65} undergoes a ferromagnetic transition at ~66 K, whereas isostructural Tb{sub 2}Ni{sub 2.35}Si{sub 0.65} shows an antiferromagnetic transition at ~52 K and a field-induced metamagnetic transition at low temperatures. Neutron diffraction study shows that, in zero applied field, Tb{sub 2}Ni{sub 2.35}Si{sub 0.65} exhibits c-axis antiferromagnetic order with propagation vector K=[1/2, 0, 1/2] below its magnetic ordering temperature and Tb magnetic moment reaches a value of 8.32(5) μ{sub B} at 2 K. The La{sub 2}Ni{sub 3}-type Dy{sub 2}Ni{sub 2.5}Si{sub 0.5} exhibits ferromagnetic like transition at ~42 K with coexisting antiferromagnetic interactions and field induced metamagnetic transition below ~17 K. The magnetocaloric effect of Gd{sub 2}Ni{sub 2.35}Si{sub 0.65}, Tb{sub 2}Ni{sub 2.35}Si{sub 0.65} and Dy{sub 2}Ni{sub 2.5}Si{sub 0.5} is calculated in terms of isothermal magnetic entropy change and it reaches a maximum value of −14.3 J/kg K, −5.3 J/kg K and −10.3 J/kg K for a field change of 50 kOe near 66 K, 52 K and 42 K, respectively. Low temperature magnetic ordering with enhanced anisotropic effects in Tb{sub 2}Ni{sub 2.35}Si{sub 0.65} and Dy{sub 2}Ni{sub 2.35}Si{sub 0.65} is accompanied by a positive magnetocaloric effect with isothermal magnetic entropy changes of +12.8 J/kg K and ~+9.9 J/kg K, respectively at 7 K for a field change of 50 kOe. - Graphical abstract: The (Gd, Tb, Dy){sub 2}Ni{sub 2.35}Si{sub 0.65} supplement the series of Mo{sub 2}NiB{sub 2}-type rare earth compounds, whereas the (Dy, Ho){sub 2}Ni{sub 2.5}Si{sub 0.5} supplement the series of La{sub 2}Ni{sub 3}-type rare

  20. Deformations and magnetic rotations in the {sup 60}Ni nucleus

    SciTech Connect (OSTI)

    Torres, D. A.; Cristancho, F.; Andersson, L.-L.; Johansson, E. K.; Rudolph, D.; Fahlander, C.; Ekman, J.; Rietz, R. du; Andreoiu, C.; Carpenter, M. P.; Seweryniak, D.; Zhu, S.; Charity, R. J.; Chiara, C. J.; Hoel, C.; Pechenaya, O. L.; Reviol, W.; Sarantites, D. G.; Sobotka, L. G.; Baktash, C.

    2008-11-15

    Data from three experiments using the heavy-ion fusion evaporation-reaction {sup 36}Ar+{sup 28}Si have been combined to study high-spin states in the residual nucleus {sup 60}Ni, which is populated via the evaporation of four protons from the compound nucleus {sup 64}Ge. The GAMMASPHERE array was used for all the experiments in conjunction with a 4{pi} charged-particle detector arrays (MICROBALL, LUWUSIA) and neutron detectors (NEUTRON SHELL) to allow for the detection of {gamma} rays in coincidence with the evaporated particles. An extended {sup 60}Ni level scheme is presented, comprising more than 270{gamma}-ray transitions and 110 excited states. Their spins and parities have been assigned via directional correlations of {gamma} rays emitted from oriented states. Spherical shell-model calculations in the fp-shell characterize some of the low-spin states, while the experimental results of the rotational bands are analyzed with configuration-dependent cranked Nilsson-Strutinsky calculations.

  1. Doubly-magic nature of {sup 56}Ni: Measurement of the ground state nuclear magnetic dipole moment of {sup 55}Ni

    SciTech Connect (OSTI)

    Berryman, J. S.; Crawford, H. L.; Mantica, P. F.; Stoker, J. B.; Minamisono, K.; Grinyer, G. F.; Rogers, W. F.; Brown, B. A.; Towner, I. S.

    2009-06-15

    The nuclear magnetic moment of the ground state of {sup 55}Ni (I{sup {pi}}=3/2{sup -}, T{sub 1/2}=204 ms) has been deduced to be |{mu}({sup 55}Ni)|=(0.976{+-}0.026) {mu}{sub N} using the {beta}-ray detecting nuclear magnetic resonance technique. Results of a shell model calculation in the full fp shell model space with the GXPF1 interaction reproduce the experimental value. Together with the known magnetic moment of the mirror partner {sup 55}Co, the isoscalar spin expectation value was extracted as <{sigma}{sigma}{sub z}>=0.91{+-}0.07. The <{sigma}{sigma}{sub z}> shows a trend similar to that established in the sd shell. The present theoretical interpretations of both {mu}({sup 55}Ni) and <{sigma}{sigma}{sub z}> for the T=1/2, A=55 mirror partners support the softness of the {sup 56}Ni core.

  2. Effect of Co/Ni ratios in cobalt nickel mixed oxide catalysts on methane combustion

    SciTech Connect (OSTI)

    Lim, Tae Hwan; Cho, Sung June; Yang, Hee Sung; Engelhard, Mark H.; Kim, Do Heui

    2015-07-31

    A series of cobalt nickel mixed oxide catalysts with the varying ratios of Co to Ni, prepared by co-precipitation method, were applied to methane combustion. Among the various ratios, cobalt nickel mixed oxides having the ratios of Co to Ni of (50:50) and (67:33) demonstrate the highest activity for methane combustion. Structural analysis obtained from X-ray diffraction (XRD) and extended X-ray absorption fine structure (EXAFS) evidently demonstrates that CoNi (50:50) and (67:33) samples consist of NiCo2O4and NiO phase and, more importantly, NiCo2O4spinel structure is largely distorted, which is attributed to the insertion of Ni2+ions into octahedral sites in Co3O4spinel structure. Such structural dis-order results in the enhanced portion of surface oxygen species, thus leading to the improved reducibility of the catalysts in the low temperature region as evidenced by temperature programmed reduction by hydrogen (H2TPR) and X-ray photoelectron spectroscopy (XPS) O 1s results. They prove that structural disorder in cobalt nickel mixed oxides enhances the catalytic performance for methane combustion. Thus, it is concluded that a strong relationship between structural property and activity in cobalt nickel mixed oxide for methane combustion exists and, more importantly, distorted NiCo2O4spinel structure is found to be an active site for methane combustion.

  3. Structure of the NiFe2O4(001) surface in contact with gaseous...

    Office of Scientific and Technical Information (OSTI)

    Structure of the NiFe2O4(001) surface in contact with gaseous O2 and water vapor Citation ... Title: Structure of the NiFe2O4(001) surface in contact with gaseous O2 and water vapor ...

  4. Crystallization study of amorphous sputtered NiTi bi-layer thin film

    SciTech Connect (OSTI)

    Mohri, Maryam; Nili-Ahmadabadi, Mahmoud; Chakravadhanula, Venkata Sai Kiran

    2015-05-15

    The crystallization of Ni-rich/NiTiCu bi-layer thin film deposited by magnetron sputtering from two separate alloy targets was investigated. To achieve the shape memory effect, the NiTi thin films deposited at room temperature with amorphous structure were annealed at 773 K for 15, 30, and 60 min for crystallization. Characterization of the films was carried out by differential scanning calorimetry to indicate the crystallization temperature, grazing incidence X-ray diffraction to identify the phase structures, atomic force microscopy to evaluate surface morphology, scanning transmission electron microscopy to study the cross section of the thin films. The results show that the structure of the annealed thin films strongly depends on the temperature and time of the annealing. Crystalline grains nucleated first at the surface and then grew inward to form columnar grains. Furthermore, the crystallization behavior was markedly affected by composition variations. - Highlights: • A developed bi-layer Ni45TiCu5/Ni50.8Ti was deposited on Si substrate and crystallized. • During crystallization, The Ni{sub 45}TiCu{sub 5} layer is thermally less stable than the Ni-rich layer. • The activation energy is 302 and 464 kJ/mol for Cu-rich and Ni-rich layer in bi-layer, respectively.

  5. Method For Making Electronic Circuits Having Nial And Ni3al Substrates

    DOE Patents [OSTI]

    Deevi, Seetharama C.; Sikka, Vinod K.

    2001-01-30

    A method for making electronic circuit component having improved mechanical properties and thermal conductivity comprises steps of providing NiAl and/or Ni.sub.3 Al, and forming an alumina layer thereupon prior to applying the conductive elements. Additional layers of copper-aluminum alloy or copper further improve mechanical strength and thermal conductivity.

  6. Features of primary damage by high energy displacement cascades in concentrated Ni-based alloys

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

    Béland, Laurent Karim; Lu, Chenyang; Osetskiy, Yuri N.; Samolyuk, German D.; Caro, Alfredo; Wang, Lumin; Stoller, Roger E.

    2016-02-25

    Alloying of Ni with Fe or Co reduces primary damage production under ion irradiation. Similar results have been obtained from classical molecular dynamics simulations of 1, 10, 20, and 40 keV collision cascades in Ni, NiFe, and NiCo. In all cases, a mix of imperfect stacking fault tetrahedra, faulted loops with a 1/3 {111} Burgers vector, and glissile interstitial loops with a 1/2 {110} Burgers vector were formed, along with small sessile point defect complexes and clusters. Primary damage reduction occurs by three mechanisms. First, Ni-Co, Ni-Fe, Co-Co, and Fe-Fe short-distance repulsive interactions are stiffer than Ni-Ni interactions, which leadmore » to a decrease in damage formation during the transition from the supersonic ballistic regime to the sonic regime. This largely controls final defect production. Second, alloying decreases thermal conductivity, leading to a longer thermal spike lifetime. The associated annealing reduces final damage production. These two mechanisms are especially important at cascades energies less than 40 keV. Third, at the higher energies, the production of large defect clusters by subcascades is inhibited in the alloys. A number of challenges and limitations pertaining to predictive atomistic modeling of alloys under high-energy particle irradiation are discussed.« less

  7. Nanoscale compositional analysis of NiTi shape memory alloy films deposited by DC magnetron sputtering

    SciTech Connect (OSTI)

    Sharma, S. K.; Mohan, S.; Bysakh, S.; Kumar, A.; Kamat, S. V.

    2013-11-15

    The formation of surface oxide layer as well as compositional changes along the thickness for NiTi shape memory alloy thin films deposited by direct current magnetron sputtering at substrate temperature of 300 °C in the as-deposited condition as well as in the postannealed (at 600 °C) condition have been thoroughly studied by using secondary ion mass spectroscopy, x-ray photoelectron spectroscopy, and scanning transmission electron microscopy-energy dispersive x-ray spectroscopy techniques. Formation of titanium oxide (predominantly titanium dioxide) layer was observed in both as-deposited and postannealed NiTi films, although the oxide layer was much thinner (8 nm) in as-deposited condition. The depletion of Ti and enrichment of Ni below the oxide layer in postannealed films also resulted in the formation of a graded microstructure consisting of titanium oxide, Ni{sub 3}Ti, and B2 NiTi. A uniform composition of B2 NiTi was obtained in the postannealed film only below a depth of 200–250 nm from the surface. Postannealed film also exhibited formation of a ternary silicide (Ni{sub x}Ti{sub y}Si) at the film–substrate interface, whereas no silicide was seen in the as-deposited film. The formation of silicide also caused a depletion of Ni in the film in a region ∼250–300 nm just above the film substrate interface.

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

    SciTech Connect (OSTI)

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

    2014-11-14

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

  9. Fundamental studies of high-temperature corrosion reactions. Sixth annual progress report. [Cu-6% Ni

    SciTech Connect (OSTI)

    Rapp, R.A.

    1981-02-01

    Research was conducted on the sulfidation of pure Mo by sulfur gases at 700 to 950/sup 0/C and on the in-situ oxidation of metals and alloys in the hot-stage SEM. Results on the in-situ oxidation of Cu, Ni, Fe, and Cu-6% Ni up to 930/sup 0/C are reported in detail. 21 figures.

  10. Flower-like NiO structures: Controlled hydrothermal synthesis and electrochemical characteristic

    SciTech Connect (OSTI)

    Chai, Hui; Chen, Xuan; Key Laboratory of Advanced Functional Materials, Institute of Applied Chemistry, Xinjiang University, Urumqi 830046, Xinjiang ; Jia, Dianzeng; Key Laboratory of Advanced Functional Materials, Institute of Applied Chemistry, Xinjiang University, Urumqi 830046, Xinjiang ; Bao, Shujuan; Key Laboratory of Advanced Functional Materials, Institute of Applied Chemistry, Xinjiang University, Urumqi 830046, Xinjiang ; Zhou, Wanyong

    2012-12-15

    Graphical abstract: Flower-like porous NiO was obtained via thermal decomposition of the precursor prepared by a hydrothermal process using hexamethylenetetramine and polyethylene glycol as hydrolysis-controlling agent and surfactant, respectively. The morphology and microstructure of as-synthesized NiO were characterized by X-ray diffraction (XRD), BrunauerEmmettTeller (BET), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results of electrochemical measurements demonstrated that the flower-like porous NiO has high capacity (340 F g{sup ?1}) with excellent cycling performance as electrode materials of electrochemical capacitors (ECs), which may be attributed to the unique microstrcture of NiO. Data analyses indicated that NiO with novel porous structure attractive for practical and large-scale applications in electrochemical capacitors. Display Omitted Highlights: ? Synthesis and characterization of NiO with novel porous structure is presented in this work. ? The electrochemical performance of product was examined. ? NiO with excellent performance as electrode materials may be due to the unique microstrcture. ? NiO with novel porous structure attractive for practical with high capacity (340 F g{sup ?1}). -- Abstract: Flower-like porous NiO was obtained by thermal decomposition of the precursor prepared by a hydrothermal process with hexamethylenetetramine and polyethylene glycol as hydrolysis-controlling agent and surfactant, respectively. The morphology and microstructure of as-synthesized NiO were characterized by X-ray diffraction (XRD), BrunauerEmmettTeller (BET), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The resulting structures of NiO exhibited porous like petal building blocks. The electrochemical measurements results demonstrated that flower-like porous NiO has high capacity (340 F g{sup ?1}) with excellent cycling performance as electrode materials for electrochemical capacitors

  11. Direct synthesis of porous NiO nanowall arrays on conductive substrates for supercapacitor application

    SciTech Connect (OSTI)

    Zhu, Jianhui; Jiang, Jian; Liu, Jingping; Ding, Ruimin; Ding, Hao; Feng, Yamin; Wei, Guangming; Huang, Xintang

    2011-03-15

    Porous NiO nanowall arrays (NWAs) grown on flexible Fe-Co-Ni alloy have been successfully synthesized by using nullaginite (Ni{sub 2}(OH){sub 2}CO{sub 3}) as precursor and investigated as supercapacitor electrodes. In details, we adopted a simple hydrothermal method to realize Ni{sub 2}(OH){sub 2}CO{sub 3} NWAs and examined their robust mechanical adhesion to substrate via a long-time ultrasonication test. Porous NiO NWAs were then obtained by a post-calcination towards precursors at 500 {sup o}C in nitrogen atmosphere. Electrochemical properties of as-synthesized NiO NWAs were evaluated by cyclic voltammetry and galvanostatic charge/discharge; porous NiO NWAs electrode delivered a specific capacitance of 270 F/g (0.67 A/g); even at high current densities, the electrode could still deliver a high capacitance up to 236 F/g (13.35 A/g). Meanwhile, it exhibited excellent cycle lifetime with {approx}93% specific capacitance kept after 4000 cycles. These results suggest that as-made porous NiO NWAs electrode is a promising candidate for future thin-film supercapacitors and other microelectronic systems. -- Graphical abstract: Porous NiO nanowall arrays (NWAs) grown on alloy substrate have been made using nullaginite as precursor and studied as supercapacitor electrodes. Porous nanowalls interconnected with each other resulting in the formation of extended-network architectures and exhibited excellent capacitor properties. NiO NWAs electrode delivered a capacitance of 270 F/g (0.67 A/g); even at high current density, the electrode could still deliver a high capacitance up to 236 F/g (13.35 A/g). Besides, it exhibited excellent cycle lifetime with {approx}93% capacitance kept after 4000 cycles. These remarkable results made it possible for mass production of NiO NWAs and future thin-film microelectronic applications. Display Omitted Research highlights: {yields} Large-scale nullaginite (Ni{sub 2}(OH){sub 2}CO{sub 3}) nanowall arrays (NWAs) have been synthesized on

  12. Monodisperse core/shell Ni/FePt nanoparticles and their con-version to Ni/Pt to catalyze oxygen reduction

    SciTech Connect (OSTI)

    Zhang, Sen; Hao, Yizhou; Su, Dong; Doan-Nguyen, Vicky V. T.; Wu, Yaoting; Li, Jing; Sun, Shouheng; Murray, Christopher B.

    2014-10-28

    We report a size-controllable synthesis of monodisperse core/shell Ni/FePt nanoparticles (NPs) via a seed-mediated growth and their subsequent conversion to Ni/Pt NPs. Preventing surface oxidation of the Ni seeds is essential for the growth of uniform FePt shells. These Ni/FePt NPs have a thin (≈ 1 nm) FePt shell, and can be converted to Ni/Pt by acetic acid wash to yield active catalysts for oxygen reduction reaction (ORR). Tuning the core size allow for optimization of their electrocatalytic activity. The specific activity and mass activity of 4.2 nm/0.8 nm core/shell Ni/FePt reach 1.95 mA/cm² and 490 mA/mgPt at 0.9 V (vs. reversible hydrogen electrode, RHE), which are much higher than those of benchmark commercial Pt catalyst (0.34 mA/cm² and 92 mA/mgPt at 0.9 V). Our studies provide a robust approach to monodisperse core/shell NPs with non-precious metal core, making it possible to develop advanced NP catalysts with ultralow Pt content for ORR and many other heterogeneous reactions.

  13. Hybrid Composite Ni(OH)(2)@NiCo2O4 Grown on Carbon Fiber Paper for High-Performance Supercapacitors

    SciTech Connect (OSTI)

    Huang, L; Chen, DC; Ding, Y; Wang, ZL; Zeng, ZZ; Liu, ML

    2013-11-13

    We have successfully fabricated and tested the electrochemical performance of supercapacitor electrodes consisting of Ni(OH)(2) nanosheets coated on NiCo2O4 nanosheets grown on carbon fiber paper (CFP) current collectors. When the NiCo2O4 nanosheets are replaced by Co3O4 nanosheets, however, the energy and power density as well as the rate capability of the electrodes are significantly reduced, most likely due to the lower conductivity of Co3O4 than that of NiCo2O4. The 3D hybrid composite Ni(OH)(2)/ NiCo2O4/CFP electrodes demonstrate a high areal capacitance of 5.2 F/cm(2) at a cycling current density of 2 rnA/cm(2), with a capacitance retention of 79% as the cycling current density was increased from 2 to 50 mA/cm(2). The remarkable performance of these hybrid composite electrodes implies that supercapacitors based on them have potential for many practical applications.

  14. Correlating Extent of PtNi Bond Formation with Low-temperature Hydrogenation of Benzene and 1,3-butadiene over Supported Pt/Ni Bimetallic Catalysts

    SciTech Connect (OSTI)

    Lonergan, W.; Vlachos, D; Chen, J

    2010-01-01

    Low-temperature hydrogenation of benzene and 1,3-butadiene on supported Pt/Ni catalysts have been used as probe reactions to correlate hydrogenation activity with the extent of Pt-Ni bimetallic bond formation. Pt/Ni bimetallic and Pt and Ni monometallic catalysts were supported on {gamma}-Al{sub 2}O{sub 3} using incipient wetness impregnation. Two sets of bimetallic catalysts were synthesized: one set to study the effect of metal atomic ratio and the other to study the effect of impregnation sequence. Fourier transform infrared spectroscopy (FTIR) CO adsorption studies were performed to characterize the surface composition of the bimetallic nanoparticles, and transmission electron microscopy (TEM) was utilized to characterize the particle size distribution. Batch reactor studies with FTIR demonstrated that all bimetallic catalysts outperformed monometallic catalysts for both benzene and 1,3-butadiene hydrogenation. Within the two sets of bimetallic catalysts, it was found that catalysts with a smaller Pt:Ni ratio possessed higher hydrogenation activity and that catalysts synthesized using co-impregnation had greater activity than sequentially impregnated catalysts. Extended X-ray absorption fine structure (EXAFS) measurements were performed in order to verify the extent of Pt-Ni bimetallic bond formation, which was found to correlate with the hydrogenation activity.

  15. Investigation of defect clusters in ion-irradiated Ni and NiCo using diffuse X-ray scattering and electron microscopy

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

    Olsen, Raina J.; Jin, Ke; Lu, Chenyang; Beland, Laurent K.; Wang, Lumin M.; Bei, Hongbin; Specht, Eliot D.; Larson, Bennett C.

    2016-01-01

    The nature of defect clusters in Ni and Nimore » $$_{50}$$Co$$_{50}$$ (NiCo) irradiated at room temperature with 2–16 MeV Ni ions is studied using asymptotic diffuse X-ray scattering and transmission electron microscopy (TEM). Analysis of the scattering data provides separate size distributions for vacancy and interstitial type defect clusters, showing that both types of defect clusters have a smaller size and higher density in NiCo than in Ni. Diffuse scattering results show good quantitative agreement with TEM results for cluster sizes greater than 4 nm diameter, but find that the majority of vacancy clusters are under 2 nm in NiCo, which, if not detected, would lead to the conclusion that defect density was actually lower in the alloy. Interstitial dislocation loops and stacking fault tetrahedra are identified by TEM. Lastly comparison of diffuse scattering lineshapes to those calculated for dislocation loops and SFTs indicates that most of the vacancy clusters are SFTs.« less

  16. Growth of c-axis oriented YBaCuO films on oxidized textured Ni sheets and on (100) and (110) oriented NiO single crystals

    SciTech Connect (OSTI)

    Ginsbach, A.; Schneider, R.; Grueninger, H.W.; Grabe, G. )

    1991-03-01

    This paper reports on YBaCuO films grown on oxidized textured Ni sheets and on (100) and (110) oriented NiO single crystals by magnetron sputter deposition from a stoichiometric tubular target. The properties of the YBaCuO films are investigated as function of various preparation parameters (oxidation procedure of the sheets, substrate temperature T{sub s}, HTSC film thickness). At T{sub s} = 780{degrees} C and for film thickness larger than 200 nm, the films have T{sub c} values around 80K. The textures of the Ni sheets, NiO layers and YBaCuO films are determined using X-ray diffraction in Bragg-Brentano geometry and scanning electron microscopy. It is remarkable, that on textured oxidized Ni the YBaCuO films grow c-axis oriented. For comparison the properties of films on differently oriented NiO single crystals are investigated. It is found that the film properties are better on (100) than on (110) surfaces.

  17. Monodisperse core/shell Ni/FePt nanoparticles and their con-version to Ni/Pt to catalyze oxygen reduction

    SciTech Connect (OSTI)

    Zhang, Sen; Su, Dong; Doan-Nguyen, Vicky V. T.; Wu, Yaoting; Li, Jing; Sun, Shouheng; Murray, Christopher B.; Hao, Yizhou

    2014-11-12

    We report a size-controllable synthesis of monodisperse core/shell Ni/FePt nanoparticles (NPs) via a seed-mediated growth and their subsequent conversion to Ni/Pt NPs. Preventing surface oxidation of the Ni seeds is essential for the growth of uniform FePt shells. These Ni/FePt NPs have a thin (? 1 nm) FePt shell, and can be converted to Ni/Pt by acetic acid wash to yield active catalysts for oxygen reduction reaction (ORR). Tuning the core size allow for optimization of their electrocatalytic activity. The specific activity and mass activity of 4.2 nm/0.8 nm core/shell Ni/FePt reach 1.95 mA/cm and 490 mA/mgPt at 0.9 V (vs. reversible hydrogen electrode, RHE), which are much higher than those of benchmark commercial Pt catalyst (0.34 mA/cm and 92 mA/mgPt at 0.9 V). Our studies provide a robust approach to monodisperse core/shell NPs with non-precious metal core, making it possible to develop advanced NP catalysts with ultralow Pt content for ORR and many other heterogeneous reactions.

  18. Monodisperse core/shell Ni/FePt nanoparticles and their con-version to Ni/Pt to catalyze oxygen reduction

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

    Zhang, Sen; Hao, Yizhou; Su, Dong; Doan-Nguyen, Vicky V. T.; Wu, Yaoting; Li, Jing; Sun, Shouheng; Murray, Christopher B.

    2014-10-28

    We report a size-controllable synthesis of monodisperse core/shell Ni/FePt nanoparticles (NPs) via a seed-mediated growth and their subsequent conversion to Ni/Pt NPs. Preventing surface oxidation of the Ni seeds is essential for the growth of uniform FePt shells. These Ni/FePt NPs have a thin (≈ 1 nm) FePt shell, and can be converted to Ni/Pt by acetic acid wash to yield active catalysts for oxygen reduction reaction (ORR). Tuning the core size allow for optimization of their electrocatalytic activity. The specific activity and mass activity of 4.2 nm/0.8 nm core/shell Ni/FePt reach 1.95 mA/cm² and 490 mA/mgPt at 0.9 Vmore » (vs. reversible hydrogen electrode, RHE), which are much higher than those of benchmark commercial Pt catalyst (0.34 mA/cm² and 92 mA/mgPt at 0.9 V). Our studies provide a robust approach to monodisperse core/shell NPs with non-precious metal core, making it possible to develop advanced NP catalysts with ultralow Pt content for ORR and many other heterogeneous reactions.« less

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

    SciTech Connect (OSTI)

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

    2014-04-24

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

  20. Near-barrier fusion and barrier distribution of {sup 58}Ni+{sup 54}Fe

    SciTech Connect (OSTI)

    Stefanini, A. M.; Corradi, L.; Fioretto, E.; Silvestri, R.; Singh, Pushpendra P.; Montagnoli, G.; Mason, P.; Scarlassara, F.; Courtin, S.; Goasduff, A.; Haas, F.; Szilner, S.

    2010-03-15

    Near- and sub-barrier fusion cross sections have been measured for the system {sup 58}Ni+{sup 54}Fe, and the fusion barrier distribution has been extracted. The measured cross sections cover the range from approx =1 mub up to around 500 mb. Close analogies are found between the extracted barrier distribution and the available data on {sup 58}Ni+{sup 60}Ni, indicating the dominating influence of complex surface vibrations on the fusion of {sup 58}Ni+{sup 54}Fe. The present data on {sup 58}Ni+{sup 54}Fe are well reproduced by standard coupled-channels calculations in the measured energy range, including quadrupole and octupole phonons in both colliding nuclei.

  1. Ethanol assisted reduction and nucleation of ferromagnetic Co and Ni nanocrystalline particles

    SciTech Connect (OSTI)

    Huba, ZJ; Carpenter, EE

    2013-01-01

    In this report, we demonstrate the ability of ethanol to act as a solvent and reducing agent to nucleate nanocrystalline Co and Ni particles. Under solvothermal conditions, Co and Ni particles can be produced at 200 degrees C. The Ni and Co particles crystallized into FCC and a mixture of FCC and HCP crystal phases, respectively. Ni particles possessed a spherical morphology with diameters in the range of 200 nm to 300 nm. Co particles took on an ellipsoidal morphology, with diameters greater than 500 nm. Magnetizations for the Ni and Co particles were commensurate with bulk values, showing their high crystallinity and the presence of little oxide impurity. By finding inexpensive solvents with a lowered environmental impact, steps towards a "greener" synthetic process for ferromagnetic nanoparticles can be established.

  2. Hydrothermal synthesis and electrochemical performance of NiO microspheres with different nanoscale building blocks

    SciTech Connect (OSTI)

    Wang Ling; Hao Yanjing; Zhao Yan; Lai Qiongyu; Xu Xiaoyun

    2010-11-15

    NiO microspheres were successfully obtained by calcining the Ni(OH){sub 2} precursor, which were synthesized via the hydrothermal reaction of nickel chloride, glucose and ammonia. The products were characterized by TGA, XRD and SEM. The influences of glucose and reaction temperature on the morphologies of NiO samples were investigated. Moreover, the possible growth mechanism for the spherical morphology was proposed. The charge/discharge test showed that the as-prepared NiO microspheres composed of nanoparticles can serve as an ideal electrode material for supercapacitor due to the spherical hollow structure. -- Graphical Abstract: Fig. 5 is the SEM image of NiO that was prepared in the different hydrothermal reaction temperatures. It showed that reaction temperature played a crucial role for the morphology of products.

  3. Fabrication of NiO thin film electrode for supercapacitor applications

    SciTech Connect (OSTI)

    Mali, V. V.; Navale, S. T.; Chougule, M. A.; Khuspe, G. D.; Godse, P. R.; Patil, V. B.; Pawar, S. A.

    2014-04-24

    Nanocrystalline NiO electrode is successfully electrosynthesized for supercapacitor application. The nanocrystalline NiO electrode is characterized using scanning electron microscope (SEM). Nickel oxide is a highly porous and the film surface looked smooth and composed of fine elongated particles. The supercapacitive performance of NiO electrode is tested using cyclic voltammetry (C-V) technique in 0.5M Na{sub 2}S{sub 2}O{sub 3} electrolyte within potential range of ?1.2 to +1.2 V. The effect of scan rate on the capacitance of NiO electrode is studied. The highest specific capacitance of 439 Fg{sup ?1} at the voltage scan rate of 50mVs{sup ?1} is achieved. Additionally stability and chargingdischarging of NiO electrode are studied.

  4. Eutectic bonding of a Ti sputter coated, carbon aerogel wafer to a Ni foil

    SciTech Connect (OSTI)

    Jankowski, A.F.; Hayes, J.P.; Kanna, R.L.

    1994-06-01

    The formation of high energy density, storage devices is achievable using composite material systems. Alternate layering of carbon aerogel wafers and Ni foils with rnicroporous separators is a prospective composite for capacitor applications. An inherent problem exists to form a physical bond between Ni and the porous carbon wafer. The bonding process must be limited to temperatures less than 1000{degrees}C, at which point the aerogel begins to degrade. The advantage of a low temperature eutectic in the Ni-Ti alloy system solves this problem. Ti, a carbide former, is readily adherent as a sputter deposited thin film onto the carbon wafer. A vacuum bonding process is then used to join the Ni foil and Ti coating through eutectic phase formation. The parameters required for successfld bonding are described along with a structural characterization of the Ni foil-carbon aerogel wafer interface.

  5. Investigation of the second discharge plateau of the {beta}(III)-NiOOH/{beta}(II)-Ni(OH){sub 2} system

    SciTech Connect (OSTI)

    Leger, C.; Tessier, C.; Menetrier, M.; Denage, C.; Delmas, C. |

    1999-03-01

    The galvanostatic reduction of the nickel hydroxide electrode is known to proceed at two successive potentials without this phenomenon being well understood. In this paper the authors prove that this second discharge plateau is unrelated to oxygen reduction and that it can be observed in the absence of the {gamma}-NiOOH hydrated phase. Some earlier studies have connected it to the phase diagram of the {beta}(III)/{beta}(II) system. Using highly precise X-ray measurements, the authors demonstrate that the latter is quite different from the one commonly used. They then interpret the unusual shapes of potential relaxation curves during the lower discharge plateau. Measurements over a wide range of current density (four orders of magnitude) yield experimental clues for an original interpretation of the second discharge plateau based on the dynamics of the discharge process. They suggest that the second plateau is due to the existence of a phase close to Ni(OH){sub 2}, which is not ionically conductive but (poorly) electronically conductive, in the vicinity of the current collector.

  6. Microstructure and thermal conductivity of surfactant-free NiO nanostructures

    SciTech Connect (OSTI)

    Sahoo, Pranati; Misra, Dinesh K.; Salvador, Jim; Makongo, Julien P.A.; Chaubey, Girija S.; Takas, Nathan J.; Wiley, John B.; Poudeu, Pierre F.P.

    2012-06-15

    High purity, nanometer sized surfactant-free nickel oxide (NiO) particles were produced in gram scale using a solution combustion method and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), gas pycnometry and gas adsorption analysis (BET). The average particle size of the as-synthesized NiO increases significantly with the preheating temperature of the furnace, while the specific surface area decreases. A BET specific surface area of {approx}100 m{sup 2}/g was obtained for NiO nanoparticles with size as small as 3 nm synthesized at 300 Degree-Sign C. The thermal conductivity ({kappa}) of pressed pellets of the synthesized NiO nanoparticles obtained using spark plasma sintering (SPS) and uniaxial hot pressing is drastically decreased ({approx}60%) compared to that of NiO single crystal. This strong reduction in {kappa} with particle size suggests the suitability of the synthesized surfactant-free NiO nanoparticles for use as nanoinclusions when designing high performance materials for waste heat recovery. - Graphical abstract: Highly efficient phonon scattering by surfactant-free NiO nanostructures obtained by solution combustion of a mixture of nickel (II) nitrate hexahydrate (oxidizer) and urea (fuel) at various temperatures. Highlights: Black-Right-Pointing-Pointer Fast synthesis of surfactant-free NiO nanoparticles with controllable size. Black-Right-Pointing-Pointer High specific surface area for NiO nanoparticles with size range from 3 to 7 nm. Black-Right-Pointing-Pointer Strong reduction of the thermal conductivity with decreasing particle size. Black-Right-Pointing-Pointer NiO as nanoinclusions in high performance materials for energy conversion.

  7. High Temperature Oxidation Behavior of gamma-Ni+gamma'-Ni3Al Alloys and Coatings Modified with Pt and Reactive Elements

    SciTech Connect (OSTI)

    Nan Mu

    2007-12-01

    Materials for high-pressure turbine blades must be able to operate in the high-temperature gases (above 1000 C) emerging from the combustion chamber. Accordingly, the development of nickel-based superalloys has been constantly motivated by the need to have improved engine efficiency, reliability and service lifetime under the harsh conditions imposed by the turbine environment. However, the melting point of nickel (1455 C) provides a natural ceiling for the temperature capability of nickel-based superalloys. Thus, surface-engineered turbine components with modified diffusion coatings and overlay coatings are used. Theses coatings are capable of forming a compact and adherent oxide scale, which greatly impedes the further transport of reactants between the high-temperature gases and the underlying metal and thus reducing attack by the atmosphere. Typically, these coatings contain {beta}-NiAl as a principal constituent phase in order to have sufficient aluminum content to form an Al{sub 2}O{sub 3} scale at elevated temperatures. The drawbacks to the currently-used {beta}-based coatings, such as phase instabilities, associated stresses induced by such phase instabilities, and extensive coating/substrate interdiffusion, are major motivations in this study to seek next-generation coatings. The high-temperature oxidation resistance of novel Pt + Hf-modified {gamma}-Ni + {gamma}-Ni{sub 3}Al-based alloys and coatings were investigated in this study. Both early-stage and 4-days isothermal oxidation behavior of single-phase {gamma}-Ni and {gamma}{prime}-Ni{sub 3}Al alloys were assessed by examining the weight changes, oxide-scale structures, and elemental concentration profiles through the scales and subsurface alloy regions. It was found that Pt promotes Al{sub 2}O{sub 3} formation by suppressing the NiO growth on both {gamma}-Ni and {gamma}{prime}Ni{sub 3}Al single-phase alloys. This effect increases with increasing Pt content. Moreover, Pt exhibits this effect even at

  8. Undercooled and rapidly quenched Ni-Mo alloys

    SciTech Connect (OSTI)

    Tewari, S.N.; Glasgow, T.K.

    1986-01-01

    Hypoeutectic, eutectic, and hypereutectic nickel-molybdenum alloys were rapidly solidified by both bulk undercooling and melt spinning techniques. Alloys were undercooled in both electromagnetic levitation and differential thermal analysis equipment. The rate of recalescence depended upon the degree of initial undercooling and the nature (faceted or nonfaceted) of the primary nucleating phase. Alloy melts were observed to undercool more in the presence of primary Beta (NiMo intermetallic) phase than in gamma (fcc solid solution) phase. Melt spinning resulted in an extension of molybdenum solid solubility in gamma nickel, from 28 to 37.5 at % Mo. Although the microstructures observed by undercooling and melt spinning were similar the microsegregation pattern across the gamma dendries was different. The range of microstructures evolved was analyzed in terms of the nature of the primary phase to nucleate, its subsequent dendritic growth, coarsening and fragmentation, and final solidification of interfenderitic liquid.

  9. Low Temperature Scaling of the Susceptibility of Ni Films

    SciTech Connect (OSTI)

    Song, X. H.; Zhang, Xiaoguang; Fan, J.; Jin, Y. R.; Su, S. K.; Zhang, D. L.

    2008-03-01

    Measurement of low field ac susceptibility of Ni thin films over the temperature range 5-300K reveals a surprising power law scaling. The temperature dependent part of the normalized susceptibility, $\\chi_\\parallel/M_S-\\chi_{\\rm rot}/M_S$, where $\\chi_\\parallel$ is the initial susceptibility for in-plane magnetization, $\\chi_{\\rm rot}$ is the domain rotation contribution, and $M_S$ is the saturation magnetization, scales with the nonlinear reduced temperature as $t^{-2}$ over the entire temperature range, where $t=(T-T_C)/(T+T_C)$ and $T_C$ is the Curie temperature. Thickness and reduced temperature dependences are completely decoupled. This result implies that domain wall motion does not contribute to the low field susceptibility.

  10. Properties of Ni-Al under shock loading

    SciTech Connect (OSTI)

    Koskelo, A. C.; McClellan, K. J.; Brooks, J. D.; Paisley, Dennis L.; Swift, D. C.

    2002-01-01

    New models for the dynamic response of materials will be based increasingly on better understanding and representation of processes occurring at the microstructural level. These developments require advances in diagnostics and models which can be applied explicitly to microstructural response. Various phenomena occur at the microstructural level which are generally ignored or averaged out in continuum-level models. One example of such 'irregular hydrodynamics' is the roughness imparted to a shock wave as it propagates through a polycrystalline material. We have developed imaging techniques to study spatial variations in shock propagation through polycrystalline materials. In order to interpret spatially-resolved data from polycrystal samples, we need to compare with simulations which represent the microstructure. Here we describe work undertaken to develop a model of the dynamic response of individual grains. The material chosen was Ni-Al alloy, because it exhibits a relatively large degree of elastic anisotropy, and it is relatively easy to manufacture.

  11. In situ carbonyl extraction of Ni from gaseous diffusion cells

    SciTech Connect (OSTI)

    Visnapuu, A. [USBM Salt Lake Research Center, Salt Lake City, UT (United States); Hollenberg, G.W. [Battelle Pacific Northwest Lab., Richland, WA (United States); Bundy, R.D. [Battelle Memorial Institute, Oak Ridge, TN (United States)

    1995-12-31

    This paper discusses the use of carbonyl processing technology for recovery of nickel from uranium isotope separation diffusion cells, and potential applications to recover nickel, iron, chromium, cobalt, and other carbonyl forming metals from nuclear waste while reducing the volume of the high level residue for more economic disposal. Nickel powder was carbonylated under static and dynamic conditions using only carbon monoxide to determine if the nickel powder would react rapidly enough to require no promoter. Nickel to Ni(CO){sub 4} conversion was realized in all cases and nickel metal was vapor deposited in the thermal decomposer, but the conversion rates in all cases the reaction were too slow for practical recovery. Addition of hydrogen sulfide gas as a promoter increased the conversion rate more than 500-fold over conversion with no promoter. Test summaries are provided in the paper; results indicate that promoter activated carbonylation is a viable approach for recovery of nickel from uranium isotope diffusion cells.

  12. A semisynthetic strategy leads to alteration of the backbone amidate ligand in the NiSOD active site

    SciTech Connect (OSTI)

    Campeciño, Julius O.; Dudycz, Lech W.; Tumelty, David; Berg, Volker; Cabelli, Diane E.; Maroney, Michael J.

    2015-07-01

    Computational investigations have implicated the amidate ligand in nickel superoxide dismutase (NiSOD) in stabilizing Ni-centered redox catalysis and in preventing cysteine thiolate ligand oxidation. To test these predictions, we have used an experimental approach utilizing a semisynthetic scheme that employs native chemical ligation of a pentapeptide (HCDLP) to recombinant S. coelicolor NiSOD lacking these N-terminal residues, NΔ5-NiSOD. Wild-type enzyme produced in this manner exhibits the characteristic spectral properties of recombinant WT-NiSOD and is as catalytically active. The semisynthetic scheme was also employed to construct a variant where the amidate ligand was converted to a secondary amine, H1*-NiSOD, a novel strategy that retains a backbone N-donor atom. The H1*-NiSOD variant was found to have only ~1% of the catalytic activity of the recombinant wild-type enzyme, and had altered spectroscopic properties. X-ray absorption spectroscopy reveals a four-coordinate planar site with N2S2-donor ligands, consistent with electronic absorption spectroscopic results indicating that the Ni center in H1*-NiSOD is mostly reduced in the as-isolated sample, as opposed to 50:50 Ni(II)/Ni(III) mixture that is typical for the recombinant wild-type enzyme. The EPR spectrum of as-isolated H1*-NiSOD accounts for ~11% of the Ni in the sample and is similar to WT-NiSOD, but more axial, with gz < gx,y. 14N-hyperfine is observed on gzNi(III) complex. As a result, the altered electronic properties and implications for redox catalysis are discussed in light of predictions based on synthetic and computational models.

  13. A semisynthetic strategy leads to alteration of the backbone amidate ligand in the NiSOD active site

    SciTech Connect (OSTI)

    Campecio, Julius O.; Dudycz, Lech W.; Tumelty, David; Berg, Volker; Cabelli, Diane E.; Maroney, Michael J.

    2015-07-01

    Computational investigations have implicated the amidate ligand in nickel superoxide dismutase (NiSOD) in stabilizing Ni-centered redox catalysis and in preventing cysteine thiolate ligand oxidation. To test these predictions, we have used an experimental approach utilizing a semisynthetic scheme that employs native chemical ligation of a pentapeptide (HCDLP) to recombinant S. coelicolor NiSOD lacking these N-terminal residues, N?5-NiSOD. Wild-type enzyme produced in this manner exhibits the characteristic spectral properties of recombinant WT-NiSOD and is as catalytically active. The semisynthetic scheme was also employed to construct a variant where the amidate ligand was converted to a secondary amine, H1*-NiSOD, a novel strategy that retains a backbone N-donor atom. The H1*-NiSOD variant was found to have only ~1% of the catalytic activity of the recombinant wild-type enzyme, and had altered spectroscopic properties. X-ray absorption spectroscopy reveals a four-coordinate planar site with N2S2-donor ligands, consistent with electronic absorption spectroscopic results indicating that the Ni center in H1*-NiSOD is mostly reduced in the as-isolated sample, as opposed to 50:50 Ni(II)/Ni(III) mixture that is typical for the recombinant wild-type enzyme. The EPR spectrum of as-isolated H1*-NiSOD accounts for ~11% of the Ni in the sample and is similar to WT-NiSOD, but more axial, with gz < gx,y. 14N-hyperfine is observed on gzNi(III) complex. As a result, the altered electronic properties and implications for redox catalysis are discussed in light of predictions based on synthetic and computational models.

  14. (001) Oriented piezoelectric films prepared by chemical solution deposition on Ni foils

    SciTech Connect (OSTI)

    Yeo, Hong Goo Trolier-McKinstry, Susan

    2014-07-07

    Flexible metal foil substrates are useful in some microelectromechanical systems applications including wearable piezoelectric sensors or energy harvesters based on Pb(Zr,Ti)O₃ (PZT) thin films. Full utilization of the potential of piezoelectrics on metal foils requires control of the film crystallographic texture. In this study, (001) oriented PZT thin films were grown by chemical solution deposition (CSD) on Ni foil and Si substrates. Ni foils were passivated using HfO₂ grown by atomic layer deposition in order to suppress substrate oxidation during subsequent thermal treatment. To obtain the desired orientation of PZT film, strongly (100) oriented LaNiO₃ films were integrated by CSD on the HfO₂ coated substrates. A high level of (001) LaNiO₃ and PZT film orientation were confirmed by X-ray diffraction patterns. Before poling, the low field dielectric permittivity and loss tangents of (001) oriented PZT films on Ni are near 780 and 0.04 at 1 kHz; the permittivity drops significantly on poling due to in-plane to out-of-plane domain switching. (001) oriented PZT film on Ni displayed a well-saturated hysteresis loop with a large remanent polarization ~36 μC/cm², while (100) oriented PZT on Si showed slanted P-E hysteresis loops with much lower remanent polarizations. The |e{sub 31,f}| piezoelectric coefficient was around 10.6 C/m² for hot-poled (001) oriented PZT film on Ni.

  15. Carbon-Supported IrNi Core-Shell Nanoparticles: Synthesis Characterization and Catalytic Activity

    SciTech Connect (OSTI)

    K Sasaki; K Kuttiyiel; L Barrio; D Su; A Frenkel; N Marinkovic; D Mahajan; R Adzic

    2011-12-31

    We synthesized carbon-supported IrNi core-shell nanoparticles by chemical reduction and subsequent thermal annealing in H{sub 2}, and verified the formation of Ir shells on IrNi solid solution alloy cores by various experimental methods. The EXAFS analysis is consistent with the model wherein the IrNi nanoparticles are composed of two-layer Ir shells and IrNi alloy cores. In situ XAS revealed that the Ir shells completely protect Ni atoms in the cores from oxidation or dissolution in an acid electrolyte under elevated potentials. The formation of Ir shell during annealing due to thermal segregation is monitored by time-resolved synchrotron XRD measurements, coupled with Rietveld refinement analyses. The H{sub 2} oxidation activity of the IrNi nanoparticles was found to be higher than that of a commercial Pt/C catalyst. This is predominantly due to Ni-core-induced Ir shell contraction that makes the surface less reactive for IrOH formation, and the resulting more metallic Ir surface becomes more active for H{sub 2} oxidation. This new class of core-shell nanoparticles appears promising for application as hydrogen anode fuel cell electrocatalysts.

  16. Phase relations and structural features in the system Ni-Zn-B

    SciTech Connect (OSTI)

    Malik, Z.; Grytsiv, A.; Rogl, P.; Giester, G.; Bursik, J.

    2013-02-15

    Phase relations for the system Ni-Zn-B have been established in the isothermal section at 800 Degree-Sign C based on X-ray powder diffraction and electron microprobe analyses of about 60 samples, which have been prepared by hot pressing of pre-annealed powder compacts of arc-melted master alloys Ni{sub x}B{sub y} and Zn-filings. Six ternary compounds (labeled {tau}{sub 1} to {tau}{sub 6}) were found to exist, which in some cases exhibit considerable mutual solid solubilities mostly as an exchange of Ni-Zn at constant B-content, but in the case of the so-called {tau}-phase {tau}{sub 1}-(Ni{sub 1-x}Zn{sub x}){sub 21}[Zn{sub 1-y-z}{open_square}{sub y}(B{sub 4}){sub z}]{sub 2}B{sub 6} (0.07{<=}x{<=}0.11, 0.07{<=}y{<=}0.53, 0{<=}z{<=}0.3) also with Zn/B substitution. Single crystal X-ray data analysis for the composition x=0.07, y=0.125, z=0.30, and a=1.05800(3) nm confirmed the Cr{sub 23}C{sub 6} type with space group Fm3{sup Macron }m, but revealed partial replacement of Zn-atoms by B{sub 4}-tetrahedra (R{sub F}=0.014). Whereas Ni/Zn exchange (at constant B-content) ranges at about 4-5 at% for {tau}{sub 4}-Ni{sub 3}ZnB{sub 2} and {tau}{sub 5}-Ni{sub 48}Zn{sub 32}B{sub 20}, it is below 3 at% for {tau}{sub 2}-Ni{sub 12}ZnB{sub 8-x} (x=0.43), {tau}{sub 3}-Ni{sub 21}Zn{sub 2}B{sub 20} and {tau}{sub 6}-Ni{sub 47}Zn{sub 23}B{sub 30}. The crystal structures of {tau}{sub 2}-Ni{sub 12}ZnB{sub 8-x} (x=0.43; Ni{sub 12}AlB{sub 8} type), {tau}{sub 3}-Ni{sub 21}Zn{sub 2}B{sub 20} (own type) and {tau}{sub 4}-Ni{sub 3}ZnB{sub 2} (own type) have been determined in our foregoing paper [8]. Due to the non-availability of suitable single crystals, the crystal structures of {tau}{sub 5}-Ni{sub 48}Zn{sub 32}B{sub 20} (body-centered orthorhombic; a=1.6(2) nm, b=0.63(7) nm, and c=0.27(0) nm, determined from TEM) and of {tau}{sub 6}-Ni{sub 47}Zn{sub 23}B{sub 30} have not been elucidated yet. Phase equilibria at 800 Degree-Sign C are dominated by a large three-phase field ({beta}B)+Ni{sub 2}Zn

  17. On characterisation of wire-arc-plasma-sprayed Ni on alumina substrate

    SciTech Connect (OSTI)

    Laik, A.; Chakravarthy, D.P.; Kale, G.B. . E-mail: gbkale@apsara.barc.ernet.in

    2005-08-15

    A study was carried out on metal-ceramic bonding produced by the technique of wire-arc-plasma spraying of Ni on Al{sub 2}O{sub 3} substrate. The Ni layer and the Ni/Al{sub 2}O{sub 3} interface were characterised using optical and electro-optic techniques. The plasma-deposited Ni layer shows a uniform lamellar microstructure throughout the cross-section. The metal-ceramic interface was found to be well bonded with no pores, flaws or cracks in the as-sprayed condition. The optical metallography and concentration profiles established with the help of an electron probe microanalyser confirmed the absence of any intermediate phase at the interface. An annealing treatment at 1273 K for 24 h on the plasma-coated samples did not result in formation of any intermetallic compound or spinel at the Ni/Al{sub 2}O{sub 3} interface. This indicates that the oxygen picked up by Ni during the spraying operation is less than the threshold value required to form the spinel NiAl{sub 2}O{sub 4}.

  18. NREL Improves Hole Transport in Sensitized CdS-NiO Nanoparticle Photocathodes (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-01-01

    Significantly improved charge-collection efficiencies result from a general chemical approach to synthesizing photocathodes. It has been reported that a dye-sensitized nickel oxide (NiO) photocathode, when coupled to a dye-sensitized photoanode, could significantly increase overall solar conversion efficiency. However, the conversion efficiencies of these cells are still low. There has been much effort to improve the conversion efficiency by fabricating films with improved properties and developing more effective sensitizing dyes for p-type NiO. One of the factors limiting the use of NiO for solar cell application is the low hole conductivity in p-NiO. A team of researchers from the National Renewable Energy Laboratory (NREL) developed a general chemical approach to synthesize NiO-cadmium sulfide (CdS) core-shell nanoparticle films as photocathodes for p-type semiconductor-sensitized solar cells. Compared to dye-sensitized NiO photocathodes, the CdS-sensitized NiO cathodes exhibited two orders of magnitude faster hole transport (attributable to the passivation of surface traps by the CdS) and almost 100% charge-collection efficiencies.

  19. Fabrication of hollow mesoporous NiO hexagonal microspheres via hydrothermal process in ionic liquid

    SciTech Connect (OSTI)

    Zhao, Jinbo; School of Materials Science and Engineering, Shandong University, 250061, Jinan ; Wu, Lili; School of Materials Science and Engineering, Shandong University, 250061, Jinan ; Zou, Ke; School of Materials Science and Engineering, Shandong University, 250061, Jinan

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer Ni(OH){sub 2} precursors were synthesized in ionic liquid and water solution by hydrothermal method. Black-Right-Pointing-Pointer NiO hollow microspheres were prepared by thermal treatment of Ni(OH){sub 2} precursors. Black-Right-Pointing-Pointer NiO hollow microspheres were self-assembled by mesoporous cubic and hexagonal nanocrystals with high specific surface area. Black-Right-Pointing-Pointer The mesoporous structure is stable at 773 K. Black-Right-Pointing-Pointer The ionic liquid absorbed on the O-terminate surface of the crystals to form hydrogen bond and played key roles in determining the final shape of the NiO novel microstructure. -- Abstract: The novel NiO hexagonal hollow microspheres have been successfully prepared by annealing Ni(OH){sub 2}, which was synthesized via an ionic liquid-assisted hydrothermal method. The samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), transmission electron microscopy (TEM), N{sub 2} adsorption-desorption and Fourier transform infrared spectrometer (FTIR). The results show that the hollow NiO microstructures are self-organized by mesoporous cubic and hexagonal nanocrystals. The mesoporous structure possessed good thermal stability and high specific surface area (ca. 83 m{sup 2}/g). The ionic liquid 1-butyl-3methylimidazolium tetrafluoroborate ([Bmim][BF{sub 4}]) was found to play a key role in controlling the morphology of NiO microstructures during the hydrothermal process. The special hollow mesoporous architectures will have potential applications in many fields, such as catalysts, absorbents, sensors, drug-delivery carriers, acoustic insulators and supercapacitors.

  20. Structure Analysis of a Precipitate Phase in an Ni-Rich High Temperature NiTiHf Shape Memory Alloy

    SciTech Connect (OSTI)

    Yang, Fan; Coughlin, D. R.; Phillips, Patrick J.; Yang, L.; Devaraj, Arun; Kovarik, Libor; Noebe, Ronald D.; Mills, M. J.

    2013-03-22

    Thermal aging of the high temperature shape memory alloy 50.3Ni-29.7Ti-20Hf (at.%) introduces a novel precipitate phase, which plays an important role in improving shape memory properties. The precipitate phase was investigated by conventional electron diffraction, high resolution scanning transmission electron microscopy (STEM) and three dimensional atom probe tomography. An unrelaxed orthorhombic atomic structural model is proposed based on these observations. This model was subsequently relaxed by ab initio calculations. As a result of the relaxation, atom shuffle displacements occur, which in turn yields improved agreement with the STEM images. The relaxed structure, which is termed the “H-phase”, has also been verified to be thermodymanically stable at 0 K.

  1. Improved synthesis and crystal structure of the flexible pillared layer porous coordination polymer: Ni(1,2-bis(4-pyridyl)ethylene)[Ni(CN)4

    SciTech Connect (OSTI)

    Wong-Ng, W.; Culp, J. T.; Chen, Y. S.; Zavalij, P.; Espinal, L.; Siderius, D. W.; Allen, A. J.; Scheins, S.; Matranga, C.

    2013-01-01

    This paper reports our synthesis of flexible coordination polymer, Ni(L)[Ni(CN)4], (L = 1,2-bis(4-pyridyl)ethylene (nicknamed bpene)), and its structural characterization using synchrotron single crystal X-ray diffraction. The structure of the purplish crystals has been determined to be monoclinic, space group P21/m, a = 13.5941(12) Å, b = 14.3621(12) Å, c = 14.2561(12) Å, β = 96.141(2)°, V = 2767.4(4) Å3, Z = 4, Dc = 1.46 g cm-1. Ni(bpene)[Ni(CN)4] assumes a pillared layer structure with layers defined by Ni[Ni(CN)4]n nets and bpene ligands acting as pillars. With the present crystallization technique which involves the use of concentrated ammonium hydroxide solution and dimethyl sulfoxide (DMSO), disordered free bpene ligands and solvents of crystallization (DMSO and water molecules) occupy the pores, resulting in a formula of Ni(bpene)[Ni(CN)4](1/2)bpene∙DMSO2H2O, or Ni2N7C24H25SO3. Without the inclusion of free bpene ligands and solvent molecules, the free volume is approximately 61% of the total volume; this free volume fraction is reduced to 50% with the free ligands present. Pores without the free ligands were found to have a local diameter of 5.7 Å and a main aperture of 3.5 Å. Based on the successful crystal synthesis, we also devised a new bulk synthetic technique which yielded a polycrystalline material with a significantly improved CO2 uptake as compared to the originally reported powder material. The improved synthetic technique yielded a polycrystalline material with 40% higher CO2 uptake compared to the previously reported powder material. An estimated 14.4 molecules of CO2 per unit cell was obtained.

  2. Effects of anode materials on resistive characteristics of NiO thin films

    SciTech Connect (OSTI)

    Jia, Ze; Wang, Linkai; Zhang, Naiwen; Ren, Tianling; Liou, Juin J.

    2013-01-28

    This letter shows that the NiO-based structure with different anodes has different resistive switching properties. A conical conductive filament (CF) model is proposed for oxygen vacancies distributed in NiO films. Modeling analysis reveals much larger dissolution velocity of CF near anodes than near cathodes during the reset process. Different interfaces shown in Auger electron spectroscopy can be bound with the model to reveal that CF is dissolved in the structure with Pt or Au as anodes, while CF remains constant if the anode material is Ti or Al, which can explain whether switching properties occur in the specific NiO-based structures.

  3. AB INITIO STUDIES OF COKE FORMATION ON NI CATALYSTS DURING METHANE REFORMING

    SciTech Connect (OSTI)

    David S. Sholl

    2003-09-25

    The atomic-scale processes that control the formation of carbon deposits on Ni catalysts in reforming applications are poorly understood. Ab initio Density Functional Theory calculations have been used to examine several key elementary steps in the complex network of chemical reactions that precedes carbon formation on practical catalysts. Attention has been focused on the disproportionation of CO. A comparative study of this reaction on flat and stepped crystal planes of Ni has provided the first direct evidence that surface carbon formation is driven by elementary reactions occurring at defect sites on Ni catalysts.

  4. Observation of spectral evolution during the formation of a Ni2 kondo molecule

    SciTech Connect (OSTI)

    Madhavan, V.; Jamneala, T.; Nagaoka, K.; Chen, W.; Li, Je-Luen; Louie, Steven G.; Crommie, M.F.

    2002-04-15

    We have used atomic manipulation and scanning tunneling spectroscopy to study the evolution in electronic properties that occurs as two Ni atoms are merged into a single magnetic molecule on Au(111). We observe energetic shifting of molecular d-orbitals and a strong decrease in the molecular Kondo temperature as Ni-Ni separation is reduced to 3.4+ or -0.3Angstroms. These results are qualitatively explained by a combination of spin-1/2-s-d model and density-functional calculations.

  5. Implications of NiMH Hysteresis on HEV Battery Testing and Performance

    SciTech Connect (OSTI)

    Motloch, Chester George; Belt, Jeffrey R; Hunt, Gary Lynn; Ashton, Clair Kirkendall; Murphy, Timothy Collins; Miller, Ted J.; Coates, Calvin; Tataria, H. S.; Lucas, Glenn E.; Duong, T.Q.; Barnes, J.A.; Sutula, Raymond

    2002-08-01

    Nickel Metal-Hydride (NiMH) is an advanced high-power battery technology that is presently employed in Hybrid Electric Vehicles (HEVs) and is one of several technologies undergoing continuing research and development by FreedomCAR. Unlike some other HEV battery technologies, NiMH exhibits a strong hysteresis effect upon charge and discharge. This hysteresis has a profound impact on the ability to monitor state-of-charge and battery performance. Researchers at the Idaho National Engineering and Environmental Laboratory (INEEL) have been investigating the implications of NiMH hysteresis on HEV battery testing and performance. Experimental results, insights, and recommendations are presented.

  6. Method for measurement of diffusivity: Calorimetric studies of Fe/Ni multilayer thin films

    SciTech Connect (OSTI)

    Liu, JX; Barmak, K

    2015-07-15

    A calorimetric method for the measurement of diffusivity in thin film multilayers is introduced and applied to the Fe Ni system. Using this method, the diffusivity in [Fe (25 nm)/Ni (25 nm)](20) multilayer thin films is measured as 4 x 10(-3)exp(-1.6 +/- 0.1 eV/ k(B)T) cm(2)/s, respectively. The diffusion mechanism in the multilayers and its relevance to laboratory synthesis of L1(0) ordered FeNi are discussed. (C) 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  7. Phonon densities of states of face-centered-cubic Ni-Fe alloys

    SciTech Connect (OSTI)

    Lucas, Matthew; Mauger, L; Munoz, Jorge A.; Halevy, I; Horwath, J; Semiatin, S L; Leontsev, S. O.; Stone, Matthew B; Abernathy, Douglas L; Xiao, Yuming; Chow, P; Fultz, B.

    2013-01-01

    Inelastic neutron scattering and nuclear resonant inelastic x-ray scattering were used to determine the phonon densities of states of face-centered-cubic Ni-Fe alloys. Increasing Fe concentration results in an average softening of the phonon modes. Chemical ordering of the Ni0.72Fe0.28 alloy results in a reduction of the partial vibrational entropy of the Fe atoms but does not significantly change the partial vibrational entropy of the Ni atoms. Changes in the phonon densities of states with composition and chemical ordering are discussed and analyzed with a cluster expansion method.

  8. Structural evolution in Ti-Cu-Ni metallic glasses during heating

    SciTech Connect (OSTI)

    Gargarella, P.; Pauly, S.; Stoica, M.; Khn, U.; Vaughan, G.; Afonso, C. R. M.; Eckert, J.

    2015-01-01

    The structural evolution of Ti{sub 50}Cu{sub 43}Ni{sub 7} and Ti{sub 55}Cu{sub 35}Ni{sub 10} metallic glasses during heating was investigated by in-situ synchrotron X-ray diffraction. The width of the most intense diffraction maximum of the glassy phase decreases slightly during relaxation below the glass transition temperature. Significant structural changes only occur above the glass transition manifesting in a change in the respective peak positions. At even higher temperatures, nanocrystals of the shape memory B2-Ti(Cu,Ni) phase precipitate, and their small size hampers the occurrence of a martensitic transformation.

  9. Effects of aging on the characteristics of TiNiPd shape memory alloy thin films

    SciTech Connect (OSTI)

    Zhang Congchun

    2008-07-15

    TiNiPd thin films have been deposited on glass substrate using R.F. magnetron sputtering. Effects of annealing and aging on the microstructure, phase transformation behaviors and shape memory effects of these thin films have been studied by X-ray diffractometry, differential scanning calorimeter, tensile tests and internal friction characteristics. The TiNiPd thin films annealed at 750 deg. C exhibit uniform martensite/austenite transformations and shape memory effect. Aging at 450 deg. C for 1 h improved the uniformity of transformations and shape memory effect. Long time aging decreased transformation temperatures and increased the brittleness of TiNiPd thin films.

  10. Unoccupied electronic structure of Ni2MnGa ferromagnetic shape memory alloy

    SciTech Connect (OSTI)

    Maniraj, M.; D?Souza, S. W.; Rai, Abhishek; Schlagel, D. L.; Lograsso, T. A.; Chakrabarti, Aparna; Barman, S. R.

    2015-08-20

    Momentum resolved inverse photoemission spectroscopy measurements show that the dispersion of the unoccupied bands of Ni2MnGa is significant in the austenite phase. Furthermore, in the martensite phase, it is markedly reduced, which is possibly related to the structural transition to an incommensurate modulated state in the martensite phase. Finally, based on the first principle calculations of the electronic structure of NiMnGa, we show that the modification of the spectral shape with surface composition is related to change in the hybridization between the Mn 3d and Ni 3d-like states that dominate the unoccupied conduction band.

  11. CASL - Mixing and non-stoichiometry in Fe-Ni-Cr-Zn-O spinel compounds:

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

    Density functional theory calculations Mixing and non-stoichiometry in Fe-Ni-Cr-Zn-O spinel compounds: Density functional theory calculations Mixing and non-stoichiometry in Fe-Ni-Cr-Zn-O spinel compounds: Density functional theory calculations D.A. Andersson and C.R. Stanek Materials Science and Technology Division Los Alamos National Laboratory Density functional theory (DFT) calculations have been employed to better understand the thermodynamic properties of AB2O4 (where A=Fe2+, Ni2+ or

  12. Features of a priori heavy doping of the n-TiNiSn intermetallic semiconductor

    SciTech Connect (OSTI)

    Romaka, V. A.; Rogl, P.; Romaka, V. V.; Hlil, E. K.; Stadnyk, Yu. V.; Budgerak, S. M.

    2011-07-15

    The crystal structure, the distribution of electron density, and the energy, kinetic, and magnetic properties of the n-TiNiSn intermetallic semiconductor are investigated. It is shown that a priori doping of n-TiNiSn with donors originates from partial, up to 0.5 at %, redistribution of Ti and Ni atoms in crystallographic sites of Ti atoms. The correlation is established between the donor concentration, amplitude of modulation of the continuous energy bands, and degree of filling of low-scale fluctuation potential wells with charge carriers. The results obtained are discussed within the Shklovskii-Efros model of a heavily doped and compensated semiconductor.

  13. Significant Reduction in NiO Band Gap upon Formation of LixNi1?xO Alloys: Applications to Solar Energy Conversion

    SciTech Connect (OSTI)

    Alidoust, Nima; Toroker, Maytal; Keith, John A.; Carter, Emily A.

    2014-01-01

    Long-term sustainable solar energy conversion relies on identifying economical and versatile semiconductor materials with appropriate band structures for photovoltaic and photocatalytic applications (e.g., band gaps of ?1.52.0 eV). Nickel oxide (NiO) is an inexpensive yet highly promising candidate. Its charge-transfer character may lead to longer carrier lifetimes needed for higher efficiencies, and its conduction band edge is suitable for driving hydrogen evolution via water-splitting. However, NiOs large band gap (?4 eV) severely limits its use in practical applications. Our first-principles quantum mechanics calculations show band gaps dramatically decrease to ?2.0 eV when NiO is alloyed with Li2O. We show that LixNi1?xO alloys (with x=0.125 and 0.25) are p-type semiconductors, contain states with no impurity levels in the gap and maintain NiOs desirable charge-transfer character. Lastly, we show that the alloys have potential for photoelectrochemical applications, with band edges well-placed for photocatalytic hydrogen production and CO2 reduction, as well as in tandem dye-sensitized solar cells as a photocathode.

  14. A semisynthetic strategy leads to alteration of the backbone amidate ligand in the NiSOD active site

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

    Campeciño, Julius O.; Dudycz, Lech W.; Tumelty, David; Berg, Volker; Cabelli, Diane E.; Maroney, Michael J.

    2015-07-01

    Computational investigations have implicated the amidate ligand in nickel superoxide dismutase (NiSOD) in stabilizing Ni-centered redox catalysis and in preventing cysteine thiolate ligand oxidation. To test these predictions, we have used an experimental approach utilizing a semisynthetic scheme that employs native chemical ligation of a pentapeptide (HCDLP) to recombinant S. coelicolor NiSOD lacking these N-terminal residues, NΔ5-NiSOD. Wild-type enzyme produced in this manner exhibits the characteristic spectral properties of recombinant WT-NiSOD and is as catalytically active. The semisynthetic scheme was also employed to construct a variant where the amidate ligand was converted to a secondary amine, H1*-NiSOD, a novel strategymore » that retains a backbone N-donor atom. The H1*-NiSOD variant was found to have only ~1% of the catalytic activity of the recombinant wild-type enzyme, and had altered spectroscopic properties. X-ray absorption spectroscopy reveals a four-coordinate planar site with N2S2-donor ligands, consistent with electronic absorption spectroscopic results indicating that the Ni center in H1*-NiSOD is mostly reduced in the as-isolated sample, as opposed to 50:50 Ni(II)/Ni(III) mixture that is typical for the recombinant wild-type enzyme. The EPR spectrum of as-isolated H1*-NiSOD accounts for ~11% of the Ni in the sample and is similar to WT-NiSOD, but more axial, with gz < gx,y. 14N-hyperfine is observed on gz« less

  15. Contact-induced spin polarization of monolayer hexagonal boron nitride on Ni(111)

    SciTech Connect (OSTI)

    Ohtomo, Manabu; Entani, Shiro; Matsumoto, Yoshihiro; Naramoto, Hiroshi; Sakai, Seiji; Yamauchi, Yasushi; Kuzubov, Alex A.; Eliseeva, Natalya S.; Avramov, Pavel V.

    2014-02-03

    Hexagonal boron nitride (h-BN) is a promising barrier material for graphene spintronics. In this Letter, spin-polarized metastable de-excitation spectroscopy (SPMDS) is employed to study the spin-dependent electronic structure of monolayer h-BN/Ni(111). The extreme surface sensitivity of SPMDS enables us to elucidate a partial filling of the in-gap states of h-BN without any superposition of Ni 3d signals. The in-gap states are shown to have a considerable spin polarization parallel to the majority spin of Ni. The positive spin polarization is attributed to the π-d hybridization and the effective spin transfer to the nitrogen atoms at the h-BN/Ni(111) interface.

  16. Enhanced Thermal Stability of W-Ni-Al2O3 Cermet-Based Spectrally...

    Office of Scientific and Technical Information (OSTI)

    Solar Absorbers with Tungsten Infrared Reflectors Citation Details In-Document Search Title: Enhanced Thermal Stability of W-Ni-Al2O3 Cermet-Based Spectrally Selective Solar ...

  17. AB INITIO STUDIES OF COKE FORMATION ON NI CATALYSTS DURING METHANE REFORMING

    SciTech Connect (OSTI)

    David S. Sholl

    2004-09-25

    The atomic-scale processes that control the formation of carbon deposits on Ni catalysts in reforming applications are poorly understood. Ab initio Density Functional Theory calculations have been used to examine several key elementary steps in the complex network of chemical reactions that precedes carbon formation on practical catalysts. Attention has been focused on the disproportionation of CO. A comparative study of this reaction on flat and stepped crystal planes of Ni has provided the first direct evidence that surface carbon formation is driven by elementary reactions occurring at defect sites on Ni catalysts. The adsorption and diffusion of atomic H on several flat and stepped Ni surfaces has also been characterized experimentally.

  18. Ab Initio Studies of Coke Formation on Ni Catalysts During Methane Reforming

    SciTech Connect (OSTI)

    David S. Sholl

    2006-03-05

    The atomic-scale processes that control the formation of carbon deposits on Ni catalysts in reforming applications are poorly understood. Ab initio Density Functional Theory calculations have been used to examine several key elementary steps in the complex network of chemical reactions that precedes carbon formation on practical catalysts. Attention has been focused on the disproportionation of CO. A comparative study of this reaction on flat and stepped crystal planes of Ni has provided the first direct evidence that surface carbon formation is driven by elementary reactions occurring at defect sites on Ni catalysts. The adsorption and diffusion of atomic H on several flat and stepped Ni surfaces has also been characterized experimentally.

  19. A pseudo binary y-Gd solidification diagram for Ni-Cr-Mo-Gd alloys...

    Office of Scientific and Technical Information (OSTI)

    Title: A pseudo binary y-Gd solidification diagram for Ni-Cr-Mo-Gd alloys. No abstract prepared. Authors: Dupont, John Neuman 1 ; Minicozzi, Michael J. 1 ; Robino, Charles ...

  20. Pressure-Induced Structural Phase Transition in CeNi: X-ray and...

    Office of Scientific and Technical Information (OSTI)

    Pressure-Induced Structural Phase Transition in CeNi: X-ray and Neutron Scattering Studies and First-Principles Calculations Citation Details In-Document Search Title: ...

  1. Thickness dependence of hydrogen permeability for Ni-BaCe{sub...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Thickness dependence of hydrogen permeability for Ni-BaCesub 0.8Ysub 0.2Osub 3-delta. Citation Details In-Document Search Title: Thickness dependence of ...

  2. Unoccupied electronic structure of Ni2MnGa ferromagnetic shape...

    Office of Scientific and Technical Information (OSTI)

    shape memory alloy This content will become publicly available on August 20, 2016 Prev Next Title: Unoccupied electronic structure of Ni2MnGa ferromagnetic shape memory alloy ...

  3. Microstructural evaluation of NiTi-based films deposited by magnetron sputtering

    SciTech Connect (OSTI)

    Crăciunescu, Corneliu M. Mitelea, Ion Budău, Victor; Ercuţa, Aurel

    2014-11-24

    Shape memory alloy films belonging to the NiTi-based systems were deposited on heated and unheated substrates, by magnetron sputtering in a custom made system, and their structure and composition was analyzed using electron microscopy. Several substrates were used for the depositions: glass, Cu-Zn-Al, Cu-Al-Ni and Ti-NiCu shape memory alloy ribbons and kapton. The composition of the Ti-Ni-Cu films showed limited differences, compared to the one of the target and the microstructure for the DC magnetron sputtering revealed crystallized structure with features determined on peel off samples from a Si wafer. Both inter and transcrystalline fractures were observed and related to the interfacial stress developed on cooling from deposition temperature.

  4. Microstructure and Mechanical Properties of Two-Phase Fe30Ni20Mn20Al30...

    Office of Scientific and Technical Information (OSTI)

    Title: Microstructure and Mechanical Properties of Two-Phase Fe30Ni20Mn20Al30 Alloy Authors: Wu, Xiaolan 1 ; Baker, Ian 1 ; Wu, H 1 ; Miller, Michael K 2 ; More, Karren ...

  5. Thermal properties of Ni-substituted LaCoO{sub 3} perovskite

    SciTech Connect (OSTI)

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

    2014-04-24

    With the objective of exploring the unknown thermodynamic behavior of LaCo{sub 1?x}Ni{sub x}O{sub 3} family, we present here an investigation of the temperature-dependent (10K ? T ? 300K) thermodynamic properties of LaCo{sub 1?x}Ni{sub x}O{sub 3} (x=0.1, 0.3, 0.5). The specific heat of LaCoO3 with Ni doping in the perovskite structure at B-site has been studied by means of a Modified Rigid Ion Model (MRIM). This replacement introduces large cation variance at B-site hence the specific heat increases appreciably. We report here probably for the first time the cohesive energy, Reststrahlen frequency (?) and Debye temperature (?{sub D}) of LaCo{sub 1?x}Ni{sub x}O{sub 3} compounds.

  6. Electronic Structure and Lattice Dynamics of the Magnetic Shape Memory Alloy Co2NiGa

    SciTech Connect (OSTI)

    Siewert, M.; Shapiro, S.; Gruner, M.E.; Dannenberg, A.; Hucht, A.; Xu, G.; Schlagel, D.L.; Lograsso, T.A.; Entel1, P.

    2010-08-20

    In addition to the prototypical Ni-Mn-based Heusler alloys, the Co-Ni-Ga systems have recently been suggested as another prospective materials class for magnetic shape-memory applications. We provide a characterization of the dynamical properties of this material and their relation to the electronic structure within a combined experimental and theoretical approach. This relies on inelastic neutron scattering to obtain the phonon dispersion while first-principles calculations provide the link between dynamical properties and electronic structure. In contrast to Ni{sub 2}MnGa, where the softening of the TA{sub 2} phonon branch is related to Fermi-surface nesting, our results reveal that the respective anomalies are absent in Co-Ni-Ga, in the phonon dispersions as well as in the electronic structure.

  7. Modeling and Characterization of the Magnetocaloric Effect in Ni2MnGa Materials

    SciTech Connect (OSTI)

    Nicholson, Don M; Odbadrakh, Khorgolkhuu; Rios, Orlando; Hodges, Jason P; Ludtka, Gerard Michael; Porter, Wallace D; Sefat, A. S.; Rusanu, Aurelian; Evans III, Boyd Mccutchen

    2012-01-01

    Magnetic shape memory alloys have great promise as magneto-caloric effect refrigerant materials due to their combined magnetic and structural transitions. Computational and experimental research is reported on the Ni2MnGa material system. The magnetic states of this system have been explored using the Wang-Landau statistical approach in conjunction with the Locally Self-consistent Multiple-Scattering (LSMS) method to explore the magnetic states responsible for the magnet-caloric effect in this material. The effects of alloying agents on the transition temperatures of the Ni2MnGa alloy were investigated using differential scanning calorimetry (DSC) and superconducting quantum interference device (SQUID). Neutron scattering experiments were performed to observe the structural and magnetic phase transformations at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL) on alloys of Ni-Mn-Ga and Ni-Mn-Ga-Cu-Fe. Data from the observations are discussed in comparison with the computational studies.

  8. Hydrogen absorption characteristics of amorphous LaNi[sub 5. 0] films prepared by reactive sputtering

    SciTech Connect (OSTI)

    Sakaguchi, H.; Tsujimoto, T.; Adachi, Ginya (Osaka University, Suita (Japan))

    1993-01-01

    Amorphous LaNi[sub 5] thin films are expected to be one of the promising materials for use in hydrogen separation and battery electrodes, because the durability of the films is great in regard to the hydrogen absorption-desorption cycling process and the films have excellent resistance to harmful impurities in the hydrogen gas in comparison with the crystalline bulk material. An amorphous LaNi[sub 5.0] film having high hydrogen density and low hydrogen-induced stress was obtained by means of a reactive sputtering method using an Ar-H[sub 2] gas mixture. Pressure-composition isotherms show that the amount of hydrogen (H/LaNi[sub 5.0]) taken up by a formula weight of LaNi[sub 5.0] is about 1.5 times larger for the reactive sputtered film than for the conventional sputtered film prepared by using Ar gas. 18 refs., 1 fig, 1 tabs.

  9. Thermodynamic modeling and experimental validation of the Fe-Al-Ni-Cr-Mo alloy system

    SciTech Connect (OSTI)

    Teng, Zhenke; Zhang, F; Miller, Michael K; Liu, Chain T; Huang, Shenyan; Chou, Y.T.; Tien, R; Chang, Y A; Liaw, Peter K

    2012-01-01

    NiAl-type precipitate-strengthened ferritic steels have been known as potential materials for the steam turbine applications. In this study, thermodynamic descriptions of the B2-NiAl type nano-scaled precipitates and body-centered-cubic (BCC) Fe matrix phase for four alloys based on the Fe-Al-Ni-Cr-Mo system were developed as a function of the alloy composition at the aging temperature. The calculated phase structure, composition, and volume fraction were validated by the experimental investigations using synchrotron X-ray diffraction and atom probe tomography. With the ability to accurately predict the key microstructural features related to the mechanical properties in a given alloy system, the established thermodynamic model in the current study may significantly accelerate the alloy design process of the NiAl-strengthened ferritic steels.

  10. Structure and magnetic properties of Ce₃(Ni/Al/Ga)₁₁-A...

    Office of Scientific and Technical Information (OSTI)

    ...AlGa)-A new phase with the LaAl structure type Prev Next Title: Structure and magnetic properties of Ce(NiAlGa)-A new phase with the ...

  11. Microsoft Word - chapter FeNiCrMo_ver4.doc

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

    The carbon and alloy steel categories selected for the Technical Reference for Hydrogen ... Since a full range of data is not available for each steel, data for all Ni-Cr-Mo steels ...

  12. Ni-Si Alloys for the S-I Reactor-Hydrogen Production Process Interface

    SciTech Connect (OSTI)

    Joseph W. Newkirk; Richard K. Brow

    2010-01-21

    The overall goal of this project was to develop Ni-Si alloys for use in vessels to contain hot, pressurized sulfuric acid. The application was to be in the decomposition loop of the thermochemical cycle for production of hydrogen.

  13. Experimental determination of band offsets of NiO-based thin film heterojunctions

    SciTech Connect (OSTI)

    Kawade, Daisuke; Sugiyama, Mutsumi, E-mail: mutsumi@rs.noda.tus.ac.jp [Faculty of Science and Technology/Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda 278-8510 (Japan); Chichibu, Shigefusa F. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba, Sendai 9808577 (Japan)

    2014-10-28

    The energy band diagrams of NiO-based solar cell structures that use various n-type oxide semiconductors such as ZnO, Mg{sub 0.3}Zn{sub 0.7}O, Zn{sub 0.5}Sn{sub 0.5}O, In{sub 2}O{sub 3}:Sn (ITO), SnO{sub 2}, and TiO{sub 2} were evaluated by photoelectron yield spectroscopy. The valence band discontinuities were estimated to be 1.6?eV for ZnO/NiO and Mg{sub 0.3}Zn{sub 0.7}O/NiO, 1.7?eV for Zn{sub 0.5}Sn{sub 0.5}O/NiO and ITO/NiO, and 1.8?eV for SnO{sub 2}/NiO and TiO{sub 2}/NiO heterojunctions. By using the valence band discontinuity values and corresponding energy bandgaps of the layers, energy band diagrams were developed. Judging from the band diagram, an appropriate solar cell consisting of p-type NiO and n-type ZnO layers was deposited on ITO, and a slight but noticeable photovoltaic effect was obtained with an open circuit voltage (V{sub oc}) of 0.96?V, short circuit current density (J{sub sc}) of 2.2??A/cm{sup 2}, and fill factor of 0.44.

  14. Heat treatment of NiCrFe alloy 600 to optimize resistance to intergranular stress corrosion

    DOE Patents [OSTI]

    Steeves, A.F.; Bibb, A.E.

    A process of producing a NiCrFe alloy having a high resistance to stress corrosion cracking comprises heating a NiCrFe alloy to a temperature sufficient to enable the carbon present in the alloy body in the form of carbide deposits to enter into solution, rapidly cooling the alloy body, and heating the cooled body to a temperature between 1100 to 1500/sup 0/F for about 1 to 30 hours.

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

    DOE Patents [OSTI]

    Steeves, Arthur F.; Bibb, Albert E.

    1984-01-01

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

  16. An Update on Improvements to NiCE Support for RELAP-7

    SciTech Connect (OSTI)

    McCaskey, Alex; Wojtowicz, Anna; Deyton, Jordan H.; Patterson, Taylor C.; Billings, Jay Jay

    2015-01-01

    The Multiphysics Object-Oriented Simulation Environment (MOOSE) is a framework that facilitates the development of applications that rely on finite-element analysis to solve a coupled, nonlinear system of partial differential equations. RELAP-7 represents an update to the venerable RELAP-5 simulator that is built upon this framework and attempts to model the balance-of-plant concerns in a full nuclear plant. This report details the continued support and integration of RELAP-7 and the NEAMS Integrated Computational Environment (NiCE). RELAP-7 is fully supported by the NiCE due to on-going work to tightly integrate NiCE with the MOOSE framework, and subsequently the applications built upon it. NiCE development throughout the first quarter of FY15 has focused on improvements, bug fixes, and feature additions to existing MOOSE-based application support. Specifically, this report will focus on improvements to the NiCE MOOSE Model Builder, the MOOSE application job launcher, and the 3D Nuclear Plant Viewer. This report also includes a comprehensive tutorial that guides RELAP-7 users through the basic NiCE workflow: from input generation and 3D Plant modeling, to massively parallel job launch and post-simulation data visualization.

  17. Experimental determination and thermodynamic modeling of the Ni-Re binary system

    SciTech Connect (OSTI)

    Yaqoob, Khurram; Joubert, Jean-Marc

    2012-12-15

    The phase diagram of the Ni-Re binary system has been partially reinvestigated by chemical, structural and thermal characterization of the arc melted alloys. The experimental results obtained during the present investigation were combined with the literature data and a new phase diagram of the Ni-Re binary system is proposed. In comparison with the Ni-Re phase diagram proposed by Nash et al. in 1985 [1], significant differences in the homogeneity domains, freezing ranges and peritectic reaction temperature were evidenced. On the other hand, thermodynamic modeling of the studied system by using the new experimental information has also been carried out with the help of the CALPHAD method. The calculated Ni-Re phase diagram showed a good agreement with the selected experimental information. - Graphical abstract: Ni-Re phase diagram according to the present study. Highlights: Black-Right-Pointing-Pointer Re-investigation of the Ni-Re phase diagram. Black-Right-Pointing-Pointer Extended phase field of the hcp phase. Black-Right-Pointing-Pointer Different freezing ranges and peritectic reaction temperature. Black-Right-Pointing-Pointer Thermodynamic modeling of the studied system by using the CALPHAD method.

  18. Diversity, Function and Evolution of Genes Coding for Putative Ni-Containing Superoxide Dismutases

    SciTech Connect (OSTI)

    Dupont,C.; Neupane, K.; Shearer, J.; Palenik, B.

    2008-01-01

    We examined the phylogenetic distribution, functionality and evolution of the sodN gene family, which has been shown to code for a unique Ni-containing isoform of superoxide dismutase (Ni-SOD) in Streptomyces. Many of the putative sodN sequences retrieved from public domain genomic and metagenomic databases are quite divergent from structurally and functionally characterized Ni-SOD. Structural bioinformatics studies verified that the divergent members of the sodN protein family code for similar three-dimensional structures and identified evolutionarily conserved amino acid residues. Structural and biochemical studies of the N-terminus 'Ni-hook' motif coded for by the putative sodN sequences confirmed both Ni (II) ligating and superoxide dismutase activity. Both environmental and organismal genomes expanded the previously noted phylogenetic distribution of sodN, and the sequences form four well-separated clusters, with multiple subclusters. The phylogenetic distribution of sodN suggests that the gene has been acquired via horizontal gene transfer by numerous organisms of diverse phylogenetic background, including both Eukaryotes and Prokaryotes. The presence of sodN correlates with the genomic absence of the gene coding for Fe-SOD, a structurally and evolutionarily distinct isoform of SOD. Given the low levels of Fe found in the marine environment from where many sequences were attained, we suggest that the replacement of Fe-SOD with Ni-SOD may be an evolutionary adaptation to reduce iron requirements.

  19. Metallic glass alloys of Zr, Ti, Cu and Ni

    DOE Patents [OSTI]

    Lin, Xianghong; Peker, Atakan; Johnson, William L.

    1997-01-01

    At least quaternary alloys form metallic glass upon cooling below the glass transition temperature at a rate less than 10.sup.3 K/s. Such alloys comprise titanium from 19 to 41 atomic percent, an early transition metal (ETM) from 4 to 21 atomic percent and copper plus a late transition metal (LTM) from 49 to 64 atomic percent. The ETM comprises zirconium and/or hafnium. The LTM comprises cobalt and/or nickel. The composition is further constrained such that the product of the copper plus LTM times the atomic proportion of LTM relative to the copper is from 2 to 14. The atomic percentage of ETM is less than 10 when the atomic percentage of titanium is as high as 41, and may be as large as 21 when the atomic percentage of titanium is as low as 24. Furthermore, when the total of copper and LTM are low, the amount of LTM present must be further limited. Another group of glass forming alloys has the formula (ETM.sub.1-x Ti.sub.x).sub.a Cu.sub.b (Ni.sub.1-y Co.sub.y).sub.c wherein x is from 0.1 to 0.3, y.cndot.c is from 0 to 18, a is from 47 to 67, b is from 8 to 42, and c is from 4 to 37. This definition of the alloys has additional constraints on the range of copper content, b.

  20. Electrochemical Testing of Ni-Cr-Mo-Gd Alloys

    SciTech Connect (OSTI)

    T. E. Lister; R. E. Mizia; H. Tian

    2005-10-01

    The waste package site recommendation design specified a boron-containing stainless steel, Neutronit 976/978, for fabrication of the internal baskets that will be used as a corrosion-resistant neutron-absorbing material. Recent corrosion test results gave higher-than-expected corrosion rates for this material. The material callout for these components has been changed to a Ni-Cr-Mo-Gd alloy (ASTM-B 932-04, UNS N06464) that is being developed at the Idaho National Laboratory. This report discusses the results of initial corrosion testing of this material in simulated in-package environments that could contact the fuel baskets after breach of the waste package outer barrier. The corrosion test matrix was executed using the potentiodynamic and potentiostatic electrochemical test techniques. The alloy performance shows low rates of general corrosion after initial removal of a gadolinium-rich second phase that intersects the surface. The high halide-containing test solutions exhibited greater tendencies toward initiation of crevice corrosion.

  1. Magnetic viscosity in Ni/Cu compositionally-modulated alloys

    SciTech Connect (OSTI)

    Bennett, L.H.; Swartzendruber, L.J.; Ettedgui, H.; Atzmony, U.; Lashmore, D.S; Watson, R.E.; Brookhaven National Lab., Upton, NY )

    1989-01-01

    The existence of a magnetic aftereffect ( magnetic viscosity'') in Ni/Cu multilayered alloys was established using a vibrating sample magnetometer at room temperature and at 86 K. It was shown that the effect is strongly dependent on the step field, H{sub 2} (i.e., the value the field is reduced to after the magnetic moment has been aligned in high field) and exhibits a maximum relaxation rate for values of H{sub 2} around the reverse coercive field, {minus}H{sub c}. Aftereffect behavior of this type has been observed in other materials, though most often for systems composed of superparamagnetic particles, where the relaxation freezes out at low temperatures. In contrast, the relaxation in the CMA was shown to be enhanced at 86 K over its value at room temperature. New measurements over a wider temperature range show that the enhancement in this sample reaches a maximum near 120 K, but below that temperature the relaxation does freeze out. The temperature of maximum enhancement varies from sample to sample. 6 refs.

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

    SciTech Connect (OSTI)

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

    2014-06-28

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

  3. Insulating and metallic spin glass in Ni-doped KxFe2-ySe? single crystals

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

    Ryu, Hyejin; Abeykoon, Milinda; Wang, Kefeng; Lei, Hechang; Lazarevic, N.; Warren, J. B.; Bozin, E. S.; Popovic, Z. V.; Petrovic, C.

    2015-05-04

    We report electron doping effects by Ni in KxFe2-?-yNiySe? (0.06 ? y ? 1.44) single crystal alloys. A rich ground state phase diagram is observed. A small amount of Ni (~ 4%) suppressed superconductivity below 1.8 K, inducing insulating spin glass magnetic ground state for higher Ni content. With further Ni substitution, metallic resistivity is restored. For high Ni concentration in the lattice the unit cell symmetry is high symmetry I4/mmm with no phase separation whereas both I4/m + I4/mmm space groups were detected in the phase separated crystals when concentration of Ni morewith the absence of crystalline Fe vacancy order.less

  4. Insulating and metallic spin glass in Ni-doped K x Fe 2 - y Se 2 single crystals

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

    Ryu, Hyejin; Abeykoon, Milinda; Wang, Kefeng; Lei, Hechang; Lazarevic, N.; Warren, J. B.; Bozin, E. S.; Popovic, Z. V.; Petrovic, C.

    2015-05-04

    We report electron doping effects by Ni in KxFe2-δ-yNiySe₂(0.06≤y≤1.44) single-crystal alloys. A rich ground-state phase diagram is observed. A small amount of Ni (~4%) suppressed superconductivity below 1.8 K, inducing insulating spin-glass magnetic ground state for higher Ni content. With further Ni substitution, metallic resistivity is restored. For high Ni concentration in the lattice the unit cell symmetry is high symmetry I4/mmm with no phase separation whereas both I4/m+I4/mmm space groups were detected in the phase separated crystals when concentration of Ni < Fe. The absence of superconductivity coincides with the absence of crystalline Fe vacancy order.

  5. Observation of Precipitation Evolution in Fe-Ni-Mn-Ti-Al Maraging Steel using Atom Probe Tomography

    SciTech Connect (OSTI)

    Pereloma, E. V.; Stohr, R A; Miller, Michael K; Ringer, S. P.

    2009-01-01

    We describe the full decomposition sequence in an Fe-Ni-Mn-Ti-Al maraging steel during isothermal annealing at 550 C. Following significant pre-precipitation clustering reactions within the supersaturated martensitic solid solution, (Ni,Fe){sub 3}Ti and (Ni,Fe){sub 3}(Al,Mn) precipitates eventually form after isothermal aging for {approx}60 seconds. The morphology of the (Ni,Fe){sub 3}Ti particles changes gradually during aging from predominantly plate-like to rod-like, and, importantly, Mn and Al were observed to segregate to these precipitate/matrix interfaces. The (Ni,Fe){sub 3}(Al,Mn) precipitates occurred at two main locations: uniformly within the matrix and at the periphery of the (Ni,Fe){sub 3}Ti particles. We relate this latter mode of precipitation to the Mn-Al segregation.

  6. Magnetic structures of R5Ni2In4 and R 11Ni4In9 ( R = Tb and Ho): strong hierarchy in the temperature dependence of the magnetic ordering in the multiple rare-earth sublattices

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

    Ritter, C.; Provino, A.; Manfrinetti, P.; Pecharsky, V. K.; Gschneidner, K. A.; Dhar, S. K.

    2015-11-09

    The magnetic properties and magnetic structures of the R5Ni2In4 and the microfibrous R 11Ni4In9 compounds with R = Tb and Ho have been examined using magnetization, heat capacity, and neutron diffraction data. Rare earth atoms occupy three and five symmetrically inequivalent rare earth sites in R5Ni2In4 and R 11Ni4In9 compounds, respectively. As a result of the intra- and inter-magnetic sublattice interactions, the magnetic exchange interactions are different for various rare earth sites; this leads to a cascade of magnetic transitions with a strong hierarchy in the temperature dependence of the magnetic orderings.

  7. In Situ Time-Resolved Characterization of Ni-MoO2 Catalysts for the Water-Gas Shift Reaction

    SciTech Connect (OSTI)

    Wen,W.; Calderon, J.; Brito, J.; Marinkovic, N.; Hanson, J.; Rodriquez, J.

    2008-01-01

    Active catalysts for the water-gas shift (WGS, CO + H2O ? H2 + CO2) reaction were synthesized from nickel molybdates ({beta}-NiMoO4 and nH2O{center_dot}NiMoO4) as precursors, and their structural transformations were monitored using in situ time-resolved X-ray diffraction and X-ray absorption near-edge spectroscopy. In general, the nickel molybdates were not stable and underwent partial reduction in the presence of CO or CO/H2O mixtures at high temperatures. The interaction of {beta}-NiMoO4 with the WGS reactants at 500 C led to the formation of a mixture of Ni (24 nm particle size) and MoO2 (10 nm particle size). These Ni-MoO2 systems displayed good catalytic activity at 350, 400, and 500 C. At 350 and 400 C, catalytic tests revealed that the Ni-MoO2 system was much more active than isolated Ni (some activity) or isolated MoO2 (negligible activity). Thus, cooperative interactions between the admetal and oxide support were probably responsible for the high WGS activity of Ni-MoO2. In a second synthetic approach, the NiMoO4 hydrate was reduced to a mixture of metallic Ni, NiO, and amorphous molybdenum oxide by direct reaction with H2 gas at 350 C. In the first pass of the water-gas shift reaction, MoO2 appeared gradually at 500 C with a concurrent increase of the catalytic activity. For these catalysts, the particle size of Ni (4 nm) was much smaller than that of the MoO2 (13 nm). These systems were found to be much more active WGS catalysts than Cu-MoO2, which in turn is superior to commercial low-temperature Cu-ZnO catalysts.

  8. Exploring the influence of transfer channels on fusion reactions: The case of 40 Ca + 58,64 Ni

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

    Bourgin, D.; Courtin, S.; Haas, F.; Goasduff, A.; Stefanini, A. M.; Montagnoli, G.; Montanari, D.; Corradi, L.; Huiming, J.; Scarlassara, F.; et al

    2015-01-29

    Fusion cross sections have been measured in the 40Ca + 58Ni and 40Ca + 64Ni systems at beam energies ranging from Elab = 104.75 MeV to 153.5 MeV using the Laboratori Nazionali di Legnaro electrostatic deflector. Distributions of barriers have been extracted from the experimental data. Preliminary coupled channel calculations were performed and hints of effects of neutron transfers on the fusion below the barrier in the 40Ca + 64Ni are discussed.

  9. Metallic glass alloys of Zr, Ti, Cu and Ni

    DOE Patents [OSTI]

    Lin, X.; Peker, A.; Johnson, W.L.

    1997-04-08

    At least quaternary alloys form metallic glass upon cooling below the glass transition temperature at a rate less than 10{sup 3} K/s. Such alloys comprise titanium from 19 to 41 atomic percent, an early transition metal (ETM) from 4 to 21 atomic percent and copper plus a late transition metal (LTM) from 49 to 64 atomic percent. The ETM comprises zirconium and/or hafnium. The LTM comprises cobalt and/or nickel. The composition is further constrained such that the product of the copper plus LTM times the atomic proportion of LTM relative to the copper is from 2 to 14. The atomic percentage of ETM is less than 10 when the atomic percentage of titanium is as high as 41, and may be as large as 21 when the atomic percentage of titanium is as low as 24. Furthermore, when the total of copper and LTM are low, the amount of LTM present must be further limited. Another group of glass forming alloys has the formula (ETM{sub 1{minus}x}Ti{sub x}){sub a} Cu{sub b} (Ni{sub 1{minus}y}Co{sub y}){sub c} wherein x is from 0.1 to 0.3, y{center_dot}c is from 0 to 18, a is from 47 to 67, b is from 8 to 42, and c is from 4 to 37. This definition of the alloys has additional constraints on the range of copper content, b. 2 figs.

  10. Kinetic study of hydrogen evolution reaction on Ni{sub 30} Mo{sub 70}, Co{sub 30}Mo{sub 70}, Co{sub 30}Ni{sub 70} and Co{sub 10}Ni{sub 20}Mo{sub 70} alloy electrodes

    SciTech Connect (OSTI)

    Dominguez-Crespo, M.A.; Plata-Torres, M.; Torres-Huerta, A.M.; Arce-Estrada, E.M. . E-mail: earce@ipn.mx; Hallen-Lopez, J.M.

    2005-07-15

    The hydrogen evolution reaction on nanocrystalline Ni{sub 30}Mo{sub 70}, Co{sub 30}Mo{sub 70}, Co{sub 30}Ni{sub 70}, and Co{sub 10}Ni{sub 20}Mo{sub 70}, metallic powders prepared by mechanical alloying was investigated with linear polarization and ac impedance methods, in 30 wt.% KOH aqueous solution at room temperature. The formation process and structural properties of these nanocrystalline materials were characterized by X-ray diffraction and transmission electron microscopy. Alloyed powders showed the presence of two phases: an fcc solid solution and intermetallic compounds of Ni, Co and Mo. Based on polarization and ac impedance measurements, an improved electrocatalytic activity for hydrogen evolution reaction was observed in mechanically alloyed Co{sub 30}Ni{sub 70} powders, which is slightly higher than milled metallic Ni powders.

  11. Reducing the deactivation of Ni-metal during the catalytic partial oxidation of a surrogate diesel fuel mixture

    SciTech Connect (OSTI)

    Haynes, Daniel J.; Campos, Andrew; Smith, Mark W.; Berry, David A.; Shekhawat, Dushyant; Spivey, James J.

    2010-09-01

    Ni catalysts are active and selective for the conversion of hydrocarbon into synthesis gas. However, conventional supported Ni catalysts rapidly deactivate at the high temperatures required for partial oxidation of diesel fuel by sintering and metal vaporization, as well as by carbon deposition and sulfur poisoning. Thus, to reduce deactivation Ni (3 wt%) was substituted into the structures of Ba-hexaaluminate (BNHA) and La–Sr–Zr pyrochlore (LSZN), and their activity was compared to a supported Ni/Al2O3 for the catalytic partial oxidation (CPOX) of a surrogate diesel fuel. Characterization by XRD showed a single phase -alumina for the hexaaluminate, while LSZN had a pyrochlore structure with a defect SrZrO3 perovskite phase. Temperature programmed reduction experiments confirmed Ni was reducible in all catalysts. XANES results confirmed that Ni atoms were substituted into the hexaaluminate and pyrochlore structures, as spectra for each catalyst showed different coordination environments for Ni compared to a NiO standard. During CPOX activity tests (T = 900°C and WHSV= 50,000 scc/gcat/h), the LSZN pyrochlore produced stable H2 and CO yields in the presence of 5 wt% 1-methylnaphthalene and 50ppmw dibenzothiophene/n-tetradecane for 2 h, while both Ni/Al2O3 and BNHA catalysts were irreversibly deactivated by this mixture over the same time. Activity loss was strongly linked to carbon formation

  12. A Summary of Tritium In-Bed Accountability for 1500 Liter La-Ni-Al Storage Beds

    SciTech Connect (OSTI)

    Klein, J.E.

    2001-07-31

    This paper summarizes the in-bed accountability (IBA) calibration results for all the RF LaNi4.25Al0.75 tritium storage beds.

  13. Production of Ni-Cr-Ti-natural fibres composite and investigation of mechanical properties

    SciTech Connect (OSTI)

    Pesmen, G.; Erol, A.

    2015-03-30

    Intermetallic materials such as Ni{sub 2}Ti, Cr{sub 2}Ti are among advanced technology materials that have outstanding mechanical and physical properties for high temperature applications. Especially creep resistance, low density and high hardness properties stand out in such intermetallics. The microstructure, mechanical properties of (%50Ni-%48Cr-%2Ti)-%10Naturel Fibres and (%64Ni-%32Cr-%4Ti)-%10Naturel Fibres powders were investigated using specimens produced by tube furnace sintering at 1000-1200-1400C temperature. A composite consisting of ternary additions, a metallic phase, Ti,Cr and Ni have been prepared under Ar shroud and then tube furnace sintered. XRD, SEM (Scanning Electron Microscope), were investigated to characterize the properties of the specimens. Experimental results carried out for composition (%64Ni-%32Cr-%4Ti)-%10Naturel at 1400C suggest that the best properties as 112.09HV and 5,422g/cm{sup 3} density were obtained at 1400C.

  14. Electron phonon coupling in Ni-based binary alloys with application to displacement cascade modeling

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

    Samolyuk, German D.; Stocks, George Malcolm; Stoller, Roger E.

    2016-04-01

    Energy transfer between lattice atoms and electrons is an important channel of energy dissipation during displacement cascade evolution in irradiated materials. On the assumption of small atomic displacements, the intensity of this transfer is controlled by the strength of electron–phonon (el–ph) coupling. The el–ph coupling in concentrated Ni-based alloys was calculated using electronic structure results obtained within the coherent potential approximation. It was found that Ni0.5Fe0.5, Ni0.5Co0.5 and Ni0.5Pd0.5 are ordered ferromagnetically, whereas Ni0.5Cr0.5 is nonmagnetic. Since the magnetism in these alloys has a Stoner-type origin, the magnetic ordering is accompanied by a decrease of electronic density of states atmore » the Fermi level, which in turn reduces the el–ph coupling. Thus, the el–ph coupling values for all alloys are approximately 50% smaller in the magnetic state than for the same alloy in a nonmagnetic state. As the temperature increases, the calculated coupling initially increases. After passing the Curie temperature, the coupling decreases. The rate of decrease is controlled by the shape of the density of states above the Fermi level. Introducing a two-temperature model based on these parameters in 10 keV molecular dynamics cascade simulation increases defect production by 10–20% in the alloys under consideration.« less

  15. Structure and properties of Nd{sub 5}Ni{sub 6}In{sub 11}

    SciTech Connect (OSTI)

    Poettgen, R.; Hoffman, R.D.; Kremer, R.K.; Schnelle, W.

    1999-01-01

    The title compound was prepared from the elements by a reaction in an arc melting furnace and subsequent annealing at 970 K. Nd{sub 5}Ni{sub 6}In{sub 11} crystallizes with the orthorhombic Pr{sub 5}Ni{sub 6}In{sub 11}-type structure: Cmmm, a = 1455.9(3) pm, b = 1453.3(3) pm, c = 438.3(1) pm, V = 0.9274(2) nm{sup 3}, wR{sub 2} = 0.0551, 1086 F{sup 2} values, and 42 variables. The structure of Nd{sub 5}Ni{sub 6}In{sub 11} is built up from a complex three-dimensionally infinite [Ni{sub 6}In{sub 11}] polyanionic network in which the neodymium atoms occupy pentagonal and hexagonal channels. Magnetic susceptibility measurements indicate Curie-Weiss behavior above 150 K with an experimental magnetic moment of 3.60(5) {mu}{sub B}/Nd and a paramagnetic Curie temperature of {minus}18(1) K. Antiferromagnetic ordering is detected at T{sub N} = 11.4(1) K. Field- and temperature-dependent magnetization data indicate a complex magnetic phase diagram with spin reorientations into three antiferro- and one ferrimagnetic phase. The magnetic data are supported by specific heat measurements. Nd{sub 5}Ni{sub 6}In{sub 11} is a metallic conductor with a specific resistivity of 120 {mu}{Omega} cm at room temperature.

  16. Stability of Surface and Subsurface Hydrogen on and in Au/Ni Near-Surface Alloys

    SciTech Connect (OSTI)

    Celik, Fuat E.; Mavrikakis, Manos

    2015-10-01

    Periodic, self-consistent DFT-GGA (PW91) calculations were used to study the interaction of hydrogen atoms with the (111) surfaces of substitutional near-surface alloys (NSAs) of Au and Ni with different surface layer compositions and different arrangements of Au atoms in the surface layer. The effect of hydrogen adsorption on the surface and in the first and second subsurface layers of the NSAs was studied. Increasing the Au content in the surface layer weakens hydrogen binding on the surface, but strengthens subsurface binding, suggesting that the distribution of surface and subsurface hydrogen will be different than that on pure Ni(111). While the metal composition of the surface layer has an effect on the binding energy of hydrogen on NSA surfaces, the local composition of the binding site has a stronger effect. For example, fcc hollow sites consisting of three Ni atoms bind H nearly as strongly as on Ni(111), and fcc sites consisting of three Au atoms bind H nearly as weakly as on Au(111). Sites with one or two Au atoms show intermediate binding energies. The preference of hydrogen for three-fold Ni hollow sites alters the relative stabilities of different surface metal atom arrangements, and may provide a driving force for adsorbate-induced surface rearrangement.

  17. Direct Observation of Photoinduced Charge Separation in Ruthenium Complex/Ni(OH)2 Nanoparticle Hybrid

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

    Tang, Yu; Pattengale, Brian A.; Ludwig, John M.; Atifi, Abderrahman; Zinovev, Alexander V.; Dong, Bin; Kong, Qingyu; Zuo, Xiaobing; Zhang, Xiaoyi; Huang, Jier

    2015-12-17

    We report that Ni(OH)2 have emerged as important functional materials for solar fuel conversion because of their potential as cost-effective bifunctional catalysts for both hydrogen and oxygen evolution reactions. However, their roles as photocatalysts in the photoinduced charge separation (CS) reactions remain unexplored. In this paper, we investigate the CS dynamics of a newly designed hybrid catalyst by integrating a Ru complex with Ni(OH)2 nanoparticles (NPs). Using time resolved X-ray absorption spectroscopy (XTA), we directly observed the formation of the reduced Ni metal site (~60 ps), unambiguously demonstrating CS process in the hybrid through ultrafast electron transfer from Ru complexmore » to Ni(OH)2 NPs. Compared to the ultrafast CS process, the charge recombination in the hybrid is ultraslow (>>50 ns). These results not only suggest the possibility of developing Ni(OH)2 as solar fuel catalysts, but also represent the first time direct observation of efficient CS in a hybrid catalyst using XTA.« less

  18. Effect of Surface Termination on the Electonic Properties of LaNiO? Films

    SciTech Connect (OSTI)

    Kumah, Divine P.; Malashevich, Andrei; Disa, Ankit S.; Arena, Dario A.; Walker, Fred J.; Ismail-Beigi, Sohrab; Ahn, Charles H.

    2014-11-06

    The electronic and structural properties of thin LaNiO? films grown by using molecular beam epitaxy are studied as a function of the net ionic charge of the surface terminating layer. We demonstrate that electronic transport in nickelate heterostructures can be manipulated through changes in the surface termination due to a strong coupling of the surface electrostatic properties to the structural properties of the NiO bonds that govern electronic conduction. We observe experimentally and from first-principles theory an asymmetric response of the structural properties of the films to the sign of the surface charge, which results from a strong interplay between electrostatic and mechanical boundary conditions governing the system. The structural response results in ionic buckling in the near-surface NiO? planes for films terminated with negatively charged NiO? and bulklike NiO? planes for films terminated with positively charged LaO planes. The ability to modify transport properties by the deposition of a single atomic layer can be used as a guiding principle for nanoscale device fabrication.

  19. Imaging of electrical response of NiOx under controlled environment with sub-25-nm resolution

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

    Jacobs, Christopher B.; Ievlev, Anton V.; Collins, Liam F.; Muckley, Eric S.; Joshi, Pooran C.; Ivanov, Ilia N.

    2016-07-19

    The spatially resolved electrical response of rf-sputtered polycrystalline NiOx films composed of 40 nm crystallites was investigated under different relative humidity levels (RH). The topological and electrical properties (surface potential and resistance) were characterized using Kelvin probe force microscopy (KPFM) and conductive scanning probe microscopy at 0%, 50%, and 80% relative humidity with sub 25nm resolution. The surface potential of NiOx decreased by about 180 mV and resistance decreased in a nonlinear fashion by about 2 G when relative humidity was increased from 0% to 80%. The dimensionality of surface features obtained through autocorrelation analysis of topological, surface potential andmore » resistance maps increased linearly with increased relative humidity as water was adsorbed onto the film surface. Spatially resolved surface potential and resistance of the NiOx films were found to be heterogeneous, with distinct features that grew in size from about 60 nm to 175 nm between 0% and 80% RH levels, respectively. Here, we find that the changes in the heterogeneous character of the NiO films are consistent through the topological, surface potential, and resistance measurements, suggesting that the nanoscale surface potential and resistance properties converge with the mesoscale properties as water is adsorbed onto the NiOx film.« less

  20. Aging effects in palladium and LaNi sub 4. 25 Al sub 0. 75 tritides

    SciTech Connect (OSTI)

    Nobile, A.; Wermer, J.R. ); Walters, R.T. . Plasma Physics Lab.)

    1992-03-01

    Palladium and LaNi{sub 5{minus}x}Al{sub x} (x = 0.30, 0.75, 0.85), which from reversible hydrides, are used for tritium processing and storage in the Savannah River Site (SRS) tritium facilities. As part of a program to develop technology based on the use of reversible metal hydrides for tritium processing and storage, the effects of aging on the thermodynamic behavior of palladium and LaNi{sub 4.25}Al{sub 0.75} tritides are under investigation. During aging, the {sup 3}He tritium decay product remains in the tritide lattice and changes the thermodynamics of the tritium-metal tritide system. Aging effects in 755-day-aged palladium and 1423-day-aged LaNi{sub 4.25}Al{sub 0.75} tritides are reported. Changes in the thermodynamics are determined by measuring tritium desorption isotherms on aging samples. In palladium, aging deceases the desorption isotherm plateau pressure and changes the {alpha}-phase portion of the isotherm. aging-induced changes in desorption isotherms are more drastic in LaNi{sub 4.25}Al{sub 0.75}. Various processes occurring in the tritide lattice which might be responsible for the observed aging effects in palladium and LaNi{sub 4.25}Al{sub 0.75} tritides are discussed in this paper.

  1. Hybrid density functional theory description of N- and C-doping of NiO

    SciTech Connect (OSTI)

    Nolan, Michael; Long, Run; English, Niall J.; Mooney, Damian A.

    2011-06-14

    The large intrinsic bandgap of NiO hinders its potential application as a photocatalyst under visible-light irradiation. In this study, we have performed first-principles screened exchange hybrid density functional theory with the HSE06 functional calculations of N- and C-doped NiO to investigate the effect of doping on the electronic structure of NiO. C-doping at an oxygen site induces gap states due to the dopant, the positions of which suggest that the top of the valence band is made up primarily of C 2p-derived states with some Ni 3d contributions, and the lowest-energy empty state is in the middle of the gap. This leads to an effective bandgap of 1.7 eV, which is of potential interest for photocatalytic applications. N-doping induces comparatively little dopant-Ni 3d interactions, but results in similar positions of dopant-induced states, i.e., the top of the valence band is made up of dopant 2p states and the lowest unoccupied state is the empty gap state derived from the dopant, leading to bandgap narrowing. With the hybrid density functional theory (DFT) results available, we discuss issues with the DFT corrected for on-site Coulomb description of these systems.

  2. Surface roughness and interface width scaling of magnetron sputter deposited Ni/Ti multilayers

    SciTech Connect (OSTI)

    Maidul Haque, S.; Biswas, A.; Tokas, R. B.; Bhattacharyya, D.; Sahoo, N. K.; Bhattacharya, Debarati

    2013-09-14

    Using an indigenously built r.f. magnetron sputtering system, several single layer Ti and Ni films have been deposited at varying deposition conditions. All the samples have been characterized by Grazing Incidence X-ray Reflectivity (GIXR) and Atomic Force Microscopy to estimate their thickness, density, and roughness and a power law dependence of the surface roughness on the film thickness has been established. Subsequently, at optimized deposition condition of Ti and Ni, four Ni/Ti multilayers of 11-layer, 21-layer, 31-layer, and 51-layer having different bilayer thickness have been deposited. The multilayer samples have been characterized by GIXR and neutron reflectivity measurements and the experimental data have been fitted assuming an appropriate sample structure. A power law correlation between the interface width and bilayer thickness has been observed for the multilayer samples, which was explained in the light of alternate roughening/smoothening of multilayers and assuming that at the interface the growth restarts every time.

  3. Importance of Size and Distribution of Ni Nanoparticles for the Hydrodeoxygenation of Microalgae Oil

    SciTech Connect (OSTI)

    Song, Wenji; Zhao, Chen; Lercher, Johannes A.

    2013-07-22

    Improved synthetic approaches for preparing small-sized Ni nanoparticles (d=3 nm) supported on HBEA zeolite have been explored and compared with the traditional impregnation method. The formation of surface nickel silicate/aluminate involved in the two precipitation processes are inferred to lead to the stronger interaction between the metal and the support. The lower Brnsted acid concentrations of these two Ni/HBEA catalysts compared with the parent zeolite caused by the partial exchange of Brnsted acid sites by Ni2+ cations do not influence the hydrodeoxygenation rates, but alter the product selectivity. Higher initial rates and higher stability have been achieved with these optimized catalysts for the hydrodeoxygenation of stearic acid and microalgae oil. Small metal particles facilitate high initial catalytic activity in the fresh sample and size uniformity ensures high catalyst stability.

  4. Electrical properties of the amorphous interfacial layer between Al electrodes and epitaxial NiO films

    SciTech Connect (OSTI)

    Hyuck Jang, Jae; Kwon, Ji-Hwan; Kim, Miyoung; Ran Lee, Seung; Char, Kookrin

    2012-04-23

    The amorphous interfacial layer (a-IL) between Al electrode and epitaxial NiO films were studied using electron energy-loss spectroscopy (EELS) and energy-dispersive x-ray spectroscopy. Two distinct properties were found in the a-IL, i.e., a lower metallic and an upper insulating layer. EELS results revealed that the metallic Ni atoms were responsible for the conducting nature of the lower oxide amorphous layer. The resistance behavior of Al/a-IL/epi-NiO was changed from a high to a low resistance state after forming process. The resistance change could be explained by the formation of a nanocrystalline metal alloy in the insulating amorphous layer.

  5. Simulation of atomic diffusion in the Fcc NiAl system: A kinetic Monte Carlo study

    SciTech Connect (OSTI)

    Alfonso, Dominic R.; Tafen, De Nyago

    2015-04-28

    The atomic diffusion in fcc NiAl binary alloys was studied by kinetic Monte Carlo simulation. The environment dependent hopping barriers were computed using a pair interaction model whose parameters were fitted to relevant data derived from electronic structure calculations. Long time diffusivities were calculated and the effect of composition change on the tracer diffusion coefficients was analyzed. These results indicate that this variation has noticeable impact on the atomic diffusivities. A reduction in the mobility of both Ni and Al is demonstrated with increasing Al content. As a result, examination of the pair interaction between atoms was carried out for the purpose of understanding the predicted trends.

  6. Characterizations Of Precipitate Phases In a Ti-Ni-Pd Alloy

    SciTech Connect (OSTI)

    Yang, Fan; Kovarik, Libor; Phillips, Patrick J.; Noebe, Ronald D.; Mills, M. J.

    2012-06-01

    Precipitates in the Ti46Ni37.5Pd16.5 alloy were investigated by electron diffraction and high-resolution scanning transmission electron microscopy. The phase content and stability were determined at several different temperatures and times. Aging at 400 C for an hour results in a new phase, which is consumed by P-phase at longer aging time. At 450 C, the new phase appears first, and then coexists with P-phase. At 500 C, the entire alloy transformed into the new phase. At 550 C, Ti3(Ni,Pd)4 phase begins to form.

  7. Unoccupied electronic structure of Ni2MnGa ferromagnetic shape memory alloy

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

    Maniraj, M.; D׳Souza, S. W.; Rai, Abhishek; Schlagel, D. L.; Lograsso, T. A.; Iowa State Univ., Ames, IA; Chakrabarti, Aparna; Barman, S. R.

    2015-08-20

    Momentum resolved inverse photoemission spectroscopy measurements show that the dispersion of the unoccupied bands of Ni2MnGa is significant in the austenite phase. Furthermore, in the martensite phase, it is markedly reduced, which is possibly related to the structural transition to an incommensurate modulated state in the martensite phase. Finally, based on the first principle calculations of the electronic structure of Ni–Mn–Ga, we show that the modification of the spectral shape with surface composition is related to change in the hybridization between the Mn 3d and Ni 3d-like states that dominate the unoccupied conduction band.

  8. Preparation and characterization of nanodiamond cores coated with a thin Ni-Zn-P alloy film

    SciTech Connect (OSTI)

    Wang Rui; Ye Weichun; Ma Chuanli; Wang Chunming

    2008-02-15

    Nanodiamond cores coated with a thin Ni-Zn-P alloy film were prepared by an electroless deposition method under the conditions of tin chloride sensitization and palladium chloride activation. The prepared materials were analyzed by Fourier transform infrared (FTIR) spectrometry and X-ray diffraction (XRD). The nanostructure of the materials was then characterized by transmission electron microscopy (TEM). The alloy film composition was characterized by Energy Dispersive X-ray (EDX) analysis. The results indicated the approximate composition 49.84%Ni-37.29%Zn-12.88%P was obtained.

  9. Structural transformations in Mn{sub 2}NiGa due to residual stress

    SciTech Connect (OSTI)

    Singh, Sanjay; Maniraj, M.; D'Souza, S. W.; Barman, S. R.; Ranjan, R.

    2010-02-22

    Powder x-ray diffraction study of Mn{sub 2}NiGa ferromagnetic shape memory alloy shows the existence of a 7M monoclinic modulated structure at room temperature (RT). The structure of Mn{sub 2}NiGa is found to be highly dependent on residual stress. For higher stress, the structure is tetragonal at RT, and for intermediate stress it is 7M monoclinic. However, only when the stress is considerably relaxed, the structure is cubic, as is expected at RT since the martensitic transition temperature is 230 K.

  10. Modeling and Characterization of the Magnetocaloric Effect in Ni2MnGa Materials

    SciTech Connect (OSTI)

    Nicholson, Don M; Odbadrakh, Khorgolkhuu; Shassere, Benjamin; Rios, Orlando; Hodges, Jason P; Ludtka, Gerard Michael; Porter, Wallace D; Safa-Sefat, Athena; Rusanu, Aurelian; Brown, Greg; Evans III, Boyd Mccutchen

    2014-01-01

    Magnetic shape memory alloys have great promise as magneto-caloric effect refrigerant materials due to their combined magnetic and structural transitions. Computational and experimental research is reported on the Ni2MnGa material system. The magnetic states of this system are explored using the Wang-Landau statistical approach in conjunction with the Locally Self-consistent Multiple-Scattering method. The effects of alloying agents on the transition temperatures of the Ni2MnGa alloy are investigated using differential scanning calorimetry and superconducting quantum interference device. Experiments are performed at the Spallation Neutron Source at Oak Ridge National Laboratory to observe the structural and magnetic phase transformations.