National Library of Energy BETA

Sample records for ra zr hf

  1. Ternary ceramic alloys of Zr-Ce-Hf oxides

    DOE Patents [OSTI]

    Becher, P.F.; Funkenbusch, E.F.

    1990-11-20

    A ternary ceramic alloy is described which produces toughening of zirconia and zirconia composites through the stress transformation from tetragonal phase to monoclinic phase. This alloy, having the general formula Ce[sub x]Hf[sub y]Zr[sub 1[minus]x[minus]y]O[sub 2], is produced through the addition of appropriate amounts of ceria and hafnia to the zirconia. Typically, improved toughness is achieved with about 5 to about 15 mol % ceria and up to about 40 mol % hafnia. The preparation of alloys of these compositions are given together with data as to the densities, tetragonal phase content, hardness and fracture toughness. The alloys are useful in preparing zirconia bodies as well as reinforcing ceramic composites. 1 fig.

  2. Zr-Hf separation based on a molten salt/metal

    E-Print Network [OSTI]

    Langendoen, Koen

    Zr-Hf separation based on a molten salt/metal equilibrium )URP ROGIDVKLRQHG Ã?DVKEXOEV to newfangled. These involve complicated multistep batch processes. This new purification method is based on molten salt to raw zirconium and hafnium metal, so a molten metal stream can be achieved and tin chloride salts

  3. Ternary ceramic alloys of ZR-CE-HF oxides

    DOE Patents [OSTI]

    Becher, Paul F. (Oak Ridge, TN); Funkenbusch, Eric F. (White Bear Lake, MN)

    1990-01-01

    A ternary ceramic alloy which produces toughening of zirconia and zirconia composites through the stress transformation from tetragonal phase to monoclinic phase. This alloy, having the general formula Ce.sub.x Hf.sub.y Zn.sub.1-x-y O.sub.2, is produced through the addition of appropriate amounts of ceria and hafnia to the zirconia. Typically, improved toughness is achieved with about 5 to about 15 mol % ceria and up to about 40 mol % hafnia. The preparation of alloys of these compositions are given together with data as to the densities, tetragonal phase content, hardness and fracture toughness. The alloys are useful in preparing zirconia bodies as well as reinforcing ceramic composites.

  4. Effects of ZrO{sub 2} doping on HfO{sub 2} resistive switching memory characteristics

    SciTech Connect (OSTI)

    Ryu, Seung Wook; Kwac, Jungsuk; Nishi, Yoshio [Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States); Cho, Seongjae, E-mail: felixcho@gachon.ac.kr [Department of Electronic Engineering and New Technology Component and Material Research Center (NCMRC), Gachon University, Seongnam-si, Gyeonggi-do 461-741 (Korea, Republic of); Park, Joonsuk [Department of Materials Science and Engineering, Stanford University, Stanford, California 94305 (United States); Kim, Hyeong Joon [Department of Materials Science and Engineering and Inter-university Semiconductor Research Center (ISRC), Seoul National University, Seoul 151-744 (Korea, Republic of)

    2014-08-18

    A resistive switching (RS) random access memory device with ZrO{sub 2}-doped HfO{sub 2} exhibits better RS performance than that with pure HfO{sub 2}. In particular, I{sub res}, V{sub res}, and V{sub set} are reduced by approximately 58%, 38%, and 39%, respectively, when HfO{sub 2} is doped with ZrO{sub 2} (9 at.?%). In addition, the ZrO{sub 2} doping in HfO{sub 2} makes the distribution of most parameters steeper. Transmission electron microscopy (TEM) analysis reveals that the deposited zirconium-doped hafnium oxide (HZO) (9 at.?%) is polycrystalline. Elemental mapping results by scanning TEM–energy dispersive spectroscopy also prove that ZrO{sub 2} is uniformly distributed in the HZO (9 at.?%) film. The possible mechanism for the improvement in the RS characteristics is also suggested on the basis of the X-ray photoelectron spectroscopy results and filamentary RS mechanism. These results suggest that the ZrO{sub 2} doping into HfO{sub 2} likely not only will reduce power consumption but also will improve cyclic endurance by controlling the nonstoichiometric phase.

  5. Mechanistic investigation of vinylic carbonfluorine bond activation of perfluorinated cycloalkenes using Cp*2ZrH2 and Cp*2ZrHF

    E-Print Network [OSTI]

    Jones, William D.

    using Cp*2ZrH2 and Cp*2ZrHF Bradley M. Kraft a , Eric Clot b , Odile Eisenstein b , William W behaves similarly [4]. In contrast, Cp*Rh(PMe3)H2 reacts with C6F6 by way of an SNAr2 attack by its conjugate base to give Cp*Rh(PMe3)(C6F5)H and fluoride ion, resulting in an autocatalytic reaction [5]. Cp

  6. Continuous production of granular or powder Ti, Zr and Hf or their alloy products

    DOE Patents [OSTI]

    White, Jack C. (Albany, OR); Oden, Laurance L. (Albany, OR)

    1993-01-01

    A continuous process for producing a granular metal selected from the group consisting of Ti, Zr or Hf under conditions that provide orderly growth of the metal free of halide inclusions comprising: a) dissolving a reducing metal selected from the group consisting of Na, Mg, Li or K in their respective halide salts to produce a reducing molten salt stream; b) preparing a second molten salt stream containing the halide salt of Ti, Zr or Hf; c) mixing and reacting the two molten streams of steps a) and b) in a continuous stirred tank reactor; d) wherein steps a) through c) are conducted at a temperature range of from about 800.degree. C. to about 1100.degree. C. so that a weight percent of equilibrium solubility of the reducing metal in its respective halide salt varies from about 1.6 weight percent at about 900.degree. C. to about 14.4 weight percent at about 1062.degree. C.; and wherein a range of concentration of the halide salt of Ti, Zn or Hf in molten halides of Na, Mg, Li or K is from about 1 to about 5 times the concentration of Na, Mg, Li or K; e) placing the reacted molten stream from step c) in a solid-liquid separator to recover an impure granular metal product by decantation, centrifugation, or filtration; and f) removing residual halide salt impurity by vacuum evaporator or inert gas sweep at temperatures from about 850.degree. C. to 1000.degree. C. or cooling the impure granular metal product to ambient temperature and water leaching off the residual metal halide salt.

  7. Microstructural Characterization and Shape Memory Response of Ni-Rich NiTiHf and NiTiZr High Temperature Shape Memory Alloys 

    E-Print Network [OSTI]

    Evirgen, Alper

    2014-08-14

    NiTiHf and NiTiZr high temperature shape memory alloys (HTSMAs) have drawn a great deal of attention as cheaper alternatives to Pt, Pd and Au alloyed NiTi-based HTSMAs while NiTiZr alloys also providing at least 20% weight reduction then its Ni...

  8. Hole Trapping at Surfaces of m?ZrO2 and m?HfO2 Nanocrystals

    SciTech Connect (OSTI)

    Wolf, Matthew J.; Mckenna, Keith P.; Shlyuger, Alexander L.

    2012-12-03

    We investigate hole trapping at the most prevalent facets of monoclinic zirconia (m-ZrO2) and hafnia (m-HfO2) nanocrystals using first-principles methods. The localization of holes at surface oxygen ions is more favorable than in the bulk crystal by up to ?1 eV. This is caused mainly by the reduction of the absolute value of the electrostatic potential at the surface ions with respect to the bulk and by the significant surface distortion caused by the hole localization. The mobility of holes at surfaces is much lower than that found in the bulk and is fairly isotropic. Unlike in cubic oxides, such as MgO and CaO, we do not find a significant driving force for preferential trapping of holes at steps on the m-ZrO2 surface. These fundamental results are relevant to mechanisms of water oxidation, photocatalysis, contact charging, and photodesorption.

  9. Electron-stimulated desorption from polished and vacuum fired 316LN stainless steel coated with Ti-Zr-Hf-V

    SciTech Connect (OSTI)

    Malyshev, Oleg B. Valizadeh, Reza; Hogan, Benjamin T.; Hannah, Adrian N.

    2014-11-01

    In this study, two identical 316LN stainless steel tubular samples, which had previously been polished and vacuum-fired and then used for the electron-stimulated desorption (ESD) experiments, were coated with Ti-Zr-Hf-V with different morphologies: columnar and dense. ESD measurement results after nonevaporable getter (NEG) activation to 150, 180, 250, and 350?°C indicated that the values for the ESD yields are significantly (2–20 times) lower than the data from our previous study with similar coatings on nonvacuum-fired samples. Based on these results, the lowest pressure and best long-term performance in particle accelerators will be achieved with a vacuum-fired vacuum chamber coated with dense Ti-Zr-Hf-V coating activated at 180?°C. This is likely due to the following facts: after NEG activation, the hydrogen concentration inside the NEG was lower than in the bulk stainless steel substrate; the NEG coating created a barrier for gas diffusion from the sample bulk to vacuum; the dense NEG coating performed better as a barrier than the columnar NEG coating.

  10. Density functional theory study of first-layer adsorption of ZrO2 and HfO2 on Ge(100)

    E-Print Network [OSTI]

    Kummel, Andrew C.

    in this manuscript), usually grown by atomic layer deposition (ALD). These oxides, under normal Ge process- ingDensity functional theory study of first-layer adsorption of ZrO2 and HfO2 on Ge(100) T.J. Grassman

  11. 13.21 Geochemistry of the Rare-Earth Element, Nb, Ta, Hf, and Zr Deposits RL Linnen, University of Western Ontario, London, ON, Canada

    E-Print Network [OSTI]

    Chakhmouradian, Anton

    13.21 Geochemistry of the Rare-Earth Element, Nb, Ta, Hf, and Zr Deposits RL Linnen, University of rare metals in natural fluids 551 13.21.2.2.2 Aqueous complexation and mineral solubility 552 13 Acknowledgments 564 References 564 13.21.1 Introduction Rare-element mineral deposits, also called rare-metal

  12. Hydrolysis of ZrCl4 and HfCl4: The Initial Steps in the High-Temperature Oxidation of Metal Chlorides to Produce ZrO2 and HfO2

    SciTech Connect (OSTI)

    Fang, Zongtang; Dixon, David A.

    2013-03-08

    The gas-phase hydrolysis of MCl4 (M = Zr, Hf) to produce the initial particles on the way to zirconia and hafnia nanoparticles has been studied with electronic structure theory. The potential energy surfaces, the themochemistry of the reaction species, and the reaction paths for the initial steps of MCl4 reacting with H2O have been calculated. The hydrolysis of MCl4 at higher temperatures begins with the formation of oxychlorohydroxides followed by the elimination of HCl instead of the direct production of MOCl2 and HCl or MO2 and HCl due to the substantial endothermicities associated with the formation of gas-phase MO2. The structural properties and heats of formation of the reactants and products are consistent with the available experimental results. A number of metal oxychlorides (oxychlorohydroxides) intermediate clusters have been studied to assess their role in the production of MO2 nanoparticles. The calculated clustering reaction energies of those intermediates are highly exothermic, so they could be readily formed in the hydrolysis process. These intermediate clusters can be formed exothermically from metal oxychlorohydroxides by the elimination of one HCl or H2O molecule. Our calculations show that the mechanisms leading to the formation of MO2 nanoparticles are complicated and are accompanied by the potential production of a wide range of intermediates, as found for the production of TiO2 particles from the high-temperature oxidation of TiCl4.

  13. Manipulation of electronic and magnetic properties of M{sub 2}C (M = Hf, Nb, Sc, Ta, Ti, V, Zr) monolayer by applying mechanical strains

    SciTech Connect (OSTI)

    Zhao, Shijun; Kang, Wei; Xue, Jianming

    2014-03-31

    Tuning the electronic and magnetic properties of a material through strain engineering is an effective strategy to enhance the performance of electronic and spintronic devices. In this paper, first-principles calculations based on density functional theory are carried out to investigate the electronic and magnetic properties of M{sub 2}C(M?=?Hf, Nb, Sc, Ta, Ti, V, Zr, known as MXenes) subjected to biaxial symmetric mechanical strains. At the strain-free state, all these MXenes exhibit no spontaneous magnetism except for Ti{sub 2}C and Zr{sub 2}C which show a magnetic moment of 1.92 and 1.25??{sub B}/unit, respectively. As the tensile strain increases, the magnetic moments of MXenes are greatly enhanced and a transition from nonmagnetism to ferromagnetism is observed for those nonmagnetic MXenes at zero strains. The most distinct transition is found in Hf{sub 2}C, in which the magnetic moment is elevated to 1.5??{sub B}/unit at a strain of 1.80%. We further show that the magnetic properties of Hf{sub 2}C are attributed to the band shift mainly composed of Hf(5d) states.

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

    SciTech Connect (OSTI)

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

    2012-01-01

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

  15. Determining Relative f and d Orbital Contributions to M?Cl Covalency in MCl62– (M = Ti, Zr, Hf, U) and UOCl5 Using Cl K-Edge X-ray Absorption Spectroscopy and Time-Dependent Density Functional Theory

    SciTech Connect (OSTI)

    Minasian, Stefan G.; Keith, Jason M.; Batista, Enrique R.; Boland, Kevin S.; Clark, David L.; Conradson, Steven D.; Kozimor, Stosh A.; Martin, Richard L.; Schwarz, Daniel E.; Shuh, David K.; Wagner, Gregory L.; Wilkerson, Marianne P.; Wolfsberg, Laura E.; Yang, Ping

    2012-03-09

    Chlorine K-edge X-ray absorption spectroscopy (XAS) and ground-state and time-dependent hybrid density functional theory (DFT) were used to probe electronic structure for O{sub h}-MCl{sub 6}{sup 2-}(M = Ti, Zr, Hf, U) and C{sub 4v}-UOCl{sub 5}{sup -}, and to determine the relative contributions of valence 3d, 4d, 5d, 6d, and 5f orbitals in M-Cl bonding. Spectral interpretations were guided by time-dependent DFT calculated transition energies and oscillator strengths, which agree well with the experimental XAS spectra. The data provide new spectroscopic evidence for the involvement of both 5f and 6d orbitals in actinide-ligand bonding in UCl{sub 6}{sup 2-}. For the MCl{sub 6}{sup 2-}, where transitions into d orbitals of t{sub 2g} symmetry are spectroscopically resolved for all four complexes, the experimentally determined Cl 3p character per M-Cl bond increases from 8.3(4)% (TiCl{sub 6}{sup 2-}) to 10.3(5)% (ZrCl{sub 6}{sup 2-}), 12(1)% (HfCl{sub 6}{sup 2-}), and 26 18(1)% (UCl{sub 6}{sup 2-}). Chlorine K-edge XAS spectra of UOCl{sub 5}{sup -} provide additional insights into the transition assignments by 27 lowering the symmetry to C{sub 4v}, where five pre-edge transitions into both 5f and 6d orbitals are observed. For UCl{sub 6}{sup 2-}, the XAS data 28 suggest that orbital mixing associated with the U 5f orbitals is considerably lower than that of the U 6d orbitals. For both UCl{sub 6}{sup 2-}29 and UOCl{sub 5}{sup -}, the ground-state DFT calculations predict a larger 5f contribution to bonding than is determined experimentally. 30 These findings are discussed in the context of conventional theories of covalent bonding for d- and f-block metal complexes.

  16. Elastic properties of perovskite ATiO{sub 3} (A?=?Be, Mg, Ca, Sr, and Ba) and PbBO{sub 3} (B?=?Ti, Zr, and Hf): First principles calculations

    SciTech Connect (OSTI)

    Pandech, Narasak; Limpijumnong, Sukit; Sarasamak, Kanoknan

    2015-05-07

    The mechanical properties of perovskite oxides depend on two metal oxide lattices that are intercalated. This provides an opportunity for separate tuning of hardness, Poisson's ratio (transverse expansion in response to the compression), and shear strength. The elastic constants of series of perovskite oxides were studied by first principles approach. Both A-site and B-site cations were systematically varied in order to see their effects on the elastic parameters. To study the effects of A-site cations, we studied the elastic properties of perovskite ATiO{sub 3} for A being Be, Mg, Ca, Sr, or Ba, one at a time. Similarly, for B-site cations, we studied the elastic properties of PbBO{sub 3} for B being Ti, Zr, or Hf, one at a time. The density functional first principles calculations with local density approximation (LDA) and generalized gradient approximation (GGA) were employed. It is found that the maximum C{sub 11} elastic constant is achieved when the atomic size of the cations at A-site and B-site are comparable. We also found that C{sub 12} elastic constant is sensitive to B-site cations while C{sub 44} elastic constant is more sensitive to A-site cations. Details and explanations for such dependencies are discussed.

  17. Mechanism of Vinylic and Allylic Carbon-Fluorine Bond Activation of Non-Perfluorinated Olefins Using Cp*2ZrH2

    E-Print Network [OSTI]

    Jones, William D.

    Using Cp*2ZrH2 Bradley M. Kraft and William D. Jones* Contribution from the Department of Chemistry, UniVersity of Rochester, Rochester, New York 14627 Received November 16, 2001 Abstract: Cp*2ZrH2 (1) (CpH10) to afford Cp*2ZrHF (2) and hydrodefluorinated products. Experimental evidence suggests

  18. Characterizing HfXZr1-XO2 by EXAFS: Relationship Between Bulk and Surface Composition, and Impact on Catalytic Selectivity for Alcohol Conversion

    SciTech Connect (OSTI)

    Jacobs, G.; Milling, M; Ji, Y; Patterson, P; Sparks, D; Davis, B

    2009-01-01

    A series of mixed Hf{sub X}Zr{sub 1-X}O{sub 2} oxide catalysts was prepared according to a recipe that yields the monoclinic structure. The samples were examined by EXAFS spectroscopy at the Zr K and Hf L{sub III} edges. A fitting model was used that simultaneously fits data from both edges, and makes use of an interdependent mixing parameter X mix to take into account substitution of the complementary atom in the nearest metal-metal shell. For XPS analysis, Scofield factors were applied to estimate the relative atomic surface concentrations of Zr and Hf. EXAFS results suggested that a solid bulk solution was formed over a wide range of X for Hf{sub X}Zr{sub 1-X}O{sub 2} binary oxides, and that the relative ratio was retained in the surface shell (i.e., including some subsurface layers by XPS) and the surface (e.g., by ISS). The increase in selectivity for the 1-alkene from dehydration of alcohols at high Zr content does not correlate smoothly with the tuned relative atomic concentration of Hf to Zr. The step change at high Zr content appears to be due to other indirect factors (e.g., surface defects, oxygen vacancies).

  19. from Sun RA * DEC * from Sun RA * DEC *

    E-Print Network [OSTI]

    Radial Distance 1way Light Time Velocity WRT Sun Distance from Sun Distance from Sun RA * DEC * Radial Distance 1way Light Time Velocity WRT Sun Distance from Sun Distance from Sun RA * DEC * AU hh

  20. Co.ra

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield Municipal Gas &SCE-SessionsSouth DakotaRobbins and Myers Co -VANaval ,, *' ;x-L* d! CTy,: y; ,Co.ra

  1. Decay Studies of the New Isotopes Hf-162,hf-163 

    E-Print Network [OSTI]

    Schrewe, U. J.; Hagberg, E.; Schmeing, H.; Hardy, John C.; Koslowsky, V. T.; Sharma, KS; Clifford, E. T. H.

    1982-01-01

    ) considering interaction between a hydraulic fracture (HF) and a pre-existing NF, has been investigated comprehensively using a two dimensional Displacement Discontinuity Method (DDM) Model in this thesis. The rock is first considered as an elastic impermeable...

  2. RA

    National Nuclear Security Administration (NNSA)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield Municipal GasAdministration Medal01 Sandia4) August 20123/%2A en NNSA sitesInformation/%2A en9/%2A

  3. eRA Training Team1 Terminations

    E-Print Network [OSTI]

    Baker, Chris I.

    eRA Training Team1 xTrain Terminations Electronic Research Administration Sponsored by: The National Institutions of Health, Office of Extramural Research April 2010 #12;eRA Training Team2 xTrain General Information xTrain Overview The following section provides general information on the xTrain

  4. eRA Training Team1 Terminations

    E-Print Network [OSTI]

    Baker, Chris I.

    eRA Training Team1 xTrain Terminations Electronic Research Administration Sponsored by: The National Institutes of Health, Office of Extramural Research March 2012 #12;eRA Training Team2 xTrain General Information xTrain Overview The following section provides general information on the xTrain

  5. Collisional quenching of highly rotationally excited HF

    E-Print Network [OSTI]

    Yang, Benhui; Forrey, R C; Stancil, P C; Balakrishnan, N

    2015-01-01

    Collisional excitation rate coefficients play an important role in the dynamics of energy transfer in the interstellar medium. In particular, accurate rotational excitation rates are needed to interpret microwave and infrared observations of the interstellar gas for nonlocal thermodynamic equilibrium line formation. Theoretical cross sections and rate coefficients for collisional deexcitation of rotationally excited HF in the vibrational ground state are reported. The quantum-mechanical close-coupling approach implemented in the nonreactive scattering code MOLSCAT was applied in the cross section and rate coefficient calculations on an accurate 2D HF-He potential energy surface. Estimates of rate coefficients for H and H$_2$ colliders were obtained from the HF-He collisional data with a reduced-potential scaling approach. The calculation of state-to-state rotational quenching cross sections for HF due to He with initial rotational levels up to $j=20$ were performed for kinetic energies from 10$^{-5}$ to 15000...

  6. Metal-Organic Frameworks Based on Previously Unknown Zr8/Hf Cubic

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory ofDid you notHeatMaRIEdioxide capture | Center for Gas SeparationsRelevant

  7. Solid-State Coexistance of (Zr12) and (Zr6) Zirconium Oxocarboxylate Clusters

    SciTech Connect (OSTI)

    Malaestean, Lurie [RWTH Aachen University; Alici, Meliha Kutluca [RWTH Aachen University; Besson, Claire [RWTH Aachen University; Ellern, Arkady [Ames Laboratory; Kogerler, Paul [RWTH Aachen University

    2013-10-30

    Ligand metathesis, Co(II) coordination, and partial condensation reactions of an archetypal {Zr6} zirconium oxocarboxylate cluster result in the first example of the coexistence of the distinct zirconium oxide frameworks {Zr6O8} and {Zr12O22}. Even minor modifications to the reaction conditions push this apparent equilibrium towards the {Zr6O8}-based product.

  8. Solid-state coexistence of {Zr12} and {Zr6} zirconium oxocarboxylate clusters

    SciTech Connect (OSTI)

    Malaestean, Iurie L. [RWTH Aachen University; Alici, Meliha Kutluca [RWTH Aachen University; Besson, Claire [RWTH Aachen University; Ellern, Arkady [Ames Laboratory; Kogerler, Paul [RWTH Aachen University

    2013-10-30

    Ligand metathesis, Co(II) coordination, and partial condensation reactions of an archetypal {Zr6} zirconium oxocarboxylate cluster result in the first example of the coexistence of the distinct zirconium oxide frameworks {Zr6O8} and {Zr12O22}. Even minor modifications to the reaction conditions push this apparent equilibrium towards the {Zr6O8}-based product.

  9. Transverse spin freezing in Ruthenium-doped a Fe 90 Zr 10 Physics Department and Centre for the Physics of Materials, McGill University, 3600 University Street, Montreal, Quebec

    E-Print Network [OSTI]

    Ryan, Dominic

    Transverse spin freezing in Ruthenium-doped a Fe 90 Zr 10 D.H. Ryan Physics Department and Centre , followed by transverse spin freezing at Txy . Comparison with earlier Mossbauer data shows that the break in B hf (T) is indeed due to transverse spin freezing, and that both Mossbauer spectroscopy and #22;SR

  10. Acidizing of Sandstone Reservoirs Using HF and Organic Acids 

    E-Print Network [OSTI]

    Yang, Fei

    2012-10-19

    Mud acid, which is composed of HCl and HF, is commonly used to remove the formation damage in sandstone reservoirs. However, many problems are associated with HCl, especially at high temperatures. Formic-HF acids have served as an alternative...

  11. WAVE-DRIVEN SURFACE FROM HF RADAR

    E-Print Network [OSTI]

    Miami, University of

    FEATURE INTERNAL CURRENTS WAVE-DRIVEN SURFACE FROM HF RADAR By Lynn K. Shay Observations from recent experiments · . . have revealed internal wave signatures. SURFACE CURRENTobservations from high oscillations are within the inter- nal wave continuum from the buoyancy to the in- ertial frequencies

  12. Numerical prediction of the thermodynamic properties of ternary Al-Ni-Hf alloys

    SciTech Connect (OSTI)

    Romanowska, Jolanta; Kotowski, S?awomir; Zagula-Yavorska, Maryana

    2014-10-06

    Thermodynamic properties of ternary Al-Hf-Ni system, such as {sup ex}G, ?{sub Al}, ?{sub Ni} and ?{sub Zr} at 1373K were predicted on the basis of thermodynamic properties of binary systems included in the investigated ternary system. The idea of predicting {sup ex}G values was regarded as the calculation of excess Gibbs energy values inside a certain area (a Gibbs triangle) unless all boundary conditions, that is values of {sup ex}G on all legs of the triangle are known. {sup ex}G and L{sub ijk} ternary interaction parameters in the Muggianu extension of the Redlich-Kister formalism are calculated numerically using Wolfram Mathematica 9 software.

  13. Wind turbine impacts on HF radar ocean surface measurements in

    E-Print Network [OSTI]

    Wyatt, Lucy

    Wind turbine impacts on HF radar ocean surface measurements in Liverpool Bay Alice Robinson School. The characterisation of the wind turbine interference is assessed and the radar cross section estimated. The modulation with wind turbine interference in a HF radar footprint are made. #12;Contents Contents iv List of Tables vii

  14. HYDROGEN FLUORIDE Hydrogen Fluoride (HF) is an extremely

    E-Print Network [OSTI]

    Lance, Veronica P.

    HYDROGEN FLUORIDE Hydrogen Fluoride (HF) is an extremely corrosive clear and colorless liquid BE PROVIDED TO INDIVIDUALS WITH EXPOSURE TO HYDROGEN FLOURIDE www.ehs.columbia.edu/HFPolicy.html HF USE. Because hydrogen fluoride can penetrate natural rubber gloves you must use only neoprene or nitrile gloves

  15. Enthalpy of mixing of liquid Ni-Zr and Cu-Ni-Zr alloys

    SciTech Connect (OSTI)

    Witusiewicz, V.T.; Sommer, F.

    2000-04-01

    Since the Al-Cu-Ni-Zr system is a basis for the production of bulk amorphous materials by rapid solidification techniques from the liquid state, it is of great scientific interest to determine the partial and the integral thermodynamic functions of liquid and undercooled liquid alloys. Such data, as was pointed out previously, are important in order to understand their extremely good glass-forming ability in multicomponent metallic systems as well as for processing improvements. In order to measure the thermodynamic properties of the Al-Cu-Ni-Zr quaternary, it is necessary to have reliable thermochemical data for its constituent canaries and ternaries first. In a series of articles, the authors have reported in detail the thermodynamic properties of liquid Al-Cu, Al-Ni, Cu-Ni, Cu-Zr, Al-Zr, Al-Cu-Ni, and Al-Cu-Zr alloys. This article deals with the direct calorimetric measurements of the partial and the integral enthalpies of mixing of liquid Ni-Zr and Cu-Ni-Zr alloys and the heat capacity of liquid Ni{sub 26}Zr{sub 74}. In a subsequent article, the authors will present similar data for the liquid ternary Al-Ni-Zr and for the liquid quaternary Al-Cu-Ni-Zr alloys.

  16. On the RA research reactor fuel management problems

    SciTech Connect (OSTI)

    Matausek, M.V.; Marinkovic, N.

    1997-12-01

    After 25 yr of operation, the Soviet-origin 6.5-MW heavy water RA research reactor was shut down in 1984. Basic facts about RA reactor operation, aging, reconstruction, and spent-fuel disposal have been presented and discussed in earlier papers. The following paragraphs present recent activities and results related to important fuel management problems.

  17. HfB2 and HfBN hard coatings by chemical vapor deposition S. Jayaraman a,c

    E-Print Network [OSTI]

    Girolami, Gregory S.

    are popular materials for hard and environmental coat- ings [1­16]. Applications include cutting tools, wearHfB2 and Hf­B­N hard coatings by chemical vapor deposition S. Jayaraman a,c , J.E. Gerbi a,c , Y rights reserved. Keywords: Hafnium diboride; Hafnium borohydride; CVD; Hard coating; Nanoindentation

  18. First-principles phase diagram calculations for the HfCTiC, ZrCTiC, and HfCZrC solid O. Adjaoud,1,*,

    E-Print Network [OSTI]

    Steinle-Neumann, Gerd

    -wall coatings for fusion reactors, protective coatings for cutting tools,2 and low-friction coatings

  19. Synthesis and characterization of lanthanum phosphate nanoparticles as carriers for 223Ra and 225Ra for targeted alpha therapy

    SciTech Connect (OSTI)

    Rojas Marin, Jessika V; Woodward, Jonathan; Chen, Nan; Rondinone, Adam Justin; Castano, Carlos H; Mirzadeh, Saed

    2015-01-01

    Introduction. Targeted alpha therapy (TAT) has the potential for killing specific tumor cells with minimum collateral damage to surrounding healthy tissue. Radionuclides such as 223Ra, 225Ra, and 225Ac are of special interest for radiotherapeutic applications as they emit multiple -particles during their decay. Utilizing appropriate carriers capable of retaining both the parent radioisotope as well as daughter products is important for the effective delivery of the radioisotope to the tumor site while mitigating global in vivo radiotoxicity. Methods. In this work, core and core+2 shells (NPs with 2 additional layers of cold LaPO4 deposited on the core surfaces) LaPO4 nanoparticles (NPs) were synthesized containing either 223Ra or 225Ra/225Ac and the retention of the parents and daughters within the NPs in vitro was investigated. Results. The NPs crystallized in rhabdophane phase with mean diameters of 3.4 and 6.3 nm for core and core+2 shells, respectively. The core LaPO 4 NPs retained up to 88% of 223Ra over 35 days. However, in the core+2 shell NPs, the retention of 223Ra and its daughter, 211Pb, was improved to > 99.9% over 27 days. Additionally, the retention of 225Ra/225Ac parents was > 99.98% and ~80% for the 221Fr and 213Bi daughters over 35 days for the core+2 shell NPs. Conclusions. These results suggest that LaPO4 NPs are potentially effective carriers of radium isotopes.

  20. Rapid determination of 226Ra in emergency urine samples

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

    Maxwell, Sherrod L.; Culligan, Brian K.; Hutchison, Jay B.; Utsey, Robin C.; McAlister, Daniel R.

    2014-02-27

    A new method has been developed at the Savannah River National Laboratory (SRNL) that can be used for the rapid determination of 226Ra in emergency urine samples following a radiological incident. If a radiological dispersive device event or a nuclear accident occurs, there will be an urgent need for rapid analyses of radionuclides in urine samples to ensure the safety of the public. Large numbers of urine samples will have to be analyzed very quickly. This new SRNL method was applied to 100 mL urine aliquots, however this method can be applied to smaller or larger sample aliquots as needed.more »The method was optimized for rapid turnaround times; urine samples may be prepared for counting in 226Ra from the urine sample matrix, followed by removal of calcium by cation exchange separation. A stacked elution method using DGA Resin was used to purify the 226Ra during the cation exchange elution step. This approach combines the cation resin elution step with the simultaneous purification of 226Ra with DGA Resin, saving time. 133Ba was used instead of 225Ra as tracer to allow immediate counting; however, 225Ra can still be used as an option. The rapid purification of 226Ra to remove interferences using DGA Resin was compared with a slightly longer Ln Resin approach. A final barium sulfate micro-precipitation step was used with isopropanol present to reduce solubility; producing alpha spectrometry sources with peaks typically 90 %), and removes interferences effectively. The sample preparation method can also be adapted to ICP-MS measurement of 226Ra, with rapid removal of isobaric interferences.« less

  1. Thermoelectric Transport in a ZrN/ScN Superlattice

    E-Print Network [OSTI]

    2009-01-01

    at Springerlink.com Thermoelectric Transport in a ZrN/ScNthe potential for a high thermoelectric ?gure of merit. Theexperimental studies of the thermoelectric transport in ZrN/

  2. Compression mode resonances in Zr-90 

    E-Print Network [OSTI]

    Youngblood, David H.; Lui, YW; John, B.; Tokimoto, Y.; Clark, HL; Chen, X.

    2004-01-01

    The giant resonance region from 10 MeV < E-x < 55 MeV in Zr-90 has been studied with inelastic scattering of 240 MeV alpha particles at small angles including 0degrees. The isoscalar monopole resonance was found to contain 100 +/- 12% of the E0...

  3. Valence electronenergy-lossspectroscopystudyofZrSiO4 and ZrO2

    SciTech Connect (OSTI)

    Spence, John; Jiang, Nan

    2013-07-01

    ZrSiO4 (zircon) and m-ZrO2 (zirconia) are fundamental and industrially important materials.This work reports the detailed valence electron energy-loss spectroscopy (VEELS) studies of these compounds. The dielectric response functions, as well as single-electron interband transition spectra,are derived from VEELS data for both ZrSiO4 and m-ZrO2, in the rang e5–50 eV using the Kramers–Kronig analysis method. Our interpretation of the interband transitions is given with the aid of ab initio calculations of density of states. The bandgap energies for both materials are also measured using VEELS.The surface and bulk plasmons are identified: the surface plasmon peaks locate at around 12 eV,and two bulk plasmon peaks are ~15–16 eV and ~25–27 eV,respectively.Although similarities in the VEELS exist between ZrSiO4 and m-ZrO2, two majo rdifferences are als onoticed and explained in terms of composition and structure differences.

  4. High-power ELF radiation generated by modulated HF heating of the ionosphere can cause Earthquakes, Cyclones and localized heating

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    transmitter radiates a strong beam of high- frequency (HF) waves modulated at ELF. This HF heating modulates-frequency (HF) radiation in the megahertz range [7]. This heating modulates the electron's temperature in the D

  5. HF Radio in the International Information Infrastructure Eric E. Johnson

    E-Print Network [OSTI]

    Johnson, Eric E.

    HF Radio in the International Information Infrastructure Eric E. Johnson New Mexico State into the rapidly expanding global Internet. 1. INTRODUCTION Advancements in the international information network and the Internet (the latter relying largely upon the services of the former). However, some

  6. Interactions Among Ionospheric Propagation, HF Modems, and Data Protocols

    E-Print Network [OSTI]

    Johnson, Eric E.

    Mexico State University Abstract The well-known challenges in using the ionospheric skywave channel to Internet-style network- and ap- plication-layer protocols, which have been designed with reliable, high that will form the basis of reliable Internet operation via next-generation HF radio networks. Introduction

  7. ARQ PROTOCOL FEATURES FOR HF RADIO LINKS Eric E. Johnson

    E-Print Network [OSTI]

    Johnson, Eric E.

    ARQ PROTOCOL FEATURES FOR HF RADIO LINKS Eric E. Johnson New Mexico State University ABSTRACT The explosion of interest in using Internet-style applica- tions over wireless links prompts investigation links with Internet-style workloads. The investigation is focused on high-frequency radio links

  8. MARS15 DPA Update RaDIATE Meeting

    E-Print Network [OSTI]

    McDonald, Kirk

    energy Td (irregular function of atomic number) and displacement efficiency K(T). RaDIATE Meeting Energy Loss for Device Applications", IEEE TRANSACTIONS ON NUCLEAR SCIENCE, VOL. 56, NO. 6, DECEMBER 2009.J. Boschini et al., "Nuclear and Non-Ionizing Energy-Loss for Coulomb Scattered Particles from Low Energy up

  9. Simulation of Heat Treatment Distortion R.A. Hardin1

    E-Print Network [OSTI]

    Beckermann, Christoph

    Simulation of Heat Treatment Distortion R.A. Hardin1 and C. Beckermann2 1 Research Engineer, 2 Abstract This paper gives an overview of the problem of heat treatment stress and distortion and a review reported in the literature of heat treatment distortion on Navy-C rings made from 4140 and 8620 steel

  10. ELF/VLF PHASED ARRAY GENERATION VIA FREQUENCY-MATCHED STEERING OF A CONTINUOUS HF

    E-Print Network [OSTI]

    -OFF modulation of this HF energy can impose an ELF/VLF alternating current onto those natural currents. This technique turns the lower atmosphere into a large antenna, which radiates energy downward into the Earth.6 MW HAARP HF heating facility in Alaska, we show that proper utilization of motion of the HF beam can

  11. R.A. Spicer -Publications. January, 2010 1 R.A. Spicer Publications -Articles, Papers and Books

    E-Print Network [OSTI]

    Spicer, Robert A

    ., Wang, Y.F., Spicer, R.A., Mosbrugger, V., Li, C.S., and Sun, Q.G., 2007, Climatic Reconstruction and Overlapping Distribution Analysis. American Journal of Botany, 94: 599-608. (30%) 104. Spicer, R and the Cold Month Mean Temperature. Journal of Geology, 112: 685-702. (60%) 97. Spic

  12. The Cult of Radrap (Ra dgra), nep of Wangdue Phodrang (Bhutan)

    E-Print Network [OSTI]

    Dorji, Tandin

    2008-01-01

    THE CULT OF RADRAP (RA DGRA), “NEP” OF WANGDUE PHODRANG (BHUTAN) Tandin Dorji Curriculum Officer, CAPSD, Paro, Bhutan Introduction ropitiated as a destroyer and worshipped as a creator, Radrap (Ra dgra), the guardian deity...

  13. Audit Report: OAS-RA-13-15 | Department of Energy

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

    Audit Report: OAS-RA-13-15 Audit Report: OAS-RA-13-15 March 21, 2013 The Department of Energy's Industrial Carbon Capture and Storage Program Funded by the American Recovery and...

  14. Special Report: OAS-RA-10-01 | Department of Energy

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

    OAS-RA-10-01 Special Report: OAS-RA-10-01 October 21, 2009 The Department of Energy's Quality Assurance Process for Prime Recipients' Reporting for the American Recovery and...

  15. Audit Report: OAS-RA-13-28 | Department of Energy

    Energy Savers [EERE]

    Audit Report: OAS-RA-13-28 Audit Report: OAS-RA-13-28 July 18, 2013 Costs Incurred by Selected Tribal Energy Efficiency and Conservation Block Grant Recipients Under the American...

  16. Examination Report: OAS-RA-13-01 | Department of Energy

    Office of Environmental Management (EM)

    Report: OAS-RA-13-01 Examination Report: OAS-RA-13-01 October 9, 2012 California Energy Commission - Energy Efficiency and Conservation Block Grant Program Funds Provided by...

  17. Characteristics of Interconnected Delta-Hydride Precipitates in Zr

    SciTech Connect (OSTI)

    L.J. Carroll; M.R. Tonks; T.M. Lillo; B.S. Fromm; DC Haggard; T.C. Morris; W.D. Swank; T.L. Trowbridge; M.C. Carroll

    2014-09-01

    Characterization of extended delta-ZrH1.66 structures in unalloyed zirconium by electron backscatter diffraction analysis confirms that they consist of many interconnected precipitates of multiple, but distinctly related, orientations. The expected orientation relationship of (0001)a-Zr//(111)delta-ZrH1.66 is confirmed between the hydride and one of the surrounding a-Zr matrix grains. The delta-ZrH1.66 precipitates do not extend in a discrete crystalline orientation, but are regularly divided by 60° type {111} twins in which adjacent delta-ZrH1.66 grains share a {111} plane. The observed matching of the close-packed FCC planes of impinging or twinned hydrides within an interconnected structure enables the minimization of the overall interfacial energy through successive nucleation and growth events and twinning.

  18. Bremsstrahlung emission during $?$-decay of $^{226}{\\rm Ra}$

    E-Print Network [OSTI]

    Giorgio Giardina; Giovanni Fazio; Giuseppe Mandaglio; Marina Manganaro; Serghei P. Maydanyuk; Vladislav S. Olkhovsky; Nikolay V. Eremin; Anton A. Paskhalov; Dmitry A. Smirnov; Carmelo Sacca

    2008-04-16

    We obtained the spectrum of probability of the bremsstrahlung emission accompanying the $\\alpha$-decay of $^{226}{\\rm Ra}$ (E$_{\\alpha}$=4.8 MeV) by measuring the $\\alpha$-$\\gamma$ coincidences and using the model presented in our previous study on the $\\alpha-$decay of $^{214}{\\rm Po}$ (E$_{\\alpha}$=7.7 MeV). We compare the experimental data with the quantum mechanical calculation and find a good agreement between theory and experiment. We discuss the differences between the photon spectra connected with the $\\alpha$-decay of the $^{226}{\\rm Ra}$ and $^{214}{\\rm Po}$ nuclei. For the two mentioned nuclei we analyze the bremsstrahlung emission contributions from the tunneling and external regions of the nucleus barrier into the total spectrum, and we find the destructive interference between these contributions. We also find that the emission of photons during tunneling of the $\\alpha$-particle gives an important contribution to the bremsstrahlung spectrum in the whole E$_{\\gamma}$ energy range of the studied $^{226}$Ra nucleus.

  19. Graphene-Study, Kaprun, March 27th 2015, noise / ballistics in graphene, B. Plaais 1/80 WP4 -HF Electronics HF-Graphene Electronics

    E-Print Network [OSTI]

    Plaçais, Bernard

    Graphene-Study, Kaprun, March 27th 2015, noise / ballistics in graphene, B. Plaçais 1/80 WP4 - HF Electronics HF-Graphene Electronics noise (L1) ballistic's (L2) (electron-phonon) (Dirac Fermion Optics) Bernard Plaçais placais@lpa.ens.fr #12;Graphene-Study, Kaprun, March 27th 2015, noise / ballistics

  20. Ra Solar Systems Solutions SL | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page onRAPID/Geothermal/Exploration/Colorado <RAPID/Geothermal/Water Use/NevadaaTools <REpowerFormRSIRYPOS Inc Jump to:Ra

  1. PROJECT PROFILE: Ra Power Management, Inc. (Incubator 10) | Department of

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE: Alternative Fuelsof EnergyAprilEnergy EEREPlateauFolsom Labs (IncubatorEnergy Ra Power

  2. Analysis of Third-Generation HF ALE Technologies Eric E. Johnson

    E-Print Network [OSTI]

    Johnson, Eric E.

    Analysis of Third-Generation HF ALE Technologies Eric E. Johnson New Mexico State University · Higher throughput for short and long data messages · Better support for Internet protocols

  3. Survey reveals nature of corrosion in HF alky units

    SciTech Connect (OSTI)

    Dobis, J.D. (BP Oil Co., Marcus Hook, PA (United States)); Clarida, D.R. (Conoco Inc., Ponca City, OK (United States)); Richert, J.P. (Saudi Aramco/Mobil, Yanbu (Saudi Arabia))

    1995-03-06

    The results of a National Association of Corrosion Engineers survey of 62 HF alkylation units reveal relatively low incidence of service-related cracking of carbon steel. Hydrogen blistering, however, is prevalent, especially in the main acid circuit and overhead condensers. Based on these and other survey results, several recommendations are made to enable refiners to monitor and reduce corrosion in these special units. The paper discusses the survey results, construction materials, post-weld heat treatments, small-diameter piping, construction inspection, bolting, gaskets, block valves, maintenance practices, cracking, blistering, areas of vulnerability, and recommendations.

  4. The Bayo Canyon/radioactive lanthanum (RaLa) program

    SciTech Connect (OSTI)

    Dummer, J.E.; Taschner, J.C.; Courtright, C.C.

    1996-04-01

    LANL conducted 254 radioactive lanthanum (RaLa) implosion experiments Sept. 1944-March 1962, in order to test implosion designs for nuclear weapons. High explosives surrounding common metals (surrogates for Pu) and a radioactive source containing up to several thousand curies of La, were involved in each experiment. The resulting cloud was deposited as fallout, often to distances of several miles. This report was prepared to summarize existing records as an aid in evaluating the off-site impact, if any, of this 18-year program. The report provides a historical setting for the program, which was conducted in Technical Area 10, Bayo Canyon about 3 miles east of Los Alamos. A description of the site is followed by a discussion of collateral experiments conducted in 1950 by US Air Force for developing an airborne detector for tracking atmospheric nuclear weapons tests. All known off-site data from the RaLa program are tabulated and discussed. Besides the radiolanthanum, other potential trace radioactive material that may have been present in the fallout is discussed and amounts estimated. Off-site safety considerations are discussed; a preliminary off-site dose assessment is made. Bibliographical data on 33 persons important to the program are presented as footnotes.

  5. Examination Report: OAS-RA-13-05 | Department of Energy

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

    Examination Report: OAS-RA-13-05 January 17, 2013 Prince George's County Department of Housing and Community Development - Weatherization Assistance Program Funds Provided by the...

  6. Examination Report: OAS-RA-13-06 | Department of Energy

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

    Examination Report: OAS-RA-13-06 January 17, 2013 Montgomery County Department of Housing and Community Affairs - Weatherization Assistance Program Funds Provided by the...

  7. Strong H...F hydrogen bonds as synthons in polymeric quantum magnets: structural, magnetic, and theoretical characterization of [Cu(HF)(pyrazine)]SbF, [CuF(HF)(FH)(pyrazine)].(SbF), and [CuAg(HF)(pyrazine)](SbF).

    SciTech Connect (OSTI)

    Manson, J. L.; Schlueter, J. A.; Funk, K. A.; Southerland, H. I.; Twamley, B.; Lancaster, T.; Blundell, S. J.; Baker, P. J.; Pratt, F. L.; Singleton, J.; McDonald, R. D.; Goddard, P. A.; Sengupta, P.; Batista, C. D.; Ding, L.; Lee, C.; Whangbo, M.-H.; Franke, I.; Cox, S.; Baines, C.; Trail, D.; Eastern Washington Univ.; Univ. of Idaho; Oxford Univ.; Rutherford Appleton Lab.; LANL; Univ. of Southern California; North Carolina State Univ.; Paul Scherrer Inst.

    2009-01-01

    Three Cu{sup 2+}-containing coordination polymers were synthesized and characterized by experimental (X-ray diffraction, magnetic susceptibility, pulsed-field magnetization, heat capacity, and muon-spin relaxation) and electronic structure studies (quantum Monte Carlo simulations and density functional theory calculations). [Cu(HF{sub 2})(pyz){sub 2}]SbF{sub 6} (pyz = pyrazine) (1a), [Cu{sub 2}F(HF)(HF{sub 2})(pyz){sub 4}](SbF{sub 6}){sub 2} (1b), and [CuAg(H{sub 3}F{sub 4})(pyz){sub 5}](SbF{sub 6}){sub 2} (2) crystallize in either tetragonal or orthorhombic space groups; their structures consist of 2D square layers of [M(pyz){sub 2}]{sup n+} that are linked in the third dimension by either HF{sub 2}{sup -} (1a and 1b) or H{sub 3}F{sub 4}{sup -} (2). The resulting 3D frameworks contain charge-balancing SbF{sub 6}{sup -} anions in every void. Compound 1b is a defective polymorph of 1a, with the difference being that 50% of the HF{sub 2}{sup -} links are broken in the former, which leads to a cooperative Jahn-Teller distortion and d{sub x{sup 2}-y{sup 2}} orbital ordering. Magnetic data for 1a and 1b reveal broad maxima in x at 12.5 and 2.6 K and long-range magnetic order below 4.3 and 1.7 K, respectively, while 2 displays negligible spin interactions owing to long and disrupted superexchange pathways. The isothermal magnetization, M(B), for 1a and 1b measured at 0.5 K reveals contrasting behaviors: 1a exhibits a concave shape as B increases to a saturation field, B{sub c}, of 37.6 T, whereas 1b presents an unusual two-step saturation in which M(B) is convex until it reaches a step near 10.8 T and then becomes concave until saturation is reached at 15.8 T. The step occurs at two-thirds of M{sub sat}, suggesting the presence of a ferrimagnetic structure. Compound 2 shows unusual hysteresis in M(B) at low temperature, although x vs T does not reveal the presence of a magnetic phase transition. Quantum Monte Carlo simulations based on an anisotropic cubic lattice were applied to the magnetic data of 1a to afford g = 2.14, J = ?13.4 K (Cu-pyz-Cu), and J = ?0.20 K (Cu?F {hor_ellipsis} H {hor_ellipsis} F?Cu), while x vs T for 1b could be well reproduced by a spin-1/2 Heisenberg uniform chain model for g = 2.127(1), J{sub 1} = ?3.81(1), and zJ{sub 2} = ?0.48(1) K, where J{sub 1} and J{sub 2} are the intra- and interchain exchange couplings, respectively, which considers the number of magnetic nearest-neighbors (z). The M(B) data for 1b could not be satisfactorily explained by the chain model, suggesting a more complex magnetic structure in the ordered state and the need for additional terms in the spin Hamiltonian. The observed variation in magnetic behaviors is driven by differences in the H {hor_ellipsis} F hydrogen-bonding motifs.

  8. Phosphonic-Based HF Acid: Interactions With Clay Minerals And Flow In Sandstone Cores 

    E-Print Network [OSTI]

    Zhou, Lijun

    2015-05-13

    , phosphonic-based HF acid systems (HF and a phosphonic acid) have been used as an alternative to mud acid. However, very limited research has been performed to investigate the interactions of phosphonic-based acid systems with clay minerals in sandstone...

  9. Finland HF and Esrange MST radar observations of polar mesosphere summer echoes

    E-Print Network [OSTI]

    Kirkwood, Sheila

    Finland HF and Esrange MST radar observations of polar mesosphere summer echoes Tadahiko Ogawa1 (200x) xx:1­8 Finland HF and Esrange MST radar observations of polar mesosphere summer echoes Tadahiko in Finland are presented. The echoes were detected at four frequencies of 9, 11, 13 and 15 MHz at slant

  10. Measurement and analysis of muonic x rays of 176,177,178,179,180Hf

    SciTech Connect (OSTI)

    Tanaka, Y.; Steffen, R.M.; Shera, E.B.; Reuter, W.; Hoehn, M.V.; Zumbro, J.D.

    1984-07-01

    Monopole and quadrupole charge distributions of /sup 176/Hf, /sup 177/Hf, /sup 178/Hf, /sup 179/Hf, and /sup 180/Hf were investigated by muonic atom K and L x-ray measurements. The model-independent Barrett charge radii R/sub k/ and the isotope shifts ..delta..R/sub k/ were measured, and values of and ..delta.. were deduced. A weak odd-even staggering of the nuclear charge radii was observed for the series /sup 176 -178/Hf and /sup 178 -180/Hf. A large negative isomer shift was observed in the 2/sup +/ state of the /sup 176/Hf nucleus, a fact that existing theories do not explain. The quadrupole moments of the first excited states of the hafnium nuclei were determined to be Q/sup 176/(2/sup +/) = -2.10(2) e b, Q/sup 177/((9/2)/sup -/) = 1.30(2) e b, Q/sup 178/(2/sup +/) = -2.02(2) e b, Q/sup 179/((11/2)/sup +/) = 1.88(3) e b, and Q/sup 180/(2/sup +/) = -2.00(2) e b. These quadrupole moments and the simultaneously determined B(E2) values for the respective nuclei are in satisfactory agreement with the predictions of the axially symmetric rotor model.

  11. Effects of heat treatment and HF etching on the strength of silica lightguides

    E-Print Network [OSTI]

    Matthewson, M. John

    Effects of heat treatment and HF etching on the strength of silica lightguides C. R. Kurkjian, M. J, heating of a fiber to moderate temperatures (~300 600 C), for instance during the soldering of pigtails-lowering defects. In this paper we discuss early results from the literature on the effects of heating and HF

  12. DFT STUDY REVISES INTERSTITIAL CONFIGURATIONS IN HCP Zr

    SciTech Connect (OSTI)

    Samolyuk, German D; Golubov, Stanislav I; Osetskiy, Yury N; Stoller, Roger E

    2012-06-01

    Analysis of experimental result on microstructure evolution in irradiated Zr and alloys has demonstrated that available knowledge on self-interstitial defects in Zr is in contradiction. We therefore have initiated an extensive theoretical and modeling program to clarify this issue. In this report we present first ab initio calculations results of single SIA configurations in Zr. We demonstrate importance of simulations cell size, applied exchange-correlation functional and simulated c/a ratio. The results obtained demonstrate clearly that the most stable configurations are in basal plane and provide some evidences for enhanced interstitial transport along basal planes. The results obtained will be used in generation a new interatomic potential for Zr to be used in large-scale atomistic modeling of mechanisms relevant for radiation-induced microstructure evolution.

  13. Crystal structure of Si-doped HfO{sub 2}

    SciTech Connect (OSTI)

    Zhao, Lili [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); School of Information Science and Technology, Northwest University, Xi'an 710127 (China); Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Nelson, Matthew; Fancher, Chris M. [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Aldridge, Henry [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Iamsasri, Thanakorn; Forrester, Jennifer S.; Jones, Jacob L., E-mail: jacobjones@ncsu.edu [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Nishida, Toshikazu [Department of Electrical and Computer Engineering, University of Florida, Gainesville, Florida 32611 (United States); Moghaddam, Saeed [Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida 32611 (United States)

    2014-01-21

    Si-doped HfO{sub 2} was prepared by solid state synthesis of the starting oxides. Using Rietveld refinement of high resolution X-ray diffraction patterns, a substitutional limit of Si in HfO{sub 2} was determined as less than 9 at.?%. A second phase was identified as Cristobalite (SiO{sub 2}) rather than HfSiO{sub 4}, the latter of which would be expected from existing SiO{sub 2}-HfO{sub 2} phase diagrams. Crystallographic refinement with increased Si-dopant concentration in monoclinic HfO{sub 2} shows that c/b increases, while ? decreases. The spontaneous strain, which characterizes the ferroelastic distortion of the unit cell, was calculated and shown to decrease with increasing Si substitution.

  14. Safety Slide 1 Hydrofluoric (HF) Acid Hazards http://www.emsworld.com/web/online/Education/Hydrofluoric-Acid-/5$12949

    E-Print Network [OSTI]

    Cohen, Robert E.

    Safety Slide 1 ­ Hydrofluoric (HF) Acid Hazards http://www.emsworld.com/web may be delayed for up to 24 hours, even with dilute solutions. HF burns affect deep tissue layers

  15. Synthesis of Na-Stabilized Nonporous tZrO2 Supports and Pt/t-ZrO2 Catalysts and Application to Water-Gas-Shift Reaction

    E-Print Network [OSTI]

    Poeppelmeier, Kenneth R.

    steam reforming,10 and epoxidation of olefins.11 ZrO2 exists primarily in three different polymorphs significantly affect the catalytic performance for chemical reactions. Ma et al. prepared t-ZrO2 using Na2CO3 catalytic performance for methanol synthesis from CO hydrogenation compared to amorphous and m-ZrO2

  16. RA After Hours On Call (971) 246-1388 Your Guide to

    E-Print Network [OSTI]

    Latiolais, M. Paul

    on the first floor, and in the first floor lobby of the Ondine Building. Heat Broadway uses baseboard heating floor and retail space on the ground floor. Each studio features loft-like cement floors and a modern (503) 725-4404 RA After Hours On Call FYE (floors 3-7) (971) 246-1386 RA After Hours On Call Upper

  17. RaDON --Repair and Diagnosis in Ontology Networks Qiu Ji, Peter Haase, Guilin Qi, Pascal Hitzler, Steffen Stadtmuller

    E-Print Network [OSTI]

    Hitzler, Pascal

    RaDON -- Repair and Diagnosis in Ontology Networks Qiu Ji, Peter Haase, Guilin Qi, Pascal Hitzler by integrating multiple distributed ontologies. Our RaDON system pro- vides functionalities to repair ontologies. To meet the above mentioned needs, we develop the RaDON system to repair and diagnose not only

  18. High sensitivity measurement of 224Ra and 226Ra in water with an improved hydrous titanium oxide technique at the Sudbury Neutrino Observatory

    E-Print Network [OSTI]

    B. Aharmim; B. T. Cleveland; X. Dai; G. Doucas; J. Farine; H. Fergani; R. Ford; R. L. Hahn; E. D. Hallman; N. A. Jelley; R. Lange; S. Majerus; C. Mifflin; A. J. Noble; H. M. O'Keeffe; R. Rodriguez-Jimenez; D. Sinclair; M. Yeh

    2009-02-01

    The existing hydrous titanium oxide (HTiO) technique for the measurement of 224Ra and 226Ra in the water at the Sudbury Neutrino Observatory (SNO) has been changed to make it faster and less sensitive to trace impurities in the HTiO eluate. Using HTiO-loaded filters followed by cation exchange adsorption and HTiO co-precipitation, Ra isotopes from 200-450 tonnes of heavy water can be extracted and concentrated into a single sample of a few millilitres with a total chemical efficiency of 50%. Combined with beta-alpha coincidence counting, this method is capable of measuring 2.0x10^3 uBq/kg of 224Ra and 3.7x10^3 uBq/kg of 226Ra from the 232Th and 238U decay chains, respectively, for a 275 tonne D2O assay, which are equivalent to 5x10^16 g Th/g and 3x10^16 g U/g in heavy water.

  19. The Walnut Street Model of Ionospheric HF Radio Propagation Eric E. Johnson

    E-Print Network [OSTI]

    Johnson, Eric E.

    1 The Walnut Street Model of Ionospheric HF Radio Propagation Eric E. Johnson New Mexico State on radio frequency, latitude, time of day, season, the solar weather, and so on. Signals reach the receiver

  20. LuHf isotope systematics of fossil biogenic apatite and their effects on geochronology

    E-Print Network [OSTI]

    Schöne, Bernd R.

    ) and argillaceous matrices with low permeability (oil shale of Messel, Germany; Posidonienschiefer of Holzmaden the Eifel, Germany. Low 176 Lu/177 Hf ratios in all materials from the Middle Eocene Messel oil shale (e

  1. HF beam parameters in ELF/VLF wave generation via modulated heating of the ionosphere

    E-Print Network [OSTI]

    of spreading the HF power over a wider area, and we find that a larger beam area yields larger generated et al., 1982], and the observa- tory at Jicamarca, Peru [Lunnen et al., 1984], were both used

  2. The mechanism of HF formation in LiPF6-based organic carbonate electrolytes

    E-Print Network [OSTI]

    Lux, Simon

    2014-01-01

    The mechanism of HF formation in LiPF6-based organicliterature data, a simplified mechanism for the formation of3 . In this proposed mechanism, the blue lines represent the

  3. THIRD-GENERATION TECHNOLOGIES FOR HF RADIO NETWORKING Eric E. Johnson

    E-Print Network [OSTI]

    Johnson, Eric E.

    THIRD-GENERATION TECHNOLOGIES FOR HF RADIO NETWORKING Eric E. Johnson New Mexico State University for Internet protocols and applications This new generation of open standards is the result of ideas

  4. STUDY OF THE REACTION DYNAMICS OF Li + HF, HC1 BY THE CROSSED MOLECULAR BEAMS METHOD

    E-Print Network [OSTI]

    Becker, Christopher H.

    2013-01-01

    the angular and velocity distributions of reaction products~of~flight velocity measurements of the reaction product atLi + HF reaction at EC 2.2 kcal/mole. Velocity distributions

  5. Audit Report: OAS-RA-12-12 | Department of Energy

    Energy Savers [EERE]

    Audit Report: OAS-RA-12-12 May 22, 2012 The Department of Energy's Clean Cities Alternative Fuel Vehicle Grant Program Funded under the American Recovery and Reinvestment Act...

  6. Audit Report: OAS-RA-13-31 | Department of Energy

    Energy Savers [EERE]

    Audit Report: OAS-RA-13-31 September 27, 2013 The Department of Energy's Hydrogen and Fuel Cells Program The Department of Energy spent approximately 1 billion over the last 5...

  7. RSC Advances c3ra45350b Bisindolines from the reaction of 3,5-

    E-Print Network [OSTI]

    Jones, William D.

    RSC Advances c3ra45350b PAPER 1 Bisindolines from the reaction of 3,5- dimethoxyaniline synthesized from the reaction of 3,5-dimethoxyaniline and vicinal diones (2,3-butanedione, benzil, and 4-methylbenzil). ART C3RA45350B_GRABS 1 5 10 15 20 25 30 35 40 45 50 1 5 10 15 20 25 30 35 40 45 50 #12;Queries

  8. Interdiffusion and Reaction between Zr and Al Alloys from 425 degrees to 625 degrees C

    SciTech Connect (OSTI)

    J. Dickson; L. Zhou; A. Ewh; M. Fu; D. D. Keiser, Jr.; Y. H. Sohn; A. Paz y Puente

    2014-06-01

    Zirconium has recently garnered attention for use as a diffusion barrier between U–Mo nuclear fuels and Al cladding alloys. Interdiffusion and reactions between Zr and Al, Al-2 wt.% Si, Al-5 wt.% Si or AA6061 were investigated using solid-to-solid diffusion couples annealed in the temperature range of 425 degrees to 625 degrees C. In the binary Al and Zr system, the Al3Zr and Al2Zr phases were identified, and the activation energy for the growth of the Al3Zr phase was determined to be 347 kJ/mol. Negligible diffusional interactions were observed for diffusion couples between Zr vs. Al-2 wt.% Si, Al-5 wt.% Si and AA6061 annealed at or below 475 degrees C. In diffusion couples with the binary Al–Si alloys at 560 degrees C, a significant variation in the development of the phase constituents was observed including the thick t1 (Al5SiZr2) with Si content up to 12 at.%, and thin layers of (Si,Al)2Zr, (Al,Si)3Zr, Al3SiZr2 and Al2Zr phases. The use of AA6061 as a terminal alloy resulted in the development of both T1 (Al5SiZr2) and (Al,Si)3Zr phases with a very thin layer of (Al,Si)2Zr. At 560 degrees C, with increasing Si content in the Al–Si alloy, an increase in the overall rate of diffusional interaction was observed; however, the diffusional interaction of Zr in contact with multicomponent AA6061 with 0.4–0.8 wt.% Si was most rapid.

  9. Solid-Solution Nanoparticles: Use of a Nonhydrolytic Sol-Gel Synthesis To Prepare HfO2 and HfxZr1-xO2

    E-Print Network [OSTI]

    and Applied Mathematics, and Materials Research Science and Engineering Center, Columbia University, New York ( hafnia 30, zirconia 25), high melting points (2758 and 2700 °C, respectively), and great chemical. Hafnia and zirconia in the bulk can each adopt three different, albeit related, crystal structures

  10. A New Environmentally Friendly AL/ZR-Based Clay Stabilizer 

    E-Print Network [OSTI]

    El-Monier, Ilham Abdallah

    2013-01-18

    tests showed that this new chemical was effective, and unlike previous Al-based and Zr-based stabilizers (hydroxy aluminum and zirconium oxychloride solutions), it did not dissolve in acids and worked very well up to 300oF. Stabilizer A proved...

  11. Neutron capture on {sup 94}Zr: Resonance parameters and Maxwellian-averaged cross sections

    SciTech Connect (OSTI)

    Tagliente, G. [Istituto Nazionale di Fisica Nucleare (INFN), Bari (Italy); University of Gent (Belgium); Milazzo, P. M.; Fujii, K.; Abbondanno, U.; Belloni, F.; Moreau, C. [Istituto Nazionale di Fisica Nucleare (INFN), Trieste (Italy); Aerts, G.; Andriamonje, S.; Berthoumieux, E.; Dridi, W.; Gunsing, F.; Pancin, J.; Perrot, L.; Plukis, A. [CEA/Saclay-IRFU, Gif-sur-Yvette (France); Alvarez, H.; Duran, I.; Paradela, C. [Universidade de Santiago de Compostela (Spain); Alvarez-Velarde, F.; Cano-Ott, D.; Embid-Segura, M. [Centro de Investigaciones Energeticas Medioambientales y Technologicas, Madrid (Spain)

    2011-07-15

    The neutron capture cross sections of the Zr isotopes play an important role in nucleosynthesis studies. The s-process reaction flow between the Fe seed and the heavier isotopes passes through the neutron magic nucleus {sup 90}Zr and through {sup 91,92,93,94}Zr, but only part of the flow extends to {sup 96}Zr because of the branching point at {sup 95}Zr. Apart from their effect on the s-process flow, the comparably small isotopic (n,{gamma}) cross sections make Zr also an interesting structural material for nuclear reactors. The {sup 94}Zr (n,{gamma}) cross section has been measured with high resolution at the spallation neutron source n{sub T}OF at CERN and resonance parameters are reported up to 60 keV neutron energy.

  12. Thermally-driven H interaction with HfO{sub 2} films deposited on Ge(100) and Si(100)

    SciTech Connect (OSTI)

    Soares, G. V. Feijó, T. O.; Baumvol, I. J. R.; Aguzzoli, C.; Krug, C.; Radtke, C.

    2014-01-27

    In the present work, we investigated the thermally-driven H incorporation in HfO{sub 2} films deposited on Si and Ge substrates. Two regimes for deuterium (D) uptake were identified, attributed to D bonded near the HfO{sub 2}/substrate interface region (at 300?°C) and through the whole HfO{sub 2} layer (400–600?°C). Films deposited on Si presented higher D amounts for all investigated temperatures, as well as, a higher resistance for D desorption. Moreover, HfO{sub 2} films underwent structural changes during annealings, influencing D incorporation. The semiconductor substrate plays a key role in this process.

  13. Crystallization of Zr2PdxCu(1-x) and Zr2NixCu(1-x) Metallic Glass

    SciTech Connect (OSTI)

    Min Xu

    2008-08-18

    One interesting aspect of rretallic glasses is the numerous instances of the deviation of the phase selection from the amorphous state to thermodynamically stable phases during the crystallization process. Their devitrification pathways allow us to study the relationship between the original amorphous structure and their crystalline counter parts. Among the various factors of phase selections, size and electronic effects have been most extensively studied. Elucidating the phase selection process of a glassy alloy will be helpful to fill in the puzzle of the changes from disordered to ordered structures. In this thesis, Two model Zr{sub 2}Pd{sub x}Cu{sub (1-x)} and Zr{sub 2}Ni{sub x}Cu{sub (1-x)} (x = 0, 0.25, 0.5, 0.75 and 1) glassy systems were investigated since: (1) All of the samples can be made into a homogenous metallic glass; (2) The atomic radii differ from Pd to Cu is by 11%, while Ni has nearly the identical atomic size compare to Cu. Moreover, Pd and Ni differ by only one valence electron from Cu. Thus, these systems are ideal to test the idea of the effects of electronic structure and size factors; (3) The small number of components in these pseudo binary systems readily lend themselves to theoretical modeling. Using high temperature X-ray diffraction {HTXRD) and thermal analysis, topological, size, electronic, bond and chemical distribution factors on crystallization selections in Zr{sub 2}Pd{sub x}Cu{sub (1-x)} and Zr{sub 2}Ni{sub x}Cu{sub (1-x)} metallic glass have been explored. All Zr{sub 2}Pd{sub x}Cu{sub (1-x)} compositions share the same Cu11b phase with different pathways of meta-stable, icosahedral quasicrystalline phase (i-phase), and C16 phase formations. The quasicrystal phase formation is topologically related to the increasing icosahedral short range order (SRO) with Pd content in Zr{sub 2}Pd{sub x}Cu{sub (1·x)} system. Meta-stable C16 phase is competitive with C11b phase at x = 0.5, which is dominated by electronic structure rather than size effects. Cu-rich and Ni-rich compositions in Zr{sub 2}Ni{sub x}Cu{sub (1-x)} trend to divitrify to C11b or C16 phases respectively. In the proposed pseudo binary phase diagram, the domain of C16, C11b and co-existence phases are mainly related with the topology in the amorphous structure and formation enthalpies of crystalline phases.

  14. Electric-field gradients at the Zr sites in Zr3Fe: Measured using perturbed-angular-correlation spectroscopy and calculated using band theory

    E-Print Network [OSTI]

    Motta, Arthur T.

    Electric-field gradients at the Zr sites in Zr3Fe: Measured using perturbed-angular-correlation spectroscopy and calculated using band theory Arthur T. Motta, Stephen E. Cumblidge, and Gary L. Catchen; published 13 December 2001 We have measured the electric-field-gradient EFG parameters VZZ

  15. IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 34, NO. 4, AUGUST 2006 1105 A Study of ZrN/Zr Coatings Deposited on

    E-Print Network [OSTI]

    Zheng, Yufeng

    IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 34, NO. 4, AUGUST 2006 1105 A Study of ZrN/Zr Coatings/metal coatings were deposited onto NiTi shape-memory alloy using plasma immersion ion im- plantation, such as unbalanced magnetron sputtering, ion plat- ing, ion-beam-assisted deposition, cathodic-vacuum-arc evapo

  16. Triaxial strongly deformed bands in {sup 164}Hf and the effect of elevated yrast line

    SciTech Connect (OSTI)

    Ma Wenchao

    2012-10-20

    Two exotic rotational bands have been identified in {sup 164}Hf and linked to known states. They are interpreted as being associated with the calculated triaxial strongly deformed (TSD) potential energy minimum. The bands are substantially stronger and are located at much lower spins than the previously discovered TSD bands in {sup 168}Hf. In addition to the proton and neutron shell gaps at large trixiality, it was proposed that the relative excitation energy of TSD bands above the yrast line plays an important role in the population of TSD bands.

  17. Ra-226 concentrations in otter, Lutra canadensis, trapped near uranium tailings at Elliot Lake, Ontario

    SciTech Connect (OSTI)

    Wren, C.D.; Cloutier, N.R.; Lim, T.P.; Dave, N.K.

    1987-02-01

    The Elliot Lake area of Ontario, is currently the major uranium producing region of Canada. It is estimated there are 120 million tons of uranium tailings spread over 600 ha in the vicinity of Elliot Lake. The transfer and fate of uranium-series radionuclides from tailing sites remain primary ecological concerns in these areas. It has been demonstrated that the levels of radionuclides, including Ra-226, are elevated in vegetation, small mammals and fish living on or near tailing disposal sites. However, the transfer potential of Ra-226 to predatory species has not been examined in detail. The objective of this study was to measure Ra-226 levels in otters (Lutra canadensis), captured near tailing sites, to provide further information on the fate of radionuclides in the environment.

  18. RAPID METHOD FOR DETERMINATION OF {sup 228}Ra IN WATER SAMPLES

    SciTech Connect (OSTI)

    Maxwell, S.

    2012-09-05

    A new rapid method for the determination of {sup 228}Ra in natural water samples has been developed at the SRNL/EBL (Savannah River National Lab/ Environmental Bioassay Laboratory) that can be used for emergency response or routine samples. While gamma spectrometry can be employed with sufficient detection limits to determine {sup 228}Ra in solid samples (via {sup 228}Ac) , radiochemical methods that employ gas flow proportional counting techniques typically provide lower MDA (Minimal Detectable Activity) levels for the determination of {sup 228}Ra in water samples. Most radiochemical methods for {sup 228}Ra collect and purify {sup 228}Ra and allow for {sup 228}Ac daughter ingrowth for ~36 hours. In this new SRNL/EBL approach, {sup 228}Ac is collected and purified from the water sample without waiting to eliminate this delay. The sample preparation requires only about 4 hours so that {sup 228}Ra assay results on water samples can be achieved in < 6 hours. The method uses a rapid calcium carbonate precipitation enhanced with a small amount of phosphate added to enhance chemical yields (typically >90%), followed by rapid cation exchange removal of calcium. Lead, bismuth, uranium, thorium and protactinium isotopes are also removed by the cation exchange separation. {sup 228}Ac is eluted from the cation resin directly onto a DGA Resin cartridge attached to the bottom of the cation column to purify {sup 228}Ac. DGA Resin also removes lead and bismuth isotopes, along with Sr isotopes and {sup 90}Y. La is used to determine {sup 228}Ac chemical yield via ICP-MS, but {sup 133}Ba can also be used instead if ICP-MS assay is not available. Unlike some older methods, no lead or strontium holdback carriers or continual readjustment of sample pH is required.

  19. Hydrocarbon reaction with HF-cleaned Si(lOQ) and effects on metal-oxide-semiconductor device quality

    E-Print Network [OSTI]

    Rubloff, Gary W.

    Hydrocarbon reaction with HF-cleaned Si(lOQ) and effects on metal-oxide-semiconductor device-cleaned Si( 100) towards hydrocarbon adsorption is examined by surface analysis; most hydrocarbons adsorb oxidation after HF treatment.4'5 In this letter, passivation against hydrocarbon contamination is studied

  20. Audit Report: OAS-RA-12-12 | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematics AndBerylliumDepartmentResolution of Significant36 AuditAuditOAS-RA-09-03OAS-RA-11-15

  1. Radiation damage in cubic-ZrO2 and yttria-stabilized zirconia from molecular dynamics simulations

    SciTech Connect (OSTI)

    Aidhy, Dilpuneet S; Zhang, Yanwen; Weber, William J

    2015-01-01

    We perform molecular dynamics simulation on cubic ZrO2 and yttria-stabilized zirconia (YSZ) to elucidate defect cluster formation resulting from radiation damage, and evaluate the impact of Y-dopants. Interstitial clusters composed of split-interstitial building blocks, i.e., Zr-Zr or Y-Zr are formed. Oxygen vacancies control cation defect migration; in their presence, Zr interstitials aggregate to form split-interstitials whereas in their absence Zr interstitials remain immobile, as isolated single-interstitials. Y-doping prevents interstitial cluster formation due to sequestration of oxygen vacancies.

  2. http://znaturforsch.com/IEO/B302.pdf Compression Behavior of Zr-doped Nanoanatase

    E-Print Network [OSTI]

    Steinle-Neumann, Gerd

    -pressure, Nanocrystals, Titania, Zirconia, Anatase, Dopant Introduction Titania TiO2, zirconia ZrO2, as well as zirconium

  3. Microstructural studies on cast Zr[sub 3]Al-3wt%Nb

    SciTech Connect (OSTI)

    Tewari, R.; Dey, G.K.; Mukhopadhyay, P.; Banerjee, S. . Metallurgy Div.)

    1994-05-01

    In the binary Zr-Al system, Zr[sub 3]Al is the intermetallic phase richest in zirconium. In view of its low absorption cross section for thermal neutrons and its good strength and corrosion resistance, Zr[sub 3]Al may have possible applications as a structural material in thermal reactors. This phase has the ordered cubic L1[sub 2] structure and forms through the peritectoid reaction: [beta]-Zr + Zr[sub 2]Al[minus] > Zr[sub 3]Al, the reaction temperature being 1,292 K. Structurally Zr[sub 3]Al is quite similar to the [alpha][sub 2] or the Ti[sub 3]Al phase (ordered hexagonal DO[sub 19] structure) in the Ti-Al system, the two structures differing only in the stacking sequence of the close packed atomic layers. But for its inherent brittleness, Ti[sub 3]Al is a promising structural material for aerospace applications. It has, however, been demonstrated that niobium additions can reduce the brittleness of this phase. Studies on the Ti[sub 3]Al-Nb system have also shown that niobium stabilizes the high temperature [beta] phase (bcc structure) which, on cooling, can decompose through various phase reactions, generating some interesting microstructures. Similar studies on the Zr[sub 3]Al-Nb system have not been reported yet. The present paper describes some microstructural observations made on a cast Zr[sub 3]Al-3wt%Nb alloy.

  4. Automatic Calibrations for Improved Quality Assurance of Coastal HF Radar Currents

    E-Print Network [OSTI]

    California at Santa Barbara, University of

    to the public via the U.S. Integrated Ocean Observing System (USIOOS): http://www.ioos.gov/hfradar/. These real Monitoring, Monitoring Harmful Algal Blooms, Fisheries Management, Modeling, Marine Navigation, Ocean Energy. INTRODUCTION Currently, over 130 HF radar units are providing coastal surface current maps to the public via

  5. HF Multiresonant Electronic Ballast for Fluorescent Lamps with Constant Filament Preheat Voltage

    E-Print Network [OSTI]

    HF Multiresonant Electronic Ballast for Fluorescent Lamps with Constant Filament Preheat Voltage resonance arrangement that acts as a current source. During warm up the filaments are driven by a secondary the filament and shorts out the voltage across the lamp. Simulation and experimental results suggest

  6. Adsorbate shape selectivity: Separation of the HF/134a azeotrope over carbogenic molecular sieve

    SciTech Connect (OSTI)

    Hong, A.; Mariwala, R.K.; Kane, M.S.; Foley, H.C. [Univ. of Delaware, Nework, DE (United States)

    1995-03-01

    Experimental evidence is provided for adsorptive shape selectivity in the separation of the azeotrope between HF and 1,1,1,2-tetrafluoroethane (134a) over pyrolyzed poly(furfuryl alcohol)-derived carbogenic molecular sieve (PPFA-CMS). The separation can be accomplished over coconut charcoal or Carbosieve G on the basis of the differences in the extent of equilibrium adsorption of HF and 134a. On these adsorbents 134a is more strongly bound than HF, thus it elutes much more slowly from the bed. The heat of adsorption for 134a in the vicinity of 200 C on Carbosieve G is {approximately}8.8 kcal/mol. In contrast, when the same azeotropic mixture is separated over PPFA-CMS prepared at 500 C, 134a is not adsorbed. As a result 134a elutes from the bed first, followed by HF. The reversal is brought about by the narrower pore size and pore size distribution of the PPFA-CMS versus that for Carbosieve G. Thus the separation over PPFA-CMS is an example of adsorbate shape selectivity and represents a limiting case of kinetic separation.

  7. INTEROPERABILITY AND PERFORMANCE ISSUES IN HF E-MAIL Eric E. Johnson

    E-Print Network [OSTI]

    Johnson, Eric E.

    INTEROPERABILITY AND PERFORMANCE ISSUES IN HF E-MAIL Eric E. Johnson New Mexico State University exceed those experi- enced in the wired Internet. Beyond the delays imposed by low data bandwidths network.) · The Simple Mail Transfer Protocol SMTP [RFC-821] is the standard within the Internet. Its

  8. Distinguished Lecture in International Justice and Human Rights Prince Zeid Ra'ad Zeid Al-Hussein

    E-Print Network [OSTI]

    Snider, Barry B.

    Distinguished Lecture in International Justice and Human Rights Prince Zeid Ra'ad Zeid Al Brandeis University was honored to host His Royal Highness Prince Zeid Ra'ad Zeid Al Life with the generous support of the Planethood Foundation. Prince Zeid was introduced by Donald

  9. Experimental Implementation of Robotic Sequential Nuclear Search R.A. Cortez, H. G. Tanner,

    E-Print Network [OSTI]

    Tanner, Herbert G.

    Experimental Implementation of Robotic Sequential Nuclear Search R.A. Cortez, H. G. Tanner, A work on automated nuclear search, by taking the principle of a bidirectional, real time interaction is in demonstrating that automated nuclear search is feasible, can be performed with commercially available robotic

  10. Supply of purified Th228 for Ra224 generators. Final CRADA Report .

    SciTech Connect (OSTI)

    Ehst, D. A.; Nuclear Engineering Division

    2009-10-02

    CRADA was terminated when it was determined that the Russians could not perform the terms of the subcontract. It became apparent that the Russians would not be a reliable source of Th228, as a precursor in the decay chain which leads to Ra224. Their government policies will prohibit the export of Th228 in quantities needed for commercial cancer therapy.

  11. August 2006 Grantee Registration Process in NIH eRA Commons

    E-Print Network [OSTI]

    Baker, Chris I.

    August 2006 Grantee Registration Process in NIH eRA Commons Detailed Steps STEP 1. Begin Grantee Registration Steps 1 #12;August 2006 · It may include numbers · It must contain letters · It may. 2. In the User ID box, type the user name you created for your Commons account. Grantee Registration

  12. Thermodynamic Modeling and Experimental Study of the Fe-Cr-Zr System

    SciTech Connect (OSTI)

    Yang, Ying; Tan, Lizhen; Bei, Hongbin; Busby, Jeremy T

    2013-01-01

    Wide applications of zircaloys, stainless steels and their interactions in nuclear reactors require the knowledge on phase stability and thermodynamic property of the Fe-Cr-Zr system. This knowledge is also important to develop new Zr-contained Fe-Cr ferritic steels. This work aims at developing thermodynamic models for describing phase stability and thermodynamic property of the Fe-Cr-Zr system using the Calphad approach coupled with experimental study. Thermodynamic descriptions of the Fe-Cr and Cr-Zr systems were either directly adopted or slightly modified from literature. The Fe-Zr system has been remodeled to accommodate recent ab-initio calculation of formation enthalpies of various Fe-Zr compounds. Reliable ternary experimental data and thermodynamic models were mainly available in the Zr-rich region. Therefore, selected ternary alloys located in the vicinity of the eutectic valley of (Fe,Cr,Zr) and (Fe,Cr)2Zr laves phase in the Fe-rich region have been experimentally investigated in this study. Microstructure has been examined by using scanning electron microscope, energy-dispersive Xray spectroscopy and X-ray diffraction. These experimental results, along with the literature data were then used to develop thermodynamic models for phases in the Fe-Cr-Zr system. Calculated phase equilibria and thermodynamic properties of the ternary system yield satisfactory agreements with available experimental data, which gives the confidence to use these models as building blocks for developing a Zr, Fe and Cr contained multicomponent thermodynamic database for broader applications in nuclear reactors.

  13. Transitions of bandgap and built-in stress for sputtered HfZnO thin films after thermal treatments

    SciTech Connect (OSTI)

    Li, Chih-Hung; Chen, Jian-Zhang [Institute of Applied Mechanics, National Taiwan University, Taipei City 10617, Taiwan (China)] [Institute of Applied Mechanics, National Taiwan University, Taipei City 10617, Taiwan (China); Cheng, I-Chun [Graduate Institute of Photonics and Optoelectronics and Department of Electrical Engineering, National Taiwan University, Taipei City 10617, Taiwan (China)] [Graduate Institute of Photonics and Optoelectronics and Department of Electrical Engineering, National Taiwan University, Taipei City 10617, Taiwan (China)

    2013-08-28

    HfZnO thin films with various Hf contents are sputter-deposited on glass substrates from Hf{sub x}Zn{sub 1?x}O (x = 0, 2.5, 5, 7.5, and 10 at. %) targets at room temperature. The incorporation of Hf in the ZnO film leads to the amorphorization of the materials. The amorphous structures of high-Hf-content films remain after annealing at 600 °C for 30 min. The built-in stresses of as-deposited films are compressive. As the annealing temperature increases, the stresses are relaxed and even become tensile. The films exhibit a high transmission of 80% in the visible region. The optical bandgap increases with the Hf content, but it decreases with the annealing temperature. This can be attributed to the alteration of strain (stress) status in the films and atomic substitution. The reduction of bandgap partly results from the grain growth, which is due to the quantum confinement effect of the small grains. Hf doping increases the resistivity of ZnO owing to the disorder of the material structure and the higher bandgap, which result in more carrier traps and less thermally excited carriers in the conduction bands.

  14. Sub-barrier fusion of 32S+90,96Zr: semi-classical coupled-channels approach

    E-Print Network [OSTI]

    H. Q. Zhang; C. J. Lin; F. Yang; H. M. Jia; X. X. Xu; F. Jia; Z. D. Wu; S. T. Zhang; Z. H. Liu; A. Richard; C. Beck

    2010-05-05

    The fusion excitation functions have been measured with rather good accuracy for 32S+90Zr and 32S+96Zr near and below the Coulomb barrier. The sub-barrier cross sections for 32S+96Zr are much larger compared with 32S+90Zr. Semi-classical coupled-channels calculations including two-phonon excitations are capable to describe sub-barrier enhancement only for 32S+90Zr. The remaining disagreement for 32S+96Zr comes from the positive Q-value intermediate neutron transfers in this system. The comparison with 40Ca+96Zr suggests that couplings to the positive Q-value neutron transfer channels may play a role in the sub-barrier fusion enhancement. A rather simple model calculation taking neutron transfers into account is proposed to overcome the discrepancies of 32S+96Zr.

  15. Zr electrorefining process for the treatment of cladding hull waste in LiCl-KCl molten salts

    SciTech Connect (OSTI)

    Lee, Chang Hwa; Lee, You Lee; Jeon, Min Ku; Kang, Kweon Ho; Choi, Yong Taek; Park, Geun Il [Korea Atomic Energy Research Institute - KAERI, 989-111 Daeduk-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of)

    2013-07-01

    Zr electrorefining for the treatment of Zircaloy-4 cladding hull waste is demonstrated in LiCl-KCl-ZrCl{sub 4} molten salts. Although a Zr oxide layer thicker than 5 ?m strongly inhibits the Zr dissolution process, pre-treatment processes increases the dissolution kinetics. For 10 g-scale experiments, the purities of the recovered Zr were 99.54 wt.% and 99.74 wt.% for fresh and oxidized cladding tubes, respectively, with no electrical contact issue. The optimal condition for Zr electrorefining has been found to improve the morphological feature of the recovered Zr, which reduces the salt incorporation by examining the effect of the process parameters such as the ZrCl{sub 4} concentration and the applied potential.

  16. 688 JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 13, NO. 4, AUGUST 2004 Zirconium Tungstate (ZrW2O8)-Based

    E-Print Network [OSTI]

    Talghader, Joseph J.

    688 JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 13, NO. 4, AUGUST 2004 Zirconium Tungstate (Zr expansion, sputtering, thermal factors, thin film, zirconium tungstate (ZrW2O8). I. INTRODUCTION THERMAL

  17. THE JOURNAL OF CHEMICAL PHYSICS 135, 104303 (2011) The visible spectrum of zirconium dioxide, ZrO2

    E-Print Network [OSTI]

    Maier, John Paul

    2011-01-01

    THE JOURNAL OF CHEMICAL PHYSICS 135, 104303 (2011) The visible spectrum of zirconium dioxide, ZrO2; published online 8 September 2011) The electronic spectrum of a cold molecular beam of zirconium dioxide, Zr

  18. PHYSICAL REVIEW B 91, 085129 (2015) Structural, electronic and hyperfine characterization of pure and Ta-doped ZrSiO4

    E-Print Network [OSTI]

    Svane, Axel Torstein

    2015-01-01

    correlation (TDPAC) using (181 Hf )181 Ta as probe techniques are highly efficient in investigating zirconium

  19. High resolution gas phase infrared spectroscopy of the hydrogen bonded complex HCN---HF and its deuterated isotopic species 

    E-Print Network [OSTI]

    Jackson, Marc William

    1987-01-01

    Scan Over a Portion of the u6 Band 1 System of HCiV---HF 59 The Central Portion of the u6 Band of HCN- ? -HF 1 Showing the 3 Assignment of the Q-branch and a Portion of the P-branch 1 A Portion of the R-branch of the u6 Band of HCN---HF 60 10 A... region. Reported herein is the analysis of the rovibrational substructure of the ul(D-F), u2(C-D) and w3 (C=N) predissociating stretching vibrations of DCiV---DF. Numerous molecular constants were determined for these fundamentals along with a total...

  20. Properties of Porous TiNbZr Shape Memory Alloy Fabricated by Mechanical Alloying

    E-Print Network [OSTI]

    Zheng, Yufeng

    , with subsequent hot or cold rolling, were used to fabricate these Ni-free SMAs. There is no work related to powderNb-6Zr (at.%) shape memory alloys produced using elemental powders by means of mechanical alloying by adding ternary elements, including Molybdenum (Mo), Palladium (Pd), Tin (Sn), Zirconium (Zr), etc. Ping

  1. Phase formation in ZrFe multilayers: Effect of irradiation A. T. Motta

    E-Print Network [OSTI]

    Motta, Arthur T.

    Phase formation in Zr­Fe multilayers: Effect of irradiation A. T. Motta The Pennsylvania State Science Division, Argonne National Laboratory, Argonne, Illinois 60403 M. E. Bru¨ckmann, S. R. Teixeira a detailed in situ study of phase formation in Zr­Fe metallic multilayers using irradiation and thermal

  2. Local structures surrounding Zr in nanostructurally stabilized cubic zirconia: Structural origin of phase stability

    SciTech Connect (OSTI)

    Soo, Y. L.; Chen, P. J.; Huang, S. H.; Shiu, T. J.; Tsai, T. Y.; Chow, Y. H.; Lin, Y. C.; Weng, S. C.; Chang, S. L. [Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Wang, G.; Cheung, C. L. [Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (United States); Sabirianov, R. F.; Mei, W. N. [Department of Physics, University of Nebraska at Omaha, Omaha, Nebraska 68182 (United States); Namavar, F.; Haider, H.; Garvin, K. L. [Department of Orthopaedics Surgery and Rehabilitation, University of Nebraska Medical Center, Omaha, Nebraska 68198 (United States); Lee, J. F. [National Synchrotron Radiation Research Center, Hsinchu 30013, Taiwan (China); Lee, H. Y.; Chu, P. P. [Department of Chemistry, National Central University, Jhongli 32001, Taiwan (China)

    2008-12-01

    Local environment surrounding Zr atoms in the thin films of nanocrystalline zirconia (ZrO{sub 2}) has been investigated by using the extended x-ray absorption fine structure (EXAFS) technique. These films prepared by the ion beam assisted deposition exhibit long-range structural order of cubic phase and high hardness at room temperature without chemical stabilizers. The local structure around Zr probed by EXAFS indicates a cubic Zr sublattice with O atoms located on the nearest tetragonal sites with respect to the Zr central atoms, as well as highly disordered locations. Similar Zr local structure was also found in a ZrO{sub 2} nanocrystal sample prepared by a sol-gel method. Variations in local structures due to thermal annealing were observed and analyzed. Most importantly, our x-ray results provide direct experimental evidence for the existence of oxygen vacancies arising from local disorder and distortion of the oxygen sublattice in nanocrystalline ZrO{sub 2}. These oxygen vacancies are regarded as the essential stabilizing factor for the nanostructurally stabilized cubic zirconia.

  3. Grain growth in ZrFe thin films during in situ ion irradiation in a TEM

    E-Print Network [OSTI]

    Motta, Arthur T.

    Grain growth in Zr­Fe thin films during in situ ion irradiation in a TEM D. Kaoumi a,*, A.T. Motta Laboratory, Argonne, IL 060493, USA Available online 2 November 2005 Abstract In situ ion-beam irradiation was used to study irradiation induced grain growth in co-sputter-deposited Zr/xFe (0% 6 x 6 4

  4. Atomistic Studies of Cation Transport in Tetragonal ZrO2 During Zirconium Corrosion

    SciTech Connect (OSTI)

    Xian-Ming Bai; Yongfeng Zhang; Michael R. Tonks

    2013-10-01

    Zirconium alloys are the major fuel cladding materials in current reactors. The water-side corrosion is one of the major degradation mechanisms of these alloys. During corrosion the transport of oxidizing species in zirconium dioxide (ZrO2) determines the corrosion kinetics. Previously it has been argued that the outward diffusion of cation ions is important for forming protective oxides. In this work, the migration of Zr defects in tetragonal ZrO2 is studied with temperature accelerated dynamics and molecular dynamics simulations. The results show that Zr interstitials have anisotropic diffusion and migrate preferentially along the [001] or c direction in tetragonal ZrO2. The compressive stresses can increase the Zr interstitial migration barrier significantly. The migration barriers of some defect clusters can be much lower than those of point defects. The migration of Zr interstitials at some special grain boundaries is much slower than in a bulk oxide. The implications of these atomistic simulation results in the Zr corrosion are discussed.

  5. THREE-DIMENSIONAL ATOMIC STRUCTURE OF NiO ZrO2(CUBIC) INTERFACES

    E-Print Network [OSTI]

    Pennycook, Steve

    THREE-DIMENSIONAL ATOMIC STRUCTURE OF NiO± ZrO2(CUBIC) INTERFACES E. C. DICKEY{1 , V. P. DRAVID1-dimensional atomic structure of low-energy NiO±ZrO2(cubic) interfaces is determined through a combination of electron the structural and chemical aspects of the interface and associ- ated interfacial relaxation mechaubic) interface

  6. Report on Characterization of U-10 wt.% Zr Alloy

    SciTech Connect (OSTI)

    McKeown, J; Wall, M; Hsiung, L; Turchi, P

    2012-03-01

    This report summarizes the chemical and structural characterization results for a U-10 wt.% Zr alloy to be used in an ultra-high burn-up nuclear fuel concept. The as-cast alloy material was received from Texas A and M University. Characterization and an initial heat treatment of the alloy material were conducted at Lawrence Livermore National Laboratory. The as-received ingot was sectioned for X-ray analysis, metallography, SEM, TEM, and heat treatments, as shown in Figure 1.

  7. Active eutectoid decomposition in Zr-3 wt.% Fe

    SciTech Connect (OSTI)

    Kumar, L.; Ramanujan, R.V.; Tewari, R.; Mukhopadhyay, P.; Banerjee, S.

    1999-02-19

    In the work reported here, the microstructural features associated with the active eutectoid decomposition of a near eutectoid alloy (Zr-3 wt.%Fe) on {beta} quenching were examined. The effects of aging after {beta} quenching, and of furnace cooling from the {beta} phase field, on the microstructure of the alloy were also studied. The microstructural characterization was carried out using optical microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM). The room temperature mechanical properties corresponding to some of the microstructures were evaluated by mechanical testing.

  8. Displacive radiation-induced structural contraction in nanocrystalline ZrN

    SciTech Connect (OSTI)

    Lu Fengyuan; Sun Hongtao; Lian Jie [Department of Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytech Institute, Troy, New York 12180 (United States); Huang, Mengbing; Yaqoob, Faisal [Ion Beam Laboratory, University at Albany-SUNY, Albany, New York 12222 (United States); Lang, Maik; Ewing, Rodney C. [Departments of Earth and Environmental Sciences and Materials Sciences and Engineering, University of Michigan, Ann Arbor, Michigan 48109-1005 (United States); Namavar, Fereydoon [Department of Orthopaedic Surgery and Rehabilitation, University of Nebraska Medical Center, Omaha, Nebraska 68198 (United States); Trautmann, Christina [GSI Helmholtz Center for Heavy Ion Research, 64291 Darmstadt (Germany); Technische Universitaet Darmstadt, 64289 Darmstadt (Germany)

    2012-07-23

    Nanocrystalline ZrN thin films with 5 nm grain size, prepared by ion beam assisted deposition, maintained their isometric structure upon intensive displacive and ionizing irradiations, indicating an extremely high stability similar to bulk ZrN. However, a unique structural contraction up to 1.42% in lattice parameter occurred only in nano-sized ZrN upon displacive irradiations. A significant nitrogen loss occurred with reduced N:Zr atomic ratio to 0.88, probably due to the production of displaced nitrogen atoms and fast diffusion along grain boundaries in nanocrystalline ZrN matrix. The accumulation of nitrogen vacancies and related strain relaxation may be responsible for the structural contraction.

  9. Effect of surface strain on oxygen adsorption on Zr (0001) surface

    SciTech Connect (OSTI)

    Wang, Xing [Univ. of Wisconsin-Madison, Madison, WI (United States). Dept. of Engineering Physics; Khafizov, Marat [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Szlufarska, Izabela [Univ. of Wisconsin-Madison, Madison, WI (United States). Dept. of Engineering Physics; Univ. of Wisconsin-Madison, Madison, WI (United States). Dept. of Materials Science and Engineering

    2014-02-01

    The effect of surface strain on oxygen adsorption on Zr (0 0 0 1) surface is investigated by density functional theory (DFT) calculations. It is demonstrated that both surface strain and interactions between oxygen adsorbates influence the adsorption process. Oxygen binding to zirconium becomes stronger as the strain changes from compressive to tensile. When oxygen coverage is low and the oxygen interactions are negligible, surface face-centered cubic sites are the most stable for O binding. At high coverage and under compression, octahedral sites between second and third Zr layers become most favorable because the interactions between adsorbates are weakened by positive charge screening. Calculations with both single-layer adsorption model and multiple-layer adsorption model demonstrate that compressive strain at the Zr/oxide interface will provide a thermodynamic driving force for oxygen to incorporate from the surface into the bulk of Zr, while binding oxygen to the Zr surface will be easier when tensile strain is applied.

  10. GEO 600 and the GEO-HF upgrade program: successes and challenges

    E-Print Network [OSTI]

    Dooley, K L; Adams, T; Affeldt, C; Bisht, A; Bogan, C; Degallaix, J; Gräf, C; Hild, S; Hough, J; Khalaidovski, A; Lastzka, N; Lough, J; Lück, H; Macleod, D; Nuttall, L; Prijatelj, M; Schnabel, R; Schreiber, E; Slutsky, J; Sorazu, B; Strain, K A; Vahlbruch, H; Was, M; Willke, B; Wittel, H; Danzmann, K; Grote, H

    2015-01-01

    The German-British laser-interferometric gravitational wave detector GEO 600 is in its 14th year of operation since its first lock in 2001. After GEO 600 participated in science runs with other first-generation detectors, a program known as GEO-HF began in 2009. The goal was to improve the detector sensitivity at high frequencies with technologically advanced yet minimally invasive upgrades. Simultaneously, the detector would record science quality data in between commissioning activities. As of early 2014, all of the planned upgrades have been carried out and sensitivity improvements of up to a factor of four at the high-frequency end of the observation band have been achieved. Besides science data collection, an experimental program is ongoing with the goal to further improve the sensitivity and evaluate future detector technologies. We summarize the results of the GEO-HF program to date and discuss its successes and challenges.

  11. 225-Ac and 223-Ra Production via 800 MeV Proton Irradiation of Natural Thorium Target

    E-Print Network [OSTI]

    J. W. Weidner; S. G. Mashnik; K. D. John; B. Ballard; E. R. Birnbaum; L. J. Bitteker; A. Couture; M. E. Fassbender; G. S. Goff; R. Gritzo; F. M. Hemez; W. Runde; J. L. Ullmann; L. E. Wolfsberg; F. M. Nortier

    2012-04-10

    Cross sections for the formation of 225,227-Ac, 223,225-Ra, and 227-Th via the proton bombardment of natural thorium targets were measured at a nominal proton energy of 800 MeV. No earlier experimental cross section data for the production of 223,225-Ra, 227-Ac and 227-Th by this method were found in the literature. A comparison of theoretical predictions with the experimental data shows agreement within a factor of two. Results indicate that accelerator-based production of 225-Ac and 223-Ra is a viable production method.

  12. Shape memory response and microstructural evolution of a severe plastically deformed high temperature shape memory alloy (NiTiHf

    E-Print Network [OSTI]

    Simon, Anish Abraham

    2006-04-12

    NiTiHf alloys have attracted considerable attention as potential high temperature Shape Memory Alloy (SMA) but the instability in transformation temperatures and significant irrecoverable strain during thermal cycling under constant stress remains a...

  13. HF Radar Performance in a Low-Energy Environment: CODAR SeaSonde Experience on the West Florida Shelf*

    E-Print Network [OSTI]

    both tidal and subtidal frequency bands. By examining the HF radar radial velocities at low wave energy have evolved along with coastal ocean circulation-observing technologies. Early inferences on surface

  14. Electronic properties of InP (001)/HfO{sub 2} (001) interface: Band offsets and oxygen dependence

    SciTech Connect (OSTI)

    KC, Santosh; Dong, Hong; Longo, Roberto C.; Xiong, Ka [Department of Materials Science and Engineering, The University of Texas at Dallas, Richardson, Texas 75080 (United States); Wang, Weichao [Department of Electronics and Microelectronics and Tianjin Key Laboratory of Photo-Electronic Thin Film Device and Technology, Nankai University, Tianjin 300071 (China); Wallace, Robert M.; Cho, Kyeongjae, E-mail: kjcho@utdallas.edu [Department of Materials Science and Engineering, The University of Texas at Dallas, Richardson, Texas 75080 (United States); Department of Physics, The University of Texas at Dallas, Richardson, Texas 75080 (United States)

    2014-01-14

    Using ab-initio methods, atomic structures and electronic properties of InP (001)/HfO{sub 2} (001) interface are studied within the framework of density functional theory. We examine the InP/HfO{sub 2} model interface electronic structures under varying oxidation conditions. The effects of indium and phosphorous concentrations on interfacial bonding, defect states, band offsets, and the thermodynamic stability at the interface are also investigated. The origin of interfacial gap states in InP (001)/HfO{sub 2} (001) interface are proposed, mainly from the P-rich oxides, which is validated by our experimental work. This highlights the importance of surface passivation prior to high-? deposition based on the in situ spectroscopic results of atomic layer deposition of HfO{sub 2} on InP.

  15. Coexistence of different charge states in Ta-doped monoclinic HfO2: Theoretical and experimental approaches

    E-Print Network [OSTI]

    Svane, Axel Torstein

    and with the addition of small amounts of impurities, it has applications ranging from solid oxide fuel cell attention due to its potential technological applications. HfO2 is a wide-band- gap semiconductor

  16. Mode specificity in the HF + OH ? F + H{sub 2}O reaction

    SciTech Connect (OSTI)

    Song, Hongwei; Li, Jun; Guo, Hua

    2014-10-28

    Full-dimensional quantum dynamics and quasi-classical trajectory calculations are reported for the title reaction on a recently constructed ab initio based global potential energy surface. Strong mode specificity was found, consistent with the prediction of the sudden vector projection model. Specifically, the HF vibration strongly promotes the reaction while the OH vibration has little effect. Rotational excitations of both reactants slightly enhance the reaction.

  17. Nuclear fusion as a probe for octupole deformation in $^{224}$Ra

    E-Print Network [OSTI]

    Kumar, Raj; Vitturi, A

    2015-01-01

    $\\textit{Background}$: Nuclear fusion has been shown to be a perfect probe to study the different nuclear shapes. However, the possibility of testing octupole deformation of a nucleus with this tool has not been fully explored yet. The presence of a stactic octupole deformation in nuclei will enhanced a possible permanent electric dipole moment, leading to a possible demonstration of parity violation. $\\textit{Purpose}$: To check whether static octupole deformation or octupole vibration in fusion give qualitatively different results so that both situations can be experimentally disentangled. $\\textit{Method}$: Fusion cross sections are computed in the Coupled-Channels formalism making use of the Ingoing-Wave Boundary Conditions (IWBC) for the systems $^{16}$O+$^{144}$Ba and $^{16}$O+$^{224}$Ra. $\\textit{Results}$: Barrier distributions of the two considered schemes show different patterns. For the $^{224}$Ra case, the octupole deformation parameter is large enough to create a sizeable difference. $\\textit{Con...

  18. The Department of Energy's Transportation Electrification Program, 0AS-RA-12-11

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankADVANCEDInstallers/ContractorsPhotovoltaicsState of Pennsylvania OAS-RA-L-11-11Renewable

  19. Plant cyclopeptide RA-V kills human breast cancer cells by inducing mitochondria-mediated apoptosis through blocking PDK1–AKT interaction

    SciTech Connect (OSTI)

    Fang, Xian-Ying; Chen, Wei; Fan, Jun-Ting; Song, Ran; Wang, Lu; Gu, Yan-Hong; Zeng, Guang-Zhi; Shen, Yan; Wu, Xue-Feng; Tan, Ning-Hua; Xu, Qiang; Sun, Yang

    2013-02-15

    In the present paper, we examined the effects of a natural cyclopeptide RA-V on human breast cancer cells and the underlying mechanisms. RA-V significantly inhibited the growth of human breast cancer MCF-7, MDA-MB-231 cells and murine breast cancer 4T1 cells. In addition, RA-V triggered mitochondrial apoptotic pathway which was indicated by the loss of mitochondrial membrane potential, the release of cytochrome c, and the activation of caspase cascade. Further study showed that RA-V dramatically inhibited phosphorylation of AKT and 3-phosphoinositide dependent protein kinase 1 (PDK1) in MCF-7 cells. Moreover, RA-V disrupted the interaction between PDK1 and AKT in MCF-7 cells. Furthermore, RA-V-induced apoptosis could be enhanced by phosphatidylinositol 3-kinase inhibitor or attenuated by over-expression of AKT in all the three kinds of breast cancer cells. Taken together, this study shows that RA-V, which can induce mitochondria-mediated apoptosis, exerts strong anti-tumor activity against human breast cancer. The underlying anti-cancer mechanism of RA-V is related to the blockage of the interaction between PDK1 and AKT. - Highlights: ? Plant cyclopeptide RA-V kills human breast cancer cells. ? RA-V triggered mitochondrial apoptotic pathway in human breast cancer cells. ? RA-V inhibited phosphorylation of AKT and PDK1 in breast cancer MCF-7 cells. ? Its mechanism is related to the blockage of the interaction between PDK1 and AKT.

  20. Molecular Evolution, Networks in From: Meyers, R.A. (ed.) Encyclopedia of Complexity and System Science. Springer, Heidelberg

    E-Print Network [OSTI]

    Wagner, Andreas

    Molecular Evolution, Networks in From: Meyers, R.A. (ed.) Encyclopedia of Complexity and System of Biochemistry Computational Biology and Bioinformatics Building Y27 Winterthurerstrasse 190 CH-8057 Zurich

  1. Structures and magnetic properties of Co-Zr-B magnets studied by first-principles calculations

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

    Zhao, Xin; Ke, Liqin; Nguyen, Manh Cuong; Wang, Cai-Zhuang; Ho, Kai-Ming

    2015-06-23

    The structures and magnetic properties of Co-Zr-B alloys near the composition of Co5Zr with B at. % ?6% were studied using adaptive genetic algorithm and first-principles calculations. The energy and magnetic moment contour maps as a function of chemical composition were constructed for the Co-Zr-B magnet alloys through extensive structure searches and calculations. We found that Co-Zr-B system exhibits the same structure motif as the “Co11Zr2”polymorphs, and such motif plays a key role in achieving strong magnetic anisotropy. Boronatoms were found to be able to substitute cobalt atoms or occupy the “interruption” sites. First-principles calculations showed that the magnetocrystalline anisotropymore »energies of the boron-doped alloys are close to that of the high-temperature rhombohedral Co5Zr phase and larger than that of the low-temperature Co5.25Zr phase. Our calculations provide useful guidelines for further experimental optimization of the magnetic performances of these alloys.« less

  2. Isothermal oxidation behavior of ternary Zr-Nb-Y alloys at high temperature

    SciTech Connect (OSTI)

    Prajitno, Djoko Hadi, E-mail: djokohp@batan.go.id [Research Center for Nuclear Materials and Radiometry, Jl. Tamansari 71, Bandung 40132 (Indonesia); Soepriyanto, Syoni; Basuki, Eddy Agus [Metallurgy Engineering, Institute Technology Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia); Wiryolukito, Slameto [Materials Engineering, Institute Technology Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia)

    2014-03-24

    The effect of yttrium content on isothermal oxidation behavior of Zr-2,5%Nb-0,5%Y, Zr-2,5%Nb-1%Y Zr-2,5%Nb-1,5%Y alloy at high temperature has been studied. High temperature oxidation carried out at tube furnace in air at 600,700 and 800°C for 1 hour. Optical microscope is used for microstructure characterization of the alloy. Oxidized and un oxidized specimen was characterized by x-ray diffraction. In this study, kinetic oxidation of Zr-2,5%Nb with different Y content at high temperature has also been studied. Characterization by optical microscope showed that microstructure of Zr-Nb-Y alloys relatively unchanged and showed equiaxed microstructure. X-ray diffraction of the alloys depicted that the oxide scale formed during oxidation of zirconium alloys is monoclinic ZrO2 while unoxidised alloy showed two phase ? and ? phase. SEM-EDS examination shows that depletion of Zr composition took place under the oxide layer. Kinetic rate of oxidation of zirconium alloy showed that increasing oxidation temperature will increase oxidation rate but increasing yttrium content in the alloys will decrease oxidation rate.

  3. Ab initio density functional theory study of uranium solubility in Gd2Zr2O7 pyrochlore

    E-Print Network [OSTI]

    Chen, Qing-yun; Meng, Chuan-min; Liao, Chang-zhong; Wang, Lie-lin; Xie, Hua; Lv, Hui-yi; Wu, Tao; Ji, Shi-yin; Huang, Yu-zhu

    2015-01-01

    In this study, an ab initio calculation is performed to investigate the uranium solubility in different sites of Gd2Zr2O7 pyrochlore. The Gd2Zr2O7 maintains its pyrochlore structure at low uranium dopant levels, and the lattice constants of Gd2(Zr2-yUy)O7 and (Gd2-yUy)Zr2O7 are generally expressed as being linearly related to the uranium content y. Uranium is found to be a preferable substitute for the B-site gadolinium atoms in cation-disordered Gd2Zr2O7 (where gadolinium and zirconium atoms are swapped) over the A-site gadolinium atoms in ordered Gd2Zr2O7 due to the lower total energy of (Gd2-yZry)(Zr2-yUy)O7. The theoretical findings present a reasonable explanation of recent experiment results.

  4. Structural relaxation and nanoindentation response in Zr-Cu-Ti amorphous thin films

    SciTech Connect (OSTI)

    Chou, H. S.; Huang, J. C.; Chang, L. W. [Department of Materials and Optoelectronic Science, Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); Nieh, T. G. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States)

    2008-11-10

    Ternary Zr-Cu-Ti system, especial with a high Ti content, is normally difficult to be fully vitrified. In this paper, we demonstrate that cosputtering can produce amorphous Zr-Cu-Ti thin films with an excessive Ti content even as high as 19%. Sub-T{sub g} annealing of the film induces the formation of medium-range-ordered clusters and to raise the nanohardness by 35% to 6.6 GPa. The promising mechanical properties of the sub-T{sub g} annealed Zr{sub 52}Cu{sub 29}Ti{sub 19} films offer great potential for microelectromechanical system applications.

  5. Quantitative phase analysis of Mg:ZrO{sub 2} nanoparticles by Rietveld refinement method

    SciTech Connect (OSTI)

    Balaji, V. Senthilkumaran, S. Thangadurai, P.

    2014-04-24

    To quantify the structural phases of nanocrystalline ZrO{sub 2} doped with Mg ions of varying concentrations (3, 5, 10, 15 and 20%) and annealed at different temperatures. Magnesia doped zirconia was prepared by chemical co-precipitation method and annealed up to 1000°C. The monoclinic and tetragonal phases present in Mg:ZrO{sub 2} were quantified using Rietveld refinement analysis of the X-ray diffraction data and compared with the Direct method based on peak intensity calculations. Tetragonal phase was dominant in the 600°C annealed Mg:ZrO{sub 2} for all Mg concentrations.

  6. Isoscalar Breathing Mode State in Zr-90 and Sn-116 

    E-Print Network [OSTI]

    Rozsa, C. M.; Youngblood, David H.; Bronson, J. D.; Lui, YW; Garg, U.

    1980-01-01

    the AEr gate alone was able to remove essentially all unwanted events, the E' and TOF gates were maintained for additional discrim- ination. Two sets of these gates could be set to collect data in different exit channels. Three 2048 channel position... parameters. Nucleus (MeV) (MeV) W (Me V) t'p (fm) Qp (fm) &c Data angle range ~zr ?6Sn 96 129 45.7 60.8 27.7 40.9 1.50 1.40 0.70 0.73 1.30 1.35 (9'-57') (12'-50') TABLE III. Param. eters of the GMR and GQR. The er- rors...

  7. Pygmy dipole resonance and dipole polarizability in {sup 90}Zr

    SciTech Connect (OSTI)

    Iwamoto, C.; Tamii, A.; Shima, T.; Hashimoto, T.; Suzuki, T.; Fujita, H.; Hatanaka, K. [Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Utsunomiya, H.; Akimune, H.; Yamagata, T.; Okamoto, A.; Kondo, T. [Department of Physics, Konan University, Okamoto 8-9-1, Higashinada, Kobe 658-8501 (Japan); Nakada, H. [Department of Physics, Graduate School of Science, Chiba University, Yayoi-cho 1-33, Inage, Chiba 263-8522 (Japan); Kawabata, T. [Department of Physics, Kyoto University, Kyoto 606-8502 (Japan); Fujita, Y. [Department of Physics, Osaka University, Toyonaka, Osaka, 560-0043 (Japan); Matsubara, H. [RIKEN Nishina Center, Wako, Saitama 351-0198 (Japan); Shimbara, Y.; Nagashima, M. [Department of Physics, Niigata University, Niigata 950-21-2 (Japan); Sakuda, M.; Mori, T. [Department of Physics, Okayama University, Okayama 900-0082 (Japan); and others

    2014-05-02

    Electric dipole (E1) reduced transition probability B(E1) of {sup 90}Zr was obtained by the inelastic proton scattering near 0 degrees using a 295 MeV proton beam and multipole decomposition analysis of the angular distribution by the distorted-wave Born approximation with the Hartree-Fock plus random-phase approximation model and inclusion of El Coulomb excitation, and the E1 strength of the pygmy dipole resonance was found in the vicinity of the neutron threshold in the low-energy tail of the giant dipole resonance. Using the data, we plan to determine the precise dipole polarizability ?{sub D} which is defined as an inversely energy-weighted sum value of the elecrric dipole strength. The dipole polarizability is expected to constrain the symmetry energy term of the neutron matter equation of state. Thus systematical measurement of the dipole polarizability is important.

  8. Performance enhancement of GaN metal–semiconductor–metal ultraviolet photodetectors by insertion of ultrathin interfacial HfO{sub 2} layer

    SciTech Connect (OSTI)

    Kumar, Manoj E-mail: aokyay@ee.bilkent.edu.tr; Tekcan, Burak; Okyay, Ali Kemal E-mail: aokyay@ee.bilkent.edu.tr

    2015-03-15

    The authors demonstrate improved device performance of GaN metal–semiconductor–metal ultraviolet (UV) photodetectors (PDs) by ultrathin HfO{sub 2} (UT-HfO{sub 2}) layer on GaN. The UT-HfO{sub 2} interfacial layer is grown by atomic layer deposition. The dark current of the PDs with UT-HfO{sub 2} is significantly reduced by more than two orders of magnitude compared to those without HfO{sub 2} insertion. The photoresponsivity at 360?nm is as high as 1.42 A/W biased at 5 V. An excellent improvement in the performance of the devices is ascribed to allowed electron injection through UT-HfO{sub 2} on GaN interface under UV illumination, resulting in the photocurrent gain with fast response time.

  9. Low beryllium content Zr-based bulk metallic glass composite with plasticity and work hardenability

    SciTech Connect (OSTI)

    Zheng, Q., E-mail: qiangzheng616@hotmail.com, E-mail: dujuan@nimte.ac.cn [School of Materials Science and Engineering, Ningbo University of Technology, Ningbo, 315016, China and Ningbo Branch of China Academy of Ordnance Science, Ningbo, 315103 (China); Du, J., E-mail: qiangzheng616@hotmail.com, E-mail: dujuan@nimte.ac.cn [Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering (NIMTE), Chinese Academy of Sciences (CAS), Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, NIMTE, CAS, Ningbo 315201 (China)

    2014-01-28

    A modified Zr-based bulk metallic glass matrix composite Zr{sub 47.67}Cu{sub 40}Ti{sub 3.66}Ni{sub 2.66}Be{sub 6} has been produced by increasing the contents of elements of Zr and Cu with higher Poisson ratio and reducing the contents of Ti, Ni, and Be elements with lower Poisson ratio based on famous metallic glass former Vitreloy 1. A compressive yielding strength of 1804?MPa, fracture strength of 1938?MPa and 3.5% plastic strain was obtained for obtained metallic glass composite. Also, work-hardening behavior was observed during compressive experiment which was ascribed to the interaction of the in situ precipitated CuZr phase and shear bands.

  10. Analysis of the electronic structure of ZrO{sub 2} by Compton spectroscopy

    SciTech Connect (OSTI)

    Mahammad, F. M.; Mahammed, S. F. [University of Tikrit 42, Department of Physics (Iraq)] [University of Tikrit 42, Department of Physics (Iraq); Kumar, R.; Vijay, Y. K.; Sharma, B. K. [University of Rajasthan, Department of Physics (India)] [University of Rajasthan, Department of Physics (India); Sharma, G., E-mail: gsphysics@gmail.com [University of Kota, Department of Pure and Applied Physics (India)

    2013-07-15

    The electronic structure of ZrO{sub 2} is studied using the Compton scattering technique. The first-ever Compton profile measurement on polycrystalline ZrO{sub 2} was obtained using 59.54 keV gamma-rays emanating from the {sup 241}Am radioisotope. To explain the experimental data, we compute theoretical Compton profile values using the method of linear combination of atomic orbitals in the framework of density functional theory. The correlation scheme proposed by Perdew-Burke-Ernzerhof and the exchange scheme of Becke are considered. The ionic-model-based calculations for a number of configurations, i.e., Zr{sup +x}(O{sup -x/2}){sub 2} (0 {<=} x {<=} 2), are also performed to estimate the charge transfer on compound formation, and the study supports transfer of 1.5 electrons from Zr to O atoms.

  11. Oxidation induced amorphous stabilization of the subsurface region in Zr-Cu metallic glass

    SciTech Connect (OSTI)

    Lim, K. R. [Light Metal Division, Korea Institute of Materials Science, 797 Changwondaero, Seongsan-gu, Changwon, Gyeongnam 642-831 (Korea, Republic of); Park, J. M. [Materials Research Center, Samsung Advanced Institute of Technology (SAIT) San 14-1, Nongseo-dong, Giheung-gu, Yongin-si, Gyeonggi-do 446-712 (Korea, Republic of); Park, S. H.; Na, M. Y.; Kim, K. C.; Kim, D. H., E-mail: dohkim@yonsei.ac.kr [Department of Materials Science and Engineering, Center for Non-crystalline Materials, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Kim, W. T. [Department of Optical Engineering, Cheongju University, 36 Naedock-dong, Cheongju 360-764 (Korea, Republic of)

    2014-01-20

    In the present study, we demonstrate that selective surface oxidation of Zr{sub 70}Cu{sub 30} metallic glass can stabilize the amorphous structure in the subsurface region of the matrix. The oxidation proceeds by selective oxidation of Zr, forming monoclinic ZrO{sub 2} layer on the surface, and the subsurface layer becomes Cu-enriched due to back diffusion of Cu atoms from the oxide layer. Interestingly, in this system, the composition change in the subsurface region leads to enhancement of glass stability, forming of a double layered surface structure consisted of inner amorphous layer and outer monoclinic ZrO{sub 2} layer even when the remaining matrix is completely crystallized.

  12. The Structural Role of Zr within Alkali Borosilicate Glasses for Nuclear Waste Immobilisation

    SciTech Connect (OSTI)

    A Connelly; N Hyatt; K Travis; R Hand; E Maddrell; R Short

    2011-12-31

    Zirconium is a key constituent element of High Level nuclear Waste (HLW) glasses, occurring both as a fission product and a fuel cladding component. As part of a wider research program aimed at optimizing the solubility of zirconium in HLW glasses, we have investigated the structural chemistry of zirconium in such materials using X-ray Absorption Spectroscopy (XAS). Zirconium K-edge XAS data were acquired from several inactive simulant and simplified waste glass compositions, including a specimen of blended Magnox/UO{sub 2} fuel waste glass. These data demonstrate that zirconium is immobilized as (octahedral) six-fold coordinate ZrO{sub 6} species in these glasses, with a Zr-O contact distance of 2.09 {angstrom}. The next nearest neighbors of the Zr species are Si at 3.42 {angstrom} and possibly Na at 3.44 {angstrom}, no next nearest neighbor Zr could be resolved.

  13. Glass Forming Ability and Relaxation Behavior of Zr Based Metallic Glasses 

    E-Print Network [OSTI]

    Kamath, Aravind Miyar

    2012-07-16

    was studied by using thermal techniques to determine important GFA indicators for Zr-based bulk metallic glasses (BMG). The effect of alloying elements, annealing temperature and annealing time on the thermal and structural relaxation of the BMGs was studied...

  14. Model for Simulation of Hydride Precipitation in Zr-Based Used...

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

    a meso-scale, microstructural evolution model for simulation of zirconium hydride precipitation in the cladding of used fuels during long-term dry-storage. While the Zr-based...

  15. Evolution of ordered {omega} phases in (Zr{sub 3}Al)-Nb alloys

    SciTech Connect (OSTI)

    Tewari, R.; Mukhopadhyay, P.; Banerjee, S.; Bendersky, L.A.

    1999-03-10

    Microstructural investigations on rapidly solidified Zr{sub 3}Al based alloys (binary Zr{sub 3}Al and ternary Zr{sub 3}Al-3Nb and Zr{sub 3}Al-10Nb) have revealed some unusual phase transformation sequences. The Zr{sub 5}Al{sub 3} phase (D8{sub 8} structure) has been found to occur in both the rapidly solidified ternary alloys unlike in the rapidly solidified stoichiometric Zr{sub 3}Al alloy in which the ZrAl phase (B8{sub 2} structure) has been found to be present. The evolution of the D8{sub 8} phase, which could be regarded as one of the ordered derivatives of the {omega} phase, could be described in terms of a superimposition of replacive and displacive ordering waves in the {beta} phase. The orientation relationship between the {beta} and the D8{sub 8} phases has been established. The microstructural changes occurring in the rapidly solidified Zr{sub 3}Al-Nb alloys during aging have been examined. It has been found that on aging the D8{sub 8} phase gets transformed into the B8{sub 2} phase which, on continued aging, transforms to other metastable and equilibrium phases, depending upon the aging temperature. The observed sequence of phase transformations involving different structurally related phases has been along the direction of progressively close packed structures. The symmetry changes associated with the sequence of {omega} related transformations have been summarized in the form of a symmetry tree.

  16. HF-based etching processes for improving laser damage resistance of fused silica optical surfaces

    SciTech Connect (OSTI)

    Suratwala, T I; Miller, P E; Bude, J D; Steele, R A; Shen, N; Monticelli, M V; Feit, M D; Laurence, T A; Norton, M A; Carr, C W; Wong, L L

    2010-02-23

    The effect of various HF-based etching processes on the laser damage resistance of scratched fused silica surfaces has been investigated. Conventionally polished and subsequently scratched fused silica plates were treated by submerging in various HF-based etchants (HF or NH{sub 4}F:HF at various ratios and concentrations) under different process conditions (e.g., agitation frequencies, etch times, rinse conditions, and environmental cleanliness). Subsequently, the laser damage resistance (at 351 or 355 nm) of the treated surface was measured. The laser damage resistance was found to be strongly process dependent and scaled inversely with scratch width. The etching process was optimized to remove or prevent the presence of identified precursors (chemical impurities, fracture surfaces, and silica-based redeposit) known to lead to laser damage initiation. The redeposit precursor was reduced (and hence the damage threshold was increased) by: (1) increasing the SiF{sub 6}{sup 2-} solubility through reduction in the NH4F concentration and impurity cation impurities, and (2) improving the mass transport of reaction product (SiF{sub 6}{sup 2-}) (using high frequency ultrasonic agitation and excessive spray rinsing) away from the etched surface. A 2D finite element crack-etching and rinsing mass transport model (incorporating diffusion and advection) was used to predict reaction product concentration. The predictions are consistent with the experimentally observed process trends. The laser damage thresholds also increased with etched amount (up to {approx}30 {micro}m), which has been attributed to: (1) etching through lateral cracks where there is poor acid penetration, and (2) increasing the crack opening resulting in increased mass transport rates. With the optimized etch process, laser damage resistance increased dramatically; the average threshold fluence for damage initiation for 30 {micro}m wide scratches increased from 7 to 41 J/cm{sup 2}, and the statistical probability of damage initiation at 12 J/cm{sup 2} of an ensemble of scratches decreased from {approx}100 mm{sup -1} of scratch length to {approx}0.001 mm{sup -1}.

  17. Examination Report: OAS-RA-13-01 | Department of Energy

    Office of Environmental Management (EM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirley Ann Jackson About1996 EM HealthCybersecurityExamination Report: OAS-RA-13-01 Examination

  18. Examination Report: OAS-RA-13-02 | Department of Energy

    Office of Environmental Management (EM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirley Ann Jackson About1996 EM HealthCybersecurityExamination Report: OAS-RA-13-01

  19. Audit Report: OAS-RA-L-12-06 | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:FinancingPetroleum Based Fuels Research atDepartmentAudits and6 Audit Report:84 Audit10RA-L-12-06

  20. Inspection Report: INS-RA-12-01 | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankADVANCED MANUFACTURING OFFICE INDUSTRIAL TECHNICAL8-02 Inspection Report: INS-O-98-02 April 2,RA-12-01

  1. Special Report: OAS-RA-10-01 | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX E LIST OF APPLICABLE DIRECTIVESDepartmentSpecial Report: OAS-RA-10-01 Special Report:

  2. Development of a new casting method to fabricate U–Zr alloy containing minor actinides

    SciTech Connect (OSTI)

    Jong Hwan Kim; Hoon Song; Hyung Tae Kim; Ki Hwan Kim; Chan Bock Lee; R. S. Fielding

    2014-01-01

    Metal fuel slugs of U–Zr alloys for a sodium-cooled fast reactor (SFR) have conventionally been fabricated using an injection casting method. However, casting alloys containing volatile radioactive constituents, such as Am, are problematic in a conventional injection casting method. As an alternative fabrication method, low pressure gravity casting has been developed. Casting soundness, microstructural characteristics, alloying composition, density, and fuel losses were evaluated for the following as-cast fuel slugs: U–10 wt% Zr, U–10 wt% Zr–5 wt% RE, and U–10 wt% Zr–5 wt% RE–5 wt% Mn. The U and Zr contents were uniform throughout the matrix, and impurities such as oxyen, carbon, and nitrogen satisfied the specification of total impurities less than 2,000 ppm. The appearance of the fuel slugs was generally sound, and the internal integrity was shown to be satisfactory based on gamma-ray radiography. In a volatile surrogate casting test, the U–Zr–RE–Mn fuel slug showed that nearly all of the manganese was retained when casting was done under an inert atmosphere.

  3. Results from ORNL Characterization of Zr02-500-AK2 - Surrogate TRISO Material

    SciTech Connect (OSTI)

    Hunn, John D [ORNL; Kercher, Andrew K [ORNL

    2005-06-01

    This document is a compilation of the characterization data for the TRISO-coated surrogate particle batch designated ZrO2-500-AK2 that was produced at Oak Ridge National Laboratory (ORNL) as part of the Advanced Gas Reactor Fuel Development and Qualification (AGR) program. The ZrO2-500-AK2 material contains nominally 500 {micro}m kernels of yttria-stabilized zirconia (YSZ) coated with all TRISO layers (buffer, inner pyrocarbon, silicon carbide, and outer pyrocarbon). The ZrO2-500-AK2 material was created for: (1) irradiation testing in the High Flux Isotope Reactor (HFIR) and (2) limited dissemination to laboratories as deemed appropriate to the AGR program. This material was created midway into a TRISO fuel development program to accommodate a sudden opportunity to perform irradiation testing on surrogate material. While the layer deposition processes were chosen based on the best technical understanding at the time, technical progress at ORNL has led to an evolution in the perceived optimal deposition conditions since the createion of ZrO2-500-AK2. Thus, ZrO2-500-AK2 contains a reasonable TRISO microstructure, but does differ significanly from currently produced TRISO surrogates and fuel at ORNL. In this document, characterization data of the ZrO2-500-AK2 surrogate includes: size, shape, coating thickness, and density.

  4. Results from ORNL characterization of ZrO2-500-AK2 - surrogate TRISO material

    SciTech Connect (OSTI)

    Kercher, Andrew K [ORNL; Hunn, John D [ORNL

    2005-06-01

    This document is a compilation of the characterization data for the TRISO-coated surrogate particles designated ZrO2-500-AK2 that was produced at Oak Ridge National Laboratory (ORNL) as part of the Advanced Gas Reactor Fuel Development and Qualification (AGR) program. The ZrO2-500-AK2 material contains nominally 500 {micro}m kernels of yttria-stabilized zirconia (YSZ) coated with all TRISO layers (buffer, inner pyrocarbon, silicon carbide, and outer pyrocarbon). The ZrO2-500-AK2 material was created for: (1) irradiation testing in the High Flux Isotope Reactor (HFIR) and (2) limited dissemination to laboratories as deemed appropriate to the AGR program. This material was created midway into a TRISO fuel development program to accommodate a sudden opportunity to perform irradiation testing on surrogate material. While the layer deposition processes were chosen based on the best technical understanding at the time, technical progress at ORNL has led to an evolution in the perceived optimal deposition conditions since the creation of ZrO2-500-AK2. Thus, ZrO2-500-AK2 contains a reasonable TRISO microstructure, but does differ significantly from currently produced TRISO surrogates and fuel at ORNL. In this document, characterization data of the ZrO2-500-AK2 surrogate includes: size, shape, coating thickness, and density.

  5. Deposition and characterization of TiZrV-Pd thin films by dc magnetron sputtering

    E-Print Network [OSTI]

    Wang, Jie; Xu, Yan-Hui; Wei, Wei; Fan, Le; Pei, Xiang-Tao; Hong, Yuan-Zhi; Wang, Yong

    2015-01-01

    TiZrV film is mainly applied in the ultra-high vacuum pipe of storage ring. Thin film coatings of palladium which was added onto the TiZrV film to increase the service life of nonevaporable getters and enhance pumping speed for H2, was deposited on the inner face of stainless steel pipes by dc magnetron sputtering using argon gas as the sputtering gas. The TiZrV-Pd film properties were investigated by atomic force microscope (AFM), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and X-Ray Diffraction (XRD). The grain size of TiZrV and Pd film were about 0.42~1.3 nm and 8.5~18.25 nm respectively. It was found that the roughness of TiZrV films was small, about 2~4 nm, for Pd film it is large, about 17~19 nm. PP At. % of Pd in TiZrV/Pd films varied from 86.84 to 87.56 according to the XPS test results.

  6. Current-induced spin-orbit torque switching of perpendicularly magnetized Hf|CoFeB|MgO and Hf|CoFeB|TaO{sub x} structures

    SciTech Connect (OSTI)

    Akyol, Mustafa; Yu, Guoqiang; Alzate, Juan G.; Upadhyaya, Pramey; Li, Xiang; Wong, Kin L.; Khalili Amiri, Pedram; Wang, Kang L.; Ekicibil, Ahmet

    2015-04-20

    We study the effect of the oxide layer on current-induced perpendicular magnetization switching properties in Hf|CoFeB|MgO and Hf|CoFeB|TaO{sub x} tri-layers. The studied structures exhibit broken in-plane inversion symmetry due to a wedged CoFeB layer, resulting in a field-like spin-orbit torque (SOT), which can be quantified by a perpendicular (out-of-plane) effective magnetic field. A clear difference in the magnitude of this effective magnetic field (H{sub z}{sup FL}) was observed between these two structures. In particular, while the current-driven deterministic perpendicular magnetic switching was observed at zero magnetic bias field in Hf|CoFeB|MgO, an external magnetic field is necessary to switch the CoFeB layer deterministically in Hf|CoFeB|TaO{sub x}. Based on the experimental results, the SOT magnitude (H{sub z}{sup FL} per current density) in Hf|CoFeB|MgO (?14.12?Oe/10{sup 7} A cm{sup ?2}) was found to be almost 13× larger than that in Hf|CoFeB|TaO{sub x} (?1.05?Oe/10{sup 7} A cm{sup ?2}). The CoFeB thickness dependence of the magnetic switching behavior, and the resulting ?H{sub z}{sup FL} generated by in-plane currents are also investigated in this work.

  7. Comparative Analysis Of {sup 226}Ra Soil-To-Plant Transfer In Cabbage Grown In Various Regions

    SciTech Connect (OSTI)

    Madruga, M. J.; Carvalho, F. P.; Silva, L.; Gouveia, J. [Nuclear and Technological Institute/Department of Radiological Protection and Nuclear Safety E.N. 10, 2686-953 Sacavem (Portugal)

    2008-08-07

    The transfer of {sup 226}Ra from soil to cabbage was compared amongst regions, namely the surroundings of Urgeirica uranium milling tailings (GE), regions with past uranium mining activities (GN1), and regions with no uranium mining activities and no uranium deposits (GN2). Results show a slight increase of the concentration ratio values at low radium concentration in soils. Statistical analysis of the mean {sup 226}Ra activity concentrations in soil and cabbage for the three regions was carried out. The comparison of {sup 226}Ra activity concentrations in soils indicated no difference (p>0.05), between GE and GN2 and significant differences (p<0.05) between GE and GN1 and between GN1 and GN2. Similar statistical results were obtained for {sup 226}Ra activity concentrations in cabbage from the same regions. It was concluded that radium Concentration Ratio (CR) for cabbage grown in the region of the main uranium milling site (GE) is of the same order of magnitude of CR in cabagge grown in background regions (GN2). However, {sup 226}Ra CR was higher in cabagge from the region with past uranium mining activities (GN1)

  8. Rapid Reagentless Detection of M. tuberculosis H37Ra in Respiratory Effluents

    SciTech Connect (OSTI)

    Adams, K L; Steele, P T; Bogan, M J; Sadler, N M; Martin, S; Martin, A N; Frank, M

    2008-01-29

    Two similar mycobacteria, Mycobacteria tuberculosis H37Ra and Mycobacteria smegmatis are rapidly detected and identified within samples containing a complex background of respiratory effluents using Single Particle Aerosol Mass Spectrometry (SPAMS). M. tuberculosis H37Ra (TBa), an avirulent strain, is used as a surrogate for virulent tuberculosis (TBv); M. smegmatis (MSm) is utilized as a near neighbor confounder for TBa. Bovine lung surfactant and human exhaled breath condensate are used as first-order surrogates for infected human lung expirations from patients with pulmonary tuberculosis. This simulated background sputum is mixed with TBa or MSm and nebulized to produce conglomerate aerosol particles, single particles that contain a bacterium embedded within a background respiratory matrix. Mass spectra of single conglomerate particles exhibit ions associated with both respiratory effluents and mycobacteria. Spectral features distinguishing TBa from MSm in pure and conglomerate particles are shown. SPAMS pattern matching alarm algorithms are able to distinguish TBa containing particles from background matrix and MSm for >50% of the test particles, which is sufficient to enable a high probability of detection and a low false alarm rate if an adequate number of such particles are present. These results indicate the potential usefulness of SPAMS for rapid, reagentless tuberculosis screening.

  9. Bio-corrosion and cytotoxicity studies on novel Zr55Co30Ti15 and Cu60Zr20Ti20 metallic glasses

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

    Vincent, S.; Daiwile, A.; Devi, S. S.; Kramer, M. J.; Besser, M. F.; Murty, B. S.; Bhatt, Jatin

    2014-09-26

    Metallic glasses are a potential and compatible implant candidate for biomedical applications. In the present investigation, a comparative study between novel Zr55Co30Ti15 and Cu60Zr20Ti20 metallic glasses is carried out to evaluate in vitro biocompatibility using simulated body fluids. The bio-corrosion behavior of Zr- and Cu-based metallic glasses in different types of artificial body fluids such as artificial saliva solution, phosphate-buffered saline solution, artificial blood plasma solution, and Hank’s balanced saline solution is evaluated using potentiodynamic polarization studies at a constant body temperature of 310.15 K (37 °C). Surface morphology of samples after bio-corrosion experiments was observed by scanning electron microscopy.more »In vitro cytotoxicity test on glassy alloys were performed using human osteosarcoma cell line as per 10993-5 guidelines from International Organization for Standardization. As a result, the comparative study between Zr- and Cu-based glassy alloys provides vital information about the effect of elemental composition on biocompatibility of metallic glasses.« less

  10. Determination of the direct double- ? -decay Q value of Zr 96 and atomic masses of Zr 90 - 92 , 94 , 96 and Mo 92 , 94 - 98 , 100

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

    Gulyuz, K.; Ariche, J.; Bollen, G.; Bustabad, S.; Eibach, M.; Izzo, C.; Novario, S. J.; Redshaw, M.; Ringle, R.; Sandler, R.; et al

    2015-05-06

    Experimental searches for neutrinoless double-? decay offer one of the best opportunities to look for physics beyond the standard model. Detecting this decay would confirm the Majorana nature of the neutrino, and a measurement of its half-life can be used to determine the absolute neutrino mass scale. Important to both tasks is an accurate knowledge of the Q value of the double-? decay. The LEBIT Penning trap mass spectrometer was used for the first direct experimental determination of the ??Zr double-? decay Q value: Q??=3355.85(15) keV. This value is nearly 7 keV larger than the 2012 Atomic Mass Evaluation [M.more »Wang et al., Chin. Phys. C 36, 1603 (2012)] value and one order of magnitude more precise. The 3-? shift is primarily due to a more accurate measurement of the ??Zr atomic mass: m(??Zr)=95.90827735(17) u. Using the new Q value, the 2???-decay matrix element, |M2?|, is calculated. Improved determinations of the atomic masses of all other zirconium (90-92,94,96Zr) and molybdenum (92,94-98,100Mo) isotopes using both ¹²C? and ??Rb as references are also reported.« less

  11. Experimental constraints on the $?$-ray strength function in $^{90}$Zr using partial cross sections of the $^{89}$Y(p,$?$)$^{90}$Zr reaction

    E-Print Network [OSTI]

    L. Netterdon; A. Endres; S. Goriely; J. Mayer; P. Scholz; M. Spieker; A. Zilges

    2015-04-20

    Partial cross sections of the $^{89}$Y(p,$\\gamma$)$^{90}$Zr reaction have been measured to investigate the $\\gamma$-ray strength function in the neutron-magic nucleus $^{90}$Zr. For five proton energies between $E_p=3.65$ MeV and $E_p=4.70$ MeV, partial cross sections for the population of seven discrete states in $^{90}$Zr have been determined by means of in-beam $\\gamma$-ray spectroscopy. Since these $\\gamma$-ray transitions are dominantly of $E1$ character, the present measurement allows an access to the low-lying dipole strength in $^{90}$Zr. A $\\gamma$-ray strength function based on the experimental data could be extracted, which is used to describe the total and partial cross sections of this reaction by Hauser-Feshbach calculations successfully. Significant differences with respect to previously measured strength functions from photoabsorption data point towards deviations from the Brink-Axel hypothesis relating the photo-excitation and de-excitation strength functions.

  12. Ferroelectric performances and crystal structures of (Pb, La)(Zr, Ti, Nb)O{sub 3}

    SciTech Connect (OSTI)

    Kitamura, Naoto [Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan); Division of Ecosystem Research, Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan); Mizoguchi, Takuma [Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan); Itoh, Takanori [AGC Seimi Chemical Co., Ltd., 3-2-10 Chigasaki-City, Kanagawa 253-8585 (Japan); Idemoto, Yasushi, E-mail: idemoto@rs.noda.tus.ac.jp [Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan); Division of Ecosystem Research, Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan)

    2014-02-15

    In this study, we focused on Nb and La substituted Pb(Zr, Ti)O{sub 3}: i.e., (Pb, La)(Zr, Ti, Nb)O{sub 3}. As for the samples, dependences of ferroelectric properties on La and Nb compositions were examined. In addition, the crystal structures were analyzed by the Rietveld method, and then a relationship between the metal compositions and the crystal structures were discussed. From P–E hysteresis loop measurements, it was found that the remanant polarization of Pb(Zr, Ti)O{sub 3} was increased by both the La and Nb substitutions although the heavy substitution of La had an undesirable effect. It was also indicated that the Curie temperature decreased with increasing La content. The Rietveld analysis using synchrotron X-ray diffraction patterns demonstrated that the structure distortion was relaxed by the La and Nb substitutions. Such a change in the crystals was well consistent with the harmful effects on the Curie temperature and the remanent polarization by the heavy La substitution. - Graphical abstract: Rietveld refinement pattern of 2 mol% PbSiO{sub 3}-added Pb{sub 0.95}La{sub 0.05}Zr{sub 0.50}Ti{sub 0.45}Nb{sub 0.05}O{sub 3} (synchrotron X-ray diffraction). Display Omitted - Highlights: • (Pb,La)(Zr,Ti,Nb)O{sub 3} were successfully synthesized. • Remanant polarization of Pb(Zr,Ti)O{sub 3} was improved by substitutions of La and Nb. • Crystal structures of (Pb,La)(Zr,Ti,Nb)O{sub 3} were refined and the distortions were estimated.

  13. Investigation of Interdiffusion Behavior in the Mo-Zr Binary System via Diffusion Couple Studies

    SciTech Connect (OSTI)

    A. Paz y Puente; J. Dickson; D.D. Keiser, Jr.; Y.H. Sohn

    2014-03-01

    Zirconium has recently garnered attention for use as a diffusion barrier between U–Mo metallic nuclear fuels and Al alloy cladding. In order to gain a fundamental understanding of the diffusional interactions, the interdiffusion behavior in the binary Mo–Zr system was investigated via solid-to-solid diffusion couples annealed in the temperature range of 750 to 1050 degrees C. A combination of scanning electron microscopy, X-ray energy dispersive spectroscopy, and electron probe microanalysis were used to examine the microstructure and concentration profiles across the interdiffusion zone. A large __-Zr (cI2) solid solution layer and a thin (approximately 1–2 um) layer of Mo2Zr (cF24) developed in all couples. Parabolic growth constants and concentration dependent interdiffusion coefficients were calculated for the Mo2Zr and Zr solid solution phases, respectively. The pre-exponential factor and activation energy for growth of the Mo2Zr phase were determined to be approximately 6.5 × 10- 15 m2/s and 90 kJ/mol, respectively. The interdiffusion coefficient in ___-Zr solid solution decreased with an increase in Mo concentration. Both the pre-exponential factors (2 × 10- 8 m2/s at 2 at.% Mo to near 5 × 10- 8 m2/s at 9 at.% Mo) and activation energies (140 kJ/mol at 2 at.% Mo to approximately 155 kJ/mol at 9 at.% Mo) of interdiffusion coefficients were determined to increase with an increase in Mo concentration.

  14. The effects of zirconia morphology on methanol synthesis from COand H2 over Cu/ZrO2 catalysts: Part I -- Steady-State Studies

    SciTech Connect (OSTI)

    Rhodes, Michael J.; Bell, Alexis T.

    2005-03-21

    The effect of zirconia phase on the activity and selectivityof Cu/ZrO2 for the hydrogenation of CO has been investigated. Relativelypure t-ZrO2 and m-ZrO2 were prepared with high surface areas (~; 145m2/g). Copper was then deposited onto the surface of these materials byeither incipient-wetness impregnation or deposition-precipitation. For afixed Cu surface area, Cu/m-ZrO2 was tenfold more active for methanolsynthesis than Cu/t-ZrO2 from a feed of 3/1 H2/CO at 3.0 MPa andtemperatures between 473 and 523 K. Cu/m-ZrO2 also exhibited a higherselectivity to methanol. Increasing the Cu surface area on m-ZrO2resulted in further improvement in activity with minimal change inselectivity. Methanol productivity increased linearly for both Cu/t-ZrO2and Cu/m-ZrO2 with increasing Cu surface area. The difference in inherentactivity of each phase paralleled the stronger and larger CO adsorptioncapacity of the Cu/m-ZrO2 as quantified by CO-TPD. The higher COadsorption capacity of Cu/m-ZrO2 is attributed to the presence of a highconcentration of anionic vacancies on the surface of m-ZrO2. Suchvacancies expose cus-Zr4+ cations, which act as Lewis acid centers andenhance the Bronsted acidity of adjacent Zr-OH groups. The presence ofcus-Zr4+ sites and adjacent Bronsted acidic Zr-OH groups contributes tothe adsorption of CO as HCOO-Zr groups, which are the initial precursorsto methanol.

  15. Infrared study on room-temperature atomic layer deposition of HfO{sub 2} using tetrakis(ethylmethylamino)hafnium and remote plasma-excited oxidizing agents

    SciTech Connect (OSTI)

    Kanomata, Kensaku [Graduate School of Science and Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510, Japan and Japan Society for the Promotion of Science, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo 102-0083 (Japan); Ohba, Hisashi; Pungboon Pansila, P.; Ahmmad, Bashir; Kubota, Shigeru; Hirahara, Kazuhiro; Hirose, Fumihiko, E-mail: fhirose@yz.yamagata-u.ac.jp [Graduate School of Science and Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510 (Japan)

    2015-01-01

    Room-temperature atomic layer deposition (ALD) of HfO{sub 2} was examined using tetrakis (ethylmethylamino)hafnium (TEMAH) and remote plasma-excited water and oxygen. A growth rate of 0.26?nm/cycle at room temperature was achieved, and the TEMAH adsorption and its oxidization on HfO{sub 2} were investigated by multiple internal reflection infrared absorption spectroscopy. It was observed that saturated adsorption of TEMAH occurs at exposures of ?1?×?10{sup 5}?L (1 L?=?1?×?10{sup ?6} Torr s) at room temperature, and the use of remote plasma-excited water and oxygen vapor is effective in oxidizing the TEMAH molecules on the HfO{sub 2} surface, to produce OH sites. The infrared study suggested that Hf–OH plays a role as an adsorption site for TEMAH. The reaction mechanism of room temperature HfO{sub 2} ALD is discussed in this paper.

  16. Transfer couplings and hindrance far below the barrier for 40 Ca + 96 Zr

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

    Stefanini, A. M.; Montagnoli, G.; Esbensen, H.; Corradi, L.; Courtin, S.; Fioretto, E.; Goasduff, A.; Grebosz, J.; Haas, F.; Mazzocco, M.; et al

    2015-01-29

    The sub-barrier fusion excitation function of 40Ca + 96Zr has been measured down to cross sections ?2.4µb, i.e. two orders of magnitude smaller than obtained in the previous experiment, where the sub-barrier fusion of this system was found to be greatly enhanced with respect to 40Ca + 90Zr, and the need of coupling to transfer channels was suggested. The purpose of this work was to investigate the behavior of 40Ca + 96Zr fusion far below the barrier. The smooth trend of the excitation function has been found to continue, and the logarithmic slope increases very slowly. No indication of hindrancemore »shows up, and a comparison with 48Ca + 96Zr is very useful in this respect. A new CC analysis of the complete excitation function has been performed, including explicitly one- and two-nucleon Q >0 transfer channels. Such transfer couplings bring significant cross section enhancements, even at the level of a few µb. Locating the hindrance threshold, if any, in 40Ca + 96Zr would require challenging measurements of cross sections in the sub-µb range.« less

  17. Melting temperatures of the ZrO{sub 2}-MOX system

    SciTech Connect (OSTI)

    Uchida, T.; Hirooka, S.; Kato, M.; Morimoto, K.; Sugata, H.; Shibata, K.; Sato, D.

    2013-07-01

    Severe accidents occurred at the Fukushima Daiichi Nuclear Power Plant Units 1-3 on March 11, 2011. MOX fuels were loaded in the Unit 3. For the thermal analysis of the severe accident, melting temperature and phase state of MOX corium were investigated. The simulated coriums were prepared from 4%Pu-containing MOX, 8%Pu-containing MOX and ZrO{sub 2}. Then X-ray diffraction, density and melting temperature measurements were carried out as a function of zirconium and plutonium contents. The cubic phase was observed in the 25%Zr-containing corium and the tetragonal phase was observed in the 50% and 75%Zr-containing coria. The lattice parameter and density monotonically changed with Pu content. Melting temperature increased with increasing Pu content; melting temperature were estimated to be 2932 K for 4%Pu MOX corium and 3012 K for 8%Pu MOX corium in the 25%ZrO{sub 2}-MOX system. The lowest melting temperature was observed for 50%Zr-containing corium. (authors)

  18. The Long Wavelength Array (LWA): A Large HF/VHF Array for Solar Physics, Ionospheric Science, and Solar Radar

    E-Print Network [OSTI]

    Ellingson, Steven W.

    be an excellent receiver for solar radar, potentially demonstrating accurate geomagnetic storm prediction fromThe Long Wavelength Array (LWA): A Large HF/VHF Array for Solar Physics, Ionospheric Science, and Solar Radar A Ground-Based Instrument Paper for the 2010 NRC Decadal Survey of Solar and Space

  19. The Long Wavelength Array (LWA): A Large HF/VHF Array for Solar Physics, Ionospheric Science, and Solar Radar

    E-Print Network [OSTI]

    Ellingson, Steven W.

    construction in New Mexico, and discuss the scientific goals of the project in the areas of solar, ionosphericThe Long Wavelength Array (LWA): A Large HF/VHF Array for Solar Physics, Ionospheric Science, and Solar Radar Namir E. Kassim Naval Research Laboratory, Washington, DC 20375 Stephen M. White AFRL

  20. PHYSICAL REVIEW C 83, 067303 (2011) Deformation and its influence on K isomerism in neutron-rich Hf nuclei

    E-Print Network [OSTI]

    Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University

    2011-01-01

    around N = 116, using configuration-constrained calculations of potential-energy surfaces. Despite having energy (2.4 MeV) in the isomer has been associated with proposals for a clean reservoir of nuclear energy reduced shape elongation, the multiquasiparticle states in 186,188 Hf remain moderately robust against

  1. Role of hydrogen in Ge/HfO2/Al gate stacks subjected to negative bias temperature instability

    E-Print Network [OSTI]

    Misra, Durgamadhab "Durga"

    Role of hydrogen in Ge/HfO2/Al gate stacks subjected to negative bias temperature instability N 2007; published online 17 January 2008 This work investigates the role of hydrogen and nitrogen in a Ge. Virtually unchanged interface state density as a function of NBTI indicates no atomic hydrogen release from

  2. Computational investigation of the phase stability and the electronic properties for Gd-doped HfO{sub 2}

    SciTech Connect (OSTI)

    Wang, L. G. [General Research Institute for Nonferrous Metals, Beijing 100088 (China); California Institute of Technology, Pasadena, California 91125 (United States); Xiong, Y.; Xiao, W.; Cheng, L.; Du, J.; Tu, H. [General Research Institute for Nonferrous Metals, Beijing 100088 (China); Walle, A. van de [Brown University, Providence, Rhode Island 02912 (United States); California Institute of Technology, Pasadena, California 91125 (United States)

    2014-05-19

    Rare earth doping is an important approach to improve the desired properties of high-k gate dielectric oxides. We have carried out a comprehensive theoretical investigation on the phase stability, band gap, formation of oxygen vacancies, and dielectric properties for the Gd-doped HfO{sub 2}. Our calculated results indicate that the tetragonal phase is more stable than the monoclinic phase when the Gd doping concentration is greater than 15.5%, which is in a good agreement with the experimental observations. The dopant's geometric effect is mainly responsible for the phase stability. The Gd doping enlarges the band gap of the material. The dielectric constant for the Gd-doped HfO{sub 2} is in the range of 20–30 that is suitable for high-k dielectric applications. The neutral oxygen vacancy formation energy is 3.2?eV lower in the doped material than in pure HfO{sub 2}. We explain the experimental observation on the decrease of photoluminescence intensities in the Gd-doped HfO{sub 2} according to forming the dopant-oxygen vacancy complexes.

  3. Analytical Potential Energy Surface for the Na + HF NaF + H reaction: Application of Conventional Transition-State Theory

    E-Print Network [OSTI]

    Analytical Potential Energy Surface for the Na + HF NaF + H reaction: Application of Conventional Transition-State Theory Alessandra F. A. Vilela, Ricardo Gargano a Patr´icia R.P. Barreto b a Instituto de from calculation of the rate constant using con- ventional Transition State Theory (TST

  4. PII S0016-7037(00)00369-0 Ra isotopes and Rn in brines and ground waters of the Jordan-Dead Sea Rift Valley

    E-Print Network [OSTI]

    Yehoshua, Kolodny

    , yet enrichment in water sources is most often not associated with anomalously high uranium or thorium Rift Valley: Enrichment, retardation, and mixing TAMAR MOISE, ABRAHAM STARINSKY, AMITAI KATZ surrounding rocks into the brine end member. 228 Ra/226 Ra ratios are exceptionally low 0.07 to 0.9, mostly

  5. Remarkable Strontium B-Site Occupancy in Ferroelectric Pb(Zr1-xTix)O3 Solid Solutions Doped with Cryolite-Type Strontium Niobate

    E-Print Network [OSTI]

    Feltz, A.; Schmidt-Winkel, P.; Schossman, M.; Booth, C.H.; Albering, J.

    2007-01-01

    contains Lead-Titanium-Zirconium Oxide of Specificstructure such as lead zirconium titanium oxide Pb(Zr,Ti)O 3

  6. Irradiation-Enhanced Second-Phase Precipitation in Zr-Fe Nanocrystalline Thin Films , A. T. Motta1

    E-Print Network [OSTI]

    Motta, Arthur T.

    Irradiation-Enhanced Second-Phase Precipitation in Zr-Fe Nanocrystalline Thin Films D. Kaoumi1 , A with Fe. Heat treatment in the absence of irradiation was observed to cause precipitation of the Zr2Fe in the presence of ion irradiation. Samples were irradiated in-situ at the Intermediate Voltage Electron

  7. GALACTIC EVOLUTION OF Sr, Y, AND Zr: A MULTIPLICITY OF NUCLEOSYNTHETIC PROCESSES Claudia Travaglio,1,2

    E-Print Network [OSTI]

    Cowan, John

    GALACTIC EVOLUTION OF Sr, Y, AND Zr: A MULTIPLICITY OF NUCLEOSYNTHETIC PROCESSES Claudia Travaglio versus Eu, an almost pure r-process element. We present a detailed analysis of a large published database and Sr, Y, Zr all had the same r-process nucleosynthetic origin. We discuss our chemical evolution

  8. Aging behavior and precipitates analysis of the CuCrZrCe alloy Yi Zhang a,b,d,n

    E-Print Network [OSTI]

    Volinsky, Alex A.

    Aging behavior and precipitates analysis of the Cu­Cr­Zr­Ce alloy Yi Zhang a,b,d,n , Alex A October 2015 Keywords: Cu­Cr­Zr­Ce alloy Cold rolling Aging treatment Microstructure Physical properties rolling and aging for 16 h at 300 °C. Under the same aging conditions, without cold rolling, the hardness

  9. Local laser induced rapid thermal oxidation of SOI substrates , R.A. Deutschmann, R. Neumann, K. Brunner, G. Abstreiter

    E-Print Network [OSTI]

    Deutschmann, Rainer

    Local laser induced rapid thermal oxidation of SOI substrates M. Huber* , R.A. Deutschmann, R by a focused laser beam. By focusing the cw light of an argon ion laser at a wavelength of 458 nm (514 nm) we achieve a diffraction limited laser spot of 315 nm (350 nm). The laser spot is scanned over the surface

  10. www.sciencesignaling.org/cgi/content/full/6/263/ra12/DC1 Supplementary Materials for

    E-Print Network [OSTI]

    Higgins, Darren

    .P.); perrimon@receptor.med.harvard.edu (N.P.) Published 19 February 2013, Sci. Signal. 6, ra12 (2013) DOI: 10 (blue). Purple line indicates zone 2 defined on the basis of its position at the junction of TC and SB at the junction with the transverse connective (TC) and in the spiracular abdominal histoblasts (SAH). (B) cut

  11. For assistance contact your Contract Administrator or the eRA Help Desk (5-6263). Office of Research Administration

    E-Print Network [OSTI]

    Hill, Wendell T.

    For assistance contact your Contract Administrator or the eRA Help Desk (5-6263). Office of Research Administration University of Maryland, College Park Fiscal Year 2015 Quick Reference Guide Administrator (http://ora.umd.edu/staff). Complete the Internal Routing Form http://ora.umd.edu/forms/umd Obtain

  12. Microfluidics for block polymer shells (DMR 0819860) SEED :H.A. Stone, R.A. Register and Janine Nunes

    E-Print Network [OSTI]

    Petta, Jason

    Microfluidics for block polymer shells (DMR 0819860) SEED :H.A. Stone, R.A. Register and Janine. We utilized microfluidic methods to investigate the role of geometric structures, e.g. thin spherical, microfluidic devices with two consecutive flow-focusing junctions were used to generate air bubble

  13. PRECIPITATION The images above use daily precipitation statistics from NWS COOP, CoCoRaHS, and

    E-Print Network [OSTI]

    Collett Jr., Jeffrey L.

    PRECIPITATION The images above use daily precipitation statistics from NWS COOP, CoCoRaHS, and CoAgMet stations. From top to bottom, and left to right: most recent 7-days of accumulated precipitation in inches; current month-to-date accumulated precipitation in inches; last month's precipitation as a percent

  14. Photocatalytic studies of Ho–Zr–O nano-composite with controllable composition and defects

    SciTech Connect (OSTI)

    Du, Weimin, E-mail: duweimin75@gmail.com [College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, Henan 455000 (China); Zhao, Guoyan; Chang, Hongxun; Shi, Fei; Zhu, Zhaoqiang [College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, Henan 455000 (China); Qian, Xuefeng [School of Chemistry and Chemical Technology, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2013-09-15

    With the help of sol–gel method assisted by melting salt, a series of Ho–Zr–O nano-composite with controllable composition and defects have been successfully prepared. Characterization results show that the positions, intensity, and width of the X-ray diffraction peaks of the products have a regular variation with the increase of zirconium element which implies the gradual changes of crystal spacing and product size. At the same time, the molar ratios between holmium and zirconium ions are consistent with the chemical formula and both of them are uniformly distributed in products further showing the perfect formation of targeted materials. Optical properties reveal that diversified defect forms of Ho–Zr–O nano-composite lead to the different absorptions of visible light. Photocatalytic experiments demonstrate Zr{sub 0.8}Ho{sub 0.2}O{sub 2??} nano-crystals have excellent visible-light-responsive photocatalytic activities on some familiar dyes (e.g.: methylene blue and Rhodamine B) which results from the special defect structure, better absorption of visible light and larger specific surface area. It follows that Zr{sub 0.8}Ho{sub 0.2}O{sub 2??} nano-crystals are a new kind of visible-light-responsive photocatalysts with better prospects in conversion and utilization of solar energy. Also, the present melting salt assisted route might be generalized to synthesize other AxByOz composite oxide nano-crystals with more complicated structures. - Highlights: • Ho–Zr–O nano-composite with controllable composition and defects has been obtained. • Diversified defect forms of products lead to the different visible light absorption. • Zr{sub 0.8}Ho{sub 0.2}O{sub 2??} nano-crystals have excellent photocatalytic activities.

  15. Band alignment between GaN and ZrO{sub 2} formed by atomic layer deposition

    SciTech Connect (OSTI)

    Ye, Gang; Wang, Hong, E-mail: ewanghong@ntu.edu.sg; Arulkumaran, Subramaniam; Ng, Geok Ing; Li, Yang; Ang, Kian Siong [Novitas, Nanoelectronics Center of Excellence, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Liu, Zhi Hong [Singapore-MIT Alliance for Research and Technology, 1 CREATE Way, Singapore 138602 (Singapore)

    2014-07-14

    The band alignment between Ga-face GaN and atomic-layer-deposited ZrO{sub 2} was investigated using X-ray photoelectron spectroscopy (XPS). The dependence of Ga 3d and Zr 3d core-level positions on the take-off angles indicated upward band bending at GaN surface and potential gradient in ZrO{sub 2} layer. Based on angle-resolved XPS measurements combined with numerical calculations, valence band discontinuity ?E{sub V} of 1?±?0.2?eV and conduction band discontinuity ?E{sub C} of 1.2?±?0.2?eV at ZrO{sub 2}/GaN interface were determined by taking GaN surface band bending and potential gradient in ZrO{sub 2} layer into account.

  16. Search for spin-orbit-force reduction at {sup 106,108}Zr around r-process path

    SciTech Connect (OSTI)

    Sumikama, T.; Yoshinaga, K. [Department of Physics, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan); Watanabe, H. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); and others

    2012-11-12

    Shell gap at the magic number N= 82 is important to reproduce the 2nd peak of r-process abundance. If a spin-orbit force is reduced in a very neutron-rich region, a shell quenching at N= 82 and a new shell closure at N70 are predicted. A shell evolution by the spin-orbit-force reduction can be searched for through the shape evolution of Zr isotopes around an expected double magic nuclei, {sup 110}Zr(Z = 40,N = 70). We performed {beta}-{gamma} and isomer spectroscopy at RIBF to observe low-lying states in {sup 106,108}Zr. The present results indicate a well deformed shape for {sup 106,108}Zr. The drastic reduction of the spin-orbit force most likely does not occur around {sup 110}Zr on an r-process path.

  17. Ab-initio study of high temperature lattice dynamics of BCC zirconium (?-Zr) and uranium (?-U)

    SciTech Connect (OSTI)

    Ghosh, Partha S., E-mail: parthasarathi13@gmail.com; Arya, A., E-mail: parthasarathi13@gmail.com; Dey, G. K., E-mail: parthasarathi13@gmail.com [Materials Science Division, Bhabha Atomic Research Centre, Mumbai-400085 (India)

    2014-04-24

    Using self consistent ab-initio lattice dynamics calculations, we show that bcc structures of Zr and U phases become stable at high temperature by phonon-phonon interactions. The calculated temperature dependent phonon dispersion curve (PDC) of ?-Zr match excellently with experimental PDC. But the calculated PDC for ?-U shows negative phonon frequencies even at solid to liquid transition temperature. We show that this discrepancy is due to an overestimation of instability depth of bcc U phase which is removed by incorporation of spin-orbit coupling in the electronic structure calculations.

  18. Obtaining composite Zr-Al-O coating on the surface of zirconium by microplasma oxidation

    SciTech Connect (OSTI)

    Gubaidulina, Tatiana A. E-mail: ostk@mail2000ru; Kuzmin, Oleg S. E-mail: ostk@mail2000ru; Fedorischva, Marina V. E-mail: kmp1980@mail.ru; Kalashnikov, Mark P. E-mail: kmp1980@mail.ru; Sergeev, Viktor P.

    2014-11-14

    The paper describes the application of the microplasma oxidation for production of Zr-Al-O composition on the surface of zirconium. Certification of a new-type power supply for depositing oxide ceramic coatings by microplasma oxidation was also carried out. The growth rate of Zr-Al-O coating amounted around 0.2 nm/s, which around 10 times exceeds that for depositing similar coatings using the similar equipment. We have studied the change of surface morphology and the chemical composition of the formed ceramic coating by means of EVO 50 scanning electron microscope and X-ray spectral analysis.

  19. InfoEd eRA Portal is maintained by the UConn Office of the Vice President for Research. For technical issues with the eRA system please email eRA-help@uconn.edu, call 860-486-7944, or visit http://training.research.uconn.edu.

    E-Print Network [OSTI]

    Alpay, S. Pamir

    InfoEd® eRA Portal is maintained by the UConn Office of the Vice President for Research functions within the InfoEd portal. The Web VPN service works best with Internet Explorer for Windows an agreement with InfoEd. Connect Via the Web 1. Go to http://sslvpn.uconn.edu/. 2. The UConn Web VPN Portal

  20. Am phases in the matrix of a U–Pu–Zr alloy with Np, Am, and rare-earth elements

    SciTech Connect (OSTI)

    Janney, Dawn E.; Kennedy, J. Rory; Madden, James W.; O’Holleran, Thomas P.

    2015-01-01

    Phases and microstructures in the matrix of an as-cast U-Pu-Zr alloy with 3 wt% Am, 2% Np, and 8% rare-earth elements were characterized by scanning and transmission electron microscopy. The matrix consists primarily of two phases, both of which contain Am: ?-(U, Np, Pu, Am) (~70 at% U, 5% Np, 14% Pu, 1% Am, and 10% Zr) and ?-(U, Np, Pu, Am)Zr2 (~25% U, 2% Np, 10-15% Pu, 1-2% Am, and 55-60 at% Zr). These phases are similar to those in U-Pu-Zr alloys, although the Zr content in ?-(U, Np, Pu, Am) is higher than that in ?-(U, Pu) and the Zr content in ?-(U, Np, Pu, Am)Zr2 is lower than that in ?-UZr2. Nanocrystalline actinide oxides with structures similar to UO2 occurred in some areas, but may have formed by reactions with the atmosphere during sample handling. Planar features consisting of a central zone of ?-(U, Np, Pu, Am) bracketed by zones of ?-(U, Np, Pu, Am)Zr2 bound irregular polygons ranging in size from a few micrometers to a few tens of micrometers across. The rest of the matrix consists of elongated domains of ?-(U, Np, Pu, Am) and ?-(U, Np, Pu, Am)Zr2. Each of these domains is a few tens of nanometers across and a few hundred nanometers long. The domains display strong preferred orientations involving areas a few hundred nanometers to a few micrometers across.

  1. Total ionizing dose effect of ?-ray radiation on the switching characteristics and filament stability of HfOx resistive random access memory

    SciTech Connect (OSTI)

    Fang, Runchen; Yu, Shimeng; Gonzalez Velo, Yago; Chen, Wenhao; Holbert, Keith E.; Kozicki, Michael N.; Barnaby, Hugh

    2014-05-05

    The total ionizing dose (TID) effect of gamma-ray (?-ray) irradiation on HfOx based resistive random access memory was investigated by electrical and material characterizations. The memory states can sustain TID level ?5.2 Mrad (HfO{sub 2}) without significant change in the functionality or the switching characteristics under pulse cycling. However, the stability of the filament is weakened after irradiation as memory states are more vulnerable to flipping under the electrical stress. X-ray photoelectron spectroscopy was performed to ascertain the physical mechanism of the stability degradation, which is attributed to the Hf-O bond breaking by the high-energy ?-ray exposure.

  2. Transmission electron microscopy examination of oxide layers formed on Zr alloys

    E-Print Network [OSTI]

    Motta, Arthur T.

    Transmission electron microscopy examination of oxide layers formed on Zr alloys Aylin Yilmazbayhan, United States Received 14 July 2005; accepted 31 October 2005 Abstract A transmission electron microscopy. In this work, cross-sectional transmission electron microscopy was used to determine the morphology

  3. Phase Stability and Thermodynamic Assessment of the Np-Zr system 

    E-Print Network [OSTI]

    Bajaj, Saurabh

    2012-02-14

    of minor actinides and fission products on phase stability. Within this framework, we present a study on phase equilibria in the binary Np-Zr alloy system on which little work has been published. To resolve the contradictory reports on the ordering...

  4. Microfluxgate sensor with amorphous cobalt (Co-Nb-Zr) soft magnetic core for electronic compass

    SciTech Connect (OSTI)

    Na, Kyoung-Won; Yuan, Jingli; Ji, Joon-Ho; Choi, Sang-On [Nano Fabrication Center, Samsung Advanced Institute of Technology (SAIT) (Korea, Republic of); MEMS Laboratory, Samsung Advanced Institute of Technology (SAIT) (Korea, Republic of)

    2006-04-15

    A silicon based microfluxgate sensor with a cobalt based amorphous soft magnetic core for electronic compass is presented in this paper. A sputtered Co{sub 85}Nb{sub 12}Zr{sub 3} magnetic core having a rectangular ring shape is combined with microcopper solenoid coils for excitation and pickup, which were wound alternately around the core to increase the number of coil turns. The Co{sub 85}Nb{sub 12}Zr{sub 3} as a core material is adopted for improving properties of the magnetic core and easy integration with micromachining processes to achieve a small size of the sensor. The sputtered Co{sub 85}Nb{sub 12}Zr{sub 3} showed dc effective permeability of {approx}10 000 and an extremely low coercivity of {approx}0.03 Oe with the thickness of 1 {mu}m. The Co{sub 85}Nb{sub 12}Zr{sub 3} as a thin film core with high permeability and low coercivity was easily saturated by a low excitation magnetic field, enhancing the sensitivity and linearity of the microfluxgate sensor. Finally, the sensor showed excellent linearity response over the range of -300 to 300 {mu}T with sensitivity of 60 V/T at the excitation condition of 3.0 V{sub p-p} and 5.0 MHz square wave form. The sensor size excluding pad region is about 0.55x1.4 mm{sup 2}.

  5. Effect of Niobium on the Defect Chemistry and Oxidation Kinetics of Tetragonal ZrO2

    E-Print Network [OSTI]

    Yildiz, Bilge

    of Nuclear Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge transport limits the oxidation kinetics. 1. INTRODUCTION Zirconia (ZrO2) is among the most important metal-6 Furthermore, zirconia is used in biomedical hip implants7 and dental restorations8 and recently

  6. Effect of the oxide layer on current-induced spin-orbit torques in Hf|CoFeB|MgO and Hf|CoFeB|TaO{sub x} structures

    SciTech Connect (OSTI)

    Akyol, Mustafa; Alzate, Juan G.; Yu, Guoqiang; Upadhyaya, Pramey; Wong, Kin L.; Khalili Amiri, Pedram; Wang, Kang L.; Ekicibil, Ahmet

    2015-01-19

    We study the effect of the oxide layer on the current-induced spin-orbit torques (SOTs) in perpendicularly magnetized Hf|CoFeB|MgO (MgO-capped) or Hf|CoFeB|TaO{sub x} (TaO{sub x}-capped) structures. The effective fields corresponding to both the field-like and damping-like current-induced SOTs are characterized using electric transport measurements. Both torques are found to be significantly stronger in MgO-capped structures than those in TaO{sub x}-capped structures. The difference in field-like and damping-like SOTs in the different structures may be attributed to the different Rashba-like Hamiltonian, arising from the difference in the electric potential profiles across the oxide|ferromagnet interfaces in the two cases, as well as possible structural and oxidation differences in the underlying CoFeB and Hf layers. Our results show that the oxide layer in heavy-metal|ferromagnet|oxide trilayer structures has a very significant effect on the generated SOTs for manipulation of ferromagnetic layers. These findings could potentially be used to engineer SOT devices with enhanced current-induced switching efficiency.

  7. Structural and microstructural changes in monoclinic ZrO{sub 2} during the ball-milling with stainless steel assembly

    SciTech Connect (OSTI)

    Stefanic, G. . E-mail: stefanic@irb.hr; Music, S.; Gajovic, A.

    2006-04-13

    High-energy ball-milling of monoclinic ZrO{sub 2} was performed in air using the planetary ball mill with a stainless steel milling assembly. Structural and microstructural changes during the ball-milling were monitored using X-ray powder diffraction, Raman spectroscopy, Moessbauer spectroscopy, field emission scanning electron microscopy and energy dispersive X-ray spectrometry. The results of line broadening analysis indicated a decrease in the crystallite size and an increase in the microstrains with the ball-milling time increased up to {approx}150 min. The results of quantitative phase analysis indicated the presence of a very small amount of tetragonal ZrO{sub 2} phase in this early stage of ball-milling. The onset of m-ZrO{sub 2} {sup {yields}} t-ZrO{sub 2} transition occurred between 10 and 15 h of ball-milling, which resulted in a complete transition after 20 h of ball-milling. Further ball-milling caused a decrease of the t-ZrO{sub 2} lattice parameters followed by a probable transition into c-ZrO{sub 2}. It was concluded that the stabilization of t- and c-ZrO{sub 2} polymorphs at RT can be attributed to the incorporation of aliovalent cations (Fe{sup 2+}, Fe{sup 3+} and Cr{sup 3+}) introduced into the sample due to the wear and oxidation of the milling media.

  8. Morphology and chemical termination of HF-etched Si{sub 3}N{sub 4} surfaces

    SciTech Connect (OSTI)

    Liu, Li-Hong; Debenedetti, William J. I.; Peixoto, Tatiana; Gokalp, Sumeyra; Shafiq, Natis; Veyan, Jean-François; Chabal, Yves J.; Michalak, David J.; Hourani, Rami

    2014-12-29

    Several reports on the chemical termination of silicon nitride films after HF etching, an important process in the microelectronics industry, are inconsistent claiming N-H{sub x}, Si-H, or fluorine termination. An investigation combining infrared and x-ray photoelectron spectroscopies with atomic force and scanning electron microscopy imaging reveals that under some processing conditions, salt microcrystals are formed and stabilized on the surface, resulting from products of Si{sub 3}N{sub 4} etching. Rinsing in deionized water immediately after HF etching for at least 30?s avoids such deposition and yields a smooth surface without evidence of Si-H termination. Instead, fluorine and oxygen are found to terminate a sizeable fraction of the surface in the form of Si-F and possibly Si-OH bonds. The relatively unique fluorine termination is remarkably stable in both air and water and could lead to further chemical functionalization pathways.

  9. Composition and grain size effects on the structural and mechanical properties of CuZr nanoglasses

    SciTech Connect (OSTI)

    Adibi, Sara [Institute of High Performance Computing, A*STAR, 138632 Singapore (Singapore); Mechanical Engineering Department, National University of Singapore, 117576 Singapore (Singapore); Branicio, Paulo S., E-mail: branicio@ihpc.a-star.edu.sg; Zhang, Yong-Wei [Institute of High Performance Computing, A*STAR, 138632 Singapore (Singapore); Joshi, Shailendra P., E-mail: Shailendra@nus.edu.sg [Mechanical Engineering Department, National University of Singapore, 117576 Singapore (Singapore)

    2014-07-28

    Nanoglasses (NGs), metallic glasses (MGs) with a nanoscale grain structure, have the potential to considerably increase the ductility of traditional MGs while retaining their outstanding mechanical properties. We investigated the effects of composition on the structural and mechanical properties of CuZr NG films with grain sizes between 3 to 15?nm using molecular dynamics simulations. Results indicate a transition from localized shear banding to homogeneous superplastic flow with decreasing grain size, although the critical average grain size depends on composition: 5?nm for Cu{sub 36}Zr{sub 64} and 3?nm for Cu{sub 64}Zr{sub 36}. The flow stress of the superplastic NG at different compositions follows the trend of the yield stress of the parent MG, i.e., Cu{sub 36}Zr{sub 64} yield/flow stress: 2.54?GPa/1.29?GPa and Cu{sub 64}Zr{sub 36} yield/flow stress: 3.57?GPa /1.58?GPa. Structural analysis indicates that the differences in mechanical behavior as a function of composition are rooted at the distinct statistics of prominent atomic Voronoi polyhedra. The mechanical behavior of NGs is also affected by the grain boundary thickness and the fraction of atoms at interfaces for a given average grain size. The results suggest that the composition dependence of the mechanical behavior of NGs follows that of their parent MGs, e.g., a stronger MG will generate a stronger NG, while the intrinsic tendency for homogeneous deformation occurring at small grain size is not affected by composition.

  10. Glass formation in binary and ternary Zr based Fe and Ni bearing alloys

    SciTech Connect (OSTI)

    Savalia, R.T.; Tewari, R.; Banerjee, S.; Dey, G.K.

    1996-01-01

    Rapid solidification of the Zr{sub 76}Fe{sub 24-x}Ni{sub x} alloys (x - 0, 4, 8, 12, 16, 20 and 24) by melt spinning under different conditions has yielded fully amorphous as well as partially crystalline ribbons. The partially crystalline ribbons have been found to contain crystal aggregates comprising a core of the {beta}-Zr phase surrounded by peripheral crystals of the Zr{sub 3}(Fe,Ni) phase in alloys with x < 12. In alloys containing larger amount of Ni (x {ge} 12), both Zr{sub 2}Ni and Zr{sub 3}(Fe,Ni) crystals have been found to be present in the periphery. The nucleation of the core crystals and the peripheral crystals in the undercooled melt has been examined by considering transient and steady state homogeneous and heterogeneous nucleation. The transient nucleation time and the steady state nucleation rate of crystals have been evaluated. For this purpose, use has been made of molar free energy difference {Delta}G{sub c} between the liquid and the crystalline phases determined from experimentally evaluated quantities. The growth of the crystals in the undercooled melt has been examined taking into account recalescence and heat removal during melt spinning. The glass forming ability of the alloys has been evaluated on the basis of the avoidance of crystallization approach. A comparison has been made between the microstructures of the splat cooled and the melt spun alloys in order to understand the process of solidification and the nature of phase transformation during post solidification cooling.

  11. Proton-induced cross sections relevant to production of 225Ac and 223Ra in natural thorium targets below 200 MeV

    E-Print Network [OSTI]

    J. W. Weidner; S. G. Mashnik; K. D. John; F. Hemez; B. Ballard; H. Bach; E. R. Birnbaum; L. J. Bitteker; A. Couture; D. Dry; M. E. Fassbender; M. S. Gulley; K. R. Jackman; J. L. Ullmann; L. E. Wolfsberg; F. M. Nortier

    2012-05-15

    Cross sections for 223,225Ra, 225Ac and 227Th production by the proton bombardment of natural thorium targets were measured at proton energies below 200 MeV. Our measurements are in good agreement with previously published data and offer a complete excitation function for 223,225Ra in the energy range above 90 MeV. Comparison of theoretical predictions with the experimental data shows reasonable-to-good agreement. Results indicate that accelerator-based production of 225Ac and 223Ra below 200 MeV is a viable production method.

  12. Calculations of the cross sections for the neutron acceleration, slowing down, and capture by the isomer "OmHf

    E-Print Network [OSTI]

    Shlyakhter, Ilya

    Calculations of the cross sections for the neutron acceleration, slowing down, and capture for the isomer lsomHf in the energy range of the incoming neutron from 1keV to 5 MeV. Below 0.7 MeV the energy transferred to the neutron in the collision is positive on the average, i.e., the isomer is acting

  13. Report of the ICFA Beam Dynamics Workshop 'Accelerators for a Higgs Factory: Linear vs. Circular' (HF2012)

    E-Print Network [OSTI]

    Alain Blondel; Alex Chao; Weiren Chou; Jie Gao; Daniel Schulte; Kaoru Yokoya

    2013-02-15

    This paper is a summary report of the ICFA Beam Dynamics Workshop 'Accelerators for a Higgs Factory: Linear vs. Circular' (HF2012). It discusses four types of accelerators as possible candidates for a Higgs factory: linear e+e- colliders, circular e+e- colliders, muon collider and photon colliders. The comparison includes: physics reach, performance (energy and luminosity), upgrade potential, technology maturity and readiness, and technical challenges requiring further R&D.

  14. Structure and properties of nanocrystalline ZrN{sub x}O{sub y} thin films: Effect of the oxygen content and film thickness

    SciTech Connect (OSTI)

    Lan, Kuan-Che; Hunag, Jia-Hong; Ai, Chi-Fong; Yu, Ge-Ping [Department of Engineering and System Science, National Tsing Hua University, 101 Kuang Fu Rd., Sec. 2, Hsinchu, 300 Taiwan (China); Institute of Nuclear Energy Research, Atomic Energy Council, Taoyuan, 325 Taiwan (China); Department of Engineering and System Science, National Tsing Hua University, 101 Kuang Fu Rd., Sec. 2, Hsinchu, 300 Taiwan (China) and Institute of Nuclear Engineering and Science, 101 Kuang Fu Rd., Sec. 2, Hsinchu, 300 Taiwan (China)

    2011-05-15

    The main objective of this study was to investigate the structure and properties of ZrN{sub x}O{sub y} thin films associated with oxygen content and film thickness. ZrN{sub x}O{sub y} thin films were deposited using hollow cathode discharge ion plating on Si (100) substrate. The thickness of ZrN{sub x}O{sub y} films increased with increasing oxygen flow rate, ranging from 143 to 894 nm. Phase separation from ZrN{sub x}O{sub y} to ZrN and monoclinic ZrO{sub 2} (m-ZrO{sub 2}) was observed by x-ray diffraction (XRD). The electrical and mechanical properties were influenced by the film thickness and the amount of separated phase, m-ZrO{sub 2}. ZrN{sub x}O{sub y} thin films with smaller thickness or deposited at higher O{sub 2} flow rate were found to have higher electrical resistivity. Hardness of the ZrN{sub x}O{sub y} thin films increased with increasing thickness, which could be related to microstructure change of the thin films. Residual stress of the ZrN phase in the ZrN{sub x}O{sub y} thin films, measured using the modified sin{sup 2} {psi} XRD method, decreased with increasing oxygen flow rate. The thickness dependence of the residual stress in ZrN was different with different oxygen flow rates. The average residual stress of the ZrN{sub x}O{sub y} thin films also decreased with increasing oxygen flow rate and the stress did not showed significant dependence on the film thickness.

  15. Effect of Zr on microstructures and mechanical properties of an Al-Mg-Si-Cu-Cr alloy prepared by low frequency electromagnetic casting

    SciTech Connect (OSTI)

    Meng, Yi, E-mail: yimonmy@sina.com; Cui, Jianzhong; Zhao, Zhihao; He, Lizi

    2014-06-01

    The Al-1.6Mg-1.2Si-1.1Cu-0.15Cr (all in wt. %) alloys with and without Zr addition prepared by low frequency electromagnetic casting process were investigated by using the optical microscope, scanning electron microscope and transmission electron microscope equipped with energy dispersive analytical X-ray. The effects of Al{sub 3}Zr phases on the microstructures and mechanical properties during solidification, homogenization, hot extrusion and solid solution were studied. The results show that Al{sub 3}Zr phases reduce the grain size by ? 29% and promote the formation of an equiaxed grain structure during solidification. Numerous spherical Al{sub 3}Zr dispersoids with 35–60 nm in diameters precipitate during homogenization, and these fine dispersoids change little during subsequent hot extrusion and solid solution. Adding 0.15 wt. % Zr results in no recrystallization after hot extrusion and partial recrystallization after solid solution, while the recrystallized grain size is 400–550 ?m in extrusion direction in the Zr-free alloy. In addition, adding 0.15 wt. % Zr can obviously promote Q? phase precipitation, while the ?? phases are predominant in the alloy without Zr. Adding 0.15 wt. % Zr, the ultimate tensile strength of the T6 treated alloy increases by 45 MPa, while the elongation remains about 16.7%. - Highlights: • Minor Zr can refine as-cast grains of the LFEC Al-Mg-Si-Cu-Cr alloy. • L1{sub 2} Al{sub 3}Zr phases with 35–60 nm in diameter precipitate during homogenization. • L1{sub 2} and DO{sub 22} Al{sub 3}Zr phases result in partial recrystallization after solid solution. • Minor Zr can promote the precipitation of Q? phases. • Mechanical properties of Al-Mg-Si-Cu-Cr-Zr alloy are higher than those of AA7005.

  16. N-body simulations of oligarchic growth of Mars: Implications for Hf-W chronology

    E-Print Network [OSTI]

    Morishima, Ryuji; Samuel, Henri

    2013-01-01

    Dauphas and Pourmand (2011) [Nature 473, 489--492] estimated the accretion timescale of Mars to be 1.8 $^{+0.9}_{-1.0}$ Myr from the W isotopes of martian meteorites. This timescale was derived assuming perfect metal-silicate equilibration between the impactor and the target's mantle. However, in the case of a small impactor most likely only a fraction of the target's mantle is involved in the equilibration, while only a small part of the impactor's core equilibrates in the case of a giant impact. We examined the effects of imperfect equilibration using results of high-resolution $N$-body simulations for the oligarchic growth stage. These effects were found to be small as long as a planetary embryo has a deep liquid magma ocean during its accretion. The effect due to partial involvement of the target's mantle in equilibration is small due to the low metal-silicate partition coefficient for W suggested from the low Hf/W ratio of the martian mantle. The effect due to partial involvement of the impactor's core i...

  17. Temperature dependent structural, optical and hydrophobic properties of sputtered deposited HfO{sub 2} films

    SciTech Connect (OSTI)

    Dave, V. [Department of Electrical Engineering, IIT Roorkee (India); Institute Instrumentation Centre, IIT Roorkee (India); Dubey, P.; Chandra, R. [Institute Instrumentation Centre, IIT Roorkee (India); Gupta, H. O. [Department of Electrical Engineering, IIT Roorkee (India)

    2014-01-28

    Hafnium oxide being high-k dielectric has been successfully utilized in electronic and optical applications. Being thermodynamically stable and having good mechanical strength, it can be used as a protective coating for outdoor HV insulators which are suffering from surface flashover problem due to contamination. In this paper, we are investigating the effect of substrate temperature on structural, optical and hydrophobic properties of hafnium oxide coating deposited over glass insulators by DC magnetron sputtering. X-ray diffraction is applied to determine the crystalline phase and crystallite size of the film. The morphology of the samples is examined using atomic force microscopy. The optical properties are studied using UV-vis-NIR spectrophotometer. The wettability of the film is investigated using contact angle meter. The thickness is measured using surface profilometer and verified through optical data. The relationship between substrate temperature with grain size, roughness, refractive index, and hydrophobicity is manifested. The maximum contact angle for HfO{sub 2} film was found to be 106° at 400°C.

  18. Experiments and theory on parametric instabilities excited in HF heating experiments at HAARP

    SciTech Connect (OSTI)

    Kuo, Spencer; Snyder, Arnold; Lee, M. C.

    2014-06-15

    Parametric instabilities excited by O-mode HF heater and the induced ionospheric modification were explored via HAARP digisonde operated in a fast mode. The impact of excited Langmuir waves and upper hybrid waves on the ionosphere are manifested by bumps in the virtual spread, which expand the ionogram echoes upward as much as 140?km and the downward range spread of the sounding echoes, which exceeds 50?km over a significant frequency range. The theory of parametric instabilities is presented. The theory identifies the ionogram bump located between the 3.2?MHz heater frequency and the upper hybrid resonance frequency and the bump below the upper hybrid resonance frequency to be associated with the Langmuir and upper hybrid instabilities, respectively. The Langmuir bump is located close to the upper hybrid resonance frequency, rather than to the heater frequency, consistent with the theory. Each bump in the virtual height spread of the ionogram is similar to the cusp occurring in daytime ionograms at the E-F2 layer transition, indicating that there is a small ledge in the density profile similar to E-F2 layer transitions. The experimental results also show that the strong impact of the upper hybrid instability on the ionosphere can suppress the Langmuir instability.

  19. The Concentrations of {sup 40}K, {sup 226}Ra and {sup 232}Th in Soil Sample in Osmaniye (Turkey)

    SciTech Connect (OSTI)

    Akkurt, I.; Guenoglu, K.; Kara, A.; Mavi, B.; Karaboerklue, S.

    2011-12-26

    The {sup 40}K, {sup 226}Ra and {sup 232}Th concentration is due to the magmatic structure of the earth and it can be varied from place to place. Osmaniye is located in the Eastern side of Mediteranean Region. It holds the climatic characteristics of the same region and arises with Middle Taurus Mountains from west to North and with Amonos Mounations in East and West-east parts and is situated between 35 deg. .52'-36 deg. .42' east longitudes and 36 deg. .57'-37 deg. .45' north latitudes. In this study, the natural radioactivity concentrations {sup 40}K, {sup 226}Ra and {sup 232}Th in some soil samples collected in Osmaniye have been investigated. The measurements have been performed using 3x3{sup ''} NaI(Tl) detector system.

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

    SciTech Connect (OSTI)

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

    2014-12-15

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

  1. Effects of Support Composition and Pretreatment Conditions on the Structure of Vanadia Dispersed on SiO2, Al2O3, TiO2, ZrO2, and HfO2

    E-Print Network [OSTI]

    Iglesia, Enrique

    , including the selective reduction of NOx with ammonia and the oxidative dehydroge- nation of alkanes.1-visible) were utilized to monitor the effect of adsorbed water, calcination temperature, and reduction in H2 a phase transition from tetragonal to monoclinic. H2 reduction produced limited changes in the structure

  2. Stellar 30-keV neutron capture in 94,96Zr and the 90Zr(gamma,n)89Zr photonuclear reaction with a high-power liquid-lithium target

    E-Print Network [OSTI]

    Tessler, M; Arenshtam, A; Feinberg, G; Friedman, M; Halfon, S; Kijel, D; Weissman, L; Aviv, O; Berkovits, D; Eisen, Y; Eliyahu, I; Haquin, G; Kreisel, A; Mardor, I; Shimel, G; Shor, A; Silverman, I; Yungrais, Z

    2015-01-01

    A high-power Liquid-Lithium Target (LiLiT) was used for the first time for neutron production via the thick-target 7Li(p,n)7Be reaction and quantitative determination of neutron capture cross sections. Bombarded with a 1-2 mA proton beam at 1.92 MeV from the Soreq Applied Research Accelerator Facility (SARAF), the setup yields a 30-keV quasi-Maxwellian neutron spectrum with an intensity of 3-5e10 n/s, more than one order of magnitude larger than present near-threshold 7Li(p,n) neutron sources. The setup was used here to determine the 30-keV Maxwellian averaged cross section (MACS) of 94Zr and 96Zr as 28.0+-0.6 mb and 12.4+-0.5 mb respectively, based on activation measurements. The precision of the cross section determinations results both from the high neutron yield and from detailed simulations of the entire experimental setup. We plan to extend our experimental studies to low-abundance and radioactive targets. In addition, we show here that the setup yields intense high-energy (17.6 and 14.6 MeV) prompt cap...

  3. Hardness variation and cyclic crystalline-amorphous phase transformation in CuZr alloy during ball milling

    E-Print Network [OSTI]

    Schoen, David Taylor

    2005-01-01

    The hardness and percent crystallinity of Cu33Zr67 powder samples are measured through several cycles of a cyclic phase transformation during ball milling. Each are found to cycle with a period of approximately 320 minutes. ...

  4. Charge-trapping characteristics of fluorinated thin ZrO{sub 2} film for nonvolatile memory applications

    SciTech Connect (OSTI)

    Huang, X. D., E-mail: eexdhuang@gmail.com, E-mail: laip@eee.hku.hk [Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 210096 (China); Shi, R. P.; Lai, P. T., E-mail: eexdhuang@gmail.com, E-mail: laip@eee.hku.hk [Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong (China)

    2014-04-21

    The effects of fluorine treatment on the charge-trapping characteristics of thin ZrO{sub 2} film are investigated by physical and electrical characterization techniques. The formation of silicate interlayer at the ZrO{sub 2}/SiO{sub 2} interface is effectively suppressed by fluorine passivation. However, excessive fluorine diffusion into the Si substrate deteriorates the quality of the SiO{sub 2}/Si interface. Compared with the ZrO{sub 2}-based memory devices with no or excessive fluorine treatment, the one with suitable fluorine-treatment time shows higher operating speed and better retention due to less resistance of built-in electric field (formed by trapped electrons) against electron injection from the substrate and smaller trap-assisted tunneling leakage, resulting from improved ZrO{sub 2}/SiO{sub 2} and SiO{sub 2}/Si interfaces.

  5. Reactive sputtering of ?-ZrH{sub 2} thin films by high power impulse magnetron sputtering and direct current magnetron sputtering

    SciTech Connect (OSTI)

    Högberg, Hans Tengdelius, Lina; Eriksson, Fredrik; Broitman, Esteban; Lu, Jun; Jensen, Jens; Hultman, Lars; Samuelsson, Mattias

    2014-07-01

    Reactive sputtering by high power impulse magnetron sputtering (HiPIMS) and direct current magnetron sputtering (DCMS) of a Zr target in Ar/H{sub 2} plasmas was employed to deposit Zr-H films on Si(100) substrates, and with H content up to 61 at.?% and O contents typically below 0.2 at.?% as determined by elastic recoil detection analysis. X-ray photoelectron spectroscopy reveals a chemical shift of ?0.7?eV to higher binding energies for the Zr-H films compared to pure Zr films, consistent with a charge transfer from Zr to H in a zirconium hydride. X-ray diffraction shows that the films are single-phase ?-ZrH{sub 2} (CaF{sub 2} type structure) at H content >?55 at.?% and pole figure measurements give a 111 preferred orientation for these films. Scanning electron microscopy cross-section images show a glasslike microstructure for the HiPIMS films, while the DCMS films are columnar. Nanoindentation yield hardness values of 5.5–7 GPa for the ?-ZrH{sub 2} films that is slightly harder than the ?5 GPa determined for Zr films and with coefficients of friction in the range of 0.12–0.18 to compare with the range of 0.4–0.6 obtained for Zr films. Wear resistance testing show that phase-pure ?-ZrH{sub 2} films deposited by HiPIMS exhibit up to 50 times lower wear rate compared to those containing a secondary Zr phase. Four-point probe measurements give resistivity values in the range of ?100–120 ?? cm for the ?-ZrH{sub 2} films, which is slightly higher compared to Zr films with values in the range 70–80 ?? cm.

  6. Thermal behavior of the amorphous precursors of the ZrO{sub 2}-SnO{sub 2} system

    SciTech Connect (OSTI)

    Stefanic, Goran Music, Svetozar; Ivanda, Mile

    2008-11-03

    Thermal behavior of the amorphous precursors of the ZrO{sub 2}-SnO{sub 2} system on the ZrO{sub 2}-rich side of the concentration range, prepared by co-precipitation from aqueous solutions of the corresponding salts, was monitored using differential thermal analysis, X-ray powder diffraction, Raman spectroscopy, field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectrometry (EDS). The crystallization temperature of the amorphous precursors increased with an increase in the SnO{sub 2} content, from 405 deg. C (0 mol% SnO{sub 2}) to 500 deg. C (40 mol% SnO{sub 2}). Maximum solubility of Sn{sup 4+} ions in the ZrO{sub 2} lattice ({approx}25 mol%) occurred in the metastable products obtained upon crystallization of the amorphous precursors. A precise determination of unit-cell parameters, using both Rietveld and Le Bail refinements of the powder diffraction patterns, shows that the incorporation of Sn{sup 4+} ions causes an asymmetric distortion of the monoclinic ZrO{sub 2} lattice. The results of phase analysis indicate that the incorporation of Sn{sup 4+} ions has no influence on the stabilization of cubic ZrO{sub 2} and negligible influence on the stabilization of tetragonal ZrO{sub 2}. Partial stabilization of tetragonal ZrO{sub 2} in products having a tin content above its solid-solubility limit was attributed to the influence of ZrO{sub 2}-SnO{sub 2} surface interactions. In addition to phases closely structurally related to cassiterite, monoclinic ZrO{sub 2} and tetragonal ZrO{sub 2}, a small amount of metastable ZrSnO{sub 4} phase appeared in the crystallization products of samples with 40 and 50 mol% of SnO{sub 2} calcined at 1000 deg. C. Further temperature treatments caused a decrease in and disappearance of metastable phases. The results of the micro-structural analysis show that the sinterability of the crystallization products significantly decreases with an increase in the SnO{sub 2} content.

  7. Features of an intermetallic n-ZrNiSn semiconductor heavily doped with atoms of rare-earth metals

    SciTech Connect (OSTI)

    Romaka, V. A., E-mail: vromaka@polynet.lviv.ua [National Academy of Sciences of Ukraine, Ya. Pidstryhach Institute for Applied Problems of Mechanics and Mathematics (Ukraine); Fruchart, D.; Hlil, E. K. [CNRS, Institute Neel (France); Gladyshevskii, R. E. [Ivan Franko Lviv National University (Ukraine); Gignoux, D. [CNRS, Institute Neel (France); Romaka, V. V.; Kuzhel, B. S. [Ivan Franko Lviv National University (Ukraine); Krayjvskii, R. V. [Lvivska Politechnika National University (Ukraine)

    2010-03-15

    The crystal structure, density of electron states, electron transport, and magnetic characteristics of an intermetallic n-ZrNiSn semiconductor heavily doped with atoms of rare-earth metals (R) have been studied in the ranges of temperatures 1.5-400 K, concentrations of rare-earth metal 9.5 x 10{sup 19}-9.5 x 10{sup 21} cm{sup -3}, and magnetic fields H {<=} 15 T. The regions of existence of Zr{sub 1-x}R{sub x}NiSn solid solutions are determined, criteria for solubility of atoms of rare-earth metals in ZrNiSn and for the insulator-metal transition are formulated, and the nature of 'a priori doping' of ZrNiSn is determined as a result of redistribution of Zr and Ni atoms at the crystallographic sites of Zr. Correlation between the concentration of the R impurity, the amplitude of modulation of the bands of continuous energies, and the degree of occupation of potential wells of small-scale fluctuations with charge carriers is established. The results are discussed in the context of the Shklovskii-Efros model of a heavily doped and compensated semiconductor.

  8. The photoluminescence properties of Er{sup 3+}-doped ZrO{sub 2} nanotube arrays prepared by anodization

    SciTech Connect (OSTI)

    Wang, Xixin; Zhao, Jianling; Du, Peng; Guo, Limin; Xu, Xuewen; Tang, Chengchun

    2012-11-15

    Graphical abstract: Display Omitted Highlights: ? Er{sup 3+}-doped ZrO{sub 2} nanotube arrays were prepared by anodization of Zr–Er alloy. ? Small tetragonal zirconia crystallites are tended to be formed due to the doping of Er{sup 3+}. ? Under excitation at 317 nm, the ZrO{sub 2} nantube arrays have strongest photoluminescence intensity. -- Abstract: Er{sup 3+}-doped ZrO{sub 2} nanotube arrays were prepared by anodization of Zr–Er alloy which was obtained by melting zirconium with 1.0 wt% erbium. The morphology, structure and photoluminescence properties were studied through scanning electron microscope, transmission electron microscope, X-ray diffraction and photoluminescence analyzer. X-ray diffraction results indicate that doping of Er{sup 3+} affects the crystal structure and grain size obviously and the Er{sup 3+}-doped samples tend to form small tetragonal grains. Photoluminescence analyses show that when Er{sup 3+}-doped zirconia nanotube arrays are excited at 317 nm, there are two strong photoluminescence emission peaks at 373 nm and 415 nm. When the excitation wavelength is 257 nm, a photoluminescence emission peak appears at 363 nm. Under same measurement conditions, emission peaks of the undoped ZrO{sub 2} nanotube arrays are very weak.

  9. Devitrification kinetics and phase selection mechanisms in Cu-Zr metallic glasses

    SciTech Connect (OSTI)

    Kalay, Ilkay

    2010-12-15

    Metallic glasses have been a promising class of materials since their discovery in the 1960s. Indeed, remarkable chemical, mechanical and physical properties have attracted considerable attention, and several excellent reviews are available. Moreover, the special group of glass forming alloys known as the bulk metallic glasses (BMG) become amorphous solids even at relatively low cooling rates, allowing them to be cast in large cross sections, opening the scope of potential applications to include bulk forms and net shape structural applications. Recent studies have been reported for new bulk metallic glasses produced with lower cooling rates, from 0.1 to several hundred K/s. Some of the application products of BMGs include sporting goods, high performance springs and medical devices. Several rapid solidification techniques, including melt-spinning, atomization and surface melting have been developed to produce amorphous alloys. The aim of all these methods is to solidify the liquid phase rapidly enough to suppress the nucleation and growth of crystalline phases. Furthermore, the production of amorphous/crystalline composite (ACC) materials by partial crystallization of amorphous precursor has recently given rise to materials that provide better mechanical and magnetic properties than the monolithic amorphous or crystalline alloys. In addition, these advances illustrate the broad untapped potential of using the glassy state as an intermediate stage in the processing of new materials and nanostructures. These advances underlie the necessity of investigations on prediction and control of phase stability and microstructural dynamics during both solidification and devitrification processes. This research presented in this dissertation is mainly focused on Cu-Zr and Cu-Zr-Al alloy systems. The Cu-Zr binary system has high glass forming ability in a wide compositional range (35-70 at.% Cu). Thereby, Cu-Zr based alloys have attracted much attention according to fundamental research on the behaviors of glass forming alloys. Further motivation arising from the application of this system as a basis for many BMGs and ACC materials; the Cu-Zr system warrants this attention and offers great potential for the development of new materials. However, the prediction and control of microstructural evolution during devitrification remains challenging because of the complex devitrification behavior of the Cu-Zr binary alloy which is arising from the competition of metastable and stable phases and diversity of crystal structures. This dissertation details a systematic fundamental investigation into the mechanisms and kinetics of the various crystallization transformation processes involved in the overall devitrification response of Cu-Zr and Cu-Zr-Al glasses. Various isothermal and nonisothermal treatments are employed, and the structural response is characterized using bulk X-ray and thermal analysis methods as well as nanoscale microscopic analysis methods, revealing structural and chemical details down to the atomic-scale. By carefully combining techniques such as differential scanning calorimetry (DSC), in-situ synchrotron high energy X-ray diffraction (HEXRD), and transmission electron microscopy (TEM) to quantify the characterization transformations, this research has uncovered numerous details concerning the atomistic mechanisms of crystallization and has provided much new understanding related to the dominant phases, the overall reaction sequences, and the rate-controlling mechanisms. As such this work represents a substantial step forward in understanding these transformations and provides a clear framework for further progress toward ultimate application of controlled devitrification processing for the production of new materials with remarkable properties.

  10. Permeability of CoNbZr amorphous thin films over a wide frequency range

    SciTech Connect (OSTI)

    Koyama, H.; Tsujimoto, H.; Shirae, K.

    1987-09-01

    CoNbZr amorphous films have attracted the attention of many researchers because of their high saturation magnetization, high permeability, low coercivity, and nearly zero magnetostriction. For these films to be used, one of the important magnetic properties is the behavior of the permeability over a wide frequency range. We have measured the permeability of a square-shaped magnetic film (13 mm x 55 mm) sputtered on a glass substrate from 1 MHz to 400 MHz using a stripline. Over 400 MHz, the permeability of the magnetic film was measured using a ring-shaped sample mounted in a coaxial fixture. The wall motion permeability of CoNbZr amorphous films decreases from 1 kHz to nearly zero at 1 MHz. The rotation permeability is constant to 100 MHz and ferromagnetic resonance is observed near 1 GHz.

  11. Separate effects identification via casting process modeling for experimental measurement of U–Pu–Zr alloys

    SciTech Connect (OSTI)

    J. Crapps; D. S. DeCroix; J. D. Galloway; D. A. Korzekwa; R. Aikin; R. Fielding; R. Kennedy; C. Unal

    2013-11-01

    Computational simulations of gravity casting processes for metallic U–Pu–Zr nuclear fuel rods have been performed using a design-of-experiments technique to determine the fluid flow, liquid heat transfer, and solid heat transfer parameters which most strongly influence the process solidification speed and fuel rod porosity. The results are used to make recommendations for the best investment of experimental time and effort to measure process parameters.

  12. Irradiation Induced Precipitation and Dissolution of Intermetallics in Zr Alloys Studied Using Synchrotron Radiation

    SciTech Connect (OSTI)

    Arthur T. Motta

    2004-09-21

    The overall aim of this project is to investigate the irradiation induced precipitation of alloying elements and dissolution of second phase particles in Zr alloys using a combination of (1) synchrotron radiation examination of bulk samples using the Advanced Photon Source (APS) at Argonne National Laboratory and (2) in-situ irradiation of model alloys using the IVEM/Tandem Facility also located at Argonne

  13. A Novel Zr-1Nb Alloy and a New Look at Hydriding

    SciTech Connect (OSTI)

    Robert D. Mariani; James I. Cole; Assel Aitkaliyeva

    2013-09-01

    A novel Zr-1Nb has begun development based on a working model that takes into account the hydrogen permeabilities for zirconium and niobium metals. The beta-Nb secondary phase particles (SPPs) in Zr-1Nb are believed to promote more rapid hydrogen dynamics in the alloy in comparison to other zirconium alloys. Furthermore, some hydrogen release is expected at the lower temperatures corresponding to outages when the partial pressure of H2 in the coolant is less. These characteristics lessen the negative synergism between corrosion and hydriding that is otherwise observed in cladding alloys without niobium. In accord with the working model, development of nanoscale precursors was initiated to enhance the performance of existing Zr-1Nb alloys. Their characteristics and properties can be compared to oxide-dispersion strengthened alloys, and material additions have been proposed to zirconium-based LWR cladding to guard further against hydriding and to fix the size of the SPPs for microstructure stability enhancements. A preparative route is being investigated that does not require mechanical alloying, and 10 nanometer molybdenum particles have been prepared which are part of the nanoscale precursors. If successful, the approach has implications for long term dry storage of used fuel and for new routes to nanoferritic and ODS alloys.

  14. Thickness independent reduced forming voltage in oxygen engineered HfO{sub 2} based resistive switching memories

    SciTech Connect (OSTI)

    Sharath, S. U. Kurian, J.; Komissinskiy, P.; Hildebrandt, E.; Alff, L.; Bertaud, T.; Walczyk, C.; Calka, P.; Schroeder, T.

    2014-08-18

    The conducting filament forming voltage of stoichiometric hafnium oxide based resistive switching layers increases linearly with layer thickness. Using strongly reduced oxygen deficient hafnium oxide thin films grown on polycrystalline TiN/Si(001) substrates, the thickness dependence of the forming voltage is strongly suppressed. Instead, an almost constant forming voltage of about 3?V is observed up to 200?nm layer thickness. This effect suggests that filament formation and switching occurs for all samples in an oxidized HfO{sub 2} surface layer of a few nanometer thickness while the highly oxygen deficient thin film itself merely serves as a oxygen vacancy reservoir.

  15. Controlled oxygen vacancy induced p-type conductivity in HfO{sub 2-x} thin films

    SciTech Connect (OSTI)

    Hildebrandt, Erwin; Kurian, Jose; Mueller, Mathis M.; Kleebe, Hans-Joachim; Alff, Lambert [Institute of Materials Science, Technische Universitaet Darmstadt, 64287 Darmstadt (Germany); Schroeder, Thomas [IHP, 15236 Frankfurt/Oder (Germany)

    2011-09-12

    We have synthesized highly oxygen deficient HfO{sub 2-x} thin films by controlled oxygen engineering using reactive molecular beam epitaxy. Above a threshold value of oxygen vacancies, p-type conductivity sets in with up to 6 times 10{sup 21} charge carriers per cm{sup 3}. At the same time, the band-gap is reduced continuously by more than 1 eV. We suggest an oxygen vacancy induced p-type defect band as origin of the observed behavior.

  16. Physical properties and band structure of reactive molecular beam epitaxy grown oxygen engineered HfO{sub 2{+-}x}

    SciTech Connect (OSTI)

    Hildebrandt, Erwin; Kurian, Jose; Alff, Lambert [Institute of Materials Science, Technische Universitaet Darmstadt, 64287 Darmstadt (Germany)

    2012-12-01

    We have conducted a detailed thin film growth structure of oxygen engineered monoclinic HfO{sub 2{+-}x} grown by reactive molecular beam epitaxy. The oxidation conditions induce a switching between (111) and (002) texture of hafnium oxide. The band gap of oxygen deficient hafnia decreases with increasing amount of oxygen vacancies by more than 1 eV. For high oxygen vacancy concentrations, defect bands form inside the band gap that induce optical transitions and p-type conductivity. The resistivity changes by several orders of magnitude as a function of oxidation conditions. Oxygen vacancies do not give rise to ferromagnetic behavior.

  17. Room temperature strain rate sensitivity in precursor derived HfO{sub 2}/Si-C-N(O) ceramic nanocomposites

    SciTech Connect (OSTI)

    Sujith, Ravindran; Kumar, Ravi

    2014-01-15

    Investigation on the room temperature strain rate sensitivity using depth sensing nanoindentation is carried out on precursor derived HfO{sub 2}/Si-C-N(O) ceramic nanocomposite sintered using pulsed electric current sintering. Using constant load method the strain rate sensitivity values are estimated. Lower strain rate sensitivity of ? 3.7 × 10{sup ?3} is observed and the limited strain rate sensitivity of these ceramic nanocomposites is explained in terms of cluster model. It is concluded that presence of amorphous Si-C-N(O) clusters are responsible for the limited flowability in these ceramics.

  18. : 8GM-I=8=!"pJsCj=P!"%3!%Q%9Hf3S Analysis on Difficulty Indices

    E-Print Network [OSTI]

    : 8GM-I=8=!"¿pJsCj=P!"%3!¡%Q%9Hf3S Analysis on Difficulty Indices for Japanese Named Entity comparison 1 $O$8$a$K K"8&5f$NL"E*$O!"¿pJsCj=P$N%5%V%?%9%/$G$"$k8GM-I=8=Cj=(Named Entity Task) $NFq0WEY $N$N%o!¡%/%7%g%C%WMessage Understanding Conference (MUC) $G%?%9%/$NDj5A!&I¿2A$,9T$o$l$F$-$?!#8GM-I=8=(Named

  19. Energy band alignment of atomic layer deposited HfO{sub 2} on epitaxial (110)Ge grown by molecular beam epitaxy

    SciTech Connect (OSTI)

    Hudait, M. K.; Zhu, Y. [Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States)] [Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States); Maurya, D.; Priya, S. [Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech, Blacksburg, Virginia 24061 (United States)] [Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech, Blacksburg, Virginia 24061 (United States)

    2013-03-04

    The band alignment properties of atomic layer HfO{sub 2} film deposited on epitaxial (110)Ge, grown by molecular beam epitaxy, was investigated using x-ray photoelectron spectroscopy. The cross-sectional transmission electron microscopy exhibited a sharp interface between the (110)Ge epilayer and the HfO{sub 2} film. The measured valence band offset value of HfO{sub 2} relative to (110)Ge was 2.28 {+-} 0.05 eV. The extracted conduction band offset value was 2.66 {+-} 0.1 eV using the bandgaps of HfO{sub 2} of 5.61 eV and Ge bandgap of 0.67 eV. These band offset parameters and the interface chemical properties of HfO{sub 2}/(110)Ge system are of tremendous importance for the design of future high hole mobility and low-power Ge-based metal-oxide transistor devices.

  20. Photo-induced tunneling currents in MOS structures with various HfO{sub 2}/SiO{sub 2} stacking dielectrics

    SciTech Connect (OSTI)

    Pang, Chin-Sheng; Hwu, Jenn-Gwo

    2014-04-15

    In this study, the current conduction mechanisms of structures with tandem high-k dielectric in illumination are discussed. Samples of Al/SiO{sub 2}/Si (S), Al/HfO{sub 2}/SiO{sub 2}/Si (H), and Al/3HfO{sub 2}/SiO{sub 2}/Si (3H) were examined. The significant observation of electron traps of sample H compares to sample S is found under the double bias capacitance-voltage (C-V) measurements in illumination. Moreover, the photo absorption sensitivity of sample H is higher than S due to the formation of HfO{sub 2} dielectric layer, which leads to larger numbers of carriers crowded through the sweep of V{sub G} before the domination of tunneling current. Additionally, the HfO{sub 2} dielectric layer would block the electrons passing through oxide from valance band, which would result in less electron-hole (e{sup ?}-h{sup +}) pairs recombination effect. Also, it was found that both of the samples S and H show perimeter dependency of positive bias currents due to strong fringing field effect in dark and illumination; while sample 3H shows area dependency of positive bias currents in strong illumination. The non-uniform tunneling current through thin dielectric and through HfO{sub 2} stacking layers are importance to MOS(p) tunneling photo diodes.

  1. Investigation of Zr-doped BSCF perovskite membrane for oxygen separation in the intermediate temperature range

    SciTech Connect (OSTI)

    Ravkina, Olga; Klande, Tobias; Feldhoff, Armin

    2013-05-01

    The series of (Ba?.?Sr?.?)(Co?.?Fe?.?){sub 1–z}Zr{sub z}O{sub 3–?} (z=0, 0.01, 0.03, 0.05, 0.07, and 0.09) was synthesized by a sol–gel method. The materials with a zirconium content up to 3 mol% were found to be single phase. Further increase results in formation of a mixed (Ba,Sr)ZrO? by-phase, which was found along the grain boundaries and in the grains. With increasing zirconium content the oxygen permeation flux decreases considerably. The effect of the zirconium substitution on the long-term phase stability was investigated by long-term oxygen permeation experiments and X-ray diffraction. A slight stabilization of the oxygen flux of (Ba?.?Sr{sub 0.5})(Co?.?Fe?.?)?.??Zr?.??O{sub 3–?} was found after 180 h at 1023 K. However, all compositions show a decrease in permeation flux with time, but the pure BSCF membrane exhibited the strongest drop after 180 h of operation. The decomposition products of the cubic perovskite phase were found to be a hexagonal Ba{sub 0.5±x}Sr{sub 0.5±x}CoO? and a rhombohedral Ba{sub 1–x}Sr{sub x}Co{sub 2–y}Fe{sub y}O{sub 5–?}. - Graphical abstract: Backscattered-electron channeling contrast image of BSCF membrane cross-section after long-term oxygen permeation at 1023 K showing different phases in different colors. Highlights: • Ba?.?Sr?.?Co?.?Fe?.?O{sub 3–?} systematically doped with increasing amount of zirconium. • Cubic single-phase materials up to 3 wt% zirconium. • Mixed (Ba,Sr)ZrO? by-phase formed mainly in the grain boundaries. • Jänecke prism was proposed by XRD and EDXS data. • (Ba?.?Sr?.?)(Co?.?Fe?.?)?.??Zr?.??O{sub 3–?} showed a slight stabilization of oxygen flux as compared to pure Ba?.?Sr?.?Co?.?Fe?.?O{sub 3–?}.

  2. Self-organization during growth of ZrN/SiN{sub x} multilayers by epitaxial lateral overgrowth

    SciTech Connect (OSTI)

    Fallqvist, A.; Fager, H.; Hultman, L.; Persson, P. O. Å.; Ghafoor, N.

    2013-12-14

    ZrN/SiN{sub x} nanoscale multilayers were deposited on ZrN seed layers grown on top of MgO(001) substrates by dc magnetron sputtering with a constant ZrN thickness of 40 Å and with an intended SiN{sub x} thickness of 2, 4, 6, 8, and 15 Å at a substrate temperature of 800 °C and 6 Å at 500 °C. The films were investigated by X-ray diffraction, high-resolution scanning transmission electron microscopy, and energy dispersive X-ray spectroscopy. The investigations show that the SiN{sub x} is amorphous and that the ZrN layers are crystalline. Growth of epitaxial cubic SiN{sub x}—known to take place on TiN(001)—on ZrN(001) is excluded to the monolayer resolution of this study. During the course of SiN{sub x} deposition, the material segregates to form surface precipitates in discontinuous layers for SiN{sub x} thicknesses ?6 Å that coalesce into continuous layers for 8 and 15 Å thickness at 800 °C, and for 6 Å at 500 °C. The SiN{sub x} precipitates are aligned vertically. The ZrN layers in turn grow by epitaxial lateral overgrowth on the discontinuous SiN{sub x} in samples deposited at 800 °C with up to 6 Å thick SiN{sub x} layers. Effectively a self-organized nanostructure can be grown consisting of strings of 1–3 nm large SiN{sub x} precipitates along apparent column boundaries in the epitaxial ZrN.

  3. RE/ZrO{sub 2} (RE = Sm, Eu) composite oxide nano-materials: Synthesis and applications in photocatalysis

    SciTech Connect (OSTI)

    Du, Weimin, E-mail: duweimin75@gmail.com [College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, Henan 455002 (China); Zhu, Zhaoqiang [College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, Henan 455002 (China); College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou, Henan 450001 (China); Zhang, Xiaofen; Wang, Dacheng; Liu, Donghe [College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, Henan 455002 (China); Qian, Xuefeng [School of Chemistry and Chemical Technology, Shanghai Jiao Tong University, Shanghai 200240 (China); Du, Jimin, E-mail: djm@aynu.edu.cn [College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, Henan 455002 (China)

    2013-10-15

    Graphical abstract: - Highlights: • RE/ZrO{sub 2} (RE = Sm, Eu) nano-materials have been successfully synthesized. • Defect and electron structures determine the absorption properties on visible light. • Nano-sized Zr{sub 0.8}Sm{sub 0.2}O{sub 2??} has good visible-light-responsive photocatalytic activities. • In the future, it can be used in wastewater treatment and environmental protection. - Abstract: Zirconia modified by Samarium/Europium, RE/ZrO{sub 2} (RE = Sm, Eu), composite oxide nano-materials have been successfully synthesized by improved sol–gel method. Characterization results show that X-ray diffraction (XRD) peaks of products gradually shift to the lower angle with the increase of rare earth which implies that the lattice distances of RE/ZrO{sub 2} nano-materials are gradually enlarged. Moreover, the molar ratios between zirconium and rare earth are consistent with the chemical formula and both of them are uniformly distributed in samples. Optical properties indicate that defect structures and electron configurations of RE/ZrO{sub 2} (RE = Sm, Eu) with single phase determine their absorption properties on visible light. Photocatalytic experiments indicate Zr{sub 0.8}Sm{sub 0.2}O{sub 2??} nano-crystals have excellent visible-light-responsive photocatalytic activities on Methylene blue and Rhodamine B which results from the special defect structure, suitable electronic configuration, and larger specific surface area. It follows that Zr{sub 0.8}Sm{sub 0.2}O{sub 2??} nano-crystals are new visible-light-responsive photocatalysts which can be applied in dye wastewater treatment and environmental protection in the future.

  4. Fluorohydrogenate Cluster Ions in the Gas Phase: Electrospray Ionization Mass Spectrometry of the [1-Ethyl-3-methylimidazolium+][F(HF)2.3–] Ionic Liquid

    SciTech Connect (OSTI)

    Gary S. Groenewold; James E. Delmore; Michael T. Benson; Tetsuya Tsuda; Rika Hagiwara

    2013-12-01

    Electrospray ionization of the fluorohydrogenate ionic liquid [1-ethyl-3-methylimidazolium][F(HF)2.3] ionic liquid was conducted to understand the nature of the anionic species as they exist in the gas phase. Abundant fluorohydrogenate clusters were produced; however, the dominant anion in the clusters was [FHF-], and not the fluoride-bound HF dimers or trimers that are seen in solution. Density functional theory (DFT) calculations suggest that HF molecules are bound to the clusters by about 30 kcal/mol. The DFT-calculated structures of the [FHF-]-bearing clusters show that the favored interactions of the anions are with the methynic and acetylenic hydrogen atoms on the imidazolium cation, forming planar structures similar to those observed in the solid state. A second series of abundant negative ions was also formed that contained [SiF5-] together with the imidazolium cation and the fluorohydrogenate anions that originate from reaction of the spray solution with silicate surfaces.

  5. Demonstrating 1 nm-oxide-equivalent-thickness HfO{sub 2}/InSb structure with unpinning Fermi level and low gate leakage current density

    SciTech Connect (OSTI)

    Trinh, Hai-Dang [Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, Hsinchu, Taiwan (China) [Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, Hsinchu, Taiwan (China); Department of Physics, Hanoi National University of Education, 136 Xuan Thuy, Cau Giay, Hanoi (Viet Nam); Lin, Yueh-Chin; Nguyen, Hong-Quan; Luc, Quang-Ho [Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, Hsinchu, Taiwan (China)] [Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, Hsinchu, Taiwan (China); Nguyen, Minh-Thuy; Duong, Quoc-Van; Nguyen, Manh-Nghia [Department of Physics, Hanoi National University of Education, 136 Xuan Thuy, Cau Giay, Hanoi (Viet Nam)] [Department of Physics, Hanoi National University of Education, 136 Xuan Thuy, Cau Giay, Hanoi (Viet Nam); Wang, Shin-Yuan [Department of Electronic Engineering, National Chiao Tung University 1001, University Rd., Hsinchu 300, Taiwan (China)] [Department of Electronic Engineering, National Chiao Tung University 1001, University Rd., Hsinchu 300, Taiwan (China); Yi Chang, Edward [Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, Hsinchu, Taiwan (China) [Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, Hsinchu, Taiwan (China); Department of Electronic Engineering, National Chiao Tung University 1001, University Rd., Hsinchu 300, Taiwan (China)

    2013-09-30

    In this work, the band alignment, interface, and electrical characteristics of HfO{sub 2}/InSb metal-oxide-semiconductor structure have been investigated. By using x-ray photoelectron spectroscopy analysis, the conduction band offset of 1.78 ± 0.1 eV and valence band offset of 3.35 ± 0.1 eV have been extracted. The transmission electron microscopy analysis has shown that HfO{sub 2} layer would be a good diffusion barrier for InSb. As a result, 1 nm equivalent-oxide-thickness in the 4 nm HfO{sub 2}/InSb structure has been demonstrated with unpinning Fermi level and low leakage current of 10{sup ?4} A/cm{sup ?2}. The D{sub it} value of smaller than 10{sup 12} eV{sup ?1}cm{sup ?2} has been obtained using conduction method.

  6. Microstructure–property relationships in a high-strength 51Ni–29Ti–20Hf shape memory alloy

    SciTech Connect (OSTI)

    Coughlin, D. R.; Casalena, L.; Yang, F.; Noebe, R. D.; Mills, M. J.

    2015-09-18

    NiTiHf alloys exhibit remarkable shape memory and pseudoelastic properties that are of fundamental interest to a growing number of industries. In this study, differential scanning calorimetry and isothermal compression tests have revealed that the 51Ni–29Ti–20Hf alloy has useful shape memory properties that include a wide range of transformation temperatures as well as highly stable pseudoelastic behavior. These properties are governed by short-term aging conditions, which may be tailored to control transformation temperatures while giving rise to exceptionally high austenite yield strengths which aid transformation stability. The yield strength of the austenite phase can reach 2.1 GPa by aging for 3hrs at 500°C, while aging for 3hrs at 700°C produced an alloy with an austenite finish temperature (A f ) of 146°C. High-resolution scanning transmission electron microscopy has revealed a new precipitate phase, H-phase, under the homogenized and extruded condition and the aged 3 hrs at 500°C condition, but only the previously identified H-phase precipitate was observed after aging at temperatures of 600°C and 700°C for 3 hrs. Finally, dislocation analysis indicated that plastic deformation of the austenite phase occurred by <100> type slip, similar to that observed in binary NiTi.

  7. Microstructure–property relationships in a high-strength 51Ni–29Ti–20Hf shape memory alloy

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

    Coughlin, D. R.; Casalena, L.; Yang, F.; Noebe, R. D.; Mills, M. J.

    2015-09-18

    NiTiHf alloys exhibit remarkable shape memory and pseudoelastic properties that are of fundamental interest to a growing number of industries. In this study, differential scanning calorimetry and isothermal compression tests have revealed that the 51Ni–29Ti–20Hf alloy has useful shape memory properties that include a wide range of transformation temperatures as well as highly stable pseudoelastic behavior. These properties are governed by short-term aging conditions, which may be tailored to control transformation temperatures while giving rise to exceptionally high austenite yield strengths which aid transformation stability. The yield strength of the austenite phase can reach 2.1 GPa by aging for 3hrsmore »at 500°C, while aging for 3hrs at 700°C produced an alloy with an austenite finish temperature (A f ) of 146°C. High-resolution scanning transmission electron microscopy has revealed a new precipitate phase, H-phase, under the homogenized and extruded condition and the aged 3 hrs at 500°C condition, but only the previously identified H-phase precipitate was observed after aging at temperatures of 600°C and 700°C for 3 hrs. Finally, dislocation analysis indicated that plastic deformation of the austenite phase occurred by type slip, similar to that observed in binary NiTi.« less

  8. Synthesis of bulk FeHfBO soft magnetic materials and its loss characterization at megahertz frequency

    SciTech Connect (OSTI)

    Zhou Yang; Kou Xiaoming; Warsi Muhammad, Asif; Lin Shuo; Harris, Brendan S.; Parsons, Paul E.; Xiao, John Q. [Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716 (United States); Mu Mingkai; Lee, Fred C. [Center for Power Electronics System, Virginia Polytechnic and State University, Blacksburg, Virginia 24060 (United States); Zhu Hao [Spectrum Magnetics LLC, Wilmington, Delaware 19804 (United States)

    2013-05-07

    Magnetic core materials with low loss, high saturation magnetization, large permeability, and operating frequency above 1 MHz are in high demands for the next generation of miniaturized power electronics. Amorphous FeHfB ribbons with thickness around 20 {mu}m have been fabricated through melt-spinning. Different heat treatments were performed on the FeHfB ribbons, and the relations among heat treatments, microstructure, and magnetic properties have been explored. Properties such as coercivity (H{sub c}) of 2.0 Oe and saturation magnetic flux density (B{sub S}) of 1.2 T have been achieved in samples with exchange coupling. The losses can be minimized by balancing the hysteretic and eddy current losses and can be further reduced with additional magnetic field annealing. At 5 MHz with peak magnetic flux density of 20 mT, the materials show core losses comparable to the best ferrites, but with higher permeability value of about 200 and superior saturation induction of more than 1 T.

  9. Features of conduction mechanisms in n-HfNiSn semiconductor heavily doped with a Rh acceptor impurity

    SciTech Connect (OSTI)

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

    2013-09-15

    The crystal structure and electron-density distribution, as well as the energy, kinetic, and magnetic characteristics of n-HfNiSn intermetallic semiconductor heavily doped with a Rh acceptor impurity in the temperature range T = 80-400 K, in the acceptor-concentration range N{sub A}{sup Rh} Almost-Equal-To 9.5 Multiplication-Sign 10{sup 19}-1.9 Multiplication-Sign 10{sup 21} cm{sup -3} (x = 0.005-0.10), and in magnetic fields H {<=} 10 kG are investigated. It is established that doping is accompanied by a simultaneous decrease in concentration, the elimination of donor-type structural defects (to x Almost-Equal-To 0.02), and an increase in the concentration of acceptor-type structural defects (0 < x {<=} 0.10). The dependence of the degree of semiconductor compensation on temperature is revealed. A model of the spatial arrangement of atoms in HfNi{sub 1-x}Rh{sub x}Sn is proposed, and the results of calculating the electron structure based on this model agree with the results of investigations of the kinetic and magnetic characteristics of the semiconductor. The results are discussed within the context of the Shklovskii-Efros model for a heavily doped and compensated semiconductor.

  10. Ge MOS Characteristics with CVD HfO2 Gate Dielectrics and TaN Gate Electrode W. P. Bai*, N. Lu*, J. Liu*, A. Ramirez**, D. L. Kwong*, D. Wristers**, A. Ritenour#

    E-Print Network [OSTI]

    Ge MOS Characteristics with CVD HfO2 Gate Dielectrics and TaN Gate Electrode W. P. Bai*, N. Lu*, J, we report for the first time Ge MOS characteristics with ultra thin rapid thermal CVD HfO2 gate dielectrics and TaN gate electrode. Using the newly developed pre- gate cleaning and NH3-based Ge surface

  11. Generation of Realistic Amorphous Al2O3 And ZrO2 Samples By Hybrid Classical and First-Principle Molecular Dynamics Simulations

    E-Print Network [OSTI]

    Kummel, Andrew C.

    Generation of Realistic Amorphous Al2O3 And ZrO2 Samples By Hybrid Classical and First-ZrO2 were generated by a hybrid classical and density functional theory (DFT) "melt and quench" molecular dynamics approach. The generated samples demonstrated good correlation with reference experimental

  12. Synthesis and hydration behavior of calcium zirconium aluminate (Ca{sub 7}ZrAl{sub 6}O{sub 18}) cement

    SciTech Connect (OSTI)

    Kang, Eun-Hee [Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 151-744 (Korea, Republic of)] [Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 151-744 (Korea, Republic of); Yoo, Jun-Sang [Department of Oral and Maxillofacial Surgery, School of Dentistry, Seoul National University, Seoul 110-749 (Korea, Republic of)] [Department of Oral and Maxillofacial Surgery, School of Dentistry, Seoul National University, Seoul 110-749 (Korea, Republic of); Kim, Bo-Hye; Choi, Sung-Woo [Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 151-744 (Korea, Republic of)] [Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 151-744 (Korea, Republic of); Hong, Seong-Hyeon, E-mail: shhong@snu.ac.kr [Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 151-744 (Korea, Republic of)] [Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 151-744 (Korea, Republic of)

    2014-02-15

    Calcium zirconium aluminate (Ca{sub 7}ZrAl{sub 6}O{sub 18}) cements were prepared by solid state reaction and polymeric precursor methods, and their phase evolution, morphology, and hydration behavior were investigated. In polymeric precursor method, a nearly single phase Ca{sub 7}ZrAl{sub 6}O{sub 18} was obtained at relatively lower temperature (1200 °C) whereas in solid state reaction, a small amount of CaZrO{sub 3} coexisted with Ca{sub 7}ZrAl{sub 6}O{sub 18} even at higher temperature (1400 °C). Unexpectedly, Ca{sub 7}ZrAl{sub 6}O{sub 18} synthesized by polymeric precursor process was the large-sized and rough-shaped powder. The planetary ball milling was employed to control the particle size and shape. The hydration behavior of Ca{sub 7}ZrAl{sub 6}O{sub 18} was similar to that of Ca{sub 3}Al{sub 2}O{sub 6} (C3A), but the hydration products were Ca{sub 3}Al{sub 2}O{sub 6}·6H{sub 2}O (C3AH6) and several intermediate products. Thus, Zr (or ZrO{sub 2}) stabilized the intermediate hydration products of C3A.

  13. Structural Evolving Sequence and Porous Ba6Zr2Nb8O30 Ferroelectric Ceramics with Ultrahigh Breakdown Field and Zero Strain

    E-Print Network [OSTI]

    Cao, Wenwu

    Structural Evolving Sequence and Porous Ba6Zr2Nb8O30 Ferroelectric Ceramics with Ultrahigh of relaxor ferroelectric Ba6Zr2Nb8O30 (BZN) ceramics has been investigated and dis- cussed. Porous BZN, which refinements determine the atomic positions and confirm that the porous ceramics has tetragonal tungsten bronze

  14. A Novel Combustion Synthesis Preparation of CuO/ZnO/ZrO2/Pd for Oxidative Hydrogen Production from Methanol

    E-Print Network [OSTI]

    Mukasyan, Alexander

    , selectively forming hydrogen and carbon mon- oxide [5­8]. However, when palladium is prepared with ZnO or ZrO2A Novel Combustion Synthesis Preparation of CuO/ZnO/ZrO2/Pd for Oxidative Hydrogen Production from Abstract Complex catalysts containing combinations of copper, zinc, zirconium, and palladium oxides were

  15. SEM in situ MiniCantilever Beam Bending of U-10Mo/Zr/Al Fuel Elements

    SciTech Connect (OSTI)

    Mook, William; Baldwin, Jon K.; Martinez, Ricardo M.; Mara, Nathan A.

    2014-06-16

    In this work, the fracture behavior of Al/Zr and Zr/dU-10Mo interfaces was measured via the minicantilever bend technique. The energy dissipation rates were found to be approximately 3.7-5 mj/mm2 and 5.9 mj/mm2 for each interface, respectively. It was found that in order to test the Zr/U-10Mo interface, location of the hinge of the cantilever was a key parameter. While this test could be adapted to hot cell use through careful alignment fixturing and measurement of crack lengths with an optical microscope (as opposed to SEM, which was used here out of convenience), machining of the cantilevers via MiniMill in such a way as to locate the interfaces at the cantilever hinge, as well as proper placement of a femtosecond laser notch will continue to be key challenges in a hot cell environment.

  16. Modeling of constituent redistribution in U-Pu-Zr metallic fuel.

    SciTech Connect (OSTI)

    Kim, Y. S.; Hofman, G. L.; Hayes, S. L.; Yacout, A. M.; Nuclear Engineering Division; INL

    2006-12-01

    A computer model was developed to analyze constituent redistribution in U-Pu-Zr metallic nuclear fuels. Diffusion and thermochemical properties were parametrically determined to fit the postirradiation data from a fuel test performed in the Experimental Breeder Reactor II (EBR-II). The computer model was used to estimate redistribution profiles of fuels proposed for the conceptual designs of small modular fast reactors. The model results showed that the level of redistribution of the fuel constituents of the designs was similar to the measured data from EBR-II.

  17. Projected shell model study of neutron-rich deformed isotopes of Sr and Zr

    SciTech Connect (OSTI)

    Verma, Sonia; Dar, Parvaiz Ahmad; Devi, Rani [Department of Physics and Electronics, University of Jammu, Jammu-180006 (India)

    2008-02-15

    The projected shell model (PSM) study of {sup 98-102}Sr and {sup 100-104}Zr nuclei is carried out. The reliability of the ground-state wave function is checked by reproducing yrast spectra and electromagnetic properties. The mechanism for the onset of sudden and large deformation at N=60 is worked out. The present piece of research work has unified the two different, or conflicting, early explanations for the onset of deformation at N=60 by the spherical shell model and mean-field theory.

  18. Fundamental science investigations to develop a 6-MV laser triggered gas switch for ZR: first annual report.

    SciTech Connect (OSTI)

    Warne, Larry Kevin; Van Den Avyle, James A.; Lehr, Jane Marie; Rose, David; Krompholz, Hermann G.; Vela, Russell; Jorgenson, Roy Eberhardt; Timoshkin, Igor (University of Strathclyde, Glasgow, Scotland); Woodworth, Joseph Ray; Prestwich, Kenneth Randel (Voss Scientific, Albuquerque, NM); Krile, John; Given, Martin (University of Strathclyde, Glasgow, Scotland); McKee, G. Randall; Rosenthal, Stephen Edgar; Struve, Kenneth William; Welch, Dale Robert (Voss Scientific, Albuquerque, NM); Benwell, Andrew L. (University of Missouri-Columbia, Columbia, Missouri); Kovaleski, Scott; LeChien, Keith, R.; Johnson, David (Titan Pulse Sciences Division); Fouracre, R.A. (University of Strathclyde, Glasgow, Scotland); Yeckel, Chris (University of Missouri-Columbia, Columbia, Missouri); Wakeland, Peter Eric; Miller, A. R. (Titan Pulse Sciences Division); Hodge, Keith Conquest (Ktech Corporation, Albuquerque, NM); Pasik, Michael Francis; Savage, Mark Edward; Maenchen, John Eric; Curry, Randy D.; Feltz, Greg; Bliss, David Emery; MacGregor, Scott (University of Strathclyde, Glasgow, Scotland); Corley, J. P. (Ktech Corporation, Albuquerque, NM); Anaya, Victor (Ktech Corporation, Albuquerque, NM); Wallace, Zachariah (Ktech Corporation, Albuquerque, NM); Thoma, Carsten (Voss Scientific, Albuquerque, NM); Neuber, Andreas. (Texas Tech University, Lubbock, TX)

    2007-03-01

    In October 2005, an intensive three-year Laser Triggered Gas Switch (LTGS) development program was initiated to investigate and solve observed performance and reliability issues with the LTGS for ZR. The approach taken has been one of mission-focused research: to revisit and reassess the design, to establish a fundamental understanding of LTGS operation and failure modes, and to test evolving operational hypotheses. This effort is aimed toward deploying an initial switch for ZR in 2007, on supporting rolling upgrades to ZR as the technology can be developed, and to prepare with scientific understanding for the even higher voltage switches anticipated needed for future high-yield accelerators. The ZR LTGS was identified as a potential area of concern quite early, but since initial assessments performed on a simplified Switch Test Bed (STB) at 5 MV showed 300-shot lifetimes on multiple switch builds, this component was judged acceptable. When the Z{sub 20} engineering module was brought online in October 2003 frequent flashovers of the plastic switch envelope were observed at the increased stresses required to compensate for the programmatically increased ZR load inductance. As of October 2006, there have been 1423 Z{sub 20} shots assessing a variety of LTGS designs. Numerous incremental and fundamental switch design modifications have been investigated. As we continue to investigate the LTGS, the basic science of plastic surface tracking, laser triggering, cascade breakdown, and optics degradation remain high-priority mission-focused research topics. Significant progress has been made and, while the switch does not yet achieve design requirements, we are on the path to develop successively better switches for rolling upgrade improvements to ZR. This report summarizes the work performed in FY 2006 by the large team. A high-level summary is followed by detailed individual topical reports.

  19. In situ observation of defect annihilation in Kr ion-irradiated bulk Fe/amorphous-Fe 2 Zr nanocomposite alloy

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

    Yu, K. Y.; Fan, Z.; Chen, Y.; Song, M.; Liu, Y.; Wang, H.; Kirk, M. A.; Li, M.; Zhang, X.

    2014-08-26

    Enhanced irradiation tolerance in crystalline multilayers has received significant attention lately. However, little is known on the irradiation response of crystal/amorphous nanolayers. We report on in situ Kr ion irradiation studies of a bulk Fe96Zr4 nanocomposite alloy. Irradiation resulted in amorphization of Fe2Zr and formed crystal/amorphous nanolayers. ?-Fe layers exhibited drastically lower defect density and size than those in large ?-Fe grains. In situ video revealed that mobile dislocation loops in ?-Fe layers were confined by the crystal/amorphous interfaces and kept migrating to annihilate other defects. This study provides new insights on the design of irradiation-tolerant crystal/amorphous nanocomposites.

  20. Improved high temperature refractory. [MgCr/sub 2/O/sub 4/ composite with ZrO/sub 2/

    DOE Patents [OSTI]

    Singh, J.P.; James, J.; Picciolo, J.J.

    1985-12-10

    A high chromia refractory composite has been developed with improved thermal shock resistance and containing about 5 to 30 wt % of unstabilized ZrO/sub 2/ having a temperature-dependent phase change resulting in large expansion mismatch between the ZrO/sub 2/ and the chromia matrix which causes microcracks to form during cooling in the high chromia matrix. The particle size preferably is primarily between about 0.6 to 5 microns and particularly below about 3 microns with an average size in the order of 1.2 to 1.8 microns.

  1. Diffusional Interaction between U-10 wt.% Zr and Fe at 903K, 923K and 953K (630°C, 650°C, and 680°C)

    SciTech Connect (OSTI)

    Park, K Y.; Huang, K.; Paz y Puente, A.; Lee, H. S.; Sencer, B. H.; Kennedy, J. R.

    2014-04-15

    U-Zr metallic fuels cladded in Fe-alloys are being considered for application in an advanced Sodium-Cooled Fast Reactor (SFR) that can recycle the U-Zr fuels and minimize the long-lived actinide waste. To understand the complex fuel-cladding chemical interaction between the U-Zr metallic fuel with Fe-alloys, a systematic multicomponent diffusion study was carried out using solid-to-solid diffusion couples. The U-10 wt.% Zr vs. pure Fe diffusion couples were assembled and annealed at temperatures, 903, 923 and 953K for 96 hours. Development of microstructure, phase constituents, and compositions developed during the thermal anneals were examined by scanning electron microscopy, transmission electron microscopy and X-ray energy dispersive spectroscopy. Complex microstructure consisting of several layers that include phases such as U6Fe, UFe2, ZrFe2, ?-U, ?-U, Zr-precipitates, ?, ? and ? were observed. Multi-phase layers were grouped based on phase constituents and microstructure, and the layer thicknesses were measured to calculate the growth constant and activation energy. The local average compositions through the interaction layer were systematically determined, and employed to construct semi-quantitative diffusion paths on isothermal U-Zr-Fe ternary phase diagrams at respective temperatures. The diffusion paths were examined to qualitatively estimate the diffusional behavior of individual components and their interactions. Furthermore, selected area diffraction analyses were carried out to determine, for the first time, the exact crystal structure and composition of ?, ? and ?-phases. The ?, ? and ?-phases were identified as Pnma(62) Fe(Zr,U), I4/mcm(140) Fe(Zr,U)2, and I4/mcm(140) U3(Zr,Fe), respectively.

  2. Voltammetry and Impedance Studies of Ta in Aqueous HF Sanjeev Sapra, Hongqi Li, Zuocheng Wang, and Ian Ivar Suni*,z

    E-Print Network [OSTI]

    Suni, Ian Ivar

    , and Ian Ivar Suni*,z a Department of Chemical Engineering, Center for Advanced Materials Processing hydrogen evolution current and the much lower charge-transfer resistance for the high-frequency impedance both Ti/TiN7-9 and Ta/TaN10-17 diffusion barriers. Fluoroborate solutions, in which HF can form

  3. Structural and electronic properties of cubic HfO2 surfaces G.H. Chen, Z.F. Hou, X.G. Gong *

    E-Print Network [OSTI]

    Gong, Xingao

    Structural and electronic properties of cubic HfO2 surfaces G.H. Chen, Z.F. Hou, X.G. Gong@fudan.edu.cn (X.G. Gong). www.elsevier.com/locate/commatsci Available online at www

  4. Field emission from single-crystalline HfC nanowires Jinshi Yuan, Han Zhang, Jie Tang, Norio Shinya, Kiyomi Nakajima et al.

    E-Print Network [OSTI]

    Qin, Lu-Chang

    based on nickel inverse opal slabs J. Appl. Phys. 111, 07A948 (2012) Interfacial stabilization molecules and ion bombardment.4 Single-crystalline nanowires as well as carbon nanotubes possess a unique nanotubes in our previous work.5­12 Therefore, an HfC nanowire emitter can poten- tially provide a more

  5. Coupled LuHf and SmNd geochronology constrains prograde and exhumation histories of high-and ultrahigh-pressure

    E-Print Network [OSTI]

    Hacker, Bradley R.

    Coupled Lu­Hf and Sm­Nd geochronology constrains prograde and exhumation histories of high; Geochronology; Norway 1. Introduction The Western Gneiss Region (WGR) of Norway exposes high-pressure (HP and the mantle, and generation of continental crust. Despite abundant structural, geochronologic and pressure

  6. In-Line-Test of Variability and Bit-Error-Rate of HfOx-Based Resistive Memory

    E-Print Network [OSTI]

    Ji, B L; Ye, Q; Gausepohl, S; Deora, S; Veksler, D; Vivekanand, S; Chong, H; Stamper, H; Burroughs, T; Johnson, C; Smalley, M; Bennett, S; Kaushik, V; Piccirillo, J; Rodgers, M; Passaro, M; Liehr, M

    2015-01-01

    Spatial and temporal variability of HfOx-based resistive random access memory (RRAM) are investigated for manufacturing and product designs. Manufacturing variability is characterized at different levels including lots, wafers, and chips. Bit-error-rate (BER) is proposed as a holistic parameter for the write cycle resistance statistics. Using the electrical in-line-test cycle data, a method is developed to derive BERs as functions of the design margin, to provide guidance for technology evaluation and product design. The proposed BER calculation can also be used in the off-line bench test and build-in-self-test (BIST) for adaptive error correction and for the other types of random access memories.

  7. Electron band theory predictions and the construction of phase diagrams. [HfPt; TaIr; WOs

    SciTech Connect (OSTI)

    Watson, R.E.; Bennett, L.H.; Davenport, J.W.; Weinert, M.

    1985-01-01

    The a priori theory of metals is yielding energy results which are relevant to the construction of phase diagrams - to the solution phases as well as to line compounds. There is a wide range in the rigor of the calculations currently being done and this is discussed. Calculations for the structural stabilities (fcc vs bcc vs hcp) of the elemental metals, quantities which are employed in the constructs of the terminal phases, are reviewed and shown to be inconsistent with the values currently employed in such constructs (also see Miodownik elsewhere in this volume). Finally, as an example, the calculated heats of formation are compared with experiment for PtHf, IrTa and OsW, three compounds with the same electron to atom ratio but different bonding properties.

  8. In situ study of HfO{sub 2} atomic layer deposition on InP(100)

    SciTech Connect (OSTI)

    Dong, H.; Brennan, B.; Kim, J.; Hinkle, C. L.; Wallace, R. M. [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080 (United States)] [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080 (United States); Zhernokletov, D. [Department of Physics, University of Texas at Dallas, Richardson, Texas 75080 (United States)] [Department of Physics, University of Texas at Dallas, Richardson, Texas 75080 (United States)

    2013-04-29

    The interfacial chemistry of the native oxide and chemically treated InP samples during atomic layer deposition (ALD) HfO{sub 2} growth at 250 Degree-Sign C has been studied by in situ X-ray photoelectron spectroscopy. The In-oxide concentration is seen to gradually decrease on the native oxide and acid etched samples. No significant changes of the P-oxide concentrations are detected, while the P-oxides chemical states are seen to change gradually during the initial cycles of ALD on the native oxide and the chemically treated samples. (NH{sub 4}){sub 2}S treatment strongly decreases In-oxide and P-oxide concentrations prior to ALD and maintains low concentrations during the ALD process.

  9. On stability of self-sustained volume discharge in working mixtures of non-chain electrochemical HF laser

    SciTech Connect (OSTI)

    Belevtsev, A A; Kazantsev, S Yu; Konov, I G; Lebedev, A A; Podlesnykh, S V; Firsov, K N

    2011-08-31

    Burning voltage of a self-sustained volume discharge (SSVD) is studied as a function of the specific energy deposition in SF{sub 5} with C{sub 2}-H{sub 6} and H{sub 2} mixtures, which are working media of a non-chain electrochemical HF laser. It is established that the voltage rises linearly with increasing the specific energy deposition, the relative voltage rise in the SF{sub 6}-C{sub 2}H{sub 6} mixtures being noticeably higher than in pure SF{sub 6} and SF{sub 6}-H{sub 2} mixtures. An assumption is suggested and substantiated on determining the role of molecule dissociation by the electron impact leading to the observed voltage rise. From experimental data we have found approximate energy expenditures of producing dissociation fragments including atomic fluorine in a discharge in pure SF{sub 6}: E-tilde {sub d}(F)= 5{+-}1 eV. The values of E{sub d} well agree with literature data obtained by other experimental methods. A conclusion is drawn that the dissociation process is the main mechanism limiting the current density, which implies SSVD realisation without preliminary gas ionisation in working mixtures of a non-chain HF laser and determines a higher stability of the volume discharge in mixtures of SF{sub 6} with hydrocarbons (deuterocarbons) as compared to mixtures with hydrogen (deuterium). A method is suggested and substantiated for numerical estimation of the limitation effect of the current density and its influence on the SSVD stability. (control of radiation parameters)

  10. Electronic and mechanical properties of Zr{sub 2}TiAl: A first principles study

    SciTech Connect (OSTI)

    Reddy, P. V. Sreenivasa, E-mail: kanchana@iith.ac.in; Kanchana, V., E-mail: kanchana@iith.ac.in [Department of Physics, Indian Institute of Technology Hyderabad, Ordnance Factory Estate, Yeddumailaram-502205, Andhra Pradesh (India)

    2014-04-24

    First principles study of electronic and mechanical properties of ternary phase Zr{sub 2}TiAl intermetallic compound has been carried out by using full potential linear augmented plane wave (FP-LAPW) method. Our calculated lattice parameter is in good agreement with the experiment. We find the magnetic phase of the compound to be stable with a magnetic moment of 1.95 ?{sub B}. The major contribution to the total magnetic moment arises mainly from the Ti atom with the local magnetic moment of 1.22 ?{sub B}. From the density of states plots we find the Ti-d and Zr-d to dominate at the Fermi level (E{sub F}) with enhanced crystal field splitting and exchange splitting found in Ti. The mechanical stability of the compound is confirmed from the calculated elastic constants, and we find the compound to be ductile in nature from the calculated Pugh’s ratio and Cauchy’s pressure.

  11. Magnetic Force Microscopy Study of Zr2Co11 -Based Nanocrystalline Materials: Effect of Mo Addition

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

    Yue, Lanping; Jin, Yunlong; Zhang, Wenyong; Sellmyer, David J.

    2015-01-01

    The addition of Molybdenum was used to modify the nanostructure and enhance coercivity of rare-earth-free Zr2Co11-based nanocrystalline permanent magnets. The effect of Mo addition on magnetic domain structures of melt spun nanocrystalline Zr16Co84-xMox(x=0, 0.5, 1, 1.5, and 2.0) ribbons has been investigated. It was found that magnetic properties and local domain structures are strongly influenced by Mo doping. The coercivity of the samples increases with the increase in Mo content (x?1.5). The maximum energy product(BH)maxincreases with increasingxfrom 0.5?MGOe forx=0to a maximum value of 4.2?MGOe forx=1.5. The smallest domain size with a relativelymore »short magnetic correlation length of 128?nm and largest root-mean-square phase shift?rmsvalue of 0.66° are observed for thex=1.5. The optimal Mo addition promotes magnetic domain structure refinement and thus leads to a significant increase in coercivity and energy product in this sample.« less

  12. ZrN coatings deposited by high power impulse magnetron sputtering and cathodic arc techniques

    SciTech Connect (OSTI)

    Purandare, Yashodhan Ehiasarian, Arutiun; Hovsepian, Papken; Santana, Antonio

    2014-05-15

    Zirconium nitride (ZrN) coatings were deposited on 1??m finish high speed steel and 316L stainless steel test coupons. Cathodic Arc (CA) and High Power Impulse Magnetron Sputtering (HIPIMS) + Unbalanced Magnetron Sputtering (UBM) techniques were utilized to deposit coatings. CA plasmas are known to be rich in metal and gas ions of the depositing species as well as macroparticles (droplets) emitted from the arc sports. Combining HIPIMS technique with UBM in the same deposition process facilitated increased ion bombardment on the depositing species during coating growth maintaining high deposition rate. Prior to coating deposition, substrates were pretreated with Zr{sup +} rich plasma, for both arc deposited and HIPIMS deposited coatings, which led to a very high scratch adhesion value (L{sub C2}) of 100 N. Characterization results revealed the overall thickness of the coatings in the range of 2.5??m with hardness in the range of 30–40?GPa depending on the deposition technique. Cross-sectional transmission electron microscopy and tribological experiments such as dry sliding wear tests and corrosion studies have been utilized to study the effects of ion bombardment on the structure and properties of these coatings. In all the cases, HIPIMS assisted UBM deposited coating fared equal or better than the arc deposited coatings, the reasons being discussed in this paper. Thus H+U coatings provide a good alternative to arc deposited where smooth, dense coatings are required and macrodroplets cannot be tolerated.

  13. Precipitation in a Cu–Cr–Zr–Mg alloy during aging

    SciTech Connect (OSTI)

    Cheng, J.Y. Shen, B.; Yu, F.X.

    2013-07-15

    The precipitation processes in a Cu-0.69Cr-0.10Zr-0.02Mg alloy aged at 450 °C and 550 °C have been investigated by transmission electron microscopy and high resolution transmission electron microscopy. The precipitation sequence in this alloy aged at 450 °C is: supersaturated solid solution ? Guinier–Preston zone (fcc Cr-rich phase) ? ordered fcc Cr-rich phase ? ordered bcc Cr-rich phase. The precipitation sequence in this alloy aged at 550 °C is: supersaturated solid solution ? ordered fcc Cr-rich phase ? ordered bcc Cr-rich phase. In the evolution of decomposition, the orientation relationship between the precipitates and the Cu matrix changes from cube-on-cube to Nishiyama–Wassermann orientation. The ordering of Cr-rich precipitates facilitates the formation of the bcc precipitates and promotes the development of Nishiyama–Wassermann orientation. - Highlights: • Two different precipitation sequences in the Cu–Cr–Zr–Mg alloy are proposed. • The changes in orientation relationship of the precipitates are presented. • The roles of ordering and coherent interface of the precipitates are discussed.

  14. Synthesis and characterization of rare earth doped ZrO{sub 2} nanophosphors

    SciTech Connect (OSTI)

    Agrawal, Sadhana E-mail: jsvikasdubey@gmail.com; Dubey, Vikas E-mail: jsvikasdubey@gmail.com

    2014-10-24

    In this paper, we reports synthesis, characterization and thermoluminescence (TL) glow curves of europium and dysprosium activated zirconium dioxide (ZrO{sub 2}: Eu{sup 3+}, Dy{sup 3+}) phosphor with variable concentration of europium and fixed concentration of dysprosium. The sample was prepared by the Solid state method; thereafter, the TL glow curves were recorded for different concentration of europium with 20 min UV exposure at a heating rate of 6.7°C/s. The trapping parameters for synthesized phosphors of ZrO{sub 2}: Eu{sup 3+}, Dy{sup 3+} have been calculated by using a peak shape method. The sample was characterized for structural analysis by XRD (X-ray diffraction) and morphological analysis by FEGSEM (field emission gun scanning electron microscope) and FTIR (Fourier transform infrared spectroscopy). The effect of variable europium concentration and fixed dysprosium concentration on TL studies were interpreted and the formation of trap depth and reproducibility of prepared phosphor were analyzed by TL glow curves. The peak temperature on TL less than 200°C shows the formation of deep trapping in prepared sample. The high temperature peak shows the less fading and more stability in prepared sample.

  15. New Insights into Reaction Mechanisms of Ethanol Steam Reforming on Co-ZrO2

    SciTech Connect (OSTI)

    Sun, Junming; Karim, Ayman M.; Mei, Donghai; Engelhard, Mark H.; Bao, Xinhe; Wang, Yong

    2015-01-01

    The reaction pathway of ethanol steam reforming on Co-ZrO2 has been identified and the active sites associated with each step are proposed. Ethanol is converted to acetaldehyde and then to acetone, followed by acetone steam reforming. More than 90% carbon was found to follow this reaction pathway. N2-Sorption, X-ray Diffraction (XRD), Temperature Programmed Reduction (TPR), in situ X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscopy, as well as theoretical Density Functional Theory (DFT) calculations have been employed to identify the structure and functionality of the catalysts, which was further used to correlate their performance in ESR. It was found that metallic cobalt is mainly responsible for the acetone steam reforming reactions; while, CoO and basic sites on the support play a key role in converting ethanol to acetone via dehydrogenation and condensation/ketonization reaction pathways. The current work provides fundamental understanding of the ethanol steam reforming reaction mechanisms on Co-ZrO2 catalysts and sheds light on the rational design of selective and durable ethanol steam reforming catalysts.

  16. Phase-field modeling of the beta to omega phase transformation in Zr–Nb alloys

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

    Yeddu, Hemantha Kumar; Lookman, Turab

    2015-05-01

    A three-dimensional elastoplastic phase-field model is developed, using the Finite Element Method (FEM), for modeling the athermal beta to omega phase transformation in Zr–Nb alloys by including plastic deformation and strain hardening of the material. The microstructure evolution during athermal transformation as well as under different stress states, e.g. uni-axial tensile and compressive, bi-axial tensile and compressive, shear and tri-axial loadings, is studied. The effects of plasticity, stress states and the stress loading direction on the microstructure evolution as well as on the mechanical properties are studied. The input data corresponding to a Zr – 8 at.% Nb alloy aremore »acquired from experimental studies as well as by using the CALPHAD method. Our simulations show that the four different omega variants grow as ellipsoidal shaped particles. Our results show that due to stress relaxation, the athermal phase transformation occurs slightly more readily in the presence of plasticity compared to that in its absence. The evolution of omega phase is different under different stress states, which leads to the differences in the mechanical properties of the material. The variant selection mechanism, i.e. formation of different variants under different stress loading directions, is also nicely captured by our model.« less

  17. Determination of the displacement energy of O, Si and Zr under electron beam irradiation

    SciTech Connect (OSTI)

    Edmondson, Philip D; Weber, William J; Namavar, Fereydoon; Zhang, Yanwen

    2012-01-01

    The response of nanocrystalline, stabilizer-free cubic zirconia thin films on a Si substrate to electron beam irradiation with energies of 4, 110 and 200 keV and fluences up to {approx}1.5 x 10{sup 22} e m{sup -2} has been studied to determine the displacement energies. The 110 and 200 keV irradiations were performed in situ using a transmission electron microscope; the 4 keV irradiations were performed ex situ using an electron gun. In all three irradiations, no structural modification of the zirconia was observed, despite the high fluxes and fluences. However the Si substrate on which the zirconia film was deposited was amorphized under the 200 keV electron irradiation. Examination of the electron-solid interactions reveals that the kinetic energy transfer from the 200 keV electrons to the silicon lattice is sufficient to cause atomic displacements, resulting in amorphization. The kinetic energy transfer from the 200 keV electrons to the oxygen sub-lattice of the zirconia may be sufficient to induce defect production, however, no evidence of defect production was observed. The displacement cross-section value of Zr was found to be {approx}400 times greater than that of O indicating that the O atoms are effectively screened from the electrons by the Zr atoms, and, therefore, the displacement of O is inefficient.

  18. Determination of the Displacement Energies of O, Si and Zr Under Electron Beam Irradiation

    SciTech Connect (OSTI)

    Edmondson, P. D.; Weber, William J.; Namavar, Fereydoon; Zhang, Yanwen

    2012-03-01

    The response of nanocrystalline, stabilizer-free cubic zirconia thin films on a Si substrate to electron beam irradiation with energies of 4, 110 and 200 keV and fluences up to ~1.5 x 10²²e m² has been studied to determine the displacement energies. The 110 and 200 keV irradiations were performed in situ using a transmission electron microscope; the 4 keV irradiations were performed ex situ using an electron gun. In all three irradiations, no structural modification of the zirconia was observed, despite the high fluxes and fluences. However the Si substrate on which the zirconia film was deposited was amorphized under the 200 keV electron irradiation. Examination of the electron–solid interactions reveals that the kinetic energy transfer from the 200 keV electrons to the silicon lattice is sufficient to cause atomic displacements, resulting in amorphization. The kinetic energy transfer from the 200 keV electrons to the oxygen sub-lattice of the zirconia may be sufficient to induce defect production, however, no evidence of defect production was observed. The displacement cross-section value of Zr was found to be ~400 times greater than that of O indicating that the O atoms are effectively screened from the electrons by the Zr atoms, and, therefore, the displacement of O is inefficient.

  19. Synthesis of ZrO{sub 2} nanoparticles by hydrothermal treatment

    SciTech Connect (OSTI)

    Machmudah, Siti Widiyastuti, W. Prastuti, Okky Putri Nurtono, Tantular Winardi, Sugeng; Wahyudiono,; Kanda, Hideki; Goto, Motonobu

    2014-02-24

    Zirconium oxide (zirconia, ZrO{sub 2}) is the most common material used for electrolyte of solid oxide fuel cells (SOFCs). Zirconia has attracted attention for applications in optical coatings, buffer layers for growing superconductors, thermal-shield, corrosion resistant coatings, ionic conductors, and oxygen sensors, and for potential applications including transparent optical devices and electrochemical capacitor electrodes, fuel cells, catalysts, and advanced ceramics. In this work, zirconia particles were synthesized from ZrCl{sub 4} precursor with hydrothermal treatment in a batch reactor. Hydrothermal treatment may allow obtaining nanoparticles and sintered materials with controlled chemical and structural characteristics. Hydrothermal treatment was carried out at temperatures of 150 – 200°C with precursor concentration of 0.1 – 0.5 M. Zirconia particles obtained from this treatment were analyzed by using SEM, PSD and XRD to characterize the morphology, particle size distribution, and crystallinity, respectively. Based on the analysis, the size of zirconia particles were around 200 nm and it became smaller with decreasing precursor concentration. The increasing temperature caused the particles formed having uniform size. Zirconia particles formed by hydrothermal treatment were monoclinic, tetragonal and cubic crystal.

  20. Ordered omega derivatives in (Zr{sub 3}Al)-Nb alloys

    SciTech Connect (OSTI)

    Tewari, R.; Dey, G.K.; Mukhopadhyay, P.; Banerjee, S.; Bendersky, L.A.

    1998-12-31

    Various kinds of phase transformation, viz., spinodal decomposition, omega transformation, precipitation reactions and martensitic transformation can be induced in ternary (Zr{sub 3}Al)-Nb alloys in conditions far removed from equilibrium. Transformation sequences in alloys containing 3% niobium are described and rationalized in terms of some basic tendencies such as phase separation and chemical ordering in the {beta} (bcc) phase and displacive omega and {beta} to {alpha} (hcp) transformations. Microstructures of rapidly solidified alloy showed a distribution of cuboidal (D8{sub 8} phase) particles in the {beta} matrix. The periodic arrangement of these particles along the <100>{sub {beta}} directions was indicative of a spinodal transformation which preceded their formation. The {beta} {r_arrow} D8{sub 8} transformation could be accomplished by the superimposition of three processes, namely, chemical ordering, lattice collapse akin to {omega} transformation and vacancy ordering. During isothermal aging the D8{sub 8} phase transformed into the B8{sub 2} phase. The observed lattice correspondence and transformation morphology suggested that the D8{sub 8} to B8{sub 2} structural change involved the replacement of structural vacancies in the former by zirconium atoms without any reconstitution of the lattice. The evolution of the equilibrium Zr{sub 3}Al (L1{sub 2} structure) phase during prolonged aging were also studied.

  1. RAPIDLY MOVING DIVERTOR PLATES IN A TOKAMAK S.J. Zweben, R.A. Ellis, P. Titus, A. Xing, H. Zhang

    E-Print Network [OSTI]

    Princeton Plasma Physics Laboratory

    RAPIDLY MOVING DIVERTOR PLATES IN A TOKAMAK S.J. Zweben, R.A. Ellis, P. Titus, A. Xing, H. Zhang to replace conventional actively cooled tokamak divertor plates with a set of rapidly moving, passively inertia for ~10-30 sec, and would then be removed from the vessel for processing. When outside the tokamak

  2. 1. Use the Export function to download data from the RA forms in the RAE 2008 database into files. The Export function supports the following formats

    E-Print Network [OSTI]

    Abrahams, I. David

    1. Use the Export function to download data from the RA forms in the RAE 2008 database into files. The Export function supports the following formats: a. RAE 2008 XML file b. Microsoft Excel c. Microsoft. You can export data from several forms at a time into one file for each of the types a to c

  3. Comment on `Update of 40K and 226Ra and 232Th series $\\gamma$-to-dose conversion factors for soil'

    E-Print Network [OSTI]

    Malins, Alex; Saito, Kimiaki

    2015-01-01

    A letter to the editor of the Journal of Environmental Radioactivity on the article: E. Gasser, A. Nachab, A. Nourreddine, Ch. Roy, and A. Sellam, `Update of 40K and 226Ra and 232Th series $\\gamma$-to-dose conversion factors for soil', J. Environ. Radioactiv. 138, 68-71 (2014), DOI: 10.1016/j.jenvrad.2014.08.002.

  4. Heating Greenhouses1 D.E. Buffington, R.A. Bucklin, R.W. Henley and D.B. McConnell2

    E-Print Network [OSTI]

    Hill, Jeffrey E.

    AE11 Heating Greenhouses1 D.E. Buffington, R.A. Bucklin, R.W. Henley and D.B. McConnell2 1 T. Place , Dean A greenhouse has one purpose: to provide and maintain the environment or maintain desirable temperature and other environmental conditions in a greenhouse during those periods when

  5. arXiv:0810.4656v3[math.RA]11Nov2008 THE YONEDA ALGEBRA OF A K2 ALGEBRA NEED NOT

    E-Print Network [OSTI]

    Shelton, Brad

    arXiv:0810.4656v3[math.RA]11Nov2008 THE YONEDA ALGEBRA OF A K2 ALGEBRA NEED NOT BE ANOTHER K2 ALGEBRA Thomas Cassidy, Christopher Phan and Brad Shelton Department of Mathematics Bucknell University-1222 Abstract. The Yoneda algebra of a Koszul algebra or a D-Koszul al- gebra is Koszul. K2 algebras

  6. PRECIPITATION The images above use daily precipitation statistics fromNWS COOP, CoCoRaHS, and CoAgMet

    E-Print Network [OSTI]

    Collett Jr., Jeffrey L.

    PRECIPITATION The images above use daily precipitation statistics fromNWS COOP, CoCoRaHS, and CoAgMet stations. Fromtop to bottom, and left to right: most recent 7-days of accumulated precipitation in inches; current month-to-date accumulated precipitation in inches; last month's precipitation as a percent

  7. Fuel element design for the enhanced destruction of plutonium in a nuclear reactor

    DOE Patents [OSTI]

    Crawford, Douglas C. (Idaho Falls, ID); Porter, Douglas L. (Idaho Falls, ID); Hayes, Steven L. (Idaho Falls, ID); Hill, Robert N. (Bolingbrook, IL)

    1999-01-01

    A uranium-free fuel for a fast nuclear reactor comprising an alloy of Pu, Zr and Hf, wherein Hf is present in an amount less than about 10% by weight of the alloy. The fuel may be in the form of a Pu alloy surrounded by a Zr--Hf alloy or an alloy of Pu--Zr--Hf or a combination of both.

  8. Fuel element design for the enhanced destruction of plutonium in a nuclear reactor

    DOE Patents [OSTI]

    Crawford, D.C.; Porter, D.L.; Hayes, S.L.; Hill, R.N.

    1999-03-23

    A uranium-free fuel for a fast nuclear reactor comprising an alloy of Pu, Zr and Hf, wherein Hf is present in an amount less than about 10% by weight of the alloy. The fuel may be in the form of a Pu alloy surrounded by a Zr--Hf alloy or an alloy of Pu--Zr--Hf or a combination of both. 7 figs.

  9. Spin Glasses and Frustration Cynthia Olson, Chairman Transverse spin freezing in a-FexZr100x

    E-Print Network [OSTI]

    Ryan, Dominic

    Spin Glasses and Frustration Cynthia Olson, Chairman Transverse spin freezing in a-FexZr100x signatures of transverse spin freezing provides a clear confirmation of predictions from numerical models with random isotropic spin freezing and neither net magnetization nor long range order. At lower levels

  10. Stress-Induced Phase Transition in Pb(Zr1/2Ti1/2)O3

    E-Print Network [OSTI]

    Rappe, Andrew M.

    with available experimental data. Because many modern piezoelectric device applications involve longitudinal local density functional theory, the structural phase stability of the piezoelectric material Pb(Zr1/2Ti1/2)O3 (PZT) under finite applied uniaxial stress. Previous theoretical analyses of piezoelectric

  11. Broad Temperature Pinning Study of 15 mol.% Zr-Added (Gd, Y)-Ba-Cu-O MOCVD Coated Conductors

    SciTech Connect (OSTI)

    Xu, AX; Khatri, N; Liu, YH; Majkic, G; Galstyan, E; Selvamanickam, V; Chen, YM; Lei, CH; Abraimov, D; Hu, XB; Jaroszynski, J; Larbalestier, D

    2015-06-01

    BaZrO3 (BZO) nanocolumns have long been shown to be very effective for raising the pinning force F-p of REBa2Cu3Ox (REBCO, where RE = rare earth) films at high temperatures and recently at low temperatures too. We have successfully incorporated a high density of BZO nanorods into metal organic chemical vapor deposited (MOCVD) REBCO coated conductors via Zr addition. We found that, compared to the 7.5% Zr-added coated conductor, dense BZO nanorod arrays in the 15% Zr-added conductor are effective over the whole temperature range from 77 K down to 4.2 K. We attribute the substantially enhanced J(c) at 30 K to the weak uncorrelated pinning as well as the strong correlated pinning. Meanwhile, by tripling the REBCO layer thickness to similar to 2.8 mu m, the engineering critical current density J(e) at 30 K exceeds J(e) of optimized Nb-Ti wires at 4.2 K.

  12. SnO2 atomic layer deposition on ZrO2 and Al nanoparticles: Pathway to enhanced thermite materials

    E-Print Network [OSTI]

    George, Steven M.

    SnO2 atomic layer deposition on ZrO2 and Al nanoparticles: Pathway to enhanced thermite materials J of Colorado, Boulder, CO 80309-0414, United States Available online 1 June 2005 Abstract Thermite mixtures with traditional thermite mixtures. One technique to create thermite mixtures with improved contact is to deposit

  13. Effect of La2Zr2O7 on Interfacial Resistance in Solid Oxide J. R. Smith,a

    E-Print Network [OSTI]

    Florida, University of

    Effect of La2Zr2O7 on Interfacial Resistance in Solid Oxide Fuel Cells A. Chen,a J. R. Smith,a K. L manuscript received August 9, 2010. Published September 14, 2010. Solid oxide fuel cells SOFC are energy to gas phase transport in porous media, is controlled by optimizing electrode mi- crostructures

  14. Structure of Zirconium-Exchanged H-ZSM5 Prepared by Vapor Exchange of ZrCl4

    E-Print Network [OSTI]

    Iglesia, Enrique

    Structure of Zirconium-Exchanged H-ZSM5 Prepared by Vapor Exchange of ZrCl4 Howard S. Lacheen phase. Zirconium silicates (ZrxSi1-xO2) have been reported to form for several zeolite structures

  15. Proton diffusion pathways and rates in Y-doped BaZrO3 solid oxide electrolyte from quantum mechanics

    E-Print Network [OSTI]

    Goddard III, William A.

    Proton diffusion pathways and rates in Y-doped BaZrO3 solid oxide electrolyte from quantum in the BYZ electrolyte. Indeed, the calculated values bracket the experimental value of Ea=0.44 eV. Based been proposed for the BYZ electrolyte. The thermal librations of BO6 octahedra and uncorrelated thermal

  16. Materials Science and Engineering A 483484 (2008) 607610 Indentation creep study on a Zr-based bulk metallic

    E-Print Network [OSTI]

    Gubicza, Jenõ

    2008-01-01

    to the formation of a quasicrystalline phase. Indentation creep tests were carried out isothermally at the same size quasicrystalline particles on the creep behavior is studied by indentation test. There are onlyMaterials Science and Engineering A 483­484 (2008) 607­610 Indentation creep study on a Zr

  17. Intrinsic Nanostructure in Zr2-xFe4Si16-y (x=0.81, y=6.06)

    SciTech Connect (OSTI)

    Smith, G J; Simonson, J W; Orvis, T; Marques, C; Grose, J E; Kistner-Morris, J J; Wu, L; Cho, Kyuil; Kim, Hyong june; Tanatar, Makariy A; Garlea, V O; Prozorov, Ruslan; Zhu, Y; Aronson, M C

    2014-09-17

    We present a study of the crystal structure and physical properties of single crystals of a new Fe-based ternary compound, Zr2?x Fe4Si16?y(x=0.81,y=6.06). Zr1.19 Fe4Si9.94 is a layered compound, where stoichiometric ?-FeSi2-derived slabs are separated by Zr-Si planes with substantial numbers of vacancies. High resolution transmission electron microscopy (HRTEM) experiments show that these Zr-Si layers consist of 3.5nm domains where the Zrand Si vacancies are ordered within a supercell sixteen times the volume of the stoichiometric cell. Within these domains, the occupancies of the Zr and Si sites obey symmetry rules that permit only certain compositions, none of which by themselves reproduce the average composition found in x-ray diffraction experiments. Magnetic susceptibility and magnetization measurements reveal a small but appreciable number of magnetic moments that remain freely fluctuating to 1.8K, while neutron diffraction confirms the absence of bulk magnetic order with a moment of 0.2? B or larger down to 1.5K. Electrical resistivity measurements find that Zr1.19Fe4Si9.94 is metallic, and the modest value of the Sommerfeld coefficient of the specific heat ? = C/T suggests that quasi-particle masses are not particularly strongly enhanced. The onset of superconductivity at Tc 6K results in a partial resistive transition and a small Meissner signal, although a bulk-like transition is found in the specific heat. Sharp peaks in the ac susceptibility signal the interplay of the normal skin depth and the London penetration depth, typical of a system in which nano-sized superconducting grains are separated by a on-superconducting host. Ultra low field differential magnetic susceptibility measurements reveal the presence of a surprisingly large number of trace magnetic and superconducting phases, suggesting that the Zr-Fe-Si ternary system could be a potentially rich source of new bulk superconductor.

  18. Multinucleon transfer reactions for the {sup 28}Si+{sup 90,94}Zr systems in the region below and near the Coulomb barrier

    SciTech Connect (OSTI)

    Kalkal, Sunil; Mandal, S.; Garg, Ritika; Saxena, Mansi; Goyal, Savi; Verma, S.; Kumar, Suresh; Singh, R. [Department of Physics and Astrophysics, University of Delhi, Delhi (India); Madhavan, N.; Jhingan, A.; Nath, S.; Gehlot, J.; Mohanto, Gayatri [Inter University Accelerator Centre, New Delhi (India); Prasad, E. [Department of Physics, Calicut University, Kerala (India); Sandal, Rohit; Behera, B. R. [Department of Physics, Panjab University, Chandigah (India); Pramanik, U. D. [Saha Institute of Nuclear Physics, Kolkata (India); Sinha, A. K. [UGC-DAE Consortium for Scientific Research, Kolkata (India)

    2011-05-15

    Measurements on multinucleon transfer reactions for {sup 28}Si+{sup 90,94}Zr systems were performed at sub- and near-barrier energies. The fact that {sup 90}Zr has a closed neutron shell (N = 50) and {sup 94}Zr has four neutrons outside the closed shell, allows us to investigate the effects of shell closure and pairing correlation on multinucleon transfer mechanism. The experiment was performed with pulsed {sup 28}Si beam using the Heavy Ion Reaction Analyzer (HIRA) at Inter University Accelerator Centre (IUAC), New Delhi. Based on the Q-value considerations, it turned out that pickup channels were neutron transfer whereas stripping channels were proton transfer. For the {sup 28}Si+{sup 90}Zr system, the values of the slope parameter for two-neutron pickup turned out to be less than that for one-neutron pickup. The values of the slope parameter were almost the same for two-, three-, and four-neutron pickup channels in the case of the {sup 28}Si+{sup 94}Zr system. The transfer probabilities in the case of the {sup 28}Si+{sup 94}Zr system were much larger than those for the {sup 28}Si+{sup 90}Zr system, further supporting the fact that there is a correlation between the transfer channels and sub-barrier fusion cross-section enhancement. An odd-even staggering was observed in the extracted transfer probabilities at the barrier radius implying the role of pairing correlation in transfer reactions.

  19. Titanite petrochronology of the Pamir gneiss domes: Implications for middle to deep crust exhumation and titanite closure to Pb and Zr diffusion

    E-Print Network [OSTI]

    Stearns, MA; Hacker, BR; Ratschbacher, L; Rutte, D; Kylander-Clark, ARC

    2015-01-01

    H. M. Zhan (2008), The geochronology of Taxkorgan alkalicCanada: Implications for U-Pb geochronology and PTt pathfrom Lu-Hf and U-Pb geochronology, and garnet thermometry,

  20. Deposition and characterization of zirconium nitride (ZrN) thin films by reactive magnetron sputtering with linear gas ion source and bias voltage

    SciTech Connect (OSTI)

    Kavitha, A.; Kannan, R. [Department of Physics, University College of Engineering, Anna University, Dindugal-624622 (India); Subramanian, N. Sankara [Department of Physics, Thiagarajar College of Engineering, Madurai -625015, Tamilnadu (India); Loganathan, S. [Ion Plating, Titan Industries Ltd., Hosur - 635126, Tamilnadu (India)

    2014-04-24

    Zirconium nitride thin films have been prepared on stainless steel substrate (304L grade) by reactive cylindrical magnetron sputtering method with Gas Ion Source (GIS) and bias voltage using optimized coating parameters. The structure and surface morphologies of the ZrN films were characterized using X-ray diffraction, atomic microscopy and scanning electron microscopy. The adhesion property of ZrN thin film has been increased due to the GIS. The coating exhibits better adhesion strength up to 10 N whereas the ZrN thin film with bias voltage exhibits adhesion up to 500 mN.

  1. Effect of cerium incorporation into zirconia on the activity ofCu/ZrO2 for methanol synthesis via CO hydrogenation

    SciTech Connect (OSTI)

    Pokrovski, Konstantin A.; Rhodes, Michael D.; Bell, Alexis T.

    2005-08-24

    The effects of Ce incorporation into ZrO2 on the catalyticperformance of Cu/ZrO2 for the hydrogenation of CO have beeninvestigated. A Ce0.3Zr0.7O2 solid solution was synthesized by forcedhydrolysis at low pH. After calcination at 873 K, XRD and Ramanspectroscopy characterization indicated that the Ce0.3Zr0.7O2 had a t''crystal structure. 1.2 wt percent Cu/Ce0.3Zr0.7O2 exhibited H2consumption peaks at low temperature (<473 K) during H2-TPRindicating a significant fraction (~; 70 percent) of Ce4+ is reduced toCe3+. 1.2 wt percent Cu/Ce0.3Zr0.7O2 is 2.7 times more active formethanol synthesis than 1.2 wt percent Cu/m-ZrO2 at 3.0 MPa attemperatures between 473 and 523 K and exhibits a higher selectivity tomethanol. In-situ infrared spectroscopy shows that, analogous toCu/m-ZrO2, the primary surface species on Cu/Ce0.3Zr0.7O2 during COhydrogenation are formate and methoxide species. A shift in the bandposition of the bridged methoxide species indicated that some of thesegroups were bonded to both Zr4+ and Ce3+ cations. For both catalysts, therate-limiting step for methanol synthesis is the reductive elimination ofmethoxide species. The higher rate of methanol synthesis onCu/Ce0.3Zr0.7O2 relative to Cu/m-ZrO2 was primarily due to a ~; 2.4 timeshigher apparent rate constant, kapp, for methoxide hydrogenation, whichis attributed to the higher surface concentration of H atoms on theformer catalyst. The increased capacity of the Ce-containing catalyst isattributed to interactions of H atoms with Ce-O pairs present at thesurface of the oxide phase.

  2. Optical spectroscopy study of the three-dimensional Dirac semimetal ZrTe5

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

    Chen, R. Y.; Gu, G. D.; Zhang, S. J.; Schneeloch, J. A.; Zhang, C.; Li, Q.; Wang, N. L.

    2015-08-05

    Three-dimensional (3D) topological Dirac materials have been under intensive study recently. The layered compound ZrTe5 has been suggested to be one such material as a result of transport and angle-resolved photoemission spectroscopy experiments. Here, we perform infrared reflectivity measurements to investigate the underlying physics of this material. The derived optical conductivity increases linearly with frequency below normal interband transitions, which provides optical spectroscopic proof of a 3D Dirac semimetal. In addition, the plasma edge shifts dramatically to lower energy upon temperature cooling, which might be due to the shrinking of the lattice parameters. Additionally, an extremely sharp peak shows upmore »in the frequency-dependent optical conductivity, indicating the presence of a Van Hove singularity in the joint density of state.« less

  3. Rapid Relaxation and Embrittlement of Zr-based Bulk Metallic Glasses by Electropulsing

    SciTech Connect (OSTI)

    Yiu, P [Department of Materials Science and Engineering, National Taiwan University, Taipei 106, Taiwan; Chen, Y. C. [National Taiwan University of Science & Technology; Chu, J. P. [National Taiwan Ocean University; Chang, S Y [National Chung Hsing University; Bei, Hongbin [ORNL; Jang, J. S.C. [National Central University, Jhongli 32001, Taiwan; Hsueh, C. H. [Department of Materials Science and Engineering, National Taiwan University, Taipei 106, Taiwan

    2013-01-01

    Mechanical relaxation and embrittlement of Zr52.5Cu17.9Ni14.6Al10Ti5 bulk metallic glasses were achieved rapidly by the direct current electropulsing treatment. The temperature profile was recorded by an infrared camera and it was found to be non-uniform in the treated specimen. Specifically, temperatures below the glass transition temperature, near and above the crystallization temperature could be ach- ieved, respectively, at different locations in the same treated specimen. Two sets of nanoindentation were conducted. While the first set investigated the mechanical properties of three individually elec- tropulsed specimens with different conditions, the second set indented a single treated specimen along its temperature gradient. Both sets of indentation revealed that by Joule heating to different tempera- tures, relaxation, embrittlement, and crystallization were significantly accelerated by electrical pulses. Results suggest that electropulsing provides an opportunity to simultaneously achieve plastic forming and mechanical property control of metallic glasses.

  4. Thick Pb(Zr,Ti)O{sub 3} film without substrate

    SciTech Connect (OSTI)

    Lee, Jae-Wung; Park, Chee-Sung; Jo, Ji-Hoon; Kim, Hyoun-Ee [Department of Materials Science and Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of)

    2007-08-13

    In order to fabricate thick PbZr{sub x}Ti{sub 1-x}O{sub 3} (PZT) films for microelectromechanical system applications, the authors introduce a concept of freestanding film without a substrate. PZT films with a thickness of up to 20 {mu}m were deposited on a very thin Pt layer without a substrate by the rf-magnetron sputtering method using a single oxide target. The Pt layer (thickness <1 {mu}m) was obtained by sputtering the Pt on a Si substrate with a carbon layer between them, and subsequently removing the carbon layer by oxidation in air at 400 deg. C. Piezoelectric properties of the film were comparable to those of bulk PZT as a result of the removal of clamping effect of the substrate.

  5. LANL Experience Rolling Zr-Clad LEU-10Mo Foils for AFIP-7

    SciTech Connect (OSTI)

    Hammon, Duncan L.; Clarke, Kester D.; Alexander, David J.; Kennedy, Patrick K.; Edwards, Randall L.; Duffield, Andrew N.; Dombrowski, David E.

    2015-05-29

    The cleaning, canning, rolling and final trimming of Low Enriched Uranium-10 wt. pct. Molybdenum (LEU-10Mo) foils for ATR (Advanced Test Reactor) fuel plates to be used in the AFIP-7 (ATR Full Size Plate In Center Flux Trap Position) experiments are summarized. Six Zr-clad foils were produced from two LEU-10Mo castings supplied to Los Alamos National Laboratory (LANL) by Y-12 National Security Complex. Details of cleaning and canning procedures are provided. Hot- and cold-rolling results are presented, including rolling schedules, images of foils in-process, metallography and local compositions of regions of interest, and details of final foil dimensions and process yield. This report was compiled from the slides for the presentation of the same name given by Duncan Hammon on May 12, 2011 at the AFIP-7 Lessons Learned meeting in Salt Lake City, UT, with Los Alamos National Laboratory document number LA-UR 11-02898.

  6. Physicochemical investigations of carbon nanofiber supported Cu/ZrO{sub 2} catalyst

    SciTech Connect (OSTI)

    Din, Israf Ud E-mail: maizats@petronas.com.my; Shaharun, Maizatul S. E-mail: maizats@petronas.com.my; Subbarao, Duvvuri; Naeem, A.

    2014-10-24

    Zirconia-promoted copper/carbon nanofiber catalysts (Cu?ZrO{sub 2}/CNF) were prepared by the sequential deposition precipitation method. The Herringbone type of carbon nanofiber GNF-100 (Graphite nanofiber) was used as a catalyst support. Carbon nanofiber was oxidized to (CNF-O) with 5% and 65 % concentration of nitric acid (HNO{sub 3}). The CNF activated with 5% HNO{sub 3} produced higher surface area which is 155 m{sup 2}/g. The catalyst was characterized by X-ray Diffraction (XRD), Fourier Transform Infra-Red (FTIR) and N{sub 2} adsorption-desorption. The results showed that increase of HNO{sub 3} concentration reduced the surface area and porosity of the catalyst.

  7. Current scaling of axially radiated power in dynamic hohlraums and dynamic hohlraum load design for ZR.

    SciTech Connect (OSTI)

    Mock, Raymond Cecil; Nash, Thomas J.; Sanford, Thomas W. L.

    2007-03-01

    We present designs for dynamic hohlraum z-pinch loads on the 28 MA, 140 ns driver ZR. The scaling of axially radiated power with current in dynamic hohlraums is reviewed. With adequate stability on ZR this scaling indicates that 30 TW of axially radiated power should be possible. The performance of the dynamic hohlraum load on the 20 MA, 100 ns driver Z is extensively reviewed. The baseline z-pinch load on Z is a nested tungsten wire array imploding onto on-axis foam. Data from a variety of x-ray diagnostics fielded on Z are presented. These diagnostics include x-ray diodes, bolometers, fast x-ray imaging cameras, and crystal spectrometers. Analysis of these data indicates that the peak dynamic radiation temperature on Z is between 250 and 300 eV from a diameter less than 1 mm. Radiation from the dynamic hohlraum itself or from a radiatively driven pellet within the dynamic hohlraum has been used to probe a variety of matter associated with the dynamic hohlraum: the tungsten z-pinch itself, tungsten sliding across the end-on apertures, a titanium foil over the end aperture, and a silicon aerogel end cap. Data showing the existence of asymmetry in radiation emanating from the two ends of the dynamic hohlraum is presented, along with data showing load configurations that mitigate this asymmetry. 1D simulations of the dynamic hohlraum implosion are presented and compared to experimental data. The simulations provide insight into the dynamic hohlraum behavior but are not necessarily a reliable design tool because of the inherently 3D behavior of the imploding nested tungsten wire arrays.

  8. In situ study of the role of substrate temperature during atomic layer deposition of HfO{sub 2} on InP

    SciTech Connect (OSTI)

    Dong, H.; Santosh, K.C.; Qin, X.; Brennan, B.; McDonnell, S.; Kim, J. [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080 (United States)] [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080 (United States); Zhernokletov, D. [Department of Physics, University of Texas at Dallas, Richardson, Texas 75080 (United States)] [Department of Physics, University of Texas at Dallas, Richardson, Texas 75080 (United States); Hinkle, C. L.; Cho, K.; Wallace, R. M. [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080 (United States) [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080 (United States); Department of Physics, University of Texas at Dallas, Richardson, Texas 75080 (United States)

    2013-10-21

    The dependence of the “self cleaning” effect of the substrate oxides on substrate temperature during atomic layer deposition (ALD) of HfO{sub 2} on various chemically treated and native oxide InP (100) substrates is investigated using in situ X-ray photoelectron spectroscopy. The removal of In-oxide is found to be more efficient at higher ALD temperatures. The P oxidation states on native oxide and acid etched samples are seen to change, with the total P-oxide concentration remaining constant, after 10 cycles of ALD HfO{sub 2} at different temperatures. An (NH{sub 4}){sub 2} S treatment is seen to effectively remove native oxides and passivate the InP surfaces independent of substrate temperature studied (200 °C, 250 °C and 300 °C) before and after the ALD process. Density functional theory modeling provides insight into the mechanism of the changes in the P-oxide chemical states.

  9. Phase transition behavior and high piezoelectric properties in lead-free BaTiO3CaTiO3BaHfO3 ceramics

    E-Print Network [OSTI]

    Cao, Wenwu

    ceramics Dali Wang · Zhaohua Jiang · Bin Yang · Shantao Zhang · Mingfu Zhang · Feifei Guo · Wenwu Cao of lead-free (1-x)Ba(Hf0.16Ti0.84)O3­x (Ba0.70Ca0.30)TiO3 (BCHT) ceramics fabricated by the conventional been proposed based on their dielectric behavior. It is found that BHCT ceramics undergo a complicated

  10. Effect of annealing temperature on optical and electrical properties of ZrO{sub 2}?SnO{sub 2} based nanocomposite thin films

    SciTech Connect (OSTI)

    Anitha, V. S., E-mail: jolly2jolly@gmail.com; Lekshmy, S. Sujatha, E-mail: jolly2jolly@gmail.com; Berlin, I. John, E-mail: jolly2jolly@gmail.com; Joy, K., E-mail: jolly2jolly@gmail.com [Thin film Laboratory, Post Graduate and Research Department of Physics, Mar Ivanios College, Thiruvananthapuram 695 015 (India)

    2014-01-28

    Transparent nanocomposite ZrO{sub 2}?SnO{sub 2} thin films were prepared by sol-gel dip-coating technique. Films were annealed at 500°C, 800°C and 1200°C respectively. X-ray diffraction(XRD) spectra showed a mixture of three phases: tetragonal ZrO{sub 2} and SnO{sub 2} and orthorhombic ZrSnO{sub 4}. The grain size of all the three phases' increased with annealing temperature. An average transmittance greater than 85%(in UV-Visible region) is observed for all the films. The band gap for the films decreased from 4.79 eV to 4.62 eV with increase in annealing temperature from 500 to 1200 °C. The electrical resistivity increased with increase in annealing temperature. Such composite ZrO{sub 2}?SnO{sub 2} films can be used in many applications and in optoelectronic devices.

  11. Effect of cerium incorporation into zirconia on the activity of Cu/ZrO2 for methanol synthesis via CO hydrogenation

    E-Print Network [OSTI]

    Pokrovski, Konstantin A.; Rhodes, Michael D.; Bell, Alexis T.

    2005-01-01

    Cerium Incorporation into Zirconia on the Activity of Cu/ZrOhydrogenation to methanol [1-6]. Zirconia has proven to be aon the surface of zirconia to form formate species which

  12. A comparison of crystalline and molten structures of zirconolite (CaZrTi?O?), a potential plutonium wasteform medium, by molecular dynamics simulation and topological analysis

    E-Print Network [OSTI]

    Rich, Sarah Celeste

    2008-01-01

    Molecular dynamics simulations of the ceramic compound zirconolite (CaZrTi?O?), a potential crystalline wasteform host for plutonium, were carried out for ideal and experimental crystalline forms and a simulated molten ...

  13. Microstructural characterization of a thin film ZrN diffusion barrier in an As-fabricated U–7Mo/Al matrix dispersion fuel plate

    SciTech Connect (OSTI)

    Keiser, Dennis D.; Perez, Emmanuel; Wiencek, Tom; Leenaers, Ann; Van den Berghe, Sven

    2015-03-01

    The United States High Performance Research Reactor Fuel Development program is developing low enriched uranium fuels for application in research and test reactors. One concept utilizes U–7 wt.% Mo (U–7Mo) fuel particles dispersed in Al matrix, where the fuel particles are coated with a 1 ?m-thick ZrN coating. The ZrN serves as a diffusion barrier to eliminate a deleterious reaction that can occur between U–7Mo and Al when a dispersion fuel is irradiated under aggressive reactor conditions. To investigate the final microstructure of a physically-vapor-deposited ZrN coating in a dispersion fuel plate after it was fabricated using a rolling process, characterization samples were taken from a fuel plate that was fabricated at 500 °C using ZrN-coated U–7Mo particles, Al matrix and AA6061 cladding. Scanning electron and transmission electron microscopy analysis were performed. Data from these analyses will be used to support future microstructural examinations of irradiated fuel plates, in terms of understanding the effects of irradiation on the ZrN microstructure, and to determine the role of diffusion barrier microstructure in eliminating fuel/matrix interactions during irradiation. The as-fabricated coating was determined to be cubic-ZrN (cF8) phase. It exhibited a columnar microstructure comprised of nanometer-sized grains and a region of relatively high porosity, mainly near the Al matrix. Small impurity-containing phases were observed at the U–7Mo/ZrN interface, and no interaction zone was observed at the ZrN/Al interface. The bonding between the U–7Mo and ZrN appeared to be mechanical in nature. A relatively high level of oxygen was observed in the ZrN coating, extending from the Al matrix in the ZrN coating in decreasing concentration. The above microstructural characteristics are discussed in terms of what may be most optimal for a diffusion barrier in a dispersion fuel plate application.

  14. Energy band alignment of atomic layer deposited HfO{sub 2} oxide film on epitaxial (100)Ge, (110)Ge, and (111)Ge layers

    SciTech Connect (OSTI)

    Hudait, Mantu K.; Zhu Yan [Advanced Devices and Sustainable Energy Laboratory (ADSEL), Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States)

    2013-03-21

    Crystallographically oriented epitaxial Ge layers were grown on (100), (110), and (111)A GaAs substrates by in situ growth process using two separate molecular beam epitaxy chambers. The band alignment properties of atomic layer hafnium oxide (HfO{sub 2}) film deposited on crystallographically oriented epitaxial Ge were investigated using x-ray photoelectron spectroscopy (XPS). Valence band offset, {Delta}E{sub v} values of HfO{sub 2} relative to (100)Ge, (110)Ge, and (111)Ge orientations were 2.8 eV, 2.28 eV, and 2.5 eV, respectively. Using XPS data, variation in valence band offset, {Delta}E{sub V}(100)Ge>{Delta}E{sub V}(111)Ge>{Delta}E{sub V}(110)Ge, was obtained related to Ge orientation. Also, the conduction band offset, {Delta}E{sub c} relation, {Delta}E{sub c}(110)Ge>{Delta}E{sub c}(111)Ge>{Delta}E{sub c}(100)Ge related to Ge orientations was obtained using the measured bandgap of HfO{sub 2} on each orientation and with the Ge bandgap of 0.67 eV. These band offset parameters for carrier confinement would offer an important guidance to design Ge-based p- and n-channel metal-oxide field-effect transistor for low-power application.

  15. Effect of Si substrate on interfacial SiO{sub 2} scavenging in HfO{sub 2}/SiO{sub 2}/Si stacks

    SciTech Connect (OSTI)

    Li, Xiuyan, E-mail: xiuyan@adam.t.u-tokyo.ac.jp; Yajima, Takeaki; Nishimura, Tomonori; Nagashio, Kosuke; Toriumi, Akira [Department of Materials Engineering, The University of Tokyo, 7-3-1 Hongo, Tokyo 113-8656 (Japan)

    2014-11-03

    The scavenging kinetics of an ultra-thin SiO{sub 2} interface layer (SiO{sub 2}-IL) in an HfO{sub 2}/SiO{sub 2}/Si stack is discussed by focusing on the substrate effect in addition to oxygen diffusion. {sup 18}O tracing experiments demonstrate that the O-atom moves from the SiO{sub 2}-IL to the HfO{sub 2} layer during scavenging. SiO{sub 2}-IL scavenging with various substrates (Si, SiC, and sapphire) has been found to be significantly different, which suggests that the Si in the substrate is also necessary to continuously cause the scavenging. Based on these findings and thermodynamic considerations, a kinetic model where oxygen vacancy (V{sub O}) transferred from the HfO{sub 2} reacts with the SiO{sub 2}, which is in contact with the Si-substrate, is proposed for the SiO{sub 2}-IL scavenging.

  16. Formation of the dopant-oxygen vacancy complexes and its influence on the photoluminescence emissions in Gd-doped HfO{sub 2}

    SciTech Connect (OSTI)

    Wang, L. G.; Tu, H. L.; Xiong, Y. H.; Du, J.; Wang, J. W.; Huang, G. J. [General Research Institute for Nonferrous Metals, Beijing 100088 (China); Xiao, W. [General Research Institute for Nonferrous Metals, Beijing 100088 (China); University of Science and Technology Beijing, Beijing 100083 (China)

    2014-09-28

    Rare earth doping is widely used to improve the desired properties of high-k dielectric oxides. However, whether rare earth doping can suppress the formation of oxygen vacancies is still debated. By using the first-principles calculations with the generalized gradient approximation and more advanced hybrid functional, we have investigated the structural and electronic properties of the dopant-oxygen vacancy complexes in Gd-doped HfO{sub 2}. Our calculations indicate that the Gd dopants interacting with oxygen vacancies can substantially shift up the V{sub O} energy states towards the conduction band edge. This together with other effects, such as capturing the localized electrons at the oxygen vacancy by Gd dopants and suppressing the randomicity of oxygen vacancy formation, improves the reliability of the devices made from Gd-doped HfO{sub 2}. Based on our calculated results, we have presented an explanation for the experimentally observed decrease of the V{sub O}-related photoluminescence intensities upon Gd doping in HfO{sub 2}.

  17. Brazing ZrO{sub 2} ceramic to Ti–6Al–4V alloy using NiCrSiB amorphous filler foil: Interfacial microstructure and joint properties

    SciTech Connect (OSTI)

    Cao, J., E-mail: cao_jian@hit.edu.cn [Shandong Provincial Key Laboratory of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209 (China); State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Song, X.G., E-mail: song_xiaoguohit@yahoo.com.cn [Shandong Provincial Key Laboratory of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209 (China); State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Li, C., E-mail: li_chun1989@yahoo.cn [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Zhao, L.Y., E-mail: Zhao_ly@163.com [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Feng, J.C., E-mail: feng_jicai@163.com [Shandong Provincial Key Laboratory of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209 (China); State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China)

    2013-07-15

    Reliable brazing of ZrO{sub 2} ceramic and Ti–6Al–4V alloy was achieved using NiCrSiB amorphous filler foil. The interfacial microstructure of ZrO{sub 2}/Ti–6Al–4V joints was characterized by scanning electron microscope, energy dispersive spectrometer and micro-focused X-ray diffractometer. The effects of brazing temperature on the interfacial microstructure and joining properties of brazed joints were investigated in detail. Active Ti of Ti–6Al–4V alloy dissolved into molten filler metal and reacted with ZrO{sub 2} ceramic to form a continuous TiO reaction layer, which played an important role in brazing. Various reaction phases including Ti{sub 2}Ni, Ti{sub 5}Si{sub 3} and ?-Ti were formed in brazed joints. With an increasing of brazing temperature, the TiO layer thickened gradually while the Ti{sub 2}Ni amount reduced. Shear test indicated that brazed joints tend to fracture at the interface between ZrO{sub 2} ceramic and brazing seam or Ti{sub 2}Ni intermetallic layer. The maximum average shear strength reached 284.6 MPa when brazed at 1025 °C for 10 min. - Graphical Abstract: Interfacial microstructure of ZrO{sub 2}/TC4 joint brazed using NiCrSiB amorphous filler foil was: ZrO{sub 2}/TiO/Ti{sub 2}Ni + ?-Ti + Ti{sub 5}Si{sub 3}/?-Ti/Widmanstätten structure/TC4. - Highlights: • Brazing of ZrO{sub 2} ceramic and Ti-6Al-4V alloy was achieved. • Interfacial microstructure was TiO/Ti{sub 2}Ni + ? + Ti{sub 5}Si{sub 3}/?/Widmanstätten structure. • The formation of TiO produced the darkening effect of ZrO{sub 2} ceramic. • The highest joining strength of 284.6MPa was obtained.

  18. Design of 7 wt.% Y2O3-ZrO2/Mullite Plasma-Sprayed Composite Coatings for Increased Creep Resistance

    E-Print Network [OSTI]

    Trice, Rodney W.

    Design of 7 wt.% Y2O3-ZrO2/Mullite Plasma-Sprayed Composite Coatings for Increased Creep Resistance of the American Ceramic Society #12;2 Abstract Plasma-sprayed stand-alone coatings of 7 wt.% Y2O3-ZrO2 (YSZ three coating types in the as-sprayed condition at stresses from 40-80 MPa and temperatures of 1000

  19. Preparation of Lead Zirconate Titanate (Pb(Zr0.52Ti0.48)O3) by Homogeneous Precipitation and Calcination

    E-Print Network [OSTI]

    Tas, A. Cuneyt

    University, Ankara 06531, Turkey Preparation of phase-pure PZT (Pb(Zr0.52Ti0.48)O3) pow- ders was achieved, Darmstadt, Germany), ZrOCl2 8H2O (99%, Merck, Darmstadt, Germany), and TiCl4 (98%, Merck, Darmstadt, Germany4N2O, 99.5%, Riedel-De Haen AG, Germany) was used as the precipitation agent. (1) Homogeneous

  20. The Department of Energy's Management of the Award of a $150 Million Recovery Act Grant to LG Chem Michigan Inc., OAS-RA-13-10

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankADVANCEDInstallers/ContractorsPhotovoltaicsState of Pennsylvania OAS-RA-L-11-11 SeptemberManagement

  1. The Department of Energy's Weatherization Assistance Program Funded under the American Recovery and Reinvestment Act for the Commonwealth of Virginia, OAS-RA-11-14

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankADVANCEDInstallers/ContractorsPhotovoltaicsState of Pennsylvania OAS-RA-L-11-11RenewableUse

  2. The Department of Energy's Weatherization Assistance Program Funded under the American Recovery and Reinvestment Act for the State of New York, OAS-RA-12-07

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankADVANCEDInstallers/ContractorsPhotovoltaicsState of Pennsylvania OAS-RA-L-11-11RenewableUse

  3. The Department of Energy's Weatherization Assistance Program Funded under the American Recovery and Reinvestment Act for the State of New York, OAS-RA-12-07

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankADVANCEDInstallers/ContractorsPhotovoltaicsState of Pennsylvania OAS-RA-L-11-11RenewableUse

  4. Characterization of self-propagating formation reactions in Ni/Zr multilayered foils using reaction heats, velocities, and temperature-time profiles

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

    Barron, S. C.; Knepper, R.; Walker, N.; Weihs, T. P.

    2011-01-11

    We report on intermetallic formation reactions in vapor-deposited multilayered foils of Ni/Zr with 70 nm bilayers and overall atomic ratios of Ni:Zr, 2 Ni:Zr, and 7 Ni:2 Zr. The sequence of alloy phase formation and the stored energy is evaluated at slow heating rates (~1 K/s) using differential scanning calorimetry (DSC) traces to 725ºC. All three chemistries initially form a Ni-Zr amorphous phase which crystallizes first to the intermetallic NiZr. The heat of reaction to the final phase is 34-36 kJ/mol atom for all chemistries. Intermetallic formation reactions are also studied at rapid heating rates (greater than 105 K/s) inmore »high temperature, self-propagating reactions which can be ignited in these foils by an electric spark. We find that reaction velocities and maximum reaction temperatures (Tmax) are largely independent of foil chemistry at 0.6 ± 0.1 m/s and 1220 ± 50 K, respectively, and that the measured Tmax is more than 200 K lower than predicted adiabatic temperatures (Tad). The difference between Tmax and Tad is explained by the prediction that transformation to the final intermetallic phases occurs after Tmax and results in the release of 20-30 % of the total heat of reaction and a delay in rapid cooling.« less

  5. Characterization of self-propagating formation reactions in Ni/Zr multilayered foils using reaction heats, velocities, and temperature-time profiles

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

    Barron, S. C.; Knepper, R.; Walker, N.; Weihs, T. P.

    2011-01-11

    We report on intermetallic formation reactions in vapor-deposited multilayered foils of Ni/Zr with 70 nm bilayers and overall atomic ratios of Ni:Zr, 2 Ni:Zr, and 7 Ni:2 Zr. The sequence of alloy phase formation and the stored energy is evaluated at slow heating rates (~1 K/s) using differential scanning calorimetry (DSC) traces to 725ºC. All three chemistries initially form a Ni-Zr amorphous phase which crystallizes first to the intermetallic NiZr. The heat of reaction to the final phase is 34-36 kJ/mol atom for all chemistries. Intermetallic formation reactions are also studied at rapid heating rates (greater than 105 K/s) in high temperature, self-propagating reactions which can be ignited in these foils by an electric spark. We find that reaction velocities and maximum reaction temperatures (Tmax) are largely independent of foil chemistry at 0.6 ± 0.1 m/s and 1220 ± 50 K, respectively, and that the measured Tmax is more than 200 K lower than predicted adiabatic temperatures (Tad). The difference between Tmax and Tad is explained by the prediction that transformation to the final intermetallic phases occurs after Tmax and results in the release of 20-30 % of the total heat of reaction and a delay in rapid cooling.

  6. Understanding ferromagnetism and optical absorption in 3d transition metal-doped cubic ZrO{sub 2} with the modified Becke-Johnson exchange-correlation functional

    SciTech Connect (OSTI)

    Boujnah, M.; Zaari, H.; El Kenz, A.; Labrim, H.; Benyoussef, A.; Mounkachi, O.

    2014-03-28

    The electronic structure, magnetic, and optical properties in cubic crystalline phase of Zr{sub 1?x}TM{sub x}O{sub 2} (TM?=?V, Mn, Fe, and Co) at x?=?6.25% are studied using density functional theory with the Generalized Gradient Approximation and the modified Becke-Johnson of the exchange-correlation energy and potential. In our calculations, the zirconia is a p-type semiconductor and has a large band gap. We evaluated the possibility of long-range magnetic order for transition metal ions substituting Zr. Our results show that ferromagnetism is the ground state in V, Mn, and Fe-doped ZrO{sub 2} and have a high value of energy in Mn-doped ZrO{sub 2}. However, in Co-doped ZrO{sub 2}, antiferromagnetic ordering is more stable than the ferromagnetic one. The exchange interaction mechanism has been discussed to explain the responsible of this stability. Moreover, it has been found that the V, Mn, and Fe transition metals provide half-metallic properties considered to be the leading cause, responsible for ferromagnetism. Furthermore, the optical absorption spectra in the TM -doped cubic ZrO{sub 2} are investigated.

  7. Iron-stabilized nanocrystalline ZrO{sub 2} solid solutions: Synthesis by combustion and thermal stability

    SciTech Connect (OSTI)

    Legorreta Garcia, Felipe; Resende, Valdirene Gonzaga de; De Grave, Eddy; Peigney, Alain; Barnabe, Antoine; Laurent, Christophe

    2009-06-03

    The synthesis of Fe{sup 3+}-stabilized zirconia by the nitrate/urea combustion route was investigated. Using several characterization techniques, including X-ray diffraction, field-emission-gun scanning electron microscopy and notably Moessbauer spectroscopy, it was possible to determine the appropriate amount of urea that allows to obtain a totally stabilized Zr{sub 0.9}Fe{sub 0.1}O{sub 1.95} solid solution. The nanocrystalline zirconia solid solution is mostly tetragonal, but the presence of the cubic phase could not be ruled out. An in-depth study of the thermal stability in air showed that the Fe{sup 3+} solubility in the stabilized solid solution starts to decrease at about 875 deg. C which results in the formation of hematite (possibly containing some Zr{sup 4+}) at the surface of the zirconia grains and further provokes the progressive transformation into the monoclinic zirconia phase.

  8. Electron-Transport Properties of Amorphous (Zr0.64ni0.36)1-Xalx Alloys 

    E-Print Network [OSTI]

    BHATNAGAR, AK; PAN, R.; Naugle, Donald G.

    1989-01-01

    .06 ?~x=0.15 ?x=0. 1 0 x=0.20 C; 210- 1.04- OO x =0.25~ . . ::.- -? .~x=0.05 185 . 1.02-. x=0.0~ '- 160 0.1 0.2 0.3 FIG. 2. Room-temperature (300-K) resistivity p as a function of Al concentration x for amorphous (ZrQ 64NiQ 3{j), Al... coefficient 8& for amorphous (ZrQ 64NiQ 36) ) Al . 0 0.05 0.10 0.15 0.20 0.25 0.30 Tcryst (K) 679' 747" 718" 785" 764' 792' 800' T. (K) 2.54' 2.560' 2.68g 2.05' 2.33g 1.62' 1.810 pm (g/cm ) 7.25' 7.10' 6.96' 6.73' 6.53' 6...

  9. Assessment of a mechanistic model in U-Pu-Zr metallic alloy fuel fission-gas behavior simulations

    SciTech Connect (OSTI)

    Yun, D.; Rest, J.; Yacout, A. M.

    2012-07-01

    A mechanistic kinetic rate theory model originally developed for the prediction of fission gas behavior in oxide nuclear fuels under steady-state and transient conditions has been assessed to look at its applicability to model fission gas behavior in U-Pu-Zr metallic alloy fuel. In order to capture and validate the underlying physics for irradiated U-Pu-Zr fuels, the mechanistic model was applied to the simulation of fission gas release, fission gas and fission product induced swelling, and the evolution of the gas bubble size distribution in three different fuel zones: the outer {alpha}-U, the intermediate, and the inner {gamma}-U zones. Due to its special microstructural features, the {alpha}-U zone in U-Pu-Zr fuels is believed to contribute the largest fraction of fission gas release among the different fuel zones. It is shown that with the use of small effective grain sizes, the mechanistic model can predict fission gas release that is consistent with (though slightly lower than) experimentally measured data. These simulation results are comparable to the experimentally measured fission gas release since the mechanism of fission gas transport through the densely distributed laminar porosity in the {alpha}-U zone is analogous to the mechanism of fission gas transport through the interconnected gas bubble porosity utilized in the mechanistic model. Detailed gas bubble size distributions predicted with the mechanistic model in both the intermediate zone and the high temperature {gamma}-U zone of U-Pu-Zr fuel are also compared to experimental measurements from available SEM micrographs. These comparisons show good agreements between the simulation results and experimental measurements, and therefore provide crucial guidelines for the selection of key physical parameters required for modeling these two zones. In addition, the results of parametric studies for several key parameters are presented for both the intermediate zone and the {gamma}-U zone simulations. (authors)

  10. Impact of deformation on the atomic structures and dynamics of a Cu-Zr metallic glass: A molecular dynamics study

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

    Zhang, Y.; Mendelev, M. I.; Wang, C. Z.; Ott, R.; Zhang, F.; Besser, M. F.; Ho, K. M.; Kramer, M. J.

    2014-11-03

    Despite numerous studies on the atomic structures of Cu-Zr metallic glasses (MGs), their inherent structural ordering, e.g., medium-range order (MRO), remains difficult to describe. Specifically lacking is an understanding of how the MRO responds to deformation and the associated changes in atomic mobility. In this paper, we focus on the impact of deformation on MRO and associated effect on diffusion in a well-relaxed Cu64.5Zr35.5 MG by molecular dynamics simulations. The Cu-Zr MG exhibits a larger elastic limit of 0.035 and a yield stress of 3.5 GPa. The cluster alignment method was employed to characterize the icosahedral short-range order (ISRO) andmore »Bergman-type medium-range order (BMRO) in the models upon loading and unloading. From this analysis, we find the disruption of both ISRO and BMRO occurs as the strain reaches about 0.02, well below the elastic limit. Within the elastic limit, the total fractions of ISRO or BMRO can be fully recovered upon unloading. The diffusivity increases six to eight times in regions undergoing plastic deformation, which is due to the dramatic disruption of the ISRO and BMRO. As a result, by mapping the spatial distributions of the mobile atoms, we demonstrate the increase in atomic mobility is due to the extended regions of disrupted ISRO and more importantly BMRO.« less

  11. Impact of deformation on the atomic structures and dynamics of a Cu-Zr metallic glass: A molecular dynamics study

    SciTech Connect (OSTI)

    Zhang, Y.; Mendelev, M. I.; Wang, C. Z.; Ott, R.; Zhang, F.; Besser, M. F.; Ho, K. M.; Kramer, M. J.

    2014-11-03

    Despite numerous studies on the atomic structures of Cu-Zr metallic glasses (MGs), their inherent structural ordering, e.g., medium-range order (MRO), remains difficult to describe. Specifically lacking is an understanding of how the MRO responds to deformation and the associated changes in atomic mobility. In this paper, we focus on the impact of deformation on MRO and associated effect on diffusion in a well-relaxed Cu64.5Zr35.5 MG by molecular dynamics simulations. The Cu-Zr MG exhibits a larger elastic limit of 0.035 and a yield stress of 3.5 GPa. The cluster alignment method was employed to characterize the icosahedral short-range order (ISRO) and Bergman-type medium-range order (BMRO) in the models upon loading and unloading. From this analysis, we find the disruption of both ISRO and BMRO occurs as the strain reaches about 0.02, well below the elastic limit. Within the elastic limit, the total fractions of ISRO or BMRO can be fully recovered upon unloading. The diffusivity increases six to eight times in regions undergoing plastic deformation, which is due to the dramatic disruption of the ISRO and BMRO. As a result, by mapping the spatial distributions of the mobile atoms, we demonstrate the increase in atomic mobility is due to the extended regions of disrupted ISRO and more importantly BMRO.

  12. Research on Pd film deposition rate calculation and simulation based on TiZrV/Pd film coating experiment

    E-Print Network [OSTI]

    Wang, Jie; Xu, Yanhui; Wang, Yong

    2015-01-01

    The vacuum chamber of accelerator storage ring need clean ultra-high vacuum environment. TiZrV getter film which was deposited on interior wall of vacuum chamber, can realize distributed pumping, effectively improve the vacuum degree and reduce the longitudinal gradient. But accumulation of pollutants such as N2, O2, will decrease the adsorption ability of non-evaporable getter (NEG), which leads to the reduction of NEG lifetime. Therefore, NEG thin film coated with a layer of Pd which has high diffusion rate and absorption ability for H2, can extend the service life of NEG, and improve the pumping rate of H2 at the same time. With argon as discharge gas, magnetron sputtering method was adopted to prepare TiZrV-Pd film in long straight pipe. According to the experimental results of the scanning electron microscope (SEM), deposition rates of TiZrV-Pd films were analyzed under different deposition parameters, the magnetic field strength, the gas flow rate, discharge current, discharge voltage and working pressu...

  13. Influence of annealing temperature on electronic and dielectric properties of ZrO{sub 2} thin films on Si

    SciTech Connect (OSTI)

    Uthanna, S.; Kondaiah, P.; Madhavi, V.; Rao, G. Mohan [Department of Physics, Sri Venkateswara University, Tirupati - 517 502 (India); Department of Instrumentation and Applied Physics, Indian Institute of Sciences, Bangalore - 560 012 (India)

    2012-06-25

    Zirconium oxide (ZrO{sub 2}) films were deposited on (100) silicon substrates by DC reactive magnetron sputtering of zirconium target at an oxygen partial pressure of 6 Multiplication-Sign 10{sup -2} Pa. The as-deposited films were annealed in air for 1 hour at different temperatures in the range 773 - 1173 K. The influence of annealing temperature on the structural properties of ZrO{sub 2} films and the electrical properties like Capacitance-Voltage and Current-Voltage of the capacitors of the type Al/ZrO{sub 2}/p-Si were studied. The capacitance and dielectric constant of the capacitors were found to increase with increase in annealing temperature from 773 to 973 K, however, with further increase in annealing temperature to 1173 K they were found to decrease. In addition, the leakage current density was decreased from 1 Multiplication-Sign 10{sup -6} to 4 Multiplication-Sign 10{sup -7} A/cm{sup 2} at 1V gate bias voltage and the electrical conduction mechanism was dominated by Schottky emission for all the films in lower electric fields.

  14. Ab initio molecular dynamics simulations of properties of a-Al2O3 /vacuum and a-ZrO2 /vacuum vs a-Al2O3/Ge,,100...,,21...

    E-Print Network [OSTI]

    Kummel, Andrew C.

    -Al2O3/Ge,,100...,,2Ã1... and a-ZrO2/Ge,,100...,,2Ã1... interfaces Evgueni A. Chagarova and Andrew C The local atomic structural properties of a-Al2O3, a-ZrO2 vacuum/oxide surfaces, and a-Al2O3/Ge 100 2 1 , a-ZrO2/Ge 100 2 1 oxide/semiconductor interfaces were investigated by density-functional theory DFT

  15. ANNUITY(RA) RETIREMENTANNUITY

    E-Print Network [OSTI]

    Subramanian, Venkat

    (SRA)/GROUP SUPPLEMENTAL RETIREMENTANNUITY (GSRA) Contributions accepted from . . . Your employer, employee salary reduction (pre-tax)*, and employee salary deduction (after-tax) Your employer, employee salary reduction (pre-tax)*, and employee salary deduction (after-tax) Additional employee salary reduction only Some

  16. Microsoft Word - Ra-15

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i nAand DOE SafetyofDepartment. " 21 ran

  17. KCP R.A'S

    National Nuclear Security Administration (NNSA)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield Municipal GasAdministration Medal01 Sandia NationalSecurityNuclearH-canyon |I 14/%2A en DOE/NNSA

  18. Four-point-bending-fatigue behavior of the Zr-based Vitreloy 105 bulk metallic glass

    SciTech Connect (OSTI)

    Morrison, M. L. [University of Tennessee, Knoxville (UTK); Buchanan, R. A. [University of Tennessee, Knoxville (UTK); Liaw, Peter K [University of Tennessee, Knoxville (UTK); Green, B. A. [University of Tennessee, Knoxville (UTK); Wang, G Y [University of Tennessee, Knoxville (UTK); Liu, Chain T [ORNL; Horton Jr, Joe A [ORNL

    2007-01-01

    The purpose of this study was to make a direct comparison between four-point-bending and uniaxial fatigue tests with the Zr{sub 52.5}Cu{sub 17.9}Ni{sub 14.6}Al{sub 10.0}Ti{sub 5.0} (at.%) BMG alloy (Vitreloy 105). The fatigue lifetimes in four-point bending were found to be greater than those reported in uniaxial testing. However, the fatigue-endurance limit found in four-point bending was slightly less than that reported for uniaxial fatigue. Thus, the significant differences between fatigue studies in the literature are not likely due to this difference in testing geometry. On the contrary, the fatigue lifetimes were found to be highly dependent upon surface defects and material quality. The four-point-bending-fatigue performance of the Vit 105 alloy was found to be greater than most BMGs and similar to the 300 M high-strength steel and other crystalline alloys in spite of not being 'perfectly amorphous.' Due to the detrimental effects of these inhomogeneities and wear at the supporting pins, this fatigue behavior can be assumed to be a conservative estimate of the potential fatigue performance of a perfectly amorphous and homogeneous BMG.

  19. Wettability of brazing alloys on molybdenum and TZM (Mo-Ti-Zr alloy)

    SciTech Connect (OSTI)

    McDonald, M.M.; Keller, D.L.; Heiple, C.R.; Hofmann, W.E.

    1988-01-01

    Vacuum brazing studies have been performed on molybdenum and TZM (0.5Ti-0.08Zr-Mo). Wettability tests have been conducted for nineteen braze metal filler alloys on molybdenum and thirty-two braze metal filler alloys on TZM over a wide range of temperatures. A wetting index, which is a function of contact angle and braze alloy contact area, was determined for each filler alloy at each brazing temperature. The nature and extent of interaction between the brazing alloys and the base metals was analyzed by conventional metallography, scanning-electron microscopy, and electron microprobe analysis. A comparison is made between the behavior of filler alloys on molybdenum and TZM -- filler alloys consistently exhibited less wettability on TZM than on molybdenum. The lower wettability of TZM is believed to be due to a small amount of titanium in the surface oxide on TZM. Cracking was observed in the base metal under some of the high temperature braze deposits. The cracking is shown to arise from liquid metal embrittlement from nickel in the high temperature braze alloys. 7 refs., 11 figs., 2 tabs.

  20. Origin of high Li? conduction in doped Li?La?Zr?O?? garnets

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

    Chen, Yan; Rangasamy, Ezhiylmurugan; Liang, Chengdu; An, Ke

    2015-08-06

    Substitution of a native ion in the crystals with a foreign ion that differs in valence (aliovalent doping) has been widely attempted to upgrade solid-state ionic conductors for various charge carriers including O²?, H?, Li?, Na?, etc. The doping helps promote the high-conductive framework and dredge the tunnel for fast ion transport. The garnet-type Li?La?Zr?O?? (LLZO) is a fast Li? solid conductor, which received much attention as an electrolyte candidate for all-solid-state lithium ion batteries, showing great potential to offer high energy density and minimize battery safety concerns to meet extensive applications in large energy storage systems such as thosemore »for electric vehicles and aerospace. In the Li-stuffed garnet framework of LLZO, the 3D pathway formed by the incompletely occupied tetrahedral sites bridged by a single octahedron enables the superior Li? conductivity. For optimal performance, many aliovalent-doping efforts have been made throughout metal elements (Al³?, Ta??) and metalloid elements (Ga³?, Te??) in the periodic table with various valences to stabilize the high-conductive phase and increase the Li vacancy concentration.« less

  1. Stress-corrosion fatigue-crack growth in a Zr-based bulk amorphousmetal

    SciTech Connect (OSTI)

    Schroeder, V.; Ritchie, R.O.

    2005-09-21

    Electrochemical and mechanical experiments were conducted to analyze the environmentally-influenced cracking behavior of a bulk amorphous metal, Zr41.2Ti13.8Cu12.5Ni10Be22.5. This study was motivated by a scientific interest in mechanisms of fatigue-crack propagation in an amorphous metal, and by a practical interest in the use of this amorphous metal in applications that take advantage of its unique properties, including high specific strength, large elastic strains and low damping. The objective of the work was to determine the rate and mechanisms of subcritical crack growth in this metallic glass in an aggressive environment. Specifically, fatigue-crack propagation behavior was investigated at a range of stress intensities in air and aqueous salt solutions by examining the effects of loading cycle, stress-intensity range, solution concentration, anion identity, solution de-aeration, and bulk electrochemical potential. Results indicate that crack growth in aqueous solution in this alloy is driven by a stress-assisted anodic reaction at the crack tip. Rate-determining steps for such behavior are reasoned to be electrochemical, stress-dependent reaction at near-threshold levels, and mass transport at higher (steady-state) growth rates.

  2. Origin of high Li? conduction in doped Li?La?Zr?O?? garnets

    SciTech Connect (OSTI)

    Chen, Yan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rangasamy, Ezhiylmurugan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Liang, Chengdu [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); An, Ke [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-01-01

    Substituting a native ion in the crystals with a foreign ion that has a difference in valence, termed as aliovalent doping, has been widely attempted to upgrade solid-state ionic conductors for various charge carriers including O²?, H?, Li?, Na?, and so forth.(1-4) The doping aids to promote the high-conductive framework and dredge the tunnel for fast ion transport. The garnet-type Li?La?Zr?O?? (LLZO) is a fast Li? solid conductor, which received vast attention as an electrolyte candidate for all-solid-state lithium ion batteries, showing great potential to offer high energy density and minimize battery safety concerns to meet extensive applications in large energy storage systems such as electric vehicles and aerospace.(5-8) In the Li-stuffed garnet framework of LLZO, the 3D pathway formed through the incompletely occupied tetrahedral sites bridged by a single octahedron enables the superior Li? conductivity.(9, 10) For the purpose of optimal performance, many efforts of aliovalent doping have been made throughout metal elements (Al³?, Ta??) and metalloid elements (Ga³?, Te??) in the periodic table with various valences(11-14) to stabilize the high-conductive phase and increase the Li vacancy concentration.(7, 10, 15)

  3. Formation of a shock deformation induced {omega} phase in Zr 20 Nb alloy

    SciTech Connect (OSTI)

    Dey, G.K.; Tewari, R.; Banerjee, S. . E-mail: sbanerji@magnum.barc.ernet.in; Jyoti, G.; Gupta, S.C.; Joshi, K.D.; Sikka, S.K.

    2004-10-18

    The formation of a plate shaped {omega} phase in Zr-Nb alloy after shock deformation has been studied with a view to ascertaining the nature of this transformation. The orientation relationship between the {beta} and the {omega} lattices was {l_brace}111{r_brace}{sub {beta}}//(0001){sub {omega}} and <11-bar 0>{beta}//<112-bar 0>{omega} which is identical to that seen in case of {omega} phase forming in this alloy on thermal treatment. The experimentally determined habit plane of the plate shaped {omega} phase has been compared with that predicted from the phenomenological theory of martensite formation. A mechanism of transformation involving shear on the <112> planes has been considered. The importance of mechanical instability of the {beta} phase in bringing about this transformation has been investigated. The mechanism of initiation of {omega} transformation has been ascertained by high resolution electron microscopy (HREM) of the {beta} lattice and compared with that happening during {omega} formation in the same alloy by thermal treatment.

  4. Synthesis, crystal structure, and properties of the rhombohedral modification of the thiospinel CuZr{sub 1.86(1)}S{sub 4}

    SciTech Connect (OSTI)

    Dong, Yongkwan; McGuire, Michael A.; Yun, Hoseop; DiSalvo, Francis J.

    2010-03-15

    The rhombohedral modification of the thiospinel, CuZr{sub 1.86(1)}S{sub 4}, has been synthesized by the reaction of the constituent elements in an alkali metal halide flux and structurally characterized by single crystal X-ray diffraction techniques. The title compound crystallizes in the rhombohedral space group D{sub 3d}{sup 5}-R3-barm (no. 166, a=7.3552(2) A, c=35.832(2) A, V=1678.76(13) A{sup 3}, Z=12, and R/wR=0.0239/0.0624). The structure is composed of close packed S layers, with a stacking order of ...ABCBCABABCACAB....along the c axis. The Zr and Cu atoms occupy the octahedral and tetrahedral holes between S layers, respectively. Three different kinds of S-M-S layers exist in the structure: layer I has fully occupied Zr and Cu sites, layer II has fully occupied Zr sites but no Cu, and layer III has partially occupied Zr and fully occupied Cu sites. Transport and optical properties indicate that the title compound is a small band gap (1.26 eV) n-type semiconductor. - Graphical abstract: The projected view of the rhombohedral modification, CuZr{sub 1.86(1)}S{sub 4}, down the [100] direction. Large letters denote the packing sequence of the S atoms (yellow circles) along the c axis. Zr (black circles) and Cu (red circles) atoms occupy the octahedral and tetrahedral holes, respectively, between close packed S layers.

  5. Looking for footprint of bulk metallic glass in electronic and phonon heat capacities of Cu{sub 55}Hf{sub 45?x}Ti{sub x} alloys

    SciTech Connect (OSTI)

    Remenyi, G.; Biljakovi?, K.; Starešini?, D.; Dominko, D.; Risti?, R.; Babi?, E.; Figueroa, I. A.; Davies, H. A.

    2014-04-28

    We report on the heat capacity investigation of Cu{sub 55}Hf{sub 45?x}Ti{sub x} metallic glasses. The most appropriate procedure to estimate low temperature electronic and phonon contributions has been determined. Both contributions exhibit monotonous Ti concentration dependence, demonstrating that there is no relation of either the electron density of states at the Fermi level or the Debye temperature to the increased glass forming ability in the Ti concentration range x?=?15–30. The thermodynamic parameters (e.g., reduced glass temperature) remain better indicators in assessing the best composition for bulk metallic glass formation.

  6. Synthesis, Crystal Structure, and Properties of the Rhomboheral Modification of the Thiospinel CuZr1.86(1)S4

    SciTech Connect (OSTI)

    Dong, Yongkwan; McGuire, Michael A; Hoseop, Yun; DiSalvo, Francis J.

    2009-01-01

    The rhombohedral modification of the thiospinel, CuZr{sub 1.86(1)}S{sub 4}, has been synthesized by the reaction of the constituent elements in an alkali metal halide flux and structurally characterized by single crystal X-ray diffraction techniques. The title compound crystallizes in the rhombohedral space group D{sub 3d}{sup 5}-R{bar 3}m (166, a=7.3552(2) {angstrom}, c=35.832(2) {angstrom}, V=1678.76(13) {angstrom}{sup 3}, Z=12, and R/wR=0.0239/0.0624). The structure is composed of close packed S layers, with a stacking order of ABCBCABABCACAB along the c axis. The Zr and Cu atoms occupy the octahedral and tetrahedral holes between S layers, respectively. Three different kinds of S-M-S layers exist in the structure: layer I has fully occupied Zr and Cu sites, layer II has fully occupied Zr sites but no Cu, and layer III has partially occupied Zr and fully occupied Cu sites. Transport and optical properties indicate that the title compound is a small band gap (1.26 eV) n-type semiconductor.

  7. Localization of vacancies and mobility of lithium ions in Li{sub 2}ZrO{sub 3} as obtained by {sup 6,7}Li NMR

    SciTech Connect (OSTI)

    Baklanova, Ya. V., E-mail: baklanovay@ihim.uran.ru [Institute of Solid State Chemistry, Ural Branch of the Russian Academy of Sciences, 91 Pervomaiskaya str., 620990 Ekaterinburg (Russian Federation); Arapova, I. Yu.; Buzlukov, A.L.; Gerashenko, A.P.; Verkhovskii, S.V.; Mikhalev, K.N. [Institute of Metal Physics, Ural Branch of the Russian Academy of Sciences, 18 Kovalevskaya str., 620990 Ekaterinburg (Russian Federation); Denisova, T.A.; Shein, I.R.; Maksimova, L.G. [Institute of Solid State Chemistry, Ural Branch of the Russian Academy of Sciences, 91 Pervomaiskaya str., 620990 Ekaterinburg (Russian Federation)

    2013-12-15

    The {sup 6,7}Li NMR spectra and the {sup 7}Li spin–lattice relaxation rate were measured on polycrystalline samples of Li{sub 2}ZrO{sub 3}, synthesized at 1050 K and 1300 K. The {sup 7}Li NMR lines were attributed to corresponding structural positions of lithium Li1 and Li2 by comparing the EFG components with those obtained in the first-principles calculations of the charge density in Li{sub 2}ZrO{sub 3}. For both samples the line width of the central {sup 7}Li transition and the spin–lattice relaxation time decrease abruptly at the temperature increasing above ?500 K, whereas the EFG parameters are averaged (??{sub Q}?=42 (5) kHz) owing to thermally activated diffusion of lithium ions. - Graphical abstract: Path of lithium ion hopping in lithium zirconate Li{sub 2}ZrO{sub 3}. - Highlights: • Polycrystalline samples Li{sub 2}ZrO{sub 3} with monoclinic crystal structure synthesized at different temperatures were investigated by {sup 6,7}Li NMR spectroscopy. • Two {sup 6,7}Li NMR lines were attributed to the specific structural positions Li1 and Li2. • The distribution of vacancies was clarified for both lithium sites. • The activation energy and pathways of lithium diffusion in Li{sub 2}ZrO{sub 3} were defined.

  8. Hf-irJ

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield Municipal Gas &SCE-SessionsSouthReport for the t-) S/,,5 'a C O M P R E H E N SGwen Nu+'.nop-s'

  9. Excitation functions of the natTa(p,x)178m2Hf and natW(p,x)178m2Hf reactions at energies up to 2600 MeV

    SciTech Connect (OSTI)

    Titarenko, Yu. E.; Batyaev, V. F.; Pavlov, K. V.; Titarenko, A. Yu.; Zhivun, V. M.; Chauzova, M. V.; Ignatyuk, A. V.; Mashnik, Stepan Georgievich; Leray, S.; Boudard, A.; David, J. -C.; Mancusi, D.; Cugnon, J.; Yariv, Y.; Nishihara, K.; Matsuda, N.; Kumawat, H.; Stankovskiy, A. Yu.

    2015-04-29

    Due to potential level of energy intensity 178m2Hf is an extremely interesting isomer. One possible way to produce this isomer is irradiation of natTa or natW samples with high energy protons. Irradiation of natTa or natW samples performed for other purposes provides an opportunity to study the corresponding reactions. This paper presents the 178m2Hf independent production cross sections for both targets measured by the gamma-ray spectrometry method. The reaction excitation functions have been obtained for the proton energies from 40 up to 2600 MeV. The experimental results were compared with calculations by various versions of the intranuclear cascade model in the well-known codes: ISABEL, Bertini, INCL4.5+ABLA07, PHITS, CASCADE07 and CEM03.02. The isomer ratio for the natTa(p,x) 178m2Hf reaction is evaluated on the basis of the available data.

  10. The Department of Energy's Weatherization Assistance Program under the American Recovery and Reinvestment Act in the State of Missouri (OAS-RA-11-11)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankADVANCEDInstallers/ContractorsPhotovoltaicsState of Pennsylvania OAS-RA-L-11-11RenewableUseU.S.Missouri

  11. Analysis of wear track and debris of stir cast LM13/Zr composite at elevated temperatures

    SciTech Connect (OSTI)

    Panwar, Ranvir Singh, E-mail: ranvir.panwar@thapar.edu; Pandey, O.P., E-mail: oppandey@thapar.edu

    2013-01-15

    Particulate reinforced aluminum metal matrix composite is in high demand in automobile industry where the operational conditions vary from low to high temperature. In order to understand the wear mode at elevated temperature, this study was planned. For this purpose we developed a metal matrix composite containing aluminum alloy (LM13) as matrix and zircon sand as particulate reinforcement by stir casting process. Different amounts of zircon sand (5, 10, 15 and 20 wt.%) were incorporated in the matrix to study the effect of reinforcement on the wear resistance. Dispersion of zircon sand particles in the matrix was confirmed by using optical microscopy. Sliding wear tests were done to study the durability of the composite with respect to the base alloy. The effects of load and temperature on wear behavior from room temperature to 300 Degree-Sign C were studied to understand the wear mechanism deeply. Surface morphology of the worn surfaces after the wear tests as well as wear debris was observed under scanning electron microscope. Mild to severe wear transition was noticed in tests at high temperature and high load. However, there is interesting change in wear behavior of the composite near the critical temperature of the composite. All the observed behavior has been explained with reference to the observed microstructure of the wear track and debris. - Highlights: Black-Right-Pointing-Pointer Good interfacial bonding between zircon sand particles and Al matrix was observed. Black-Right-Pointing-Pointer The effect of temperature on the wear behavior of LM13/Zr composites was studied. Black-Right-Pointing-Pointer Wear resistance of the composite was improved with addition of zircon sand. Black-Right-Pointing-Pointer Transition temperature from mild to severe wear also improved in composite. Black-Right-Pointing-Pointer SEM analysis of the tracks and debris was done to establish wear mechanism.

  12. Negative Thermal Expansion in ZrW{sub 2}O{sub 8}: Mechanisms, Rigid Unit Modes, and Neutron Total Scattering

    SciTech Connect (OSTI)

    Tucker, Matthew G. [Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ (United Kingdom); ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX (United Kingdom); Goodwin, Andrew L.; Dove, Martin T. [Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ (United Kingdom); Keen, David A. [Physics Department, Oxford University, Clarendon Laboratory, Parks Road, Oxford OX1 3PU (United Kingdom); ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX (United Kingdom); Wells, Stephen A. [Biological Physics, Bateman Physical Sciences Building, Arizona State University, Tempe, Arizona 85287-1504 (United States); Evans, John S.O. [Department of Chemistry, University Science Laboratories, South Road, Durham DH1 3LE (United Kingdom)

    2005-12-16

    The local structure of the low-temperature ordered phase of the negative thermal expansion (NTE) material ZrW{sub 2}O{sub 8} has been investigated by reverse Monte Carlo (RMC) modeling of neutron total scattering data. We obtain, for the first time, quantitative measurements of the extent to which the WO{sub 4} and ZrO{sub 6} polyhedra move as rigid units, and we show that these values are consistent with the predictions of rigid unit mode theory. We suggest that rigid unit modes are associated with the NTE. Our results do not support a recent interpretation of x-ray-absorption fine structure spectroscopy data in terms of a larger rigid structural component involving the Zr-O-W linkage.

  13. Germanium-induced stabilization of a very high-k zirconia phase in ZrO{sub 2}/GeO{sub 2} gate stacks

    SciTech Connect (OSTI)

    Tsipas, P.; Volkos, S. N.; Sotiropoulos, A.; Galata, S. F.; Mavrou, G.; Tsoutsou, D.; Panayiotatos, Y.; Dimoulas, A.; Marchiori, C.; Fompeyrine, J.

    2008-08-25

    Electrical data on ZrO{sub 2}/GeO{sub 2} stacks prepared by atomic oxygen beam deposition on Ge at 225 deg. C reveal a relatively weak dependence of the stack equivalent oxide thickness upon the ZrO{sub 2} thickness. This trend points to a very high zirconia dielectric permittivity (k) value which is estimated to be around 44. This is indicative of zirconia crystallization into a tetragonal phase which is also supported by x-ray diffraction data. X-ray photoelectron spectroscopy analysis is in line with the assumption that due to a finite GeO{sub 2} decomposition, Ge is incorporated into the growing ZrO{sub 2}, thus, stabilizing the high-k tetragonal phase.

  14. Dispersion of UO{sub 2}F{sub 2} aerosol and HF vapor in the operating floor during winter ventilation at the Paducah Gaseous Diffusion Plant

    SciTech Connect (OSTI)

    Kim, S.H.; Chen, N.C.J.; Taleyarkhan, R.P.; Keith, K.D.; Schmidt, R.W. [Oak Ridge National Lab., TN (United States); Carter, J.C. [J.C. Carter Associates, Inc., Knoxville, TN (United States)

    1996-12-30

    The gaseous diffusion process is currently employed at two plants in the US: the Paducah Gaseous Diffusion Plant and the Portsmouth Gaseous Diffusion Plant. As part of a facility-wide safety evaluation, a postulated design basis accident involving large line-rupture induced releases of uranium hexafluoride (UF{sub 6}) into the process building of a gaseous diffusion plant (GDP) is evaluated. When UF{sub 6} is released into the atmosphere, it undergoes an exothermic chemical reaction with moisture (H{sub 2}O) in the air to form vaporized hydrogen fluoride (HF) and aerosolized uranyl fluoride (UO{sub 2}F{sub 2}). These reactants disperse in the process building and transport through the building ventilation system. The ventilation system draws outside air into the process building, distributes it evenly throughout the building, and discharges it to the atmosphere at an elevated temperature. Since air is recirculated from the cell floor area to the operating floor, issues concerning in-building worker safety and evacuation need to be addressed. Therefore, the objective of this study is to evaluate the transport of HF vapor and UO{sub 2}F{sub 2} aerosols throughout the operating floor area following B-line break accident in the cell floor area.

  15. High quality HfO{sub 2}/p-GaSb(001) metal-oxide-semiconductor capacitors with 0.8?nm equivalent oxide thickness

    SciTech Connect (OSTI)

    Barth, Michael; Datta, Suman; Bruce Rayner, G.; McDonnell, Stephen; Wallace, Robert M.; Bennett, Brian R.; Engel-Herbert, Roman

    2014-12-01

    We investigate in-situ cleaning of GaSb surfaces and its effect on the electrical performance of p-type GaSb metal-oxide-semiconductor capacitor (MOSCAP) using a remote hydrogen plasma. Ultrathin HfO{sub 2} films grown by atomic layer deposition were used as a high permittivity gate dielectric. Compared to conventional ex-situ chemical cleaning methods, the in-situ GaSb surface treatment resulted in a drastic improvement in the impedance characteristics of the MOSCAPs, directly evidencing a much lower interface trap density and enhanced Fermi level movement efficiency. We demonstrate that by using a combination of ex-situ and in-situ surface cleaning steps, aggressively scaled HfO{sub 2}/p-GaSb MOSCAP structures with a low equivalent oxide thickness of 0.8?nm and efficient gate modulation of the surface potential are achieved, allowing to push the Fermi level far away from the valence band edge high up into the band gap of GaSb.

  16. Ir-based alloys for ultra-high temperature applications

    DOE Patents [OSTI]

    Liu, Chain T.; George, Easo P.; Bloom, Everett E.

    2006-01-03

    An alloy composition includes, in atomic percent: about 1 to about 10% of at least one element selected from the group consisting of Zr and Hf, balance Ir.

  17. Vertical Profiles Of {sup 226}Ra, {sup 232}Th And {sup 40}K Activities In Rocks From The Irati Formation Of The Parana Sedimentary Basin, Southern Brazil

    SciTech Connect (OSTI)

    Ferreira, Ademar de O.; Bastos, Rodrigo O.; Appoloni, Carlos R. [Laboratorio de Fisica Nuclear Aplicada-Departamento de Fisica-CCE Universidade Estadual de Londrina-Campus Universitario Rodovia Celso Garcia Cid s/n, Cx. Postal 6001 86051-990 Londrina (Puerto Rico)

    2008-08-07

    Naturally occurring radioisotopes are present in different concentrations in sedimentary rocks, reflecting the origin of the sediments, the depositional environment, and more recent events such as weathering and erosion. Using a high-resolution {gamma}-ray spectrometry methodology, sedimentary rocks were measured to assess the concentration activities of the natural radioisotopes. The surveyed rocks are from the Irati formation in the Parana sedimentary basin, which are exposed by an abandoned, open-pit limestone mine, in the city of Sapopema, southern Brazil. The exposed vertical profile is 5 m, and its stratigraphy is represented by an alternation of limestone and bituminous shale (layers being a few decimeters thick), and some millimeter rhythm layers with limestone and bituminous shale laminas. Eleven samples were collected along this profile, each of them dried in the open air during 48 hours, sieved through 4 mm mesh and sealed in cylindrical recipients. Measurements were accomplished using a 66% relative efficiency HPGE detector connected to a standard gamma ray spectrometry electronic chain. The detector efficiency in the range of 60 to 1800 keV was carried out with the certified IAEA-385 sediment sample. The Lower Limit of Detection (LLD) to the system is 2.40 Bq{center_dot}kg{sup -1} for {sup 226}Ra, 1.84 Bq{center_dot}kg{sup -1} for {sup 232}Th and 4.20 Bq{center_dot}kg{sup -1} for {sup 40}K. Activity concentrations were determined for {sup 226}Ra (from 16.22 to 151.55 Bq{center_dot}kg{sup -1}), {sup 232}Th (from 2.93 to 56.12 Bq{center_dot}kg{sup -1}) and {sup 40}K (from 38.45 to 644.63 Bq{center_dot}kg{sup -1}). The layers enriched with organic matter presented the higher values of activity. The measured concentrations of the natural radioisotopes were lower for limestone samples (average values and respective deviations were 22.81{+-}0.22 Bq{center_dot}kg{sup -1} for {sup 226}Ra, 4.21{+-}0.07 Bq{center_dot}kg{sup -1} for {sup 232}Th, and 50.11{+-}0.82 Bq{center_dot}kg{sup -1} for {sup 40}K). Higher concentrations were measured for the bituminous shale samples (average values and respective deviations were 108.10{+-}12.17 Bq{center_dot}kg{sup -1} for {sup 226}Ra, 43.69{+-}0.30 Bq{center_dot}kg{sup -1} for {sup 232}Th, and 465.82{+-}3.99 Bq{center_dot}kg{sup -1} for {sup 40}K). The concentrations were intermediate for the rhythmite samples (average values and respective deviations were 50.69{+-}1.09 Bq{center_dot}kg{sup -1} for {sup 226}Ra, 7.63{+-}0.21 Bq{center_dot}kg{sup -1} for {sup 232}Th, and 85.96{+-}2.47 Bq{center_dot}kg{sup -1} for {sup 40}K). As the analyzed rocks are raw materials for the ceramic, cement and soil correction compound industries, the results of this work furnish data to estimate the contribution of these products to the general public's radiation exposure.

  18. Impact of Zr metal and coking reactions on the ex-vessel source term predictions of CORCON/VANESA

    SciTech Connect (OSTI)

    Lee, M.; Davis, R.E.; Khatib-Rahbar, M.

    1987-01-01

    During a core meltdown accident in a LWR, molten core materials (corium) could leave the reactor vessel and interact with concrete. In this paper, the impact of the zirconium content of the corium pool and the coking reaction on the release of fission products are quantified using CORCON/Mod2 and VANESA computer codes. Detailed calculations show that the total aerosol generation is proportional to the zirconium content of the corium pool. Among the twelve fission product groups treated by the VANESA code, CsI, Cs/sub 2/O and Nb/sub 2/O/sub 5/ are completely released over the course of the core/concrete interaction, while an insignificant quantity of Mo, Ru and ZrO/sub 2/ are predicted to be released. The release of BaO, SrO and Ce/sub 2/O increase, while the releases of Te and La/sub 2/O/sub 3/ are relatively unaffected by the Zr content of the corium pool. The impact of the coking reaction on the radionuclide release and aerosol production was found to be insignificant.

  19. Laser shock peening on Zr-based bulk metallic glass and its effect on plasticity: Experiment and modeling

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

    Cao, Yunfeng; Xie, Xie; Antonaglia, James; Winiarski, Bartlomiej; Wang, Gongyao; Shin, Yung C.; Withers, Philip J.; Dahmen, Karin A.; Liaw, Peter K.

    2015-05-20

    The Zr-based bulk metallic glasses (BMGs) are a new family of attractive materials with good glass-forming ability and excellent mechanical properties, such as high strength and excellent wear resistance, which make them candidates for structural and biomedical materials. Although the mechanical behavior of BMGs has been widely investigated, their deformation mechanisms are still poorly understood. In particular, their poor ductility significantly impedes their industrial application. In the present work, we show that the ductility of Zr-based BMGs with nearly zero plasticity is improved by a laser shock peening technique. Moreover, we map the distribution of laser-induced residual stresses via themore »micro-slot cutting method, and then predict them using a three dimensional finite-element method coupled with a confined plasma model. Reasonable agreement is achieved between the experimental and modeling results. The analysis of serrated flow reveals plentiful and useful information of the underlying deformation process. As a result, our work provides an easy and effective way to extend the ductility of intrinsically-brittle BMGs, opening up wider applications of these materials.« less

  20. Collapse of ferromagnetism in itinerant-electron system: A magnetic, transport properties, and high pressure study of (Hf,Ta)Fe{sub 2} compounds

    SciTech Connect (OSTI)

    Diop, L. V. B. Isnard, O.; Kastil, J.; Arnold, Z.; Kamarad, J.

    2014-10-28

    The magnetism and transport properties were studied for Laves (Hf,Ta)Fe{sub 2} itinerant-electron compounds, which exhibit a temperature-induced first-order transition from the ferromagnetic (FM) to the antiferromagnetic (AFM) state upon heating. At finite temperatures, the field-induced metamagnetic phase transition between the AFM and FM has considerable effects on the transport properties of these model metamagnetic compounds. A large negative magnetoresistance of about 14% is observed in accordance with the metamagnetic transition. The magnetic phase diagram is determined for the Laves Hf{sub 1?x}Ta{sub x}Fe{sub 2} series and its Ta concentration dependence discussed. An unusual behavior is revealed in the paramagnetic state of intermediate compositions, it gives rise to the rapid increase and saturation of the local spin fluctuations of the 3d electrons. This new result is analysed in the frame of the theory of Moriya. For a chosen composition Hf{sub 0.825}Ta{sub 0.175}Fe{sub 2}, exhibiting such remarkable features, a detailed investigation is carried out under hydrostatic pressure up to 1?GPa in order to investigate the volume effect on the magnetic properties. With increasing pressure, the magnetic transition temperature T{sub FM-AFM} from ferromagnetic to antiferromagnetic order decreases strongly non-linearly and disappears at a critical pressure of 0.75?GPa. In the pressure-induced AFM state, the field-induced first-order AFM-FM transition appears and the complex temperature dependence of the AFM-FM transition field is explained by the contribution from both the magnetic and elastic energies caused by the significant temperature variation of the amplitude of the local Fe magnetic moment. The application of an external pressure leads also to the progressive decrease of the Néel temperature T{sub N}. In addition, a large pressure effect on the spontaneous magnetization M{sub S} for pressures below 0.45?GPa, dln(M{sub s})/dP?=??6.3?×?10{sup ?2?}GPa{sup ?1} was discovered. The presented results are consistent with Moriya's theoretical predictions and can significantly help to better understand the underlying physics of itinerant electron magnetic systems nowadays widely investigated for both fundamental and applications purposes.

  1. From fluorite to pyrochlore: Characterisation of local and average structure of neodymium zirconate, Nd{sub 2}Zr{sub 2}O{sub 7}

    SciTech Connect (OSTI)

    Payne, Julia L.; Tucker, Matthew G.; Evans, Ivana Radosavljevi?

    2013-09-15

    The structural characterisation of Nd{sub 2}Zr{sub 2}O{sub 7} prepared via a precursor route was performed using a combination of local and average structure probes (neutron total scattering, X-ray and neutron diffraction). We present the first total scattering and reverse Monte Carlo (RMC) modelling study of Nd{sub 2}Zr{sub 2}O{sub 7}, which provides compelling evidence for the adoption of a disordered fluorite-type structure by Nd{sub 2}Zr{sub 2}O{sub 7} prepared by a low-temperature precursor route. Annealing the material at high temperatures leads to a transformation to a pyrochlore-type structure; however, Rietveld refinement using powder neutron diffraction data shows that the oxygen sublattice retains a degree of disorder. - Graphical abstract: Display Omitted - Highlights: • The first total scattering and RMC modelling study of Nd{sub 2}Zr{sub 2}O{sub 7}. • Demonstration that the synthetic route influences the crystal structure adopted. • Insight into the importance of total scattering in studies of complex superstructures, especially for nano-sized materials.

  2. PHYSICAL REVIEW B 86, 144109 (2012) Intrinsic point-defect equilibria in tetragonal ZrO2: Density functional theory analysis

    E-Print Network [OSTI]

    Yildiz, Bilge

    2012-01-01

    on the technologically important tetragonal zirconium oxide, T-ZrO2. We showed that phonon free energy and electronic) belongs to the list of the most important metal oxides due to its wide usage in different technological for Electrochemical Interfaces, Department of Nuclear Science and Engineering, Massachusetts Institute of Technology

  3. Surface Passivation of Nanoporous TiO2 via Atomic Layer Deposition of ZrO2 for Solid-State Dye-Sensitized Solar Cell Applications

    E-Print Network [OSTI]

    Surface Passivation of Nanoporous TiO2 via Atomic Layer Deposition of ZrO2 for Solid-State Dye; ReVised Manuscript ReceiVed: August 22, 2009 We report here the utilization of atomic layer deposition to passivate surface trap states in mesoporous TiO2 nanoparticles for solid-state dye

  4. Stress Relaxation of Compression Loaded Plasma-Sprayed 7 Wt% Y2O3ZrO2 Stand-Alone Coatings

    E-Print Network [OSTI]

    Trice, Rodney W.

    -temperature environments such as gas-turbine engines.1­4 TBCs typically consist of a metallic substrate coated with an B100Stress Relaxation of Compression Loaded Plasma-Sprayed 7 Wt% Y2O3­ZrO2 Stand-Alone Coatings Graeme R. Dickinson, Chris Petorak, Keith Bowman, and Rodney W. Tricew School of Materials Engineering

  5. Comment on “Correlation and relativistic effects in U metal and U-Zr alloy: Validation of ab initio approaches”

    SciTech Connect (OSTI)

    Söderlind, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Landa, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Turchi, P. E. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-10-01

    In a recent paper, Xie et al. [Phys. Rev. B 88, 235128 (2013)], report that the density-functional theory (DFT) with the so-called DFT plus Hubbard U (DFT+U) modification improves energetics, volumes, and formation enthalpies over the standard form of DFT for uranium metal and U-Zr alloys. Also, spin-orbit coupling (SOC) was argued to advance the aforementioned properties in these systems. We demonstrate, contrarily, that neither the Hubbard U approach nor SOC is necessary for a correct description of uranium metal and U-Zr alloys. We further illustrate that the combination of DFT+U and SOC in the projector augmented-wave calculations by Xie et al. results in unrealistically large volume expansions, particularly for ?-U, in stark contrast to all previous calculations for elemental uranium. This in turn may also explain why the DFT+U with SOC model predicts negative enthalpy of mixing in the U-Zr alloy system contradicting conventional DFT as well as one of the main features of the experimental U-Zr phase diagram. The assertion by Xie et al. that DFT+U is an improvement over DFT for these systems is illustrated to be incorrect.

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

    E-Print Network [OSTI]

    Bobnar, Vid

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

  7. Strong blue and white photoluminescence emission of BaZrO{sub 3} undoped and lanthanide doped phosphor for light emitting diodes application

    SciTech Connect (OSTI)

    Romero, V.H.; De la Rosa, E.; Salas, P.; Velazquez-Salazar, J.J.

    2012-12-15

    In this paper, we report the obtained strong broadband blue photoluminescence (PL) emission centered at 427 nm for undoped BaZrO{sub 3} observed after 266 nm excitation of submicron crystals prepared by hydrothermal/calcinations method. This emission is enhanced with the introduction of Tm{sup 3+} ions and is stronger than the characteristic PL blue emission of such lanthanide. The proposed mechanism of relaxation for host lattice emission is based on the presence of oxygen vacancies produced during the synthesis process and the charge compensation due to the difference in the electron valence between dopant and substituted ion in the host. Brilliant white light emission with a color coordinate of (x=0.29, y=0.32) was observed by combining the blue PL emission from the host with the green and red PL emission from Tb{sup 3+} and Eu{sup 3+} ions, respectively. The color coordinate can be tuned by changing the ratio between blue, green and red band by changing the concentration of lanthanides. - Graphical abstract: Strong blue emission from undoped BaZrO{sub 3} phosphor and white light emission by doping with Tb{sup 3+} (green) and Eu{sup 3+} (red) after 266 nm excitation. Highlights: Black-Right-Pointing-Pointer Blue emission from BaZrO{sub 3} phosphor. Black-Right-Pointing-Pointer Blue emission enhanced with Tm{sup 3+}. Black-Right-Pointing-Pointer White light from BaZrO{sup 3+} phosphor.

  8. Preparation and Characterization of Au-ZrO2-SiO2 Nanocomposite Spheres and Their Application in Enrichment and Detection of Organophosphorus Agents

    SciTech Connect (OSTI)

    Yang, Yuqi; Tu, Haiyang; Zhang, Aidong; Du, Dan; Lin, Yuehe

    2012-03-01

    Au-ZrO{sub 2}-SiO{sub 2} nanocomposite spheres were synthesized and used as selective sorbents for the solid-phase extraction (SPE) of orananophosphorous agents. A non-enzymatic electrochemical sensor based on an Au-ZrO{sub 2}-SiO{sub 2} modified electrode was developed for selective detection of orananophosphorous pesticides (OPs). The Au-ZrO{sub 2}-SiO{sub 2} nanocomposite spheres were synthesized by hydrolysis and condensation of zirconia n-butoxide (TBOZ) on the surface of SiO{sub 2} spheres and then introduction of gold nanoparticles on the surface. Transmission electron microscope and X-ray photoelectron spectroscopy were performed to characterize the formation of the nanocomposite sphere. Fast extraction of OP was achieved by Au-ZrO{sub 2}-SiO{sub 2} modified electrode within 5 min via the specific affinity between zirconia and phosphoric group. The assay yields a broad concentration range of paraoxon-ethyl from 1.0 to 500 ng/mL{sup -1} with a detection limit 0.5 ng/mL{sup -1}. This selective and sensitive method holds great promise for the enrichment and detection of OPs.

  9. Electrical and dielectric properties of ZnO and CeO{sub 2} doped ZrTi{sub 2}O{sub 6} ceramic

    SciTech Connect (OSTI)

    George, Aneesh; Thomas, Jijimon K.; John, Annamma [Department of Physics, Mar Ivanios College, Thiruvananthapuram 695015 (India); Solomon, Sam, E-mail: samdmrl@yahoo.com [Department of Physics, Mar Ivanios College, Thiruvananthapuram 695015, India and Department of Physics, St. John's College, Anchal, Kollam 691306 (India)

    2014-01-28

    Zirconium oxide (ZrO{sub 2}) and titanium dioxide (TiO{sub 2}) are the important catalyst supports, since it has acidic and basic properties. The intermediate phase zirconium titanate ZrTi{sub 2}O{sub 6}, which is a solid solution with Zr:Ti ratio 1:2 has outstanding dielectric properties. The effects of doping of ZnO and CeO{sub 2} on the dielectric and electrical properties of ZrTi{sub 2}O{sub 6} ceramic are investigated. On adding 0.5 wt% ZnO, the dielectric constant is increased but, on adding CeO{sub 2}, the dielectric constant is decreased. The bulk density of pure sample sintered at 1530 °C is 91% of theoretical density while that of the doped samples sintered at 1450 °C is more than 94% of theoretical density. Scanning electron micrographs reveal that the samples are well sintered with minimum porosity. The semicircle behavior in the Cole-Cole plots at room temperature reveals that the samples are good ionic conductor. The induced impedance is reduced for doped samples and this can be used as a material for electrolyte in Solid Oxide Fuel Cell.

  10. PHYSICAL REVIEW B 85, 155202 (2012) Structural, electronic, and hyperfine properties of pure and Ta-doped m-ZrO2

    E-Print Network [OSTI]

    Svane, Axel Torstein

    2012-01-01

    , in refractory materials, solid oxide fuel cell electrolytes, catalyst substrates, protective coatings Zirconium dioxide (zirconia) is one of the most important compounds in materials science and technology and (sometimes) with the addition of small amounts of impurities, ZrO2 has applications, for example

  11. Characterization and oxidation states of Cu and Pd in Pd?CuO/ZnO/ZrO[subscript 2] catalysts for hydrogen production by methanol partial oxidation

    SciTech Connect (OSTI)

    Schuyten, S.; Guerrero, S.; Miller, J.T.; Shibatae, T.; Wolf, E.E.

    2009-01-30

    Copper and zinc oxide based catalysts prepared by coprecipitation were promoted with palladium and ZrO{sub 2}, and their activity and selectivity for methanol oxidative reforming was measured and characterized by N{sub 2}O decomposition, X-ray absorption spectroscopy, BET, X-ray photoelectron spectroscopy, X-ray diffraction, and temperature programmed reduction. Addition of ZrO{sub 2} increased copper dispersion and surface area, with little effect on activity, while palladium promotion significantly enhanced activity with little change of the catalytic structure. A catalyst promoted with both ZrO{sub 2} and palladium yielded hydrogen below 150 C. EXAFS results under reaction conditions showed that the oxidation state of copper was influenced by palladium in the catalyst bulk. A palladium promoted catalyst contained 90% Cu{sup 0}, while the copper in an unpromoted catalyst was 100% Cu{sup 1+} at the same temperature. Palladium preferentially forms an unstable alloy with copper instead of zinc during reduction, which persists during reaction regardless of copper oxidation state. A 100-h time on stream activity measurement showed growth in copper crystallites and change in copper oxidation state resulting in decreasing activity and selectivity. A kinetic model of the reaction pathway showed that palladium and ZrO{sub 2} promoters lower the activation energy of methanol combustion and steam reforming reactions.

  12. Comparison of the vacuum-ultraviolet radiation response of HfO{sub 2}/SiO{sub 2}/Si dielectric stacks with SiO{sub 2}/Si

    SciTech Connect (OSTI)

    Upadhyaya, G. S.; Shohet, J. L.

    2007-02-12

    Vacuum ultraviolet (vuv) emitted during plasma processing degrades dielectrics by generating electron-hole pairs. VUV-induced charging of SiO{sub 2}/p-Si and HfO{sub 2}/SiO{sub 2}/p-Si dielectric stacks are compared. For SiO{sub 2}/p-Si, charging is observed for photon energies >15 eV by ionization of dielectric atoms from photoinjected electrons. In HfO{sub 2}/SiO{sub 2}/p-Si, charging is observed for photon >10 eV and is due to ionization by photoinjected electrons and by H{sup +} trapping in the HfO{sub 2}/SiO{sub 2} bulk. Hydrogen appears during annealing at the Si-SiO{sub 2} interface forming Si-H, which, during irradiation, is depassivated by photoinjected electrons. The authors conclude that dielectric charging in thin oxides (<10 nm) occurs more easily in HfO{sub 2}/SiO{sub 2} than in SiO{sub 2}.

  13. In-operando hard X-ray photoelectron spectroscopy study on the impact of current compliance and switching cycles on oxygen and carbon defects in resistive switching Ti/HfO{sub 2}/TiN cells

    SciTech Connect (OSTI)

    Sowinska, Malgorzata Bertaud, Thomas; Walczyk, Damian; Calka, Pauline; Walczyk, Christian; Thiess, Sebastian; Alff, Lambert; Schroeder, Thomas

    2014-05-28

    In this study, direct experimental materials science evidence of the important theoretical prediction for resistive random access memory (RRAM) technologies that a critical amount of oxygen vacancies is needed to establish stable resistive switching in metal-oxide-metal samples is presented. In detail, a novel in-operando hard X-ray photoelectron spectroscopy technique is applied to non-destructively investigates the influence of the current compliance and direct current voltage sweep cycles on the Ti/HfO{sub 2} interface chemistry and physics of resistive switching Ti/HfO{sub 2}/TiN cells. These studies indeed confirm that current compliance is a critical parameter to control the amount of oxygen vacancies in the conducting filaments in the oxide layer during the RRAM cell operation to achieve stable switching. Furthermore, clear carbon segregation towards the Ti/HfO{sub 2} interface under electrical stress is visible. Since carbon impurities impact the oxygen vacancy defect population under resistive switching, this dynamic carbon segregation to the Ti/HfO{sub 2} interface is suspected to negatively influence RRAM device endurance. Therefore, these results indicate that the RRAM materials engineering needs to include all impurities in the dielectric layer in order to achieve reliable device performance.

  14. Surface and interfacial reaction study of half cycle atomic layer deposited HfO{sub 2} on chemically treated GaSb surfaces

    SciTech Connect (OSTI)

    Zhernokletov, D. M. [Department of Physics, University of Texas at Dallas, Richardson, Texas 75080 (United States)] [Department of Physics, University of Texas at Dallas, Richardson, Texas 75080 (United States); Dong, H.; Brennan, B.; Kim, J. [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080 (United States)] [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080 (United States); Yakimov, M.; Tokranov, V.; Oktyabrsky, S. [College of Nanoscale Science and Engineering, University at Albany - SUNY, Albany, New York 12203 (United States)] [College of Nanoscale Science and Engineering, University at Albany - SUNY, Albany, New York 12203 (United States); Wallace, R. M. [Department of Physics, University of Texas at Dallas, Richardson, Texas 75080 (United States) [Department of Physics, University of Texas at Dallas, Richardson, Texas 75080 (United States); Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080 (United States)

    2013-04-01

    An in situ half-cycle atomic layer deposition/X-ray photoelectron spectroscopy (XPS) study was conducted in order to investigate the evolution of the HfO{sub 2} dielectric interface with GaSb(100) surfaces after sulfur passivation and HCl etching, designed to remove the native oxides. With the first pulses of tetrakis(dimethylamido)hafnium(IV) and water, a decrease in the concentration of antimony oxide states present on the HCl-etched surface is observed, while antimony sulfur states diminished below the XPS detection limit on sulfur passivated surface. An increase in the amount of gallium oxide/sulfide is seen, suggesting oxygen or sulfur transfers from antimony to gallium during antimony oxides/sulfides decomposition.

  15. Visible-light-driven photocatalytic performance of nitrogen-doped Ti{sub 1?x}Zr{sub x}O{sub 2} solid solution

    SciTech Connect (OSTI)

    Gao, Bifen, E-mail: bfgao@hqu.edu.cn [Department of Applied Chemistry, College of Materials Science and Engineering, Huaqiao University, Xiamen 361021 (China)] [Department of Applied Chemistry, College of Materials Science and Engineering, Huaqiao University, Xiamen 361021 (China); Luo, Xiuzhen [Zhangzhou Health Vocational College, Zhangzhou 363000 (China)] [Zhangzhou Health Vocational College, Zhangzhou 363000 (China); Fu, Hao; Lin, Bizhou; Chen, Yilin [Department of Applied Chemistry, College of Materials Science and Engineering, Huaqiao University, Xiamen 361021 (China)] [Department of Applied Chemistry, College of Materials Science and Engineering, Huaqiao University, Xiamen 361021 (China); Gu, Zhanjun [Laboratory for Bio-Environmental Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)] [Laboratory for Bio-Environmental Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2013-02-15

    Graphical abstract: Display Omitted Highlights: ? Dual modifications on the energy band of TiO{sub 2} are achieved by N and Zr co-doping. ? Nitrogen and zirconium dopants have different doping positions in the catalyst. ? A synergic impact of nitrogen and zirconium on photocatalytic activity is observed. ? A mechanism for the high performance of nitrogen-doped Ti{sub 1?x}Zr{sub x}O{sub 2} solid solution is proposed. -- Abstract: Nitrogen-doped Ti{sub 1?x}Zr{sub x}O{sub 2} solid solutions have been synthesized by a multi-step sol–gel process followed by hydrothermal treatment in ammonia solution. XRD, XPS and UV–vis diffuse reflectance analyses indicated that nitrogen was doped in the surface layer of catalyst, introducing surface states located close to valence band. However, Zr{sup 4+} was successfully incorporated into the bulk lattice of TiO{sub 2} so as to induce the up-shift of conduction band. Compared to pristine TiO{sub 2} and nitrogen-doped TiO{sub 2}, nitrogen-doped Ti{sub 1?x}Zr{sub x}O{sub 2} exhibited much higher efficiency for the degradation of Acid Red 88 solution and gaseous benzene under visible light irradiation, attributed to the synergetic effect of nitrogen and zirconium on the energy band. Specifically, the presence of surface states in the band gap enabled the extended visible light response and the up-shift of conduction band facilitated the excited electron interfacial transfer and hence suppressed efficiently the recombination of charge carriers.

  16. Alternation of the Pd Lattice in Nano-Sized-Pd/ZrO2 Composite during Hydrogen Absorption

    SciTech Connect (OSTI)

    Arachi, Yoshinori; Asai, Takeshi; Emura, Shuichi; Omura, Akira; Nunogaki, Masanobu; Yamaura, Shunichi; Inoue, Akihisa; Arata, Yoshiaki

    2007-02-02

    Structural analysis of high Deuterium absorbed 5 nm Pd particles in dispersed ZrO2 has been carried out using XAFS techniques. X-ray absorption spectra around the Pd K-absorption edge were observed and analyzed. The Pd-Pd bonding distance in the fcc Pd lattice was enlarged by 0.08 {approx} 0.09 A during absorption of deuterium, and it completely reverted to its original state with the release of deuterium while maintaining the crystal lattice symmetry. These changes provide evidence that deuterium locates not on the surface of the Pd particle, but rather within the Pd crystal lattice. XANES spectra clearly indicate that any change in the oxidation state of Pd are not observed, resulting in no reaction of the absorbed Deuterium atoms with Pd atoms. This paper reports the alternation of Pd lattice in nano-sized composite during hydrogen absorption. The possible models of deuterium position in the Pd lattice are also discussed.

  17. Tsovaltzi, D., Weinberger, A., Scheuer, O., Dragon, T. & McLaren, B.M., (2012). Argument diagrams in Facebook: Facilitating the formation of scientifically sound opinions. In: A. Ra-

    E-Print Network [OSTI]

    McLaren, Bruce Martin

    2012-01-01

    in Facebook: Facilitating the formation of scientifically sound opinions. In: A. Ra- venscroft, S. Lindstaedt in Facebook: Facilitating the Formation of Scientifically Sound Opinions Dimitra Tsovaltzi, Armin Weinberger Dimitra.tsovalzi@mx.uni-saarland.de Students use Facebook to organize their classroom experiences [1

  18. A first-principles density functional theory study of the electronic structural and thermodynamic properties of M2ZrO3 and M2CO3 (M=Na, K) and their capabilities for CO2 capture

    SciTech Connect (OSTI)

    Yuhua Duan

    2012-01-01

    Alkali metal zirconates could be used as solid sorbents for CO{sub 2} capture. The structural, electronic, and phonon properties of Na{sub 2}ZrO{sub 3}, K{sub 2}ZrO{sub 3}, Na{sub 2}CO{sub 3}, and K{sub 2}CO{sub 3} are investigated by combining the density functional theory with lattice phonon dynamics. The thermodynamics of CO{sub 2} absorption/desorption reactions of these two zirconates are analyzed. The calculated results show that their optimized structures are in a good agreement with experimental measurements. The calculated band gaps are 4.339 eV (indirect), 3.641 eV (direct), 3.935 eV (indirect), and 3.697 eV (direct) for Na{sub 2}ZrO{sub 3}, K{sub 2}ZrO{sub 3}, Na{sub 2}CO{sub 3}, and K{sub 2}CO{sub 3}, respectively.The calculated phonon dispersions and phonon density of states for M{sub 2}ZrO{sub 3} and M{sub 2}CO{sub 3} (M = K, Na, Li) revealed that from K to Na to Li, their frequency peaks are shifted to high frequencies due to the molecular weight decreased from K to Li. From the calculated reaction heats and relationships of free energy change versus temperatures and CO{sub 2} pressures of the M{sub 2}ZrO{sub 3} (M = K, Na, Li) reacting with CO{sub 2}, we found that the performance of Na{sub 2}ZrO{sub 3} capturing CO{sub 2} is similar to that of Li{sub 2}ZrO{sub 3} and is better than that of K{sub 2}ZrO{sub 3}. Therefore, Na{sub 2}ZrO{sub 3} and Li{sub 2}ZrO{sub 3} are good candidates of high temperature CO{sub 2} sorbents and could be used for post combustion CO{sub 2} capture technologies.

  19. Bio-corrosion and cytotoxicity studies on novel Zr55Co30Ti15 and Cu60Zr20Ti20 metallic glasses

    SciTech Connect (OSTI)

    Vincent, S.; Daiwile, A.; Devi, S. S.; Kramer, M. J.; Besser, M. F.; Murty, B. S.; Bhatt, Jatin

    2014-09-26

    Metallic glasses are a potential and compatible implant candidate for biomedical applications. In the present investigation, a comparative study between novel Zr55Co30Ti15 and Cu60Zr20Ti20 metallic glasses is carried out to evaluate in vitro biocompatibility using simulated body fluids. The bio-corrosion behavior of Zr- and Cu-based metallic glasses in different types of artificial body fluids such as artificial saliva solution, phosphate-buffered saline solution, artificial blood plasma solution, and Hank’s balanced saline solution is evaluated using potentiodynamic polarization studies at a constant body temperature of 310.15 K (37 °C). Surface morphology of samples after bio-corrosion experiments was observed by scanning electron microscopy. In vitro cytotoxicity test on glassy alloys were performed using human osteosarcoma cell line as per 10993-5 guidelines from International Organization for Standardization. As a result, the comparative study between Zr- and Cu-based glassy alloys provides vital information about the effect of elemental composition on biocompatibility of metallic glasses.

  20. Porosity and biocompatibility study of ceramic implants based on ZrO{sub 2} and Al{sub 2}O{sub 3}

    SciTech Connect (OSTI)

    Litvinova, Larisa E-mail: vshupletsova@mail.ru Shupletsova, Valeria E-mail: vshupletsova@mail.ru Leitsin, Vladimir E-mail: vshupletsova@mail.ru; Vasyliev, Roman E-mail: zoubov77@yahoo.com; Zubov, Dmitry E-mail: zoubov77@yahoo.com; Buyakov, Ales E-mail: kulkov@ms.tsc.ru; Kulkov, Sergey E-mail: kulkov@ms.tsc.ru

    2014-11-14

    The work studies ZrO{sub 2}(Me{sub x}O{sub y})-based porous ceramics produced from the powders consisting of hollow spherical particles. It was shown that the structure is represented by a cellular framework with bimodal porosity consisting of sphere-like large pores and pores that were not filled with the powder particles during the compaction. For such ceramics, the increase of pore volume is accompanied by the increased strain in an elastic area. It was also shown that the porous ZrO{sub 2} ceramics had no acute or chronic cytotoxicity. At the same time, ceramics possess the following osteoconductive properties: adhesion support, spreading, proliferation and osteogenic differentiation of MSCs.

  1. In situ observation of defect annihilation in Kr ion-irradiated bulk Fe/amorphous-Fe 2 Zr nanocomposite alloy

    SciTech Connect (OSTI)

    Yu, K. Y.; Fan, Z.; Chen, Y.; Song, M.; Liu, Y.; Wang, H.; Kirk, M. A.; Li, M.; Zhang, X.

    2014-08-26

    Enhanced irradiation tolerance in crystalline multilayers has received significant attention lately. However, little is known on the irradiation response of crystal/amorphous nanolayers. We report on in situ Kr ion irradiation studies of a bulk Fe96Zr4 nanocomposite alloy. Irradiation resulted in amorphization of Fe2Zr and formed crystal/amorphous nanolayers. ?-Fe layers exhibited drastically lower defect density and size than those in large ?-Fe grains. In situ video revealed that mobile dislocation loops in ?-Fe layers were confined by the crystal/amorphous interfaces and kept migrating to annihilate other defects. This study provides new insights on the design of irradiation-tolerant crystal/amorphous nanocomposites.

  2. Research Update: Reactively sputtered nanometer-thin ZrN film as a diffusion barrier between Al and boron layers for radiation detector applications

    SciTech Connect (OSTI)

    Golshani, Negin, E-mail: negingolshani@gmail.com; Mohammadi, V.; Schellevis, H.; Beenakker, C. I. M.; Ishihara, R. [ECTM, DIMES, Faculty of Electrical Engineering (EWI), Delft University of Technology (TU Delft), Feldmannweg 17, P.O. Box 5053, 2628 CT Delft (Netherlands)

    2014-10-01

    In this paper, optimization of the process flow for PureB detectors is investigated. Diffusion barrier layers between a boron layer and the aluminum interconnect can be used to enhance the performance and visual appearance of radiation detectors. Few nanometers-thin Zirconium Nitride (ZrN) layer deposited by reactive sputtering in a mixture of Ar/N{sub 2}, is identified as a reliable diffusion barrier with better fabrication process compatibility than others. The barrier properties of this layer have been tested for different boron layers deposited at low and high temperatures with extensive optical microscopy analyses, electron beam induced current, SEM, and electrical measurements. This study demonstrated that spiking behavior of pure Al on Si can be prevented by the thin ZrN layer thus improving the performance of the radiation detectors fabricated using boron layer.

  3. Syngas production from butane using a flame-made Rh/Ce0.5Zr0.5O2 Nico Hotz a

    E-Print Network [OSTI]

    Daraio, Chiara

    Syngas production from butane using a flame-made Rh/Ce0.5Zr0.5O2 catalyst Nico Hotz a , Michael J the production of H2- and CO-rich syngas from butane was investigated for different Rh loadings (0­2.0 wt% Rh for a temperature range from 225 to 750 8C. The main goal of this study was the efficient processing of butane

  4. Influence of crystalline phase and defects in the ZrO{sub 2} nanoparticles synthesized by thermal plasma route on its photocatalytic properties

    SciTech Connect (OSTI)

    Nawale, Ashok B.; Kanhe, Nilesh S.; Bhoraskar, S.V.; Mathe, V.L.; Das, A.K.

    2012-11-15

    Graphical abstract: Thermal plasma synthesized nanophase zirconia showing the blue shift in the band gap of monoclinic phase as found from the photoabsorption spectroscopy was found to be the dominant parameter for the enhancement in its photocatalytic activity. The existence of different defect states and their concentration in as synthesized samples also inferred from the photoabsorption measurements were also found to be responsible for the enhanced photocatalytic activity of the samples. Highlights: ? Phase controlled structural formation of nanophase ZrO{sub 2} by thermal plasma route. ? Enhanced photocatalytic degradation rate of methylene blue dye. ? The blue shift in the band gap of monoclinic phase of nanocrystalline ZrO{sub 2}. ? Existence of different defect states in the as synthesized nano phase ZrO{sub 2}. ? Several competing processes which controls the photocatalytic degradation rate. -- Abstract: The photocatalytic activity of pure ZrO{sub 2} samples, prepared by a thermal plasma route, and characterized by X-ray diffraction technique was tested for the degradation of methylene blue, which is known to be a hazardous dye. Although, all these samples synthesized at different operating pressures of the thermal plasma reactor showed the photocatalytic activity; the sample synthesized at 1.33 bar of operating pressure showed the highest photocatalytic activity. The blue shift in the band gap of monoclinic phase, as observed from the photo-absorption spectroscopy, may be attributed to the enhanced photocatalytic activity. The existence of different defect states and their concentration as, inferred from the photo-absorption measurements were also found to be responsible for the enhanced photocatalytic activity of the as synthesized samples.

  5. Influence of alloying elements on grain-growth in Zr(Fe) and Cu(Fe) thin-films under in situ ion-irradiation

    E-Print Network [OSTI]

    Motta, Arthur T.

    Influence of alloying elements on grain-growth in Zr(Fe) and Cu(Fe) thin-films under in situ ion-irradiation(Fe) and Cu(Fe) were ion-irradiated in situ in a transmission electron microscope to study the influence of mixing and Cu­Fe a positive heat of mixing. Irradiations conducted at temperatures of 20­573 K showed

  6. Phonon anomalies in Pb1-xLax,,Zr0.9Ti0.1...O3 ceramics E. Buixaderas,1,a

    E-Print Network [OSTI]

    KuÂ?el, Petr

    Phonon anomalies in Pb1-xLax,,Zr0.9Ti0.1...O3 ceramics E. Buixaderas,1,a I. Gregora,1 S. Kamba,1 P modified lead zirconate titanate ceramics Pb1-xLax ZryTi1-y O3 PLZT X/Y /1-Y, where X=100x, Y =100y have The local symmetry, however, seems to be monoclinic.7 Raman scattering of PZT 90/10 ceramics8 and single

  7. Structure-activity relationship of Au-ZrO2 catalyst on formation of hydroxyl groups and its influence on CO oxidation

    SciTech Connect (OSTI)

    Karwacki, Christopher J; Ganesh, Panchapakesan; Kent, P. R. C.; Gordon, Wesley O; Peterson, Gregory W; Niu, Jun Jie; Gogotsi, Yury G.

    2013-01-01

    The effect of changes in morphology and surface hydroxyl species upon thermal treatment of zirconia on the oxidation activity of Au/ZrO2 catalyst was studied. We observed using transmission Fourier transform infrared (FTIR) spectroscopy progressive changes in the presence of monodentate (type I), bidentate (type II) and hydrogen bridged species (type III) for each of the thermally treated (85 to 500 C) supports consisting of bare zirconia and Au/ZrO2 catalysts. Furthermore, structural changes in zirconia were accompanied by an increase in crystal size (7 to 58 nm) and contraction of the supports porosity (SSA 532 to 7 m2 g 1) with increasing thermal treatment. Deposition of gold nanoparticles under similar preparation conditions on different thermally treated zirconia resulted in changes in the mean gold cluster size, ranging from 3.7 to 5.6 nm. Changes in the surface hydroxyl species, support structure and size of the gold centers are important parameters responsible for the observed decrease (>90%) in CO conversion activity for the Au/ZrO2 catalysts. Density functional theory calculations provide evidence of increased CO binding to Au nanoclusters in the presence of surface hydroxyls on zirconia, which increases charge transfer at the perimeter of the gold nanocluster on zirconia support. This further helps in reducing a model CO-oxidation reaction barrier in the presence of surface hydroxyls. This work demonstrates the need to understand the structure activity relationship of both the support and active particles for the design of catalytic materials.

  8. Structure-Activity Relationship of Au/ZrO2 Catalyst on Formation of Hydroxyl Groups and Its Influence on CO Oxidation

    SciTech Connect (OSTI)

    Karwacki, Christopher J; Ganesh, Panchapakesan; Gordon, Wesley O; Peterson, Gregory W; Niu, Jun Jie; Gogotsi, Yury G.

    2013-01-01

    The effect of changes in morphology and surface hydroxyl species upon thermal treatment of zirconia on the oxidation activity of Au/ZrO2 catalyst was studied. We observed using transmission fourier transform infrared (FTIR) spectroscopy progressive changes in the presence of monodentate (type I), bidentate (type II) and hydrogen bridged species (type III) for each of the thermally treated (85 to 500 C) supports consisting of bare zirconia and Au/ZrO2 catalysts. Furthermore, structural changes in zirconia were accompanied by an increase in crystal size (7 to 58 nm) and contraction of the supports porosity (SSA 532 to 7 m2/g) with increasing thermal treatment. Deposition of gold nanoparticles under similar preparation conditions on different thermally treated zirconia resulted in changes in the mean gold cluster size, ranging from 3.7 to 5.6 nm. Changes in the surface hydroxyl species, support structure and size of the gold centers are important parameters responsible for the observed decrease (> 90 %) in CO conversion activity for the Au/ZrO2 catalysts. Density functional theory calculations provide evidence of increased CO binding to Au nanoclusters in the presence of surface hydroxyls on zirconia, which increases charge transfer at the perimeter of the gold nanocluster on zirconia support. This further helps in reducing a model CO-oxidation reaction barrier in the presence of surface hydroxyls. This work demonstrates the need to understand the structure-activity relationship of both the support and active particles for the design of catalytic materials.

  9. Influence of post-deposition annealing on interfacial properties between GaN and ZrO{sub 2} grown by atomic layer deposition

    SciTech Connect (OSTI)

    Ye, Gang; Wang, Hong, E-mail: ewanghong@ntu.edu.sg; Arulkumaran, Subramaniam; Ng, Geok Ing; Li, Yang; Ang, Kian Siong [Novitas, Nanoelectronics Center of Excellence, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Geok Ng, Serene Lay; Ji, Rong [Data Storage Institute, Agency for Science Technology and Research (A-STAR), 5 Engineering Drive 1, 117608 (Singapore); Liu, Zhi Hong [Singapore-MIT Alliance for Research and Technology, 1 CREATE Way, Singapore 138602 (Singapore)

    2014-10-13

    Influence of post-deposition annealing on interfacial properties related to the formation/annihilation of interfacial GaO{sub x} layer of ZrO{sub 2} grown by atomic layer deposition (ALD) on GaN is studied. ZrO{sub 2} films were annealed in N{sub 2} atmospheres in temperature range of 300?°C to 700?°C and analyzed by X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy. It has been found that Ga-O bond to Ga-N bond area ratio decreases in the samples annealed at temperatures lower than 500?°C, which could be attributed to the thinning of GaO{sub x} layer associated with low surface defect states due to “clean up” effect of ALD-ZrO{sub 2} on GaN. However, further increase in annealing temperature results in deterioration of interface quality, which is evidenced by increase in Ga-O bond to Ga-N bond area ratio and the reduction of Ga-N binding energy.

  10. Full-length U-xPu-10Zr (x=0, 8, 19 wt%) Fast Reactor Fuel Test in FFTF

    SciTech Connect (OSTI)

    D. L. Porter; H.C. Tsai

    2012-08-01

    The Integral Fast Reactor-1 (IFR-1) experiment performed in the Fast Flux Test Facility (FFTF) was the only U-Pu-10Zr (Pu-0, 8 and 19 wt%) metallic fast reactor test with commercial-length (91.4 cm active fuel column length) conducted to date. With few remaining test reactors there is little opportunity for performing another test with a long active fuel column. The assembly was irradiated to the goal burnup of 10 at.%. The beginning of life (BOL) peak cladding temperature of the hottest pin was 608?C, cooling to 522?C at end of life (EOL). Selected fuel pins were examined non destructively using neutron radiography, precision axial gamma scanning, and both laser and spiral contact cladding profilometry. Destructive exams included plenum gas pressure, volume, and gas composition determinations on a number of pins followed by optical metallography, electron probe microanalysis (EPMA), and alpha and beta gamma autoradiography on a single U-19Pu-10Zr pin. The post-irradiation examinations (PIEs) showed very few differences compared to the short-pin (34.3 cm fuel column) testing performed on fuels of similar composition in Experimental Breeder Reactor-II (EBR-II). The fuel column grew axially slightly less than observed in the short pins, but with the same pattern of decreasing growth with increasing Pu content. There was a difference in the fuel-cladding chemical interaction (FCCI) in that the maximum cladding penetration by interdiffusion with fuel/fission products did not occur at the top of the fuel column where the cladding temperature is highest, as observed in EBR-II tests. Instead, the more exaggerated fission-rate profile of the FFTF pins resulted in a peak FCCI at ~0.7 X/L axial location along the fuel column. This resulted from a lower production of rare earth fission products higher in the fuel column as well as a much smaller delta-T between fuel center and cladding, and therefore less FCCI, despite the higher cladding temperature. This behavior could actually help extend the life of a fuel pin in a “long pin” reactor design to a higher peak fuel burnup.

  11. Crystal structure and antiferromagnetic ordering of quasi-2D [Cu(HF{sub 2})(pyz){sub 2}]TaF{sub 6} (pyz = pyrazine).

    SciTech Connect (OSTI)

    Manson, J. L.; Schlueter, J. A.; McDonald, R. D.; Singleton, J.; Materials Science Division; Eastern Washington Univ.; LANL

    2010-04-01

    The crystal structure of the title compound was determined by X-ray diffraction at 90 and 295 K. Copper(II) ions are coordinated to four bridging pyz ligands to form square layers in the ab-plane. Bridging HF{sub 2}{sup -} ligands join the layers together along the c-axis to afford a tetragonal, three-dimensional (3D) framework that contains Taf{sub 6}{sup -} anions in every cavity. At 295 K, the pyz rings lie exactly perpendicular to the layers and cooling to 90 K induces a canting of those rings. Magnetically, the compound exhibits 2D antiferromagnetic correlations within the 2D layers with an exchange interaction of -13.1(1) K. Weak interlayer interactions, as mediated by Cu-F-H-F-Cu, leads to long-range magnetic order below 4.2 K. Pulsed-field magnetization data at 0.5 K show a concave curvature with increasing B and reveal a saturation magnetization at 35.4 T.

  12. Study on the Ge{sub 1?x}Sn{sub x}/HfO{sub 2} interface and its impacts on Ge{sub 1?x}Sn{sub x} tunneling transistor

    SciTech Connect (OSTI)

    Qiu, Yingxin; Wang, Runsheng, E-mail: ruhuang@pku.edu.cn, E-mail: r.wang@pku.edu.cn; Huang, Qianqian; Huang, Ru, E-mail: ruhuang@pku.edu.cn, E-mail: r.wang@pku.edu.cn [Key Laboratory of Microelectronic Devices and Circuits, Institute of Microelectronics, Peking University, Beijing 100871 (China)

    2014-06-21

    In this paper, we employ first-principle calculation to investigate the Ge{sub 1?x}Sn{sub x}/HfO{sub 2} interface, and then evaluate its impacts on Ge{sub 1?x}Sn{sub x} tunneling field-effect transistor (TFET). First-principle calculations of Ge{sub 1?x}Sn{sub x}/HfO{sub 2} interfaces in the oxygen-rich process atmosphere indicate that the interface states originate from the Ge and Sn dangling bond, rather than Hf-bond. The total density of state shows that there are more interface states in the semiconductor bandgap with increasing Sn fraction. By further incorporating the material and interface parameters from density functional theory calculation into advanced device simulation, the electrical characteristics of Ge{sub 1?x}Sn{sub x} TFET are investigated. Removing the Sn atom from the first atom layer of Ge{sub 1?x}Sn{sub x} in device processes is found to be beneficial to reduce the degradations. For the degradation mechanisms, the trap-assisted-tunneling is the dominant mechanism at the low Sn fraction, and enhanced Shockley-Read-Hall recombination induced by traps becomes the dominant mechanism with increasing Sn fraction. The results are helpful for the interface optimization of Ge{sub 1?x}Sn{sub x} TFET.

  13. Effect of current compliance and voltage sweep rate on the resistive switching of HfO{sub 2}/ITO/Invar structure as measured by conductive atomic force microscopy

    SciTech Connect (OSTI)

    Wu, You-Lin Liao, Chun-Wei; Ling, Jing-Jenn

    2014-06-16

    The electrical characterization of HfO{sub 2}/ITO/Invar resistive switching memory structure was studied using conductive atomic force microscopy (AFM) with a semiconductor parameter analyzer, Agilent 4156C. The metal alloy Invar was used as the metal substrate to ensure good ohmic contact with the substrate holder of the AFM. A conductive Pt/Ir AFM tip was placed in direct contact with the HfO{sub 2} surface, such that it acted as the top electrode. Nanoscale current-voltage (I-V) characteristics of the HfO{sub 2}/ITO/Invar structure were measured by applying a ramp voltage through the conductive AFM tip at various current compliances and ramp voltage sweep rates. It was found that the resistance of the low resistance state (RLRS) decreased with increasing current compliance value, but resistance of high resistance state (RHRS) barely changed. However, both the RHRS and RLRS decreased as the voltage sweep rate increased. The reasons for this dependency on current compliance and voltage sweep rate are discussed.

  14. Density functional theory simulations of amorphous high-oxides on a compound semiconductor alloy: a-Al2O3/InGaAs(100)-(42), a-HfO2/InGaAs(100)-(42), and a-

    E-Print Network [OSTI]

    Kummel, Andrew C.

    atomic layer deposition Appl. Phys. Lett. 104, 042904 (2014); 10.1063/1.4863440 Si passivation effects x 0.53 ) and atomic-layer deposited Al 2 O 3 and HfO 2 Appl. Phys. Lett. 94, 202110 (2009); 10.1063/1.3137187 Energy-band parameters of atomic layer deposited Al 2 O 3 and HfO 2 on In x Ga 1 - x As Appl. Phys. Lett

  15. 4500. Nasch, P.M., M.H. Manghnani, and R.A. Secco, 1997, Anomalous behavior of sound velocity and attenuation in liquid Fe-Ni-S, Science, 277, 219-221.

    E-Print Network [OSTI]

    4500. Nasch, P.M., M.H. Manghnani, and R.A. Secco, 1997, Anomalous behavior of sound velocityForschungsZentrum, Potsdam, Germany, 6-16. 4502. Blewett, D.T., P.G. Lucey, and B.R. Hawke, 1997, Clementine images., 132, 119-132. 4504. Yu, Z.-P., P.-S. Chu, and T. Schroeder, 1997, Predictive skills of seasonal

  16. it is seen that there is an enhancement in the bandwidths of f1 over f2 and RA. The bandwidth of f1 is found to be increased by 4.2

    E-Print Network [OSTI]

    Masoudi, Husain M.

    it is seen that there is an enhancement in the bandwidths of f1 over f2 and RA. The bandwidth of f1 of the bandwidth is due to stacking configuration. A measured VSWR for f1 is 1.602 and f2 is 1.585 is obtained. The input impedance measured for f1 is 45.65 j22.68 and for f2 it is 33.45 j9.239. Typical coplanar patterns

  17. The Department of Energy's Energy Efficiency and Conservation Block Grant Program Funded under the American Recovery and Reinvestment Act for the State of Pennsylvania, OAS-RA-L-11-11

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankADVANCEDInstallers/ContractorsPhotovoltaicsState of Pennsylvania OAS-RA-L-11-11 September 2011 Department

  18. Soft and hybrid-doped Pb(Zr,Ti)O{sub 3} ceramics under stress, electric field, and temperature loading

    SciTech Connect (OSTI)

    Suchanicz, J.; Kim-Ngan, N.-T.; Konieczny, K.; Jankowska-Sumara, I. [Institute of Physics, Pedagogical University, ul. Podchorazych 2, 30-084 Krakow (Poland); Balogh, A. G. [Institute of Materials Science, Technische Universitaet Darmstadt, Petersenstrasse 23, 64287 Darmstadt (Germany)

    2011-05-15

    We investigated the influence of uniaxial pressure (0-1000 bars) applied parallelly or perpendicularly to the ac or dc electric field (in a one-dimensional or two-dimensional manner) on dielectric and ferroelectric properties of selected soft and hybrid-doped PZT ceramics (1 mol. % Gd, 1 mol. % La and 1 mol. % (La+Fe)-doped Pb(Zr{sub 0.54}Ti{sub 0.46}) O{sub 3}). Applying uniaxial pressure leads to a reduction of the peak intensity of the electric permittivity ({epsilon}), of the frequency dispersion, and of the dielectric hysteresis. The peak intensity of {epsilon} becomes diffused and shifts to a higher temperatures with increasing pressure. Simultaneous application of uniaxial pressure and dc electric field (perpendicular to each other) in the poling process implies in improvement of the ferroelectric properties, indicating a new possibility for poling materials with a high coercive field and/or high electric conductivity. It was also found that simultaneous application of uniaxial pressure and dc electric field (perpendicular to each other) allowed observation of the space charge in the depolarization process. The electrostrictive coefficient Q{sub 11} and differential permittivity were evaluated from obtained data. Our results show that applying uniaxial pressure induces similar effects as increasing the Ti-ion concentration in the PZT system. We interpreted our results based on the Cochran soft-mode and domain switching processes under the action of pressure.

  19. Oxygen partial pressure influenced structural and optical properties of DC magnetron sputtered ZrO{sub 2} films

    SciTech Connect (OSTI)

    Kondaiah, P.; Madhavi, V.; Uthanna, S. [Department of Physics, Sri Venkateswara University, Tirupati-517502 (India)

    2013-02-05

    Thin films of zirconium oxide (ZrO{sub 2}) were deposited on (100) p-silicon and quartz substrates by sputtering of metallic zirconium target under different oxygen partial pressures in the range 8 Multiplication-Sign 10{sup -3}-6 Multiplication-Sign 10{sup -2}Pa. The effect of oxygen partial pressure on the structural and optical properties of the deposited films was systematically investigated. The deposition rate of the films decreased from 3.3 to 1.83 nm/min with the increase of oxygen partial pressure from 8 Multiplication-Sign 10{sup -3}-6 Multiplication-Sign 10{sup -2}Pa respectively. The X-ray diffraction profiles revealed that the films exhibit (111) refection of zirconium oxide in monoclinic phase. The optical band gap of the films increased from 5.62 to 5.80 eV and refractive index increased from 2.01 to 2.08 with the increase of oxygen partial pressure from 8 Multiplication-Sign 10{sup -3}-6 Multiplication-Sign 10{sup -2}Pa respectively.

  20. Casting evaluation of U-Zr alloy system fuel slug for SFR prepared by injection casting method

    SciTech Connect (OSTI)

    Song, Hoon; Kim, Jong-Hwan; Kim, Ki-Hwan; Lee, Chan-Bock

    2013-07-01

    Metal fuel slugs of U-Pu-Zr alloys for Sodium-cooled Fast Reactor (SFR) have conventionally been fabricated by a vacuum injection casting method. Recently, management of minor actinides (MA) became an important issue because direct disposal of the long-lived MA can be a long-term burden for a tentative repository up to several hundreds of thousand years. In order to recycle transuranic elements (TRU) retained in spent nuclear fuel, remote fabrication capability in a shielded hot cell should be prepared. Moreover, generation of long-lived radioactive wastes and loss of volatile species should be minimized during the recycled fuel fabrication step. In order to prevent the evaporation of volatile elements such as Am, alternative fabrication methods of metal fuel slugs have been studied applying gravity casting, and improved injection casting in KAERI, including melting under inert atmosphere. And then, metal fuel slugs were examined with casting soundness, density, chemical analysis, particle size distribution and microstructural characteristics. Based on these results there is a high level of confidence that Am losses will also be effectively controlled by application of a modest amount of overpressure. A surrogate fuel slug was generally soundly cast by improved injection casting method, melted fuel material under inert atmosphere.

  1. A new structural subclass of constrained geometry catalysts for the polymerization of olefins 

    E-Print Network [OSTI]

    Irwin, Levi Jacob

    2006-04-12

    in solidstate anomalies for both systems. The ansa-metallocenes Me2C(n5-C5H4) (n5-C29H36)MCl2, M = Zr, Hf and Me2C(n5-C5H4)(n5-C29H36)ZrBn2 demonstrate crystal motifs expected for ansametallocenes while Me2C(n5-C5H4)(n5-C29H36)MMe2, M=Zr, Hf exhibit diffuse...

  2. In-situ P/M Al/(ZrB{sub 2} + Al{sub 2}O{sub 3}) MMCs: Processing, microstructure and mechanical characterization[Powder Metallurgy, Metal Matrix Composites

    SciTech Connect (OSTI)

    Feng, C.F.; Froyen, L.

    1999-12-10

    In-situ metal matrix composites (MMCs) offer significant advantages over conventional MMCs from both a technical and an economic standpoint. In this paper, an in-situ MMC, i.e., Al/(10 vol.% Zr2B + 9.2 vol.% Al{sub 2}O{sub 3}), is produced starting from Al + ZrO{sub 2} + B by reactive sintering and subsequently densified by hot-pressing. The formation mechanism of ZrB{sub 2} and Al{sub 2}O{sub 3} in Al matrix is studied by XRD, thermal analysis and microstructural characterization. Reaction kinetics are also investigated based on the results of the reaction mechanism. The properties are evaluated in terms of microstructural characterization, Young's modulus and bending tests. The in-situ processing involves four intermediate steps and the transitional phases are AlB{sub 2}, Zr(O, B){sub 2} and (Zr, Al)(B, O){sub 2}. Regarding the reaction kinetics, conversion fraction vs time relationships have been established for the last three intermediate steps.

  3. WUSM RA Forum September 2007

    E-Print Network [OSTI]

    Kroll, Kristen L.

    by the University of Illinois at Chicago. http://grants.nih.gov/grants/guide/notice-files/NOT-OD-07-076.html #12;4 G&C justification, G&C will handle proposal similar to a NIH/Modular proposal as a default. Personnel costs should the Percentage of Unobligated Balance Scenario: Year 1 Year 2 NoA (approved budget) $382,500 $382,500 Previous

  4. Salishan-RA-AMTRTS.pptx

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust, High-Throughput Analysis of Protein1-0845*RV6STATDecember29/2011 Page13RLC/RBB Salishan

  5. X-ray microstructural analysis of nanocrystalline TiZrN thin films by diffraction pattern modeling

    SciTech Connect (OSTI)

    Escobar, D.; Ospina, R.; Gómez, A.G.; Restrepo-Parra, E.; Arango, P.J.

    2014-02-15

    A detailed microstructural characterization of nanocrystalline TiZrN thin films grown at different substrate temperatures (T{sub S}) was carried out by X-ray diffraction (XRD). Total diffraction pattern modeling based on more meaningful microstructural parameters, such as crystallite size distribution and dislocation density, was performed to describe the microstructure of the thin films more precisely. This diffraction modeling has been implemented and used mostly to characterize powders, but the technique can be very useful to study hard thin films by taking certain considerations into account. Nanocrystalline films were grown by using the cathodic pulsed vacuum arc technique on stainless steel 316L substrates, varying the temperature from room temperature to 200 °C. Further surface morphology analysis was performed to study the dependence of grain size on substrate temperature using atomic force microscopy (AFM). The crystallite and surface grain sizes obtained and the high density of dislocations observed indicate that the films underwent nanostructured growth. Variations in these microstructural parameters as a function of T{sub S} during deposition revealed a competition between adatom mobility and desorption processes, resulting in a specific microstructure. These films also showed slight anisotropy in their microstructure, and this was incorporated into the diffraction pattern modeling. The resulting model allowed for the films' microstructure during synthesis to be better understood according to the experimental results obtained. - Highlights: • Mobility and desorption competition generates a critical temperature. • A microstructure anisotropy related to the local strain was observed in thin films. • Adatom mobility and desorption influence grain size and microstrain.

  6. Structural, vibrational and dielectric studies of (0.95)Pb(Zr{sub x}Ti{sub 1?x})O{sub 3}-(0.05)BiFeO{sub 3} nanoceramics

    SciTech Connect (OSTI)

    Sharma, Subhash, E-mail: rk.dwivedi@jiit.ac.in; Singh, Vikash, E-mail: rk.dwivedi@jiit.ac.in; Dwivedi, R. K., E-mail: rk.dwivedi@jiit.ac.in [Department of Physics and Materials Science and Engineering, Jaypee Institute of Information Technology, Noida- 201307 (India)

    2014-04-24

    (0.95)Pb(Zr{sub x}Ti{sub 1?x})O{sub 3}-(0.05)BiFeO{sub 3} nanoceramics with x=0.51, 0.53 and 0.55 were synthesized by sol-gel route. Rietveld refined X-ray powder diffraction pattern of the samples confirm the single phase formation of compounds with tetragonal structure (P4mm). FT-IR studies revealed that slight shift of phonon modes towards the lower wave number and increase in the bond length with increasing Zr{sup 4+} concentration. Room temperature dielectric properties of system revealed that relaxor characteristics of these samples. Ferroelectric hysteresis curve shows the decrease in polarization values with Zr concentration.

  7. Thickness dependence of magnetoelectric response for composites of Pb(Zr{sub 0.52}Ti{sub 0.48})O{sub 3} films on CoFe{sub 2}O{sub 4} ceramic substrates

    SciTech Connect (OSTI)

    Wang, Jing Zhu, Kongjun; Wu, Xia; Deng, Chaoyong; Peng, Renci; Wang, Jianjun

    2014-08-15

    Using chemical solution spin-coating we grew Pb(Zr{sub 0.52}Ti{sub 0.48})O{sub 3} films of different thicknesses on highly dense CoFe{sub 2}O{sub 4} ceramics. X-ray diffraction revealed no other phases except Pb(Zr{sub 0.52}Ti{sub 0.48})O{sub 3} and CoFe{sub 2}O{sub 4}. In many of these samples we observed typical ferroelectric hysteresis loops, butterfly-shaped piezoelectric strains, and the magnetic-field-dependent magnetostriction. These behaviors caused appreciable magnetoelectric responses based on magnetic-mechanical-electric coupling. Our results indicated that the thickness of the Pb(Zr{sub 0.52}Ti{sub 0.48})O{sub 3} film was important in obtaining strong magnetoelectric coupling.

  8. Comparative study of the electronic structure, phonon spectra, and electron-phonon interaction of ZrB2 and TiB2

    SciTech Connect (OSTI)

    Sichkar, S. M. [Institute of Metal Physics; Antonov, V. N. [Ames Laboratory; Antropov, V. P. [Ames Laboratory

    2013-02-28

    The electronic structure, optical and x-ray absorption spectra, angledependence of the cyclotron masses and extremal cross sections of the Fermisurface, phonon spectra, electron-phonon Eliashberg and transport spectralfunctions, temperature dependence of electrical resistivity of the MB2 (M=Tiand Zr) diborides were investigated from first principles using the fullpotential linear muffin-tin orbital method. The calculations of the dynamicmatrix were carried out within the framework of the linear response theory. Agood agreement with experimental data of optical and x-ray absorption spectra,phonon spectra, electron-phonon spectral functions, electrical resistivity,cyclotron masses and extremal cross sections of the Fermi surface was achieved.

  9. Elastic and inelastic scattering to low-lying states of {sup 58}Ni and {sup 90}Zr using 240-MeV {sup 6}Li

    SciTech Connect (OSTI)

    Krishichayan; Chen, X.; Lui, Y.-W.; Tokimoto, Y.; Button, J.; Youngblood, D. H. [Cyclotron Institute, Texas A and M University, College Station, Texas 77843 (United States)

    2010-01-15

    Elastic and inelastic scattering of 240-MeV {sup 6}Li particles from {sup 58}Ni and {sup 90}Zr were measured with the multipole-dipole-multipole spectrometer from 4 deg. <={theta}{sub c.m.}<=43 deg. The elastic scattering data were fitted with the double-folding model using the density-dependent M3Y NN effective interaction and with a phenomenological Woods-Saxon potential. B(E2) and B(E3) values obtained for low-lying 2{sup +} and 3{sup -} states with the double-folding calculations agreed with the adopted values.

  10. 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.

  11. Investigation of cellular microstructure and enhanced coercivity in sputtered Sm{sub 2}(CoCuFeZr){sub 17} film

    SciTech Connect (OSTI)

    Bhatt, Ranu Schütz, G.; Bhatt, Pramod

    2014-03-14

    We have investigated the effect of annealing temperature on the microstructure and magnetic properties of Sm{sub 2}(CoCuFeZr){sub 17} films prepared using ion beam sputtering at room temperature. The as-deposited film shows randomly oriented polycrystalline grains and exhibits small coercivity (H{sub C}) of 0.04 T at room temperature. Post annealing of these films at 700?°C under Ar atmosphere shows significant changes in the microstructure transforming it to the development of cellular growth, concomitant with enhanced coercivity up to 1.3 T. The enhanced coercivity is explained using the domain wall pinning mechanism.

  12. Production of $^{93,94,95,96}$Tc through $^{7}$Li+$^{nat}$Zr and $^{9}$Be+$^{nat}$Y reactions: Measurement of excitation functions

    E-Print Network [OSTI]

    Moumita Maiti; Susanta Lahiri

    2009-02-25

    For the first time two separate production routes of Tc radionuclides have been studied bombarding $^{7}$Li on $^{nat}$Zr and $^{9}$Be on $^{89}$Y. Excitation functions of the evaporation residues produced in those reactions have been measured using stacked-foil technique followed by the $\\gamma$-spectrometric studies in the energy range 37-45 MeV and 30-48 MeV respectively. Measured excitation functions have been compared with those calculated using the nuclear reaction model codes PACE-II and ALICE91. Experimental results show good agreement with the theoretical predictions. Compound nuclear reaction is the key mechanism in producing evaporation residues.

  13. The structural and in-plane dielectric/ferroelectric properties of the epitaxial (Ba, Sr)(Zr, Ti)O{sub 3} thin films

    SciTech Connect (OSTI)

    Chan, N. Y., E-mail: ngaiyuichan@gmail.com; Wang, Y.; Chan, H. L. W. [Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China); Wang, D. Y. [School of Materials Science and Engineering, The University of New South Wales, Sydney, New South Wales 2052 (Australia); Dai, J. Y. [Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China); Shenzhen Research Institute, The Hong Kong Polytechnic University (China)

    2014-06-21

    Epitaxial (Ba{sub 1-x}Sr{sub x})(Zr{sub 0.1}Ti{sub 0.9})O{sub 3} (BSZT, x?=?0 – 0.45) thin films were deposited on (LaAlO{sub 3}){sub 0.3}(Sr{sub 2}AlTaO{sub 6}){sub 0.35} (LSAT) substrates by pulsed laser deposition. The experimental results demonstrate that the structural, dielectric, and ferroelectric properties of the BSZT thin films were greatly dependent on the strontium content. The BSZT thin films transformed from tetragonal to cubic phase when x???0.35 at room temperature. The Curie temperature and room-temperature remnant polarization decrease with increasing strontium concentration. The optimal dielectric properties were found in (Ba{sub 0.55}Sr{sub 0.45})(Zr{sub 0.1}Ti{sub 0.9})O{sub 3} thin films which is in paraelectric state, having tunability of 47% and loss tangent of 0.0338 under an electric field of 20 MV/m at 1?MHz. This suggests that BSZT thin film is a promising candidate for tunable microwave device applications.

  14. Microstructure and properties of rapidly solidified beryllium-transition metal alloys. [With small amounts of Ti, Zr and Y (1-3 wt %)

    SciTech Connect (OSTI)

    Jacobson, L.A.; Richardson, S.

    1988-01-01

    Alloys of beryllium with small amounts of Ti, Zr and Y (1-3 wt %) were rapidly solidified using an arc hammer splat technique. Each of these elements forms a dilute eutectic with beryllium, and has very low solid solubility in the alpha phase. In the case of Ti, the Be-rich compound is TiBe/sub 12/, and for Zr and Y, the compound is MBe. The objective of the work was to achieve a fine, uniform dispersion of particles of the intermetallic compound. Since these compounds have very high melting points, it was expected that rapidly solidified microstructures would be relatively stable at elevated temperatures. This microstructural stability should result in improved high temperature properties for the alloys. Microstructures have been characterized using optical, scanning and transmission electron microscopy. Microhardness measurements have been made in order to determine the effects of rapid solidification and to evaluate the effects of high temperature exposure on microstructural stability and property retention. The results will be presented in light of the potential of these alloys for intermediate temperature application. 12 refs., 8 figs.

  15. Direct observation of intrinsic piezoelectricity of Pb(Zr,Ti)O{sub 3} by time-resolved x-ray diffraction measurement using single-crystalline films

    SciTech Connect (OSTI)

    Fujisawa, Takashi; Ehara, Yoshitaka; Yasui, Shintaro; Kamo, Takafumi; Funakubo, Hiroshi; Yamada, Tomoaki; Sakata, Osami

    2014-07-07

    Lead zirconate titanate, Pb(Zr,Ti)O{sub 3} or PZT, is one of the most widely investigated ferroelectric and piezoelectric materials due to its superior properties. However, the intrinsic properties of PZT have not been directly measured due to the lack of fabrication of single crystals even though a basic understanding of intrinsic properties has been of interest developing lead-free piezoelectric materials. We demonstrated the direct observation of the intrinsic piezoelectric property by means of the detection of electric-field induced crystal lattice distortion of thick Pb(Zr{sub 0.35}Ti{sub 0.65})O{sub 3} single-crystalline films with single polar-axis orientation and negligible residual strain using the time-resolved X-ray diffraction (XRD) together with the polarization response. Consequently, the effective converse piezoelectric response was experimentally revealed; hence, the electrostrictive coefficient, which is the conversion coefficient between the electrical and mechanical response, was determined. The obtained effective electrostrictive coefficient was 5.2–6.3?×?10{sup ?2} m{sup 4}/C{sup 2}, which agrees with theoretical prediction.

  16. Transformability of t-ZrO{sub 2} and lattice parameters in plasma sprayed rare-earth oxides stabilized zirconia coatings

    SciTech Connect (OSTI)

    Khor, K.A.; Yang, J.

    1997-11-01

    Coatings of zirconia alloys are mostly used in high-temperature environments as thermal barrier coatings (TBC) to fight hostile working environments and boost energy efficiency. CaO, MgO and Y{sub 2}O{sub 3} are added into zirconia to stabilize the cubic and tetragonal forms and prevent catastrophic cracking as a result of the volume changes on t {r_arrow} m transformation. However, zirconia fully stabilized with either CaO or MgO has been shown to be destabilized on thermal cycling over 1,000 C. Y{sub 2}O{sub 3} stabilized ZrO{sub 2} is stable towards vaporization at high temperature (1,200 C). However, it also encounters the problem of destabilization when it is attacked by the mineral constituents in fuel oil. The destabilization resulted in a detrimental volume change of 3--5%, which can lead to failure, especially if thermal cycling across the transformation temperature takes place. Previous studies on the rare-earth oxide-zirconia system used solid state reaction of mixed powders that are likely to yield chemical inhomogeneities. Recent studies on rapid solidified ZrO{sub 2}-Y{sub 2}O{sub 3} and rare earth oxides stabilized zirconia systems by a hammer and anvil apparatus, which claims to be capable of obtaining compositional homogeneities, suggest the formation of a t{prime} phase that is non-transformable.

  17. Transverse spin freezing in a F e x Zr 100x studied using SR D.H. Ryan, 1 J.M. Cadogan, 2 and J. van Lierop 1

    E-Print Network [OSTI]

    Ryan, Dominic

    Transverse spin freezing in a F e x Zr 100x studied using #22;SR D.H. Ryan, 1 J.M. Cadogan, 2 and J #22;SR signatures of transverse spin freezing provides a clear con#12;rmation of predictions from isotropic spin freezing and neither net magnetisation nor long range order. At lower levels of frustration

  18. Transverse spin freezing in ruthenium-doped a-Fe90Zr10 Physics Department and Centre for the Physics of Materials, McGill University, 3600 University Street,

    E-Print Network [OSTI]

    Ryan, Dominic

    Transverse spin freezing in ruthenium-doped a-Fe90Zr10 D. H. Ryan Physics Department and Centre at Tc , followed by transverse spin freezing at Txy . Comparison with earlier Mo¨ssbauer data shows that the break in Bhf(T) is indeed due to transverse spin freezing, and that both Mo¨ssbauer spectroscopy and SR

  19. Muon spin resonance study of transverse spin freezing in a-FexZr100x Department of Physics and Centre for the Physics of Materials, McGill University, 3600 University Street,

    E-Print Network [OSTI]

    Ryan, Dominic

    Muon spin resonance study of transverse spin freezing in a-FexZr100Àx D. H. Ryan Department transition at Tc followed by transverse spin freezing at Txy . We have confirmed the presence of a peak of exchange frustration. In extreme cases, a spin glass is formed with random isotropic spin freezing

  20. In-Situ Control of BaZrO3 and BaSnO3 Nanorod Alignment and Microstructure in YBa2Cu3O7-x Thin Films by Strain Modulated Growth

    E-Print Network [OSTI]

    Baca, Francisco Javier A.

    2009-11-20

    density, Jc. Vortex pinning by the insertion of non-superconducting oxides like BaZrO3 (BZO) or BaSnO3 (BSO) into the YBCO matrix is an effective means of addressing this problem since these defects self-assemble into columnar structures (nanorods...

  1. In situ growth of ZrO{sub 2}–Al{sub 2}O{sub 3} nano-crystalline ceramic coatings via micro arc oxidation of aluminum substrates

    SciTech Connect (OSTI)

    Shoaei-Rad, V.; Bayati, M.R.; Zargar, H.R.; Javadpour, J.; Golestani-Fard, F.; Center of Excellence for Advanced Materials, Iran University of Science and Technology, P.O. Box 16845-195, Tehran

    2012-06-15

    Highlights: ? ZrO{sub 2}–Al{sub 2}O{sub 3} layers were fabricated by MAO process. ? A formation mechanism was also proposed. ? Effect of voltage and electrolyte composition on layers properties was studied. -- Abstract: Micro arc oxidation technique was employed to grow zirconia–alumina porous layers. Considering XPS, XRD, and EDX results, the layers mainly consisted of ?-Al{sub 2}O{sub 3}, ?-Al{sub 2}O{sub 3}, monoclinic ZrO{sub 2}, tetragonal ZrO{sub 2}. Fractions of these phases were observed to change based on the fabrication conditions. Zirconia phases formed not only on the surface, but also in the layers depth. Increasing the voltage as well as utilizing thicker electrolytes resulted in higher zirconium concentration. The average crystalline size of the ZrO{sub 2} and the Al{sub 2}O{sub 3} phases was determined as about 57 and 75 nm. AFM studies revealed that the surface roughness increased with voltage and electrolyte concentration. Morphological evaluations, performed by SEM, showed that the microstructure of the layers strongly depended on the synthesis conditions. The layers revealed a porous structure with a pores size of 40–300 nm. Microcracks were observed to appear when the electrolyte concentration and the applied voltage increased. Finally, a formation mechanism was put forward with emphasis on the chemical and the electrochemical foundations.

  2. Evidence of Eu{sup 2+} 4f electrons in the valence band spectra of EuTiO{sub 3} and EuZrO{sub 3}

    SciTech Connect (OSTI)

    Kolodiazhnyi, T.; Valant, M.; Williams, J. R.; Bugnet, M.; Botton, G. A.; Ohashi, N.; Sakka, Y.

    2012-10-15

    We report on optical band gap and valence electronic structure of two Eu{sup 2+}-based perovskites, EuTiO{sub 3} and EuZrO{sub 3} as revealed by diffuse optical scattering, electron energy loss spectroscopy, and valence-band x-ray photoelectron spectroscopy. The data show good agreement with the first-principles studies in which the top of the valence band structure is formed by the narrow Eu 4f{sup 7} electron band. The O 2p band shows the features similar to those of the Ba(Sr)TiO{sub 3} perovskites except that it is shifted to higher binding energies. Appearance of the Eu{sup 2+} 4f{sup 7} band is a reason for narrowing of the optical band gap in the title compounds as compared to their Sr-based analogues.

  3. Mechanism of tailored magnetic anisotropy in amorphous Co{sub 68}Fe{sub 24}Zr{sub 8} thin films

    SciTech Connect (OSTI)

    Fu, Yu E-mail: cangcangzhulin@gmail.com; Meckenstock, R.; Farle, M.; Barsukov, I.; Lindner, J.; Raanaei, H.; Hjörvarsson, B.

    2014-02-17

    The mechanism of tailored magnetic anisotropy in amorphous Co{sub 68}Fe{sub 24}Zr{sub 8} thin films was investigated by ferromagnetic resonance (FMR) on samples deposited without an applied magnetic field, with an out-of-plane field and an in-plane field. Analysis of FMR spectra profiles, high frequency susceptibility calculations, and statistical simulations using a distribution of local uniaxial magnetic anisotropy reveal the presence of atomic configurations with local uniaxial anisotropy, of which the direction can be tailored while the magnitude remains at an intrinsically constant value of 3.0(2) kJ/m{sup 3}. The in-plane growth field remarkably sharpens the anisotropy distribution and increases the sample homogeneity. The results benefit designing multilayer spintronic devices based on highly homogeneous amorphous layers with tailored magnetic anisotropy.

  4. Process for production of solution-derived (Pb,La)(Nb,Sn,Zr,Ti)O.sub.3 thin films and powders

    DOE Patents [OSTI]

    Boyle, Timothy J. (Albuquerque, NM)

    1999-01-01

    A simple and rapid process for synthesizing (Pb,La)(Nb,Sn,Zr,Ti)O.sub.3 precursor solutions and subsequent ferroelectric thin films and powders of the perovskite phase of these materials has been developed. This process offers advantages over standard methods, including: rapid solution synthesis (<10 minutes), use of commercially available materials, film production under ambient conditions, ease of lanthanum dissolution at high concentrations, and no heating requirements during solution synthesis. For lanthanum-doped ferroelectric materials, the lanthanum source can be added with total synthesis time less than 10 minutes. Films and powders are crystallized at approximately 650.degree. C. and exhibit ferroelectric properties comparable to films and powders produced by other techniques which require higher crystallization temperatures.

  5. Process for production of solution-derived (Pb,La)(Nb,Sn,Zr,Ti)O{sub 3} thin films and powders

    DOE Patents [OSTI]

    Boyle, T.J.

    1999-01-12

    A simple and rapid process for synthesizing (Pb,La)(Nb,Sn,Zr,Ti)O{sub 3} precursor solutions and subsequent ferroelectric thin films and powders of the perovskite phase of these materials has been developed. This process offers advantages over standard methods, including: rapid solution synthesis (<10 minutes), use of commercially available materials, film production under ambient conditions, ease of lanthanum dissolution at high concentrations, and no heating requirements during solution synthesis. For lanthanum-doped ferroelectric materials, the lanthanum source can be added with total synthesis time less than 10 minutes. Films and powders are crystallized at approximately 650 C and exhibit ferroelectric properties comparable to films and powders produced by other techniques which require higher crystallization temperatures. 2 figs.

  6. Understanding the deformation mechanism of individual phases of a ZrTi-based bulk metallic glass matrix composite using in situ diffraction and imaging methods

    SciTech Connect (OSTI)

    Huang, Yongjiang E-mail: yjhuang@hit.edu.cn; Khong, J. C.; Mi, J. E-mail: yjhuang@hit.edu.cn; Connolley, Thomas

    2014-01-20

    The plasticity of a ZrTi-based bulk metallic glass composite consisting of glassy matrix and crystalline dendritic phase was studied in-situ under identical tensile loading conditions using scanning electron microscopy and synchrotron X-ray diffraction. A generic procedure was developed to separate the diffraction information of the crystalline phases away from that of the matrix and to precisely calculate the microscopic strains of the two phases at different macroscopic load steps. In this way, the time-evolved quantitative links between shear bands nucleation/propagation and the corresponding microscopic stress fields around them are established, providing more quantitative understanding on (1) how the shear bands are driven by the local stress field, and (2) the critical stresses required for the shear bands to nucleate in the crystalline phase, propagate through the crystalline/matrix interface, and finally into the matrix.

  7. Enhancement of pyroelectric signal by continuous ultraviolet illumination of epitaxial Pb(Zr{sub 0.2}Ti{sub 0.8})O{sub 3} films

    SciTech Connect (OSTI)

    Pintilie, L.; Iuga, A. [National Institute of Materials Physics, Atomistilor 105bis, Magurele, Ilfov 077125 (Romania); Botea, M. [National Institute of Materials Physics, Atomistilor 105bis, Magurele, Ilfov 077125 (Romania); Faculty of Physics, University of Bucharest, Magurele 077125 (Romania)

    2014-09-29

    The pyroelectric signal generated by an epitaxial Pb(Zr{sub 0.2}Ti{sub 0.8})O{sub 3} film can be enhanced by continuous illumination with ultraviolet (UV) light. The measured signal increases more than 2 times at low modulation frequencies of the incident infrared (IR) radiation (?10?Hz) and at wavelengths where the short-circuit photocurrent presents the maximum value (?280–300?nm). The tentative explanation is that the changes in polarization induced by the temperature variation under modulated IR illumination are generating a variable internal electric field, able to collect the photogenerated carriers produced under continuous UV illumination leading to an additional signal in phase with the pyroelectric one. This finding could be exploited for designing pyroelectric detectors with enhanced characteristics by combining both UV and IR responses.

  8. Phases in ceria-zirconia binary oxide (1-x)CeO2-xZrO2 nanoparticles: the size effects

    SciTech Connect (OSTI)

    Zhang,F.; Chen, C.; Hanson, J.; Herman, I.; Chan, S.

    2006-01-01

    The phases of ceria-zirconia nanoparticles observed in air are studied as a function of particle size and composition by X-ray diffraction, transmission electron microscopy, and Raman spectroscopy. The emergence of two tetragonal phases t{prime}{prime} and t monotonically moves toward higher zirconia concentrations with decreasing particle size. A smaller particle size increases the solubility of zirconia in cubic ceria, while higher zirconia content in ceria stabilizes against coarsening. In particular, the cubic Ce{sub 1-x}Zr{sub x}O{sub 2-y} is persistent and is 8% in phase amount even at 90% zirconia with 33 nm crystal size. Neither the monoclinic phase m nor the tetragonal phase t{prime} is observed in the present nanoparticles (<40 nm). The effectiveness of these nanoparticles as oxygen source-and-sink in catalytic support is largely due to the persistence of the cubic and the t{prime}{prime} phases.

  9. Preparation and characterization on nano-hybrid composite solid polymer electrolyte of PVdF-HFP /MG49-ZrO{sub 2} for battery application

    SciTech Connect (OSTI)

    Lee, T. K.; Ahmad, A. [Polymer Research Center, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor D. E. Malaysia and School of Chemical Sciences and Food Technology, Faculty of Science and Technology (Malaysia); Hasyareeda, N. [School of Chemical Sciences and Food Technology, Faculty of Science and Technology (Malaysia)

    2014-09-03

    Initial study on nano composite polymer electrolyte of PVdF-HFP/MG49-ZrO{sub 2} has been done. The zirconium was synthesis via in-situ sol-gel method in a dissolved polymer blends. The effects of different concentrations of zirconium and pH values have been investigated on nano composite polymer (NCP). Analysis impedance show that only at 6 wt. % of zirconium for all pH values show a semi-circle arc which have lowest value of bulk resistance. No ionic conductivity value is obtain due to the absent of ion charge carriers. Analysis of XRD revealed that crystallinity phase of the nano composite polymer was affect by different pH values. However, no significant changes have been observed in IR bands. This could well indicate that different pH medium did not affect the chemical bonding in the structure.

  10. Dielectric behavior of samarium-doped BaZr{sub 0.2}Ti{sub 0.8}O{sub 3} ceramics

    SciTech Connect (OSTI)

    Li, Yuanliang; Wang, Ranran; Ma, Xuegang; Li, Zhongqiu; Sang, Rongli; Qu, Yuanfang

    2014-01-01

    Graphical abstract: - Highlights: • We investigate dielectric properties and phase transition of Sm{sup 3+}-doped BaZr{sub 0.2}Ti{sub 0.8}O{sub 3} ceramics. • The additive amount of Sm{sub 2}O{sub 3} can greatly affect the dielectric properties. • The materials undergo a diffuse type ferroelectric phase transition. • There is an alternation of substitution preference of Sm{sup 3+} ion for the host cations in perovskite lattice. - Abstract: The dielectric properties and phase transition of Sm{sup 3+}-doped BaZr{sub 0.2}Ti{sub 0.8}O{sub 3} (BZT20) ceramics were investigated. Room temperature X-ray diffraction study suggested that the compositions had single-phase cubic symmetry. Microstructure studies showed that the grain size decreased and that the Sm{sub 2}O{sub 3} amount markedly affected the dielectric properties of BZT20. A dielectric constant of 5700 at 0.2 mol% Sm{sub 2}O{sub 3} and a dissipation factor of only 0.0011 at 2 mol% Sm{sub 2}O{sub 3} were observed, indicating that BZT20 had significant potential applications. Moreover, the dielectric constant, dissipation factor, phase-transition temperature, and maximum dielectric constant increased with increased Sm{sub 2}O{sub 3} amount at ?0.2 mol% Sm{sub 2}O{sub 3} but decreased with increased Sm{sub 2}O{sub 3} amount at >0.2 mol% Sm{sub 2}O{sub 3}.

  11. Synchrotron Radiation Photoemission Spectroscopic Study of Band Offsets and Interface Self-cleaning by Atomic Layer Deposited HfO2 on In0.53Ga0.47As and In0.52Al0.48As

    SciTech Connect (OSTI)

    Kobayashi, Masaharu; /SLAC, SSRL; Chen, P.T.; Sun, Y.; Goel, N.; Majhi, P.; Garner, M; Tsai, W.; Pianetta, P.; Nishi, Y.; /SLAC, SSRL

    2008-10-31

    The Synchrotron Radiation Photoemission Spectroscopic (SRPES) study was conducted to (a) investigate the surface chemistry of In{sub 0.53}Ga{sub 0.47}As and In{sub 0.52}Al{sub 0.48}As post chemical and thermal treatments, (b) construct band diagram and (c) investigate the interface property of HfO{sub 2}/In{sub 0.53}Ga{sub 0.47}As and HfO{sub 2}/In{sub 0.52}Al{sub 0.48}As. Dilute HCl and HF etch remove native oxides on In{sub 0.53}Ga{sub 0.47}As and In{sub 0.52}Al{sub 0.47}As, whereas in-situ vacuum annealing removes surface arsenic pile-up. After the atomic layer deposition of HfO{sub 2}, native oxides were considerably reduced compared to that in as-received epi-layers, strongly suggesting the self-clean mechanism. Valence and conduction band offsets are measured to be 3.37 {+-} 0.1eV, 1.80 {+-} 0.3eV for In{sub 0.53}Ga{sub 0.47}As and 3.00 {+-} 0.1eV, 1.47 {+-} 0.3eV for In{sub 0.52}Al{sub 0.47}As, respectively.

  12. Sub-250?nm low-threshold deep-ultraviolet AlGaN-based heterostructure laser employing HfO{sub 2}/SiO{sub 2} dielectric mirrors

    SciTech Connect (OSTI)

    Kao, Tsung-Ting; Liu, Yuh-Shiuan; Mahbub Satter, Md.; Li, Xiao-Hang; Lochner, Zachary; Douglas Yoder, P.; Detchprohm, Theeradetch; Dupuis, Russell D.; Shen, Shyh-Chiang Ryou, Jae-Hyun; Fischer, Alec M.; Wei, Yong; Xie, Hongen; Ponce, Fernando A.

    2013-11-18

    We report a sub-250-nm, optically pumped, deep-ultraviolet laser using an Al{sub x}Ga{sub 1?x}N-based multi-quantum-well structure grown on a bulk Al-polar c-plane AlN substrate. TE-polarization-dominant lasing action was observed at room temperature with a threshold pumping power density of 250?kW/cm{sup 2}. After employing high-reflectivity SiO{sub 2}/HfO{sub 2} dielectric mirrors on both facets, the threshold pumping power density was further reduced to 180?kW/cm{sup 2}. The internal loss and threshold modal gain can be calculated as 2?cm{sup ?1} and 10.9?cm{sup ?1}, respectively.

  13. Enhancement in the transport critical current density J{sub c} in YBa{sub 2}Cu{sub 3}O{sub 7??} added with an insulating nano crystalline YBa{sub 2}HfO{sub 5.5} perovskite

    SciTech Connect (OSTI)

    Rejith, P. P.; Vidya, S.; Thomas, J. K. [Electronic Materials Research Laboratory, Department of Physics, Mar Ivanios College, Thiruvananthapuram- 695 015, Kerala (India); Solomon, Sam [Department of Physics, St. John's College, Anchal-691306, Kerala (India)

    2014-01-28

    When a magnetic field is applied to type II superconductors, such as YBa{sub 2}Cu{sub 3}0{sub 7??} (YBCO), the flux quanta penetrate the material as a regular array of vortices. However when transport currents are applied, they act to move these vortices, thus lowers the critical current density (J{sub c}) as well as destroying superconductivity. The development of microstructures made of YBCO materials has enabled engineers to increase the critical current density, within Type II materials by introducing flux pinning centres into the material. The microstructure and flux pinning properties of YBa{sub 2}Cu{sub 3}O{sub 7??} system with varying levels (0-5 wt. %) of a nano perovskite ceramic insulator; YBa{sub 2}HfO{sub 5.5} addition was studied in detail. Orthorhombic YBa{sub 2}Cu{sub 3}O{sub 7??} powder was prepared through conventional solid state route and a modified combustion method was used for synthesizing nanocrystalline YBa{sub 2}HfO{sub 5.5}. The structure and microstructure of the samples examined by X-ray diffraction and scanning electron microscopy showed that YBa{sub 2}HfO{sub 5.5} and YBCO remained unreacted even at higher processing temperature without deteriorating the superconducting properties. The scanning electron microscope image shows that YBa{sub 2}HfO{sub 5.5} forms an electrical-network between grains. These observations suggest that the YBa{sub 2}HfO{sub 5.5} addition to the Y-123-compounds improve the electrical connection between superconducting grains and substantial improvements in the relative electrical transport properties of the composites. The variation of sintering temperature, density, critical transition temperature (T{sub c}) and magnetic field dependence of critical current density (J{sub c}) of YBa{sub 2}Cu{sub 3}O{sub 7??} having different proportions of YBa{sub 2}HfO{sub 5.5} in the matrix were also studied in detail. It is found that the addition of these elements considerably enhances the flux pinning strength of the system, and there is also an increase of critical temperature (T{sub c}) and critical current density (J{sub c}) up to an optimum value of 8.76 × 10{sup 4} A/cm{sup 2} for a concentration of 2 wt % addition of nano YBa{sub 2}HfO{sub 5.5}. The enhancement of the critical current density in the YBa{sub 2}Cu{sub 3}O{sub 7??} - YBa{sub 2}HfO{sub 5.5} samples is attributed to the sustained formation of the insulating and non-reacting YBa{sub 2}HfO{sub 5.5} phase acting as pinning center. The addition of YBa{sub 2}HfO{sub 5.5} in YBa{sub 2}Cu{sub 3}O{sub 7??} bulk superconductor also enhances the pinning force density from 3 ×10{sup 6} N/m{sup 3} to 69.6 × 10{sup 6}N/m{sup 3} at 77 K.

  14. Atomic Layer Deposition Enabled Synthesis of Multiferroic Nanostructures

    E-Print Network [OSTI]

    Pham, Calvin Dinh-Tu

    2015-01-01

    Thin Films by Atomic Layer Deposition." Advanced FunctionalPlasma enhanced atomic layer deposition of HfO 2 and ZrO 2et al. (2003). "Atomic Layer Deposition (ALD) of Bismuth

  15. Effect of the valence electron concentration on the bulk modulus and chemical bonding in Ta{sub 2}AC and Zr{sub 2}AC (A=Al, Si, and P)

    SciTech Connect (OSTI)

    Schneider, Jochen M.; Music, Denis; Sun Zhimei

    2005-03-15

    We have studied the effect of the valence electron concentration, on the bulk modulus and the chemical bonding in Ta{sub 2}AC and Zr{sub 2}AC (A=Al, Si, and P) by means of ab initio calculations. Our equilibrium volume and the hexagonal ratio (c/a) agree well (within 2.7% and 1.2%, respectively) with previously published experimental data for Ta{sub 2}AlC. The bulk moduli of both Ta{sub 2}AC and Zr{sub 2}AC increase as Al is substituted with Si and P by 13.1% and 20.1%, respectively. This can be understood since the substitution is associated with an increased valence electron concentration, resulting in band filling and an extensive increase in cohesion.

  16. Microstructural and dielectric properties of Ba{sub 0.6}Sr{sub 0.4}Ti{sub 1-x}Zr{sub x}O{sub 3} based combinatorial thin film capacitors library

    SciTech Connect (OSTI)

    Liu Guozhen; Wolfman, Jerome; Autret-Lambert, Cecile; Sakai, Joe; Roger, Sylvain; Gervais, Monique; Gervais, Francois [Laboratoire d'Electrodynamique des Materiaux Avances (LEMA), UMR 6157 CNRS/CEA, Universite Francois Rabelais, Parc de Grandmont, 37200 Tours (France)

    2010-12-01

    Epitaxial growth of Ba{sub 0.6}Sr{sub 0.4}Ti{sub 1-x}Zr{sub x}O{sub 3} (0{<=}x{<=}0.3) composition spread thin film library on SrRuO{sub 3}/SrTiO{sub 3} layer by combinatorial pulsed laser deposition (PLD) is reported. X-ray diffraction and energy dispersive x-ray spectroscopy studies showed an accurate control of the film phase and composition by combinatorial PLD. A complex evolution of the microstructure and morphology with composition of the library is described, resulting from the interplay between epitaxial stress, increased chemical pressure, and reduced elastic energy upon Zr doping. Statistical and temperature-related capacitive measurements across the library showed unexpected variations in the dielectric properties. Doping windows with enhanced permittivity and tunability are identified, and correlated to microstructural properties.

  17. Electron-irradiation induced phase transformation in La{sub 1/3}Zr{sub 2}(PO{sub 4}){sub 3}: La{sup 3+} displacement in a preserved NASICON framework

    SciTech Connect (OSTI)

    Crosnier-Lopez, M.P. . E-mail: marie-pierre.crosnier-lopez@univ-lemans.fr; Barre, M.; Le Berre, F.; Fourquet, J.L.

    2006-08-15

    The La{sub 1/3}Zr{sub 2}(PO{sub 4}){sub 3} NASICON-type compound (S.G. P3-bar - neutron and X-ray diffraction experiments) is investigated by transmission electron microscopy (TEM) technique, selected area electron diffraction (SAED) and high-resolution electron microscopy (HREM), in order to study locally the lanthanum distribution. An irreversible structural transformation (P-bar -bar -bar ->P-bar c-bar ->R-bar -bar -bar ) is observed, without modification of the atomic content and cell size, as soon as the phase is illuminated by the electron beam. The progressive disappearance of the spots which do not check the R conditions on the SAED patterns is clearly shown along two zone axis, [001] and [100]. This transformation implies the displacement of the two La{sup 3+} cations in a preserved classical [Zr{sub 2}(PO{sub 4}){sub 3}]{sup -} network. This interesting behavior is in good agreement with the La{sup 3+} ionic conductivity observed in La{sub 1/3}Zr{sub 2}(PO{sub 4}){sub 3} (4.09x10{sup -7}Scm{sup -1} at 700 deg. C). To our knowledge, this is the first time that a complete TEM study is done on a NASICON-type phase.

  18. Lifetime measurements of microsecond isomers in the N=48 nuclei {sup 88}Zr and {sup 90}Mo using recoil-isomer tagging

    SciTech Connect (OSTI)

    Chakraborty, A.; Krishichayan; Ghugre, S.S.; Goswami, R.; Mukhopadhyay, S.; Pattabiraman, N.S.; Ray, S.; Sinha, A.K.; Sarkar, S.; Madhusudhana Rao, P.V.; Garg, U.; Basu, S.K.; Chaturvedi, L.; Dhal, A.; Sinha, R.K.; Govil, I.M.; Chatterjee, M.B.; Sarkar, M. Saha; Bhowmik, R.K.; Jhingan, A. [Inter University Consortium for DAE Facilities, Calcutta Center, Sector III/LB-8, Bidhan Nagar, Kolkata 700098 (India); Department of Physics, University of Burdwan, Burdwan 713104 (India); Department of Nuclear Physics, Andhra University, Waltair 530003 (India); Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Variable Energy Cyclotron Center, Sector-I/AF, Bidhan Nagar, Kolkata 700064 (India); Department of Physics, Banaras Hindu University, Varanasi 221005 (India); Department of Physics, Panjab University, Chandigarh 160014 (India); Saha Institute of Nuclear Physics, Sector-I/AF, Bidhan Nagar, Kolkata 700064 (India); Nuclear Science Center, Aruna Asaf Ali Marg, New Delhi 110067 (India)] [and others

    2004-07-01

    The recoil-isomer tagging technique has been used to study the isomeric states of nuclei in the vicinity of the N=50 shell closure. The nuclei of interest were separated from the projectilelike nuclei and other evaporation residues and transported to the focal plane of a recoil separator. The decay of the tagged isomer was studied at the focal plane using a high-purity Ge detector. The prompt transitions feeding the isomer were detected in an array of Clover Ge detectors placed around the target. The measured half-lives of the 8{sup +} isomers in {sup 88}Zr and {sup 90}Mo are 1.41{sub (-0.09)}{sup (+0.12)} {mu}s and 1.17{sub (-0.07)}{sup (+0.19)} {mu}s, respectively. The corresponding transition probabilities are in reasonable agreement with the predictions of shell model calculations. The systematics of effective charges (e{sub p} and e{sub n}) for N=48 nuclei are qualitatively understood in these calculations.

  19. Possible contribution of low shear modulus C?? to the low Young’s modulus of Ti-36Nb-5Zr alloy

    SciTech Connect (OSTI)

    Meng, Qingkun; Guo, Shun; Ren, Xiaobing; Xu, Huibin; Zhao, Xinqing

    2014-09-29

    Despite the importance of single-crystal elastic constants of ?-phase titanium alloys in understanding their low Young's modulus—a property crucial for many applications, such data are often difficult to obtain when the alloy composition is close to the instability limit of the ? phase, where the presence of ?" martensite precludes the fabrication of ?-phase single crystal. In the present study, we extracted the single-crystal elastic constants of such a ?-phase titanium alloy with low Young's modulus, Ti-36Nb-5Zr (wt. %), from polycrystalline specimens by using an in-situ synchrotron X-ray diffraction technique. It is indicated that the low Young's modulus of the alloy originates from the anomalously low shear modulus C?? as well as the low shear modulus C', which is different from a common viewpoint that the Young's modulus of ?-phase titanium alloys is dominantly controlled by the C'. This suggests that low C?? is an important contributor to low Young's modulus for instable ?-phase titanium alloys.

  20. Possible contribution of low shear modulus C{sub 44} to the low Young's modulus of Ti-36Nb-5Zr alloy

    SciTech Connect (OSTI)

    Meng, Qingkun; Xu, Huibin; Zhao, Xinqing; Guo, Shun; Ren, Xiaobing

    2014-09-29

    Despite the importance of single-crystal elastic constants of ?-phase titanium alloys in understanding their low Young's modulus—a property crucial for many applications, such data are often difficult to obtain when the alloy composition is close to the instability limit of the ? phase, where the presence of ?' martensite precludes the fabrication of ?-phase single crystal. In the present study, we extracted the single-crystal elastic constants of such a ?-phase titanium alloy with low Young's modulus, Ti-36Nb-5Zr (wt.?%), from polycrystalline specimens by using an in-situ synchrotron X-ray diffraction technique. It is indicated that the low Young's modulus of the alloy originates from the anomalously low shear modulus C{sub 44} as well as the low shear modulus C?, which is different from a common viewpoint that the Young's modulus of ?-phase titanium alloys is dominantly controlled by the C?. This suggests that low C{sub 44} is an important contributor to low Young's modulus for instable ?-phase titanium alloys.

  1. Lasing characteristics of ZrO{sub 2}–Y{sub 2}O{sub 3}–Ho{sub 2}O{sub 3} crystal

    SciTech Connect (OSTI)

    Borik, M A; Lomonova, E E; Kulebyakin, A V; Ushakov, S N; Lyapin, A A; Ryabochkina, P A; Chabushkin, A N

    2013-09-30

    The spectral dependences of the gain cross section of the {sup 5}I{sub 8} ? {sup 5}I{sub 7}, {sup 5}I{sub 7} ? {sup 5}I{sub 8} transition of Ho{sup 3+} ions in the ZrO{sub 2} – 13.6 mol % Y{sub 2}O{sub 3} – 0.4 mol % Ho{sub 2}O{sub 3} crystal are calculated at different relative population inversions using the absorption and luminescence spectra of the {sup 5}I{sub 8} ? {sup 5}I{sub 7} and {sup 5}I{sub 7} ? {sup 5}I{sub 8} transitions of Ho{sup 3+} ions at T=''300'' K. Lasing of these crystals at the {sup 5}I{sub 7} ? {sup 5}I{sub 8} transition is obtained for the first time under pumping by a Tm : YLiF{sub 4} laser (?{sub p} = 1.905 ?m). The lasing wavelength is 2.17 ?m. (lasers)

  2. One-step electrochemical deposition of a graphene-ZrO2 nanocomposite: Preparation, characterization and application for detection of organophosphorus agents

    SciTech Connect (OSTI)

    Du, Dan; Liu, Juan; Zhang, Xiao-Yan; Cui, Xiao-Li; Lin, Yuehe

    2011-04-27

    This paper described the preparation, characterization, and electrochemical properties of a graphene-ZrO2 nanocomposite (GZN) and its application for both the enrichment and detection of methyl parathion (MP). GZN was fabricated using electrochemical deposition and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), which showed the successful formation of nanocomposites. Due to the strong affinity to the phosphoric group and the fast electron-transfer kinetics of GZN, both the extraction and electrochemical detection of organophosphorus (OP) agents at the same GZN modified electrochemical sensor was possible. The combination of solid-phase extraction and stripping voltammetric analysis allowed fast, sensitive, and selective determination of MP in garlic samples. The stripping response was highly linear over the MP concentrations ranging from 0.5 ng mL?1 to 100 ng mL?1, with a detection limit of 0.1 ng mL?1. This new nanocomposite-based electrochemical sensor provides an opportunity to develop a field-deployable, sensitive, and quantitative method for monitoring exposure to OPs.

  3. Ion beam-assisted pulsed laser deposition of (Ba,Sr)(Ti,Zr)O{sub 3} films on Pt-Si substrates

    SciTech Connect (OSTI)

    Sakai, Joe; Vayunandana Reddy, Y. K.; Autret-Lambert, Cecile; Lagrange, Jean-Francois; Motret, Olivier; Roger, Sylvain; Wolfman, Jerome [Laboratoire LEMA, UMR 6157 CNRS-CEA, Universite Francois Rabelais de Tours, Parc de Grandmont, 37200 Tours (France)

    2011-05-15

    Ion beam-assisted pulsed laser deposition with an Ar-oxygen ion mixture was used to prepare Ba{sub 0.6}Sr{sub 0.4}Ti{sub 0.7}Zr{sub 0.3}O{sub 3} (BSTZ) thin films on Pt-coated Si substrates. The ion beam with an anode voltage of 600 V was effective to reduce the thermal budget, i.e., to achieve similar crystallinity with approximately 100 deg. C lower deposition temperature compared to the cases without ionization. It was revealed that the dielectric properties (relative dielectric constant {epsilon}{sub r} and its electric field tunability), out-of-plane lattice parameter of (001)-oriented grains (a{sub 001}), and the existence of (110)-oriented grains are correlated with one another. Elongation of a{sub 001} was suppressed, resulting in large {epsilon}{sub r} values comparable with that of a ceramic bulk of the same composition, in the BSTZ films that contain (110)-oriented grains. Less volume of amorphous BSTZ region is supposed to be playing an important role for the bulklike properties of these BSTZ films.

  4. Analysis of beta-decay rates for Ag 108, Ba 133, Eu 152, Eu 154, Kr 85, Ra 226, and Sr 90, measured at the Physikalisch-Technische Bundesanstalt from 1990 to 1996

    SciTech Connect (OSTI)

    Sturrock, P. A. [Center for Space Science and Astrophysics, Stanford University, Stanford, CA 94305 (United States); Fischbach, E. [Department of Physics and Astronomy, Purdue University, West Lafayette, IN 47907 (United States); Jenkins, J. [Department of Nuclear Engineering, Texas A and M University, College Station, TX 77843 (United States)

    2014-10-10

    We present the results of an analysis of measurements of the beta-decay rates of Ag 108, Ba 133, Eu 152, Eu 154, Kr 85, Ra 226, and Sr 90 acquired at the Physikalisch-Technische Bundesanstalt from 1990 through 1995. Although the decay rates vary over a range of 165 to 1 and the measured detector current varies over a range of 19 to 1, the detrended and normalized count rate measurements exhibit a sinusoidal annual variation with amplitude in the small range 0.068%-0.088% (mean 0.081%, standard deviation 0.0072%, a rejection of the zero-amplitude hypothesis) and phase-of-maximum in the small range 0.062-0.083 (January 23 to January 30). In comparing these results with those of other related experiments that yield different results, it may be significant that this experiment, at a standards laboratory, seems to be unique in using a 4? detector. These results are compatible with a solar influence, and do not appear to be compatible with an experimental or environmental influence. It is possible that Ba 133 measurements are also subject to a non-solar (possibly cosmic) influence.

  5. Improving the mechanical properties of Zr-based bulk metallic glass by controlling the activation energy for ?-relaxation through plastic deformation

    SciTech Connect (OSTI)

    Adachi, Nozomu; Todaka, Yoshikazu, E-mail: todaka@me.tut.ac.jp; Umemoto, Minoru [Department of Mechanical Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku, Toyohashi, Aichi 441-8580 (Japan); Yokoyama, Yoshihiko [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan)

    2014-09-29

    The mechanism of plastic deformation in bulk metallic glasses (BMGs) is widely believed to be based on a shear transformation zone (STZ). This model assumes that a shear-induced atomic rearrangement occurs at local clusters that are a few to hundreds of atoms in size. It was recently postulated that the potential energy barrier for STZ activation, W{sub STZ}, calculated using the cooperative shear model, is equivalent to the activation energy for ?-relaxation, E{sub ?}. This result suggested that the fundamental process for STZ activation is the mechanically activated ?-relaxation. Since the E{sub ?} value and the glass transition temperature T{sub g} of BMGs have a linear relation, that is, because E{sub ?}???26RT{sub g}, the composition of the BMG determines the ease with which the STZ can be activated. Enthalpy relaxation experiments revealed that the BMG Zr{sub 50}Cu{sub 40}Al{sub 10} when deformed by high-pressure torsion (HPT) has a lower E{sub ?} of 101?kJ/mol. The HPT-processed samples accordingly exhibited tensile plastic elongation (0.34%) and marked decreases in their yield strength (330?MPa). These results suggest that mechanically induced structural defects (i.e., the free volume and the anti-free volume) effectively act to reduce W{sub STZ} and increase the number of STZs activated during tensile testing to accommodate the plastic strain without requiring a change in the composition of the BMG. Thus, this study shows quantitatively that mechanically induced structural defects can overcome the compositional limitations of E{sub ?} (or W{sub STZ}) and result in improvements in the mechanical properties of the BMG.

  6. Dynamic response of Cu4Zr54 metallic glass to high strain rate shock loading: plasticity, spall and atomic-level structures

    SciTech Connect (OSTI)

    Luo, Shengnian; Arman, Bedri; Germann, Timothy C; Cagin, Tahir

    2009-01-01

    We investigate dynamic response of Cu{sub 46}Zr{sub 54} metallic glass under adiabatic planar shock wave loading (one-dimensional strain) wjth molecular dynamics simulations, including Hugoniot (shock) states, shock-induced plasticity and spallation. The Hugoniot states are obtained up to 60 CPa along with the von Mises shear flow strengths, and the dynamic spall strength, at different strain rates and temperatures. The spall strengths likely represent the limiting values achievable in experiments such as laser ablation. For the steady shock states, a clear elastic-plastic transition is identified (e.g., in the shock velocity-particle velocity curve), and the shear strength shows strain-softening. However, the elastic-plastic transition across the shock front displays transient stress overshoot (hardening) above the Hugoniot elastic limit followed by a relatively sluggish relaxation to the steady shock state, and the plastic shock front steepens with increasing shock strength. The local von Mises shear strain analysis is used to characterize local deformation, and the Voronoi tessellation analysis, the corresponding short-range structures at various stages of shock, release, tension and spallation. The plasticity in this glass is manifested as localized shear transformation zones and of local structure rather than thermal origin, and void nucleation occurs preferentially at the highly shear-deformed regions. The Voronoi and shear strain analyses show that the atoms with different local structures are of different shear resistances that lead to shear localization (e.g., the atoms indexed with (0,0,12,0) are most shear-resistant, and those with (0,2,8,1) are highly prone to shear flow). The dynamic changes in local structures are consistent with the observed deformation dynamics.

  7. Preparation and spectroscopic properties of rare-earth (RE) (RE = Sm, Eu, Tb, Dy, Tm)-activated K{sub 2}LnZr(PO{sub 4}){sub 3} (Ln = Y, La, Gd and Lu) phosphate in vacuum ultraviolet region

    SciTech Connect (OSTI)

    Zhang, Zhi-Jun; Lin, Xiao; Graduate School of Chinese Academy of Science, Beijing, 100039 ; Zhao, Jing-Tai; Zhang, Guo-Bin

    2013-02-15

    Graphical abstract: Display Omitted Highlights: ? We report the VUV spectroscopic properties of rare-earth ions in K{sub 2}LnZr(PO{sub 4}){sub 3}. ? The O{sup 2?}-Eu{sup 3+} charge transfer bands at about 220 nm have been observed. ? The 4f–5d spin-allowed and spin-forbidden transitions of Tb{sup 3+} have been observed. ? There is energy transfer between the host and rare-earth activators. -- Abstract: Rare earth (RE = Sm, Eu, Tb, Dy and Tm)-activated K{sub 2}LnZr(PO{sub 4}){sub 3} (Ln = Y, La, Gd and Lu) have been synthesized by solid-state reaction method, and their vacuum ultraviolet (VUV) excitation luminescent characteristics have been investigated. The band in the wavelength range of 130–157 nm and the other one range from 155 to 216 nm with the maximum at about 187 nm in the VUV excitation spectra of these compounds are attributed to the host lattice absorption and O–Zr charge transfer transition, respectively. The charge transfer bands (CTB) of O{sup 2?}-Sm{sup 3+}, O{sup 2?}-Dy{sup 3+} and O{sup 2?}-Tm{sup 3+}, in Sm{sup 3+}, Dy{sup 3+} and Tm{sup 3+}-activated samples, have not been obviously observed probably because the 2p electrons of oxygen are tightly bound to the zirconium ion in the host lattice. For Eu{sup 3+}-activated samples, the relatively weak O{sup 2?}-Eu{sup 3+} CTB at about 220 nm is observed. And for Tb{sup 3+}-activated samples, the bands at 223 and 258 nm are related to the 4f-5d spin-allowed and spin-forbidden transitions of Tb{sup 3+}, respectively. It is observed that there is energy transfer between the host lattice and the luminescent activators (e.g. Eu{sup 3+}, Tb{sup 3+}). From the standpoint of luminescent efficiency, color purity and chemical stability, K{sub 2}GdZr(PO{sub 4}){sub 3}:Sm{sup 3+}, Eu{sup 3+}, Tb{sup 3+} are attractive candidates for novel yellow, red, green-emitting PDP phosphors.

  8. Anisotropy of the Irreversibility Field for Zr-doped (Y,Gd)Ba2<\\sub>Cu3<\\sub>O<7-x<\\sub> Thin Films up to 45 T

    SciTech Connect (OSTI)

    Tarantini, C. [Florida State University; Jaroszynski, J. [Florida State University; Kametani, F. [Florida State University; Zuev, Yuri L [ORNL; Gurevich, A. [Florida State University; Chen, Y [SuperPower Incorporated, Schenectady, New York; Selvamanickam, V. [SuperPower Incorporated, Schenectady, New York; Larbalestier, D. C. [Florida State University; Christen, David K [ORNL

    2011-01-01

    The anisotropic irreversibility fieldBIrr of twoYBa2Cu3O7 x thin films dopedwith additional rare earth (RE)= (Gd, Y) and Zr and containing strong correlated pins (splayed BaZrO3 nanorods and RE2O3 anoprecipitates) has been measured over a very broad range up to 45 T at temperatures 56 K < T < Tc. We found that the experimental angular dependence of BIrr ( ) does not follow the mass anisotropy scaling BIrr ( ) = BIrr (0)(cos2 + 2 sin2 ) 1/2, where = (mc/mab)1/2 = 5 6 for the RE-doped Ba2Cu3O7 x (REBCO) crystals, mab and mc are the effective masses along the ab plane and the c-axis, respectively, and is the angle between B and the c-axis. For B parallel to the ab planes and to the c-axis correlated pinning strongly enhances BIrr , while at intermediate angles, BIrr ( ) follows the scaling behavior BIrr ( ) (cos2 + 2 RP sin2 ) 1/2 with the effective anisotropy factor RP 3 significantly smaller than the ass anisotropy would suggest. In spite of the strong effects of c-axis BaZrO3 nanorods, we found even greater enhancements of BIrr for fields along the ab planes than for fields parallel to the c-axis, as well as different temperature dependences of the correlated pinning contributions to BIrr for B//ab and B//c. Our results show that the dense and strong pins, which can now be incorporated into REBCO thin films in a controlled way, exert major and diverse effects on the measured vortex pinning anisotropy and the irreversibility field over wide ranges of B and T . In particular, we show that the relative contribution of correlated pinning to BIrr for B//c increases as the temperature increases due to the suppression of thermal fluctuations of vortices by splayed distribution of BaZrO3 nanorods.

  9. Experimental study of neutron-rich nuclei near the N = 82 closed shell using the {sub 40}{sup 96}Zr+{sub 50}{sup 124}Sn reaction with GASP and PRISMA-CLARA arrays

    SciTech Connect (OSTI)

    Rodríguez, W.; Torres, D. A.; Cristancho, F.; Medina, N. H.; Chapman, R.; Smith, J. F.; Mengoni, D.; Truesdale, V.; Grocutt, L.; Mulholland, K.; Kumar, V.; Hadinia, B.; Labiche, M.; Liang, X.; O'Donell, D.; Ollier, J.; Orlandi, R.; Smith, J. F.; Spohr, K. M.; Wady, P.; and others

    2014-11-11

    In this contribution an experimental study of the deep-inelastic reaction {sub 40}{sup 96}Zr+{sub 50}{sup 124}Sn at 530 MeV, using the GASP and PRISMA-CLARA arrays, is presented. The experiments populate a wealth of projectile-like and target-like binary fragments, in a large neutron-rich region around N ? 50 and Z ? 40. Preliminary results on the study of the yrast and near-yrast states for {sup 95}Nb will be shown, along with a comparison of the experimental yields obtained in the experiments.

  10. Optical energy storage and reemission based weak localization of light and accompanying random lasing action in disordered Nd{sup 3+} doped (Pb, La)(Zr, Ti)O{sub 3} ceramics

    SciTech Connect (OSTI)

    Xu, Long; Zhao, Hua; Xu, Caixia; Zhang, Siqi; Zhang, Jingwen

    2014-08-14

    Multi-mode random lasing action and weak localization of light were evidenced and studied in normally transparent but disordered Nd{sup 3+} doped (Pb,La)(Zr,Ti)O{sub 3} ceramics. Noticeable localized zone and multi-photon process were observed under strong pumping power. A tentative phenomenological physical picture was proposed by taking account of diffusive process, photo-induced scattering, and optical energy storage process as dominant factors in elucidating the weak localization of light observed. Both the decreased transmittance (increased reflectivity) of light and the observed long lasting fading-off phenomenon supported the physical picture proposed by us.

  11. Rainfall Manipulation Plot Study (RaMPS)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Blair, John [Kansas State University; Fay, Phillip [USDA-ARS; Knapp, Alan [Colorado State University; Collins, Scott [University of New Mexico; Smith, Melinda [Yale University

    Data sets are available as ASCII files, in Excel spreadsheets, and in SAS format. (Taken from http://www.konza.ksu.edu/ramps/backgrnd.html

  12. Scientific Prospectus Site: 1043R-A

    E-Print Network [OSTI]

    to monitor pressure and to sample basement fluids. Drilling Program: Core with the RCB from 340 mbsf to total Water Depth: 4325 m Sediment Thickness: 420 mbsf Target Drilling Depth: 190 mbsf Approved Maximum Penetration: 470 mbsf; permission to drill without coring to 283 mbsf Seismic Coverage: Position of site

  13. OAS-RA-12-14

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i nAand DOEDepartmentNew2008Group, Inc. Order(National Renewable

  14. Microsoft Word - RA6120_2.doc

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformationJessework uses concrete7 Assessment ofLana Cox (803) TO:1 of 51Proposal

  15. Structure and magnetoresistance of a Ni{sub 79.7}Fe{sub 14.0}Co{sub 2.8}Zr{sub 2.0}Cu{sub 1.5} thin film

    SciTech Connect (OSTI)

    Varyukhin, V. N.; Izotov, A. I.; Moroz, T. T. Shkuratov, B. E.

    2013-01-15

    The structure and magnetoresistance R of thin films based on Ni{sub 80}Fe{sub 20} permalloy doped with Co, Zr, and Cu have been examined by X-ray diffraction analysis and resistance measurement. The films have been obtained by ion plasma sputtering on oxidized silicon, fused quartz, and glass ceramic cold substrates. It has been shown that the structure of a film in the initial state is a mixture of solid solutions based on two phases: Ni(fcc) particles with a size of L Almost-Equal-To 8 nm and (Zr{sub 0.67}Ni{sub 0.22}O{sub 0.11}){gamma} particles with a size of L Almost-Equal-To 12 nm. The R(H) dependences on the strength and direction of the magnetic field H have been obtained at room temperature for film samples in the initial state and after isothermal annealing at 653 K for 1 h. According to R(H) dependences and X-ray diffraction analysis, films in the initial state are assumingly in a superparamagnetic state, whereas they exhibit ferromagnetic properties after isothermal annealing.

  16. Distribution Behavior of U(VI), Pu(IV), Am(III), and Zr(IV) with N,N-Dihexyl Octanamide Under Uranium-Loading Conditions

    SciTech Connect (OSTI)

    Manchanda, V.K.; Ruikar, P.B.; Sriram, S.; Nagar, M.S.; Pathak, P.N.; Gupta, K.K.; Singh, R.K.; Chitnis, R.R.; Dhami, P.S.; Ramanujam, A. [Bhabha Atomic Research Centre (India)

    2001-06-15

    While the tri-n-butyl phosphate (TBP)-based PUREX process has been the workhorse of the nuclear fuel reprocessing industry for the last four and a half decades, a few drawbacks associated with the use of TBP have caused concern to the separation scientists and technologists. These shortcomings may pose a serious challenge particularly during the reprocessing of (a) short cooled thermal reactor fuels, (b) fast reactor fuels with the larger Pu content and significantly higher burn up, and (c) while treating various waste streams for their disposal to the environment. The N,N-dialkyl aliphatic amides have received particular attention as alternate potential extractants for the reprocessing of spent nuclear fuels in view of (a) the innocuous nature of their degradation products, namely, carboxylic acids/amines and (b) the possibility to incinerate the used solvent leading to reduced volume of secondary waste. The physical and chemical properties of these amides are influenced strongly by the nature of alkyl groups. The extractant N,N-dihexyl octanamide (DHOA) was found to be a promising candidate among a large number of extractants studied. Laboratory batch studies as well as mixer settler studies were performed under process conditions with DHOA and compared with those of TBP. DHOA was found to extract Pu(IV) more efficiently than TBP, both at trace-level concentration as well as under uranium loading conditions. In addition, the extraction behavior of Am(III) and Zr(IV) was studied at varying nitric acid concentrations (1 to 6 M). Extraction behavior of uranium at macroconcentrations (9.9 to 157.7 g/l) was carried out at different temperatures, and it was observed that D{sub U} decreased with the increase in U loading as well as with the increase of temperature (in the range 25 to 45 deg. C) and that the two-phase reaction was exothermic in nature. Mixer settler studies on U(VI) revealed that DHOA is similar to TBP during the extraction cycle but better than TBP during the stripping cycle.

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

    SciTech Connect (OSTI)

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

    2013-12-16

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

  18. Low-temperature evolution of local polarization properties of PbZr{sub 0.65}Ti{sub 0.35}O{sub 3} thin films probed by piezoresponse force microscopy

    SciTech Connect (OSTI)

    Andreeva, N. V.; Filimonov, A. V.; Rudskoy, A. I.; Tyunina, M.; Pertsev, N. A. Vakhrushev, S. B.

    2014-03-17

    The temperature evolution of local polarization properties in epitaxial PbZr{sub 0.65}Ti{sub 0.35}O{sub 3} films is studied by the low-temperature piezoresponse force microscopy (PFM). Pronounced changes in the film polarization state, including apparent polarization rotations and possible transitions between single-domain and polydomain states of individual ferroelectric nanocolumns, are revealed on cooling from the room temperature to 8?K using PFM imaging. More than two-fold increase in the coercive voltage extracted from the piezoresponse hysteresis loops is found on cooling from 240 to 8?K. The results are explained by the thermodynamic theory of strained epitaxial perovskite ferroelectric films.

  19. Calculations of the magnetic entropy change in amorphous through a microscopic anisotropic model: Applications to Dy{sub 70}Zr{sub 30} and DyCo{sub 3.4} alloys

    SciTech Connect (OSTI)

    Ranke, P. J. von Nóbrega, E. P.; Ribeiro, P. O.; Alvarenga, T. S. T.; Lopes, P. H. O.; Sousa, V. S. R. de; Oliveira, N. A. de; Caldas, A.; Alho, B. P.; Carvalho, G.; Magnus, A.

    2014-10-14

    We report theoretical investigations on the magnetocaloric effect, described by the magnetic entropy change in rare earth—transition metal amorphous systems. The model includes the local anisotropy on the rare earth ions in Harris-Plischke-Zuckermann assumptions. The transition metals ions are treated in terms of itinerant electron ferromagnetism and the magnetic moment of rare earth ions is coupled to the polarized d-band by a local exchange interaction. The magnetocaloric effect was calculated in DyCo{sub 3.4} system, which presents amorphous sperimagnetic configuration. The calculations predict higher refrigerant capacity in the amorphous DyCo{sub 3.4} than in DyCo{sub 2} crystal, highlighting the importance of amorphous magnetocaloric materials. Our calculation of the magnetocaloric effect in Dy{sub 70}Zr{sub 30}, which presents amorphous asperomagnetic configuration, is in good agreement with the experimental result. Furthermore, magnetic entropy changes associated with crystal-amorphous configurations change are estimated.

  20. Charge control of antiferromagnetism at PbZr{sub 0.52}Ti{sub 0.48}O{sub 3}/La{sub 0.67}Sr{sub 0.33}MnO{sub 3} interface

    SciTech Connect (OSTI)

    Ma, X.; Zhai, H.; Fang, F.; Lüpke, G., E-mail: gxluep@wm.edu [Department of Applied Science, College of William and Mary, 251 Jamestown Road, Williamsburg, Virginia 23187 (United States); Kumar, A. [Department of Physics and Institute for Functional Nanomaterials, University of Puerto Rico, San Juan, Puerto Rico 00931-3343 (United States); CSIR-National Physical Laboratory, New Delhi 110012 (India); Dussan, S.; Katiyar, R. S. [Department of Physics and Institute for Functional Nanomaterials, University of Puerto Rico, San Juan, Puerto Rico 00931-3343 (United States); Zhao, H. B. [Department of Optical Science and Engineering, Fudan University, 220 Handan Road, Shanghai 200433 (China); Scott, J. F. [Department of Physics and Institute for Functional Nanomaterials, University of Puerto Rico, San Juan, Puerto Rico 00931-3343 (United States); Department of Physics, Cavendish Laboratory, University of Cambridge, Cambridge CB3 OHE (United Kingdom)

    2014-03-31

    The interfacial spin state of the multiferroic heterostructure PbZr{sub 0.52}Ti{sub 0.48}O{sub 3}/La{sub 0.67}Sr{sub 0.33}MnO{sub 3} and its dependence on ferroelectric polarization is investigated with magnetic second-harmonic generation at 78?K. The spin alignment of Mn ions in the first unit cell layer at the heterointerface can be tuned from ferromagnetic to antiferromagnetic exchange coupled, while the bulk magnetization remains unchanged. Multiple domains of both phases coexist as the ferroelectric polarization is switched. The results will help promote the development of new interface-based functionalities and device concepts.

  1. Order parameter and scaling behavior in BaZr{sub x}Ti{sub 1?x}O{sub 3} (0.3 < x < 0.6) relaxor ferroelectrics

    SciTech Connect (OSTI)

    Usman, Muhammad; Mumtaz, Arif, E-mail: arif@qau.edu.pk; Raoof, Sobia; Hasanain, S. K. [Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan)] [Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan)

    2013-12-23

    We report the relaxor behavior of the zirconium doped barium titanate BaZr{sub x}Ti{sub 1?x}O{sub 3} solid solutions and discuss the temperature, frequency, and concentration dependence in terms of correlations among the polar nanoregions. The relaxor behavior is analyzed within the mean field theory by estimating the Edward-Anderson order parameter q{sub EA}. Additionally, we find that q{sub EA} calculated for the different concentrations obeys a scaling behavior q{sub EA}=1?(T/T{sub m}){sup n}, where T{sub m} are the respective dielectric maxima temperatures and n?=?2.0?±?0.1. The frequency dependence of the q{sub EA} also shows results consistent with the above mentioned picture.

  2. Carbon-Fluorine Bond Cleavage by Zirconium Metal Hydride Complexes

    E-Print Network [OSTI]

    Jones, William D.

    Carbon-Fluorine Bond Cleavage by Zirconium Metal Hydride Complexes Brian L. Edelbach, A. K. Fazlur, Rochester, New York 14627 Received April 8, 1999 The zirconium hydride dimer [Cp2ZrH2]2 reacts with C6F6. [Cp2ZrH2]2 reacts with C6F5H to give Cp2Zr(p-C6F4H)F, Cp2ZrF2, C6F4H2, and H2. The zirconium hydride

  3. Photoluminescence in Pb{sub 0.95}Sr{sub 0.05}(Zr{sub 1?x}Ti{sub x}){sub 1?y}Cr{sub y}O{sub 3} ferroelectric ceramic system

    SciTech Connect (OSTI)

    Hernández-García, M.; Costa-Marrero, J.; Durruthy-Rodríguez, M. D.; Calderón-Piñar, F.; Guerra, J. D. S.; Yañez-Limón, J. M.

    2014-07-28

    Over the past several years, there has been a remarkable growth and development in new ceramic and/or composite materials to be used in the electro-electronic industry. Ferroelectric materials have been recognized for their multifunctional physical properties; also, their optical properties are a subject of intense research effort due to their possible electro-optic applications. In this work, the visible photoluminescence effect is analyzed at room temperature in a sintered Pb{sub 0.95}Sr{sub 0.05}(Zr{sub 1?x}Ti{sub x}){sub 1?y}Cr{sub y}O{sub 3} perovskite-type structure system, doped with Sr and Cr. The excitation bands used were 267, 325, 373, 457, 635, and 680?nm, but the best result was obtained at 373?nm. The intensity and energy of such emission in this system have been studied by changing the molar Cr concentration (0?Zr or Ti ions in the symmetry presented in the rhombohedral or tetragonal side of the MPB are more important. Additionally, structural and micro-structural measurements were performed by the x-ray diffraction and scanning electron microscopy techniques, respectively. The micro-Raman technique is also used in the study of this set of samples, which allows finding the Raman shift modes and the influence on the structural changes of the dopants.

  4. (RA) Josef's Cost Centers (RA) Jena's Cost Centers BK Anesthesiology LN Biomedical Engineering

    E-Print Network [OSTI]

    Portman, Douglas

    Development & Disease AC Center for Oral Biology LN Center for Primary Care AB Center for Pediatric Biomedical Pharmacology & Physiology AB Pediatrics BK Physical Medicine & Rehabilitation JC Public Health Sciences DB (General) CW School of Medicine and Dentistry - Dean's office LN Surgery (Vascular) AC School of Nursing

  5. Temperature driven nano-domain evolution in lead-free Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}-50(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} piezoceramics

    SciTech Connect (OSTI)

    Lu, Shengbo Xu, Zhengkui; Su, Shi; Zuo, Ruzhong

    2014-07-21

    Hierarchical micro- and nanoscale domain structures in Pb-free Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}-50(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} piezoceramics were investigated by transmission electron microscopy. In situ heating and cooling studies of domain structure evolution reveal an irreversible domain transformation from a wedge-shaped rhombohedral nanodomain structure to a lamellar tetragonal domain structure, which could be associated with strong piezoelectricity in Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}-50(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} piezoceramics.

  6. Ceramic plasma-sprayed coating of melting crucibles for casting metal fuel slugs

    SciTech Connect (OSTI)

    K.H. Kim; C.T. Lee; C.B. Lee; R.S. Fielding; J.R. Kennedy

    2013-10-01

    Thermal cycling and melt reaction studies of ceramic coatings plasma-sprayed on Nb substrates were carried out to evaluate the performance of barrier coatings for metallic fuel casting applications. Thermal cycling tests of the ceramic plasma-sprayed coatings to 1450 degrees C showed that HfN, TiC, ZrC, and Y2O3 coating had good cycling characteristics with few interconnected cracks even after 20 cycles. Interaction studies by 1550 degrees C melt dipping tests of the plasma-sprayed coatings also indicated that HfN and Y2O3 do not form significant reaction layer between U–20 wt.% Zr melt and the coating layer. Plasma-sprayed Y2O3 coating exhibited the most promising characteristics among HfN, TiC, ZrC, and Y2O3 coating.

  7. A new Bi{sub 0.5}Na{sub 0.5}TiO{sub 3} based lead-free piezoelectric system with calculated end-member Bi(Zn{sub 0.5}Hf{sub 0.5})O{sub 3}

    SciTech Connect (OSTI)

    Liu, Feng; Wahyudi, Olivia; Li, Yongxiang

    2014-03-21

    The phase structure, dielectric and piezoelectric properties of a new lead-free piezoelectric system (1???x)Bi{sub 0.5}Na{sub 0.5}TiO{sub 3}–xBi(Zn{sub 0.5}Hf{sub 0.5})O{sub 3} [(1???x)BNT–xBZH, x?=?0, 0.01, 0.02, 0.03, and 0.04] were investigated. The structure of Bi(Zn{sub 0.5}Hf{sub 0.5})O{sub 3} was calculated using first-principles method and (1???x)BNT–xBZH ceramics were fabricated by conventional solid-state process. At room temperature, a morphotropic phase boundary (MPB) from rhombohedral to pseudocubic is identified near x?=?0.02 by the analysis of X-ray diffraction patterns. The ceramics with MPB near room temperature exhibit excellent electrical properties: the Curie temperature, maximum polarization, remnant polarization, and coercive field are 340?°C, 56.3??C/cm{sup 2}, 43.5??C/cm{sup 2}, and 5.4?kV/mm, respectively, while the maximum positive bipolar strain and piezoelectric coefficient are 0.09% and 92 pC/N, respectively. In addition, a linear relationship between the MPB phase boundary composition and the calculated tetragonality of non-BNT end-member was demonstrated. Thus, this study not only shows a new BNT-based lead-free piezoelectric system but also suggest a new way to predict the composition at MPB a priori when designing new lead-free piezoelectric system.

  8. Phase evolution studies in CaZrTi{sub 2}O{sub 7}?RE{sub 2}Ti{sub 2}O{sub 7} (RE?=?Nd{sup 3+}, Sm{sup 3+}) system: Futuristic ceramic host matrices for nuclear waste immobilization

    SciTech Connect (OSTI)

    Jafar, M. Achary, S. N. Tyagi, A. K.

    2014-04-24

    Series of compositions with general stoichiometry as Ca{sub 1?x}Zr{sub 1?x}RE{sub 2x}Ti{sub 2}O{sub 7} (RE?=?Nd{sup 3+}, Sm{sup 3+}) were prepared by solid state reaction and characterized by powder x-ray diffraction technique to unravel the phase fields in the title systems. The phase fields in CaZrTi{sub 2}O{sub 7?}Nd{sub 2}Ti{sub 2}O{sub 7} and CaZrTi{sub 2}O{sub 7?}Sm{sub 2}Ti{sub 2}O{sub 7} systems differed significantly at the rareearth rich regions. The common phase fields like zirconolite-2M, zirconolite-4M, cubic perovskite are observed at the zirconolite rich regions of both systems. Depending on the structure of RE{sub 2}Ti{sub 2}O{sub 7} phase, the cubic pyrochlore or monoclinic RE{sub 2}Ti{sub 2}O{sub 7} phases are observed in the studied system. The observed phase fields in these two systems indicate ionic radius of the rare-earth ion has a dominating role in the phase relations. Further details of the phases and their homogeneity are explained in the text of the manuscript.

  9. Structure and ferroelectric studies of (Ba{sub 0.85}Ca{sub 0.15})(Ti{sub 0.9}Zr{sub 0.1})O{sub 3} piezoelectric ceramics

    SciTech Connect (OSTI)

    Venkata Ramana, E.; Mahajan, A.; Graça, M.P.F.; Mendiratta, S.K.; Monteiro, J.M.; Valente, M.A.

    2013-10-15

    Graphical abstract: - Highlights: • (Ba{sub 0.85}Ca{sub 0.15})(Ti{sub 0.9}Zr{sub 0.1})O{sub 3} (BCTZO) ceramic was synthesized by the ceramic method. • In situ XRD and Raman spectra showed the phase transition of BCTZO around 360 K. • The ceramics showed a tunability of 82% at 40 kV cm{sup ?1} electric field. • BCTZO exhibited good quality factor of 111 at microwave frequencies. • Piezoforce microscopy studies indicated the switchability of ferroelectric domains. - Abstract: We have synthesized and studied the structural and ferroelectric properties of lead-free 0.5(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3}–0.5Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3} ceramics in the temperature region of its ferroelectric transition. The synthesized material showed high dielectric constant, low loss and good pyroelectric figure of merit. From the temperature dependent X-ray diffraction measurements, we determined the tricritical point to be in the temperature range of 303–400 K. The dielectric measurements indicate a diffuse ferroelectric phase transition (DPT) around 360 K in agreement with the X-ray measurements. We studied the evolution of Raman spectra with temperature to understand the nature of phase transition in BaTiO{sub 3} (BTO) and the BCTZO. The results indicates that the transition of ferroelectric–paraelectric state is not sharp as in the case of BTO and the polar state persists through the paraelectric state. In general, our study indicates that there are ferroelectric domains of nanometer size beyond the commonly defined transition temperature. The observation of local piezoelectric hysteresis loop indicated the existence of intrinsic ferroelectric property of the ceramic at the nanoscale. The ceramics exhibited electric field tunable dielectric properties with a tunability of 82% at an applied DC field of 40 kV cm{sup ?1}, low dielectric loss of 0.001 and room temperature pyroelectric coefficient of 6 × 10{sup ?8} C cm{sup ?2} K{sup ?1} and the detectivity of 1.9 × 10{sup ?8} C cm{sup ?1} J{sup ?1}; larger than those reported for other BaTiO{sub 3}-based materials. Overall, our results indicate that BCTZO ceramics with coexistence of rhombohedral–tetragonal phases is a promising candidate for lead-free ferroelectric applications.

  10. JOURNAL DE PHYSIQUE Colloque C8, Supplement au no 12, Tome 49, dhcembre 1988

    E-Print Network [OSTI]

    Boyer, Edmond

    in SCCO~, YCo2 and LuCO~is very different from those in TiCo2, ZrCo2 and HfCoa. Thus, the A atom seems. The shapes of the DOS and the positions of EF for ScCo2, YCOZand LuCo2 are very similar to each other. For TiCo2, ZrCo2 and HfCo2, they are also very similar to each other but different from those for SCCO~,YCo2

  11. Diffused phase transitions in Pb(Zr{sub 0.65}Ti{sub 0.35})O{sub 3}-Pb(Fe{sub 2/3}W{sub 1/3})O{sub 3} multiferroics

    SciTech Connect (OSTI)

    Tirupathi, Patri; Kumar, Nawnit; Pastor, Mukul Pandey, A. C.; Choudhary, R. N. P.

    2015-02-21

    The solid solutions of (1?x)Pb(Zr{sub 0.65}Ti{sub 0.35})O{sub 3}-xPb(Fe{sub 2/3}W{sub 1/3})O{sub 3} in different ratios were fabricated by a high-temperature solid-state reaction method using high-purity oxides for possible multi-ferroic applications. Structural analysis using x-ray diffraction powder patterns of the system by Rietveld refinement method exhibits the formation of rhombohedral phase with R3c space group. Detailed studies of dielectric permittivity as a function of temperature of the systems show that the frequency independent dielectric maximum temperature shifts toward room temperature on increasing x. In addition to this, the degree of diffuseness of the permittivity anomaly is more pronounced for higher content of Pb(Fe{sub 2/3}W{sub 1/3})O{sub 3}, implying the existence of a composition-induced diffuse phase transition for the limited range of compositional ratios. Detailed impedance spectroscopy analysis shows the contributions of grain, grain boundary, and interfacial polarizations in the resistive characteristics and conduction mechanism of the materials. The weak ferromagnetic and saturated ferroelectric loops indicate that system with x?=?0.1, 0.2 have good multiferroic characteristics, and may be useful for future spintronic devices.

  12. Softening of antiferroelectricity in PbZrO{sub 3}-Pb(Mn{sub 1/2}W{sub 1/2})O{sub 3} complex perovskite solid solution

    SciTech Connect (OSTI)

    Ren, Zihe; Zhang, Nan; Su, Lun-Wei; Wu, Hua; Ye, Zuo-Guang

    2014-07-14

    A new solid solution of complex perovksite structure, (1-x)PbZrO{sub 3}-xPb(Mn{sub 1/2}W{sub 1/2})O{sub 3} (PZ-xPMnW, with x?=?0–0.1), is prepared by solid state reaction method. Its crystal structure, dielectric properties, and antiferroelectricity are investigated. It is found that the crystal structure of the solid solution remains in the orthorhombic Pbam symmetry with x???0.1. The induced ferroelectric polarization (P{sub Ind}) is enhanced, whereas the critical field (E{sub Cr}) is decreased, with increasing PMnW concentration, indicating the softening of antiferroelectricity in PZ. The Curie temperature (T{sub C}) is also decreased with the substitution of PMnW for PZ. The grain size is significantly enlarged, which could be attributed to the presence of a transient liquid phase during the sintering process. Measurements of the magnetization by means of SQUID confirm that the Mn ion exists in a high spin state with a 2+ oxidation state. The softening of antiferroelectric order and the improvement in induced polarization make the PZ-PMnW ceramics an interesting material system for such applications as energy storage devices.

  13. Low-frequency inelastic light scattering in a ZBLAN (ZrF{sub 4}-BaF{sub 2}-LaF{sub 3}-AlF{sub 3}-NaF) glass

    SciTech Connect (OSTI)

    Adichtchev, S. V.; Malinovsky, V. K.; Surovtsev, N. V., E-mail: lab21@iae.nsk.su [Institute of Automation and Electrometry, Siberian Branch of Russian Academy of Sciences, Novosibirsk 630090 (Russian Federation); Ignatieva, L. N.; Merkulov, E. B. [Institute of Chemistry, Far East Branch of Russian Academy of Sciences, Vladivostok 690022 (Russian Federation)] [Institute of Chemistry, Far East Branch of Russian Academy of Sciences, Vladivostok 690022 (Russian Federation)

    2014-05-14

    Low-frequency (down to 30 GHz) inelastic light scattering is studied in a multicomponent glass ZBLAN (ZrF{sub 4}-BaF{sub 2}-LaF{sub 3}-AlF{sub 3}-NaF) in a wide temperature range. The contributions of the THz vibrational spectrum (boson peak) and of the fast relaxation are extracted and analyzed. It is shown that the fast relaxation spectrum is described by a distribution of relaxation times leading to a power-law ?{sup ?} dependence in the frequency range 30–300 GHz. Temperature dependence of ?(T) is well described by the Gilroy-Phillips model, while the integrated intensity of the fast relaxation increases significantly with the temperature. This feature distinguishes the fast relaxation in ZBLAN from the case of most single-component glasses. Thermodynamic and kinetic fragility indexes are significantly different for the ZBLAN glass. The correlations between the boson peak intensity, elastic moduli, and fragility index, found earlier for single-component glasses, are fulfilled for the thermodynamic fragility index of ZBLAN. In contrast, the correlation between the fast relaxation intensity at T{sub g} and the fragility holds better for the kinetic fragility index of ZBLAN. We propose that thermodynamic and kinetic fragilities reflect different aspects of glassy dynamics in the case of glass formers with the complex chemical composition and structure topology: the former correlates with the elastic properties and the boson peak, the latter with the relaxation.

  14. ZIRCONIUM—HAFNIUM ISOTOPE EVIDENCE FROM METEORITES FOR THE DECOUPLED SYNTHESIS OF LIGHT AND HEAVY NEUTRON-RICH NUCLEI

    SciTech Connect (OSTI)

    Akram, W.; Schönbächler, M.; Sprung, P.; Vogel, N.

    2013-11-10

    Recent work based on analyses of meteorite and terrestrial whole-rock samples showed that the r- and s- process isotopes of Hf were homogeneously distributed throughout the inner solar system. We report new Hf isotope data for Calcium-Aluminum-rich inclusions (CAIs) of the CV3 carbonaceous chondrite Allende, and novel high-precision Zr isotope data for these CAIs and three carbonaceous chondrites (CM, CO, CK). Our Zr data reveal enrichments in the neutron-rich isotope {sup 96}Zr (?1? in {sup 96}Zr/{sup 90}Zr) for bulk chondrites and CAIs (?2?). Potential isotope effects due to incomplete sample dissolution, galactic and cosmic ray spallation, and the nuclear field shift are assessed and excluded, leading to the conclusion that the {sup 96}Zr isotope variations are of nucleosynthetic origin. The {sup 96}Zr enrichments are coupled with {sup 50}Ti excesses suggesting that both nuclides were produced in the same astrophysical environment. The same CAIs also exhibit deficits in r-process Hf isotopes, which provides strong evidence for a decoupling between the nucleosynthetic processes that produce the light (A ? 130) and heavy (A > 130) neutron-rich isotopes. We propose that the light neutron-capture isotopes largely formed in Type II supernovae (SNeII) with higher mass progenitors than the supernovae that produced the heavy r-process isotopes. In the context of our model, the light isotopes (e.g. {sup 96}Zr) are predominantly synthesized via charged-particle reactions in a high entropy wind environment, in which Hf isotopes are not produced. Collectively, our data indicates that CAIs sampled an excess of materials produced in a normal mass (12-25 M{sub ?}) SNII.

  15. Gamow-Teller Strength distributions in $^{76}\\textrm{Ge}$, $^{76,82}\\textrm{Se}$, and $^{90,92}\\textrm{Zr}$ by the Deformed Proton-neutron QRPA

    E-Print Network [OSTI]

    Eunja Ha; Myung-Ki Cheoun

    2014-09-06

    We developed the deformed proton-neutron quasiparticle random phase approximation (QRPA) and applied to the evaluation of the Gamow-Teller (GT) transition strength distributions including high-lying excited states, which data becomes recently available beyond one or two nucleon threshold by charge exchange reactions using hundreds of MeV projectiles. Our calculations started with single-particle states calculated by a deformed axially symmetric Woods-Saxon potential. Neutron-neutron and proton-proton pairing correlations are explicitly taken into account at the deformed Bardeen Cooper Schriffer theory. Ground state correlations, and two-particle and two-hole mixing states are included in the deformed QRPA. In this work, we use a realistic two-body interaction given by the Brueckner $G$-matrix based on the CD Bonn potential to reduce the ambiguity on the nucleon-nucleon interactions inside nuclei. We applied our formalism to the GT transition strengths for $^{76}$Ge, $^{76,82}$Se, and $^{90,92}\\textrm{Zr}$, and compared to available experimental data. The GT strength distributions were sensitive on the deformation parameter as well as its sign, {\\it i.e.}, oblate or prolate. The Ikeda sum rule, which is usually thought to be satisfied under the one-body current approximation irrespective of nucleon models, is used to test our numerical calculations and shown to be satisfied without introducing the quenching factor, if high-lying GT excited states are properly taken into account. Most of the GT strength distributions of the nuclei considered in this work turn out to have the high-lying GT excited states beyond one nucleon threshold, which are shown to be consistent with available experimental data.

  16. Microstructural Evolution of 7 wt.% Y2O3 ZrO2 Thermal Barrier Coatings due to Stress Relaxation at Elevated Temperatures and the Concomitant changes in Thermal Conductivity

    SciTech Connect (OSTI)

    Petorak, Christopher [Purdue University; Ilavsky, Dr. Jan [Argonne National Laboratory (ANL); Wang, Hsin [ORNL; Porter, Wallace D [ORNL; Trice, Rodney [Purdue University

    2010-01-01

    The purpose of this study was to evaluate the combined effect of stress and temperature on the microstructure of air plasma-sprayed 7 wt.% Y{sub 2}O{sub 3}-ZrO{sub 2} thermal barrier coatings, and relate microstructural changes to the thermal conductivity, k{sub th}. To simulate TBC service conditions, stand-alone tubes of YSZ were stress relaxed, starting from a compressive stress of 60 MPa, at temperatures of 1000 C or 1200 C. The duration of the stress relaxation test was either 5 min or 3 h. Detailed scanning electron microscopy (SEM) and Porod's specific surface area (SSA) analysis of small angle neutron scattering (SANS) results were used to determine which void systems, either interlamellar pores or intralamellar cracks, contributed to the observed relaxation of stress in the coatings. SEM investigations revealed closure of intralamellar cracks located perpendicular to the stress direction. For thinner YSZ coatings, SANS measurements indicated a statistically significant reduction in the total SSA and SSA associated with intralamellar cracks after stress relaxation at the times, temperatures, and stress investigated compared to those samples that were exposed to identical times and temperatures, but no stress. The SSA associated with the interlamellar pores was not significantly smaller in YSZ coatings stress relaxed from 60 MPa at 1200 C for 3 h compared to as-sprayed coatings. The thermal conductivity of the coatings was strongly influenced by stress, with increases in kth observed after only 5 min at 60 MPa and 1200 C. Reductions in the total SSA were directly linked to increases in k{sub th}.

  17. The effect of Cu/Zn molar ratio on CO{sub 2} hydrogenation over Cu/ZnO/ZrO{sub 2}/Al{sub 2}O{sub 3} catalyst

    SciTech Connect (OSTI)

    Shaharun, Salina, E-mail: salinashaharun@gmail.com, E-mail: maizats@petronas.com.my; Shaharun, Maizatul S., E-mail: salinashaharun@gmail.com, E-mail: maizats@petronas.com.my; Taha, Mohd F., E-mail: faisalt@petronas.com.my [Department of Fundamental and Applied Science, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak (Malaysia); Mohamad, Dasmawati, E-mail: dasmawati@kck.usm.my [School of Dental Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia)

    2014-10-24

    Catalytic hydrogenation of carbon dioxide (CO{sub 2}) to methanol is an attractive way to recycle and utilize CO{sub 2}. A series of Cu/ZnO/Al{sub 2}O{sub 3}/ZrO{sub 2} catalysts (CZAZ) containing different molar ratios of Cu/Zn were prepared by the co-precipitation method and investigated in a stirred slurry autoclave system. The catalysts were characterized by temperature-programmed reduction (TPR), field emission scanning electron microscopy-energy dispersive analysis (FESEM-EDX), X-ray diffraction (XRD) and N{sub 2} adsorption-desorption. Higher surface area, SA{sub BET} values (42.6–59.9 m{sup 2}/g) are recorded at low (1) and high (5) Cu/Zn ratios with the minimum value of 35.71 m{sup 2}/g found for a Cu/Zn of 3. The reducibility of the metal oxides formed after calcination of catalyst samples was also affected due to change in metal-support interaction. At a low reaction temperature of 443 K, total gas pressure of 3.0 MPa and 0.1 g/mL of the CZAZ catalyst, the selectivity to methanol decreased as the Cu/Zn molar ratio increased, and the maximum selectivity of 67.73 was achieved at Cu/Zn molar ratio of 1. With a reaction time of 3h, the best performing catalyst was CZAZ75 with Cu/Zn molar ratio of 5 giving methanol yield of 79.30%.

  18. TU-F-12A-01: Quantitative Non-Linear Compartment Modeling of 89Zr- and 124I- Labeled J591 Monoclonal Antibody Kinetics Using Serial Non-Invasive Positron Emission Tomography Imaging in a Pre-Clinical Human Prostate Cancer Mouse Model

    SciTech Connect (OSTI)

    Fung, EK; Cheal, SM; Chalasani, S; Fareedy, SB; Punzalan, B; Humm, JL; Osborne, JR; Larson, SM; Zanzonico, PB; Otto, B; Bander, NH

    2014-06-15

    Purpose: To examine the binding kinetics of human IgG monoclonal antibody J591 which targets prostate-specific membrane antigen (PSMA) in a pre-clinical mouse cancer model using quantitative PET compartmental analysis of two radiolabeled variants. Methods: PSMA is expressed in normal human prostate, and becomes highly upregulated in prostate cancer, making it a promising therapeutic target. Two forms of J591, radiolabeled with either {sup 89}Zr or {sup 124}I, were prepared. {sup 89}Zr is a radiometal that becomes trapped in the cell upon internalization by the antigen-antibody complex, while radioiodine leaves the cell. Mice with prostate cancer xenografts underwent non-invasive serial imaging on a Focus 120 microPET up to 144 hours post-injection of J591. A non-linear compartmental model describing the binding and internalization of antibody in tumor xenograft was developed and applied to the PET-derived time-activity curves. The antibody-antigen association rate constant (ka), total amount of antigen per gram tumor (Ag-total), internalization rate of antibody-antigen complex, and efflux rate of radioisotope from tumor were fitted using the model. The surface-bound and the internalized activity were also estimated. Results: Values for ka, Ag-total, and internalization rate were found to be similar regardless of radiolabel payload used. The efflux rate, however, was ? 9-fold higher for {sup 124}I-J591 than for {sup 89}Zr-J591. Time-dependent surface-bound and internalized radiotracer activity were similar for both radiolabels at early times post-injection, but clearly differed beyond 24 hours. Conclusion: Binding and internalization of J591 to PSMA-expressing tumor xenografts were similar when radiolabeled with either {sup 89}Zr or {sup 124}I payload. The difference in efflux of radioactivity from tumor may be attributable to differential biological fate intracellularly of the radioisotopes. This has great significance for radioimmunotherapy and antibody-drug conjugates. Further exploration using the model will examine binding and radioisotope residence as antibody dose is increased to antigen saturation. The Center for Targeted Radioimmunotherapy and Theranostics, Ludwig Center for Cancer Immunotherapy, Memorial Sloan Kettering Cancer Center (MSK), NIH (R25-CA096945). Technical services provided by the MSK Small-Animal Imaging Core Facility were supported by the NIH (R24-CA83084, P30-CA08748, and P50-CA92629; Zanzonico). NCI, Center to Reduce Cancer Health Disparity (R21 CA153177-03; Osborne)

  19. Buffer architecture for biaxially textured structures and method of fabricating same

    DOE Patents [OSTI]

    Norton, David P.; Park, Chan; Goyal, Amit

    2004-04-06

    The invention relates to an article with an improved buffer layer architecture comprising a substrate having a metal surface, and an epitaxial buffer layer on the surface of the substrate. The epitaxial buffer layer comprises at least one of the group consisting of ZrO.sub.2, HfO.sub.2, and compounds having at least one of Ca and a rare earth element stabilizing cubic phases of ZrO.sub.2 and/or HfO.sub.2. The article can also include a superconducting layer deposited on the epitaxial buffer layer. The article can also include an epitaxial capping layer between the epitaxial buffer layer and the superconducting layer. A method for preparing an epitaxial article comprises providing a substrate with a metal surface, depositing on the metal surface an epitaxial buffer layer comprising at least one material selected from the group consisting of ZrO.sub.2, HfO.sub.2, and compounds having at least one of Ca and a rare earth element stabilizing cubic phases of at least one of ZrO.sub.2 and HfO.sub.2. The epitaxial layer depositing step occurs in a vacuum with a background pressure of no more than 1.times.10.sup.-5 Torr. The method can further comprise depositing a superconducting layer on the epitaxial layer, and depositing an epitaxial capping layer between the epitaxial buffer layer and the superconducting layer.

  20. Advanced Materials for Fusion S.J. Zinkle1 and A. Kohyama2

    E-Print Network [OSTI]

    · Ferritic/Martensitic Steels - low temperature radiation hardening - Thermal creep limits - possible He of Improved Materials ­Advanced steels, including Nanocomposited ferritic steel ­Refractory alloys (V, Mo, WC/SiC CuNiBe 316 SS F/M steel ODS ferritic st. V-4Cr-4Ti Nb-1Zr-.1C Ta-8W-2Hf Mo (TZM) W Temperature (°C

  1. Polyorganometallosiloxane-2- or -4-pyridine coatings

    DOE Patents [OSTI]

    Sugama, Toshifumi (Wading River, NY)

    1997-01-01

    A new family of polyorganometallosiloxane-2- or -4-pyridine compounds are provided for corrosion resistant coatings on light metals such as aluminum, magnesium, zinc, steel and their allows. The novel compounds contain backbones modified by metal alkoxides, metallocenes and metallophthalocyanates where the metal is Zr, Ti, Mo, V, Hf, Nb, Si, B and combinations thereof. Methods of making the new compounds are also provided.

  2. Nanocrystals Embedded Zirconium-doped Hafnium Oxide High-k Gate Dielectric Films 

    E-Print Network [OSTI]

    Lin, Chen-Han

    2012-10-19

    nanoparticles. These results can be important to the novel metal gate/high-k/Si MOS structure. The Ru-modified ZrHfO gate dielectric film showed a large breakdown voltage and a long lifetime. The conventional polycrystalline Si (poly-Si) charge trapping layer...

  3. Long range ordered alloys modified by addition of niobium and cerium

    DOE Patents [OSTI]

    Liu, C.T.

    1984-08-22

    Long range ordered alloys are described having the nominal composition (Fe,Ni,Co)/sub 3/ (V,M) where M is a ductility enhancing metal selected from the group Ti, Zr, Hf with additions of small amounts of cerium and niobium to dramatically enhance the creep properties of the resulting alloys.

  4. Synthesis, Characterization, and Activation of Zirconium and Hafnium Dialkyl Complexes that Contain a

    E-Print Network [OSTI]

    Müller, Peter

    Synthesis, Characterization, and Activation of Zirconium and Hafnium Dialkyl Complexes that Contain of zirconium and hafnium complexes, [MepyN]MX2 (M ) Zr, X ) NMe2, Cl, OSO2CF3, CH2CHMe2, CH2Ph; M ) Hf, X ) NMe

  5. J. Am. Chem. SOC. retention of unsaturated tin in the product is precluded either by

    E-Print Network [OSTI]

    Girolami, Gregory S.

    for metal cutting tools,, as crucibles and electrodes in metal-refining equipment such as aluminum reduction of group 4 diborides, MB, (where M = Ti, Zr, Hf), as coatings prepared by chemical vapor deposition (CVD at high temperature and make the diborides, particularly TiB,, useful for such applications as coatings

  6. Microsoft Word - Zr-ORNL-final-IV

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

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

  7. Temperature dependent Raman scattering and far-infrared reflectance spectra of MgO modified Pb{sub 0.99}(Zr{sub 0.95}Ti{sub 0.05}){sub 0.98}Nb{sub 0.02}O{sub 3} ceramics: A composition effect

    SciTech Connect (OSTI)

    Duan, Z. H.; Chang, P.; Hu, Z. G. Chu, J. H.; Wang, J. X.; Wang, G. S.; Dong, X. L.

    2014-09-07

    Lattice dynamics and phase transition of MgO modified Pb{sub 0.99}(Zr{sub 0.95}Ti{sub 0.05}){sub 0.98}Nb{sub 0.02}O{sub 3} (PZTN-x wt. % MgO, x?=?0, 0.1, 0.2, 0.5) ceramics have been investigated by far-infrared (FIR) reflectance in the temperature range of 5.5–300?K and Raman spectra between 77 and 300?K, respectively. With the aid of above complementary methods, the structure of all ceramics was defined as low-temperature ferroelectric rhombohedral phase [F{sub R(LT)}] at room temperature. The FIR dielectric functions were extracted from the multi-Lorentz oscillator dispersion model. The lowest frequency phonon mode, which is related to Pb-BO{sub 3} (B?=?Zr, Ti, Nb) vibration, mainly dominates the FIR dielectric response. With increasing MgO composition, the dielectric constants ?(0) at room temperature are estimated to 85.4, 73.4, 73.9, and 41.9, respectively. The decreasing trend can be due to the doubly ionized oxygen vacancies induced by Mg substitution for B-site. The order-disorder phase transition located around 120?K can be clearly clarified from temperature evolution of phonon frequency, damping, and intensity. It decreases slightly with increasing MgO composition, which influence the distortion due to the broken correlation chains and local permanent dipoles creation. Moreover, the transformation from antiferroelectric orthorhombic A{sub O} to [ F{sub R(LT)} ] phase has been observed around 250?K, which is associated with the antiferroelectric displacement of Pb atoms along ? 110 ? and coupled rotations of the corner-connected oxygen octahedral. Furthermore, the transition from [ F{sub R(LT)} ] to [ F{sub R(HT)} ] (high-temperature ferroelectric rhombohedral phase) was identified around 290?K for MgO-doped PZTN ceramics. It arises from the shift of cation (Pb and Zr/Ti/Nb/Mg ions) along the ? 111 ? direction and the transition temperature slightly decreases compared to the pure ceramic.

  8. Powering the Advancement of Science eRA Commons

    E-Print Network [OSTI]

    ................................................................................................................. 3 2 Delegating Authority............................................................................................................................ 1 2.1 Overview.......................................................................................................................... 1 2.2 SO--Delegating Submit Authority

  9. w, R.M., Ra enzullo, L., V

    E-Print Network [OSTI]

    Phipps, Steven J.

    mmunity ge (CAB aupach, M.R Van Dijk, A. hnical Repo entre for Aus nership betwe y Atmos BLE) m R, 2 ., Pitman, A.J3 ., Renzullo, L5 ., Van Dijk, A5, 6 . and Wang, Y-P1, 2 . 1 The Centre, M.R., Abramowitz, G., Dharssi, I., Haverd, V., Pitman, A.J., Renzullo, L., Van Dijk, A. and Wang, Y

  10. NASA's Earth Observing System CloudsandtheEarth'sRa

    E-Print Network [OSTI]

    of Gary G. Gibson, Head of the Radiation and Aerosols Branch, and Bruce A. Wielicki, CERES for improving our scientific understanding of ongoing natural and human-induced global climate change's Radiant Energy System (CERES) experiment is one of the highest priority sci- entific satellite instruments

  11. Luciana Puntillo Diamante Advisor: Dr. Behrooz Shirazi RA: Nina Peterson

    E-Print Network [OSTI]

    Collins, Gary S.

    Parthasarathy for her help. REFERENCES 1. United States Geological Survey web page http of EECS, Washington State University, Pullman This work was supported by the National Science Foundation of deaths (more than 29,000)[2]. An example of that is Mt. Saint Helens, WA; and its eruption on May1980

  12. The Athlit ra: Classical and Hellenistic bronze casting 

    E-Print Network [OSTI]

    Oron, Asaf

    2001-01-01

    existing rams in size and is one of the largest bronzes to have survived intact from the ancient Mediterranean world. Initial metallographic and metallurgical analyses of the ram, made shortly after its recovery, led to the conclusion that it was cast...

  13. Handcrafting in the Nanoworld Reading Assignment 1 (RA1)

    E-Print Network [OSTI]

    Falvo, Michael

    sequences of DNA, we can also make predetermined sequences of amino acids, the building blocks of proteins teaspoon of oil onto the surface of a small lake and found that it spread out .... Well, I'll let him to be one Day very rough with the Wind, I fetched out a Cruet of Oil, and dropt a little of it on the Water

  14. The Advanced Research Projects, OAS-RA-11-11

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankADVANCEDInstallers/ContractorsPhotovoltaics »TanklessResearchEnergy2 DOE Hydrogen12The AdAudit

  15. The A-site driven phase transition procedure of (Pb{sub 0.97}La{sub 0.02})(Zr{sub 0.42}Sn{sub 0.40}Ti{sub 0.18})O{sub 3} ceramics: An evidence from electronic structure variation

    SciTech Connect (OSTI)

    Chen, X.; Jiang, P. P; Duan, Z. H.; Hu, Z. G. Chu, J. H.; Chen, X. F.; Wang, G. S.; Dong, X. L.

    2013-11-04

    The transition of (Pb{sub 0.97}La{sub 0.02})(Zr{sub 0.42}Sn{sub 0.40}Ti{sub 0.18})O{sub 3} (PLZST) ceramic has been investigated by temperature-dependent X-ray diffraction (XRD) and spectroscopic ellipsometry (SE). The rhombohedral and tetragonal symmetries are confirmed by XRD analysis. Two interband transitions (E{sub cp1} and E{sub cp2}) located at about 3.7 and 5.2?eV can be derived from the second derivative of the complex dielectric functions using the standard critical point (SCP) model. Except for the negative temperature coefficient parts, the transitions present additional parts corresponding to appearance of the antiferroelectric (AFE) phase. The phenomena can be attributed to variation of the electronic structure during A-site driven phase transition.

  16. Improved Growth of High-Temperature Superconductors with HF Pressure

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACT EVALUATION PLAN FOR THE SITE-218 58 84 168 167Control - Energy

  17. DECONTAMINATION OF ZIRCALOY SPENT FUEL CLADDING HULLS

    SciTech Connect (OSTI)

    Rudisill, T; John Mickalonis, J

    2006-09-27

    The reprocessing of commercial spent nuclear fuel (SNF) generates a Zircaloy cladding hull waste which requires disposal as a high level waste in the geologic repository. The hulls are primarily contaminated with fission products and actinides from the fuel. During fuel irradiation, these contaminants are deposited in a thin layer of zirconium oxide (ZrO{sub 2}) which forms on the cladding surface at the elevated temperatures present in a nuclear reactor. Therefore, if the hulls are treated to remove the ZrO{sub 2} layer, a majority of the contamination will be removed and the hulls could potentially meet acceptance criteria for disposal as a low level waste (LLW). Discard of the hulls as a LLW would result in significant savings due to the high costs associated with geologic disposal. To assess the feasibility of decontaminating spent fuel cladding hulls, two treatment processes developed for dissolving fuels containing zirconium (Zr) metal or alloys were evaluated. Small-scale dissolution experiments were performed using the ZIRFLEX process which employs a boiling ammonium fluoride (NH{sub 4}F)/ammonium nitrate (NH{sub 4}NO{sub 3}) solution to dissolve Zr or Zircaloy cladding and a hydrofluoric acid (HF) process developed for complete dissolution of Zr-containing fuels. The feasibility experiments were performed using Zircaloy-4 metal coupons which were electrochemically oxidized to produce a thin ZrO{sub 2} layer on the surface. Once the oxide layer was in place, the ease of removing the layer using methods based on the two processes was evaluated. The ZIRFLEX and HF dissolution processes were both successful in removing a 0.2 mm (thick) oxide layer from Zircaloy-4 coupons. Although the ZIRFLEX process was effective in removing the oxide layer, two potential shortcomings were identified. The formation of ammonium hexafluorozirconate ((NH{sub 4}){sub 2}ZrF{sub 6}) on the metal surface prior to dissolution in the bulk solution could hinder the decontamination process by obstructing the removal of contamination. The thermal decomposition of this material is also undesirable if the cladding hulls are melted for volume reduction or to produce waste forms. Handling and disposal of the corrosive off-gas stream and ZrO{sub 2}-containing dross must be addressed. The stability of Zr{sup 4+} in the NHF{sub 4}/NH{sub 4}NO{sub 3} solution is also a concern. Precipitation of ammonium zirconium fluorides upon cooling of the dissolving solution was observed in the feasibility experiments. Precipitation of the solids was attributed to the high fluoride to Zr ratios used in the experiments. The solubility of Zr{sup 4+} in NH{sub 4}F solutions decreases as the free fluoride concentration increases. The removal of the ZrO{sub 2} layer from Zircaloy-4 coupons with HF showed a strong dependence on both the concentration and temperature. Very rapid dissolution of the oxide layer and significant amounts of metal was observed in experiments using HF concentrations {ge} 2.5 M. Treatment of the coupons using HF concentrations {le} 1.0 M was very effective in removing the oxide layer. The most effective conditions resulted in dissolution rates which were less than approximately 2 mg/cm{sup 2}-min. With dissolution rates in this range, uniform removal of the oxide layer was obtained and a minimal amount of Zircaloy metal was dissolved. Future HF dissolution studies should focus on the decontamination of actual spent fuel cladding hulls to determine if the treated hulls meet criteria for disposal as a LLW.

  18. Valence electronenergy-lossspectroscopystudyofZrSiO4 and ZrO2 (Journal

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory of rare Kaonfor Direct Measurement of2012: GenomicsofArticle)Patent:

  19. Trace element analysis of Texas lignite 

    E-Print Network [OSTI]

    Mahar, Sean

    1982-01-01

    , were discharged as gases. As, Cd, Cu, Ga, Mo, Pb, Se, and Zn were concentrated in the fly ash no't collected by the pre- cipitator and discharged through the stack. Al, Ba, CA, Ce. Co, Eu, Fe, Hf, K, La, Mg, Mn, Rb, Sc, Si, Sm, Sr, Ta, Th, and Ti..., Ge, Hf, I, K, La, Li, Na, Nb, P, Pd, Pt, S, Sc, Si, Sr, Ta, Te, Th, Ti, H, W, and Zr are included in Tables 15-19. These elements are extra, as they were not desired for the intended research, but analysis was made as a matter of course, so...

  20. Phase diagram and incommensurate antiferroelectric structure in (Pb{sub 1?1.5x}La{sub x})(Zr{sub 0.42}Sn{sub 0.40}Ti{sub 0.18})O{sub 3} ceramics discovered by band-to-band optical transitions

    SciTech Connect (OSTI)

    Ding, X. J.; Xu, L. P.; Hu, Z. G. Chu, J. H.; Chen, X. F.; Wang, G. S.; Dong, X. L.

    2014-09-29

    Optical properties and phase transitions of (Pb{sub 1?1.5x}La{sub x})(Zr{sub 0.42}Sn{sub 0.40}Ti{sub 0.18})O{sub 3} (PLZST 100x/42/40/18) ceramics with different compositions have been investigated by temperature dependent spectroscopic ellipsometry. Two interband critical points (E{sub cp1} and E{sub cp2}) located at about 3.9 and 5.1?eV can be obtained by fitting standard line shapes to the second derivatives of the complex dielectric functions. Based on the band-to-band transitions, the phase diagram of PLZST ceramics can be well presented. Moreover, a peculiar incommensurate antiferroelectric state has been found to exist above the temperature of the normal commensurate antiferroelectric tetragonal structure. It can be stable below Curie temperature, evolving slowly with decreasing temperature towards the commensurate structure, which is due to strong pinning of incommensurate domain walls. The phenomena can result from a competition between ferroelectric ordering and antiferroelectric ordering caused by the lanthanum modification.