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Sample records for ba ra zr

  1. The analysis of Ytrium doped BaZrO3

    Office of Scientific and Technical Information (OSTI)

    Enhanced Power Stability for Proton Conducting Solid Oxides Fuel Cells Report Title: Computational modeling, synthesis, and characterization of BaZr 1-x Y x O 3- solid state ...

  2. Geochemistry of Ca, Sr, Ba and Ra sulfates in some deep brines from the Palo Duro basin, Texas

    SciTech Connect (OSTI)

    Langmuir, D.; Melchior, D.

    1985-11-01

    The geochemistry of Ca, Sr, Ba and Ra sulfates in some deep brines from the Palo Duro Basin of north Texas, was studied to define geochemical controls on radionuclides such as /sup 90/Sr and /sup 226/Ra. Published solubility data for gypsum, anhydrite, celestite, barite and RaSO/sub 4/ were first reevaluated, in most cases using the ion interaction approach of Pitzer, to determine solubility products of the sulfates as a function of temperature and pressure. Ionic strengths of the brines were from 2.9 to 4.8 m, their temperatures and pressures up to 40/sup 0/C and 130 bars. Saturation indices of the sulfates were computed with the ion-interaction approach in one brine from the arkosic granite wash facies and four from the carbonate Wolfcamp Formation. All five brines are saturated with respect to gypsum, anhydrite and celestite, and three of the five with respect to barite. All are undersaturated by from 5 to 6 orders of magnitude with respect to pure RaSO/sub 4/. /sup 226/Ra concentrations in the brines, which ranged from 10/sup -11.3/ to 10/sup -12.7/ m, are not controlled by RaSO/sub 4/ solubility or adsorption, but possibly by the solubility of trace Ra solid solutions in sulfates including celestite and barite.

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

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    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.

  4. Continuous cross-over from ferroelectric to relaxor state and piezoelectric properties of BaTiO{sub 3}-BaZrO{sub 3}-CaTiO{sub 3} single crystals

    SciTech Connect (OSTI)

    Benabdallah, F.; Veber, P. Prakasam, M.; Viraphong, O.; Maglione, M.; Shimamura, K.

    2014-04-14

    Optimal properties like piezoelectricity can be found in polarizable materials for which the structure changes sharply under small composition variations in the vicinity of their morphotropic phase boundary or the triple point in their isobaric temperature-composition phase diagram. In the latter, lead-free (Ba{sub 0.850}Ca{sub 0.150})(Ti{sub 0.900}Zr{sub 0.100})O{sub 3} ceramics exhibit outstanding piezoelectric coefficients. For the first time, we report the growth of piezoelectric lead-free single crystals in the BaTiO{sub 3}-BaZrO{sub 3}-CaTiO{sub 3} pseudo-ternary system. The stoichiometry control in the CaO-BaO-TiO{sub 2}-ZrO{sub 2} solid solution led to single crystals with various compositions ranging from (Ba{sub 0.857}Ca{sub 0.143})(Ti{sub 0.928}Zr{sub 0.072})O{sub 3} to (Ba{sub 0.953}Ca{sub 0.047})(Ti{sub 0.427}Zr{sub 0.573})O{sub 3}. We evidenced a continuous cross-over from a ferroelectric state at high titanium content to a relaxor one on increasing the zirconium content. Such a property tuning is rather seldom observed in lead-free ferroelectrics and confirms what was already reported for ceramics. Single crystal with (Ba{sub 0.838}Ca{sub 0.162})(Ti{sub 0.854}Zr{sub 0.146})O{sub 3} composition, which has been grown and oriented along [001] crystallographic direction, displayed electromechanical coefficients d{sub 31} and k{sub 31} of 93 pC.N{sup −1} and 0.18, respectively, near the room temperature (T = 305 K)

  5. Comparative studies of dipole polarizabilities in Sr{sup +}, Ba{sup +}, and Ra{sup +} and their applications to optical clocks

    SciTech Connect (OSTI)

    Sahoo, B. K.; Timmermans, R. G. E.; Das, B. P.; Mukherjee, D.

    2009-12-15

    Static dipole polarizabilities are calculated in the ground and metastable states of Sr{sup +}, Ba{sup +} and Ra{sup +} using the relativistic coupled-cluster method. Trends of the electron correlation effects are investigated in these atomic ions. We also estimate the Stark and black-body radiation shifts from these results for these systems for the transitions proposed for the optical frequency standards and compare them with available experimental data.

  6. 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.

  7. Orthorhombic-tetragonal phase coexistence and enhanced piezo-response at room temperature in Zr, Sn, and Hf modified BaTiO{sub 3}

    SciTech Connect (OSTI)

    Kalyani, Ajay Kumar; Brajesh, Kumar; Ranjan, Rajeev; Senyshyn, Anatoliy

    2014-06-23

    The effect of Zr, Hf, and Sn in BaTiO{sub 3} has been investigated at close composition intervals in the dilute concentration limit. Detailed structural analysis by x-ray and neutron powder diffraction revealed that merely 2 mol. % of Zr, Sn, and Hf stabilizes a coexistence of orthorhombic (Amm2) and tetragonal (P4mm) phases at room temperature. As a consequence, all the three systems show substantial enhancement in the longitudinal piezoelectric coefficient (d{sub 33}), with Sn modification exhibiting the highest value ∼425 pC/N.

  8. Electrical conductivity spectra of Sn doped BaTi{sub 0.95}Zr{sub 0.05}O{sub 3}

    SciTech Connect (OSTI)

    Dalal, Biswajit; Sarkar, Babusona; De, S. K.

    2014-05-28

    The alternating current (ac) conductivity spectra of Sn doped BaTi{sub 0.95}Zr{sub 0.05}O{sub 3} prepared by solid state reaction have been studied in the temperature range of 373–473 K. Mixed valency of Sn atoms and the oxygen vacancy controls electrical transport process. The ac conductivity follows Jonscher type power law as a function of frequency. Derived dc conductivity and hopping frequency follow Arrhenius type temperature dependency and have same activation energy. Almost temperature independent nature of frequency exponent indicates that the electrical conduction in Zr and Sn co-doped BaTiO{sub 3} relaxor is quantum mechanical electron tunneling. The conductivity spectra are perfectly scaled using the scaling parameters as dc conductivity and hopping frequency.

  9. 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

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    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.

  10. Highly constrained ferroelectric [BaTiO{sub 3}]{sub (1−x)Λ}/[BaZrO{sub 3}]{sub xΛ} superlattices: X-ray diffraction and Raman spectroscopy

    SciTech Connect (OSTI)

    Belhadi, J.; El Marssi, M. Gagou, Y.; El Mendili, Y.; Bouyanfif, H.; Yuzyuk, Yu. I.; Raevski, I. P.; Wolfman, J.

    2014-07-21

    We report an x-ray diffraction (XRD) and a Raman-scattering investigation of ferroelectric/paraelectric superlattices [BaTiO{sub 3}] {sub (1−x)Λ}/[BaZrO{sub 3}]{sub xΛ} for which the composition varied, 0.15 ≤ x ≤ 0.85, while the superlattice (SL) modulation period Λ was kept constant at about 100 Å. The samples were epitaxially grown by pulsed laser deposition on MgO substrates buffered with La{sub 0.5}Sr{sub 0.5}CoO{sub 3}. Based on the XRD analysis and on polarized Raman spectra, we have showed that the large strain in SLs induced ferroelectricity in BaZrO{sub 3} (BZ) for all SLs, a material that is paraelectric in the bulk form at any temperature and in the single film. The induced polar axis in BZ layers is perpendicular to the plane of substrate while BaTiO{sub 3} (BT) layers exhibit in-plane polar orientation. Raman spectroscopy revealed a lattice ordering in SLs due to the misfit strain generated by the large lattice mismatch between the alternating BZ and BT layers. This strain induced a huge upward frequency of the lowest E(1TO) soft mode from 60 cm{sup −1} in the BT single film to 215 cm{sup −1} in the SL with x = 0.85. These results show that in spite of relatively large periodicity of SLs, they are highly constrained and the variation of BZ ratio allowed modifying strains between layers. The temperature dependence of the Raman spectra for BT{sub 0.3Λ}/BZ{sub 0.7Λ} and BT{sub 0.7Λ}/BZ{sub 0.3Λ} samples revealed giant shift of the ferroelectric phase transition. The phase transition temperature was found to be upshifted by about 300 °C with respect to BT single crystal.

  11. Softening of infrared-active mode of perovskite BaZrO{sub 3} proved by terahertz time-domain spectroscopy

    SciTech Connect (OSTI)

    Helal, M. A.; Mori, T.; Kojima, S.

    2015-05-04

    The low-frequency infrared-active optical modes were studied in a barium zirconate, BaZrO{sub 3}, single crystal with the perovskite structure using terahertz (THz) time-domain spectroscopy (TDS). The real and imaginary parts of the dielectric constants were accurately determined in the frequency range between 0.2 and 2.7 THz. Upon cooling from room temperature to 8 K, the lowest-frequency TO1 mode at 2.32 THz showed a pronounced softening to 1.94 THz. The real part of the dielectric constant at 0.5 THz determined by THz-TDS obeys Barrett's relation, and the existence of a plateau confirms that the quantum effects lead to saturation of the soft mode frequencies of the TO1 and TO2 modes below ≈20 K. This is reminiscent of incipient ferroelectrics with the perovskite structure such as CaTiO{sub 3}.

  12. Dielectric behavior of samarium-doped BaZr{sub 0.2}Ti{sub 0.8}O{sub 3} ceramics

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    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}.

  13. Two-Step Reactive Aid Sintering of BaZr0.8Y0.2O3-δ Proton-Conducting Ceramics

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

    Wang, Siwei; Chen, Yan; Zhang, Lingling; Ren, Cong; Chen, Fanglin; Brinkman, Kyle S.

    2015-10-14

    Ceramic-based proton conductors enable high-temperature hydrogen economy applications such as hydrogen separation membranes, fuel cells, and steam electrolyzers. BaZr0.8Y0.2O3-δ (BZY) proton-conducting oxide possesses the highest level of proton conductivity reported to date, but poor sinterability hinders its widespread utilization. Here, we report a two-step reactive aid sintering (TRAS) method involving the introduction of BaCO3 and B2O3-Li2O for the preparation of dense BZY ceramics sintered at 1500°C. The resulting BZY samples showed a pure perovskite structure with a dramatic increase in the relative density to 91.5%. In addition, the shrinkage during sintering was improved to 19.3% by a TRAS method asmore » compared to 2.6% by the conventional solid date reaction method. Moreover, the bulk conductivity was improved due to enhanced densification, while the grain boundary conductivity decreased due to the blocking behavior of the sintering aid resulting in a decrease in the total conductivity of the samples.« less

  14. In situ electric field induced domain evolution in Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}-0.3(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} ferroelectrics

    SciTech Connect (OSTI)

    Zakhozheva, M.; Kleebe, H.-J.; Schmitt, L. A.; Acosta, M.; Rödel, J.; Jo, W.

    2014-09-15

    In this work, the lead-free Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}-0.3(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} piezoelectric ceramic was investigated in situ under an applied electric field by transmission electron microscopy. Significant changes in domain morphology of the studied material have been observed under an applied electric field. During the poling process, the domain configurations disappeared, forming a single-domain state. This multi- to single-domain state transition occurred with the formation of an intermediate nanodomain state. After removing the electric field, domain configurations reappeared. Selected area electron diffraction during electrical poling gave no indication of any structural changes as for example reflection splitting. Rather, a contribution of the extrinsic effect to the piezoelectric response of the Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}-0.3(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} was found to be dominant.

  15. 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

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    Sturrock, P. A.; Fischbach, E.; Jenkins, J.

    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 4π 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.

  16. 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

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    Venkata Ramana, E.; Mahajan, A.; Graa, 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 303400 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 ferroelectricparaelectric 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

  17. Order parameter and scaling behavior in BaZr{sub x}Ti{sub 1?x}O{sub 3} (0.3 < x < 0.6) relaxor ferroelectrics

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    Usman, Muhammad; Mumtaz, Arif Raoof, Sobia; Hasanain, S. K.

    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.

  18. Two-Step Reactive Aid Sintering of BaZr0.8Y0.2O3-δ Proton-Conducting Ceramics

    SciTech Connect (OSTI)

    Wang, Siwei; Chen, Yan; Zhang, Lingling; Ren, Cong; Chen, Fanglin; Brinkman, Kyle S.

    2015-10-14

    Ceramic-based proton conductors enable high-temperature hydrogen economy applications such as hydrogen separation membranes, fuel cells, and steam electrolyzers. BaZr0.8Y0.2O3-δ (BZY) proton-conducting oxide possesses the highest level of proton conductivity reported to date, but poor sinterability hinders its widespread utilization. Here, we report a two-step reactive aid sintering (TRAS) method involving the introduction of BaCO3 and B2O3-Li2O for the preparation of dense BZY ceramics sintered at 1500°C. The resulting BZY samples showed a pure perovskite structure with a dramatic increase in the relative density to 91.5%. In addition, the shrinkage during sintering was improved to 19.3% by a TRAS method as compared to 2.6% by the conventional solid date reaction method. Moreover, the bulk conductivity was improved due to enhanced densification, while the grain boundary conductivity decreased due to the blocking behavior of the sintering aid resulting in a decrease in the total conductivity of the samples.

  19. Symmetry determination on Pb-free piezoceramic 0.5Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}-0.5(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} using convergent beam electron diffraction method

    SciTech Connect (OSTI)

    Gao, Jinghui Zhong, Lisheng; Zhang, Lixue; Xue, Dezhen; Kimoto, Takayoshi; Song, Minghui; Ren, Xiaobing

    2014-02-07

    (1−x)(Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}-x(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} (BZT-xBCT) Pb-free piezoceramic has been reported showing ultrahigh piezoelectric performance in its morphotropic phase boundary (MPB) region. However, the crystal structure characteristic for the MPB composition of BZT-xBCT is still under debate—between single orthorhombic phase and tetragonal + rhombohedral two phase mixture. In the present study, we perform the local symmetry determination on the MPB composition x = 0.5 using convergent beam electron diffraction analysis (CBED). Our CBED results from multiple zone axes suggest that there are two coexisting phases with the point group symmetries of 4 mm (tetragonal) and 3 m (rhombohedral) respectively, which agree with two phase mixture model. The strong piezoelectricity can thus be understood by considering the polarization rotation between tetragonal and rhombohedral phases by external field.

  20. Phase transitions and the piezoelectricity around morphotropic phase boundary in Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}-x(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} lead-free solid solution

    SciTech Connect (OSTI)

    Zhang, Le; Zhang, Ming; Wang, Liang; Zhou, Chao; Zhang, Zhen; Yao, Yonggang; Zhang, Lixue; Xue, Dezhen E-mail: xlou03@mail.xjtu.edu.cn Lou, Xiaojie E-mail: xlou03@mail.xjtu.edu.cn; Ren, Xiaobing E-mail: xlou03@mail.xjtu.edu.cn

    2014-10-20

    In this paper, two displacive phase transitions around the morphotropic phase boundary (MPB) in Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}-x(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} (BZT-xBCT) ceramics were detected by inspecting two anomalies of the Raman Ti{sup 4+}-O{sup 2−} longitudinal optical mode (∼725 cm{sup −1}). Further, permittivity and X-ray diffraction results demonstrated these two phase transitions originate from tetragonal (T) to rhombohedral (R) through an intermediate orthorhombic (O) phase. Importantly, we found that the maximum piezoelectric response (d{sub 33} = 545pC/N) was achieved at the boundary between the T and O phase, indicating that the giant piezoelectricity of BZT-xBCT may mainly stem from the T-O phase boundary due to easier polarization rotation and larger lattice softening.

  1. A comparative study of SrO and BaO doping to CeO{sub 2}-ZrO{sub 2}: Characteristic and its catalytic performance for three-way catalysts

    SciTech Connect (OSTI)

    Guo, Jiaxiu; National Engineering Research Center for Flue Gas Desulfurization, Chengdu 610065 ; Shi, Zhonghua; Wu, Dongdong; Yin, Huaqiang; National Engineering Research Center for Flue Gas Desulfurization, Chengdu 610065 ; Gong, Maochu; Chen, Yaoqiang; National Engineering Research Center for Flue Gas Desulfurization, Chengdu 610065

    2013-02-15

    Graphical abstract: Display Omitted Highlights: ► The prepared materials have a face-centered cubic structure and nanosize particles. ►Comparing to CZB, aged CZS has 494 μmol/g of OSC and 30 m{sup 2}/g of surface area. ► CZS and CZB have similar NO sorption and reductive properties and different H{sub 2} uptake. ► T{sub 50} of Pt-Rh/CZS/LA is as low as 199 °C for CO, 228 °C for NO, and 252 °C for C{sub 3}H{sub 8}. ► Pt-Rh/CZS/LA has wider working-window at 320 °C under different λ value. -- Abstract: Ceria-zirconia-strontia (Ce{sub 0.35}Zr{sub 0.55}Sr{sub 0.10}O{sub 1.9}) and ceria-zirconia-baria (Ce{sub 0.35}Zr{sub 0.55}Ba{sub 0.10}O{sub 1.9}) were synthesized using an oxidation-co-precipitation method with hydrogen peroxide (H{sub 2}O{sub 2}) as oxidant. The physical and chemical properties of the prepared materials were investigated using Brunauer–Emmett–Teller surface area characterization, transmission electron microscopy, X-ray diffraction, Raman spectra, X-ray photoelectron spectroscopy, and oxygen pulse reaction. The prepared materials were used in preparing three-way catalysts with low Pt and Rh content. Moreover, catalytic activities were evaluated at a fixed bed under a simulated gaseous mixture. The results are as follows: (1) the prepared materials have a face-centered cubic structure and are nano-sized; (2) aged Ce{sub 0.35}Zr{sub 0.55}Sr{sub 0.10}O{sub 1.9} has higher oxygen storage capacity (494 μmol/g), better thermal stability (30 m{sup 2}/g), good low-temperature reducibility, and high hydrogen uptake after TPR-redox cycles; (3) the light-off temperature (T{sub 50}) of Pt-Rh/CZS/LA can be as low as 199 °C for CO, 228 °C for NO, and 252 °C for C{sub 3}H{sub 8}; and (4) Pt-Rh/CZS/LA has a fairly wide working-window.

  2. 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

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    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.

  3. Rapid Method for Ra-226 and Ra-228 in Water Samples

    SciTech Connect (OSTI)

    Maxwell, Sherrod, L. III

    2006-02-10

    The measurement of radium isotopes in natural waters is important for oceanographic studies and for public health reasons. Ra-226 (1620 year half-life) is one of the most toxic of the long-lived alpha emitters present in the environment due to its long life and its tendency to concentrate in bones, which increases the internal radiation dose of individuals. The analysis of radium-226 and radium-228 in natural waters can be tedious and time-consuming. Different sample preparation methods are often required to prepare Ra-226 and Ra-228 for separate analyses. A rapid method has been developed at the Savannah River Environmental Laboratory that effectively separates both Ra-226 and Ra-228 (via Ac-228) for assay. This method uses MnO{sub 2} Resin from Eichrom Technologies (Darien, IL, USA) to preconcentrate Ra-226 and Ra-228 rapidly from water samples, along with Ba-133 tracer. DGA Resin{reg_sign} (Eichrom) and Ln-Resin{reg_sign} (Eichrom) are employed in tandem to prepare Ra-226 for assay by alpha spectrometry and to determine Ra-228 via the measurement of Ac-228 by gas proportional counting. After preconcentration, the manganese dioxide is dissolved from the resin and passed through stacked Ln-Resin-DGA Resin cartridges that remove uranium and thorium interferences and retain Ac-228 on DGA Resin. The eluate that passed through this column is evaporated, redissolved in a lower acidity and passed through Ln-Resin again to further remove interferences before performing a barium sulfate microprecipitation. The Ac-228 is stripped from the resin, collected using cerium fluoride microprecipitation and counted by gas proportional counting. By using vacuum box cartridge technology with rapid flow rates, sample preparation time is minimized.

  4. Microsoft Word - Ra-15

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

    Grant Funding OAS-RA-10-15 August 2010 Additional Information Special Report on "Review of the Department of Energy's Plan for Obligating Remaining Recovery Act Contract and Grant ...

  5. Large piezoelectricity in Pb-free 0.96(K{sub 0.5}Na{sub 0.5}){sub 0.95}Li{sub 0.05}Nb{sub 0.93}Sb{sub 0.07}O{sub 3}−0.04BaZrO{sub 3} ceramic: A perspective from microstructure

    SciTech Connect (OSTI)

    Gao, Jinghui Li, Huiying; Zhong, Lisheng; Li, Shengtao; Hao, Yanshuang; Ren, Shuai Fang, Minxia; Ren, Xiaobing; Kimoto, Takayoshi; Wang, Yu

    2015-02-28

    We employ transmission electron microscopy to explore the reason for large piezoelectricity (d{sub 33}≈400pC/N) in a Pb-free 0.96(K{sub 0.5}Na{sub 0.5}){sub 0.95}Li{sub 0.05}Nb{sub 0.93}Sb{sub 0.07}O{sub 3} −0.04BaZrO{sub 3} ceramic from microstructure. The result shows that the high piezoelectricity corresponds to a miniaturized nanodomain configuration in a domain hierarchy. The nanodomains disappear on heating accompanied by a reduction in d{sub 33} value. Further convergent beam electron diffraction study reveals a coexistence of tetragonal and orthorhombic phase, which indicates that large piezoelectricity of KNLNS{sub 0.07}-BZ may stem from easy polarization rotation due to low polarization anisotropy on the tetragonal-orthorhombic phase boundary.

  6. Phase transition sequence in Pb-free 0.96(K{sub 0.5}Na{sub 0.5}){sub 0.95}Li{sub 0.05}Nb{sub 0.93} Sb{sub 0.07}O{sub 3}−0.04BaZrO{sub 3} ceramic with large piezoelectric response

    SciTech Connect (OSTI)

    Gao, Jinghui Zhang, Le; Zhang, Ming; Dai, Ye; Hu, Xinghao; Wang, Dong; Zhong, Lisheng; Li, Shengtao; Ren, Shuai; Hao, Yanshuang Fang, Minxia; Ren, Xiaobing

    2015-07-20

    The piezoceramic 0.96(K{sub 0.5}Na{sub 0.5}){sub 0.95}Li{sub 0.05}Nb{sub 0.93}Sb{sub 0.07}O{sub 3}−0.04BaZrO{sub 3} (KNLNS{sub 0.07}-BZ), which shows large piezoelectric response (d{sub 33} ≈ 425 pC/N), has been considered as one of the promising Pb-free substitutions for Pb(Zr,Ti)O{sub 3}. In this paper, we investigate the phase transition sequence for KNLNS{sub 0.07}-BZ by employing the dielectric measurement, mechanical spectroscopy, as well as Raman spectroscopy. Two ferroelectric-ferroelectric transitions have been detected by inspecting anomalies in the spectra, indicating the existence of three ferroelectric phases. Moreover, in-situ X-ray diffraction study has been further performed on KNLNS{sub 0.07}-BZ to identify the crystal structure for each phase. The result reveals that the phase sequence for KNLNS{sub 0.07}-BZ evolves from tetragonal (T) to rhombohedral (R) via an intermediate orthorhombic (O) phase. And the piezoelectric-optimal region for KNLNS{sub 0.07}-BZ locates on a T-O boundary rather than the previously reported T-R boundary. Strong piezoelectricity may stem from the easier polarization rotation on the T-O boundary with reduced polarization anisotropy.

  7. Rapid method for the determination of 226Ra in hydraulic fracturing wastewater samples

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

    Maxwell, Sherrod L.; Culligan, Brian K.; Warren, Richard A.; McAlister, Daniel R.

    2016-03-24

    A new method that rapidly preconcentrates and measures 226Ra from hydraulic fracturing wastewater samples was developed in the Savannah River Environmental Laboratory. The method improves the quality of 226Ra measurements using gamma spectrometry by providing up to 100x preconcentration of 226Ra from this difficult sample matrix, which contains very high levels of calcium, barium, strontium, magnesium and sodium. The high chemical yield, typically 80-90%, facilitates a low detection limit, important for lower level samples, and indicates method ruggedness. Ba-133 tracer is used to determine chemical yield and correct for geometry-related counting issues. The 226Ra sample preparation takes < 2 hours.

  8. Co.ra

    Office of Legacy Management (LM)

    Co.ra ARGONNEX4TIONALI$S'ATGRY 'i' : .: glbo South Caea!Avenue Argenne, IAuilm3- 6owJ . I.,? , m-m-769/ 5 April 1965 ,- Mr. K. 0. Wasson Coors Porcelain Cowany tie1 Elanen% Building Golden, Colorado Dear Mr. Wasson: '* -.c,. *.-':-- ~., _, ., Under seprate cover our RuXhasing Departmeat is requesting a quote for six fuel specimens. Except for composition, the specimens are to be identical to the pieces identified by requisition number 702881. The six specimens shall have the following

  9. 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 <3 h. A rapid calcium phosphate precipitation method was used to pre-concentrate 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 <40 keV FWHM (full width half max). This new rapid method is fast, has very high tracer yield (>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

  10. Rapid determination of 226Ra in environmental samples

    SciTech Connect (OSTI)

    Maxwell, Sherrod L.; Culligan, Brian K.

    2012-02-04

    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.

  11. Investigation of ?-ZrH1.66/?-Zr interface in Zr-based Cladding...

    Office of Scientific and Technical Information (OSTI)

    Cladding Materials with Aberration-Corrected STEM. Citation Details In-Document Search Title: Investigation of ?-ZrH1.66?-Zr interface in Zr-based Cladding Materials with ...

  12. Rapid determination of 226Ra in emergency urine samples

    SciTech Connect (OSTI)

    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. The method was optimized for rapid turnaround times; urine samples may be prepared for counting in <3 h. A rapid calcium phosphate precipitation method was used to pre-concentrate 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 <40 keV FWHM (full width half max). This new rapid method is fast, has very high tracer yield (>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.

  13. 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 1z}Zr{sub z}O{sub 3?} (z=0, 0.01, 0.03, 0.05, 0.07, and 0.09) was synthesized by a solgel 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 0.5x}Sr{sub 0.5x}CoO? and a rhombohedral Ba{sub 1x}Sr{sub x}Co{sub 2y}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. Jnecke 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?}.

  14. Valence electronenergy-lossspectroscopystudyofZrSiO4 and ZrO2...

    Office of Scientific and Technical Information (OSTI)

    electronenergy-lossspectroscopystudyofZrSiO4 and ZrO2 ZrSiO4 (zircon) and m-ZrO2 (zirconia) are fundamental and industrially important materials.This work reports the detailed...

  15. Microstructure Characteristics of High Lift Factor MOCVD REBCO Coated Conductors With High Zr Content

    SciTech Connect (OSTI)

    Galstyan, E; Gharahcheshmeh, MH; Delgado, L; Xu, AX; Majkic, G; Selvamanickam, V

    2015-06-01

    We report the microstructural characteristics of high levels of Zr-added REBa2Cu3O7-x (RE = Gd, Y rare earth) coated conductors fabricated by Metal Organic Chemical Vapor Deposition (MOCVD). The enhancements of the lift factor defined as a ratio of the in-field (3 T, B parallel to c-axis) critical current density (J(c)) at 30 K and self-field J(c) at 77 K have been achieved for Zr addition levels of 20 and 25 mol% via optimization of deposition parameters. The presence of strong flux pinning is attributed to the aligned nanocolumns of BaZrO3 and nanoprecipitates embedded in REBa2Cu3O7-x matrix with good crystal quality. A high density of BZO nanorods with a typical size 6-8 nm and spacing of 20 nm has been observed. Moreover, the high Zr content was found to induce a high density of intrinsic defects, including stacking faults and dislocations. The correlation between in-field performance along the c-axis and microstructure of (Gd, Y) BCO film with a high level of Zr addition is discussed.

  16. High critical currents in heavily doped (Gd,Y)Ba2Cu3Ox superconductor tapes

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

    Selvamanickam, V.; Gharahcheshmeh, M. Heydari; Xu, A.; Galstyan, E.; Delgado, L.; Cantoni, C.

    2015-01-20

    REBa2Cu3Ox superconductor tapes with moderate levels of dopants have been optimized for high critical current density in low magnetic fields at 77 K, but they do not exhibit exemplary performance in conditions of interest for practical applications, i.e., temperatures less than 50 K and fields of 2–30 T. Heavy doping of REBCO tapes has been avoided by researchers thus far due to deterioration in properties. Here, we report achievement of critical current densities (Jc) above 20 MA/cm2 at 30 K, 3 T in heavily doped (25 mol. % Zr-added) (Gd,Y)Ba2Cu3Ox superconductor tapes, which is more than three times higher thanmore » the Jc typically obtained in moderately doped tapes. Pinning force levels above 1000 GN/m3 have also been attained at 20 K. A composition map of lift factor in Jc (ratio of Jc at 30 K, 3 T to the Jc at 77 K, 0 T) has been developed which reveals the optimum film composition to obtain lift factors above six, which is thrice the typical value. A highly c-axis aligned BaZrO3 (BZO) nanocolumn defect density of nearly 7 × 1011 cm–2 as well as 2–3nm sized particles rich in Cu and Zr have been found in the high Jc films.« less

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

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

    Energy Ra Power Management, Inc. (Incubator 10) PROJECT PROFILE: Ra Power Management, Inc. (Incubator 10) Project Title: RPM Asset Management Platform (AMP) Funding Opportunity: SunShot Technology to Market (Incubator 10) SunShot Subprogram: Technology to Market Location: Oakland, CA Amount Awarded: $500,000 Awardee Cost Share: $125,000 Project Investigator: Aaron Iverson Ra Power Management, Inc. (RPM) is developing a cloud-based software platform that manages the financial and operational

  18. Attendees- December 2014 P&RA Technical Exchange Meeting

    Office of Energy Efficiency and Renewable Energy (EERE)

    Attendees to the Performance & Risk Assessment Community of Practice (P&RA) Technical Exchange Meeting held in Las Vegas, Nevada on December 11 & 12, 2014.

  19. Ra Solar Systems Solutions SL | Open Energy Information

    Open Energy Info (EERE)

    Ra Solar Systems & Solutions SL Place: Madrid, Spain Zip: 28033 Sector: Solar Product: Spanish project developer and finance arranger for large-scale solar farms; also acts as...

  20. 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.

  1. 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

    Rainfall Manipulation Plots facility (RaMPs) is a unique experimental infrastructure that allows us to manipulate precipitation events and temperature, and assess population community, and ecosystem responses in native grassland. This facility allows us to manipulate the amount and timing of individual precipitation events in replicated field plots at the Konza Prairie Long-Term Ecological Research (LTER) site. Questions we are addressing include: • What is the relative importance of more extreme precipitation patterns (increased climatic variability) vs. increased temperatures (increased climatic mean) with regard to their impact on grassland ecosystem structure and function? Both projected climate change factors are predicted to decrease soil water availability, but the mechanisms by which this resource depletion occurs differ. • Will altered precipitation patterns, increased temperatures and their interaction increase opportunities for invasion by exotic species? • Will long-term (6-10 yr) trajectories of community and ecosystem change in response to more extreme precipitation patterns continue at the same rate as initial responses from years 1-6? Or will non-linear change occur as potential ecological thresholds are crossed? And will increased temperatures accelerate these responses? Data sets are available as ASCII files, in Excel spreadsheets, and in SAS format. (Taken from http://www.konza.ksu.edu/ramps/backgrnd.html

  2. Performance & Risk Assessment Community of Practice (P&RA CoP...

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

    Performance & Risk Assessment Community of Practice (P&RA CoP) Performance & Risk Assessment Community of Practice (P&RA CoP) P&RA CoP's Technical Exchange Meeting held on December ...

  3. 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.

  4. The Advanced Research Projects, OAS-RA-11-11

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

    Research Projects Agency - Energy OAS-RA-11-11 August 2011 Department of Energy Washington, DC 20585 August 22, 2011 MEMORANDUM FOR THE DIRECTOR, ADVANCED RESEARCH PROJECTS AGENCY ...

  5. Materials Data on BaZrN2 (SG:129) by Materials Project

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  6. Enhanced pinning in YBCO films with BaZrO.sub.3 nanoparticles

    DOE Patents [OSTI]

    Driscoll, Judith L.; Foltyn, Stephen R.

    2010-06-15

    A process and composition of matter are provided and involve flux pinning in thin films of high temperature superconductive oxides such as YBCO by inclusion of particles including barium and a group 4 or group 5 metal, such as zirconium, in the thin film.

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

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

    Rojas, J. V.; Woodward, J. D.; Chen, N.; Rondinone, A. J.; Castano, C. H.; Mirzadeh, S.

    2015-03-19

    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)more » 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.« less

  8. (U,Zr)N alloy having enhanced thermal stability

    DOE Patents [OSTI]

    Potter, Ralph A.; Scott, James L.

    1977-01-01

    A nitrided alloy of uranium and zirconium is provided which consists of a single-phase UN structure containing a dissolved amount of Zr as ZrN, effective to inhibit dissociation of the UN phase.

  9. Ba{sub 2}phenanthrene is the main component in the Ba-doped phenanthrene superconductor

    SciTech Connect (OSTI)

    Yan, Xun-Wang; Huang, Zhongbing; Lin, Hai-Qing

    2014-12-14

    We have systematically investigated the crystal structure of Ba-doped phenanthrene with various Ba doping levels by the first-principles calculations combined with the X-ray diffraction (XRD) spectra simulations. Although the experimental stoichiometry ratio of Ba atom and phenanthrene molecule is 1.5:1, the simulated XRD spectra, space group symmetry and optimized lattice parameters of Ba{sub 1.5}phenanthrene are not consistent with the experimental ones, while the results for Ba{sub 2}phenanthrene are in good agreement with the measurements. The strength difference of a few XRD peaks can be explained by the existence of pristine phenanthrene. Our findings suggest that instead of uniform Ba{sub 1.5}phenanthrene, there coexist Ba{sub 2}phenanthrene and undoped phenanthrene in the superconducting sample. The electronic calculations indicate that Ba{sub 2}phenanthrene is a semiconductor with a small energy gap less than 0.05 eV.

  10. RAPID DETERMINATION OF RA-226 IN ENVIRONMENTAL SAMPLES

    SciTech Connect (OSTI)

    Maxwell, S.

    2012-01-03

    A new rapid method for the determination of {sup 226}Ra in environmental samples has been developed at the Savannah River Site Environmental Lab (Aiken, SC, USA) that can be used for emergency response or routine sample analyses. The need for rapid analyses in the event of a Radiological Dispersive Device or Improvised Nuclear Device event is well-known. In addition, the recent accident at Fukushima Nuclear Power Plant in March, 2011 reinforces the need to have rapid analyses for radionuclides in environmental samples in the event of a nuclear accident. {sup 226}Ra (T1/2 = 1,620 years) is one of the most toxic of the long-lived alpha-emitters present in the environment due to its long life and its tendency to concentrate in bones, which increases the internal radiation dose of individuals. The new method to determine {sup 226}Ra in environmental samples utilizes a rapid sodium hydroxide fusion method for solid samples, calcium carbonate precipitation to preconcentrate Ra, and rapid column separation steps to remove interferences. The column separation process uses cation exchange resin to remove large amounts of calcium, Sr Resin to remove barium and Ln Resin as a final purification step to remove {sup 225}Ac and potential interferences. The purified {sup 226}Ra sample test sources are prepared using barium sulfate microprecipitation in the presence of isopropanol for counting by alpha spectrometry. The method showed good chemical recoveries and effective removal of interferences. The determination of {sup 226}Ra in environmental samples can be performed in less than 16 h for vegetation, concrete, brick, soil, and air filter samples with excellent quality for emergency or routine analyses. The sample preparation work takes less than 6 h. {sup 225}Ra (T1/2 = 14.9 day) tracer is used and the {sup 225}Ra progeny {sup 217}At is used to determine chemical yield via alpha spectrometry. The rapid fusion technique is a rugged sample digestion method that ensures that any

  11. 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 e550 eV using the KramersKronig 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 ~1516 eV and ~2527 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.

  12. Upcoming P&RA CoP Activities | Department of Energy

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

    Upcoming P&RA CoP Activities Upcoming P&RA CoP Activities Upcoming Activities Software QA requirements for supporting environmental management decisions (TBD). Annual Technical Exchange Meeting (October, 2016; Date & Location TBD)

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

  14. Audit Letter Report: OAS-RA-L-10-09 | Department of Energy

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

    9 Audit Letter Report: OAS-RA-L-10-09 August 27, 2010 Office of Science's Energy Frontier ... Topic: Science & Innovation Audit Letter Report: OAS-RA-L-10-09 (107.26 KB) More Documents ...

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

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

    5 Audit Report: OAS-RA-13-15 March 21, 2013 The Department of Energy's Industrial Carbon ... Topic: Financial Asssitance Audit Report: OAS-RA-13-15 (466.71 KB) More Documents & ...

  16. Audit Report: OAS-RA-L-12-05 | Department of Energy

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

    2-05 Audit Report: OAS-RA-L-12-05 July 10, 2012 Follow-up on the Department of Energy's ... Components Program under the American Recovery and Reinvestment Act (OAS-RA-L-10-04). ...

  17. Audit Report: OAS-RA-11-14 | Department of Energy

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

    4 Audit Report: OAS-RA-11-14 August 25, 2011 The Department of Energy's Weatherization ... Weatherization Assistance Program," (OAS-RA-10-11), identified several issues that ...

  18. Audit Report: OAS-RA-13-07 | Department of Energy

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

    7 Audit Report: OAS-RA-13-07 January 17, 2013 The Department of Energy's Weatherization ... Topic: Financial Assistance Audit Report: OAS-RA-13-07 (566.45 KB) More Documents & ...

  19. Audit Letter Report: OAS-RA-L-10-02 | Department of Energy

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

    2 Audit Letter Report: OAS-RA-L-10-02 April 16, 2010 Audit of Fermi National Accelerator ... Topic: Science & Innovation Audit Letter Report: OAS-RA-L-10-02 (94.57 KB) More Documents ...

  20. Audit Report: OAS-RA-11-17 | Department of Energy

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

    7 Audit Report: OAS-RA-11-17 September 19, 2011 The Department of Energy's Weatherization ... Topic: Financial Assistance Audit Report: OAS-RA-11-17 (706.78 KB) More Documents & ...

  1. Audit Report: OAS-RA-12-08 | Department of Energy

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

    8 Audit Report: OAS-RA-12-08 April 19, 2012 The Department of Energy's American Recovery ... Topic: Financial Assistance Audit Report: OAS-RA-12-08 (1.84 MB) More Documents & ...

  2. Examination Report: OAS-RA-13-04 | Department of Energy

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

    4 Examination Report: OAS-RA-13-04 November 8, 2012 The Department of Energy's American ... Topic: Financial Assistance Examination Report: OAS-RA-13-04 (1.34 MB) More Documents & ...

  3. Audit Report: OAS-RA-10-02 | Department of Energy

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

    2 Audit Report: OAS-RA-10-02 December 3, 2009 Management Alert on the Department's ... Topic: Financial Assistance Audit Report: OAS-RA-10-02 (138.19 KB) More Documents & ...

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

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

    1 Special Report: OAS-RA-10-01 October 21, 2009 The Department of Energy's Quality ... Topic: Financial Assistance Special Report: OAS-RA-10-01 (133.68 KB) More Documents & ...

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

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

    8 Audit Report: OAS-RA-13-28 July 18, 2013 Costs Incurred by Selected Tribal Energy ... TOPIC: Financial Assistance AUDIT REPORT: OAS-RA-13-28 (545.92 KB) More Documents & ...

  6. Audit Report: OAS-RA-11-13 | Department of Energy

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

    13 Audit Report: OAS-RA-11-13 August 23, 2011 The Department of Energy's Weatherization ... Topic: Financial Assistance Audit Report: OAS-RA-11-13 (398.06 KB) More Documents & ...

  7. Examination Report: OAS-RA-13-24 | Department of Energy

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

    4 Examination Report: OAS-RA-13-24 June 18, 2013 Southwest Michigan Community Action ... TOPIC: Energy OAS-RA-13-24.pdf (1.91 MB) More Documents & Publications Examination Report: ...

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

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

    2 Audit Report: OAS-RA-12-12 May 22, 2012 The Department of Energy's Clean Cities ... Topic: Financial Assistance Audit Report: OAS-RA-12-12 (761.22 KB) More Documents & ...

  9. Special Report: OAS-RA-10-04 | Department of Energy

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

    4 Special Report: OAS-RA-10-04 February 19, 2010 Progress in Implementing the Department ... Topic: Financial Assistance Special Report: OAS-RA-10-04 (232.52 KB) More Documents & ...

  10. Audit Report: OAS-RA-L-11-01 | Department of Energy

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

    1 Audit Report: OAS-RA-L-11-01 November 10, 2010 Management of the Plutonium Finishing ... Topic: Environmental Cleanup Audit Report: OAS-RA-L-11-01 (129.83 KB) More Documents & ...

  11. Audit Report: OAS-RA-L-11-13 | Department of Energy

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

    3 Audit Report: OAS-RA-L-11-13 September 30, 2011 The 12 GeV CEBAF Upgrade Project at ... Topic: Science & Innovation Audit Report: OAS-RA-L-11-13 (86.05 KB) More Documents & ...

  12. Audit Report: OAS-RA-11-15 | Department of Energy

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

    5 Audit Report: OAS-RA-11-15 August 25, 2011 Los Alamos National Laboratory Environmental ... Topic: Environmental Cleanup Audit Report: OAS-RA-11-15 (125.15 KB) More Documents & ...

  13. Audit Report: OAS-RA-10-06 | Department of Energy

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

    06 Audit Report: OAS-RA-10-06 April 1, 2010 Accounting and Reporting for the American ... Topic: Management & Administration Audit Report: OAS-RA-10-06 (163.51 KB) More Documents & ...

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

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

    10 Audit Report: OAS-RA-10-10 May 25, 2010 Waste Processing and Recovery Act Acceleration ... Topic: Environmental Cleanup Audit Report: OAS-RA-10-10 (658.07 KB) More Documents & ...

  15. Audit Report: OAS-RA-L-11-09 | Department of Energy

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

    9 Audit Report: OAS-RA-L-11-09 July 7, 2011 Performance of Recovery Act Funds at the Waste ... Topic: Environmental Cleanup Audit Report: OAS-RA-L-11-09 (99.67 KB) More Documents & ...

  16. Examination Report: OAS-RA-13-12 | Department of Energy

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

    12 Examination Report: OAS-RA-13-12 February 19, 2013 City of Los Angeles - Energy ... Topic: Financial Assistance Examination Report: OAS-RA-13-12 (790.07 KB) More Documents & ...

  17. Audit Report: OAS-RA-12-07 | Department of Energy

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

    7 Audit Report: OAS-RA-12-07 April 6, 2012 The Department of Energy's Weatherization ... Topic: Financial Assistance Audit Report: OAS-RA-12-07 (528.89 KB) More Documents & ...

  18. Audit Letter Report: OAS-RA-L-10-06 | Department of Energy

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

    6 Audit Letter Report: OAS-RA-L-10-06 September 15, 2010 The Department of Energy's ... Topic: Financial Assistance Audit Letter Report: OAS-RA-L-10-06 (140.87 KB) More Documents ...

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

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

    6 Audit Report: OAS-RA-12-06 February 22, 2012 The Management of Post-Recovery Act ... Topic: Human Resources Audit Report: OAS-RA-12-06 (250 KB) More Documents & Publications ...

  20. Audit Report: OAS-RA-14-04 | Department of Energy

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

    4 Audit Report: OAS-RA-14-04 June 17, 2014 Selected Activities of the Office of Energy ... Topic: Financial Assistance Audit Report: OAS-RA-14-04 (334.32 KB) More Documents & ...

  1. Examination Report: OAS-RA-L-12-07 | Department of Energy

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

    L-12-07 Examination Report: OAS-RA-L-12-07 September 20, 2012 The Department of Energy's ... Topic: Financial Assistance Examination Report: OAS-RA-L-12-07 (2.05 MB) More Documents & ...

  2. Audit Report: OAS-RA-11-12 | Department of Energy

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

    2 Audit Report: OAS-RA-11-12 August 22, 2011 The Department of Energy's Weatherization ... Topic: Financial Assistance Audit Report: OAS-RA-11-12 (2.6 MB) More Documents & ...

  3. Audit Special Report: OAS-RA-10-03 | Department of Energy

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

    OAS-RA-10-03 Audit Special Report: OAS-RA-10-03 December 7, 2009 Selected Department of Energy Program Efforts to Implement the American Recovery and Reinvestment Act The American ...

  4. Audit Report: OAS-RA-12-13 | Department of Energy

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

    3 Audit Report: OAS-RA-12-13 June 25, 2012 The Department of Energy's Weatherization ... Topic: Financial Assistance Audit Report: OAS-RA-12-13 (561.48 KB) More Documents & ...

  5. Examination Report: OAS-RA-12-05 | Department of Energy

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

    Examination Report: OAS-RA-12-05 Examination Report: OAS-RA-12-05 January 20, 2012 Saratoga County Economic Opportunity Council, Inc. -Weatherization Assistance Program Funds ...

  6. 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 Examination Report: OAS-RA-13-05 January 17, 2013 Prince George's County Department of Housing and Community Development - Weatherization ...

  7. Audit Report: OAS-RA-L-11-08 | Department of Energy

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

    8 Audit Report: OAS-RA-L-11-08 May 19, 2011 Use of American Recovery and Reinvestment Act ... Topic: Environmental Cleanup Audit Report: OAS-RA-L-11-08 (108.8 KB) More Documents & ...

  8. Audit Report: OAS-RA-11-02 | Department of Energy

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

    2 Audit Report: OAS-RA-11-02 November 2, 2010 Selected Aspects of the Commonwealth of ... Topic: Financial Assistance Audit Report: OAS-RA-11-02 (231.31 KB) More Documents & ...

  9. Preliminary Audit Report: OAS-RA-10-11 | Department of Energy

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

    Preliminary Audit Report: OAS-RA-10-11 Preliminary Audit Report: OAS-RA-10-11 May 26, 2010 Management Controls over the Commonwealth of Virginia's Efforts to Implement the American ...

  10. Audit Report: OAS-RA-09-04 | Department of Energy

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

    09-04 Audit Report: OAS-RA-09-04 September 4, 2009 Department of Energy's Efforts to Meet ... Topic: Management and Administration Audit Report: OAS-RA-09-04 (1.75 MB) More Documents & ...

  11. Audit Report: OAS-RA-12-04 | Department of Energy

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

    4 Audit Report: OAS-RA-12-04 January 20, 2012 The Department's Management of the Smart ... Topic: Financial Assistance Audit Report: OAS-RA-12-04 (365.11 KB) More Documents & ...

  12. Audit Report: OAS-RA-L-11-10 | Department of Energy

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

    0 Audit Report: OAS-RA-L-11-10 July 21, 2011 Department of Energy's Controls over Recovery ... Topic: Environmental Cleanup Audit Report: OAS-RA-L-11-10 (275.01 KB) More Documents & ...

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

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

    L-14-01 Special Report: OAS-RA-L-14-01 April 14, 2014 Allegations Regarding the Department ... Topic: Management and Administration Special Report: OAS-RA-L-14-01 (118.07 KB) More ...

  14. Special Report: OAS-RA-L-12-01 | Department of Energy

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

    L-12-01 Special Report: OAS-RA-L-12-01 November 28, 2011 Special Inquiry on the Office of ... Topic: Management & Administration Special Report: OAS-RA-L-12-01 (109.71 KB) More ...

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

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

    RA-L-12-01 Inspection Report: INS-RA-L-12-01 December 16, 2011 Waste Disposal and Recovery Act Efforts at the Oak Ridge Reservation The Department of Energy (Department) expends ...

  16. Audit Report: OAS-RA-L-11-03 | Department of Energy

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

    3 Audit Report: OAS-RA-L-11-03 February 9, 2011 Management of the Tank Farm Recovery Act ... Topic: Environmental Cleanup Audit Report: OAS-RA-L-11-03 (79.04 KB) More Documents & ...

  17. Investigative Report: INV-RA-11-01 | Department of Energy

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

    Investigative Report: INV-RA-11-01 Investigative Report: INV-RA-11-01 December 3, 2010 Management Alert on the State Energy Efficient Appliance Rebate Program The purpose of this ...

  18. Audit Report: OAS-RA-L-11-04 | Department of Energy

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

    1-04 Audit Report: OAS-RA-L-11-04 March 2, 2011 The Department's Infrastructure ... Topic: Management & Administration Audit Report: OAS-RA-L-11-04 (87.38 KB) More Documents ...

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

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

    1 Special Report: OAS-RA-14-01 October 31, 2013 Recent Events Related to Ecotality, Inc. ... Million in Funding to Ecotality, Inc. (OAS-RA-13-29, July 2013), we found that the ...

  20. Audit Report: OAS-RA-11-05 | Department of Energy

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

    5 Audit Report: OAS-RA-11-05 March 22, 2011 The Department of Energy's Geothermal ... Topic: Energy Audit Report: OAS-RA-11-05 (4.36 MB) More Documents & Publications Revised ...

  1. Audit Report: OAS-RA-L-12-02 | Department of Energy

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

    2-02 Audit Report: OAS-RA-L-12-02 January 12, 2012 Recovery Act Funded Projects at the ... Topic: Management & Administration Audit Report: OAS-RA-L-12-02 (100.04 KB) More Documents ...

  2. Audit Report: OAS-RA-11-09 | Department of Energy

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

    9 Audit Report: OAS-RA-11-09 June 13, 2011 The Department of Energy's Weatherization ... Topic: Financial Assistance Audit Report: OAS-RA-11-09 (995.84 KB) More Documents & ...

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

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

    Examination Report: OAS-RA-13-02 Examination Report: OAS-RA-13-02 October 9, 2012 County of Los Angeles - Energy Efficiency and Conservation Block Grant Program Funds Provided by ...

  4. Audit Report: OAS-RA-12-11 | Department of Energy

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

    11 Audit Report: OAS-RA-12-11 May 10, 2012 The Department of Energy's Transportation ... Topic: Financial Assistance Special Report: OAS-RA-12-11 (109.56 KB) More Documents & ...

  5. Audit Letter Report: OAS-RA-L-10-04 | Department of Energy

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

    4 Audit Letter Report: OAS-RA-L-10-04 April 27, 2010 Progress in Implementing the Advanced ... Topic: Financial Assistance Audit Letter Report: OAS-RA-L-10-04 (69.61 KB) More Documents ...

  6. Audit Report: OAS-RA-10-17 | Department of Energy

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

    7 Audit Report: OAS-RA-10-17 September 21, 2010 Status Report: The Department of Energy's ... Topic: Financial Assistance Audit Report: OAS-RA-10-17 (624.07 KB) More Documents & ...

  7. Audit Report: OAS-RA-10-18 | Department of Energy

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

    8 Audit Report: OAS-RA-10-18 September 29, 2010 Management Controls over the Department of ... Topic: Financial Assistance Audit Report: OAS-RA-10-18 (649.61 KB) More Documents & ...

  8. Audit Report: OAS-RA-L-11-02 | Department of Energy

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

    2 Audit Report: OAS-RA-L-11-02 December 20, 2010 Audit of Environmental Cleanup Projects ... Topic: Environmental Cleanup Audit Report: OAS-RA-L-11-02 (123.69 KB) More Documents & ...

  9. Examination Report: OAS-RA-13-21 | Department of Energy

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

    1 Examination Report: OAS-RA-13-21 May 14, 2013 South Carolina Energy Office - Energy ... TOPIC: Financial Assistance Examination Report: OAS-RA-13-21 (245.49 KB) More Documents & ...

  10. Audit Report: OAS-RA-L-11-12 | Department of Energy

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

    2 Audit Report: OAS-RA-L-11-12 September 29, 2011 Implementation of the Recovery Act at ... Topic: Environmental Cleanup Audit Report: OAS-RA-L-11-12 (79.15 KB) More Documents & ...

  11. Audit Report: OAS-RA-11-01 | Department of Energy

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

    1 Audit Report: OAS-RA-11-01 October 14, 2010 The State of Illinois Weatherization ... Topic: Financial Assistance Audit Report: OAS-RA-11-01 (898.49 KB) More Documents & ...

  12. Audit Report: OAS-RA-L-13-04 | Department of Energy

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

    4 Audit Report: OAS-RA-L-13-04 July 9, 2013 Modular Office Facilities for Recovery Act ... TOPIC: Management & Administration Audit Report: OAS-RA-L-13-04 (364.66 KB) More Documents ...

  13. Audit Report: OAS-RA-11-11 | Department of Energy

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

    1 Audit Report: OAS-RA-11-11 August 22, 2011 The Advanced Research Projects The Advanced ... Topic: Management & Administration Audit Report: OAS-RA-11-11 (772.55 KB) More Documents & ...

  14. Performance & Risk Assessment Community of Practice (P&RA CoP...

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

    Performance & Risk Assessment Community of Practice (P&RA CoP) Technical Exchanges Performance & Risk Assessment Community of Practice (P&RA CoP) Technical Exchanges PA CoP has ...

  15. Attendees - December 15-16, 2015 P&RA Technical Exchange Meeting |

    Office of Environmental Management (EM)

    Department of Energy 15-16, 2015 P&RA Technical Exchange Meeting Attendees - December 15-16, 2015 P&RA Technical Exchange Meeting Attendees to the December 15-16, 2015 P&RA Technical Exchange Meeting. Attendees (10.35 KB) More Documents & Publications Attendees - December 2014 P&RA Technical Exchange Meeting Status Updates on the Performance and Risk Assessment Community of Practice Status Updates on the Performance and Risk Assessment Community of Practice (P&RA CoP)

  16. Crystal structure of high-Zr inclusions in an alloy containing U, Pu, Np, Am, Zr and rare-earth elements

    SciTech Connect (OSTI)

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

    2014-05-01

    Researchers commonly observe high-Zr inclusions in actinide-Zr alloys. As there is very little published data on the crystal structures of these inclusions, it has generally been assumed that the inclusions were impurity-stabilized a-Zr. However, new electron-diffraction data from two high-Zr inclusions in an alloy containing U, Pu, Np, Am, Zr, and rare-earth elements show that these inclusions are not a-Zr (which has a hexagonal structure) but instead have a face-centered cubic structure. This data is unique in that it combines single-crystal diffraction patterns and microchemical analyses from individual inclusions. More data on other high-Zr inclusions is clearly required. However, the present results suggest that caution is needed in assuming that all high-Zr inclusions in actinide-Zr alloys are a-Zr.

  17. Irradiation induced structural change in Mo2Zr intermetallic phase

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

    Gan, J.; Keiser, Jr., D. D.; Miller, B. D.; Eriksson, N.; Sohn, Y. H.; Kirk, M.

    2016-05-14

    The Mo2Zr phase has been identified as a major interaction product at the interface of U-10Mo and Zr. Transmission electron microscopy in-situ irradiation with Kr ions at 200 °C with doses up to 2.0E + 16 ions/cm2 was carried out to investigate the radiation stability of the Mo2Zr. The Mo2Zr undergoes a radiation-induced structural change, from a large cubic (cF24) to a small cubic (cI2), along with an estimated 11.2% volume contraction without changing its composition. The structural change begins at irradiation dose below 1.0E + 14 ions/cm2. Furthermore, the transformed Mo2Zr phase demonstrates exceptional radiation tolerance with the developmentmore » of dislocations without bubble formation.« less

  18. 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.

  19. P&RA CoP Webinars | Department of Energy

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

    Services » Site & Facility Restoration » P&RA Community of Practice » P&RA CoP Webinars P&RA CoP Webinars Topics of interest to the CoP have been identified with the help of the steering committee, and will be discussed in quarterly Webinars. List of Topics for Interagency Performance & Risk Assessment Community of Practice (P&RA CoP) Discussion May 16, 2016 Webinar - Predicting the Service Life of Geomembranes in Low-Level and Mixed-Waste Disposal Facilities

  20. Measurements of structural and chemical order in Zr80Pt20 and Zr77Rh23 liquids

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

    Johnson, M. L.; Blodgett, M. E.; Lokshin, K. A.; Mauro, N. A.; Neuefeind, J.; Pueblo, C.; Quirinale, D. G.; Vogt, A. J.; Egami, T.; Goldman, A. I.; et al

    2016-02-03

    In this study, the short-range order (SRO) and medium-range order of electrostatically levitated Zr80Pt20 and Zr77Rh23 liquids are presented founded on a combination of high-energy x-ray diffraction and time-of-flight neutron diffraction studies. The atomic structures of the Zr80Pt20 liquids were determined as a function of temperature from constrained reverse Monte Carlo simulations using x-ray and elastic neutron scattering measurements and two partial pair-distribution functions obtained from molecular dynamics (MD) simulations.

  1. An Exceptionally Stable, Porphyrinic Zr Metal-Organic Framework...

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

    An Exceptionally Stable, Porphyrinic Zr Metal-Organic Framework Exhibiting pH-Dependent Fluorescence Previous Next List Hai-Long Jiang, Dawei Feng, Kecheng Wang, Zhi-Yuan Gu, ...

  2. 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.

  3. Construction of Ultrastable Porphyrin Zr Metal-Organic Frameworks...

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

    A series of highly stable MOFs with 3-D nanochannels, namely PCN-224 (no metal, Ni, Co, Fe), have been assembled with six-connected Zr6 cluster and metalloporphyrins by a...

  4. Crystal Structure and Thermodynamic Stability of Ba/Ti-Substituted Pollucites for Radioactive Cs/Ba Immobilization

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

    Xu, Hongwu; Chavez, Manuel E.; Mitchell, Jeremy N.; Garino, Terry J.; Schwarz, Haiqing L.; Rodriguez, Mark A.; Rademacher, David X.; Nenoff, Tina Maria

    2015-04-23

    An analogue of the mineral pollucite (CsAlSi2O6), CsTiSi2O6.5 has a potential host phase for radioactive Cs. However, as 137Cs and 135Cs transmute to 137Ba and 135Ba, respectively, through the beta decay, it is essential to study the structure and stability of this phase upon Cs → Ba substitution. In this work, two series of Ba/Ti-substituted samples, CsxBa(1-x)/2TiSi2O6.5 and CsxBa1-xTiSi2O7-0.5x, (x = 0.9 and 0.7), were synthesized by high-temperature crystallization from their respective precursors. Synchrotron X-ray diffraction and Rietveld analysis reveal that while CsxBa(1-x)/2TiSi2O6.5 samples are phase-pure, CsxBa1-xTiSi2O7-0.5x samples contain Cs3x/(2+x)Ba(1-x)/(2+x)TiSi2O6.5 pollucites (i.e., also two-Cs-to-one-Ba substitution) and a secondary phase, fresnoitemore » (Ba2TiSi2O8). Thus, the CsxBa1-xTiSi2O7-0.5x series is energetically less favorable than CsxBa(1-x)/2TiSi2O6.5. To study the stability systematics of CsxBa(1-x)/2TiSi2O6.5 pollucites, high-temperature calorimetric experiments were performed at 973 K with or without the lead borate solvent. Enthalpies of formation from the constituent oxides (and elements) have thus been derived. Our results show that with increasing Ba/(Cs + Ba) ratio, the thermodynamic stability of these phases decreases with respect to their component oxides. Hence, from the energetic viewpoint, continued Cs → Ba transmutation tends to destabilize the parent silicotitanate pollucite structure. However, the Ba-substituted pollucite co-forms with fresnoite (which incorporates the excess Ba), thereby providing viable ceramic waste forms for all the Ba decay products.« less

  5. A correlation between soil descriptions and {sup 226}Ra concentrations in Florida soils

    SciTech Connect (OSTI)

    Harrison, D.P.

    1992-12-31

    The soil radium content in Florida is highly variable. The range in radium concentrations, where the samples involved in this study are concerned, is from 0.1 pCi/g to 18.5 pCi/g. Low {sup 226}Ra concentrations (0.1 to 5 pCi/g) are evidenced in sands, moderate concentrations (5 to 11 pCi/g) are found in silt and gravel, and high {sup 226}Ra concentrations (>11 pCi/g) are found in soil horizons with shell, clay, and strata with phosphate. Strata containing phosphate yields a high concentration of {sup 226}Ra. The information obtained in this study, soil descriptions with their corresponding {sup 226}Ra concentrations, comes from geological cores drilled by geotechnical consultants with gamma spectrometry analysis performed by high resolution gamma spectroscopy. Concentration; of {sup 226}Ra generally increase with depth. These cores are usually terminated at 20 feet deep, with some cores being shallower than this due to hitting bedrock or encountering the water table. These frequency distributions give the core-logging geologist an approximate concentration of {sup 226}Ra based on the description of the soil. Since the correlation of {sup 226}Ra and soil descriptions can be used as a tool in assigning indoor radon potential, this study is of importance to land managers, contractors, developers, and regulating agencies who are attempting to place standards on tracts of land with {sup 226}Ra concentration used as a criterion.

  6. Audit Letter Report: OAS-RA-L-11-05 | Department of Energy

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

    1-05 Audit Letter Report: OAS-RA-L-11-05 March 8, 2011 Recovery Act Funded Projects at the ... Topic: Science & Innovation Audit Letter Report: OAS-RA-L-11-05 (104.28 KB) More Documents ...

  7. Ab initio molecular dynamics simulations of short-range order in Zr50Cu45Al5 and Cu50Zr45Al5 metallic glasses

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

    Huang, Yuxiang; Huang, Li; Wang, C. Z.; Kramer, M. J.; Ho, K. M.

    2016-02-01

    In this study, comparative analysis between Zr-rich Zr50Cu45Al5 and Cu-rich Cu50Zr45Al5 metallic glasses (MGs) is extensively performed to locate the key structural motifs accounting for their difference of glass forming ability. Here we adopt ab initio molecular dynamics simulations to investigate the local atomic structures of Zr50Cu45Al5 and Cu50Zr45Al5 MGs. A high content of icosahedral-related (full and distorted) orders was found in both samples, while in the Zr-rich MG full icosahedrons <0,0,12,0> is dominant, and in the Cu-rich one the distorted icosahedral orders, especially <0,2,8,2> and <0,2,8,1>, are prominent. And the <0,2,8,2> polyhedra in Cu50Zr45Al5 MG mainly originate from Al-centeredmore » clusters, while the <0,0,12,0> in Zr50Cu45Al5 derives from both Cu-centered clusters and Al-centered clusters. These difference may be ascribed to the atomic size difference and chemical property between Cu and Zr atoms. The relatively large size of Zr and large negative heat of mixing between Zr and Al atoms, enhancing the packing density and stability of metallic glass system, may be responsible for the higher glass forming ability of Zr50Cu45Al5.« less

  8. Ab initio molecular dynamics simulations of short-range order in Zr50Cu45Al5 and Cu50Zr45Al5 metallic glasses

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

    Huang, Yuxiang; Huang, Li; Wang, C. Z.; Kramer, M. J.; Ho, K. M.

    2016-02-01

    Comparative analysis between Zr-rich Zr50Cu45Al5 and Cu-rich Cu50Zr45Al5 metallic glasses (MGs) is extensively performed to locate the key structural motifs accounting for their difference of glass forming ability. Here we adopt ab initio molecular dynamics simulations to investigate the local atomic structures of Zr50Cu45Al5 and Cu50Zr45Al5 MGs. A high content of icosahedral-related (full and distorted) orders was found in both samples, while in the Zr-rich MG full icosahedrons < 0,0,12,0 > is dominant, and in the Cu-rich one the distorted icosahedral orders, especially < 0,2,8,2 > and < 0,2,8,1 >, are prominent. And the < 0,2,8,2 > polyhedra in Cu50Zr45Al5more » MG mainly originate from Al-centered clusters, while the < 0,0,12,0 > in Zr50Cu45Al5 derives from both Cu-centered clusters and Al-centered clusters. These difference may be ascribed to the atomic size difference and chemical property between Cu and Zr atoms. Lastly, the relatively large size of Zr and large negative heat of mixing between Zr and Al atoms, enhancing the packing density and stability of metallic glass system, may be responsible for the higher glass forming ability of Zr50Cu45Al5.« less

  9. Hadron Physics in BaBar

    SciTech Connect (OSTI)

    Lafferty, G.D.; /Manchester U.

    2005-08-29

    Some recent results in hadron physics from the BaBar experiment are discussed. In particular, the observation of two new charmed states, the D*{sub sJ}{sup +}(2317) and the D*{sub sJ}{sup +}(2457), is described, and results are presented on the first measurement of the rare decay mode of the B meson, B{sup 0} {pi}{sup 0}{pi}{sup 0}.

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

    SciTech Connect (OSTI)

    Rojas, J. V.; Woodward, J. D.; Chen, N.; Rondinone, A. J.; Castano, C. H.; Mirzadeh, S.

    2015-03-19

    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.

  11. Pygmy dipole strength in {sup 90}Zr

    SciTech Connect (OSTI)

    Schwengner, R.; Rusev, G.; Benouaret, N.; Beyer, R.; Erhard, M.; Junghans, A. R.; Klug, J.; Kosev, K.; Nair, C.; Schilling, K. D.; Wagner, A.; Tsoneva, N.; Grosse, E.; Lenske, H.

    2008-12-15

    The dipole response of the N=50 nucleus {sup 90}Zr was studied in photon-scattering experiments at the electron linear accelerator ELBE with bremsstrahlung produced at kinetic electron energies of 7.9, 9.0, and 13.2 MeV. We identified 189 levels up to an excitation energy of 12.9 MeV. Statistical methods were applied to estimate intensities of inelastic transitions and to correct the intensities of the ground-state transitions for their branching ratios. In this way we derived the photoabsorption cross section up to the neutron-separation energy. This cross section matches well the photoabsorption cross section obtained from ({gamma}, n) data and thus provides information about the extension of the dipole-strength distribution toward energies below the neutron-separation energy. An enhancement of E1 strength has been found in the range of 6 to 11 MeV. Calculations within the framework of the quasiparticle-phonon model ascribe this strength to a vibration of the excessive neutrons against the N=Z neutron-proton core, giving rise to a pygmy dipole resonance.

  12. List of Topics for Interagency Performance & Risk Assessment Community of Practice (P&RA CoP) Discussion

    Office of Energy Efficiency and Renewable Energy (EERE)

    List of Topics for Interagency Performance & Risk Assessment Community of Practice (P&RA CoP) Discussion

  13. Interagency Performance and Risk Assessment Community of Practice (P&RA

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

    CoP) Charter | Department of Energy Interagency Performance and Risk Assessment Community of Practice (P&RA CoP) Charter Interagency Performance and Risk Assessment Community of Practice (P&RA CoP) Charter Charter for the Interagency Performance and Risk Assessment Community of Practice (P&RA CoP) whose goal is to foster exchange of information regarding preparation of P&RAs across agencies and practitioners; enhance consistency in the preparation of P&RAs across the

  14. DRAFT Letter, PW 1/3/6 RD/RA Work Plan 1/19/16

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

    Letter, PW 1/3/6 RD/RA Work Plan 1/19/16 RAP Committee: Draft Letter: Remedial Design/Remedial Action (RD/RA) Work Plan for the 200-CW-5, 200- PW-1, PW-3, PW-6 Operable Units, DOE/RL-2015-23 (Draft B). Page 1 of 1 Draft HAB Letter: Remedial Design/Remedial Action (RD/RA) Work Plan for the 200- CW-5, 200-PW-1, PW-3, PW-6 Operable Units, DOE/RL-2015-23 (Draft B). Issue Managers: Engstrom, Hudson, Niles, Cimon, Mattson To: Stacy and Dennis Cc: Ecology and DOE HQ (Monica), Bertrand Recognizing that

  15. Microsoft Word - A10RA010 Report Cover 12-6-10

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

    Audits and Inspections Audit Report Audit of Environmental Cleanup Projects Funded by the Recovery Act at the Y-12 National Security Complex OAS-RA-L-11-02 December 2010 DOE F 1325.8 (08-93) United States Government Department of Energy Memorandum DATE: December 20, 2010 Audit Report Number: OAS-RA-L-11-02 REPLY TO ATTN OF: IG-32 (A10RA010) SUBJECT: Audit Report on "Environmental Cleanup Projects Funded by the Recovery Act at the Y-12 National Security Complex" TO: Manager, Y-12 Site

  16. SeeBA Energiesysteme GmbH | Open Energy Information

    Open Energy Info (EERE)

    search Name: SeeBA Energiesysteme GmbH Place: Stemwede, Germany Zip: 32351 Sector: Wind energy Product: Wind energy project developer, from planning through to implementation...

  17. Abnormal thermal conductivity in tetragonal tungsten bronze Ba...

    Office of Scientific and Technical Information (OSTI)

    temperature interval. Substitution of Sr for Ba brings about a significant decrease in thermal conductivity at x???3 accompanied by development of a low-temperature...

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

    Office of Scientific and Technical Information (OSTI)

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

  19. 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 March 21, 2013 The Department of Energy's Industrial Carbon Capture and Storage Program Funded by the American Recovery and Reinvestment Act The ...

  20. 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...

  1. Audit Report: OAS-RA-L-11-06 | Department of Energy

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

    6 Audit Report: OAS-RA-L-11-06 April 1, 2011 Department's Management of Cloud Computing Services Cloud computing enables convenient, on-demand access to shared computing resources...

  2. Audit Report: OAS-RA-L-13-01 | Department of Energy

    Energy Savers [EERE]

    Audit Report: OAS-RA-L-13-01 November 1, 2012 Implementation of the Department of Energy's Concentrating Solar Power Program The Department of Energy's (Department) Office of ...

  3. Examination Report: OAS-RA-13-09 | Department of Energy

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

    Examination Report: OAS-RA-13-09 February 19, 2013 North Carolina State Energy Office - ... The North Carolina State Energy Office's (Agency) received a 20.9 million competitive ...

  4. Biosketches of Speakers- P&RA CoP December 2014 Technical Exchange Meeting

    Office of Energy Efficiency and Renewable Energy (EERE)

    Bio-sketches of Speakers from the Performance & Risk Assessment Community of Practice (P&RA) Technical Exchange Meeting held in Las Vegas, Nevada on December 11 & 12, 2014.

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

    Energy Savers [EERE]

    Examination Report: OAS-RA-13-13 February 21, 2013 Texas State Energy Conservation Office ... The Texas State Energy Conservation Office (Agency) received a 45.6 million grant award ...

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

    Office of Environmental Management (EM)

    Examination Report: OAS-RA-13-02 Examination Report: OAS-RA-13-02 October 9, 2012 County of Los Angeles - Energy Efficiency and Conservation Block Grant Program Funds Provided by the American Recovery and Reinvestment Act of 2009 As part of the American Recovery and Reinvestment Act of 2009 (Recovery Act), the Energy Efficiency and Conservation Block Grant (EECBG) Program received $3.2 billion to develop, promote, implement and manage energy efficiency and conservation projects and programs

  7. EXAMINATION REPORT: OAS-RA-13-27 | Department of Energy

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

    EXAMINATION REPORT: OAS-RA-13-27 EXAMINATION REPORT: OAS-RA-13-27 July 15, 2013 Commonwealth of Puerto Rico Energy Affairs Administration - Energy Efficiency and Conservation Block Grant Program Funds Provided by the American Recovery and Reinvestment Act of 2009 As part of the American Recovery and Reinvestment Act of 2009 (Recovery Act), the Energy Efficiency and Conservation Block Grant (EECBG) Program received $3.2 billion to develop, promote, implement and manage energy efficiency and

  8. On the Verge of One Petabyte - the Story Behind the BaBar Database...

    Office of Scientific and Technical Information (OSTI)

    the Story Behind the BaBar Database System Citation Details In-Document Search Title: On the Verge of One Petabyte - the Story Behind the BaBar Database System The BaBar database ...

  9. Unitarity Triangle Angle Measurements at BaBar

    SciTech Connect (OSTI)

    Latham, Thomas E.; /SLAC

    2005-06-30

    We present recent results of measurements of the Unitarity Triangle angles alpha, beta and gamma made with the BaBar detector at the PEP-II asymmetric B factory. We present recent results of measurements of the Unitarity Triangle angles alpha, beta and gamma made with the BaBar detector at the PEP-II asymmetric B factory.

  10. 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 UMo 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 AlSi 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 AlSi alloy, an increase in the overall rate of diffusional interaction was observed; however, the diffusional interaction of Zr in contact with multicomponent AA6061 with 0.40.8 wt.% Si was most rapid.

  11. Structure-Curie temperature relationships in BaTiO 3 -based ferroelect...

    Office of Scientific and Technical Information (OSTI)

    ferroelectric perovskites: Anomalous behavior of ( Ba , Cd ) TiO 3 from DFT, ... ferroelectric perovskites: Anomalous behavior of ( Ba , Cd ) TiO 3 from DFT, ...

  12. Innovative methodology for the synthesis of Ba-M hexaferrite BaFe{sub 12}O{sub 19} nanoparticles

    SciTech Connect (OSTI)

    Ahmed, M.A.; Helmy, N.; El-Dek, S.I.

    2013-09-01

    Graphical abstract: Transmission electron microscope images for the BaFe12O19. - Highlights: BaFe{sub 12}O{sub 19}nanoparticles were prepared in single-phase from organometallic precursors. BaFe{sub 12}O{sub 19} possesses small size 65 nm, H{sub C} = 3695 Oe and M{sub s} = 58 emu/g. This method of preparation could be extended in the synthesis of other metal oxide nanoparticles. - Abstract: In this piece of work, high quality and homogeneity, barium hexaferrite (BaM) BaFe{sub 12}O{sub 19} nanoparticles were prepared from organometallic precursors for the 1st time. This method is based on the formation of supramolecular crystal structure of Ba[Fe(H{sub 3}NCH{sub 2}CH{sub 2}NH{sub 3})]Cl{sub 7}8H{sub 2}O. The crystal structure, morphology and magnetic properties of BaFe{sub 12}O{sub 19} at two different annealing temperatures namely 1000 C and 1200 C were investigated using X-ray diffraction, transmission electron microscope TEM and vibrating sample magnetometry (VSM). The results show that monophasic nanoparticles of hexaferrites were obtained. Nanoparticles of crystallite size 4050 nm distinguished by narrow distribution and excellent homogeneity were obtained with superior magnetic properties which suggested single-domain particles of Ba-M hexaferrite.

  13. Crystal Structure and Thermodynamic Stability of Ba/Ti-Substituted Pollucites for Radioactive Cs/Ba Immobilization

    SciTech Connect (OSTI)

    Xu, Hongwu; Chavez, Manuel E.; Mitchell, Jeremy N.; Garino, Terry J.; Schwarz, Haiqing L.; Rodriguez, Mark A.; Rademacher, David X.; Nenoff, Tina Maria

    2015-04-23

    An analogue of the mineral pollucite (CsAlSi2O6), CsTiSi2O6.5 has a potential host phase for radioactive Cs. However, as 137Cs and 135Cs transmute to 137Ba and 135Ba, respectively, through the beta decay, it is essential to study the structure and stability of this phase upon Cs → Ba substitution. In this work, two series of Ba/Ti-substituted samples, CsxBa(1-x)/2TiSi2O6.5 and CsxBa1-xTiSi2O7-0.5x, (x = 0.9 and 0.7), were synthesized by high-temperature crystallization from their respective precursors. Synchrotron X-ray diffraction and Rietveld analysis reveal that while CsxBa(1-x)/2TiSi2O6.5 samples are phase-pure, CsxBa1-xTiSi2O7-0.5x samples contain Cs3x/(2+x)Ba(1-x)/(2+x)TiSi2O6.5 pollucites (i.e., also two-Cs-to-one-Ba substitution) and a secondary phase, fresnoite (Ba2TiSi2O8). Thus, the CsxBa1-xTiSi2O7-0.5x series is energetically less favorable than CsxBa(1-x)/2TiSi2O6.5. To study the stability systematics of CsxBa(1-x)/2TiSi2O6.5 pollucites, high-temperature calorimetric experiments were performed at 973 K with or without the lead borate solvent. Enthalpies of formation from the constituent oxides (and elements) have thus been derived. Our results show that with increasing Ba/(Cs + Ba) ratio, the thermodynamic stability of these phases decreases with respect to their component oxides. Hence, from the energetic viewpoint, continued Cs → Ba transmutation tends to destabilize the parent silicotitanate pollucite structure. However, the Ba-substituted pollucite co-forms with fresnoite (which incorporates the excess Ba

  14. 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.

  15. Pressure and tension effects on mechanical properties of ZrAl{sub 2}

    SciTech Connect (OSTI)

    Zhang, Pinliang; Tang, Xiuzhang; Meng, Fanchen; Gong, Zizheng; Ji, Guangfu; Yang, Jinke

    2014-11-15

    Structural, elastic, thermodynamic of ZrAl{sub 2} under pressure, ideal strength and deformation mode under tension are investigated by the first-principles method. The calculated structural parameters at zero pressure are in consistent with experiments. Under pressure, elastic constants and their pressure dependence are obtained using the static finite strain technique. ZrAl{sub 2} exhibits lower elastic anisotropy. The linear thermal expansion coefficient shows greater effects of temperature at lower pressure. The ideal tensile have been investigated by stress–strain calculations. Finally, the microscopic mechanism that determines the structural stability is studied using the results of electronic structure calculations. We propose that the weakening of Zr-Zr leads to the significant change of stress–strain curve at strain ∼0.27, and the breaking of Zr{sub 2}-Zr{sub 3} leads to the structural instability of ZrAl{sub 2} under large tensile strains.

  16. 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

  17. Ba2TeO: A new layered oxytelluride

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

    Besara, T.; Ramirez, D.; Sun, J.; Whalen, J. B.; Tokumoto, T. D.; McGill, S. A.; Singh, D. J.; Siegrist, T.

    2015-02-01

    For single crystals of the new semiconducting oxytelluride phase, Ba2TeO, we synthesized from barium oxide powder and elemental tellurium in a molten barium metal flux. Ba2TeO crystallizes in tetragonal symmetry with space group P4/nmm (#129), a=5.0337(1) Å, c=9.9437(4) Å, Z=2. The crystals were characterized by single crystal x-ray diffraction, heat capacity and optical measurements. Moreover, the optical measurements along with electronic band structure calculations indicate semiconductor behavior with a band gap of 2.93 eV. Resistivity measurements show that Ba2TeO is highly insulating.

  18. Fuel-cladding interaction layers in irradiated U-ZR and U-PU-ZR fuel elements.

    SciTech Connect (OSTI)

    Keiser, D. D.

    2006-01-23

    Argonne National Laboratory is developing an electrometallurgical treatment for spent nuclear fuels. The initial demonstration of this process is being conducted on U-Zr and U-Pu-Zr alloy fuel elements irradiated in the Experimental Breeder Reactor-II (EBR-II). The electrometallurgical treatment process extracts usable uranium from irradiated fuel elements and places residual fission products, actinides, process Zr, and cladding hulls (small segments of tubing) into two waste forms--a ceramic and a metal alloy. The metal waste form will contain the cladding hulls, Zr, and noble metal fission products, and it will be disposed of in a geologic repository. As a result, the expected composition of the waste form will need to be well understood. This report deals with the condition of the cladding, which will make up a large fraction of the metal waste form, after irradiation in EBR-II and before insertion into the electrorefiner. Specifically, it looks at layers that can be found on the inner surface of the cladding due to in-reactor interactions between the alloy fuel and the stainless steel cladding that occurs after the fuel has swelled and contacted the cladding. Many detailed examinations of fuel elements irradiated in EBR-II have been completed and are discussed in the context of interaction layer formation in irradiated cladding. The composition and thickness of the developed interaction layers are identified, along with the irradiation conditions, cladding type, and axial location on fuel elements where the thickest interaction layers can be expected to develop. It has been found that the largest interaction zones are observed at combined high power and high temperature regions of fuel elements and for fuel elements with U-Pu-Zr alloy fuel and D9 stainless steel cladding. The most prevalent, non-cladding constituent observed in the developed interaction layers are the lanthanide fission products.

  19. Using Pb-210/Ra-226 disequilibria for sablefish, Anoplopoma fimbria, age validation

    SciTech Connect (OSTI)

    Kastelle, C.R.; Kimura, D.K. ); Nevissi, A.E.; Gunderson, D.R. )

    1994-04-01

    Age determination of sablefish (Anoplopoma fimbria) is typically done by counting growth zones on the burnt cross-section of the otolith. The break-and-burn method of age determination is difficult to apply to sablefish. Therefore, we applied a relatively new method of fish age validation, using the disequilibrium of Pb-210/Ra-226 in the otoliths. This method of validation complements previous methods which used oxytetracycline (OTC) marking to validate incremental growth in sablefish otoliths. The Pb-210/Ra-226 disequilibria generally confirmed the ageing criteria used to interpret the otolith's burnt cross-section.

  20. Special Report: IG-RA-09-02 | Department of Energy

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

    RA-09-02 Special Report: IG-RA-09-02 March 30, 2009 The Department of Energy's Acquisition Workforce and its Impact on Implementation of the American Recovery and Reinvestment Act of 2009 Signed by the President on February 17, 2009, the American Recovery and Reinvestment Act of 2009 (Recovery Act) seeks to strengthen the U.S. economy through the creation of new jobs, aiding State and local governments with budget shortfalls, and investing in the long-term health of the Nation's economic

  1. Symmetry-Breaking Orbital Anisotropy Observed for Detwinned Ba...

    Office of Scientific and Technical Information (OSTI)

    Symmetry-Breaking Orbital Anisotropy Observed for Detwinned Ba(Fe (1-X) Co (X) ) (2) As (2) Above the Spin Density Wave Transition Citation Details In-Document Search Title: ...

  2. Transition probabilities in the X(5) candidate {sup 122}Ba

    SciTech Connect (OSTI)

    Bizzeti, P. G.; Giannatiempo, A.; Melon, B.; Perego, A.; Sona, P.; Bizzeti-Sona, A. M.; Tonev, D.; Ur, C. A.; Bazzacco, D.; Farnea, E.; Marginean, R.; Menegazzo, R.; Rossi Alvarez, C.; Dewald, A.; Fransen, C.; Michelagnoli, C.; Lenzi, S.; Lunardi, S.; Mengoni, D.; Nespolo, M.

    2010-11-15

    To investigate the possible X(5) character of {sup 122}Ba, suggested by the ground-state band energy pattern, the lifetimes of the lowest yrast states of {sup 122}Ba have been measured, via the recoil distance Doppler-shift method. The relevant levels have been populated by using the {sup 108}Cd({sup 16}O,2n){sup 122}Ba and the {sup 112}Sn({sup 13}C,3n){sup 122}Ba reactions. The B(E2) values deduced in the present work are compared to the predictions of the X(5) model and to calculations performed in the framework of the IBA-1 and IBA-2 models.

  3. Leptonic B Decays at BaBar

    SciTech Connect (OSTI)

    Monorchio, Diego; /INFN, Naples /Naples U.

    2011-09-13

    The authors will present the most recent results on leptonic B decays B{sup {+-}(0)} {yields} K*{sup {+-}(0)} {nu}{bar {nu}} and B{sup {+-}} {yields} {mu}{sup {+-}}{nu}, based on the data collected by the BaBar detector at PEP-II, an asymmetric e{sup +}e{sup -} collider at the center of mass energy of the {Upsilon}(4S) resonance. Rare B decays have always been a standard probe for New Physics (NP) searches. The very low Standard Model (SM) rate of these decays often make them unaccessible with the present experimental datasets, unless NP effects enhance the rate up to the current experimental sensitivity. Moreover, as NP effects can modify the decay kinematic, particular attention must be payed in order to perform a model independent analysis. A B-Factory provides an unique environment where to investigate these processes. The high number of B{bar B} pairs produced by a B-Factory often allows to approach the needed experimental sensitivity. Moreover, the clean environment and the closed kinematic of the initial state enable to obtaining a very pure sample where to look for these decays.

  4. Leptonic B Decays at BaBar

    SciTech Connect (OSTI)

    Baracchini, Elisabetta; /Rome U. /INFN, Rome

    2011-11-10

    We will present the most recent results on leptonic B decays B{sup {+-}(0)} {yields} K*{sup {+-}(0)}{nu}{bar {nu}} and B{sup {+-}} {yields} {mu}{sup {+-}}{nu}, based on the data collected by the BaBar detector at PEP-II, an asymmetric e{sup +}e{sup -} collider at the center of mass energy of the {Upsilon}(4S) resonance. Rare B decays have always been a standard probe for New Physics (NP) searches. The very low Standard Model (SM) rate of these decays often make them unaccessible with the present experimental datasets, unless NP effects enhance the rate up to the current experimental sensitivity. Moreover, as NP effects can modify the decay kinematic, particular attention must be paid in order to perform a model independent analysis. A B-Factory provides an unique environment to investigate these processes. The high number of B{bar B} pairs produced by a B-Factory often allows to approach the needed experimental sensitivity. Moreover, the clean environment and the closed kinematic of the initial state enable to obtaining a very pure sample where to look for these decays.

  5. UNITED STATE% ENGINEER OFFICE I" RaCLI MANHATTAN D' ISTRICT

    Office of Legacy Management (LM)

    w-1 - ,.. P..*e ,e.arzUE.m -JuTm-&a- . . . UNITED STATE% ENGINEER OFFICE I" RaCLI MANHATTAN D' ISTRICT RLFSR TO ; I. 0. eox a ,. STATJON J N E W YORK, N. Y. tr.et h % ...

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

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

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

    2014-11-20

    Here, 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. Moreover, 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.

  7. 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.

  8. Density-functional study of the La2Zr207 (001) and (011) surfaces...

    Office of Scientific and Technical Information (OSTI)

    Language: English Subject: 30 DIRECT ENERGY CONVERSION; 36 MATERIALS SCIENCE; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS La2Zr207 surface Word Cloud More Like This Full ...

  9. QUANTIFYING COMPOSITIONAL HOMOGENEITY IN Pb(ZrTi)O3 USING ATOM...

    Office of Scientific and Technical Information (OSTI)

    Title: QUANTIFYING COMPOSITIONAL HOMOGENEITY IN Pb(ZrTi)O3 USING ATOM PROBE TOMOGRAPHY. Abstract not provided. Authors: Ihlefeld, Jon F. ; Kotula, Paul Gabriel ; Brennecka, ...

  10. 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.

  11. 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.

  12. Current (1984) status of the study of /sup 226/Ra and /sup 228/Ra in humans at the Center for Human Radiobiology

    SciTech Connect (OSTI)

    Rundo, J.; Keane, A.T.; Lucas, H.F.; Schlenker, R.A.; Stebbings, J.H.; Stehney, A.F.

    1984-01-01

    The Center for Human Radiobiology has identified 5784 persons by name and type of exposure to /sup 226/Ra and /sup 228/Ra. Included are 4863 dial painters (mostly women) and non-laboratory employees of the radium dial industry, 410 laboratory workers, 399 persons who received radium for supposed therapeutic effects, and 112 in other categories. Body contents of radium have been measured in 1916 of the dial workers and about one-half of the subjects in the other groups. Bone sarcomas, carcinomas of the paranasal sinuses and mastoids, and deterioration of skeletal tissue are still the only effects unequivocally attributable to internal radium. Excess leukemias have not been observed and other malignancies, if in excess, appear more likely to be related to external gamma radiation or radon than to internal radium. Positive correlations with radium burdens have been found for the incidence of benign exostoses among subjects exposed to radium before age 18 and for shortened latency of ocular cataracts. 26 references, 3 figures, 5 tables.

  13. 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

    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 μm 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.

  14. Processing of R-Ba-Cu-O superconductors

    SciTech Connect (OSTI)

    Wu, H.

    1998-02-23

    Precipitation processes were developed to introduce second phases as flux pinning centers in Gd-Ba-Cu-O and Nd-Ba-Cu-O superconductors. In Gd-Ba-Cu-O, precipitation is caused by the decrease of the upper solubility limit of Gd{sub 1+x}Ba{sub 2{minus}x}Cu{sub 3}O{sub 7} solid solution (Gd123ss) in low oxygen partial pressure. Processing of supersaturated Gd{sub 1.2}Ba{sub 1.8}Cu{sub 3}O{sub 7} in low oxygen partial pressure can produce dispersed second phases. Gd211 is formed as a separate phase while extensive Gd124 type stacking fault is formed instead of a separate CuO phase. As a result of the precipitation reaction, the transition temperature and critical current density are increased. In Nd-Ba-Cu-O, precipitation is caused by the decrease of the lower solubility limit of Nd{sub 1+x}Ba{sub 2{minus}x}Cu{sub 3}O{sub 7} solid solution (Nd123ss) in oxygen. DTA results reveal the relative stability of Nd123ss in different oxygen partial pressures. In 1 bar oxygen partial pressure, Nd123ss with x = 0.1 is the most stable phase. In lower oxygen partial pressures, the most stable composition shifts towards the stoichiometric composition. The relative stability changes faster with decreasing oxygen partial pressure. Therefore, processing in oxygen and air tends to produce broad superconducting transitions but sharp transitions can be achieved in 0.01 bar and 0.001 bar oxygen partial pressures. While the lower solubility limits in 0.01 bar and 0.001 bar oxygen partial pressures remain at x = 0.00, the solubility limits in oxygen and air show a narrowing with decreasing temperature. Because of the narrowing of the solubility range in oxygen, oxygen annealing of Nd123 initially processed in low oxygen partial pressures will result in precipitation of second phases. The equilibrium second phase is BaCuO{sub 2} for temperature above 608 C, and at lower temperatures the equilibrium second phases are Ba{sub 2}CuO{sub 3.3} and Ba{sub 2}Cu{sub 3}O{sub 5+y}. However, annealing at

  15. Radiative strength functions for dipole transitions in {sup 90}Zr

    SciTech Connect (OSTI)

    Fedorets, I. D. Ratkevich, S. S.

    2013-01-15

    Partial cross sections for the (p, {gamma}) reaction on the {sup 89}Y nucleus that were measured previously at proton energies between 2.17 and 5.00 MeV and which were averaged over resonances were used to determine the absolute values and the energy distribution of the strength of dipole transitions from compound-nucleus states to low-lying levels of the {sup 90}Zr nucleus. The data obtained in this way were compared with the predictions of various models.

  16. 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.

  17. 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.

  18. Observation of excited states in /sup 128/Ba

    SciTech Connect (OSTI)

    Zhao Zhi-zheng; Guo Ying-xiang; Pan Zong-you; Xiao Jian-min; Lei Xiang-guo; Liu Hong-ye; Sun Xi-jun

    1987-01-01

    Excited states in /sup 128/Ba have been investigated via the /sup 120/Sn (/sup 12/C, 4n..gamma..) /sup 128/Ba reaction by means of in-beam gamma spectroscopy. A 12/sup +/ state other than the previously reported one is observed according to the properties of the 935.0 keV ..gamma..-ray. It does not belong to the ground-state band. Two new interband transitions, 224.8 keV and 632.7 keV, are observed and assigned to sidefeeding between the negative-parity band and ground-state band.

  19. The Hydrogen Energy California Project, OAS-RA-13-22

    Energy Savers [EERE]

    U.S. Department of Energy Office of Inspector General Office of Audits and Inspections Audit Report The Hydrogen Energy California Project OAS-RA-13-22 June 2013 Department of Energy Washington, DC 20585 June 6, 2013 MEMORANDUM FOR THE ACTING DEPUTYASSISTANT SECRETARY FOR CLEAN COAL DIRECTOR FOR POLICY, OFFICE OF ACQUISITION AND PROJECT MANAGEMENT FROM: David Sedillo Director, Western Audits Division Office of Inspector General SUBJECT: INFORMATION: Audit Report on "The Hydrogen Energy

  20. The Department of Energy's Solid-State Lighting Program, OAS-RA-L-13-03

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

    Solid- State Lighting Program OAS-RA-L-13-03 February 2013 Department of Energy Washington, DC 20585 February 28, 2013 MEMORANDUM FOR THE DIRECTOR, NATIONAL ENERGY TECHNOLOGY LABORATORY FROM: Jack Rouch, Director Central Audits Division Office of Inspector General SUBJECT: INFORMATION: Audit Report on "The Department of Energy's Solid-State Lighting Program" BACKGROUND The Department of Energy's (Department) Office of Energy Efficiency and Renewable Energy established the Solid-State

  1. Audit Report: OAS-RA-10-08 | Department of Energy

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

    8 Audit Report: OAS-RA-10-08 April 27, 2010 The Department of Energy's Program to Assist Federal Buyers in the Purchasing of Energy Efficient Products The American Recovery and Reinvestment Act of 2009 (Recovery Act) established a series of energy-related goals, one of which was to make Federal facilities more energy efficient. The Department of Energy (Department) plays an integral part in this process. The Department's Federal Energy Management Program (FEMP), established in 1973, helps

  2. Audit Report: OAS-RA-11-03 | Department of Energy

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

    3 Audit Report: OAS-RA-11-03 November 30, 2010 The Department of Energy's Weatherization Assistance Program under the American Recovery and Reinvestment Act for the City of Phoenix - Agreed-Upon Procedures The attached report presents the results of an agreed-upon procedures review of the Department of Energy's (Department) Weatherization Assistance Program in the City of Phoenix, Arizona, under the American Recovery and Reinvestment Act of 2009 (Recovery Act). The Office of Inspector General

  3. Audit Report: OAS-RA-11-10 | Department of Energy

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

    0 Audit Report: OAS-RA-11-10 July 28, 2011 The Department of Energy's American Recovery and Reinvestment Act - California State Energy Program The Department of Energy's Office of Energy Efficiency and Renewable Energy (EERE) provides grants to states, territories and the District of Columbia (states) through the State Energy Program (SEP). Federal funding, based on a grant formula that considers the population and energy consumption in each state, amounted to $25 million for Fiscal Year (FY)

  4. Audit Report: OAS-RA-12-02 | Department of Energy

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

    2-02 Audit Report: OAS-RA-12-02 November 9, 2011 The State of Nevada's Implementation of the Energy Efficiency and Conservation Block Grant Program Under the American Recovery and Reinvestment Act of 2009 (Recovery Act), the Department of Energy (Department) received $3.2 billion to fund, for the first time, the Energy Efficiency and Conservation Block Grant Program (EECBG Program). The EECBG Program provides grants to U.S. local governments, states, territories and Indian tribes to fund

  5. Audit Report: OAS-RA-L-11-11 | Department of Energy

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

    1 Audit Report: OAS-RA-L-11-11 September 23, 2011 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 Under the American Recovery and Reinvestment Act of 2009 (Recovery Act), the Department of Energy's (Department) Energy Efficiency and Conservation Block Grant Program (Program) received $3.2 billion in funding to help U.S. cities, counties and states to develop, promote, implement

  6. Examination Report: OAS-RA-11-18 | Department of Energy

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

    8 Examination Report: OAS-RA-11-18 September 29, 2011 Community Action Partnership of the Greater Dayton Area - Weatherization Assistance Program Funds Provided by the American Recovery and Reinvestment Act of 2009 Under the American Recovery and Reinvestment Act of 2009 (Recovery Act), the Department of Energy's (Department) Weatherization Assistance Program (Weatherization Program) received $5 billion to increase the energy efficiency of dwellings owned or occupied by low-income persons.

  7. Examination Report: OAS-RA-11-19 | Department of Energy

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

    9 Examination Report: OAS-RA-11-19 September 29, 2011 Cuyahoga County of Ohio Department of Development - Weatherization Assistance Program Funds Provided by the American Recovery and Reinvestment Act of 2009 Under the American Recovery and Reinvestment Act of 2009 (Recovery Act), the Department of Energy's (Department) Weatherization Assistance Program (Weatherization Program) received $5 billion to increase the energy efficiency of dwellings owned or occupied by low-income persons.

  8. Examination Report: OAS-RA-11-20 | Department of Energy

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

    0 Examination Report: OAS-RA-11-20 September 30, 2011 People's Equal Action and Community Effort, Inc. -Weatherization Assistance Program Funds Provided by the American Recovery and Reinvestment Act of 2009 The attached report presents the results of an examination of the People's Equal Action and Community Effort, Inc. (PEACE), Weatherization Assistance Program (Weatherization Program) under the American Recovery and Reinvestment Act of 2009 (Recovery Act). The Office of Inspector General (OIG)

  9. Examination Report: OAS-RA-13-03 | Department of Energy

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

    3 Examination Report: OAS-RA-13-03 October 17, 2012 Community Action Partnership of Orange County - Weatherization Assistance Program Funds Provided by the American Recovery and Reinvestment Act of 2009 As part of the American Recovery and Reinvestment Act of 2009 (Recovery Act), the Weatherization Assistance Program (Weatherization Program) received $5 billion to reduce energy consumption for low-income households through energy efficient upgrades. The State of California received $186 million

  10. Examination Report: OAS-RA-13-11 | Department of Energy

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

    1 Examination Report: OAS-RA-13-11 February 19, 2013 Fresno County Economic Opportunities Commission Weatherization Assistance Program Funds Provided by the American Recovery and Reinvestment Act of 2009 As part of the American Recovery and Reinvestment Act of 2009 (Recovery Act) the Weatherization Assistance Program (Weatherization Program) received $5 billion to reduce energy consumption for low-income households through energy efficient upgrades. The State of California received $186 million

  11. Examination Report: OAS-RA-13-12 | Department of Energy

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

    2 Examination Report: OAS-RA-13-12 February 19, 2013 City of Los Angeles - Energy Efficiency and Conservation Block Grant Program Funds Provided by the American Recovery and Reinvestment Act of 2009 As part of the American Recovery and Reinvestment Act of 2009 (Recovery Act), the Energy Efficiency and Conservation Block Grant (EECBG) Program received $3.2 billion to develop, promote, implement and manage energy efficiency and conservation projects and programs designed to reduce fossil fuel

  12. Examination Report: OAS-RA-13-14 | Department of Energy

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

    4 Examination Report: OAS-RA-13-14 February 28, 2013 Connecticut Department of Energy and Environmental Protection Energy Efficiency and Conservation Block Grant Program Funds Provided by the American Recovery and Reinvestment Act of 2009 As part of the American Recovery and Reinvestment Act of 2009 (Recovery Act), the Energy Efficiency and Conservation Block Grant (EECBG) Program received $3.2 billion to develop, promote, implement and manage energy efficiency and conservation projects and

  13. Management Alert: OAS-RA-11-16 | Department of Energy

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

    1-16 Management Alert: OAS-RA-11-16 September 1, 2011 The Status of Energy Efficiency and Conservation Block Grant Recipients' Obligations Under the American Recovery and Reinvestment Act of 2009 (Recovery Act), the Department of Energy (Department) Energy Efficiency and Conservation Block Grant (EECBG) Program received $3.2 billion to improve energy efficiency and reduce energy use and fossil fuel emission. EECBG agreements have a maximum performance period of 36 months and, in support of the

  14. Special Report: OAS-RA-13-10 | Department of Energy

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

    13-10 Special Report: OAS-RA-13-10 February 8, 2013 The Department of Energy's Management of the Award of a $150 Million Recovery Act Grant to LG Chem Michigan Inc The Department of Energy's Vehicle Technologies Program was established to develop and deploy efficient and environmentally friendly highway transportation technologies to reduce the Nation's dependence on foreign oil and provide greater energy security. The Vehicle Technologies Program received $2.4 billion under the American

  15. Microsoft PowerPoint - P&RA CoP EPA optimization Biggs final 111215

    Office of Environmental Management (EM)

    Implementing Optimization in the Superfund Program __________________________________________________ For the Interagency Performance and Risk Assessment Community of Practice (P&RA CoP) November 12, 2015 Kirby Biggs National Optimization Program Coordinator Technology Integration and Information Branch Office of Superfund Remediation and Technology Integration Washington DC 20460 biggs.kirby@epa.gov . 703-823-3081 . www.cluin.org/optimization (Cleanup Horizon: 2004 - 2033) Source:

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

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

    7 Examination Report: OAS-RA-13-17 March 28, 2013 Community Action Partnership of San Bernardino County - Weatherization Assistance Program Funds Provided by the American Recovery and Reinvestment Act of 2009 As part of the American Recovery and Reinvestment Act of 2009 (Recovery Act), the Weatherization Assistance Program (Weatherization Program) received $5 billion to reduce energy consumption for low-income households through energy efficient upgrades. The State of California received $186

  17. Audit Report: OAS-RA-09-03 | Department of Energy

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

    09-03 Audit Report: OAS-RA-09-03 May 27, 2009 Department of Energy Efforts to Manage Information Technology Resources in an Energy-Efficient and Environmentally Responsible Manner Conservation as critical to the Nation's economic vitality; its goal of reducing dependence on foreign energy sources; and, related efforts to improve the environment. The Act highlights the significant use of various forms of energy in the Federal sector and promotes efforts to improve the energy efficiency of Federal

  18. Audit Report: OAS-RA-11-04 | Department of Energy

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

    4 Audit Report: OAS-RA-11-04 February 1, 2011 The Department of Energy's Weatherization Assistance Program under the American Recovery and Reinvestment Act for the Capital Area Community Action Agency - Agreed-Upon Procedures The attached report presents the results of an agreed-upon procedures review of the Department of Energy's (Department) Weatherization Assistance Program for the Capital Area Community Action Agency, located in Tallahassee, Florida under the American Recovery and

  19. Audit Report: OAS-RA-11-07 | Department of Energy

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

    7 Audit Report: OAS-RA-11-07 June 6, 2011 The Department of Energy's Weatherization Assistance Program Funded under the American Recovery and Reinvestment Act for the State of Wisconsin The Department of Energy's Weatherization Assistance Program (Weatherization Program) received $5 billion under the American Recovery and Reinvestment Act of 2009 (Recovery Act) to improve the energy efficiency of homes, multi-family rental units and mobile homes owned or occupied by low-income persons.

  20. Audit Report: OAS-RA-11-12 | Department of Energy

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

    2 Audit Report: OAS-RA-11-12 August 22, 2011 The Department of Energy's Weatherization Assistance Program under the American Recovery and Reinvestment Act in the State of Missouri The Department of Energy's (Department) Weatherization Assistance Program (Weatherization Program) received $5 billion under the American Recovery and Reinvestment Act of 2009 to improve the energy efficiency of the homes of low-income individuals, of which the State of Missouri received a 3-year Weatherization Program

  1. Audit Report: OAS-RA-11-14 | Department of Energy

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

    4 Audit Report: OAS-RA-11-14 August 25, 2011 The Department of Energy's Weatherization Assistance Program Funded under the American Recovery and Reinvestment Act for the Commonwealth of Virginia In May 2010, the Office of Inspector General (OIG) issued a Preliminary Audit Report on the effectiveness of the Commonwealth of Virginia's implementation of the American Recovery and Reinvestment Act of 2009 (Recovery Act) funded Weatherization Assistance Program (Weatherization Program). The report,

  2. Audit Report: OAS-RA-13-22 | Department of Energy

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

    2 Audit Report: OAS-RA-13-22 June 6, 2013 The Hydrogen Energy California Project Under the American Recovery and Reinvestment Act of 2009, the Department of Energy's (Department) Office of Fossil Energy received $3.4 billion to focus on the research, development and deployment of technologies to use coal more cleanly and efficiently. In September 2009, the Department approved a cooperative agreement award with a Government contribution of $308 million to Hydrogen Energy California, LLC (HECA) to

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

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

    31 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 years on Hydrogen and Fuel Cells Program activities implemented through various projects at Federal laboratories, universities, non-profit institutions, Government agencies and industry participants. The Department also provided an additional $42 million in American Recovery and Reinvestment Act of 2009 funding to

  4. Audit Report: OAS-RA-L-13-03 | Department of Energy

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

    3 Audit Report: OAS-RA-L-13-03 February 28, 2013 The Department of Energy's Solid-State Lighting Program The Department of Energy's (Department) Office of Energy Efficiency and Renewable Energy established the Solid-State Lighting Program to advance the development and market introduction of energy-efficient white-light sources for general illumination. The American Recovery and Reinvestment Act of 2009 appropriated more than $41 million to accelerate solid-state lighting research and

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

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

    Transportation Electrification Program OAS-RA-12-11 May 2012 Department of Energy Washington, DC 20585 May 10, 2012 MEMORANDUM FOR THE DEPUTY ASSISTANT SECRETARY FOR ENERGY EFFICIENCY FROM: Joanne Hill, Director Central Audits Division Office of Inspector General SUBJECT: INFORMATION: Special Report on "The Department of Energy's Transportation Electrification Program" INTRODUCTION The Department of Energy established the Transportation Electrification Program (Program) to demonstrate

  6. Study of the Decays of Charm Mesons With the BaBar Experiment...

    Office of Scientific and Technical Information (OSTI)

    Study of the Decays of Charm Mesons With the BaBar Experiment Citation Details In-Document Search Title: Study of the Decays of Charm Mesons With the BaBar Experiment You are ...

  7. Electric control of magnetism at the Fe/BaTiO3 interface (Journal...

    Office of Scientific and Technical Information (OSTI)

    Electric control of magnetism at the FeBaTiO3 interface Citation Details In-Document Search Title: Electric control of magnetism at the FeBaTiO3 interface Interfacial ...

  8. Optimizing Parallel Access to the BaBar Database System Using...

    Office of Scientific and Technical Information (OSTI)

    Optimizing Parallel Access to the BaBar Database System Using CORBA Servers Citation Details In-Document Search Title: Optimizing Parallel Access to the BaBar Database System Using ...

  9. Bottomonium Spectroscopy at BaBar and Belle (Conference) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    Bottomonium Spectroscopy at BaBar and Belle Citation Details In-Document Search Title: Bottomonium Spectroscopy at BaBar and Belle You are accessing a document from the ...

  10. Production of BaBar Skimmed Analysis Datasets Using the Grid...

    Office of Scientific and Technical Information (OSTI)

    Production of BaBar Skimmed Analysis Datasets Using the Grid Citation Details In-Document Search Title: Production of BaBar Skimmed Analysis Datasets Using the Grid You are ...

  11. Electric control of magnetism at the Fe/BaTiO3 interface (Journal...

    Office of Scientific and Technical Information (OSTI)

    Electric control of magnetism at the FeBaTiO3 interface Citation Details In-Document Search Title: Electric control of magnetism at the FeBaTiO3 interface You are accessing a ...

  12. Searches for Light New Physics at BaBar (Conference) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Search Results Conference: Searches for Light New Physics at BaBar Citation Details In-Document Search Title: Searches for Light New Physics at BaBar Authors: ...

  13. Structural phase transitions in BaPrO{sub 3}

    SciTech Connect (OSTI)

    Saines, Paul J.; Kennedy, Brendan J. Smith, Ronald I.

    2009-04-02

    The crystal structures adopted by BaPrO{sub 3} at and above ambient temperature have been examined using a combination of synchrotron X-ray and neutron diffraction. BaPrO{sub 3} has been established to undergo a series of phase transitions from Pbnmorthorhombic{yields}Ibmmorthorhombic{yields}R3-bar crhombohedral{yields}Pm3-barm cubic. BaPrO{sub 3} is the second A{sup 2+}B{sup 4+}O{sub 3} perovskite found to adopt rhombohedral symmetry in preference to the I4/mcm tetragonal structure. Analysis of the octahedral tilting through the rhombohedral to cubic phase transition indicates that this transformation is continuous and tricritical in nature. The tricritical behaviour of this transition is likely to be a result of the competition between tetragonal and rhombohedral structures to be the preferred phase, with the rhombohedral symmetry adopted by BaPrO{sub 3} being stabilised by the unusually large B-site cation.

  14. Hysteretic electrical transport in BaTiO{sub 3}/Ba{sub 1?x}Sr{sub x}TiO{sub 3}/Ge heterostructures

    SciTech Connect (OSTI)

    Ngai, J. H.; Kumah, D. P.; Walker, F. J.; Ahn, C. H.

    2014-02-10

    We present electrical transport measurements of heterostructures comprised of BaTiO{sub 3} and Ba{sub 1?x}Sr{sub x}TiO{sub 3} epitaxially grown on Ge. Sr alloying imparts compressive strain to the BaTiO{sub 3}, which enables the thermal expansion mismatch between BaTiO{sub 3} and Ge to be overcome to achieve c-axis oriented growth. The conduction bands of BaTiO{sub 3} and Ba{sub 1?x}Sr{sub x}TiO{sub 3} are nearly aligned with the conduction band of Ge, which facilitates electron transport. Electrical transport measurements through the dielectric stack exhibit rectifying behavior and hysteresis, where the latter is consistent with ferroelectric switching.

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

    SciTech Connect (OSTI)

    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. Boron atoms were found to be able to substitute cobalt atoms or occupy the “interruption” sites. First-principles calculations showed that the magnetocrystalline anisotropy 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. As a result, our calculations provide useful guidelines for further experimental optimization of the magnetic performances of these alloys.

  16. 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. Boron atoms were found to be able to substitute cobalt atoms or occupy the “interruption” sites. First-principles calculations showed that themore » magnetocrystalline anisotropy 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. As a result, our calculations provide useful guidelines for further experimental optimization of the magnetic performances of these alloys.« less

  17. Plant cyclopeptide RA-V kills human breast cancer cells by inducing mitochondria-mediated apoptosis through blocking PDK1AKT 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.

  18. Dielectric properties of Ba{sub 3-x}K{sub x}CaNb{sub 2}O{sub 9-{delta}} (0.5 < x < 1.25) (KBCN) double perovskites

    SciTech Connect (OSTI)

    Bhella, Surinderjit Singh; Thangadurai, Venkataraman

    2011-05-15

    Graphical abstract: Electrical conductivity, dielectric constant and dielectric loss of Ba{sub 1.75}K{sub 1.25}CaNb{sub 2}O{sub 9-{delta}} in air at 400-700 {sup o}C. Research highlights: {yields} We show the effectiveness of AC impedance spectroscopy to screen dielectric materials and to understand contributing effects on the dielectric properties of polycrystalline metal oxides. {yields} Unlike Ba{sub 3}CaNb{sub 2}O{sub 9}, Ba{sub 3-x}K{sub x}CaNb{sub 2}O{sub 9-{delta}} exhibits negligible grain-boundary and electrode effects to the total electrical properties and is consistent with perovskite-type K-doped BaZrO{sub 3}. {yields} Among the samples investigated, Ba{sub 1.75}K{sub 1.25}CaNb{sub 2}O{sub 9-{delta}} sintered at 1100 {sup o}C showed the highest dielectric constant of 65 at 10{sup 6} Hz and dielectric loss of 0.14 at 400 {sup o}C in air. -- Abstract: We report synthesis, structure and dielectric properties of double perovskite-type Ba{sub 3-x}K{sub x}CaNb{sub 2}O{sub 9-{delta}} (x = 0.5, 0.75, 1, 1.25) (KBCN). Powder X-ray diffraction (XRD) confirmed the formation of double perovskite-type structure and lattice constant decreases with increasing K in KBCN. AC impedance study showed a single semicircle over the investigated temperatures and frequencies in dry H{sub 2}, H{sub 2} + 3% H{sub 2}O, 3% H{sub 2}O + N{sub 2}, while two semicircles were observed at low temperatures in air, which could be attributed to bulk and grain-boundary contributions. Unlike un-doped BCN, KBCN exhibits negligible grain-boundary and electrode effects to the total electrical properties and is consistent with perovskite-type K-doped BaZrO{sub 3}. The bulk dielectric constant and dielectric loss were found to increase with increasing K content in KBCN and also found to change with sintering temperature. Among the samples investigated, Ba{sub 1.75}K{sub 1.25}CaNb{sub 2}O{sub 9-{delta}} sintered at 1100 {sup o}C showed the highest dielectric constant of 65 at 10{sup 6} Hz and

  19. Radiation Stability of Mo2Zr Phase as an Interaction Product in U-10M0/Zr/Al 6061 Monolithic Fuel Plate

    SciTech Connect (OSTI)

    Jian Gan; Brandon D. Miller; Dennis D. Keiser; Daniel M. Wachs; W. Sprowes; Y. H. Sohn; M. Kirk

    2015-04-01

    Abstract Monolithic U-10Mo alloy fuel plates with Al-6061 cladding are being developed for use in research and test reactors as low enrichment fuel (< 20% U-235 enrichment). These fuel plates contain a Zr diffusion barrier between the U-10Mo fuel and Al-6061 cladding that suppresses the interaction between the two that is known to be problematic under irradiation. However, the Zr also interacts with the U-10Mo and Al-6061 cladding during fuel fabrication to produce a variety of interaction phases. The results from recent post-irradiation-examination (PIE) of the irradiated monolithic fuel plates suggested that the microstructural development of the U-10Mo/Zr interaction phases under irradiation may have an impact on fuel performance. The Mo2Zr phase has been identified as a major interaction product at the interface of U-10Mo and Zr. TEM in-situ irradiation with 500 keV Kr ions at 200 ?C temperature to 2?1016 ions/cm2 was carried out to investigate its radiation stability. The Mo2Zr undergoes a radiation-induced structural change, from a large cubic (cF24, a0 = 0.7588 nm) to a small bcc cubic (cI2, a0 = 0.3185 nm), along with an estimated 11.3% volume contraction without changing its composition. The Mo2Zr phase demonstrated exceptional radiation tolerance with the development of dislocation showing no evidence of bubble formation. The irradiation to the same ion dose with the reduced ion energy at 250 keV reveals a high concentration of small bubbles (< 2 nm) as a result of increased Kr ion retention in the sample. .

  20. Dissolution process for ZrO.sub.2 -UO.sub.2 -CaO fuels

    DOE Patents [OSTI]

    Paige, Bernice E.

    1976-06-22

    The present invention provides an improved dissolution process for ZrO.sub.2 -UO.sub.2 -CaO-type pressurized water reactor fuels. The zirconium cladding is dissolved with hydrofluoric acid, immersing the ZrO.sub.2 -UO.sub.2 -CaO fuel wafers in the resulting zirconium-dissolver-product in the dissolver vessel, and nitric acid is added to the dissolver vessel to facilitate dissolution of the uranium from the ZrO.sub.2 -UO.sub.2 -CaO fuel wafers.

  1. 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.

  2. 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.; Utsunomiya, H.; Akimune, H.; Yamagata, T.; Okamoto, A.; Kondo, T.; Nakada, H.; Kawabata, T.; Fujita, Y.; Matsubara, H.; Shimbara, Y.; Nagashima, M.; Sakuda, M.; Mori, T.; 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.

  3. 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.

  4. The comparative kinetics of Ca, Sr, And Ra in a freshwater turtle, Trachemys scripta

    SciTech Connect (OSTI)

    Hinton, T.G.

    1989-01-01

    The accumulation of {sup 45}Ca, {sup 47}Ca, {sup 88}Sr, and {sup 226}Ra was studied in the yellow-bellied slider, a common freshwater turtle of the Southeastern US. The author was particularly interested in testing the hypothesis of competitive inhibition, a concept whereby decreasing the intake of a stable dietary element increases the absorption and retention of chemically similar radionuclides. He established four specific hypotheses and examined the processes of absorption and elimination as a function of stable dietary calcium (2 and 20 mg g{sup {minus}1}), season (summer, fall, winter and spring), and age and sex of the animals (hatchlings, juveniles, adult males, adult females, and gravid females). Turtles were gavaged with radionuclides and the gamma-emitting isotopes were detected during serial whole-body counts performed on the live animals for up to 480 d. The analysis of the beta-emitting {sup 45}Ca was accomplished by chemical separation procedures. Data were fit to a two-component exponential retention model by nonlinear regression. The 10-fold reduction in dietary Ca did not affect the elimination rate constants, and increased the assimilation of Sr and Ra only within juveniles. For all animals the absorption of Ca was significantly greater than Sr, and likewise, Sr was greater than Ra. Mean absorptions were generally higher than values reported for other organisms. Unlike many other organisms, absorption rates did not decline at maturity. He suspects that high Ca demands in constructing and maintaining the massive shell, necessitated by the turtle's survival strategy, may contribute to the high absorption, as well as the lack of a decline at maturity. Elimination rate constants were greatest in the summer and declined to levels that were generally not distinguishable from zero in the spring, winter, and fall seasons.

  5. Special Report: OAS-RA-12-03 | Department of Energy

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

    2-03 Special Report: OAS-RA-12-03 January 18, 2012 Lessons Learned/Best Practices during the Department of Energy's Implementation of the American Recovery and Reinvestment Act of 2009 The American Recovery and Reinvestment Act of 2009 (Recovery Act) was signed into law on February 17, 2009 as a way to jumpstart the U.S. economy, create or save millions of jobs, spur technological advances in science and health, and invest in the Nation's energy future. As part of the Recovery Act, the

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

    SciTech Connect (OSTI)

    Mahammad, F. M.; Mahammed, S. F.; Kumar, R.; Vijay, Y. K.; Sharma, B. K.; Sharma, G.

    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.

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

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

    Metal-Organic Frameworks Based on Previously Unknown Zr8Hf Cubic Clusters Previous Next List Dawei Feng, Hai-Long Jiang, Ying-Pin Chen, Zhi-Yuan Gu, Zhangwen Wei, and Hong-Cai...

  8. Aqueous phase hydrodeoxygenation of polyols over Pd/WO3-ZrO2...

    Office of Scientific and Technical Information (OSTI)

    Aqueous phase hydrodeoxygenation of polyols over PdWO3-ZrO2: Role of Pd-WO3 interaction and hydrodeoxygenation pathway Citation Details In-Document Search This content will become ...

  9. Quarkonium Spectroscopy and New States from BaBar

    SciTech Connect (OSTI)

    Vitale, L.; /Trieste U. /INFN, Trieste

    2007-06-08

    We review results on charmonium and bottomonium spectroscopy by the BaBar experiment at the PEP-II e{sup +}e{sup -} collider at SLAC. More space is reserved to the new results like the observation of hadronic non-B{bar B} {Upsilon}(4S) decays and the investigation on the production and decay properties of the recently discovered charmonium-like states X(3872) and Y (4260). These results are preliminary, unless otherwise specified.

  10. 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.

  11. Development of a new casting method to fabricate UZr 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 UZr 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: U10 wt% Zr, U10 wt% Zr5 wt% RE, and U10 wt% Zr5 wt% RE5 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 UZrREMn fuel slug showed that nearly all of the manganese was retained when casting was done under an inert atmosphere.

  12. Theoretical calculation of the melting curve of Cu-Zr binary alloys

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

    Gunawardana, K. G.S.H.; Wilson, S. R.; Mendelev, M. I.; Song, Xueyu

    2014-11-14

    Helmholtz free energies of the dominant binary crystalline solids found in the Cu-Zr system at high temperatures close to the melting curve are calculated. This theoretical approach combines fundamental measure density functional theory (applied to the hard-sphere reference system) and a perturbative approach to include the attractive interactions. The studied crystalline solids are Cu(fcc), Cu51Zr14(β), CuZr(B2), CuZr2(C11b), Zr(hcp), and Zr(bcc). The calculated Helmholtz free energies of crystalline solids are in good agreement with results from molecular-dynamics (MD) simulations. Using the same perturbation approach, the liquid phase free energies are calculated as a function of composition and temperature, from which themore » melting curve of the entire composition range of this system can be obtained. Phase diagrams are determined in this way for two leading embedded atom method potentials, and the results are compared with experimental data. Furthermore, theoretical melting temperatures are compared both with experimental values and with values obtained directly from MD simulations at several compositions.« less

  13. Theoretical calculation of the melting curve of Cu-Zr binary alloys

    SciTech Connect (OSTI)

    Gunawardana, K. G.S.H.; Wilson, S. R.; Mendelev, M. I.; Song, Xueyu

    2014-11-14

    Helmholtz free energies of the dominant binary crystalline solids found in the Cu-Zr system at high temperatures close to the melting curve are calculated. This theoretical approach combines fundamental measure density functional theory (applied to the hard-sphere reference system) and a perturbative approach to include the attractive interactions. The studied crystalline solids are Cu(fcc), Cu51Zr14(β), CuZr(B2), CuZr2(C11b), Zr(hcp), and Zr(bcc). The calculated Helmholtz free energies of crystalline solids are in good agreement with results from molecular-dynamics (MD) simulations. Using the same perturbation approach, the liquid phase free energies are calculated as a function of composition and temperature, from which the melting curve of the entire composition range of this system can be obtained. Phase diagrams are determined in this way for two leading embedded atom method potentials, and the results are compared with experimental data. Furthermore, theoretical melting temperatures are compared both with experimental values and with values obtained directly from MD simulations at several compositions.

  14. Radiation tolerant nanocrystalline ZrN films under high dose heavy-ion irradiations

    SciTech Connect (OSTI)

    Jiao, L.; Wang, H.; Yu, K. Y.; Chen, D.; Jacob, C.; Shao, L.; Zhang, X.

    2015-04-14

    ZrN, a refractory ceramic material, finds many potential applications in advanced nuclear reactors. However, the grain size dependent radiation response in nanocrystalline (nc) ZrN under high dose heavy ion irradiation has not yet been studied to date. Here, we compare the radiation response of nc-ZrN films (with a respective average grain size of ∼9 and 31 nm) to Fe{sup 2+} ion irradiations up to a damage level of 10 displacements-per-atom (dpa). The ZrN film with the average grain size of 9 nm shows prominently enhanced radiation tolerance as evidenced by suppressed grain growth, alleviated radiation softening, as well as reduced variation in electrical resistivity. In contrast, ZrN with the larger average grain size of 31 nm shows prominent radiation softening and resistivity increase, attributed to the high density of defect cluster formed inside the grains. The influence of grain boundaries on enhanced irradiation tolerance in nc-ZrN is discussed.

  15. In situ HVEM studies of phase transformation in Zr alloys and compounds under irradiation

    SciTech Connect (OSTI)

    Motta, A.T.; Faldowski, J.A.; Howe, L.M.; Okamoto, P.R.

    1996-01-01

    The High Voltage Electron Microscope (HVEM)/Tandem facility at Argonne National Laboratory has been used to conduct detailed studies of the phase stability and microstructural evolution in zirconium alloys and compounds under ion and electron irradiation. Detailed kinetic studies of the crystalline-to-amorphous transformation of the intermetallic compounds Zr{sub 3}(Fe{sub 1-x}Ni{sub x}), Zr(Fe{sub 1-x},Cr{sub x}){sub 2}, Zr{sub 3}Fe, and Zr{sub 1.5} Nb{sub 1.5} Fe, both as second phase precipitates and in bulk form, have been performed using the in-situ capabilities of the Argonne facility, under a variety of irradiation conditions (temperature, dose rate). Results include a verification of a dose rate effect on amorphization and the influence of material variables (stoichiometry x, presence of stacking faults, crystal structure) on the critical temperature and on the critical dose for amorphization. Studies were also conducted of the microstructural evolution under irradiation of specially tailored binary and ternary model alloys. The stability of the {omega}-phase in Zr-20%Nb under electron and Ar ion irradiation was investigated as well as the {beta}-phase precipitation in Zr-2.5%Nb under Ar ion irradiation. The ensemble of these results is discussed in terms of theoretical models of amorphization and of irradiation-altered solubility.

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

    SciTech Connect (OSTI)

    Hunn, John D; Kercher, Andrew K

    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.

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

    SciTech Connect (OSTI)

    Kercher, Andrew K; Hunn, John D

    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.

  18. Zr-based bulk metallic glass as a cylinder material for high pressure apparatuses

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

    Komatsu, Kazuki; Munakata, Koji; Matsubayashi, Kazuyuki; Uwatoko, Yoshiya; Yokoyama, Yoshihiko; Sugiyama, Kazumasa; Matsuda, Masaaki

    2015-05-12

    Zirconium-based bulk metallic glass (Zr-based BMG) has outstanding properties as a cylinder mate- rial for piston-cylinder high pressure apparatuses and is especially useful for neutron scattering. The piston-cylinder consisting of a Zr-based BMG cylinder with outer/inner diameters of 8.8/2.5 mm sustains pressures up to 1.81 GPa and ruptured at 2.0 GPa, with pressure values determined by the superconduct- ing temperature of lead. The neutron attenuation of Zr-based BMG is similar to that of TiZr null-scattering alloy and more transparent than that of CuBe alloy. No contamination of sharp Bragg reflections is observed in the neutron diffraction pattern for Zr-based BMG.more » The magnetic susceptibility of Zr-based BMG is similar to that of CuBe alloy; this leads to a potential application for measurements of magnetic properties under pressure.« less

  19. Structural and chemical characterization of BaTiO{sub 3} nanorods

    SciTech Connect (OSTI)

    Zagar, K.; Recnik, A.; Sturm, S.; Gajovic, A.; Ceh, M.

    2011-03-15

    Research highlights: {yields} Polycrystalline BaTiO{sub 3} nanorods were synthesized with EPD into AAO templates. {yields} Nanorods are composed of crystalline, nanosized grains with pseudo-cubic structure. {yields} Integrowth of hexagonal BaTiO{sub 3} polymorph within pseudo-cubic structure was observed. -- Abstract: An electron-microscopy investigation was performed on BaTiO{sub 3} nanorods that were processed by sol-gel electrophoretic deposition (EPD) into anodic aluminium oxide (AAO) membranes. The BaTiO{sub 3} nanorods grown within the template membranes had diameters ranging from 150 to 200 nm, with an average length of 10-50 {mu}m. By using various electron-microscopy techniques we showed that the processed BaTiO{sub 3} nanorods were homogeneous in their chemical composition. The BaTiO{sub 3} nanorods were always polycrystalline and were composed of well-crystallized, defect-free, pseudo-cubic BaTiO{sub 3} grains, ranging from 10 to 30 nm. No intergranular phases were observed between the BaTiO{sub 3} grains. A low-temperature hexagonal polymorph that is coherently intergrown with the BaTiO{sub 3} perovskite matrix was also observed as a minor phase. When annealing the AAO templates containing the BaTiO{sub 3} sol in an oxygen atmosphere the presence of the hexagonal polymorph was diminished.

  20. 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)

  1. Formation, characterization and reactivity of adsorbed oxygen on BaO/Pt(111)

    SciTech Connect (OSTI)

    Mudiyanselage, Kumudu; Mei, Donghai; Yi, Cheol-Woo; Weaver, Jason F.; Szanyi, Janos

    2010-12-02

    The formation of adsorbed O (Oad) species and their reactivities in CO oxidation on BaO/Pt(111) (at two BaO coverages) were studied with temperature programmed desorption (TPD), infrared reflection absorption (IRA) and X-ray photoelectron (XP) spectroscopies. In neither of these two systems was the Pt(111) surface completely covered with BaO. On the system with lower BaO coverage (~45 % of the Pt(111) surface is covered by BaO), two different Oad species form following the adsorption of O2 at 300 K: O adsorbed on BaO-free Pt(111) sites (OPt) and at the Pt-BaO interface (Oint). On the system with higher BaO coverage (~60 % of the Pt(111) surface is covered by BaO), two types of Oint are seen at the Pt-BaO interface. The desorption of OPt from the BaO-free portion of the Pt(111) surface gives an O2 desorption peak with a maximum desorption rate at ~690 K. Migration of Oint to the Pt(111) sites and their recombinative desorption give two explosive desorption features at ~760 and ~790 K in the TPD spectrum. The reactivities of these Oad species with CO to form CO2 follow their sequence of desorption; i.e., the OPt associated with the BaO-free Pt(111) surface, which desorbs at 690 K, reacts first with CO, followed by the Oint species at the Pt-BaO interface (first the one that desorbs at ~760 K and finally the one that is bound the most strongly to the interface, and desorbs at ~790 K). This work was supported by the US Department of Energy Basic Energy Sciences' Chemical Sciences, Geosciences & Biosciences Division. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  2. Water adsorption induced in-plane domain switching on BaTiO{sub 3} surface

    SciTech Connect (OSTI)

    Li, X.; Bai, Y.; Su, Y. J.; Wang, B. C.

    2015-09-07

    In this study, the influences of the adsorption of water molecules on the changes in the atomic and electric structures of BaTiO{sub 3} surface were investigated using ab initio calculation. Water molecules are molecularly and dissociatively adsorbed on the BaTiO{sub 3} surface, which makes electrons transfer from water molecules to the BaTiO{sub 3} surface. The redistribution of electrons in the BaTiO{sub 3} surface layers weakens the Ba-O interactions and strengthens the Ti-O interactions, so that the Ti atom shifts in TiO{sub 2} plane, i.e., an in-plane domain switching. The adsorption of water molecules on BaTiO{sub 3} surfaces also results in a reduction in the surface rumpling.

  3. Collaborative Physical and Biological Dosimetry Studies for Neutron Capture Therapy at the RA-1 Research Reactor Facility

    SciTech Connect (OSTI)

    David W. Nigg; Amanda E. Schwint; John K. Hartwell; Elisa M. Heber; Veronica Trivillin; Jorge Castillo; Luis Wentzeis; Patrick Sloan; Charles A. Wemple

    2004-10-01

    Initial physical dosimetry measurements have been completed using activation spectrometry and thermoluminiscent dosimeters to characterize the BNCT irradiation facility developed at the RA-1 research reactor operated by the Argentine National Atomic Energy Commission in Buenos Aires. Some biological scoping irradiations have also been completed using a small-animal (hamster) oral mucosa tumor model. Results indicate that the RA-1 neutron source produces useful dose rates but that some improvements in the initial configuration will be needed to optimize the spectrum for thermal-neutron BNCT research applications.

  4. Ba{sub 2}TeO: A new layered oxytelluride

    SciTech Connect (OSTI)

    Besara, T.; Ramirez, D.; Sun, J.; Whalen, J.B.; Tokumoto, T.D.; McGill, S.A.; Singh, D.J.; Siegrist, T.

    2015-02-15

    Single crystals of the new semiconducting oxytelluride phase, Ba{sub 2}TeO, were synthesized from barium oxide powder and elemental tellurium in a molten barium metal flux. Ba{sub 2}TeO crystallizes in tetragonal symmetry with space group P4/nmm (#129), a=5.0337(1) Å, c=9.9437(4) Å, Z=2. The crystals were characterized by single crystal x-ray diffraction, heat capacity and optical measurements. The optical measurements along with electronic band structure calculations indicate semiconductor behavior with a band gap of 2.93 eV. Resistivity measurements show that Ba{sub 2}TeO is highly insulating. - Graphical abstract: Starting from a simple stacking of rocksalt layers, the final structure of Ba{sub 2}TeO can be obtained by accommodation of structural strain via atom displacements. Density of states calculations and optical absorbance measurements show that Ba{sub 2}TeO has a band gap of 2.93 eV, indicative of semiconductor behavior. - Highlights: • Single crystal synthesis of a new layered oxytelluride, Ba{sub 2}TeO. • The structure features inverse PbO-type BaO layers and NaCl-type BaTe layers. • Optical absorbance show Ba{sub 2}TeO to be a semiconductor with a 2.93 eV gap. • Density of states indicate a small hybridization between Te 5p and Ba 5d states. • The BaTe (BaO) layers dominate the heat capacity at low (high) temperatures.

  5. Inter-atomic force constants of BaF{sub 2} by diffuse neutron scattering measurement

    SciTech Connect (OSTI)

    Sakuma, Takashi Makhsun,; Sakai, Ryutaro; Xianglian; Takahashi, Haruyuki; Basar, Khairul; Igawa, Naoki; Danilkin, Sergey A.

    2015-04-16

    Diffuse neutron scattering measurement on BaF{sub 2} crystals was performed at 10?K and 295?K. Oscillatory form in the diffuse scattering intensity of BaF{sub 2} was observed at 295?K. The correlation effects among thermal displacements of F-F atoms were obtained from the analysis of oscillatory diffuse scattering intensity. The force constants among neighboring atoms in BaF{sub 2} were determined and compared to those in ionic crystals and semiconductors.

  6. Special features of the isospin splitting of the giant dipole resonance in the {sup 90}Zr nucleus

    SciTech Connect (OSTI)

    Varlamov, V. V. Peskov, N. N.; Stepanov, M. E.

    2009-02-15

    Data on the proton and neutron channels of the {sup 90}Zr photodisintegration were analyzed in detail, basic parameters of the isospin splitting of the giant dipole resonance in {sup 90}Zr being determined by the properties of these channels. New data concerning the cross sections for the partial photoneutron reactions {sup 90}Zr({gamma}, n){sup 89}Zr and {sup 90}Zr({gamma}, 2n){sup 88}Zr and resulting from a simultaneous correction of data from experiments performed in Livermore (USA) and Saclay (France) by using beams of quasimonoenergetic annihilation photons were invoked. Use was made of information about the positions on the energy scale of states characterized by different isospin values in the {sup 90}Zr nucleus and nuclei neighboring it, which are members of the respective isospin multiplet. New data on the parameters of the isospin splitting of the giant dipole resonance in the {sup 90}Zr nucleus were obtained on the basis of a global analysis of data on the giant-dipole-resonance states of the {sup 90}Zr nucleus, which are manifested in the respective photoneutron and photoproton cross sections and in their decay channels involving states of different isospin in neighboring nuclei.

  7. High thermal stability of La2O3 and CeO2-stabilized tetragonal ZrO2

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

    Wang, Shichao; Xie, Hong; Lin, Yuyuan; Poeppelmeier, Kenneth R.; Li, Tao; Winans, Randall E.; Cui, Yanran; Ribeiro, Fabio H.; Canlas, Christian P.; Elam, Jeffrey W.; et al

    2016-02-15

    Catalyst support materials of tetragonal ZrO2, stabilized by either La2O3 (La2O3-ZrO2) or CeO2 (CeO2-ZrO2), were synthesized under hydrothermal conditions at 200 °C with NH4OH or tetramethylammonium hydroxide as the mineralizer. From In Situ synchrotron powder X-ray diffraction and small-angle X-ray scattering measurements, the calcined La2O3-ZrO2 and CeO2-ZrO2 supports were nonporous nanocrystallites that exhibited rectangular shapes with thermal stability up to 1000 °C in air. These supports had an average size of ~10 nm and a surface area of 59-97 m2/g. The catalysts Pt/La2O3-ZrO2 and Pt/CeO2-ZrO2 were prepared by using atomic layer deposition with varying Pt loadings from 6.3-12.4 wt %.more » Mono-dispersed Pt nanoparticles of ~3 nm were obtained for these catalysts. As a result, the incorporation of La2O3 and CeO2 into the t-ZrO2 structure did not affect the nature of the active sites for the Pt/ZrO2 catalysts for the water-gas-shift (WGS) reaction.« less

  8. Observation of the chiral magnetic effect in ZrTe₅

    SciTech Connect (OSTI)

    Li, Qiang; Kharzeev, Dmitri E.; Zhang, Cheng; Huang, Yuan; Pletikosic, I.; Fedorov, A. V.; Zhong, R. D.; Schneeloch, J. A.; Gu, G. D.; Valla, T.

    2015-02-08

    The chiral magnetic effect is the generation of electric current induced by chirality imbalance in the presence of magnetic field. It is a macroscopic manifestation of the quantum anomaly in relativistic field theory of chiral fermions (massless spin 1/2 particles with a definite projection of spin on momentum) – a dramatic phenomenon arising from a collective motion of particles and antiparticles in the Dirac sea. The recent discovery of Dirac semimetals with chiral quasi-particles opens a fascinating possibility to study this phenomenon in condensed matter experiments. Here we report on the first observation of chiral magnetic effect through the measurement of magneto-transport in zirconium pentatelluride, ZrTe₅. Our angle-resolved photoemission spectroscopy experiments show that this material’s electronic structure is consistent with a 3D Dirac semimetal. We observe a large negative magnetoresistance when magnetic field is parallel with the current. The measured quadratic field dependence of the magnetoconductance is a clear indication of the chiral magnetic effect. Furthermore, the observed phenomenon stems from the effective transmutation of Dirac semimetal into a Weyl semimetal induced by the parallel electric and magnetic fields that represent a topologically nontrivial gauge field background.

  9. Chiral magnetic effect in ZrTe5

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

    Li, Q.; Kharzeev, D. E.; Zhang, C.; Huang, Y.; Pletikosic, I.; Fedorov, A. V.; Zhong, R. D.; Schneeloch, J. A.; Gu, G. D.; Valla, T.

    2016-02-08

    The chiral magnetic effect is the generation of electric current induced by chirality imbalance in the presence of magnetic field. It is a macroscopic manifestation of the quantum anomaly in relativistic field theory of chiral fermions (massless spin 1/2 particles with a definite projection of spin on momentum) - a dramatic phenomenon arising from a collective motion of particles and antiparticles in the Dirac sea. The recent discovery of Dirac semimetals with chiral quasi-particles opens a fascinating possibility to study this phenomenon in condensed matter experiments. Here we report on the measurement of magneto-transport in zirconium pentatelluride, ZrTe5 that providesmore » a strong evidence for the chiral magnetic effect. Our angleresolved photoemission spectroscopy experiments show that this material’s electronic structure is consistent with a 3D Dirac semimetal. We observe a large negative magnetoresistance when magnetic field is parallel with the current. The measured quadratic field dependence of the magnetoconductance is a clear indication of the chiral magnetic effect. The observed phenomenon stems from the effective transmutation of Dirac semimetal into a Weyl semimetal induced by the parallel electric and magnetic fields that represent a topologically nontrivial gauge field background. We expect that chiral magnetic effect may emerge in a wide class of materials that are near the transition between the trivial and topological insulators.« less

  10. Observation of the chiral magnetic effect in ZrTe₅

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

    Li, Qiang; Kharzeev, Dmitri E.; Zhang, Cheng; Huang, Yuan; Pletikosic, I.; Fedorov, A. V.; Zhong, R. D.; Schneeloch, J. A.; Gu, G. D.; Valla, T.

    2015-02-08

    The chiral magnetic effect is the generation of electric current induced by chirality imbalance in the presence of magnetic field. It is a macroscopic manifestation of the quantum anomaly in relativistic field theory of chiral fermions (massless spin 1/2 particles with a definite projection of spin on momentum) – a dramatic phenomenon arising from a collective motion of particles and antiparticles in the Dirac sea. The recent discovery of Dirac semimetals with chiral quasi-particles opens a fascinating possibility to study this phenomenon in condensed matter experiments. Here we report on the first observation of chiral magnetic effect through the measurementmore » of magneto-transport in zirconium pentatelluride, ZrTe₅. Our angle-resolved photoemission spectroscopy experiments show that this material’s electronic structure is consistent with a 3D Dirac semimetal. We observe a large negative magnetoresistance when magnetic field is parallel with the current. The measured quadratic field dependence of the magnetoconductance is a clear indication of the chiral magnetic effect. Furthermore, the observed phenomenon stems from the effective transmutation of Dirac semimetal into a Weyl semimetal induced by the parallel electric and magnetic fields that represent a topologically nontrivial gauge field background.« less

  11. Determination of the direct double- β -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-β 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-β decay. The LEBIT Penning trap mass spectrometer was used for the first direct experimental determination of the ⁹⁶Zr double-β decay Q value: Qββ=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-σ shift is primarily due to a more accurate measurement of the ⁹⁶Zr atomic mass: m(⁹⁶Zr)=95.90827735(17) u. Using the new Q value, the 2νββ-decay matrix element, |M2ν|, 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 ¹²C₈ and ⁸⁷Rb as references are also reported.« less

  12. 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

  13. Mechanism of abnormally slow crystal growth of CuZr alloy

    SciTech Connect (OSTI)

    Yan, X. Q.; Lü, Y. J.

    2015-10-28

    Crystal growth of the glass-forming CuZr alloy is shown to be abnormally slow, which suggests a new method to identify the good glass-forming alloys. The crystal growth of elemental Cu, Pd and binary NiAl, CuZr alloys is systematically studied with the aid of molecular dynamics simulations. The temperature dependence of the growth velocity indicates the different growth mechanisms between the elemental and the alloy systems. The high-speed growth featuring the elemental metals is dominated by the non-activated collision between liquid-like atoms and interface, and the low-speed growth for NiAl and CuZr is determined by the diffusion across the interface. We find that, in contrast to Cu, Pd, and NiAl, a strong stress layering arisen from the density and the local order layering forms in front of the liquid-crystal interface of CuZr alloy, which causes a slow diffusion zone. The formation of the slow diffusion zone suppresses the interface moving, resulting in much small growth velocity of CuZr alloy. We provide a direct evidence of this explanation by applying the compressive stress normal to the interface. The compression is shown to boost the stress layering in CuZr significantly, correspondingly enhancing the slow diffusion zone, and eventually slowing down the crystal growth of CuZr alloy immediately. In contrast, the growth of Cu, Pd, and NiAl is increased by the compression because the low diffusion zones in them are never well developed.

  14. Method of forming superconducting Tl-Ba-Ca-Cu-O films

    DOE Patents [OSTI]

    Wessels, Bruce W.; Marks, Tobin J.; Richeson, Darrin S.; Tonge, Lauren M.; Zhang, Jiming

    1993-01-01

    A method of forming a superconducting Tl-Ba-Ca-Cu-O film is disclosed, which comprises depositing a Ba-Ca-Cu-O film on a substrate by MOCVD, annealing the deposited film and heat-treating the annealed film in a closed circular vessel with TlBa.sub.2 Ca.sub.2 Cu.sub.3 O.sub.x and cooling to form said superconducting film of TlO.sub.m Ba.sub.2 Ca.sub.n-1 Cu.sub.n O.sub.2n+2, wherein m=1,2 and n=1,2,3.

  15. A A S BA IMPORTANT ISSUES W BOOK TWO O

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

    i * A * A S BA IMPORTANT ISSUES W BOOK TWO O * - U.S. Department of Energy, Transition 2008 - HOT Issue Papers Section 1 - Energy 1-1 Carbon Capture and Storage (CCS) * CCS could be developed and accelerated to meet aggressive C02 emissions goals. This strategy includes FutureGen and Clean Coal Power Initiative (CCPI). * July 2009 - Select CCPI recipients (closes 1/15/09) * December 2009 - Award FutureGen based on a December 2008 selection 1-2 Next Generation Nuclear Plant (NGNP) Partnership

  16. 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.

  17. 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

  18. 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)

  19. Optimization and testing results of Zr-bearing ferritic steels

    SciTech Connect (OSTI)

    Tan, Lizhen; Yang, Ying; Tyburska-Puschel, Beata; Sridharan, K.

    2014-09-01

    The mission of the Nuclear Energy Enabling Technologies (NEET) program is to develop crosscutting technologies for nuclear energy applications. Advanced structural materials with superior performance at elevated temperatures are always desired for nuclear reactors, which can improve reactor economics, safety margins, and design flexibility. They benefit not only new reactors, including advanced light water reactors (LWRs) and fast reactors such as sodium-cooled fast reactor (SFR) that is primarily designed for management of high-level wastes, but also life extension of the existing fleet when component exchange is needed. Developing and utilizing the modern materials science tools (experimental, theoretical, and computational tools) is an important path to more efficient alloy development and process optimization. Ferritic-martensitic (FM) steels are important structural materials for nuclear reactors due to their advantages over other applicable materials like austenitic stainless steels, notably their resistance to void swelling, low thermal expansion coefficients, and higher thermal conductivity. However, traditional FM steels exhibit a noticeable yield strength reduction at elevated temperatures above ~500°C, which limits their applications in advanced nuclear reactors which target operating temperatures at 650°C or higher. Although oxide-dispersion-strengthened (ODS) ferritic steels have shown excellent high-temperature performance, their extremely high cost, limited size and fabricability of products, as well as the great difficulty with welding and joining, have limited or precluded their commercial applications. Zirconium has shown many benefits to Fe-base alloys such as grain refinement, improved phase stability, and reduced radiation-induced segregation. The ultimate goal of this project is, with the aid of computational modeling tools, to accelerate the development of a new generation of Zr-bearing ferritic alloys to be fabricated using conventional

  20. Direct spectroscopic evidence for completely filled Cu 3d shell in BaCu₂As₂ and α – BaCu₂Sb₂

    SciTech Connect (OSTI)

    Wu, S. F.; Richard, P.; van Roekeghem, A.; Nie, S. M.; Miao, H.; Xu, N.; Qian, T.; Saparov, B.; Fang, Z.; Biermann, S.; Sefat, Athena S.; Ding, H.

    2015-06-08

    We use angle-resolved photoemission spectroscopy to extract the band dispersion and the Fermi surface of BaCu₂As₂ and α - BaCu₂Sb₂. While the Cu 3d bands in both materials are located around 3.5 eV below the Fermi level, the low-energy photoemission intensity mainly comes from As 4p states, suggesting a completely filled Cu 3d shell. The splitting of the As 3d core levels and the lack of pronounced three-dimensionality in the measured band structure of BaCu₂As₂ indicate a surface state likely induced by the cleavage of this material in the collapsed tetragonal phase, which is consistent with our observation of a Cu⁺¹ oxidation state. However, the observation of Cu states at similar energy in α - BaCu₂Sb₂ without the pnictide-pnictide interlayer bonding characteristic of the collapsed tetragonal phase suggests that the short interlayer distance in BaCu₂As₂ follows from the stability of the Cu⁺¹ rather than the other way around. Our results confirm the prediction that BaCu₂As₂ is an sp metal with weak electronic correlations.

  1. Dipole strength distributions in the stable Ba isotopes {sup 134-138}Ba: A study in the mass region of a nuclear shape transition

    SciTech Connect (OSTI)

    Scheck, M.; Garrel, H. von; Belic, D.; Kneissl, U.; Kohstall, C.; Nord, A.; Pitz, H.H.; Stedile, F.; Tsoneva, N.; Brentano, P. von; Fransen, C.; Gade, A.; Jolie, J.; Linnemann, A.; Pietralla, N.; Werner, V.; Stoyanov, C.

    2004-10-01

    The low-lying dipole strength distributions in the odd-mass isotopes {sup 135,137}Ba were studied in nuclear resonance fluorescence experiments (NRF) performed at the Stuttgart Dynamitron facility using bremsstrahlung beams with end point energies of 4.1, 3.1, and 2.5 MeV. Numerous excited states, most of them unknown so far, were observed in the excitation energy range up to 4 MeV. Detailed spectroscopic information has been obtained on excitation energies, decay widths, decay branching ratios, and transition probabilities. The results for {sup 137}Ba are compared with calculations in the framework of the Quasiparticle-Phonon Model. The new data for {sup 135,137}Ba complete the systematics of low-lying dipole excitations as observed for the even Ba isotopes {sup 134,136,138}Ba in previous NRF experiments in Stuttgart. The complete systematics within the Ba isotopic chain, exhibiting a nuclear shape transition, is discussed with respect to E1 two-phonon excitations, M1 scissors mode excitations, and in regard to the new critical point symmetries.

  2. Submillimeter and microwave residual losses in epitaxial films of Y-Ba-Cu-O and Tl-Ca-Ba-Cu-O

    SciTech Connect (OSTI)

    Miller, D.; Richards, P.L.; Garrison, S.M.; Newman, N.; Eom, C.B.; Geballe, T.H.; Etemad, S.; Inam, A.; Venkatesan, T.; Martens, J.S.; Lee, W.Y.; Bourne, L.C.

    1992-03-01

    We have used a novel bolometric technique and a resonant technique to obtain accurate submillimeter and microwave residual loss data for epitaxial thin films of YBa{sub 2}Cu{sub 3}O{sub 7}, Tl{sub 2}Ca{sub 2}Ba{sub 2}Cu{sub 3}O{sub 10} and Tl{sub 2}CaBa{sub 2}Cu{sub 2}O{sub 8}. For all films we obtain good agreement between the submillimeter and microwave data, with the residual losses in both the Y-Ba-Cu-O and Tl-Ca-Ba-Cu-O films scaling approximately as frequency squared below {approximately} 1 THz. We are able to fit the losses in the Y-Ba-Cu-O films to a weakly coupled grain model for the a-b plane conductivity, in good agreement with results from a Kramers-Kronig analysis of the loss data. We observe strong phonon structure in the Tl-Ca-Ba-Cu-O films for frequencies between 2 and 21 THz, and are unable to fit these losses to the simple weakly coupled grain model. This is in strong contrast to the case for other high {Tc} superconductors such as YBa{sub 2}Cu{sub 3}O{sub 7}, where phonon structure observed in ceramic samples is absent in epitaxial oriented films and crystals because of the electronic screening due to the high conductivity of the a-b planes.

  3. Direct spectroscopic evidence for completely filled Cu 3d shell in BaCu₂As₂ and α – BaCu₂Sb₂

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

    Wu, S. F.; Richard, P.; van Roekeghem, A.; Nie, S. M.; Miao, H.; Xu, N.; Qian, T.; Saparov, B.; Fang, Z.; Biermann, S.; et al

    2015-06-08

    We use angle-resolved photoemission spectroscopy to extract the band dispersion and the Fermi surface of BaCu₂As₂ and α - BaCu₂Sb₂. While the Cu 3d bands in both materials are located around 3.5 eV below the Fermi level, the low-energy photoemission intensity mainly comes from As 4p states, suggesting a completely filled Cu 3d shell. The splitting of the As 3d core levels and the lack of pronounced three-dimensionality in the measured band structure of BaCu₂As₂ indicate a surface state likely induced by the cleavage of this material in the collapsed tetragonal phase, which is consistent with our observation of amore » Cu⁺¹ oxidation state. However, the observation of Cu states at similar energy in α - BaCu₂Sb₂ without the pnictide-pnictide interlayer bonding characteristic of the collapsed tetragonal phase suggests that the short interlayer distance in BaCu₂As₂ follows from the stability of the Cu⁺¹ rather than the other way around. Our results confirm the prediction that BaCu₂As₂ is an sp metal with weak electronic correlations.« less

  4. Phonon properties of BaFe?X? (X=S, Se) spin ladder compounds

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

    Popovicq, Z. V.; Petrovic, C.; Scepanovic, M.; Lazarevic, N.; Opacic, M.; Radonjic, M. M.; Tanaskovic, D.; Lei, Hechang

    2015-02-27

    We present the Raman scattering spectra of the S=2 spin ladder compounds BaFe?X? (X=S,Se) in a temperature range between 20 and 400 K. Although the crystal structures of these two compounds are both orthorhombic and very similar, they are not isostructural. The unit cell of BaFe?S? (BaFe?Se?) is base-centered Cmcm (primitive Pnma), giving 18 (36) modes to be observed in the Raman scattering experiment. We have detected almost all Raman active modes, predicted by factor group analysis, which can be observed from the cleavage planes of these compounds. Assignment of the observed Raman modes of BaFe?S(Se)? is supported by themorelattice dynamics calculations. The antiferromagnetic long-range spin ordering in BaFe?Se? below TN=255K leaves a fingerprint both in the A1g and B3g phonon mode linewidth and energy.less

  5. Nanocrystalline BaTiO3 powder via ambient conditions sol process (Prop.2001-071)

    SciTech Connect (OSTI)

    Payzant, E Andrew; Wang, X.; Hu, Michael Z.; Blom, Douglas Allen

    2005-01-01

    Nanocrystalline BaTiO{sub 3} particles have been prepared by ambient condition sol (ACS) process starting from soluble precursors of barium and titanium yielding a mixed oxide/hydroxide gel. The gel was peptized and crystallized in water under a refluxing condition. Higher initial pH and Ba/Ti ratio led to smaller crystallite sizes of BaTiO{sub 3} powders. Organic mineralizer, tetramethylammonium hydroxide (TMAH), can adsorb on the BaTiO{sub 3} nuclei and inhibited further growth of the particles. Adding a polymer during BaTiO{sub 3} synthesis led to a smaller particle size and increased redispersibility of the particles in water.

  6. Physical properties of epitaxial ZrN/MgO(001) layers grown by reactive magnetron sputtering

    SciTech Connect (OSTI)

    Mei, A. B.; Zhang, C.; Sardela, M.; Eckstein, J. N.; Rockett, A.; Howe, B. M.; Hultman, L.; Petrov, I.; Greene, J. E.

    2013-11-15

    Single-crystal ZrN films, 830 nm thick, are grown on MgO(001) at 450 °C by magnetically unbalanced reactive magnetron sputtering. The combination of high-resolution x-ray diffraction reciprocal lattice maps, high-resolution cross-sectional transmission electron microscopy, and selected-area electron diffraction shows that ZrN grows epitaxially on MgO(001) with a cube-on-cube orientational relationship, (001){sub ZrN}‖(001){sub MgO} and [100]{sub ZrN}‖[100]{sub MgO}. The layers are essentially fully relaxed with a lattice parameter of 0.4575 nm, in good agreement with reported results for bulk ZrN crystals. X-ray reflectivity results reveal that the films are completely dense with smooth surfaces (roughness = 1.3 nm, consistent with atomic-force microscopy analyses). Based on temperature-dependent electronic transport measurements, epitaxial ZrN/MgO(001) layers have a room-temperature resistivity ρ{sub 300K} of 12.0 μΩ-cm, a temperature coefficient of resistivity between 100 and 300 K of 5.6 × 10{sup −8}Ω-cm K{sup −1}, a residual resistivity ρ{sub o} below 30 K of 0.78 μΩ-cm (corresponding to a residual resistivity ratio ρ{sub 300Κ}/ρ{sub 15K} = 15), and the layers exhibit a superconducting transition temperature of 10.4 K. The relatively high residual resistivity ratio, combined with long in-plane and out-of-plane x-ray coherence lengths, ξ{sub ‖} = 18 nm and ξ{sub ⊥} = 161 nm, indicates high crystalline quality with low mosaicity. The reflectance of ZrN(001), as determined by variable-angle spectroscopic ellipsometry, decreases slowly from 95% at 1 eV to 90% at 2 eV with a reflectance edge at 3.04 eV. Interband transitions dominate the dielectric response above 2 eV. The ZrN(001) nanoindentation hardness and modulus are 22.7 ± 1.7 and 450 ± 25 GPa.

  7. 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.

  8. Catalytic decomposition of Ba(NO3)2 on Pt(111)

    SciTech Connect (OSTI)

    Mudiyanselage, Kumudu; Weaver, Jason F.; Szanyi, Janos

    2011-04-07

    The decomposition of Ba(NO3)2 formed on BaO/Pt(111) (Pt(111) surface is partially covered by BaO) in the presence of CO was studied using temperature programmed desorption (TPD), infrared reflection absorption (IRA) and X-ray photoelectron (XP) spectroscopies. The exposure of BaO/Pt(111) to elevated NO2 pressure (1.0×10-4 Torr) at 450 K leads to the formation of Ba(NO3)2, chemisorbed O (OPt) and Pt-oxide-like domains. During TPD, the Ba(NO3)2 begins to thermally decompose near 490 K, releasing NO and NO2 with the maximum NOx desorption rate seen at 605 K. The OPt species formed following the exposure of BaO/Pt(111) to NO2 react with CO to release CO2 at 450 K. The consumption of OPt during CO oxidation initiates the migration of O from the Pt-oxide-like domains to the chemisorbed phase, where the CO oxidation reaction occurs. Therefore, the removal of OPt by CO leads to the reduction of oxidized Pt, and to the formation of metallic Pt(111) domains, where, subsequently, catalytic decomposition of Ba(NO3)2 can take place. The Pt-catalyzed decomposition of Ba(NO3)2 occurs readily at 450 K, a temperature much lower than the onset of the decomposition temperature of Ba(NO3)2 in the presence of oxidized Pt. This work was supported by the US Department of Energy Basic Energy Sciences' Chemical Sciences, Geosciences & Biosciences Division. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  9. 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: ζ-(U, Np, Pu, Am) (~70 at% U, 5% Np, 14% Pu, 1% Am, and 10% Zr) and δ-(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 ζ-(U, Np, Pu, Am) is higher than that in ζ-(U, Pu) and the Zr content in δ-(U, Np, Pu, Am)Zr2 is lower than that in δ-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 ζ-(U, Np, Pu, Am) bracketed by zones of δ-(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 ζ-(U, Np, Pu, Am) and δ-(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.

  10. Effect of cooling rate on the microstructure and microhardness of the CuZrAgAl alloy

    SciTech Connect (OSTI)

    Liu, Y.; Blandin, J.J.; Suery, M.; Kapelski, G.

    2012-08-15

    The effect of cooling rate on the microstructure and microhardness of the Cu{sub 40}Zr{sub 44}Ag{sub 8}Al{sub 8} (at.%) alloy has been studied. The crystalline phases were characterized by X-ray diffraction, optical microscopy and scanning electron microscopy with energy dispersive X-ray spectroscopy, and identified as AlCu{sub 2}Zr, Cu{sub 10}Zr{sub 7} and CuZr{sub 2}. The solidification sequence was established as following: the Cu{sub 10}Zr{sub 7} phase forms first in the periphery of the rod, then following with AlCu{sub 2}Zr phase in the rod center and finally CuZr{sub 2} crystals in Cu-depleted areas. The effect of crystals on the mechanical properties of the Cu{sub 40}Zr{sub 44}Ag{sub 8}Al{sub 8} alloy was also estimated through the microhardness. According to the value of microhardness, inhomogeneous structure of the amorphous matrix is more easily formed for the alloy in the low cooling rate (i.e., 9 mm) as compared with the alloy with fully amorphous state in the large cooling rate (i.e., 3 mm). This inhomogeneous structure was attributed to the composition change of amorphous matrix arising from the forming of crystalline phases due to the low cooling rate. - Highlights: Black-Right-Pointing-Pointer The crystalline phases in the Cu{sub 40}Zr{sub 44}Ag{sub 8}Al{sub 8} alloy were identified. Black-Right-Pointing-Pointer The solidification sequence of Cu{sub 40}Zr{sub 44}Ag{sub 8}Al{sub 8} alloy was verified. Black-Right-Pointing-Pointer The softening and hardening of alloy could be observed due to the crystallization.

  11. The role of the Ganges-Brahmaputra mixing zone in supplying barium and [sup 226]Ra to the Bay of Bengal

    SciTech Connect (OSTI)

    Carroll, J. Univ. of Alaska, Fairbanks ); Falkner, K.K. CNES, Toulouse ); Brown, E.T. ); Moore, W.S. )

    1993-07-01

    The Ganges-Brahmaputra river system is ranked fourth among world rivers as a source of freshwater to the oceans and is believed to supply more sediment to the ocean than any other; 1.5 [times] 10[sup 12] kg/yr (Milliman and Meade, 1983). Barium and [sup 226]Ra are typically enriched in waters where sediment-laden rivers enter the ocean. As such, the Ganges-Brahmaputra is likely to produce globally significant barium and [sup 226]Ra fluxes to the ocean. Water samples for barium and [sup 226]Ra were collected within four major channels of the Ganges-Brahmaputra mixing zone during a period of low sediment and freshwater discharge. The data suggest that in addition to suspended sediments supplied directly from rivers, river sediments deposited during high discharge in mangroves and on islands are desorbing barium and [sup 226]Ra to seawater. The release of barium and [sup 226]Ra from these sediment deposits is out-of-phase with the direct supply of sediments from the rivers. Estimates of the annual fluxes of barium and [sup 226]Ra from the Ganges-Brahmaputra mixing zone were also derived. The fluxes of barium and [sup 226]Ra are 5.3 [times] 10[sup 8] mol barium/yr and 9.5 [times] 10[sub 14] dpm radium/yr. The first silicate and phosphate mixing profiles for this system are reported. 29 refs., 6 figs., 3 tabs.

  12. 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.

  13. The Isoscalar Giant Dipole Resonance in {sup 20}Pb, {sup 90}Zr and the Nuclear Compressibility

    SciTech Connect (OSTI)

    Yildirim, Serbulent; Koeroglu, Ulas

    2008-11-11

    The isoscalar giant dipol resonance (ISGDR) in finite nuclei is studied within the framework of a relativistic transport approach. The excitation energies of spherical {sup 90}Zr and {sup 208}Pb nuclei are obtained for different quantum hydrodynamical Lagrangian parametrization. The sensitivity of ISGDR excitation energy on the nuclear bulk to surface properties are also investigated.

  14. Zr doped anatase supported reticulated ceramic foams for photocatalytic water purification

    SciTech Connect (OSTI)

    Plesch, G.; Vargov, M.; Vogt, U.F.; Department of Crystallography, University of Freiburg, D-79104 Freiburg ; Gorbr, M.; Jesenk, K.

    2012-07-15

    Highlights: ? Thick photocatalytic anatase films on macroporous reticulated ceramic foams. ? Alumina and aluminamullite macroporous reticulated foams as photocatalyst support. ? Zr doping significantly improves the TiO{sub 2} film activity in phenol photomineralization. ? Comparison of photocatalytic activity of thick films and powder suspensions. -- Abstract: Titanium dioxide films were deposited on macroporous reticulated Al{sub 2}O{sub 3} and aluminamullite foams with pore sizes of 15 ppi (pores per inch). Coatings were prepared from suspensions of precursor powders of Aeroxide{sup } P25 nanopowder and precipitated TiO{sub 2} by using a dip coating process. The TiO{sub 2} forms films with a thickness of ?220 ?m. The photocatalytic activity was characterized as the mineralization rate of an aqueous phenol solution under UVA irradiation by the TOC technique. Precipitated TiO{sub 2} films have nearly the same photocatalytic activity as a titania suspension, in which powder aggregates have a size comparable with the thickness of the films. Samples made of Aeroxide{sup } P25 nanopowder, in which the size of aggregates is ?0.1 ?m show higher efficiency of photodecomposition in suspensions with films. The doping of precipitated anatase with Zr(IV) in the atomic ratio Zr/Ti = 0.008 significantly improves the photocatalytic activity of the foam supported titania. Zr doped anatase films show better performance as the films prepared only from Aeroxide{sup } P25 nanopowder.

  15. The Department of Energy's American Recovery and Reinvestment Act - California State Energy Program, OAS-RA-11-10

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

    American Recovery and Reinvestment Act - California State Energy Program OAS-RA-11-10 July 2011 Department of Energy Washington, DC 20585 July 28, 2011 MEMORANDUM FOR THE ACTING ASSISTANT SECRETARY FOR ENERGY EFFICIENCY AND RENEWABLE ENERGY FROM: George W. Collard Assistant Inspector General for Audits Office of Inspector General SUBJECT: INFORMATION: Audit Report on "The Department of Energy's American Recovery and Reinvestment Act - California State Energy Program" BACKGROUND The

  16. Waste Disposal and Recovery Act Efforts at the Oak Ridge Reservation,OAS-RA-L-12-01

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

    Inspection Report Waste Disposal and Recovery Act Efforts at the Oak Ridge Reservation INS-RA-L-12-01 December 2011 Department of Energy Washington, DC 20585 December 16, 2011 MEMORANDUM FOR THE MANAGER, OAK RIDGE OFFICE FROM: Sandra D. Bruce Assistant Inspector General for Inspections Office of Inspector General SUBJECT: INFORMATION: Inspection Report on "Waste Disposal and Recovery Act Efforts at the Oak Ridge Reservation" BACKGROUND The Department of Energy's (Department) expends

  17. Structural and spectroscopic properties of high temperature prepared ZrO₂–TiO₂ mixed oxides

    SciTech Connect (OSTI)

    Gionco, Chiara; Battiato, Alfio; Vittone, Ettore; Paganini, Maria Cristina; Giamello, Elio

    2013-05-01

    ZrO₂-TiO₂ mixed oxides of various composition, with the molar fraction of TiO₂ ranging from 0.1% to 15%, have been prepared via sol-gel synthesis and then calcined at 1273 K to check both their thermal stability and physicochemical properties. These solids are usually employed in photocatalytic processes and as active phase supports in heterogeneous catalysis. As indicated by X-ray diffraction and Raman spectroscopy, solid solutions based on Ti ions diluted in the ZrO₂ matrix are formed in the whole range of Ti molar fraction examined. Materials with low Ti loading (0.1%–1%) are basically constituted by the monoclinic phase of ZrO₂ while the tetragonal phase becomes prevalent at 15% of TiO₂ molar fraction. The presence of Ti ions modify the electronic structure of the solid as revealed by investigation of the optical properties. The typical band gap transition of ZrO₂ undergoes, in fact, a red shift roughly proportional to the Ti loading which reach the remarkable value of 1.6 eV for the sample with 10% of molar Ti concentration. Comparing chemical analysis of the solids with XPS data it has been put into evidence that the titanium ions distribution into the solid is not uniform and the concentration of Ti⁴⁺ tend to be higher in subsurface layers than in the crystal bulk. The introduction of titanium ions in the structure increases the reducibility of the solid. Annealing under vacuum at various temperatures causes oxygen depletion with consequent reduction of the solid which shows up mainly in terms of formation of Ti³⁺ reduced centres which are characterized by a typical EPR signal. Ti³⁺ defects forms, as also forecast by theoretical modelling of the solid, as their energy is lower than that of other possible reduced defective centers. The reduced solids are able to transfer electrons to adsorbed oxygen molecules in mild condition resulting in the formation of surface superoxide anions (O₂⁻) which are stabilized on surface Zr

  18. 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.

  19. Addition of the Neurokinin-1-Receptor Antagonist (RA) Aprepitant to a 5-Hydroxytryptamine-RA and Dexamethasone in the Prophylaxis of Nausea and Vomiting Due to Radiation Therapy With Concomitant Cisplatin

    SciTech Connect (OSTI)

    Jahn, Franziska; Jahn, Patrick; Sieker, Frank; Vordermark, Dirk; Jordan, Karin

    2015-08-01

    Purpose: To assess, in a prospective, observational study, the safety and efficacy of the addition of the neurokinin-1-receptor antagonist (NK1-RA) aprepitant to concomitant radiochemotherapy, for the prophylaxis of radiation therapy–induced nausea and vomiting. Patients and Methods: This prospective observational study compared the antiemetic efficacy of an NK1-RA (aprepitant), a 5-hydroxytryptamine-RA, and dexamethasone (aprepitant regimen) versus a 5-hydroxytryptamine-RA and dexamethasone (control regimen) in patients receiving concomitant radiochemotherapy with cisplatin at the Department of Radiation Oncology, University Hospital Halle (Saale), Germany. The primary endpoint was complete response in the overall phase, defined as no vomiting and no use of rescue therapy in this period. Results: Fifty-nine patients treated with concomitant radiochemotherapy with cisplatin were included in this study. Thirty-one patients received the aprepitant regimen and 29 the control regimen. The overall complete response rates for cycles 1 and 2 were 75.9% and 64.5% for the aprepitant group and 60.7% and 54.2% for the control group, respectively. Although a 15.2% absolute difference was reached in cycle 1, a statistical significance was not detected (P=.22). Furthermore maximum nausea was 1.58 ± 1.91 in the control group and 0.73 ± 1.79 in the aprepitant group (P=.084); for the head-and-neck subset, 2.23 ± 2.13 in the control group and 0.64 ± 1.77 in the aprepitant group, respectively (P=.03). Conclusion: This is the first study of an NK1-RA–containing antiemetic prophylaxis regimen in patients receiving concomitant radiochemotherapy. Although the primary endpoint was not obtained, the absolute difference of 10% in efficacy was reached, which is defined as clinically meaningful for patients by international guidelines groups. Randomized phase 3 studies are necessary to further define the potential role of an NK1-RA in this setting.

  20. Y-Ba-Cu-O films prepared by a paint-on method

    SciTech Connect (OSTI)

    Shih, I.; Qiu, C.X.

    1988-02-29

    Polycrystalline films of Y-Ba-Cu-O with a thickness of about 20--40 ..mu..m have been prepared on alumina substrates using a paint-on method. The liquid source used was obtained by mixing powder of Y/sub 2/O/sub 3/, BaCO/sub 3/, and CuO in liquid triethanolamine. Several Y-Ba-Cu-O films with an onset temperature of about 100 K and a zero resistance temperature of 85 K have been obtained after a short heat treatment at 1000 /sup 0/C in flowing O/sub 2/.

  1. 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.

  2. 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.

  3. 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 3560 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 400550 ?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 3560 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.

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

    Office of Scientific and Technical Information (OSTI)

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

  5. Ba{sub 2}TeO as an optoelectronic material: First-principles study

    SciTech Connect (OSTI)

    Sun, Jifeng; Shi, Hongliang; Du, Mao-Hua; Singh, David J.; Siegrist, Theo

    2015-05-21

    The band structure, optical, and defects properties of Ba{sub 2}TeO are systematically investigated using density functional theory with a view to understanding its potential as an optoelectronic or transparent conducting material. Ba{sub 2}TeO crystallizes with tetragonal structure (space group P4/nmm) and with a 2.93 eV optical bandgap [Besara et al., J. Solid State Chem. 222, 60 (2015)]. We find relatively modest band masses for both electrons and holes suggesting applications. Optical properties show infrared-red absorption when doped. This could potentially be useful for combining wavelength filtering and transparent conducting functions. Furthermore, our defect calculations show that Ba{sub 2}TeO is intrinsically p-type conducting under Ba-poor condition. However, the spontaneous formation of the donor defects may constrain the p-type transport properties and would need to be addressed to enable applications.

  6. Fermi surfaces and phase stability of Ba( Fe 1 - x M x ) 2 As...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Fermi surfaces and phase stability of Ba( Fe 1 - x M x ) 2 As 2 ( M Co ... Resource Relation: Journal Name: Physical Review. B, Condensed Matter and Materials ...

  7. Morphology and Composition cycle of BaO/Al2O3 NSR Catalysts during...

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

    spectroscopy and microscopy study Morphology and Composition cycle of BaOAl2O3 NSR Catalysts during NO2 Uptake and Release: A multi spectroscopy and microscopy study 2005 Diesel ...

  8. Ba2TeO as an optoelectronic material: First-principles study

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

    Sun, Jifeng; Shi, Hongliang; Du, Mao-Hua; Siegrist, Theo; Singh, David J.

    2015-05-21

    The band structure, optical and defects properties of Ba2TeO are systematically investigated using density functional theory with a view to understanding its potential as an optoelectronic or transparent conducting material. Ba2TeO crystallizes with tetragonal structure (space group P4/nmm) and with a 2.93 eV optical band gap1. We find relatively modest band masses for both electrons and holes suggesting applications. Optical properties show a infrared-red absorption when doped. This could potentially be useful for combining wavelength filtering and transparent conducting functions. Furthermore, our defect calculations show that Ba2TeO is intrinsically p-type conducting under Ba-poor condition. However, the spontaneous formation of themore » donor defects may constrain the p-type transport properties and would need to be addressed to enable applications.« less

  9. The U5+ compound Ba9Ag10U4S24: Synthesis, structure, and electronic...

    Office of Scientific and Technical Information (OSTI)

    The U5+ compound Ba9Ag10U4S24: Synthesis, structure, and electronic properties This ... Sponsoring Org: USDOE Country of Publication: United States Language: English Word Cloud ...

  10. Observation in BaBar of a Narrow Resonance in the D{sub s} pi...

    Office of Scientific and Technical Information (OSTI)

    in the Dsub s pisup 0 System at 2317 MeVcsup 2 Citation Details In-Document Search Title: Observation in BaBar of a Narrow Resonance in the Dsub s pisup 0 System at ...

  11. Chiral Anomaly Effects And the BaBar Measurements of the$\\gamma...

    Office of Scientific and Technical Information (OSTI)

    ...to pi0 Transition Form Factor Citation Details In-Document Search Title: Chiral Anomaly Effects And the BaBar Measurements of the gammagamma*to pi0 ...

  12. NO2 uptake under practically relevant conditions on BaO/Pt(111)

    SciTech Connect (OSTI)

    Mudiyanselage, Kumudu K.; Szanyi, Janos

    2012-02-14

    The formation of nitrites and nitrates (Ba(NOx)2) under practically relevant conditions (PNO2 up to 1.0 Torr and T = 500 K) and their thermal decomposition on BaO (>20 monolayer equivalent (MLE))/Pt(1 1 1) were studied using temperature programmed desorption (TPD), infrared reflection absorption (IRA), and Xray photoelectron (XP) spectroscopies. The exposure of BaO to 1.0 × 10−8 Torr NO2 at 500 K leads to the formation of a Ba(NOx)2 layer with small, disordered crystalline nitrate clusters. Under these conditions (PNO2 = 1.0 × 10−8 Torr and T = 500 K) only the top portion of the BaO layer converts to Ba(NOx)2 and the nitrites in this Ba(NOx)2 layer stay without converting completely to nitrates even after 100 min of NO2 exposure. In the thermal decomposition of Ba(NOx)2, first nitrites decompose, releasing NO and then the decomposition of nitrates occurs via two pathways releasing NO2 and NO + O2. At 500 K and PNO2 ≥ 1.0 × 10−7 Torr, first NO2 reacts with BaO to form small disordered crystalline Ba(NO3)2 particles and then these particles agglomerate to form large, well-ordered (bulk-like) crystalline nitrates as the NO2 exposure increases. The thermal decomposition of these well-ordered, bulk-like crystalline nitrate aggregates occurs in two steps releasing NO2 and NO + O2 in each step in two different temperature regions. NO2 pressure ≥1.0 × 10−5 Torr is required for the complete oxidation of initially formed nitrites to nitrates and the full nitration of the BaO layer at 500 K sample temperature. We gratefully acknowledge the US Department of Energy (DOE), Office of Basic Energy Sciences, Division of Chemical Sciences for the support of this work. The research described in this paper was performed at the Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by the DOE Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory (PNNL). PNNL is operated for the US

  13. Building America Team (BA-PIRC) - 2014 BTO Peer Review | Department of

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

    Energy BA-PIRC) - 2014 BTO Peer Review Building America Team (BA-PIRC) - 2014 BTO Peer Review Presenter: Eric Martin, Florida Solar Energy Center Building America research projects develop and demonstrate market-ready building solutions that improve the energy efficiency of new and existing homes, increasing comfort, health, safety, and durability. When fully deployed, proven solutions will reduce building-related energy use in new and existing residential building stock by 30% and 25%,

  14. Crystallography and Physical Properties of BaCo2As2, Ba0.94K0.06Co2As2, and Ba0.78K0.22Co2As2

    SciTech Connect (OSTI)

    Anand, V K; Quirinale, Dante G; Lee, Yongbin; Harmon, Bruce N; Furukawa, Yuji; Ogloblichev, V V; Huq, A; Abernathy, D L; Stephens, P W; McQueeney, Robert J; Kreyssig, Aandreas; Goldman, Alan I; Johnston, David C

    2014-08-01

    The crystallographic and physical properties of polycrystalline and single crystal samples of BaCo2As2 and K-doped Ba{1-x}K{x}Co2As2 (x = 0.06, 0.22) are investigated by x-ray and neutron powder diffraction, magnetic susceptibility chi, magnetization, heat capacity Cp, {75}As NMR and electrical resistivity rho measurements versus temperature T. The crystals were grown using both Sn flux and CoAs self-flux, where the Sn-grown crystals contain 1.6-2.0 mol% Sn. All samples crystallize in the tetragonal ThCr2Si2-type structure (space group I4/mmm). For BaCo2As2, powder neutron diffraction data show that the c-axis lattice parameter exhibits anomalous negative thermal expansion from 10 to 300 K, whereas the a-axis lattice parameter and the unit cell volume show normal positive thermal expansion over this T range. No transitions in BaCo2As2 were found in this T range from any of the measurements. Below 40-50 K, we find rho ~ T^2 indicating a Fermi liquid ground state. A large density of states at the Fermi energy D(EF) ~ 18 states/(eV f.u.) for both spin directions is found from low-T Cp(T) measurements, whereas the band structure calculations give D(EF) = 8.23 states/(eV f.u.). The {75}As NMR shift data versus T have the same T dependence as the chi(T) data, demonstrating that the derived chi(T) data are intrinsic. The observed {75}As nuclear spin dynamics are consistent with the presence of ferromagnetic and/or stripe-type antiferromagnetic spin fluctuations. The crystals of Ba{0.78}K{0.22}Co2As2 were grown in Sn flux and show properties very similar to those of undoped BaCo2As2. On the other hand, the crystals from two batches of Ba{0.94}K{0.06}Co2As2 grown in CoAs self-flux show evidence of weak ferromagnetism at T < 10 K with small ordered moments at 1.8 K of 0.007 and 0.03 muB per formula unit, respectively.

  15. 137 Ba Double Gamma Decay Measurement with GAMMASPHERE

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

    Merchán, E.; Moran, K.; Lister, C. J.; Chowdhury, P.; McCutchan, E. A.; Greene, J. P.; Zhu, S.; Lauritsen, T.; Carpenter, M. P.; Shearman, R.

    2015-05-28

    The study of the electromagnetic moments (EM), and decay probability, provides detailed information about nuclear wave functions. The well-know properties of EM interactions are good for extracting information about the motion of nucleons. Higher order EM processes always occur, but are usually too weak to be measured. In the case of a 0+ → 0+ transitions, where a single gamma transition is forbidden, the simultaneous emission of two γ-rays has been studied. An interesting opportunity to further investigate 2-photon emission phenomena is by using a standard 137Cs source populating, via β-decay, the Jπ = 11/2- isomeric state at 662 keVmore » in 137Ba. In this case, two photon process can have contributions from quadrupole-quadrupole or dipole-octupole multipolarities in direct competition with the high multipolarity M4 decay. Since the yield of the double gamma decay is around six orders of magnitude less than the first order transition, very good statistics are needed in order to observe the phenomena and great care must be taken to suppress the first-order decay. The Gammasphere array is ideal since its configuration allows a good coverage of the angular distribution and the Compton events can be suppressed. Nevertheless the process to understand and eliminate the Compton background is a challenge. Geant4 simulations were carried out to help understand and correct for those factors.« less

  16. 137 Ba Double Gamma Decay Measurement with GAMMASPHERE

    SciTech Connect (OSTI)

    Merchn, E.; Moran, K.; Lister, C. J.; Chowdhury, P.; McCutchan, E. A.; Greene, J. P.; Zhu, S.; Lauritsen, T.; Carpenter, M. P.; Shearman, R.

    2015-05-28

    The study of the electromagnetic moments (EM), and decay probability, provides detailed information about nuclear wave functions. The well-know properties of EM interactions are good for extracting information about the motion of nucleons. Higher order EM processes always occur, but are usually too weak to be measured. In the case of a 0+ ? 0+ transitions, where a single gamma transition is forbidden, the simultaneous emission of two ?-rays has been studied. An interesting opportunity to further investigate 2-photon emission phenomena is by using a standard 137Cs source populating, via ?-decay, the J? = 11/2- isomeric state at 662 keV in 137Ba. In this case, two photon process can have contributions from quadrupole-quadrupole or dipole-octupole multipolarities in direct competition with the high multipolarity M4 decay. Since the yield of the double gamma decay is around six orders of magnitude less than the first order transition, very good statistics are needed in order to observe the phenomena and great care must be taken to suppress the first-order decay. The Gammasphere array is ideal since its configuration allows a good coverage of the angular distribution and the Compton events can be suppressed. Nevertheless the process to understand and eliminate the Compton background is a challenge. Geant4 simulations were carried out to help understand and correct for those factors.

  17. Measurements of the CKM Angle Alpha at BaBar

    SciTech Connect (OSTI)

    Stracka, Simone; /Milan U. /INFN, Milan

    2012-04-04

    The authors present improved measurements of the branching fractions and CP-asymmetries fin the B{sup 0} {yields} {pi}{sup +}{pi}{sup -}, B{sup 0} {yields} {pi}{sup 0}{pi}{sup 0}, and B{sup +} {yields} {rho}{sup +}{rho}{sup 0} decays, which impact the determination of {alpha}. The combined branching fractions of B {yields} K{sub 1}(1270){pi} and B {yields} K{sub 1}(1400){pi} decays are measured for the first time and allow a novel determination of {alpha} in the B{sup 0} {yields} {alpha}{sub 1}(1260){sup {+-}}{pi}{sup {-+}} decay channel. These measurements are performed using the final dataset collected by the BaBar detector at the PEP-II B-factory. The primary goal of the experiments based at the B factories is to test the Cabibbo-Kobayashi-Maskawa (CKM) picture of CP violation in the standard model of electroweak interactions. This can be achieved by measuring the angles and sides of the Unitarity Triangle in a redundant way.

  18. Synthesis and physicochemical properties of Zr-MCM-41 mesoporous molecular sieves and Pt/H{sub 3}PW{sub 12}O{sub 40}/Zr-MCM-41 catalysts

    SciTech Connect (OSTI)

    Chen, L.F. Wang, J.A.; Norena, L.E.; Aguilar, J.; Navarrete, J.; Salas, P.; Montoya, J.A.; Del Angel, P.

    2007-10-15

    For the first time, modifications of the surface and framework of Si-MCM-41 by depositing a heteropolyacid on the surface and by introducing foreign Zr{sup 4+} ions into the framework are investigated. The Zr-modified Si-MCM-41 mesoporous materials (hereafter referred as WSZn, n=Si/Zr=25, 15, 8, 4) were synthesized through a surfactant-templated preparation approach, using low-cost fumed silica as the Si precursor. After impregnation with 25 wt% of H{sub 3}PW{sub 12}O{sub 40}, the surface Broensted acidity of the Pt/H{sub 3}PW{sub 12}O{sub 40}/WSZn catalysts was greatly enhanced by 2-10 times relative to the bare WSZn support. Two kinds of supported heteropolyacids were formed: (i) bulk-like heteropolyacid crystals with unchanged Keggin structures, and (ii) highly dispersed heteropolyacid with distorted Keggin units. The formation of various kinds of heteropolyacid structures is closely related to the interaction between the heteropolyanions and the hydroxyl groups in the host support. - Graphical abstract: Modifications of the surface and framework of Si-MCM-41 by depositing a heteropolyacid on the surface and by introducing foreign Zr{sup 4+} ions into the framework are investigated. Broensted acidity of the Pt/H{sub 3}PW{sub 12}O{sub 40}/Zr-MCM-41 catalysts was greatly enhanced by 2-10 times relative to the bare Zr-MCM-41 support.

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

    SciTech Connect (OSTI)

    Hgberg, 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 5.57 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 0.120.18 to compare with the range of 0.40.6 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 ?100120 ?? cm for the ?-ZrH{sub 2} films, which is slightly higher compared to Zr films with values in the range 7080 ?? cm.

  20. 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.

  1. 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 ZrEr 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 ZrEr 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.

  2. Atomic disorder in Gd{sub 2}Zr{sub 2}O{sub 7} pyrochlore

    SciTech Connect (OSTI)

    Zhang, F. X.; Lang, M.; Ewing, R. C.

    2015-05-11

    Gd{sub 2}Zr{sub 2}O{sub 7} pyrochlore with different degrees of cation disorder were synthesized by isothermal annealing at various temperatures (1100–1550 °C), and the related changes in the structure were investigated by ambient and high pressure x-ray diffraction (XRD) measurements. Unit cell parameters increase almost linearly with increasing treatment temperature. The degree of cation order in pyrochlore also increases with the increase of temperature, but saturates at ∼60%. The compressibility of the pyrochlore structures decreases when the degree of cation order increases. High pressure XRD measurements also indicate that the phase stability of Gd{sub 2}Zr{sub 2}O{sub 7} is not very sensitive to the degree of atomic disorder in the pyrochlore structure.

  3. Unique properties of CuZrAl bulk metallic glasses induced by microalloying

    SciTech Connect (OSTI)

    Huang, B.; Bai, H. Y.; Wang, W. H.

    2011-12-15

    We studied the glass forming abilities (GFA), mechanical, and physical properties of (CuZr){sub 92.5}Al{sub 7}X{sub 0.5} (X = La, Sm, Ce, Gd, Ho, Y, and Co) bulk metallic glasses (BMGs). We find that the GFA, mechanical, and physical properties can be markedly changed and modulated by the minor rare earth addition. The Kondo screening effect is found to exist in (CuZr){sub 92.5}Al{sub 7}Ce{sub 0.5} BMG at low temperatures and the Schottky effect exists in all the rare earth element doped BMGs. Our results indicate that the minor addition is an effective way for modulating and getting desirable properties of the BMGs. The mechanisms of the effects of the addition are discussed. The results have implications for the exploration of metallic glasses and for improving the mechanical and low temperature physical properties of BMGs.

  4. 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

  5. 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.

  6. DOE/RA/50354 Volume II FEAS)IBILITY STUDY FOR A 10 MM GPY FUEL ETHANOL PLANT

    Office of Scientific and Technical Information (OSTI)

    DOE/RA/50354 Volume II FEAS)IBILITY STUDY FOR A 10 MM GPY FUEL ETHANOL PLANT BRADY HOT SPRINGS, NEVADA . Volume II - Geothermal Resource, Agricultural Feedstock, Markets and E c o q h i c Viability 8 *e _. - - * 7 , - - - September 1980 i Prepared by Geothermal Food Processors, Inc. Fernley, Nevada and The Andersen Group DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency Thereof,

  7. High strength Sn-Mo-Nb-Zr alloy tubes and method of making same

    DOE Patents [OSTI]

    Cheadle, Brian A.

    1977-01-01

    Tubes for use in nuclear reactors fabricated from a quaternary alloy comprising 2.5-4.0 wt% Sn, 0.5-1.5 wt% Mo, 0.5-1.5 wt% Nb, balance essentially Zr. The tubes are fabricated by a process of hot extrusion, heat treatment, cold working to size and age hardening, so as to produce a microstructure comprising elongated .alpha. grains with an acicular transformed .beta. grain boundary phase.

  8. Separate effects identification via casting process modeling for experimental measurement of UPuZr 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 UPuZr 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.

  9. Infrared spectroscopy of CaTiO3, SrTiO3, BaTiO3, Ba0.5Sr0.5TiO3...

    Office of Scientific and Technical Information (OSTI)

    Infrared spectroscopy of CaTiO3, SrTiO3, BaTiO3, Ba0.5Sr0.5TiO3 thin films, and (BaTiO3)5(SrTiO3)5 superlattice grown on SrRuO3SrTiO3(001) substrates Citation Details In-Document ...

  10. 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.

  11. Growth and oxidization stability of cubic Zr{sub 1−x}Gd{sub x}N solid solution thin films

    SciTech Connect (OSTI)

    Höglund, C.; Alling, B.; Jensen, J.; Hultman, L.; Birch, J.; Hall-Wilton, R.

    2015-05-21

    We report Zr{sub 1−x}Gd{sub x}N thin films deposited by magnetron sputter deposition. We show a solid solubility of the highly neutron absorbing GdN into ZrN along the whole compositional range, which is in excellent agreement with our recent predictions by first-principles calculations. An oxidization study in air shows that Zr{sub 1−x}Gd{sub x}N with x reaching from 1 to close to 0 fully oxidizes, but that the oxidization is slowed down by an increased amount of ZrN or stopped by applying a capping layer of ZrN. The crystalline quality of Zr{sub 0.5}Gd{sub 0.5}N films increases with substrate temperatures increasing from 100 °C to 900 °C.

  12. Optical and local structural study of Gd doped ZrO{sub 2} thin films deposited by RF magnetron sputtering technique

    SciTech Connect (OSTI)

    Haque, S. Maidul Shinde, D. D.; Misal, J. S.; Jha, S. N.; Bhattacharyya, D.; Sahoo, N. K.

    2015-06-24

    ZrO{sub 2} samples with 0, 7, 9, 11, 13 % Gd doping have been prepared by RF magnetron sputtering deposition technique for solid oxide fuel cell application. The optical properties of the samples have been studied by transmission spectrophotometry and spectroscopic ellipsometry while the local structure surrounding Zr sites has been characterized by extended x-ray absorption fine structure (EXAFS) measurement at Zr K edge with synchrotron radiation. It has been observed that beyond 11% Gd doping, band gap decreases and refractive index increases significantly and also oxygen and Zr coordinations surrounding Zr sites increase which indicates the formation of Gd clustering in ZrO{sub 2} matrix beyond this doping concentration.

  13. Work Function Reduction by BaO: Growth of Crystalline Barium Oxide on Ag(001) and Ag(111) Surfaces

    SciTech Connect (OSTI)

    Droubay, Timothy C.; Kong, Lingmei; Chambers, Scott A.; Hess, Wayne P.

    2015-02-01

    Ultrathin films of barium oxide were grown on Ag(001) and Ag(111) using the evaporation of Ba metal in an O2 atmosphere by molecular beam epitaxy. Ultraviolet photoemission spectroscopy reveals that films consisting of predominantly BaO or BaO2 result in Ag(001) work function reductions of 1.74 eV and 0.64 eV, respectively. On the Ag(001) surface, Ba oxide growth is initiated by two-dimensional nucleation of epitaxial BaO, followed by a transition to three-dimensional dual-phase nucleation of epitaxial BaO and BaO2. Three-dimensional islands of primarily BaO2(111) nucleate epitaxially on the Ag(111) substrate leaving large patches of Ag uncovered. We find no indication of chemical reaction or charge transfer between the films and the Ag substrates. These data suggest that the origin of the observed work function reduction is largely due to a combination of BaO surface relaxation and an electrostatic compressive effect.

  14. Significant increase of Curie temperature in nano-scale BaTiO{sub 3}

    SciTech Connect (OSTI)

    Li, Yueliang; Liao, Zhenyu; Fang, Fang; Zhu, Jing; Wang, Xiaohui; Li, Longtu

    2014-11-03

    The low Curie temperature (T{sub c}?=?130?C) of bulk BaTiO{sub 3} greatly limits its applications. In this work, the phase structures of BaTiO{sub 3} nanoparticles with sizes ranging from 2.5?nm to 10?nm were studied at various temperatures by using aberration-corrected transmission electron microscopy (TEM) equipped with an in-situ heating holder. The results implied that each BaTiO{sub 3} nanoparticle was composed of different phases, and the ferroelectric ones were observed in the shells due to the complicated surface structure. The ferroelectric phases in BaTiO{sub 3} nanoparticles remained at 600?C, suggesting a significant increase of T{sub c}. Based on the in-situ TEM results and the data reported by others, temperature-size phase diagrams for BaTiO{sub 3} particles and ceramics were proposed, showing that the phase transition became diffused and the T{sub c} obviously increased with decreasing size. The present work sheds light on the design and fabrication of advanced devices for high temperature applications.

  15. Lattice dynamics of BaFe2X3(X=S,Se) compounds

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

    Popović, Z. V.; Šćepanović, M.; Lazarević, N.; Opačić, M.; Radonjić, M. M.; Tanasković, D.; Lei, Hechang; Petrovic, C.

    2015-02-27

    We present the Raman scattering spectra of the S=2 spin ladder compounds BaFe₂X₃ (X=S,Se) in a temperature range between 20 and 400 K. Although the crystal structures of these two compounds are both orthorhombic and very similar, they are not isostructural. The unit cell of BaFe₂S₃ (BaFe₂Se₃) is base-centered Cmcm (primitive Pnma), giving 18 (36) modes to be observed in the Raman scattering experiment. We have detected almost all Raman active modes, predicted by factor group analysis, which can be observed from the cleavage planes of these compounds. Assignment of the observed Raman modes of BaFe₂S(Se)₃ is supported by themore » lattice dynamics calculations. The antiferromagnetic long-range spin ordering in BaFe₂Se₃ below TN=255K leaves a fingerprint both in the A1g and B3g phonon mode linewidth and energy.« less

  16. Investigation of the {sup 128}Ba nucleus with the (p,t) reaction

    SciTech Connect (OSTI)

    Pascu, S.; Cata-Danil, Gh.; Bucurescu, D.; Marginean, N.; Zamfir, N. V.; Graw, G.; Gollwitzer, A.; Hofer, D.; Valnion, B. D.

    2009-06-15

    The low lying states in {sup 128}Ba have been investigated for the first time with the {sup 130}Ba(p,t){sup 128}Ba reaction. The experiment was performed at the Munich Q3D magnetic spectrograph with a 25-MeV proton beam and a high-resolution, 1.5-m-long focal plane detector. As a result of this experiment 27 excited levels with energies below 3.7 MeV have been observed for the first time, significantly increasing (by {approx}50%) the number of levels observed in {sup 128}Ba. Angular distributions of tritons were measured and their comparison with the distorted wave Born approximation calculation allowed in most cases spin and parity assignments for the nuclear levels. The experimental two-neutron transition strengths with transferred angular momentum L=0 and 2 are compared with the predictions of the IBA-1 model with a new set of parameters. The results indicate for the first time from a hadronic probe perspective a transitional structure close to the O(6) symmetry for the {sup 128}Ba nucleus, confirming previous conclusions of {gamma}-ray spectroscopy studies.

  17. Microstructure and Cs Behavior of Ba-Doped Aluminosilicate Pollucite Irradiated with F+ Ions

    SciTech Connect (OSTI)

    Jiang, Weilin; Kovarik, Libor; Zhu, Zihua; Varga, Tamas; Engelhard, Mark H.; Bowden, Mark E.; Nenoff, Tina M.; Garino, Terry

    2014-08-07

    Radionuclide 137Cs is one of the major fission products that dominate heat generation in spent fuels over the first 300 hundred years. A durable waste form for 137Cs that decays to 137Ba is needed to minimize its environmental impact. Aluminosilicate pollucite CsAlSi2O6 is selected as a model waste form to study the decay-induced structural effects. While Ba-containing precipitates are not present in charge-balanced Cs0.9Ba0.05AlSi2O6, they are found in Cs0.9Ba0.1AlSi2O6 and identified as monoclinic Ba2Si3O8. Pollucite is susceptible to electron irradiation induced amorphization. The threshold density of the electronic energy deposition for amorphization is determined to be ~235 keV/nm3. Pollucite can be readily amorphized under F+ ion irradiation at 673 K. A significant amount of Cs diffusion and release from the amorphized pollucite is observed during the irradiation. However, cesium is immobile in the crystalline structure under He+ ion irradiation at room temperature. The critical temperature for amorphization is not higher than 873 K under F+ ion irradiation. If kept at or above 873 K all the time, the pollucite structure is unlikely to be amorphized; Cs diffusion and release are improbable. A general discussion regarding pollucite as a potential waste form is provided in this report.

  18. Hybrid molecular beam epitaxy for the growth of stoichiometric BaSnO{sub 3}

    SciTech Connect (OSTI)

    Prakash, Abhinav Dewey, John; Yun, Hwanhui; Jeong, Jong Seok; Mkhoyan, K. Andre; Jalan, Bharat

    2015-11-15

    Owing to its high room-temperature electron mobility and wide bandgap, BaSnO{sub 3} has recently become of significant interest for potential room-temperature oxide electronics. A hybrid molecular beam epitaxy (MBE) approach for the growth of high-quality BaSnO{sub 3} films is developed in this work. This approach employs hexamethylditin as a chemical precursor for tin, an effusion cell for barium, and a radio frequency plasma source for oxygen. BaSnO{sub 3} films were thus grown on SrTiO{sub 3} (001) and LaAlO{sub 3} (001) substrates. Growth conditions for stoichiometric BaSnO{sub 3} were identified. Reflection high-energy electron diffraction (RHEED) intensity oscillations, characteristic of a layer-by-layer growth mode were observed. A critical thickness of ∼1 nm for strain relaxation was determined for films grown on SrTiO{sub 3} using in situ RHEED. Scanning transmission electron microscopy combined with electron energy-loss spectroscopy and energy dispersive x-ray spectroscopy confirmed the cube-on-cube epitaxy and composition. The importance of precursor chemistry is discussed in the context of the MBE growth of BaSnO{sub 3}.

  19. 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.

  20. Ba2TeO: A new layered oxytelluride

    SciTech Connect (OSTI)

    Besara, T.; Ramirez, D.; Sun, J.; Whalen, J. B.; Tokumoto, T. D.; McGill, S. A.; Singh, D. J.; Siegrist, T.

    2015-02-01

    For single crystals of the new semiconducting oxytelluride phase, Ba2TeO, we synthesized from barium oxide powder and elemental tellurium in a molten barium metal flux. Ba2TeO crystallizes in tetragonal symmetry with space group P4/nmm (#129), a=5.0337(1) Å, c=9.9437(4) Å, Z=2. The crystals were characterized by single crystal x-ray diffraction, heat capacity and optical measurements. Moreover, the optical measurements along with electronic band structure calculations indicate semiconductor behavior with a band gap of 2.93 eV. Resistivity measurements show that Ba2TeO is highly insulating.

  1. High-mobility BaSnO{sub 3} grown by oxide molecular beam epitaxy

    SciTech Connect (OSTI)

    Raghavan, Santosh; Schumann, Timo; Kim, Honggyu; Zhang, Jack Y.; Cain, Tyler A.; Stemmer, Susanne

    2016-01-01

    High-mobility perovskite BaSnO{sub 3} films are of significant interest as new wide bandgap semiconductors for power electronics, transparent conductors, and as high mobility channels for epitaxial integration with functional perovskites. Despite promising results for single crystals, high-mobility BaSnO{sub 3} films have been challenging to grow. Here, we demonstrate a modified oxide molecular beam epitaxy (MBE) approach, which supplies pre-oxidized SnO{sub x}. This technique addresses issues in the MBE of ternary stannates related to volatile SnO formation and enables growth of epitaxial, stoichiometric BaSnO{sub 3}. We demonstrate room temperature electron mobilities of 150 cm{sup 2} V{sup −1} s{sup −1} in films grown on PrScO{sub 3}. The results open up a wide range of opportunities for future electronic devices.

  2. Structural, negative thermal expansion and photocatalytic properties of ZrV{sub 2}O{sub 7}: a comparative study between fibers and powders

    SciTech Connect (OSTI)

    Liu, Qinqin; Yang, Juan; Rong, Xiaoqing; Sun, Xiujuan; Cheng, Xiaonong; Tang, Hua; Li, Haohua

    2014-10-15

    Novel ZrV{sub 2}O{sub 7} microfibers with diameters about 13 ?m were synthesized using a solgel technique. For comparison, ZrV{sub 2}O{sub 7} powders were prepared by the same method. The resultant structures were studied by X-ray diffraction, field-emission scanning electron microscopy and transmission electron microscopy. The results indicated that both the pure ZrV{sub 2}O{sub 7} microfibers and powders could be synthesized by the solgel technique. The thermal expansion property of the as-prepared ZrV{sub 2}O{sub 7} microfibers and powders was characterized by a thermal mechanical analyzer, both the fibers with cylindrical morphology and irregular powders with average size between 100 and 200 nm showed negative thermal expansion between 150 C and 600 C. The photocatalytic activity of the microfibers was compared to that of powders under UV radiations. The band gap of ZrV{sub 2}O{sub 7} microfibers decreased and its absorption edge exhibited red shift. The microfibers also had a higher surface area compared with the powders, resulting in considerably higher photocatalytic characteristics. The large surface area and the enhanced photocatalytic activity of the ZrV{sub 2}O{sub 7} microfibers also offer potential applications in sensors and inorganic ion exchangers. - Graphical abstract: (a and c) SEM photos of ZrV{sub 2}O{sub 7} powders and fibers. (b and d) TEM images of ZrV{sub 2}O{sub 7} powders and fibers. (e) Thermal expansion curves of ZrV{sub 2}O{sub 7} powders and fibers. (f) Degradation curves of ZrV{sub 2}O{sub 7} powders and ZrV{sub 2}O{sub 7} fibers. - Highlights: Novel ZrV{sub 2}O{sub 7} fibers could be synthesized using solgel technique. ZrV{sub 2}O{sub 7} powders with irregular shape are also prepared for comparison. Both ZrV{sub 2}O{sub 7} microfibers and powders exhibit negative thermal expansion property. ZrV{sub 2}O{sub 7} microfibers show outstanding photocatalytic activity under UV irradiation. This synthesis technique can be

  3. Anisotropy of the solid–liquid interface properties of the Ni–Zr B33 phase from molecular dynamics simulation

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

    Wilson, S. R.; Mendelev, M. I.

    2015-01-08

    Solid–liquid interface (SLI) properties of the Ni–Zr B33 phase were determined from molecular dynamics simulations. In order to perform these measurements, a new semi-empirical potential for Ni–Zr alloy was developed that well reproduces the material properties required to model SLIs in the Ni50.0Zr50.0 alloy. In particular, the developed potential is shown to provide that the solid phase emerging from the liquid Ni50.0Zr50.0alloy is B33 (apart from a small fraction of point defects), in agreement with the experimental phase diagram. The SLI properties obtained using the developed potential exhibit an extraordinary degree of anisotropy. It is observed that anisotropies in bothmore » the interfacial free energy and mobility are an order of magnitude larger than those measured to date in any other metallic compound. Moreover, the [0 1 0] interface is shown to play a significant role in the observed anisotropy. Our data suggest that the [0 1 0] interface simultaneously corresponds to the lowest mobility, the lowest free energy and the highest stiffness of all inclinations in B33 Ni–Zr. This finding can be understood by taking into account a rather complicated crystal structure in this crystallographic direction.« less

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

    SciTech Connect (OSTI)

    Stefanini, A. M.; Montagnoli, G.; Esbensen, H.; Corradi, L.; Courtin, S.; Fioretto, E.; Goasduff, A.; Grebosz, J.; Haas, F.; Mazzocco, M.; Michelagnoli, C.; Mijatović, T.; Montanari, D.; Pasqualato, G.; Parascandolo, C.; Scarlassara, F.; Strano, E.; Szilner, S.; Toniolo, N.; Torresi, D.

    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 hindrance 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.

  5. Enhancing low-temperature activity and durability of Pd-based diesel oxidation catalysts using ZrO2 supports

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

    Kim, Mi -Young; Kyriakidou, Eleni A.; Choi, Jae -Soon; Toops, Todd J.; Binder, Andrew J.; Thomas, Cyril; Schwartz, Viviane; Chen, Jihua; Hensley, Dale K.; Parks, II, James E.

    2016-01-18

    In this study, we investigated the impact of ZrO2 on the performance of palladium-based oxidation catalysts with respect to low-temperature activity, hydrothermal stability, and sulfur tolerance. Pd supported on ZrO2 and SiO2 were synthesized for a comparative study. Additionally, in an attempt to maximize the ZrO2 surface area and improve sulfur tolerance, a Pd support with ZrO2-dispersed onto SiO2 was studied. The physicochemical properties of the catalysts were examined using ICP, N2 sorption, XRD, SEM, TEM, and NH3-, CO2-, and NOx-TPD. The activity of the Pd catalysts were measured from 60 to 600 °C in a flow of 4000 ppmmore » CO, 500 ppm NO, 1000 ppm C3H6, 4% O2, 5% H2O, and Ar balance. The Pd catalysts were evaluated in fresh, sulfated, and hydrothermally aged states. Overall, the ZrO2-containing catalysts showed considerably higher CO and C3H6 oxidation activity than Pd/SiO2 under the reaction conditions studied.« less

  6. Developing 226Ra and 227Ac age-dating techniques for nuclear forensics to gain insight from concordant and non-concordant radiochronometers

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

    Kayzar, Theresa M.; Williams, Ross W.

    2015-09-26

    The model age or ‘date of purification’ of a nuclear material is an important nuclear forensic signature. In this study, chemical separation and MC-ICP-MS measurement techniques were developed for 226 Ra and 227Ac: grand-daughter nuclides in the 238U and 235U decay chains respectively. The 230Th-234U, 226Ra-238U, 231Pa-235U, and 227Ac-235U radiochronometers were used to calculate model ages for CRM-U100 standard reference material and two highly-enriched pieces of uranium metal from the International Technical Working Group Round Robin 3 Exercise. In conclusion, the results demonstrate the accuracy of the 226Ra-238U and 227Ac-235U chronometers and provide information about nuclide migration during uranium processing.

  7. Synthesis and characterization of hollow mesoporous BaFe12O19 spheres

    SciTech Connect (OSTI)

    Xu, X; Park, J; Hong, YK; Lane, AM

    2015-02-01

    A facile method is reported to synthesize hollow mesoporous BaFe12O19 spheres using a template-free chemical etching process. Hollow BaFe12O19 spheres were synthesized by conventional spray pyrolysis. The mesoporous structure is achieved by alkaline ethylene glycol etching at 185 degrees C, with the porosity controlled by the heating time. The hollow porous structure is confirmed by SEM, TEM, and FIB-FESEM characterization. The crystal structure and magnetic properties are not significantly affected after the chemical etching process. The formation mechanism of the porous structure is explained by grain boundary etching. (C) 2014 Elsevier Inc. All rights reserved.

  8. Crystal structures and phase transitions in Ba{sub 2}HoTaO{sub 6}

    SciTech Connect (OSTI)

    Kennedy, Brendan J. Saines, Paul J.; Kubota, Yoshiki; Minakata, Chiharu; Hano, Hiroko; Kato, Kenichi; Takata, Masaki

    2007-11-06

    The structure of the cation-ordered double perovskite Ba{sub 2}HoTaO{sub 6} was examined using synchrotron X-ray powder diffraction at fine temperature intervals over the range of 90-300 K. Ba{sub 2}HoTaO{sub 6} has a cubic structure in space group Fm3-barm at room temperature. A proper ferroelastic phase transition to I4/m tetragonal symmetry occurs near approximately 260 K. Analysis of the spontaneous tetragonal strain versus temperature indicated that the phase transition is second order in nature.

  9. Electron-hole asymmetry, Dirac fermions, and quantum magnetoresistance in BaMnBi2

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

    Li, Lijun; Wang, Kefeng; Graf, D.; Wang, Limin; Wang, Aifeng; Petrovic, C.

    2016-03-28

    Here, we report two-dimensional quantum transport and Dirac fermions in BaMnBi2 single crystals. BaMnBi2 is a layered bad metal with highly anisotropic conductivity and magnetic order below 290 K. Magnetotransport properties, nonzero Berry phase, small cyclotron mass, and the first-principles band structure calculations indicate the presence of Dirac fermions in Bi square nets. Quantum oscillations in the Hall channel suggest the presence of both electron and hole pockets, whereas Dirac and parabolic states coexist at the Fermi level.

  10. Spin-driven multiferroics in BaYFeO{sub 4}

    SciTech Connect (OSTI)

    Cong, Jun-Zhuang; Shen, Shi-Peng; Chai, Yi-Sheng; Yan, Li-Qin; Shang, Da-Shan; Wang, Shou-Guo; Sun, Young

    2015-05-07

    We report on the spin-driven multiferroic property and magnetoelectric effect in the lately synthesized compound BaYFeO{sub 4}. Due to its peculiar crystal structure, the system exhibits complex magnetic phases with multiple transitions. The dielectric and pyroelectric measurements evidence a spin-driven multiferroic state raised by the cycloidal spin structure below T{sub 1} = 36 K. Strong magnetoelectric effect has also been observed in the multiferroic state. The origin of noncollinear cycloidal spin structure in BaYFeO{sub 4} is believed to arise from the interactions between low-dimensional magnetic columns.

  11. The luminescence of BaF{sub 2} nanoparticles upon high-energy excitation

    SciTech Connect (OSTI)

    Vistovskyy, V. V. Zhyshkovych, A. V.; Halyatkin, O. O.; Voloshinovskii, A. S.; Mitina, N. E.; Zaichenko, A. S.; Rodnyi, P. A.; Vasil'ev, A. N.; Gektin, A. V.

    2014-08-07

    The dependence of X-ray excited luminescence intensity on BaF{sub 2} nanoparticle size was studied. A sharp decrease of self-trapped exciton luminescence intensity was observed when the nanoparticle size is less than 80?nm. The main mechanism of the luminescence quenching is caused by the escape of electrons from the nanoparticles. Escape of electrons from nanoparticles is confirmed by the considerable increase of luminescence intensity of the polystyrene scintillator with embedded BaF{sub 2} nanoparticles comparing with pure polystyrene scintillator.

  12. Fermi surfaces and phase stability of Ba(Fe1 xMx)2As2 (M = Co...

    Office of Scientific and Technical Information (OSTI)

    Fermi surfaces and phase stability of Ba(Fe1 xMx)2As2 (M Co,Ni,Cu,Zn) Citation Details In-Document Search Title: Fermi surfaces and phase stability of Ba(Fe1 xMx)2As2 (M ...

  13. Fermi surfaces and Phase Stability of Ba(Fe1-xMx))2As2 (M=Co...

    Office of Scientific and Technical Information (OSTI)

    Fermi surfaces and Phase Stability of Ba(Fe1-xMx))2As2 (MCo, Ni, Cu, Zn) Citation Details In-Document Search Title: Fermi surfaces and Phase Stability of Ba(Fe1-xMx))2As2 (MCo,...

  14. High-pressure densified solid solutions of alkaline earth hexaborides (Ca/Sr, Ca/Ba, Sr/Ba) and their high-temperature thermoelectric properties

    SciTech Connect (OSTI)

    Gürsoy, M.; Takeda, M.; Albert, B.

    2015-01-15

    Solid solutions of alkaline earth hexaborides were synthesized and densified by spark plasma sintering at 100 MPa. The high-temperature thermoelectric properties (Seebeck coefficients, electrical and thermal diffusivities, heat capacities) were measured between room temperature and 1073 K. CaB{sub 6}, SrB{sub 6}, BaB{sub 6} and the ternary hexaborides Ca{sub x}Sr{sub 1−x}B{sub 6}, Ca{sub x}Ba{sub 1−x}B{sub 6}, Sr{sub x}Ba{sub 1−x}B{sub 6} (x = 0.25, 0.5, 0.75) are n-type conducting compounds over the whole compositional and thermal ranges. The values of the figure of merit ZT for CaB{sub 6} (ca. 0.3 at 1073 K) were found to be significantly increased compared to earlier investigations which is attributed to the densification process. - Highlights: • Solid solutions of alkaline earth hexaborides were synthesized. • High-temperature thermoelectric properties of mixed calcium borides are excellent. • Spark plasma source densification results in high ZT values. • Borides are rare-earth free and refractory materials.

  15. Zr{sub 9}Co{sub 2}P{sub 4} and Zr{sub 9}Ni{sub 2}P{sub 4}: A new 3D structure type, consisting of edge- and vertex-condensed Zr{sub 6} octahedra

    SciTech Connect (OSTI)

    Kleinke, H.; Franzen, H.F.

    1996-08-28

    The isostructural title compounds were synthesized by arc-melting of stoichiometric ratios of ZrP, Zr, and Co and Ni, respectively, and subsequent annealing at 1450 {degrees}C. Their crystal structure (space group P4/mbm; Zr{sub 9-}Co{sub 2}P{sub 4}, a = 532.23(5) {angstrom}{sup 3}, Z = 2) is derived from a three-dimensional network of Zr{sub 6} octahedra. These octahedra are connected via common vertices to form chains parallel to the c axis and via common edges and vertices in the ab plane, resulting in one double chain and one single chain. Both kinds of the interstitial atoms, the iron-group-metal atom and the phosphorus, are situated in trigonal prismatic holes between these chains, forming short M-P and M-M{prime} bonds. These octahedra can be described as being of the M{sub 6}X{sub 8} cluster type as is also observed in the chalcogenide Chevrel phases. Due to the electronically nonsaturated character of the Zr octahedra and their three-dimensional connectivity, three-dimensional metallic properties are expected for both phosphides, and metallic behavior is confirmed by the observation of Pauli paramagnetism for both compounds.

  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. Study of the R-(Zr,W)-(O,N) (R = Y, Nd, Sm, Gd, Yb) oxynitride system

    SciTech Connect (OSTI)

    Tessier, Franck; Maillard, Pascal; Orhan, Emmanuelle; Chevire, Francois

    2010-02-15

    The replacement of tantalum by the couple Zr/W within the RTa-O-N systems (R = Y, Nd, Sm, Gd, Yb), enables the preparation of novel oxide and oxynitride phases in the R-Zr-W-O-N system. R{sub 2}Zr{sub 2-x}W{sub x}O{sub 7+x} oxides exhibit the fluorite-type (x < 0.9) and scheelite (x {approx} 1) structures. Corresponding oxynitride compositions are of the fluorite-type and show different colors, for example in the case of ytterbium: pale yellow (x = 0.2 or 0.25), green (x = 0.5-0.8) and brown for the tungsten-rich samples (x = 0.9, 1). Photocatalytic activity measurements have been performed to investigate the overall water splitting behavior of these colored phases.

  19. 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.

  20. 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.

  1. 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.

  2. Ab-initio study of high temperature lattice dynamics of BCC zirconium (β-Zr) and uranium (γ-U)

    SciTech Connect (OSTI)

    Ghosh, Partha S. Arya, A. Dey, G. K.

    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 β-Zr match excellently with experimental PDC. But the calculated PDC for γ-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.

  3. Synthesis and Structure Determination of Ferromagnetic Semiconductors LaAMnSnO6 (A = Sr Ba)

    SciTech Connect (OSTI)

    T Yang; T Perkisas; J Hadermann; M Croft; A Ignatov; M Greenblatt

    2011-12-31

    LaAMnSnO{sub 6} (A = Sr, Ba) have been synthesized by high temperature solid-state reactions under dynamic 1% H{sub 2}/Ar flow. Rietveld refinements on room temperature powder X-ray diffraction data indicate that LaSrMnSnO{sub 6} crystallizes in the GdFeO{sub 3}-structure, with space group Pnma and, combined with transmission electron microscopy, LaBaMnSnO{sub 6} in Imma. Both space groups are common in disordered double-perovskites. The Mn{sup 3+} and Sn{sup 4+} ions whose valence states were confirmed by X-ray absorption spectroscopy, are completely disordered over the B-sites and the BO{sub 6} octahedra are slightly distorted. LaAMnSnO{sub 6} are ferromagnetic semiconductors with a T{sub C} = 83 K for the Sr- and 66 K for the Ba-compound. The title compounds, together with the previously reported LaCaMnSnO{sub 6} provide an interesting example of progression from Pnma to Imma as the tolerance factor increases. An analysis of the relationship between space group and tolerance factor for the series LaAMnMO{sub 6} (A = Ca, Sr, Ba; M = Sn, Ru) provides a better understanding of the symmetry determination for double perovskites.

  4. Atomic and electronic structure of the ferroelectric BaTiO{sub 3}/Ge(001) interface

    SciTech Connect (OSTI)

    Fredrickson, Kurt D.; Ponath, Patrick; Posadas, Agham B.; Demkov, Alexander A.; McCartney, Martha R.; Smith, David J.; Aoki, Toshihiro

    2014-06-16

    In this study, we demonstrate the epitaxial growth of BaTiO{sub 3} on Ge(001) by molecular beam epitaxy using a thin Zintl template buffer layer. A combination of density functional theory, atomic-resolution electron microscopy and in situ photoemission spectroscopy is used to investigate the electronic properties and atomic structure of the BaTiO{sub 3}/Ge interface. Aberration-corrected scanning transmission electron micrographs reveal that the Ge(001) 2??1 surface reconstruction remains intact during the subsequent BaTiO{sub 3} growth, thereby enabling a choice to be made between several theoretically predicted interface structures. The measured valence band offset of 2.7?eV matches well with the theoretical value of 2.5?eV based on the model structure for an in-plane-polarized interface. The agreement between the calculated and measured band offsets, which are highly sensitive to the detailed atomic arrangement, indicates that the most likely BaTiO{sub 3}/Ge(001) interface structure has been identified.

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

    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.

  6. Charge trapping of Ge-nanocrystals embedded in TaZrO{sub x} dielectric films

    SciTech Connect (OSTI)

    Lehninger, D. Seidel, P.; Geyer, M.; Schneider, F.; Heitmann, J.; Klemm, V.; Rafaja, D.; Borany, J. von

    2015-01-12

    Ge-nanocrystals (NCs) were synthesized in amorphous TaZrO{sub x} by thermal annealing of co-sputtered Ge-TaZrO{sub x} layers. Formation of spherical shaped Ge-NCs with small variation of size, areal density, and depth distribution was confirmed by high-resolution transmission electron microscopy. The charge storage characteristics of the Ge-NCs were investigated by capacitance-voltage and constant-capacity measurements using metal-insulator-semiconductor structures. Samples with Ge-NCs exhibit a maximum memory window of 5 V by sweeping the bias voltage from −7 V to 7 V and back. Below this maximum, the width of the memory window can be controlled by the bias voltage. The fitted slope of the memory window versus bias voltage characteristics is very close to 1 for samples with one layer Ge-NCs. A second layer Ge-NCs does not result in a second flat stair in the memory window characteristics. Constant-capacity measurements indicate charge storage in trapping centers at the interfaces between the Ge-NCs and the surrounding materials (amorphous matrix/tunneling oxide). Charge loss occurs by thermal detrapping and subsequent band-to-band tunneling. Reference samples without Ge-NCs do not show any memory window.

  7. Irradiation performance of U-Pu-Zr metal fuels for liquid-metal-cooled reactors

    SciTech Connect (OSTI)

    Tsai, H.; Cohen, A.B.; Billone, M.C.; Neimark, L.A.

    1994-10-01

    This report discusses a fuel system utilizing metallic U-Pu-Zr alloys which has been developed for advanced liquid metal-cooled reactors (LMRs). Result`s from extensive irradiation testing conducted in EBR-II show a design having the following key features can achieve both high reliability and high burnup capability: a cast nominally U-20wt %Pu-10wt %Zr slug with the diameter sized to yield a fuel smear density of {approx}75% theoretical density, low-swelling tempered martensitic stainless steel cladding, sodium bond filling the initial fuel/cladding gap, and an as-built plenum/fuel volume ratio of {approx}1.5. The robust performance capability of this design stems primarily from the negligible loading on the cladding from either fuel/cladding mechanical interaction or fission-gas pressure during the irradiation. The effects of these individual design parameters, e.g., fuel smear density, zirconium content in fuel, plenum volume, and cladding types, on fuel element performance were investigated in a systematic irradiation experiment in EBR-II. The results show that, at the discharge burnup of {approx}11 at. %, variations on zirconium content or plenum volume in the ranges tested have no substantial effects on performance. Fuel smear density, on the other hand, has pronounced but countervailing effects: increased density results in greater cladding strain, but lesser cladding wastage from fuel/cladding chemical interaction.

  8. 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 3040?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.

  9. 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.

  10. 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 10e m 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 electronsolid 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.

  11. 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 200C 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.

  12. 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.

  13. 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 6.7C/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 200C shows the formation of deep trapping in prepared sample. The high temperature peak shows the less fading and more stability in prepared sample.

  14. 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.

  15. 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

    Tmore » he addition of Molybdenum was used to modify the nanostructure and enhance coercivity of rare-earth-free Zr2Co11-based nanocrystalline permanent magnets. he 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. he coercivity of the samples increases with the increase in Mo content (x≤1.5). he maximum energy product(BH)maxincreases with increasingxfrom 0.5 MGOe forx=0to a maximum value of 4.2 MGOe forx=1.5. he smallest domain size with a relatively short magnetic correlation length of 128 nm and largest root-mean-square phase shiftΦrmsvalue of 0.66° are observed for thex=1.5. he optimal Mo addition promotes magnetic domain structure refinement and thus leads to a significant increase in coercivity and energy product in this sample.« less

  16. The first mixed-halide zirconium cluster compounds: Zr{sub 6}Cl{sub 1.6}I{sub 10.4}Be, Zr{sub 6}Cl{sub 1.3}I{sub 10.7}B, and Zr{sub 6}Cl{sub 11.5}I{sub 1.5}B. Matrix effects and halogen substitution in compact network structures

    SciTech Connect (OSTI)

    Koeckerling, M.; Qi, R.Y.; Corbett, J.D.

    1996-03-13

    Investigations of the effect of halogen size on structure stability have been conducted in well-reduced and heavily interbridged zirconium chloride-iodide cluster systems. The title compounds are obtained in good yields from reactions of Zr, ZrCl{sub 4}, ZrI{sub 4}, and B or Be in sealed Ta tubes for {approximately} 4 weeks at 850 {degrees}C. Single-crystal diffraction at room temperature established these as Zr{sub 6}Cl{sub 1.65(4)}I{sub 10.35(4)}Be and Zr{sub 6}Cl{sub 1.27/(3)}. These are derivatives of the Zr{sub 6}I{sub 12}C and orthorhombic Zr{sub 6}Cl{sub 13}B structures, respectively, the latter containing unusual linear chains of clusters interbridged by Cl{sup i-i} that are in turn interconnected by three-bonded Cl{sup a-a-a} atoms. The random substitution of fractional Cl at specific I sites in the first two, and I for certain Cl in the third, was positionally resolved in all cases. The replacement always occurs at two-bonded X{sup i}, so that single types of halogen are left in sites that interconnected clusters and generate the three-dimensional array. Structural changes seen in both structures are specifically related to relief of X{hor_ellipsis}X crowding in the parent structure (matrix effects). Substitution of Cl for I{sup i} in the Zr{sub 6}I{sub 12}C type greatly reduces intercluster I{hor_ellipsis}I repulsions and allows, among other things, a 0.20 {Angstrom} (5.8*5) reduction in Zr-I{sup 1-i} intercluster bond lengths. Increased Cl{hor_ellipsis}I repulsions caused by I substitution in orthorhombic Zr{sub 6}Cl{sub 11.5}I{sub 1.5}B. Phase widths found are 0{le} x {le} 1.4 for Zr{sub 6}Cl{sub x}I{sub 12-x}Z (Z=B, Be) and 0 {le} x {le} 1.5 for Zr{sub 6}Cl{sub 13-x}I{sub x}B. The limit for iodine substitution in the chlorine-rich rhombohedral Zr{sub 6}Cl{sub 12-x}I{sub x}Be is about x=2.5.

  17. Controlled synthesis and optical properties of BaFBr:Eu{sup 2+} crystals via ethanol/water solutions

    SciTech Connect (OSTI)

    Liang, Qinghua; Graduate University of Chinese Academy of Sciences, Beijing 10039 ; Li, Zhi; Ma, Wangjing; Shi, Yao; Yang, Xinmin

    2012-09-15

    Graphical abstract: A facile and cost-effective approach for the controlled synthesis of BaFBr:Eu{sup 2+} crystals is introduced. The structures and morphologies of the obtained products are affected by the amount of water and ethanol in the solvent mixtures. Highlights: ► Precipitation route for preparing BaFBr nano and micro crystals in water/ethanol solvent mixtures. ► Controlled growth of BaFBr nano crystals by tuning the volume ratio of Ethanol/water. ► Luminescence properties after annealing at 200 °C are investigated. ► Short lifetimes of photoluminescence and photostimulated luminescence in BaFBr:Eu{sup 2+} nano crystals are presented. ► Shortened lifetimes in BaFBr:Eu{sup 2+} nano crystals demonstrate that they are promising materials for use in X-ray imaging systems. -- Abstract: BaFBr:Eu{sup 2+} crystals with different structures were successfully fabricated via a simple precipitation method using ethanol/water mixtures as solvents. The amount of ethanol in the solvent mixtures played a significant role in the formation of final products, enabling the well-controlled growth of the BaFBr crystals. A possible formation mechanism was proposed based on the results of controlled experiments. The phases and morphologies of the resulting samples were systematically investigated by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), selected area electron diffraction (SAED) and elementary analysis. The optical properties of the annealed BaFBr:Eu{sup 2+} nano-cuboids were investigated using photoluminescence (PL), photo-stimulated luminescence spectroscopy (PSL) and kinetic decays. Faster decay behaviors demonstrate that these BaFBr:Eu{sup 2+} phosphors are promising materials for applications in optical storage fields. Furthermore, it is envisaged that this environmentally benign method can be extended to prepare other fluoride halides.

  18. Synthesis, structural and magnetic characterisation of the fully fluorinated compound 6H-BaFeO{sub 2}F

    SciTech Connect (OSTI)

    Clemens, Oliver; Wright, Adrian J.; Berry, Frank J.; Smith, Ronald I.; Slater, Peter R.

    2013-02-15

    The compound 6H-BaFeO{sub 2}F (P6{sub 3}/mmc) was synthesised by the low temperature fluorination of 6H-BaFeO{sub 3-d} using polyvinylidenedifluoride (PVDF) as a fluorination agent. Structural characterisation by XRD and NPD suggests that the local positions of the oxygen and fluorine atoms vary with no evidence for ordering on the anion sites. This compound shows antiferromagnetic ordering at room temperature with antiparallel alignment of the magnetic moments along the c-axis. The use of PVDF also allows the possibility of tuning the fluorine content in materials of composition 6H-BaFeO{sub 3-d}F{sub y} to any value of 0BaFeO{sub 2}F. Highlights: Black-Right-Pointing-Pointer The crystal structure of the hexagonal perovskite phase 6H-BaFeO{sub 2}F. Black-Right-Pointing-Pointer H-BaFeO{sub 2}F and 6H-BaFeO{sub 3-d}F{sub y} were prepared via low temperature fluorination using PVDF. Black-Right-Pointing-Pointer A structural investigation of the compounds BaFeO{sub 2}F is presented in detail. Black-Right-Pointing-Pointer This analysis suggests differences for the local coordination of O{sup 2-} and F{sup -} anions. Black-Right-Pointing-Pointer H-BaFeO{sub 2}F shows antiferromagnetic ordering at 300 K. Black-Right-Pointing-Pointer The magnetic moments align parallel to the a-axis.

  19. Zero added oxygen for high quality sputtered ITO. A data science investigation of reduced Sn-content and added Zr

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

    Peshek, Timothy J.; Burst, James M.; Coutts, Timothy J.; Gessert, Timothy A.

    2016-01-19

    Here, we demonstrate mobilities of >45 cm2/V s for sputtered tin-doped indium oxide (ITO) films at zero added oxygen. All films were deposited with 5 wt. % SnO2, instead of the more conventional 8–10 wt. %, and had varying ZrO2 content from 0 to 3 wt. %, with a subsequent reduction in In2O3 content. Moreover, these films were deposited by radio-frequency magnetron sputtering from nominally stoichiometric targets with varying oxygen partial pressure in the sputter ambient. Anomalous behavior was discovered for films with no Zr-added, where a bimodality of high and low mobilities was discovered for nominally similar growth conditions.more » However, all films showed the lowest resistivity and highest mobilities when the oxygen partial pressure in the sputter ambient was zero. This result is contrasted with several other reports of ITO transport performance having a maximum for small but nonzero oxygen partial pressure. Our result is attributed to the reduced concentration of SnO2. The addition of ZrO2 yielded the highest mobilities at >55 cm2/V s and the films showed a modest increase in optical transmission with increasing Zr-content.« less

  20. Synthesis, structural and magnetic characterisation of the fluorinated compound 15R-BaFeO{sub 2}F

    SciTech Connect (OSTI)

    Clemens, Oliver; Berry, Frank J.; Bauer, Jessica; Wright, Adrian J.; Knight, Kevin S.; Slater, Peter R.

    2013-07-15

    The compounds 15R-BaFeO{sub 2}F and 15R-BaFeO{sub 2.27}F{sub 0.5} have been synthesised by the low temperature fluorination of 15R-BaFeO{sub 3−d}F{sub 0.2} using polyvinylidenedifluoride (PVDF) as a fluorination agent. The materials have been structurally characterised by Rietveld analysis of the X-ray- and HRPD-powder neutron diffraction data. A detailed analysis of bond valence sums suggests that the oxide and fluoride ions order on the different anion sites. A reinvestigation of our recently published structure (Clemens et al., 2013) [34] of 6H-BaFeO{sub 2}F is also reported and incorporation of fluoride in h-type layers is also confirmed in this compound. The magnetic moments for 15R-BaFeO{sub 2}F and 15R-BaFeO{sub 2.25}F{sub 0.5} align in the a/b-plane with antiferromagnetic alignment of the moments between adjacent layers, and are flipped by 90° as compared to the precursor compound. 15R-BaFeO{sub 2}F exhibits very robust antiferromagnetism with a Néel temperature between 300 and 400 °C. - Graphical abstract: The crystal and magnetic structure of the perovskite phase 15R-BaFeO{sub 2}F. - Highlights: • 15R-BaFeO{sub 2}F and 15R-BaFeO{sub 2.27}F{sub 0.5}were prepared via low temperature fluorination using PVDF. • A structural investigation of the compounds BaFeO{sub 2}F is presented in detail. • This analysis suggests ordering of O{sup 2−} and F{sup −} anions between different layers. • 15R-BaFeO{sub 2}F shows antiferromagnetic ordering at 300 K with T{sub N} ∼300–400 °C. • The magnetic moments align in the a/b-plane.

  1. 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.

  2. Effects of Pt and Zr on the oxidation behavior of FeTbCo magneto-optic films: X-ray photoelectron spectroscopy

    SciTech Connect (OSTI)

    Majumdar, D.; Hatwar, T. K.

    1989-07-01

    We report the effects of Pt and Zr on the oxidation behavior of FeTbCo magneto-optic films. The addition of 10 at. % Pt or Zr increased environmental stability without significantly affecting the magneto-optic properties. X-ray photoelectron spectroscopy was used to study /ital in/ /ital situ/ oxidation of clean FeTbCoPt and FeTbCoZr films under 5/times/10/sup /minus/7/ Torr of oxygen at room temperature. Pt and Zr played different roles in increasing the oxidation resistance of the alloy. In the FeTbCoPt alloy, Pt reduced the oxygen uptake and retarded the oxidation kinetics of Fe. No oxidation of Pt was observed. In the FeTbCoZr alloy, Zr oxidized readily and segregated to the surface to form a protective layer. The Tb/Fe ratio at the surface increased with oxygen exposure in both alloys but at a faster rate in the FeTbCoPt alloy than in the FeTbCoZr alloy.

  3. Growth kinetics and microstructural evolution during hot isostatic pressing of U-10 wt.% Mo monolithic fuel plate in AA6061 cladding with Zr diffusion barrier

    SciTech Connect (OSTI)

    Y. Park; J. Yoo; K. Huang; D. D. Keiser, Jr.; J. F. Jue; B. Rabin; G. Moore; Y. H. Sohn

    2014-04-01

    Phase constituents and microstructure changes in RERTR fuel plate assemblies as functions of temperature and duration of hot-isostatic pressing (HIP) during fabrication were examined. The HIP process was carried out as functions of temperature (520, 540, 560 and 580 °C for 90 min) and time (45–345 min at 560 °C) to bond 6061 Al-alloy to the Zr diffusion barrier that had been co-rolled with U-10 wt.% Mo (U10Mo) fuel monolith prior to the HIP process. Scanning and transmission electron microscopies were employed to examine the phase constituents, microstructure and layer thickness of interaction products from interdiffusion. At the interface between the U10Mo and Zr, following the co-rolling, the UZr2 phase was observed to develop adjacent to Zr, and the a-U phase was found between the UZr2 and U10Mo, while the Mo2Zr was found as precipitates mostly within the a-U phase. The phase constituents and thickness of the interaction layer at the U10Mo-Zr interface remained unchanged regardless of HIP processing variation. Observable growth due to HIP was only observed for the (Al,Si)3Zr phase found at the Zr/AA6061 interface, however, with a large activation energy of 457 ± 28 kJ/mole. Thus, HIP can be carried to improve the adhesion quality of fuel plate without concern for the excessive growth of the interaction layer, particularly at the U10Mo-Zr interface with the a-U, Mo2Zr, and UZr2 phases.

  4. A high surface area Zr(IV)-based metal–organic framework showing stepwise gas adsorption and selective dye uptake

    SciTech Connect (OSTI)

    Lv, Xiu-Liang; Tong, Minman; Huang, Hongliang; Wang, Bin; Gan, Lei; Yang, Qingyuan; Zhong, Chongli; Li, Jian-Rong

    2015-03-15

    Exploitation of new metal–organic framework (MOF) materials with high surface areas has been attracting great attention in related research communities due to their broad potential applications. In this work, a new Zr(IV)-based MOF, [Zr{sub 6}O{sub 4}(OH){sub 4}(eddb){sub 6}] (BUT-30, H{sub 2}eddb=4,4′-(ethyne-1,2-diyl)dibenzoic acid) has been solvothermally synthesized, characterized, and explored for gases and dyes adsorptions. Single-crystal X-ray diffraction analysis demonstrates a three-dimensional cubic framework structure of this MOF, in which each Zr{sub 6}O{sub 4}(OH){sub 4} building unit is linked by 12 linear eddb ligands. BUT-30 has been found stable up to 400 °C and has a Brunauer–Emmett–Teller (BET) surface area as high as 3940.6 m{sup 2} g{sup −1} (based on the N{sub 2} adsorption at 77 K) and total pore volume of 1.55 cm{sup 3} g{sup −1}. It is more interesting that this MOF exhibits stepwise adsorption behaviors for Ar, N{sub 2}, and CO{sub 2} at low temperatures, and selective uptakes towards different ionic dyes. - Graphical abstract: A new Zr(IV)-based MOF with high surface area has been synthesized and structurally characterized, which shows stepwise gas adsorption at low temperature and selective dye uptake from solution. - Highlights: • A new Zr-based MOF was synthesized and structurally characterized. • This MOF shows a higher surface area compared with its analogous UiO-67 and 68. • This MOF shows a rare stepwise adsorption towards light gases at low temperature. • This MOF performs selective uptakes towards cationic dyes over anionic ones. • Using triple-bond spacer is confirmed feasible in enhancing MOF surface areas.

  5. Crystal structure and physical properties of quaternary clathrates Ba{sub 8}Zn{sub x}Ge{sub 46-x-y}Si{sub y}, Ba{sub 8}(Zn,Cu){sub x}Ge{sub 46-x} and Ba{sub 8}(Zn,Pd){sub x}Ge{sub 46-x}

    SciTech Connect (OSTI)

    Nasir, Navida; Grytsiv, Andriy; Melnychenko-Koblyuk, Nataliya; Rogl, Peter; Bednar, Ingeborg; Bauer, Ernst

    2010-10-15

    Three series of vacancy-free quaternary clathrates of type I, Ba{sub 8}Zn{sub x}Ge{sub 46-x-y}Si{sub y}, Ba{sub 8}(Zn,Cu){sub x}Ge{sub 46-x}, and Ba{sub 8}(Zn,Pd){sub x}Ge{sub 46-x}, have been prepared by reactions of elemental ingots in vacuum sealed quartz at 800 {sup o}C. In all cases cubic primitive symmetry (space group Pm3n, a{approx}1.1 nm) was confirmed for the clathrate phase by X-ray powder diffraction and X-ray single crystal analyses. The lattice parameters show a linear increase with increase in Ge for Ba{sub 8}Zn{sub x}Ge{sub 46-x-y}Si{sub y}. M atoms (Zn, Pd, Cu) preferably occupy the 6d site in random mixtures. No defects were observed for the 6d site. Site preference of Ge and Si in Ba{sub 8}Zn{sub x}Ge{sub 46-x-y}Si{sub y} has been elucidated from X-ray refinement: Ge atoms linearly substitute Si in the 24k site whilst a significant deviation from linearity is observed for occupation of the 16i site. A connectivity scheme for the phase equilibria in the 'Ba{sub 8}Ge{sub 46}' corner at 800 {sup o}C has been derived and a three-dimensional isothermal section at 800 {sup o}C is presented for the Ba-Pd-Zn-Ge system. Studies of transport properties carried out for Ba{sub 8{l_brace}}Cu,Pd,Zn{r_brace}{sub x}Ge{sub 46-x} and Ba{sub 8}Zn{sub x}Si{sub y}Ge{sub 46-x-y} evidenced predominantly electrons as charge carriers and the closeness of the systems to a metal-to-insulator transition, fine-tuned by substitution and mechanical processing of starting material Ba{sub 8}Ge{sub 43}. A promising figure of merit, ZT {approx}0.45 at 750 K, has been derived for Ba{sub 8}Zn{sub 7.4}Ge{sub 19.8}Si{sub 18.8}, where pricey germanium is exchanged by reasonably cheap silicon. - Graphical abstract: Quaternary phase diagram of Ba-Pd-Zn-Ge system at 800 {sup o}C.

  6. 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.; Subramanian, N. Sankara; Loganathan, S.

    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.

  7. 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.

  8. Compliant ferroelastic domains in epitaxial Pb(Zr,Ti)O{sub 3} thin films

    SciTech Connect (OSTI)

    Feigl, L.; McGilly, L. J.; Sandu, C. S.; Setter, N.

    2014-04-28

    Ordered patterns of highly compliant ferroelastic domains have been created by use of tensile strained epitaxial Pb(Zr,Ti)O{sub 3} thin films, of very low defect density, grown on DyScO{sub 3} substrates. The effect of 180° switching on well-ordered a/c 90° domain patterns is investigated by a combination of transmission electron microscopy, piezoelectric force microscopy, and X-ray diffraction. It is shown that ferroelastic a-domains, having an in-plane polarization, can be created and completely removed on a local level by an out-of-plane electric field. The modifications of the ferroelastic domain pattern can be controlled by varying the parameters used during switching with a piezoresponse force microscope to produce the desired arrangement.

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

    SciTech Connect (OSTI)

    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 up in the frequency-dependent optical conductivity, indicating the presence of a Van Hove singularity in the joint density of state.

  10. Optical and mechanical properties of nanocrystalline ZrC thin films grown by pulsed laser deposition.

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

    Craciun, D.; Socol, G.; Lambers, E.; McCumiskey, E. J.; Taylor, C. R.; Martin, C.; Argibay, Nicolas; Craciun, V.; Tanner, D. B.

    2015-01-17

    Thin ZrC films (<500 nm) were grown on (100) Si substrates at a substrate temperature of 500 °C by the pulsed laser deposition (PLD) technique using a KrF excimer laser under different CH4 pressures. Glancing incidence X-ray diffraction showed that films were nanocrystalline, while X-ray reflectivity studies found out films were very dense and exhibited a smooth surface morphology. Optical spectroscopy data shows that the films have high reflectivity (>90%) in the infrared region, characteristic of metallic behavior. Nanoindentation results indicated that films deposited under lower CH4 pressures exhibited slightly higher nanohardness and Young modulus values than films deposited undermore » higher pressures. As a result, tribological characterization revealed that these films exhibited relatively high wear resistance and steady-state friction coefficients on the order of μ = 0.4.« less

  11. Optical and mechanical properties of nanocrystalline ZrC thin films grown by pulsed laser deposition.

    SciTech Connect (OSTI)

    Craciun, D.; Socol, G.; Lambers, E.; McCumiskey, E. J.; Taylor, C. R.; Martin, C.; Argibay, Nicolas; Craciun, V.; Tanner, D. B.

    2015-01-17

    Thin ZrC films (<500 nm) were grown on (100) Si substrates at a substrate temperature of 500 °C by the pulsed laser deposition (PLD) technique using a KrF excimer laser under different CH4 pressures. Glancing incidence X-ray diffraction showed that films were nanocrystalline, while X-ray reflectivity studies found out films were very dense and exhibited a smooth surface morphology. Optical spectroscopy data shows that the films have high reflectivity (>90%) in the infrared region, characteristic of metallic behavior. Nanoindentation results indicated that films deposited under lower CH4 pressures exhibited slightly higher nanohardness and Young modulus values than films deposited under higher pressures. As a result, tribological characterization revealed that these films exhibited relatively high wear resistance and steady-state friction coefficients on the order of μ = 0.4.

  12. 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.

  13. 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

  14. 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.

  15. Optical properties of Pr-doped BaY{sub 2}F{sub 8}

    SciTech Connect (OSTI)

    Andrade, Adriano B. Mello, Ana C. S. de; Valerio, Mrio E. G.; Rezende, Marcos V. dos S.; Baldochi, Sonia L.

    2014-08-07

    Crystalline samples of Pr-doped BaY{sub 2}F{sub 8} (BaYF) were prepared by zone melting technique. The pure phase obtained was identified by X-ray diffraction measurement. Optical absorption result was evaluated and it showed that the formation of the absorption bands can be connected to color centers generated by radiation in the matrix. Radioluminescence emission measurements after excitation by X-ray showed that the material exhibited components responsible for long lasting phosphorescence. Short decay times were also evaluated, the measurements showed a fast component around 70?ns associated to the 4f{sup 1}5d{sup 1} ? 4f{sup 2} transition of the Pr{sup 3+} ion. The Thermoluminescence (TL) results indicate the presence of two trapping centers.

  16. Single crystal growth and characterization of the large-unit-cell compound Cu13Ba

    SciTech Connect (OSTI)

    Jesche, Anton; Budko, Serguei L.; Canfield, Paul C.

    2013-10-31

    Single crystals of Cu13Ba were successfully grown out of BaCu self flux. Temperature dependent magnetization, M (T ), electrical resistivity, ?(T)?(T), and specific heat, Cp(T)Cp(T), data are reported. Isothermal magnetization measurements, M(H)M(H), show clear de Haas-van Alphen oscillations at T = 2 K for applied fields as low as View the MathML source?0H=1T. An anomalous behavior of the magnetic susceptibility is observed up to T ? 50 K reflecting the effect of de Haas-van Alphen oscillations at fairly high temperatures. The field- and temperature-dependencies of the magnetization indicate the presence of diluted magnetic impurities with a concentration of the order of 0.01 at.%. Accordingly, the minimum and lower temperature rise observed in the electrical resistivity at and below T = 15 K is attributed to the Kondo-impurity effect.

  17. Melt-processing of Y-Ba-Cu-O superconductors for improved levitation

    SciTech Connect (OSTI)

    Balachandran, U.; Zhong, W.; Emerson, J.E.; McDaniel, R.L.

    1994-04-01

    Melt processed bulk YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} (YBCO) superconductors are of considerable interest in the application of low-friction, superconducting permanent magnet bearings and flywheel-energy-storage devices. The mechanisms of enhanced flux pinning in the melt processed samples has been the subject of many investigations. Fine precipitates of Y{sub 2}BaCuO{sub 5} (211) are considered potential flux-pinning sites by many investigators. Several groups have reported the refinement of 211 precipitates through Pt additions. In this paper, the authors describe the melt processing of YBCO with additives such as 211, Pt, and Ag. Large single domain regions are obtained using small SmBa2Cu3O{sub 7{minus}{delta}} (Sm-123) single crystal seeds. The microstructure and levitation forces are measured and reported here.

  18. Infrared-optical spectroscopy of transparent conducting perovskite (La,Ba)SnO{sub 3} thin films

    SciTech Connect (OSTI)

    Seo, Dongmin; Yu, Kwangnam; Jun Chang, Young; Choi, E. J.; Sohn, Egon; Hoon Kim, Kee

    2014-01-13

    We have performed optical transmission, reflection, spectroscopic ellipsometry, and Hall effect measurements on the electron-doped La{sub x}Ba{sub 1x}SnO{sub 3} (x?=?0.04) transparent thin films. From the infrared Drude response and plasma frequency analysis we determine the effective mass of the conducting electron m*?=?0.35m{sub 0}. In the visible-UV region the optical band gap shifts to high energy in (La,Ba)SnO{sub 3} by 0.18?eV compared with undoped BaSnO{sub 3} which, in the context of the Burstein-Moss analysis, is consistent with the infrared-m*. m* of BaSnO{sub 3} is compared with other existing transparent conducting oxides (TCO), and implication on search for high-mobility TCO compounds is discussed.

  19. K and Mn co-doped BaCd{sub 2}As{sub 2}: A hexagonal structured...

    Office of Scientific and Technical Information (OSTI)

    K and Mn co-doped BaCdsub 2Assub 2: A hexagonal structured bulk diluted magnetic semiconductor with large magnetoresistance Citation Details In-Document Search Title: K and Mn ...

  20. Solution-Derived Bi(ZnTi)O3 - BaTiO3 Thin Films with Bulk-like...

    Office of Scientific and Technical Information (OSTI)

    Title: Solution-Derived Bi(ZnTi)O3 - BaTiO3 Thin Films with Bulk-like Permittivity. Abstract not provided. Authors: Meyer, Kelsey Elizabeth ; Kotula, Paul Gabriel ; Brennecka, ...

  1. Fermi surfaces and phase stability of Ba(Fe1-xMx)2As2 (M = Co...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Fermi surfaces and phase stability of Ba(Fe1-xMx)2As2 (M Co,Ni,Cu,Zn) ... (EFRC); Center for Defect Physics in Structural Materials (CDP) Sponsoring Org: USDOE ...

  2. Recent Results on D0 - Anti-D0 Mixing from BaBar and Belle (Conference...

    Office of Scientific and Technical Information (OSTI)

    Title: Recent Results on D0 - Anti-D0 Mixing from BaBar and Belle Authors: Neri, Nicola ; Pisa U. INFN, Pisa Publication Date: 2013-06-04 OSTI Identifier: 1082815 Report ...

  3. Data:3dfe9516-886e-413a-baed-ae8390939e0b | Open Energy Information

    Open Energy Info (EERE)

    dfe9516-886e-413a-baed-ae8390939e0b No revision has been approved for this page. It is currently under review by our subject matter experts. Jump to: navigation, search Loading......

  4. Phase relations and hardness trends of ZrO[subscript 2] phases at high pressure

    SciTech Connect (OSTI)

    Al-Khatatbeh, Yahya; Lee, Kanani K.M.; Kiefer, Boris

    2010-07-23

    We use high-resolution synchrotron x-ray powder diffraction and density-functional theory (DFT) to investigate the phase stability, equations of state (EOSs), and mechanical hardness of zirconia (ZrO{sub 2}) up to {approx}54 and 160 GPa, respectively. For the equilibrium phase at ambient conditions (MI), we provide an experimental EOS that is comparable to results obtained from room-pressure Brillouin scattering experiments and bulk modulus-volume systematics but different from previous high-pressure experiments. The experimental second-order Birch-Murnaghan EOS parameters of MI-ZrO{sub 2} are: ambient-pressure volume (V{sub 0}) of 35.15({+-}0.03) {angstrom}{sup 3}/f.u. with an ambient-pressure bulk modulus K{sub 0} of 210({+-}28) GPa. For the high-pressure OI phase, we find that the K{sub 0} = 290({+-}11) GPa, which is 19%-32% higher than previously determined, and V{sub 0} = 33.65({+-}0.07) {angstrom}{sup 3}/f.u. The small volume decrease of 3.4% across the MI {yields} OI transition at {approx}10 GPa is associated with a 38% increase in the bulk modulus consistent with our DFT calculations that predict a {approx}36% and 39% increase in K{sub 0} for the generalized gradient and local density approximations, respectively. In contrast to the EOS of MI and OI, we find that our experimental EOS for the high-pressure OII phase is in good agreement with previous measurements. The large volume decrease across the OI {yields} OII phase transition as obtained from both our experiments and calculations is {approx}10%. Our estimates, using scaling relations, indicate that this phase, while dense and quenchable, may have a comparatively low mechanical hardness of {approx} 10 GPa.

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

    DOE Patents [OSTI]

    White, Jack C.; Oden, Laurance L.

    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.

  6. 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.

  7. A Measurement of the Exclusive Branching Fraction for B → π K at BaBar

    SciTech Connect (OSTI)

    Aspinwall, Marie Louise

    2002-02-01

    This thesis presents an exclusive measurement of the branching fraction B for the rare charmless hadronic B decays to πK final states. A sample of 22.57±0.36 million BB pairs was collected with the BaBar detector at the Stanford Linear Accelerator Center's PEP-II B Factory, during the Run 1 data taking period (1999-2000).

  8. Dielectric investigations in nanostructured tetragonal BaTiO{sub 3} ceramics

    SciTech Connect (OSTI)

    Silveira, L.G.D.; Alves, M.F.S.; Ctica, L.F.; Gotardo, R.A.M.; Nascimento, W.J.; Garcia, D.; Eiras, J.A.; Santos, I.A.

    2013-05-15

    Highlights: ? Nanostructured BaTiO{sub 3} ceramics processed by an innovative protocol. ? Dielectric relaxations related to strains and vacancies. ? Dielectric and ferroelectric properties enhanced by strain. - Abstract: In this paper, structural and dielectric properties of BaTiO{sub 3} ceramics obtained under extreme conditions were investigated. The temperature dependent dielectric investigations revealed that the phase transition temperatures of the BaTiO{sub 3} ceramics were raised as a function of residual strains associated to the nanostructuration, while structural characterizations showed a tetragonal arrangement at room temperature. From the frequency dependence analyses of the imaginary parts of dielectric permittivity, impedance and modulus function, three relaxation processes were identified. Two of them exhibit activation energies of 0.45 and 0.63 eV, and were attributed to single and double-ionization of oxygen vacancies. The whole set of results also indicated that the electrons resulting from the ionization of oxygen vacancies are trapped and do not contribute to the electrical conductivity, while the physical properties of the analyzed samples were enhanced by retaining a strained microstructure.

  9. Hydrodynamic Modeling Analysis for Leque Island and zis a ba Restoration Feasibility Study

    SciTech Connect (OSTI)

    Whiting, Jonathan M.; Khangaonkar, Tarang

    2015-01-31

    Ducks Unlimited, Inc. in collaboration with Washington State Department of Fish and Wildlife (WDFW), and Stillaguamish Tribe of Indians have proposed the restoration of Leque Island and zis a ba (formerly Matterand) sites near the mouth of Old Stillaguamish River Channel in Port Susan Bay, Washington. The Leque Island site, which is owned by WDFW, consists of nearly 253 acres of land south of Highway 532 that is currently behind a perimeter dike. The 90-acres zis a ba site, also shielded by dikes along the shoreline, is located just upstream of Leque Island and is owned by Stillaguamish Tribes. The proposed actions consider the removal or modification of perimeter dikes at both locations to allow estuarine functions to be restored. The overall objective of the proposed projects is to remove the dike barriers to 1) provide connectivity and access between the tidal river channel and the restoration site for use by juvenile migrating salmon and 2) create a self-sustaining tidal marsh habitat. Ducks Unlimited engaged Pacific Northwest National Laboratory (PNNL) to develop a three-dimensional hydrodynamic model of the Port Susan Bay, Skagit Bay, and the interconnecting Leque Island region for use in support of the feasibility assessment for the Leque Island and zis a ba restoration projects. The objective of this modeling-based feasibility assessment is to evaluate the performance of proposed restoration actions in terms of achieving habitat goals while assessing the potential hydraulic and sediment transport impacts to the site and surrounding parcels of land.

  10. Growth and self-assembly of BaTiO{sub 3} nanocubes for resistive switching memory cells

    SciTech Connect (OSTI)

    Chu, Dewei, E-mail: D.Chu@unsw.edu.au [School of Materials Science and Engineering, University of New South Wales, Sydney, 2052 NSW (Australia); Lin, Xi; Younis, Adnan [School of Materials Science and Engineering, University of New South Wales, Sydney, 2052 NSW (Australia); Li, Chang Ming [Chongqing Key Lab for Advanced Materials and Clean Energies of Techonologies Dean, Institute for Clean Energy and Advanced Materials, Southwest University, Chongqing (China); Dang, Feng [Research Center for Materials Back Casting Technology (MBT Center), Nagoya University, Nagoya 464-8603 (Japan); Li, Sean [School of Materials Science and Engineering, University of New South Wales, Sydney, 2052 NSW (Australia)

    2014-06-01

    In this work, the self-assembled BaTiO{sub 3} nanocubes based resistive switching memory capacitors are fabricated with hydrothermal and drop-coating approaches. The device exhibits excellent bipolar resistance switching characteristics with ON/OFF ratio of 5870, better reliability and stability over various polycrystalline BaTiO{sub 3} nanostructures. It is believed that the inter cube junctions is responsible for such a switching behaviour and it can be described by the filament model. The effect of film thickness on switching ratio (ON/OFF) was also investigated in details. - Graphical abstract: This work describes a novel resistive switching memory cell based on self-assembled BaTiO{sub 3} nanocubes. - Highlights: BaTiO{sub 3} nanocubes were prepared by one step facile hydrothermal method. Self-assembled BaTiO{sub 3} nanocubes thin films were obtained by drop-coating approach. The BaTiO{sub 3} nanocubes show excellent resistive switching properties for memory applications.

  11. /sup 234/U//sup 230/Th ratio as an indicator of redox state, and U, Th and Ra behavior in briney aquifers

    SciTech Connect (OSTI)

    Laul, J.C.; Smith, M.R.; Hubbard, N.

    1985-06-01

    The /sup 234/U//sup 230/Th ratio serves as an in-situ indicator of the redox state in groundwater aquifers. The higher this ratio, the more U there is in the +6 state and thus a lesser reducing environment. Radium is retarded in the shallow aquifer and its sorption is dependent on the CaSO/sub 4/ content and redox state. Relative to Ra, U and Th are highly sorbed. The total retardation factor for Th is approx.1400 and mean sorption time for /sup 228/Th is approx.10 days in the shallow zone. The desorption rate of Ra is significantly slower in the shallow than in the deep aquifer. There is no effect of colloids in brines. 6 refs., 5 figs., 2 tabs.

  12. /sup 234/U//sup 230/Th ratio as an indicator of redox state, and U/sub 2/, Th, and Ra behavior in Briney aquifers

    SciTech Connect (OSTI)

    Laul, J.C.; Smith, M.R.; Hubbard, N.

    1986-01-01

    The /sup 234/U//sup 230/Th ratio serves as an in-situ indicator of the redox state in groundwater aquifers. The higher this ratio, the more U there is in the +6 valance state and thus a less reducing environment. Radium sorption is retarded in the shallow aquifer and is dependent on the CaSO/sub 4/ content and the redox state. Relative to Ra, U and Th are highly sorbed. The total retardation factor for Th is approx. 1400 and mean sorption time for /sup 228/Th is approx. 10 days in the shallow zone. The desorption rate of Ra is significantly slower in the shallow than in the deep aquifer. There is no effect of colloids in brines.

  13. Action for a Better Community, Inc. … Weatherization Assistance Program Funds Provided by the American Recovery and Reinvestment Act of 2009, OAS-RA-11-21

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

    Examination Report Action for a Better Community, Inc. - Weatherization Assistance Program Funds Provided by the American Recovery and Reinvestment Act of 2009 OAS-RA-11-21 September 2011 Department of Energy Washington, DC 20585 September 30, 2011 MEMORANDUM FOR THE ACTING ASSISTANT SECRETARY FOR ENERGY EFFICIENCY AND RENEWABLE ENERGY FROM: Rickey R. Hass Deputy Inspector General for Audits and Inspections Office of Inspector General SUBJECT: INFORMATION: Examination Report on "Action for

  14. People's Equal Action and Community Effort, Inc. Š Weatherization Assistance Program Funds Provided by the American Recovery and Reinvestment Act of 2009, OAS-RA-11-20

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

    People's Equal Action and Community Effort, Inc. - Weatherization Assistance Program Funds Provided by the American Recovery and Reinvestment Act of 2009 OAS-RA-11-20 September 2011 Department of Energy Washington, DC 20585 September 30, 2011 MEMORANDUM FOR THE ACTING ASSISTANT SECRETARY FOR ENERGY EFFICIENCY AND RENEWABLE ENERGY FROM: Rickey R. Hass Deputy Inspector General for Audits and Inspections Office of Inspector General SUBJECT: INFORMATION: Examination Report on "People's Equal

  15. The 12 GeV CEBAF Upgrade Project at Thomas Jefferson National Accelerator Facility, OAS-RA-L-11-13

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

    12 GeV CEBAF Upgrade Project at Thomas Jefferson National Accelerator Facility OAS-RA-L-11-13 September 2011 Department of Energy Washington, DC 20585 September 30, 2011 MEMORANDUM FOR THE DEPUTY DIRECTOR FOR SCIENCE PROGRAMS, OFFICE OF SCIENCE DIRECTOR, OFFICE OF RISK MANAGEMENT AND FINANCIAL POLICY, OFFICE OF THE CHIEF FINANCIAL OFFICER FROM: David Sedillo, Director NNSA & Science Audits Division Office of Inspector General SUBJECT: INFORMATION: Audit Report on "The 12 GeV CEBAF

  16. The Department of Energy's Clean Cities Alternative Fuel Vehicle Grant Program Funded under the American Recovery and Reinvestment Act, OAS-RA-12-12

    Office of Environmental Management (EM)

    Audit Report The Advanced Research Projects Agency - Energy OAS-RA-11-11 August 2011 Department of Energy Washington, DC 20585 August 22, 2011 MEMORANDUM FOR THE DIRECTOR, ADVANCED RESEARCH PROJECTS AGENCY - ENERGY FROM: George W. Collard Assistant Inspector General for Audits Office of Inspector General SUBJECT: INFORMATION: Audit Report on "The Advanced Research Projects Agency - Energy" BACKGROUND The Advanced Research Projects Agency - Energy (ARPA-E), an agency within the

  17. 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 Environmental Management (EM)

    Energy Efficiency and Conservation Block Grant Program Funded under the American Recovery and Reinvestment Act for the City of Philadelphia OAS-RA-12-09 April 2012 Department of Energy Washington, DC 20585 April 23, 2012 MEMORANDUM FOR THE ASSISTANT SECRETARY FOR ENERGY EFFICIENCY AND RENEWABLE ENERGY FROM: George W. Collard Assistant Inspector General for Audits Office of Inspector General SUBJECT: INFORMATION: Audit Report on "The Department of Energy's Energy Efficiency and Conservation

  18. 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 Environmental Management (EM)

    Missouri OAS-RA-11-12 August 2011 Department of Energy Washington, DC 20585 August 22, 2011 MEMORANDUM FOR THE ACTING ASSISTANT SECRETARY FOR ENERGY EFFICIENCY AND RENEWABLE ENERGY FROM: George W. Collard Assistant Inspector General for Audits Office of Inspector General SUBJECT: INFORMATION: Audit Report on "The Department of Energy's Weatherization Assistance Program under the American Recovery and Reinvestment Act in the State of Missouri" BACKGROUND The Department of Energy's

  19. The Department of Energy's Weatherization Assistance Program under the American Recovery and Reinvestment Act in the State of Ohio, OAS-RA-12-13

    Office of Environmental Management (EM)

    Weatherization Assistance Program under the American Recovery and Reinvestment Act in the State of Ohio OAS-RA-12-13 June 2012 Department of Energy Washington, DC 20585 June 25, 2012 MEMORANDUM FOR THE ASSISTANT SECRETARY, ENERGY EFFICIENCY AND RENEWABLE ENERGY FROM: Rickey R. Hass Deputy Inspector General for Audit Services Office of Inspector General SUBJECT: INFORMATION: Audit Report on "The Department of Energy's Weatherization Assistance Program under the American Recovery and

  20. KCP R.A'S

    National Nuclear Security Administration (NNSA)

  1. Microstructural characterization of a thin film ZrN diffusion barrier in an As-fabricated U7Mo/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 U7 wt.% Mo (U7Mo) 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 U7Mo 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 U7Mo 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 U7Mo/ZrN interface, and no interaction zone was observed at the ZrN/Al interface. The bonding between the U7Mo 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.

  2. The new barium zinc mercurides Ba{sub 3}ZnHg{sub 10} and BaZn{sub 0.6}Hg{sub 3.4} - Synthesis, crystal and electronic structure

    SciTech Connect (OSTI)

    Schwarz, Michael; Wendorff, Marco; Roehr, Caroline

    2012-12-15

    The title compounds Ba{sub 3}ZnHg{sub 10} and BaZn{sub 0.6}Hg{sub 3.4} were synthesized from stoichiometric ratios of the elements in Ta crucibles. Their crystal structures, which both represent new structure types, have been determined using single crystal X-ray data. The structure of Ba{sub 3}ZnHg{sub 10} (orthorhombic, oP28, space group Pmmn, a=701.2(3), b=1706.9(8), c=627.3(3)pm, Z=2, R1=0.0657) contains folded 4{sup 4} Hg nets, where the meshes form the bases of flat rectangular pyramids resembling the structure of BaAl{sub 4}. The flat pyramids are connected via Hg-Zn/Hg bonds, leaving large channels at the folds, in which Ba(1) and Hg(2) atoms alternate. Whereas the remaining Hg/Zn atoms form a covalent 3D network of three- to five-bonded atoms with short M-M distances (273-301 pm; CN 9-11), the Hg(2) atoms in the channels adopt a comparatively large coordination number of 12 and increased distances (317-348 pm) to their Zn/Hg neighbours. In the structure of BaZn{sub 0.6}Hg{sub 3.4} (cubic, cI320, space group I4{sup Macron }3d, a=2025.50(7) pm, Z=64, R1=0.0440), with a chemical composition not much different from that of Ba{sub 3}ZnHg{sub 10}, the Zn/Hg atoms of the mixed positions M(1/2) are arranged in an slightly distorted primitive cubic lattice with a 4 Multiplication-Sign 4 Multiplication-Sign 4 subcell relation to the unit cell. The 24 of the originating 64 cubes contain planar cis tetramers Hg(5,6){sub 4} with Hg in a nearly trigonal planar or tetrahedral coordination. In another 24 of the small cubes, two opposing faces are decorated by Hg(3,4){sub 2} dumbbells, two by Ba(2) atoms respectively. The third type of small cubes are centered by Ba(1) atoms only. The complex 3D polyanionic Hg/Zn network thus formed is compared with the Hg partial structure in Rb{sub 3}Hg{sub 20} applying a group-subgroup relation. Despite their different overall structures, the connectivity of the negatively charged Hg atoms, the rather metallic Zn bonding characteristic

  3. CaO-MgO-Al2O3-SiO2 (CMAS) corrosion of Gd2Zr2O7 and Sm2Zr2O7

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

    Wang, Honglong; Bakal, Ahmet; Zhang, Xingxing; Tarwater, Emily; Sheng, Zhizhi; Fergus, Jeffrey W.

    2016-08-08

    Ceramic thermal barrier coatings are applied to superalloys used in gas turbine engineering to increase the operating temperature and the energy conversion efficiency. However, dust consisting of CaO-MgO-Al2O3-SiO2 (CMAS) from the air can be injected into the engines and corrode the thermal barrier coatings. Lanthanide zirconates are promising materials in thermal barrier coatings due to their low thermal conductivities, good phase stability and good corrosion resistance. However, the corrosion resistance mechanism of CMAS on lanthanide zirconates is still not clearly understood. In this work, the corrosion mechanism of Gd2Zr2O7 and Sm2Zr2O7 in CMAS is studied. Here, the results show thatmore » the CMAS can easily react with lanthanide zirconate thermal barrier coatings to form a dense layer, which can resist further corrosion« less

  4. Ba-filled Ni–Sb–Sn based skutterudites with anomalously high lattice thermal conductivity

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

    Paschinger, W.; Rogl, Gerda; Grytsiv, A.; Michor, H.; Heinrich, P. R.; Mueller, H.; Puchegger, S.; Klobes, B.; Hermann, Raphael P.; Reinecker, M.; et al

    2016-06-21

    Here, in this study, novel filled skutterudites BayNi4Sb12-xSnx (ymax = 0.93) have been prepared by arc melting followed by annealing at 250, 350 and 450°C up to 30 days in vacuum-sealed quartz vials. Extension of the homogeneity region, solidus temperatures and structural investigations were performed for the skutterudite phase in the ternary Ni–Sn–Sb and in the quaternary Ba–Ni–Sb–Sn systems. Phase equilibria in the Ni–Sn–Sb system at 450°C were established by means of Electron Probe Microanalysis (EPMA) and X-ray Powder Diffraction (XPD). With rather small cages Ni4(Sb,Sn)12, the Ba–Ni–Sn–Sb skutterudite system is perfectly suited to study the influence of filler atomsmore » on the phonon thermal conductivity. Single-phase samples with the composition Ni4Sb8.2Sn3.8, Ba0.42Ni4Sb8.2Sn3.8 and Ba0.92Ni4Sb6.7Sn5.3 were used to measure their physical properties, i.e. temperature dependent electrical resistivity, Seebeck coefficient and thermal conductivity. The resistivity data demonstrate a crossover from metallic to semiconducting behaviour. The corresponding gap width was extracted from the maxima in the Seebeck coefficient data as a function of temperature. Single crystal X-ray structure analyses at 100, 200 and 300 K revealed the thermal expansion coefficients as well as Einstein and Debye temperatures for Ba0.73Ni4Sb8.1Sn3.9 and Ba0.95Ni4Sb6.1Sn5.9. These data were in accordance with the Debye temperatures obtained from the specific heat (4.4 K < T < 140 K) and Mössbauer spectroscopy (10 K < T < 290 K). Rather small atom displacement parameters for the Ba filler atoms indicate a severe reduction in the “rattling behaviour” consistent with the high levels of lattice thermal conductivity. The elastic moduli, collected from Resonant Ultrasonic Spectroscopy ranged from 100 GPa for Ni4Sb8.2Sn3.8 to 116 GPa for Ba0.92Ni4Sb6.7Sn5.3. The thermal expansion coefficients were 11.8 × 10-6 K-1 for Ni4Sb8.2Sn3.8 and 13.8 × 10-6 K-1 for Ba0.92Ni4

  5. Brazing ZrO{sub 2} ceramic to Ti6Al4V 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 Ti6Al4V alloy was achieved using NiCrSiB amorphous filler foil. The interfacial microstructure of ZrO{sub 2}/Ti6Al4V 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 Ti6Al4V 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/Widmansttten 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}/?/Widmansttten structure. The formation of TiO produced the darkening effect of ZrO{sub 2} ceramic. The highest joining strength of 284.6MPa was obtained.

  6. Hierarchical Na-doped cubic ZrO{sub 2} synthesis by a simple hydrothermal route and its application in biodiesel production

    SciTech Connect (OSTI)

    Lara-Garca, Hugo A.; Romero-Ibarra, Issis C.; Pfeiffer, Heriberto

    2014-10-15

    Hierarchical growth of cubic ZrO{sub 2} phase was successfully synthesized via a simple hydrothermal process in the presence of different surfactants (cationic, non-ionic and anionic) and sodium hydroxide. The structural and microstructural characterizations of different ZrO{sub 2} powders were performed using various techniques, such as X-ray diffraction, transmission electron microscopy, N{sub 2} adsorptiondesorption, scanning electron microscopy and infrared. Results indicated that sodium addition stabilized the cubic ZrO{sub 2} phase by a Na-doping process, independently of the surfactant used. In contrast, microstructural characteristics varied as a function of the surfactant and sodium presence. In addition, water vapor (H{sub 2}O) and carbon dioxide (CO{sub 2}) sorption properties were evaluated on ZrO{sub 2} samples. Results evidenced that sample surface reactivity changed as a function of the sodium content. Finally, this surface reactivity was evaluated on the biodiesel transesterification reaction using the different synthesized samples, obtaining yields of 93%. - Graphical abstract: Hierarchical growth of cubic Na-ZrO{sub 2} phase was synthesized by hydrothermal processes in the presence of surfactants and sodium. Sodium addition stabilized the cubic phase by a Na-doping process, while the microstructural characteristics varied with surfactants. Finally, this surface reactivity was evaluated on the biodiesel transesterification reaction. - Highlights: Cubic-ZrO{sub 2} phase was synthesized via a simple hydrothermal process. ZrO{sub 2} structure and microstructures changed as a function of the surfactant. Cubic-ZrO{sub 2} phase was evaluated on the biodiesel transesterification reaction.

  7. Develop Roll-to-Roll Manufacturing Process of ZrO2 Nanocrystals/Acrylic Nanocomposites for High Refractive Index Applications

    SciTech Connect (OSTI)

    Joshi, Pooran C.; Compton, Brett G.; Li, Jianlin; Jellison, Jr, Gerald Earle; Duty, Chad E; Chen, Zhiyun

    2015-04-01

    The purpose of this Cooperative Research and Development Agreement (CRADA) was to develop and evaluate ZrO2/acrylic nanocomposite coatings for integrated optoelectronic applications. The formulations engineered to be compatible with roll-to-roll process were evaluated in terms of optical and dielectric properties. The uniform distribution of the ZrO2 nanocrystals in the polymer matrix resulted in highly tunable refractive index and dielectric response suitable for advanced photonic and electronic device applications.

  8. Cs{sub 3}Zr{sub 6}Br{sub 15}Z (Z = C, B): A stuffed rhombohedral perovskite structure of linked clusters

    SciTech Connect (OSTI)

    Qi, Ru-Yi; Corbett, J.D.

    1995-03-29

    The isostructural title compounds are synthesized in good yields form reactions of Zr, ZrBr{sub 4}, CsBr, and Z in sealed Ta tubing for {approximately}3 weeks at 850 {degrees}C. Their single-crystal data refinements established the products as Cs{sub 3.02(7)-}Zr{sub 6}Br{sub 14}C and Cs{sub 3.39(5)}Zr{sub 6}br{sub 15}B (R3c, Z = 6, a = 13.1031 (6), 13.116(1) {angstrom}, c = 35.800(3), 35.980(6) {angstrom}, R(F)/R{sub w} = 5.4/5.9, 5.4/4.4%, respectively). The structure is derived form a three-dimensional [Zr{sub 6}(Z)Br{sub 12}]Br{sub 6/2} network of four-rings (as in ReO{sub 6/2}) twisted into a rhombohedral perovskite analogous to VF{sub 3}. The three necessary Cs{sup +} cations are fractionally distributed over five sites that are far from optimal or common, with either eight asymmetric or only three close bromide neighbors. Refinement of a third Cs{sub 3.18(5)}Zr{sub 6}Br{sub 15}C structure at {minus}50 {degrees}C gave the same result with somewhat smaller positional distributions of the atoms.

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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. α-Fe layers exhibited drastically lower defect density and size than those in large α-Fe grains. In situ video revealed that mobile dislocation loops in α-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.

  14. 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

  15. Diffusion Barrier Selection from Refractory Metals (Zr, Mo and Nb) via Interdiffusion Investigation for U-Mo RERTR Fuel Alloy

    SciTech Connect (OSTI)

    K. Huang; C. Kammerer; D. D. Keiser, Jr.; Y. H. Sohn

    2014-04-01

    U-Mo alloys are being developed as low enrichment monolithic fuel under the Reduced Enrichment for Research and Test Reactor (RERTR) Program. Diffusional interactions between the U-Mo fuel alloy and Al-alloy cladding within the monolithic fuel plate construct necessitate incorporation of a barrier layer. Fundamentally, a diffusion barrier candidate must have good thermal conductivity, high melting point, minimal metallurgical interaction, and good irradiation performance. Refractory metals, Zr, Mo, and Nb are considered based on their physical properties, and the diffusion behavior must be carefully examined first with U-Mo fuel alloy. Solid-to-solid U-10wt.%Mo vs. Mo, Zr, or Nb diffusion couples were assembled and annealed at 600, 700, 800, 900 and 1000 degrees C for various times. The interdiffusion microstructures and chemical composition were examined via scanning electron microscopy and electron probe microanalysis, respectively. For all three systems, the growth rate of interdiffusion zone were calculated at 1000, 900 and 800 degrees C under the assumption of parabolic growth, and calculated for lower temperature of 700, 600 and 500 degrees C according to Arrhenius relationship. The growth rate was determined to be about 10 3 times slower for Zr, 10 5 times slower for Mo and 10 6 times slower for Nb, than the growth rates reported for the interaction between the U-Mo fuel alloy and pure Al or Al-Si cladding alloys. Zr, however was selected as the barrier metal due to a concern for thermo- mechanical behavior of UMo/Nb interface observed from diffusion couples, and for ductile-to-brittle transition of Mo near room temperature.

  16. 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.

  17. Efficient photoluminescence of Dy{sup 3+} at low concentrations in nanocrystalline ZrO{sub 2}

    SciTech Connect (OSTI)

    Diaz-Torres, L.A.; Rosa, E. de la Salas, P.; Romero, V.H.; Angeles-Chavez, C.

    2008-01-15

    Nanocrystalline ZrO{sub 2}:Dy{sup 3+} were prepared by sol-gel and the structural and photoluminescence properties characterized. The crystallite size ranges from 20 to 50 nm and the crystalline phase is a mixture of tetragonal and monoclinic structure controlled by dopant concentration. Strong white light produced by the host emission band centered at {approx}460 nm and two strong Dy{sup 3+} emission bands, blue (488 nm) and yellow (580 nm), under direct excitation at 350 nm were observed. The highest efficiency was obtained for 0.5 mol% of Dy{sup 3+}. Emission is explained in terms of high asymmetry of the host suggesting that Dy{sup 3+} are substituted mainly into Zr{sup 4+} lattice sites at the crystallite surface. Luminescence quenching is explained in terms of cross-relaxation of intermediate Dy{sup 3+} levels. - Graphical abstract: White light emission from {approx}70 nm ZrO{sub 2}:Dy{sup 3+} nanocrystals. The highest efficiency was obtained for 0.5 mol% of dopant and the dominant crystalline structure was monoclinic.

  18. Homogeneous hydride formation path in α-Zr: Molecular dynamics simulations with the charge-optimized many-body potential

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

    Zhang, Yongfeng; Bai, Xian-Ming; Yu, Jianguo; Tonks, Michael R.; Noordhoek, Mark J.; Phillpot, Simon R.

    2016-06-01

    A formation path for homogeneous γ hydride formation in hcp α-Zr, from solid solution to the ζ and then the γ hydride, was demonstrated using molecular static calculations and molecular dynamic simulations with the charge-optimized many-body (COMB) potential. Hydrogen has limited solubility in α-Zr. Once the solubility limit is exceeded, the stability of solid solution gives way to that of coherent hydride phases such as the ζ hydride by planar precipitation of hydrogen. At finite temperatures, the ζ hydride goes through a partial hcp-fcc transformation via 1/3 <1¯100> slip on the basal plane, and transforms into a mixture of γmore » hydride and α-Zr. In the ζ hydride, slip on the basal plane is favored thermodynamically with negligible barrier, and is therefore feasible at finite temperatures without mechanical loading. The transformation process involves slips of three equivalent shear partials, in contrast to that proposed in the literature where only a single shear partial was involved. The adoption of multiple slip partials minimizes the macroscopic shape change of embedded hydride clusters and the shear strain accumulation in the matrix, and thus reduces the overall barrier needed for homogeneous γ hydride formation. In conclusion, this formation path requires finite temperatures for hydrogen diffusion without mechanical loading. Therefore, it should be effective at the cladding operating conditions.« less

  19. 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

  20. Effect of Gd and Zr co-substitution on multiferroic properties of BiFeO{sub 3}

    SciTech Connect (OSTI)

    Arora, Manisha Sati, Prakash Chandra Kumar, Manoj

    2014-04-24

    Single phase Bi{sub 1−x}Gd{sub x}Fe{sub 1−y}Zr{sub y}O{sub 3} (x=0.06;y=0, x= 0.10, y=0 and x=0.10,y= 0.03) nanoparticles were prepared to study the combined effect of Gd and Zr substitution on structural, magnetic and optical properties of BiFeO3. Rietveld refinement of X-ray diffraction patterns predicted that sample with x=0.06, y=0 was indexed to rhombohedral structure while samples with x=0.10, y=0 and x=0.10, y=0.03 were crystallized in multiphase (rhombohedral + orthorhombic). Magnetic properties were significantly enhanced with increasing concentration of Gd ions, however, magnetization reduced slightly with addition of 3% Zr ions in the system. Electron spin Resonance analysis indicated that breaking of spin cycloid is the main reason for enhancement of magnetization. Optical properties were investigated and direct band gap was found for all the samples.

  1. Preparation, photoluminescent properties and luminescent dynamics of BaAlF{sub 5}:Eu{sup 2+} nanophosphors

    SciTech Connect (OSTI)

    Zhang, Wei; Hua, Ruinian; Liu, Tianqing; Zhao, Jun; Na, Liyan; Chen, Baojiu

    2014-12-15

    Graphical abstract: Rice-shaped BaAlF{sub 5}:Eu{sup 2+} nanophosphors were synthesized via one-pot hydrothermal process. The as-prepared BaAlF{sub 5}:Eu{sup 2+} are composed of many particles with an average diameter of 40 nm. When excited at 260 nm, the sharp line emission located at 361 nm of Eu{sup 2+} was observed. The optimum doping concentration of Eu{sup 2+} was confirmed to be 5 mol%. The strong ultraviolet emission of Eu{sup 2+} ions in BaAlF{sub 5}:Eu{sup 2+} nanoparticles suggests that these nanoparticles may have potential applications for sensing, solid-state lasers and spectrometer calibration. - Highlights: • BaAlF{sub 5}:Eu{sup 2+} nanophosphors were synthesized via a mild hydrothermal process. • The Van and Huang models were used to research the mechanism of concentration quenching. • The optimum doping concentration of Eu2+ was confirmed to be 5 mol%. - Abstract: Eu{sup 2+}-doped BaAlF{sub 5} nanophosphors were synthesized via a facile one-pot hydrothermal method. The final products were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and photoluminescence (PL) spectroscopy. XRD results showed that the prepared samples are single-phase. The FE-SEM and TEM images indicated that the prepared BaAlF{sub 5}:Eu{sup 2+} nanophosphors are composed of many rice-shaped particles with an average diameter of 40 nm. When excited at 260 nm, BaAlF{sub 5}:Eu{sup 2+} nanophosphors exhibit the sharp line emissions of Eu{sup 2+} at room temperature. The optimum doping concentration of Eu{sup 2+} was confirmed to be 5 mol%. The Van and Huang models were used to study the mechanism of concentration quenching and the electric dipole–dipole interaction between Eu{sup 2+} can be deduced to be a dominant for quenching fluorescence in BaAlF{sub 5}:Eu{sup 2+} nanophosphors. The strong ultraviolet emission of Eu{sup 2+} in BaAlF{sub 5}:Eu{sup 2+} nanophosphors suggests that

  2. Robust antiferromagnetism preventing superconductivity in pressurized (Ba0.61K0.39)Mn2Bi2

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

    Gu, Dachun; Dai, Xia; Le, Congcong; Sun, Liling; Wu, Qi; Saparov, Bayrammurad; Guo, Jing; Gao, Peiwen; Zhang, Shan; Zhou, Yazhou; et al

    2014-12-05

    BaMn2Bi2 possesses an iso-structure of iron pnictide superconductors and similar antiferromagnetic (AFM) ground state to that of cuprates, therefore, it receives much more attention on its properties and is expected to be the parent compound of a new family of superconductors. When doped with potassium (K), BaMn2Bi2 undergoes a transition from an AFM insulator to an AFM metal. Consequently, it is of great interest to suppress the AFM order in the K-doped BaMn2Bi2 with the aim of exploring the potential superconductivity. Here, we report that external pressure up to 35.6 GPa cannot suppress the AFM order in the K-doped BaMn2Bi2more » to develop superconductivity in the temperature range of 300 K–1.5 K, but induces a tetragonal (T) to an orthorhombic (OR) phase transition at ~20 GPa. Theoretical calculations for the T and OR phases, on basis of our high-pressure XRD data, indicate that the AFM order is robust in the pressurized Ba0.61K0.39Mn2Bi2. Utlimately, both of our experimental and theoretical results suggest that the robust AFM order essentially prevents the emergence of superconductivity.« less

  3. Facile synthesis of Ba1-xKxFe?As? superconductors via hydride route

    SciTech Connect (OSTI)

    Zaikina, Julia V. [Univ. of California at Davis, Davis, CA (United States); Batuk, Maria [Univ. of Antwerp, Antwerp (Belgium); Abakumov, Artem M. [Univ. of Antwerp, Antwerp (Belgium); Navrotsky, Alexandra [Univ. of California at Davis, Davis, CA (United States); Kauzlarich, Susan M. [Univ. of California at Davis, Davis, CA (United States)

    2014-12-03

    We have developed a fast, easy, and scalable synthesis method for Ba1-xKxFe?As? (0 ? x ? 1) superconductors using hydrides BaH? and KH as a source of barium and potassium metals. Synthesis from hydrides provides better mixing and easier handling of the starting materials, consequently leading to faster reactions and/or lower synthesis temperatures. The reducing atmosphere provided by the evolved hydrogen facilitates preparation of oxygen-free powders. By a combination of methods we have shown that Ba1-xKxFe?As? obtained via hydride route has the same characteristics as when it is prepared by traditional solid-state synthesis. Refinement from synchrotron powder X-ray diffraction data confirms a linear dependence of unit cell parameters upon K content as well as the tetragonal to orthorhombic transition at low temperatures for compositions with x < 0.2. Magnetic measurements revealed dome-like dependence of superconducting transition temperature Tc upon K content with a maximum of 38 K for x close to 0.4. Electron diffraction and high-resolution high-angle annular dark-field scanning transmission electron microscopy indicates an absence of Ba/K ordering, while local inhomogeneity in the Ba/K distribution takes place at a scale of several angstroms along [110] crystallographic direction.

  4. Analysis of BaBar data for three meson tau decay modes using the Tauola generator

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

    Shekhovtsova, Olga

    2014-11-24

    The hadronic current for the τ⁻ → π⁻π⁺π⁻ντ decay calculated in the framework of the Resonance Chiral Theory with an additional modification to include the σ meson is described. In addition, implementation into the Monte Carlo generator Tauola and fitting strategy to get the model parameters using the one-dimensional distributions are discussed. The results of the fit to one-dimensional mass invariant spectrum of the BaBar data are presented.

  5. Analysis of BaBar data for three meson tau decay modes using the Tauola generator

    SciTech Connect (OSTI)

    Shekhovtsova, Olga

    2014-11-24

    The hadronic current for the τ⁻ → π⁻π⁺π⁻ντ decay calculated in the framework of the Resonance Chiral Theory with an additional modification to include the σ meson is described. In addition, implementation into the Monte Carlo generator Tauola and fitting strategy to get the model parameters using the one-dimensional distributions are discussed. The results of the fit to one-dimensional mass invariant spectrum of the BaBar data are presented.

  6. As-cast microstructures in U-Pu-Zr alloy fuel pins with 5-8 wt% minor actinides and 0-1.5 wt% rare-earth elements

    SciTech Connect (OSTI)

    Dawn E. Janney; J. Rory Kennedy

    2010-11-01

    The Idaho National Laboratory (INL) is investigating U–Pu–Zr alloys with low concentrations of minor actinides (Np and Am) and rare-earth elements (La, Ce, Pr, and Nd) as possible nuclear fuels to be used to transmute minor actinides. Alloys with compositions 60U–20Pu– 3Am–2Np–15Zr, 42U–30Pu–5Am–3Np–20Zr, 59U–20Pu–3Am–2Np–1RE–15Zr, 58.5U–20Pu– 3Am–2Np–1.5RE–15Zr, 41U–30Pu–5Am–3Np–1RE–20Zr, and 40.5U–30Pu–5Am–3Np–1.5RE– 20Zr (where numbers represent weight percents of each element and RE is a rare-earth alloy consisting of 6% La, 16% Pr, 25% Ce, and 53% Nd by weight) were arc-melted and vacuum cast as fuel pins approximately 4 mmin diameter. The as-cast pins were sectioned, polished, and examined by scanning electron microscopy. Each alloy contains high-Zr inclusions surrounded by a high-actinide matrix. Alloys with rare-earth elements also contain inclusions that are high in these elements. Within the matrix, concentrations of U and Zr vary inversely, while concentrations of Np and Pu appear approximately constant. Am occurs in the matrix and with some high-rare-earth inclusions, and occasionally as high-Am inclusions in samples without rare-earth elements.

  7. 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.

  8. Microstructure and Mechanical Properties of Laves Phase-strengthened Fe-Cr-Zr Alloys

    SciTech Connect (OSTI)

    Tan, Lizhen; Yang, Ying

    2014-12-05

    Laves phase-reinforced alloys have shown some preliminary promising performance at room temperatures. This paper aims at evaluating mechanical properties of Laves phase-strengthened alloys at elevated temperatures. Three Fe-Cr-Zr alloys were designed to favor the formation of eutectic microstructures containing Laves and body-centered cubic phases with the aid of thermodynamic calculations. Microstructural characterization was carried out on the alloys in as-processed and aged states using optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction. The effect of thermal aging and alloy composition on microstructure has been discussed based on microstructural characterization results. Mechanical properties have been evaluated by means of Vickers microhardness measurements, tensile testing at temperatures up to 973.15 K (700.15 °C), and creep testing at 873.15 K (600.15 °C) and 260 MPa. Alloys close to the eutectic composition show significantly superior strength and creep resistance compared to P92. Finally, however, their low tensile ductility may limit their applications at relatively low temperatures.

  9. Elastic Properties of the Solid Electrolyte Li7La3Zr2O12 (LLZO)

    SciTech Connect (OSTI)

    Yu, Seungho; Schmidt, Robert D.; Garcia-mendez, Regina; Herbert, Erik G.; Dudney, Nancy J.; Wolfenstine, Jeff; Sakamoto, Jeff; Seigel, Donald

    2015-12-16

    The oxide known as LLZO, with nominal composition Li7La3Zr2O12, is a promising solid electrolyte for Li-based batteries due to its high Li-ion conductivity and chemical stability with respect to lithium. Solid electrolytes may also enable the use of metallic Li anodes by serving as a physical barrier that suppresses dendrite initiation and propagation during cycling. Prior linear elasticity models of the Li electrode/solid electrolyte interface suggest that the stability of this interface is highly dependent on the elastic properties of the solid separator. For example, dendritic suppression is predicted to be enhanced as the electrolyte s shear modulus increases. In the present study a combination of first-principles calculations, acoustic impulse excitation measurements, and nanoindentation experiments are used to determine the elastic constants and moduli for highconductivity LLZO compositions based on Al and Ta doping. The calculated and measured isotropic shear moduli are in good agreement and fall within the range of 56-61 GPa. These values are an order of magnitude larger than that for Li metal and far exceed the minimum value ( 8.5 GPa) believed to be necessary to suppress dendrite initiation. These data suggest that LLZO exhibits sufficient stiffness to warrant additional development as a solid electrolyte for Li batteries.

  10. 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.

  11. Accelerated development of Zr-containing new generation ferritic steels for advanced nuclear reactors

    SciTech Connect (OSTI)

    Tan, Lizhen; Yang, Ying; Sridharan, K.

    2015-12-01

    The mission of the Nuclear Energy Enabling Technologies (NEET) program is to develop crosscutting technologies for nuclear energy applications. Advanced structural materials with superior performance at elevated temperatures are always desired for nuclear reactors, which can improve reactor economics, safety margins, and design flexibility. They benefit not only new reactors, including advanced light water reactors (LWRs) and fast reactors such as the sodium-cooled fast reactor (SFR) that is primarily designed for management of high-level wastes, but also life extension of the existing fleet when component exchange is needed. Developing and utilizing the modern materials science tools (experimental, theoretical, and computational tools) is an important path to more efficient alloy development and process optimization. The ultimate goal of this project is, with the aid of computational modeling tools, to accelerate the development of Zr-bearing ferritic alloys that can be fabricated using conventional steelmaking methods. The new alloys are expected to have superior high-temperature creep performance and excellent radiation resistance as compared to Grade 91. The designed alloys were fabricated using arc-melting and drop-casting, followed by hot rolling and conventional heat treatments. Comprehensive experimental studies have been conducted on the developed alloys to evaluate their hardness, tensile properties, creep resistance, Charpy impact toughness, and aging resistance, as well as resistance to proton and heavy ion (Fe2+) irradiation.

  12. Structure and Stoichiometry in Supervalent Doped Li7La3 Zr2O12

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

    Mukhopadhyay, Saikat; Thompson, Travis; Sakamoto, Jeff; Huq, Ashfia; Wolfenstine, Jeff; Allen, Jan L.; Bernstein, Noam; Stewart, Derek A.; Johannes, M. D.

    2015-04-20

    The oxide garnet material Li7La3 Zr2O12 shows remarkably high ionic conductivity when doped with supervalent ions that are charge compensated by Li vacancies and is currently one of the best candidates for development of a technologically relevant solid electrolyte. Determination of optimal dopant concentration, however, has remained a persistent problem due to the extreme difficulty of establishing the actual (as compared to nominal) stoichiometry of intentionally doped materials and by the fact that it is still not entirely clear what level of lattice expansion/contraction best promotes. ionic diffusion. By combining careful synthesis, neutron diffraction, high-resolution X-ray diffraction (XRD), Raman measurements,more » and density functional theory calculations, we show that structure and stoichiometry are intimately related such that the former can in many cases be used as a gauge of the latter. We show that different Li-vacancy creating supervalent ions (Al3+ vs Ta5+) affect the structure very differently, both in terms of the lattice constant, which is easily measurable, and hi terms of the local structure, which can be difficult or impossible to access experimentally but may have important ramifications for conduction. We carefully correlate the lattice constant to dopant type/concentration via Vegard's law and then further correlate these quantities to relevant local structural parameters. In conclusion, our work opens the possibility of developing a codopant scheme that optimizes the Li vacancy concentration and the lattice size simultaneously.« less

  13. Elastic Properties of the Solid Electrolyte Li7La3Zr2O12 (LLZO)

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

    Yu, Seungho; Schmidt, Robert D.; Garcia-mendez, Regina; Herbert, Erik G.; Dudney, Nancy J.; Wolfenstine, Jeff; Sakamoto, Jeff; Seigel, Donald

    2015-12-16

    The oxide known as LLZO, with nominal composition Li7La3Zr2O12, is a promising solid electrolyte for Li-based batteries due to its high Li-ion conductivity and chemical stability with respect to lithium. Solid electrolytes may also enable the use of metallic Li anodes by serving as a physical barrier that suppresses dendrite initiation and propagation during cycling. Prior linear elasticity models of the Li electrode/solid electrolyte interface suggest that the stability of this interface is highly dependent on the elastic properties of the solid separator. For example, dendritic suppression is predicted to be enhanced as the electrolyte s shear modulus increases. Inmore » the present study a combination of first-principles calculations, acoustic impulse excitation measurements, and nanoindentation experiments are used to determine the elastic constants and moduli for highconductivity LLZO compositions based on Al and Ta doping. The calculated and measured isotropic shear moduli are in good agreement and fall within the range of 56-61 GPa. These values are an order of magnitude larger than that for Li metal and far exceed the minimum value ( 8.5 GPa) believed to be necessary to suppress dendrite initiation. These data suggest that LLZO exhibits sufficient stiffness to warrant additional development as a solid electrolyte for Li batteries.« less

  14. Prediction of magnetic moment collapse in ZrFe{sub 2} under hydrostatic pressure

    SciTech Connect (OSTI)

    Zhang, Wenxu; Zhang, Wanli

    2015-04-28

    Electronic structure and magnetic properties of ZrFe{sub 2} in the cubic Laves phase are investigated by calculations based on density functional theory. The magnetic moment decreases with the increase of the hydrostatic pressure in an unusual way: Two-step magnetic collapse is predicted. The first one is a continuous change from 1.53??{sub B}/Fe to 0.63??{sub B}/Fe at about 3.6?GPa, and the other is from 0.25??{sub B}/Fe to the nonmagnetic state at about 15?GPa in a first order manner under the local spin density approximation of the exchange correlation potential. A metastable state with intermediate spin moment about 0.15??{sub B}/Fe may exist before that. We understand this process by the changes of density of states during it. The magnetic moment decreases under the pressure in the vicinity of the experimental lattice constant with dlnm/dp=?0.038 GPa{sup ?1}. The spontaneous volume magnetostriction is 3.6%, which is huge enough to find potential applications in magnetostriction actuators and sensors. We suggest that the Invar effect of this compound may be understood when considering the magnetic moment variation according to the magnetostrictive model of Invar.

  15. Reaction dynamics and photochemistry of divalent systems. [Reaction of Ba with NO sub 2 , H sub 2 O, methanol, ClO sub 2 , O sub 3; photodissociation of NO sub 3 radical and OClO

    SciTech Connect (OSTI)

    Davis, H.F.

    1992-05-01

    Results are presented of molecular beam studies of bimolecular and unimolecular reactions of Ba. Chapter 1 discusses the reaction Ba + NO{sub 2}. Formation of the dominant BaO({sup 1}{Sigma}) + NO products resulted primarily from decay of long-lived Ba{sup +}NO{sub 2}{sup {minus}} collision complexes. Secondary mechanisms led to formation of forward scattered, internally excited BaO, and BaNO + O. D{sub o}(Ba-NO) = 65{plus minus}20 kcal/mol. Reactions of ground state and electronically excited Ba with water and alcohols are examined in Chapter 2. Reaction of Ba({sup 1}S) + H{sup 2}O led to BaO + H{sub 2}, whereas excited state Ba({sup 1}D) + H{sub 2}O reacted to form BaOH + H. Collisions between Ba and CH{sub 3}OH led to BaOCH{sub 3} + H. Radical channels involve H-atom migration and are promoted by excitation of the incident Ba atom. In Chapter 3, reactions of Ba({sup 1}S) with ClO{sub 2}2 and O{sub 3} are discussed. Again, direct and complex mechanisms were observed. Formation of BaCl + O{sub 2} from decomposition of Ba{sup +}ClO{sub 2}{sup {minus}} accounted for 10% of total reaction crass section. Although Ba + O{sub 3} {yields} BaO + 0{sub 2} occurs primarily by direct reaction mechanisms, the secondary channel Ba + 0{sub 3} {yields} BaO{sub 2} + 0 involved decay of long lived Ba{sup +}O{sub 3}{sup {minus}} intermediates. D{sub o}(Ba{minus}O{sub 2}) = 120 {plus minus}20 kcal/mol. Photodissociation dynamics of NO{sub 3} is explored in chapter 4. Visible excitation leads to formation of NO + 0{sub 2} and NO{sub 2} + O. Wavelength dependence of branching ratios is investigated. D{sub o}(O-NO{sub 2}) = 48.55 kcal/mole ;and calculate {Delta}H{sub f}(NO{sub 3}) = 17.75 kcal/mole (298K). Chapter 5 discusses the photodissociation of OClO in a molecular beam. Although ClO({sup 2}II) + O({sup 3}P) is dominant, Cl({sup 2}P) + O{sub 2} also forms, with a max yield of 3.9{plus minus}0.8% near 404nm.

  16. 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.

  17. High temperature crystal structures and superionic properties of SrCl{sub 2}, SrBr{sub 2}, BaCl{sub 2} and BaBr{sub 2}

    SciTech Connect (OSTI)

    Hull, Stephen; Norberg, Stefan T.; Ahmed, Istaq; Eriksson, Sten G.; Mohn, Chris E.

    2011-11-15

    The structural properties of the binary alkaline-earth halides SrCl{sub 2}, SrBr{sub 2}, BaCl{sub 2} and BaBr{sub 2} have been investigated from ambient temperature up to close to their melting points, using the neutron powder diffraction technique. Fluorite-structured SrCl{sub 2} undergoes a gradual transition to a superionic phase at 900-1100 K, characterised by an increasing concentration of anion Frenkel defects. At a temperature of 920(3) K, the tetragonal phase of SrBr{sub 2} undergoes a first-order transition to a cubic fluorite phase. This high temperature phase shows the presence of extensive disorder within the anion sublattice, which differs from that found in superionic SrCl{sub 2}. BaCl{sub 2} and BaBr{sub 2} both adopt the cotunnite crystal structure under ambient conditions. BaCl{sub 2} undergoes a first-order structural transition at 917(5) K to a disordered fluorite-structured phase. The relationship between the (disordered) crystal structures and the ionic conductivity behaviour is discussed and the influence of the size of the mobile anion on the superionic behaviour is explored. - Graphical abstract: Anomalous behaviour of the lattice expansion of SrCl{sub 2} at temperatures of {approx}1000 K is associated with the gradual transition to a superionic phase, whilst SrBr{sub 2} undergoes a first-order structural transition ({beta}{yields}{alpha}) to a fluorite-structured superionic phase at 920(3) K. Highlights: > Anomalous behaviour of the lattice expansion of SrCl{sub 2} occurs at temperatures {approx}1000 K. > Crystal structure of {beta}-SrBr{sub 2} is described in detail. > On heating, SrBr{sub 2} and BaCl{sub 2} transform to a fluorite-structured superionic phase. > Temperature dependence of the BaCl{sub 2} and BaBr{sub 2} structures is presented. > Nature of the superionic phases within the alkaline-earth halides is discussed.

  18. Crystal and electronic structures of two new iron selenides: Ba{sub 4}Fe{sub 3}Se{sub 10} and BaFe{sub 2}Se{sub 4}

    SciTech Connect (OSTI)

    Berthebaud, David; Perez, Olivier; Tobola, Janusz; Pelloquin, Denis; Maignan, Antoine

    2015-10-15

    The new ternary selenides, Ba{sub 4}Fe{sub 3}Se{sub 10} and BaFe{sub 2}Se{sub 4,} were synthesized from a reaction of appropriate amounts of elements at high temperature in a silica sealed tube, and their structures were resolved using X-ray single crystal diffraction. BaFe{sub 2}Se{sub 4} crystallizes in the tetragonal space group I4/m with a=8.008(9) Å and c=5.483(3) Å as cell parameters. It is a new compound with a structure isotypical to the sulfide BaFe{sub 2}S{sub 4} which belongs to the infinitely adaptive structures series Ba{sub 1+x}Fe{sub 2}S{sub 4}. The second compound, Ba{sub 4}Fe{sub 3}Se{sub 10}, crystallizes in the monoclinic space group P2{sub 1}/n with a=8.8593(1) Å, b=8.8073(1) Å, c=12.2724(1) Å and β=109.037(6)° as cell parameters. It exhibits an original structure with a new type of iron selenide polyhedra. These data were consistent with the powder X-ray diffraction and TEM analyses. Their electronic structures point towards metallicity and electronic correlations for both selenides. - Graphical abstract: Experimental [010] oriented ED pattern and corresponding HREM image of Ba{sub 4}Fe{sub 3}Se{sub 10}. Image calculated with a focus and thickness to 15nm and 8 nm respectively is inserted. Bright contrasts are correlated to Se rows belonging to FeSe{sub 3}(Se{sub 2}){sup 2−}–FeSe{sub 6}–FeSe{sub 3}(Se{sub 2}){sup 2−} trimers. The corresponding structure projection is also shown. - Highlights: • Two new barium iron selenide compounds. • An original structure type Ba4Fe3Se10. • Electronic structure calculations.

  19. Engineered unique elastic modes at a BaTiO3/2x1-Ge(001) interface

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

    Kumah, D. P.; Dogan, M.; Ngai, J. H.; Qiu, D.; Zhang, Z.; Su, D.; Specht, E. D.; Ismail-Beigi, S.; Ahn, C. H.; Walker, F. J.

    2016-03-07

    Here, the strong interaction at an interface between a substrate and thin film leads to epitaxy and provides a means of inducing structural changes in the epitaxial film. These induced material phases often exhibit technologically relevant electronic, magnetic, and functional properties. The 2×1 surface of a Ge(001) substrate applies a unique type of epitaxial constraint on thin films of the perovskite oxide BaTiO3 where a change in bonding and symmetry at the interface leads to a non-bulk-like crystal structure of the BaTiO3. While the complex crystal structure is predicted using first-principles theory, it is further shown that the details ofmore » the structure are a consequence of hidden phases found in the bulk elastic response of the BaTiO3 induced by the symmetry of forces exerted by the germanium substrate.« less

  20. Formation of BaSi{sub 2} heterojunction solar cells using transparent MoO{sub x} hole transport layers

    SciTech Connect (OSTI)

    Du, W.; Takabe, R.; Baba, M.; Takeuchi, H.; Toko, K.; Hara, K. O.; Usami, N.; Suemasu, T.

    2015-03-23

    Heterojunction solar cells that consist of 15?nm thick molybdenum trioxide (MoO{sub x}, x?BaSi{sub 2} layers were demonstrated. Rectifying current-voltage characteristics were observed when the surface of BaSi{sub 2} was exposed to air. When the exposure time was decreased to 1?min, an open circuit voltage of 200?mV and a short circuit current density of 0.5?mA/cm{sup 2} were obtained under AM1.5 illumination. The photocurrent density under a reverse bias voltage of ?1 V reached 25?mA/cm{sup 2}, which demonstrates the significant potential of BaSi{sub 2} for solar cell applications.

  1. Long-range magnetic ordering in Ba{sub 2}CoS{sub 3}: A neutron diffraction study

    SciTech Connect (OSTI)

    Headspith, D.A. [Department of Chemistry, University of Hull, Cottingham Road, Hull HU6 7RX (United Kingdom); Battle, P.D. [Inorganic Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QR (United Kingdom); Francesconi, M.G. [Department of Chemistry, University of Hull, Cottingham Road, Hull HU6 7RX (United Kingdom)], E-mail: m.g.francesconi@hull.ac.uk

    2007-10-15

    Neutron powder diffraction has been used to determine the magnetic structure of the quasi-one-dimensional compound Ba{sub 2}CoS{sub 3}, which contains linear [001] chains of vertex-sharing CoS{sub 4} tetrahedra, spaced apart by Ba{sup 2+} cations. At 1.5 K the Co{sup 2+} cations in the chains are antiferromagnetically ordered with an ordered magnetic moment of 1.97(4) {mu}{sub B} per cation aligned along [100]. Each Co{sup 2+} cation is ferromagnetically aligned with four cation in neighbouring chains and antiferromagnetically aligned with two others. - Graphical abstract: Neutron powder diffraction has been used to prove that Ba{sub 2}CoS{sub 3} shows long-range antiferromagnetic order at low temperatures, despite the quasi-one-dimensional arrangement of the CoS{sub 4} tetrahedra in the crystal structure.

  2. Structure and transport in high pressure oxygen sputter-deposited BaSnO{sub 3−δ}

    SciTech Connect (OSTI)

    Ganguly, Koustav; Ambwani, Palak; Xu, Peng; Jeong, Jong Seok; Mkhoyan, K. Andre; Leighton, C. E-mail: leighton@umn.edu; Jalan, Bharat E-mail: leighton@umn.edu

    2015-06-01

    BaSnO{sub 3} has recently been identified as a high mobility wide gap semiconductor with significant potential for room temperature oxide electronics. Here, a detailed study of the high pressure oxygen sputter-deposition, microstructure, morphology, and stoichiometry of epitaxial BaSnO{sub 3} on SrTiO{sub 3}(001) and MgO(001) is reported, optimized conditions resulting in single-phase, relaxed, close to stoichiometric films. Most significantly, vacuum annealing is established as a facile route to n-doped BaSnO{sub 3−δ}, leading to electron densities above 10{sup 19} cm{sup −3}, 5 mΩ cm resistivities, and room temperature mobility of 20 cm{sup 2} V{sup −1} s{sup −1} in 300-Å-thick films on MgO(001). Mobility limiting factors, and the substantial scope for their improvement, are discussed.

  3. 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

    Management of the Award of a $150 Million Recovery Act Grant to LG Chem Michigan Inc. OAS-RA-13-10 February 2013 Department of Energy Washington, DC 20585 February 8, 2013 MEMORANDUM FOR THE UNDER SECRETARY OF ENERGY FROM: Gregory H. Friedman Inspector General SUBJECT: INFORMATION: Special Report on "The Department of Energy's Management of the Award of a $150 Million Recovery Act Grant to LG Chem Michigan Inc." BACKGROUND The Department of Energy's Vehicle Technologies Program was

  4. Reversible Electrochemical Insertion of Lithium into Type I Ba8AlySi46-y Clathrate

    SciTech Connect (OSTI)

    Li, Ying; Raghavan, Rahul; Wagner, Nicholas; Davidowski, Stephen; Baggetto, Loic; Zhao, Ran; Cheng, Qian; Holland, Gregory p; Yarger, Jeffery L; Veith, Gabriel M; Ellis-Terrell, Carol; Miller, Michael A; Chan, Kwai; Chan, Candace

    2015-01-01

    Silicon clathrates contain cage-like structures that can encapsulate various guest atoms or molecules. Here we present an electrochemical evaluation of type I silicon clathrates based on Ba8AlySi46-y for the anode material in lithium-ion batteries. Post-cycling characterization with NMR and XRD show no discernible structural or volume changes even after electrochemical insertion of 44 Li into the clathrate structure. The observed properties are in stark contrast with lithiation of other silicon anodes, which become amorphous and suffer from larger volume changes. The lithiation/delithiation processes are proposed to occur in single phase reactions at approximately 0.2 and 0.4 V vs. Li/Li+, respectively, distinct from other diamond cubic or amorphous silicon anodes. Reversible capacities as high as 499 mAh g-1 at a 5 mA g-1 rate were observed for silicon clathrate with composition Ba8Al8.54Si37.46, corresponding to Li:Si of 1.18:1. The results show that silicon clathrates could be promising durable anodes for lithium-ion batteries.

  5. Direct evidence of octupole deformation in neutron-rich 144Ba

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

    Bucher, B.; Zhu, S.; Wu, C. Y.; Janssens, R. V. F.; Cline, D.; Hayes, A. B.; Albers, M.; Ayangeakaa, A. D.; Butler, P. A.; Campbell, C. M.; et al

    2016-03-17

    Here, the neutron-rich nucleus 144Ba (t1/2 = 11.5 s) is expected to exhibit some of the strongest octupole correlations among nuclei with mass numbers A less than 200. Until now, indirect evidence for such strong correlations has been inferred from observations such as enhanced E1 transitions and interleaving positive- and negative-parity levels in the ground-state band. In this experiment, the octupole strength was measured directly by sub-barrier, multistep Coulomb excitation of a post-accelerated 650-MeV 144Ba beam on a 1.0–mg/cm2 208Pb target. The measured value of the matrix element, < 31–∥M(E3)∥01+ >= 0.65(+17–23) eb3/2, corresponds to a reduced B(E3) transition probabilitymore » of 48(+25–34) W.u. This result represents an unambiguous determination of the octupole collectivity, is larger than any available theoretical prediction, and is consistent with octupole deformation.« less

  6. Unit-cell thick BaTiO{sub 3} blocks octahedral tilt propagation across oxide heterointerface

    SciTech Connect (OSTI)

    Kan, Daisuke Aso, Ryotaro; Kurata, Hiroki; Shimakawa, Yuichi

    2014-05-14

    We fabricated SrRuO{sub 3}/BaTiO{sub 3}/GdScO{sub 3} heterostructures in which the BaTiO{sub 3} layer is one unit cell thick by pulsed laser deposition and elucidated how the BaTiO{sub 3} layer influences structural and magneto-transport properties of the SrRuO{sub 3} layer through octahedral connections across the heterointerface. Our X-ray-diffraction-based structural characterizations show that while an epitaxial SrRuO{sub 3} layer grown directly on a GdScO{sub 3} substrate is in the monoclinic phase with RuO{sub 6} octahedral tilts, a one-unit-cell-thick BaTiO{sub 3} layer inserted between SrRuO{sub 3} and GdScO{sub 3} stabilizes the tetragonal SrRuO{sub 3} layer with largely reduced RuO{sub 6} tilts. Our high-angle annular dark-field and annular bright-field scanning transmission electron microscopy observations provide an atomic-level view of the octahedral connections across the heterostructure and reveal that the BaTiO{sub 3} layer only one unit cell thick is thick enough to stabilize the RuO{sub 6}-TiO{sub 6} octahedral connections with negligible in-plane oxygen atomic displacements. This results in no octahedral tilts propagating into the SrRuO{sub 3} layer and leads to the formation of a tetragonal SrRuO{sub 3} layer. The magneto-transport property characterizations also reveal a strong impact of the octahedral connections modified by the inserted BaTiO{sub 3} layer on the spin-orbit interaction of the SrRuO{sub 3} layer. The SrRuO{sub 3} layer on BaTiO{sub 3}/ GdScO{sub 3} has in-plane magnetic anisotropy. This is in contrast to the magnetic anisotropy of the monoclinic SrRuO{sub 3} films on the GdScO{sub 3} substrate, in which the easy axis is ?45 to the film surface normal. Our results demonstrate that the one-unit-cell-thick layer of BaTiO{sub 3} can control and manipulate the interfacial octahedral connection closely linked to the structure-property relationship of heterostructures.

  7. Role of magnetism in superconductivity of BaFe2As2: Study of 5d Au-doped crystals

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

    Li, Li; Cao, Huibo; McGuire, Michael A.; Kim, J. S.; Stewart, G. R.; Sefat, Athena Safa

    2015-09-09

    We investigate properties of BaFe2As2 (122) single crystals upon gold doping, which is the transition metal with the highest atomic weight. The Au substitution into the FeAs-planes of 122 crystal structure (Au-122) is only possible up to a small amount of ~3%. We find that 5d is more effective in reducing magnetism in 122 than its counter 3d Cu, and this relates to superconductivity. We provide evidence of short-range magnetic fluctuations and local lattice inhomogeneities that may prevent strong percolative superconductivity in Ba(Fe1-xAux)2As2.

  8. Morphology and Composition cycle of BaO/Al2O3 NSR Catalysts during NO2

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

    Uptake and Release: A multi spectroscopy and microscopy study | Department of Energy Morphology and Composition cycle of BaO/Al2O3 NSR Catalysts during NO2 Uptake and Release: A multi spectroscopy and microscopy study Morphology and Composition cycle of BaO/Al2O3 NSR Catalysts during NO2 Uptake and Release: A multi spectroscopy and microscopy study 2005 Diesel Engine Emissions Reduction (DEER) Conference Presentations and Posters 2005_deer_kim.pdf (868.73 KB) More Documents &

  9. Preparation, characterization, magnetic susceptibility (Eu, Gd and Sm) and XPS studies of Ln{sub 2}ZrTiO{sub 7} (Ln=La, Eu, Dy and Gd)

    SciTech Connect (OSTI)

    Vijaya Kumar, B.; Velchuri, Radha; Rama Devi, V.; Sreedhar, B.; Prasad, G.; Jaya Prakash, D.; Kanagaraj, M.; Arumugam, S.; Vithal, M.

    2011-02-15

    Bulk and nanosized pyrochlore materials Ln{sub 2}ZrTiO{sub 7} (Ln=La, Eu, Dy, Gd and Sm) have been prepared by the sol-gel method. All the samples were characterized by powder X-ray diffraction, Raman and X-ray photoelectron spectroscopy. Magnetic susceptibility ({chi}) measurements of Gd{sub 2}ZrTiO{sub 7}, Sm{sub 2}ZrTiO{sub 7} and Eu{sub 2}ZrTiO{sub 7} were carried out by vibrating sample magnetometer in the temperature range 2-320 K. The variation of {chi}{sup -1} (or {chi}) with temperature of Gd{sub 2}ZrTiO{sub 7}, Sm{sub 2}ZrTiO{sub 7} and Eu{sub 2}ZrTiO{sub 7} follows the Curie law, intermediate formula and the Curie-Weiss law, respectively. From the linear portion of {chi}T vs. T{sup -1} plot of Eu{sub 2}ZrTiO{sub 7} from 2 to 15 K, the classical nearest neighbor exchange (J{sup cl}) and dipolar interactions (D{sub nn}) are obtained. The XPS of Ln{sub 2}ZrTiO{sub 7} (Ln=La, Eu, Dy and Gd) gave characteristic peaks for Ln, Ti, Zr and O. The satellite peaks are observed only for 3d La of La{sub 2}ZrTiO{sub 7}. -- Graphical abstract: Sm{sub 2}ZrTiO{sub 7} does not follow the Curie or the Curie-Weiss law. The effective magnetic moment is found to be 0.768 BM (at 300 K), which is smaller than the free ion moment 1.3-1.4 BM. Display Omitted Research Highlights: {yields} Bulk and nano Ln{sub 2}ZrTiO{sub 7} (Ln=La, Eu, Dy, Gd and Sm) have been prepared by the sol-gel method. {yields} The broad Raman lines are attributed to cation disorder and small crystallite size. {yields} XPS of Ln{sub 2}ZrTiO{sub 7} exhibit characteristic X-ray photoelectron spectral features. {yields} Magnetic moment of Gd{sub 2}ZrTiO{sub 7} is obtained from magnetic susceptibility and ESR spectra.

  10. Impact of cyclic plasma treatment on oxygen vacancy defects in TiN/HfZrO/SiON/Si gate stacks

    SciTech Connect (OSTI)

    Bhuyian, Md Nasir Uddin Misra, D.; Poddar, S.; Tapily, K.; Clark, R. D.; Consiglio, S.; Wajda, C. S.; Nakamura, G.; Leusink, G. J.

    2015-05-11

    This work evaluates the defects in HfZrO as a function of Zr addition into HfO{sub 2} and when the dielectric was subjected to a slot-plane-antenna (SPA) plasma treatment in a cyclic process to form TiN/HfZrO/SiON/Si gate stacks. The defect energy levels, estimated by temperature-dependent current-voltage measurements, suggest that Zr addition in HfO{sub 2} modifies the charge state of the oxygen vacancy formation, V{sup +}. The influence of electron affinity variation of Hf and Zr ions on the charged oxygen vacancy levels seems to have contributed to the increase in defect activation energy, E{sub a}, from 0.32 eV to 0.4 eV. The cyclic SPA plasma exposure further reduces the oxygen vacancy formation because of the film densification. When the dielectric was subjected to a constant voltage stress, the charge state oxygen vacancy formation changes to V{sup 2+} and improvement was eliminated. The trap assisted tunneling behavior, as observed by the stress induced leakage current characteristics, further supports the oxygen vacancy formation model.

  11. 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.

  12. 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 spinlattice 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 spinlattice 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.

  13. Hydrothermal synthesis and afterglow luminescence properties of hollow SnO{sub 2}:Sm{sup 3+},Zr{sup 4+} spheres for potential application in drug delivery

    SciTech Connect (OSTI)

    Feng, Pengfei; Zhang, Jiachi Qin, Qingsong; Hu, Rui; Wang, Yuhua

    2014-02-01

    Highlights: We designed a novel afterglow labeling material SnO{sub 2}:Sm{sup 3+},Zr{sup 4+} for the first time. Hollow SnO{sub 2}:Sm{sup 3+},Zr{sup 4+} spheres with afterglow were prepared by hydrothermal method. Hollow SnO{sub 2}:Sm{sup 3+},Zr{sup 4+} is a potential afterglow labeling medium for drug delivery. - Abstract: A novel afterglow labeling material SnO{sub 2}:Sm{sup 3+},Zr{sup 4+} with hollow sphere shape and intense afterglow luminescence is prepared by hydrothermal method at 180 C for the first time. The morphology and the sphere growth process of this material are investigated by scanning electron microscopy in detail. The afterglow measurement shows that this hydrothermal obtained material exhibits obvious red afterglow luminescence (550700 nm) of Sm{sup 3+} which can last for 542 s (0.32 mcd/m{sup 2}). The depth of traps in this hydrothermal obtained material is calculated to be as shallow as 0.58 eV. The results demonstrate that although it is necessary to further improve the afterglow performance of the hydrothermal derived hollow SnO{sub 2}:Sm{sup 3+},Zr{sup 4+} spheres, it still can be regarded as a potential afterglow labeling medium for drug delivery.

  14. Crystal structure, short-range oxygen defects, and water adsorption in La- and Nd-modified ZrO{sub 2}

    SciTech Connect (OSTI)

    Loong, C.K.; Richardson, J.W. Jr.; Iton, L.E.; Ozawa, M.

    1995-02-01

    Doping Rare-earth (RE) elements to ZrO{sub 2} helps stabilize the cubic and tetragonal phases and improves resistance to thermal shock and sintering at high temperatures. Since a RE ion has a lower valency (3{sup +}) than Zr ion (4{sup +}), oxygen vacancies are formed to preserve electroneutrality. We have studied the crystal structure of La{sub 0.1}Zr{sub 0.9}O{sub 1.95} and Nd{sub 0.1}Zr{sub 0.9}O{sub 1.95} by neutron diffraction and examined the associated oxygen defects by a Fourier transform of the filtered residual diffuse scattering. The hydration process was investigated by inelastic neutron-scattering measurements of the hydrogen vibrational density of states of the surface hydroxyl groups and physisorbed water on these fine powders. We compare the O-H stretch vibrations for samples from with only surface hydroxyl groups to multilayer coverage of water molecules. The decreasing energies and increasing widths of the O-H stretch bands with increasing H{sub 2}O coverage indicate the influence of hydrogen bonding on the motion of water molecules. Similar elastic and inelastic experiments were also performed on a high surface-area pure ZrO{sub 2} powder.

  15. As-cast microstructures in U-Pu-Zr alloy fuel pins with 5-8 wt.% minor actinides and 0-1.5 wt% rare-earth elements

    SciTech Connect (OSTI)

    Janney, Dawn E. Kennedy, J. Rory

    2010-11-15

    The Idaho National Laboratory (INL) is investigating U-Pu-Zr alloys with low concentrations of minor actinides (Np and Am) and rare-earth elements (La, Ce, Pr, and Nd) as possible nuclear fuels to be used to transmute minor actinides. Alloys with compositions 60U-20Pu-3Am-2Np-15Zr, 42U-30Pu-5Am-3Np-20Zr, 59U-20Pu-3Am-2Np-1RE-15Zr, 58.5U-20Pu-3Am-2Np-1.5RE-15Zr, 41U-30Pu-5Am-3Np-1RE-20Zr, and 40.5U-30Pu-5Am-3Np-1.5RE-20Zr (where numbers represent weight percents of each element and RE is a rare-earth alloy consisting of 6% La, 16% Pr, 25% Ce, and 53% Nd by weight) were arc-melted and vacuum cast as fuel pins approximately 4 mm in diameter. The as-cast pins were sectioned, polished, and examined by scanning electron microscopy. Each alloy contains high-Zr inclusions surrounded by a high-actinide matrix. Alloys with rare-earth elements also contain inclusions that are high in these elements. Within the matrix, concentrations of U and Zr vary inversely, while concentrations of Np and Pu appear approximately constant. Am occurs in the matrix and with some high-rare-earth inclusions, and occasionally as high-Am inclusions in samples without rare-earth elements. - Research Highlights: {yields}Microstructures consist of high-Zr inclusions surrounded by a high-actinide matrix. {yields}Alloys with rare-earth (RE) elements contain inclusions that are high in REs. {yields}Concentrations of U and Zr vary inversely in the matrix. {yields}Am occurs in the matrix and with high-RE inclusions.

  16. Interaction between BaCO{sub 3} and OPC/BFS composite cements at 20 {sup o}C and 60 {sup o}C

    SciTech Connect (OSTI)

    Utton, C.A.; Gallucci, E.; Hill, J.; Milestone, N.B.

    2011-03-15

    A BaCO{sub 3} slurry, containing radioactive {sup 14}C, is produced during the reprocessing of spent nuclear fuel. This slurry is encapsulated in a Portland-blastfurnace slag composite cement. The effect of BaCO{sub 3} on the hydration of OPC and Portland-blastfurnace slag cements has been studied in this work. Samples containing a simulant BaCO{sub 3} slurry were cured for up to 720 days at 20 and 60 {sup o}C and analysed by XRD, SEM(EDX) and ICC. BaCO{sub 3} reacted with OPC to precipitate BaSO{sub 4} from a reaction between soluble sulfate and BaCO{sub 3}. Calcium monocarboaluminate subsequently formed from the carbonate released. The monocarboaluminate precipitated as crystals in voids formed during hydration. At 60 {sup o}C in OPC, it was not identified by XRD, suggesting the phase is unstable in this system around this temperature. In the Portland-blastfurnace slag cements containing BaCO{sub 3}, less monocarboaluminate and BaSO{sub 4} were formed, but the hydration of BFS was promoted and monocarboaluminate was stable up to 60 {sup o}C.

  17. Synthesis, Crystal and Electronic Structures of the Pnictides AE3TrPn3 (AE = Sr, Ba; Tr = Al, Ga; Pn = P, As)

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

    Stoyko, Stanislav; Voss, Leonard; He, Hua; Bobev, Svilen

    2015-09-24

    New ternary arsenides AE3TrAs3 (AE = Sr, Ba; Tr = Al, Ga) and their phosphide analogs Sr3GaP3 and Ba3AlP3 have been prepared by reactions of the respective elements at high temperatures. Single-crystal X-ray diffraction studies reveal that Sr3AlAs3 and Ba3AlAs3 adopt the Ba3AlSb3-type structure (Pearson symbol oC56, space group Cmce, Z = 8). This structure is also realized for Sr3GaP3 and Ba3AlP3. Likewise, the compounds Sr3GaAs3 and Ba3GaAs3 crystallize with the Ba3GaSb3-type structure (Pearson symbol oP56, space group Pnma, Z = 8). Both structures are made up of isolated pairs of edge-shared AlPn4 and GaPn4 tetrahedra (Pn = pnictogen, i.e.,more » P or As), separated by the alkaline-earth Sr2+ and Ba2+ cations. In both cases, there are no homoatomic bonds, hence, regardless of the slightly different atomic arrangements, both structures can be rationalized as valence-precise [AE2+]3[Tr3+][Pn3-]3, or rather [AE2+]6[Tr2Pn6]12-, i.e., as Zintl phases.« less

  18. 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.

  19. Potential variation around grain boundaries in BaSi{sub 2} films grown on multicrystalline silicon evaluated using Kelvin probe force microscopy

    SciTech Connect (OSTI)

    Baba, Masakazu; Tsukahara, Daichi; Toko, Kaoru; Hara, Kosuke O.; Usami, Noritaka; Sekiguchi, Takashi; Suemasu, Takashi

    2014-12-21

    Potential variations across the grain boundaries (GBs) in a 100?nm thick undoped n-BaSi{sub 2} film on a cast-grown multicrystalline Si (mc-Si) substrate are evaluated using Kelvin probe force microscopy (KFM). The ?-2? X-ray diffraction pattern reveals diffraction peaks, such as (201), (301), (410), and (411) of BaSi{sub 2}. Local-area electron backscatter diffraction reveals that the a-axis of BaSi{sub 2} is tilted slightly from the surface normal, depending on the local crystal plane of the mc-Si. KFM measurements show that the potentials are not significantly disordered in the grown BaSi{sub 2}, even around the GBs of mc-Si. The potentials are higher at GBs of BaSi{sub 2} around Si GBs that are formed by grains with a Si(111) face and those with faces that deviate slightly from Si(111). Thus, downward band bending occurs at these BaSi{sub 2} GBs. Minority carriers (holes) undergo a repelling force near the GBs, which may suppress recombination as in the case of undoped n-BaSi{sub 2} epitaxial films on a single crystal Si(111) substrate. The barrier height for hole transport across the GBs varies in the range from 10 to 55?meV. The potentials are also higher at the BaSi{sub 2} GBs grown around Si GBs composed of grains with Si(001) and Si(111) faces. The barrier height for hole transport ranges from 5 to 55?meV. These results indicate that BaSi{sub 2} GBs formed on (111)-dominant Si surfaces do not have a negative influence on the minority-carrier properties, and thus BaSi{sub 2} formed on underlayers, such as (111)-oriented Si or Ge and on (111)-oriented mc-Si, can be utilized as a solar cell active layer.

  20. Magnetic and nonlinear optical properties of BaTiO{sub 3} nanoparticles

    SciTech Connect (OSTI)

    Ramakanth, S.; Venugopal Rao, S.; Hamad, Syed; James Raju, K. C.

    2015-05-15

    In our earlier studies the BaTiO{sub 3} samples were processed at higher temperatures like 1000{sup o}C and explained the observed magnetism in it. It is found that the charge transfer effects are playing crucial role in explaining the observed ferromagnetism in it. In the present work the samples were processed at lower temperatures like 650{sup o}C-800{sup o}C. The carrier densities in these particles were estimated to be ∼ 10{sup 19}-10{sup 20}/cm{sup 3} range. The band gap is in the range of 2.53eV to 3.2eV. It is observed that magnetization increased with band gap narrowing. The higher band gap narrowed particles exhibited increased magnetization with a higher carrier density of 1.23×10{sup 20}/cm{sup 3} near to the Mott critical density. This hint the exchange interactions between the carriers play a dominant role in deciding the magnetic properties of these particles. The increase in charge carrier density in this undoped BaTiO{sub 3} is because of oxygen defects only. The oxygen vacancy will introduce electrons in the system and hence more charge carriers means more oxygen defects in the system and increases the exchange interactions between Ti3+, Ti4+, hence high magnetic moment. The coercivity is increased from 23 nm to 31 nm and then decreased again for higher particle size of 54 nm. These particles do not show photoluminescence property and hence it hints the absence of uniformly distributed distorted [TiO5]-[TiO6] clusters formation and charge transfer between them. Whereas these charge transfer effects are vital in explaining the observed magnetism in high temperature processed samples. Thus the variation of magnetic properties like magnetization, coercivity with band gap narrowing, particle size and charge carrier density reveals the super paramagnetic nature of BaTiO{sub 3} nanoparticles. The nonlinear optical coefficients extracted from Z-scan studies suggest that these are potential candidates for optical imaging and signal processing

  1. Generation of WO{sub 3}-ZrO{sub 2} catalysts from solid solutions of tungsten in zirconia

    SciTech Connect (OSTI)

    Cortes-Jacome, Maria A.; Angeles-Chavez, Carlos; Bokhimi, Xim; Toledo-Antonio, J.A. . E-mail: jtoledo@imp.mx

    2006-08-15

    WO{sub 3}-ZrO{sub 2} samples were obtained by precipitating zirconium oxynitrate in presence of WO{sub 4} {sup =} species in solution from ammonium metatungstate at pH=10.0. Samples were characterized by atomic absorption spectroscopy, thermal analysis, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy and energy filtered-TEM. The ammonia retained in the dried sample produced a reductive atmosphere to generate W{sup 5+} ions coexisting with W{sup 6+} ions to produce a solid solution of tungsten in the zirconia lattice to stabilize the zirconia tetragonal phase when the sample was annealed at 560 deg. C. When the sample was annealed at 800 deg. C, the W atoms near crystallite surface were oxidized to W{sup 6+}, producing patches of WO{sub 3} on the zirconia crystallite. The HR-TEM analysis confirmed the existence of the solid solution when the sample was annealed at 560 deg. C, and two types of crystalline regions were identified: One with nearly spherical morphology, an average diameter of 8 nm and the atomic distribution of tetragonal zirconia. The second one had a non-spherical morphology with well-faceted faces and dimensions larger than 30 nm, and the atom distribution of tetragonal zirconia. When samples were annealed at 800 deg. C two different zirconia crystallites were formed: Those where only part of the dissolved tungsten atoms segregated to crystallite surface producing patches of nanocrystalline WO{sub 3} on the crystallite surface of tetragonal zirconia stabilized with tungsten. The second type corresponded to monoclinic zirconia crystallites with patches of nanocrystalline WO{sub 3} on their surface. The tungsten segregation gave rise to the WO{sub 3}-ZrO{sub 2} catalysts. - Graphical abstract: WO {sub x} -ZrO{sub 2} catalysts were obtained by precipitating zirconium oxynitrate in presence of WO{sub 4} {sup =}species. Initially, the W atoms remained inside the crystallite after

  2. 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.

  3. Comparative study of local atomic structures in Zr{sub 2}Cu{sub x}Ni{sub 1−x} (x = 0, 0.5, 1) metallic glasses

    SciTech Connect (OSTI)

    Huang, Yuxiang; Huang, Li; Wang, C. Z.; Ho, K. M.; Kramer, M. J.

    2015-11-21

    Extensive analysis has been performed to understand the key structural motifs accounting for the difference in glass forming ability in the Zr-Cu and Zr-Ni binary alloy systems. Here, the reliable atomic structure models of Zr{sub 2}Cu{sub x}Ni{sub 1−x} (x = 0, 0.5, 1) are constructed using the combination of X-ray diffraction experiments, ab initio molecular dynamics simulations and a constrained reverse Monte Carlo method. We observe a systematic variation of the interatomic distance of different atomic pairs with respect to the alloy composition. The ideal icosahedral content in all samples is limited, despite the high content of five-fold symmetry motifs. We also demonstrate that the population of Z-clusters in Zr{sub 2}Cu glass is much higher than that in the Zr{sub 2}Ni and Zr{sub 2}Cu{sub 0.5}Ni{sub 0.5} samples. And Z12 〈0, 0, 12, 0〉 Voronoi polyhedra clusters prefer to form around Cu atoms, while Ni-centered clusters are more like Z11 〈0, 2, 8, 1〉 clusters, which is less energetically stable compared to Z12 clusters. These two different structural properties may account for the higher glass forming ability of Zr{sub 2}Cu alloy than that of Zr{sub 2}Ni alloy.

  4. The new Hg-rich barium indium mercurides BaIn{sub x}Hg{sub 7−x} (x=3.1) and BaIn{sub x}Hg{sub 11−x} (x=0–2.8)

    SciTech Connect (OSTI)

    Wendorff, Marco; Schwarz, Michael; Röhr, Caroline

    2013-07-15

    The title compounds BaIn{sub x}Hg{sub 7−x} (x=3.1(1)) and BaIn{sub x}Hg{sub 11−x} (x=0–2.8) were synthesized from stoichiometric ratios of the elements in Ta crucibles. Their crystal structures have been determined using single crystal X-ray data. BaIn{sub x}Hg{sub 7−x} (x=3.1(1)) crystallizes in a new structure type (orthorhombic, oC16, space group Cmmm: a=512.02(1), b=1227.68(3), c=668.61(2) pm, Z=2, R1=0.0311). In the structure, the atoms of the three crystallographically different mixed In/Hg positions form planar nets of four-, six- and eight-membered rings. These nets are shifted against each other such that the four-membered rings form empty distorted cubes. The cubes are connected via common edges, corners and folded ladders, which are also found in BaIn{sub 2}/BaHg{sub 2} (KHg{sub 2} structure type) and BaIn (α-NaHg type). The Ba atoms are centered in the eight-membered rings and exhibit an overall coordination number of 20. The [BaM{sub 20}] polyhedra and twice as many distorted [M{sub 8}] cubes tesselate the space. BaIn{sub 2.8}Hg{sub 8.2} (cubic, cP36, space group Pm3{sup ¯}m, a=961.83(1) pm, Z=3, R1=0.0243) is the border compound of the phase width BaIn{sub x}Hg{sub 11−x} of the rare BaHg{sub 11} structure type. In the structure, ideal [M{sub 8}] cubes (at the corners of the unit cell) and BaM{sub 20} polyhedra (at the edges of the unit cell) represent the building blocks comparable to the other new In mercuride. In accordance with the increased In/Hg content, additional M-pure regions appear: the center of the unit cell contains a huge [Hg(1)M(2){sub 12}M(3,4){sub 32}] polyhedron, a Hg-centered cuboctahedron of In/Hg atoms surrounded by a capped cantellated cube of 32 additional M atoms. For both structure types, the bonding situation and the ‘coloring’, i.e. the In/Hg distribution of the polyanionic network, are discussed considering the different sizes of the atoms and the charge distribution (Bader AIM charges), which have been

  5. Production of highly-enriched 134Ba for a reference material for isotope dilution mass spectrometry measurements

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

    Horkley, J. J.; Carney, K. P.; Gantz, E. M.; Davies, J. E.; Lewis, R. R.; Crow, J. P.; Poole, C. A.; Grimes, T. S.; Giglio, J. J.

    2015-03-17

    Isotope dilution mass spectrometry (IDMS) is an analytical technique capable of providing accurate and precise quantitation of trace isotope abundance and assay providing measurement uncertainties below 1 %. To achieve these low uncertainties, the IDMS method ideally utilizes chemically pure “spike” solutions that consist of a single highly enriched isotope that is well-characterized relating to the abundance of companion isotopes and concentration in solution. To address a current demand for accurate 137Cs/137Ba ratio measurements for “age” determination of radioactive 137Cs sources, Idaho National Laboratory (INL) is producing enriched 134Ba isotopes that are tobe used for IDMS spikes to accurately determinemore » 137Ba accumulation from the decay of 137Cs. The final objective of this work it to provide a homogenous set of reference materials that the National Institute of Standards and Technology can certify as standard reference materials used for IDMS. The process that was developed at INL for the separation and isolation of Ba isotopes, chemical purification of the isotopes in solution, and the encapsulation of the materials will be described.« less

  6. Production of highly-enriched 134Ba for a reference material for isotope dilution mass spectrometry measurements

    SciTech Connect (OSTI)

    Horkley, J. J.; Carney, K. P.; Gantz, E. M.; Davies, J. E.; Lewis, R. R.; Crow, J. P.; Poole, C. A.; Grimes, T. S.; Giglio, J. J.

    2015-03-17

    Isotope dilution mass spectrometry (IDMS) is an analytical technique capable of providing accurate and precise quantitation of trace isotope abundance and assay providing measurement uncertainties below 1 %. To achieve these low uncertainties, the IDMS method ideally utilizes chemically pure “spike” solutions that consist of a single highly enriched isotope that is well-characterized relating to the abundance of companion isotopes and concentration in solution. To address a current demand for accurate 137Cs/137Ba ratio measurements for “age” determination of radioactive 137Cs sources, Idaho National Laboratory (INL) is producing enriched 134Ba isotopes that are tobe used for IDMS spikes to accurately determine 137Ba accumulation from the decay of 137Cs. The final objective of this work it to provide a homogenous set of reference materials that the National Institute of Standards and Technology can certify as standard reference materials used for IDMS. The process that was developed at INL for the separation and isolation of Ba isotopes, chemical purification of the isotopes in solution, and the encapsulation of the materials will be described.

  7. Production of highly-enriched 134Ba for a reference material for isotope dilution mass spectrometry measurements

    SciTech Connect (OSTI)

    J.J. Horkley; K.P E.M. Gantz; J.E. Davis; R.R. Lewis; J.P. Crow; C.A. Poole; T.S. Grimes; J.J. Giglio

    2015-03-01

    t Isotope dilution mass spectrometry (IDMS) is an analytical technique capable of providing accurate and precise quantitation of trace isotope abundance and assay providing measurement uncertainties below 1 %. To achieve these low uncertainties, the IDMS method ideally utilizes chemically pure spike solutions that consist of a single highly enriched isotope that is well-characterized relating to the abundance of companion isotopes and concentration in solution. To address a current demand for accurate 137Cs/137Ba ratio measurements for age determination of radioactive 137Cs sources, Idaho National Laboratory (INL) is producing enriched 134Ba isotopes that are tobe used for IDMS spikes to accurately determine 137Ba accumulation from the decay of 137Cs. The final objective of this work it to provide a homogenous set of reference materials that the National Institute of Standards and Technology can certify as standard reference materials used for IDMS. The process that was developed at INL for the separation and isolation of Ba isotopes, chemical purification of the isotopes in solution,

  8. Production of highly-enriched 134Ba for a reference material for isotope dilution mass spectrometry measurements

    SciTech Connect (OSTI)

    Horkley, J. J.; Carney, K. P.; Gantz, E. M.; Davies, J. E.; Lewis, R. R.; Crow, J. P.; Poole, C. A.; Grimes, T. S.; Giglio, J. J.

    2015-03-17

    Isotope dilution mass spectrometry (IDMS) is an analytical technique capable of providing accurate and precise quantitation of trace isotope abundance and assay providing measurement uncertainties below 1 %. To achieve these low uncertainties, the IDMS method ideally utilizes chemically pure spike solutions that consist of a single highly enriched isotope that is well-characterized relating to the abundance of companion isotopes and concentration in solution. To address a current demand for accurate 137Cs/137Ba ratio measurements for age determination of radioactive 137Cs sources, Idaho National Laboratory (INL) is producing enriched 134Ba isotopes that are tobe used for IDMS spikes to accurately determine 137Ba accumulation from the decay of 137Cs. The final objective of this work it to provide a homogenous set of reference materials that the National Institute of Standards and Technology can certify as standard reference materials used for IDMS. The process that was developed at INL for the separation and isolation of Ba isotopes, chemical purification of the isotopes in solution, and the encapsulation of the materials will be described.

  9. Thermoelectric and Structural Characterization of Ba2Ho(Cu3-xCox)O6+y

    SciTech Connect (OSTI)

    Wong-Ng, W.; Li, Q.; Yang, Z.; Hu, Y.F.; Huang, Q.; Lowhorn, N.; Otani, M.; Kaduk, J.A.

    2009-03-18

    The search for thermoelectric materials for power generation and for solid-state cooling has led to increased interest of layered cobalt-containing oxides because of their thermal stability at high temperature and their desirable thermoelectric properties. This paper examines the effect of substitution of Co in the layered pervoskite Ba{sub 2}Ho(Cu{sub 3-x}Co{sub x})O{sub 6+y} (x = 0.3, 0.4, 0.5, 0.6, and 1.0). Structural analysis using the neutron Rietveld refinement technique reveals that when x {le} 0.4, Co substitutes mainly for Cu in the 'chain sites' of the Ba{sub 2}Ho(Cu{sub 3-x}Co{sub x})O{sub 6+y} structure. As x > 0.4, Co also enters in the Cu-O 'plane sites' as well. The thermoelectric properties of polycrystalline Ba{sub 2}Ho(Cu{sub 3-x}Co{sub x})O{sub 6+y} samples were studied in the temperature range of 10-390 K. In general, as the cobalt content x increases, the resistivity and Seebeck coefficient of these samples increase while the thermal conductivity decreases. Among the five Ba{sub 2}Ho(Cu{sub 3-x}Co{sub x})O{sub 6+y} compositions, the x = 0.4 member gives the highest figure of merit ZT of {approx} 0.02 at approximately 270 K.

  10. Solid solubilities of (La Nd,){sub 2}(Zr,Ti){sub 2}O{sub 7} phases deduced by neutron diffraction

    SciTech Connect (OSTI)

    Harvey, Elizabeth J.; Whittle, Karl R.; Lumpkin, Gregory R.; Smith, Ronald I.; Redfern, Simon A.T. . E-mail: satr@cam.ac.uk

    2005-03-15

    Time-of-flight powder neutron diffraction has been performed on oxides with composition (La{sub 1-x}Nd{sub x}){sub 2}Zr{sub 2}O{sub 7} and Nd{sub 2}(Zr{sub 1-x}Ti{sub x}){sub 2}O{sub 7}, where x=0, 0.2, 0.4,...1.0, in order to determine the solid solution behaviour across each series. Between La{sub 2}Zr{sub 2}O{sub 7} and Nd{sub 2}Zr{sub 2}O{sub 7}, a cubic pyrochlore phase is observed (Fd3-bar m, Z=8). A linear decrease in the lattice parameter from 10.8047 to 10.6758A indicates complete miscibility of the two end-members. For the same series, the 48f oxygen x-parameter increases from 0.3313 to 0.3348, suggesting increased distortion of the 6 coordinate B sites and reduced distortion of the 8 coordinate A sites. There is limited solubility of Nd{sub 2}Ti{sub 2}O{sub 7} in Nd{sub 2}Zr{sub 2}O{sub 7}. Exsolution of a monoclinic phase (P2{sub 1}, Z=8) rich in Nd{sub 2}Ti{sub 2}O{sub 7} is observed at approximately x=0.56. The compositional range over which a solid solution exists is more extensive than that which has been previously reported. The solubility of Nd{sub 2}Zr{sub 2}O{sub 7} in Nd{sub 2}Ti{sub 2}O{sub 7} is very low.

  11. Luminescence properties of ZrW{sub 2}O{sub 8}:Eu{sup 3+} nanophosphors for white light emitting diodes

    SciTech Connect (OSTI)

    Liao, Jinsheng Liu, Shaohua; Wen, He-Rui; Nie, Liling; Zhong, Laifu

    2015-10-15

    Highlights: • Eu{sup 3+} ions occupy C{sub 1} point group of the Zr{sup 4+} site in ZrW{sub 2}O{sub 8} crystals. • The optimum doping concentration of Eu{sup 3+} was determined for the red emission. • ZrW{sub 2}O{sub 8}:Eu possess high quantum efficiency and suitable chromaticity coordinates. - Abstract: ZrW{sub 2}O{sub 8}:Eu{sup 3+} nanophosphors (ca. 60 nm) with different Eu{sup 3+} doping concentrations were obtained using hydrothermal syntheses. X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), photoluminescence excitation and emission spectra as well as decay curve measurements were used for the characterization. Under 466 nm excitation, strong red emission at 616 nm corresponding to {sup 5}D{sub 0}–{sup 7}F{sub 2} transition of Eu{sup 3+} was observed for ZrW{sub 2}O{sub 8}:Eu{sup 3+} (9 mol%) phosphors. The values of intensity parameter Ω{sub 2} and Ω{sub 4} are 17.82 × 10{sup −20} cm{sup 2} and 1.092 × 10{sup −20} cm{sup 2}, respectively. The high quantum efficiency of 83.5% of the ZrW{sub 2}O{sub 8}:Eu{sup 3+} (9 mol%) suggests this material could be promising red phosphor for generating white light in phosphor-converted white light-emitting diodes (LED)

  12. Temperature-dependent local structural properties of redox Pt nanoparticles on TiO2 and ZrO2 supports

    SciTech Connect (OSTI)

    Jeong, Eun -Suk; Park, Chang -In; Jin, Zhenlan; Hwang, In -Hui; Son, Jae -Kwan; Kim, Mi -Young; Choi, Jae -Soon; Han, Sang -Wook

    2015-01-21

    This paper examined the local structural properties of Pt nanoparticles on SiO2, TiO2–SiO2, and ZrO2–SiO2 supports to better understand the impact of oxide-support type on the performance of Pt-based catalysts. In situ X-ray absorption fine structure (XAFS) measurements were taken for the Pt L3-edge in a temperature range from 300 to 700 K in He, H2, and O2 gas environments. The XAFS measurements demonstrated that Pt atoms were highly dispersed on TiO2–SiO2 and ZrO2–SiO2 forming pancake-shaped nanoparticles, whereas Pt atoms formed larger particles of hemispherical shapes on SiO2 supports. Contrary to the SiO2 case, the coordination numbers for Pt, Ti, and Zr around Pt atoms on the TiO2–SiO2 and ZrO2–SiO2 supports were nearly constant from 300 to 700 K under the different gas environments. These results are consistent with the improvements in thermal stability of Pt nanoparticles achieved by incorporating TiO2 or ZrO2 on the surface of SiO2 supports. XAFS analysis further indicated that the enhanced dispersion and stability of Pt were a consequence of the strong metal support interaction via Pt–Ti and Pt–Zr bonds.

  13. Temperature-dependent local structural properties of redox Pt nanoparticles on TiO2 and ZrO2 supports

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

    Jeong, Eun -Suk; Park, Chang -In; Jin, Zhenlan; Hwang, In -Hui; Son, Jae -Kwan; Kim, Mi -Young; Choi, Jae -Soon; Han, Sang -Wook

    2015-01-21

    This paper examined the local structural properties of Pt nanoparticles on SiO2, TiO2–SiO2, and ZrO2–SiO2 supports to better understand the impact of oxide-support type on the performance of Pt-based catalysts. In situ X-ray absorption fine structure (XAFS) measurements were taken for the Pt L3-edge in a temperature range from 300 to 700 K in He, H2, and O2 gas environments. The XAFS measurements demonstrated that Pt atoms were highly dispersed on TiO2–SiO2 and ZrO2–SiO2 forming pancake-shaped nanoparticles, whereas Pt atoms formed larger particles of hemispherical shapes on SiO2 supports. Contrary to the SiO2 case, the coordination numbers for Pt, Ti,more » and Zr around Pt atoms on the TiO2–SiO2 and ZrO2–SiO2 supports were nearly constant from 300 to 700 K under the different gas environments. These results are consistent with the improvements in thermal stability of Pt nanoparticles achieved by incorporating TiO2 or ZrO2 on the surface of SiO2 supports. XAFS analysis further indicated that the enhanced dispersion and stability of Pt were a consequence of the strong metal support interaction via Pt–Ti and Pt–Zr bonds.« less

  14. Microscopic description of spherical to {gamma}-soft shape transitions in Ba and Xe nuclei

    SciTech Connect (OSTI)

    Li, Z. P.; Niksic, T.; Vretenar, D.; Meng, J.

    2010-03-15

    The rapid transition between spherical and {gamma}-soft shapes in Ba and Xe nuclei in the mass region A>=130 is analyzed using excitation spectra and collective wave functions obtained by diagonalization of a five-dimensional Hamiltonian for quadrupole vibrational and rotational degrees of freedom, with parameters determined by constrained self-consistent relativistic mean-field calculations for triaxial shapes. The results reproduce the characteristic evolution of excitation spectra and E2 transition probabilities, and in general, a good agreement with available data is obtained. The calculated spectra display fingerprints of a second-order shape phase transition that can approximately be described by analytic solutions corresponding to the E(5) dynamical symmetry.

  15. Proton Form Factors And Related Processes in BaBar by ISR

    SciTech Connect (OSTI)

    Ferroli, R.B.; /Enrico Fermi Ctr., Rome /INFN, Rome

    2007-02-12

    BaBar has measured with unprecedented accuracy e{sup +}e{sup -} {yields} p{bar p} from the threshold up to Q{sub p{bar p}}{sup 2} {approx} 20 GeV{sup 2}/c{sup 4}, finding out an unexpected cross section, with plateaux and drops. In particular it is well established a sharp drop near threshold, where evidence for structures in multihadronic channels has also been found. Other unexpected and spectacular features of the Nucleon form factors are reminded, the behavior of space-like G{sub E}{sup p}/G{sub M}{sup p} and the neutron time-like form factors.

  16. Enhanced thermoelectric performance of (Ba,In) double-filled skutterudites via randomly arranged micropores

    SciTech Connect (OSTI)

    Yu, Jian; Zhao, Wen-Yu E-mail: zhangqj@whut.edu.cn; Wei, Ping; Zhu, Wan-Ting; Zhou, Hong-Yu; Liu, Zhi-Yuan; Tang, Ding-Guo; Lei, Bing; Zhang, Qing-Jie E-mail: zhangqj@whut.edu.cn

    2014-04-07

    Porous (Ba,In) double-filled skutterudite materials with pore diameter about 14??m were prepared by the decomposition of metastable ZnSb inclusions induced by the Zn sublimation. Transport measurements revealed that the Seebeck coefficient was increased due to the electron filtering effect induced by nanostructures in the surfaces of pores, the electrical conductivity was almost unchanged because of the percolation effect of conducted network composed of filled skutterudites, and the lattice thermal conductivity was dramatically suppressed due to the enhanced pore-edge boundary scattering of long-wavelength phonons. As a result, a maximum ZT of 1.36 was obtained, increased by 22.5% as compared to that of the bulk material with same chemical composition. This work demonstrates that by introducing porous structures is thought to be an efficient approach to improve the thermoelectric performance of bulk materials.

  17. Computer modeling of Y-Ba-Cu-O thin film deposition and growth

    SciTech Connect (OSTI)

    Burmester, C.; Gronsky, R. ); Wille, L. . Dept. of Physics)

    1991-07-01

    The deposition and growth of epitaxial thin films of YBa{sub 2}Cu{sub 3}O{sub 7} are modeled by means of Monte Carlo simulations of the deposition and diffusion of Y, Ba, and Cu oxide particles. This complements existing experimental characterization techniques to allow the study of kinetic phenomena expected to play a dominant role in the inherently non-equilibrium thin film deposition process. Surface morphologies and defect structures obtained in the simulated films are found to closely resemble those observed experimentally. A systematic study of the effects of deposition rate and substrate temperature during in-situ film fabrication reveals that the kinetics of film growth can readily dominate the structural formation of the thin film. 16 refs., 4 figs.

  18. Magnetic structure and spin excitations in BaMn2Bi2

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

    Calder, Stuart A.; Saparov, Bayrammurad I; Cao, H. B.; Niedziela, Jennifer L.; Lumsden, Mark D.; Sefat, Athena Safa; Christianson, Andrew D.

    2014-02-19

    We present a single crystal neutron scattering study of BaMn2Bi2, a recently synthesized material with the same ThCr2Si2type structure found in several Fe-based unconventional superconducting materials. We show long range magnetic order, in the form of a G-type antiferromagnetic structure, to exist up to 390 K with an indication of a structural transition at 100 K. Utilizing inelastic neutron scattering we observe a spin-gap of 16 meV, with spin-waves extending up to 55 meV. We find these magnetic excitations are well fit to a J1-J2-Jc Heisenberg model and present values for the exchange interactions. The spin wave spectrum appears tomore » be unchanged by the 100 K structural phase transition.« less

  19. Bose-Einstein condensation of triplons in Ba3Cr2O8

    SciTech Connect (OSTI)

    Jaime, Marcelo [Los Alamos National Laboratory; Kohama, Y [Los Alamos National Laboratory; Aczel, A [MCMASTER UNIV; Ninios, K [UNIV OF FL; Chan, H [UNIV OF FL; Balicas, L [NHMFL; Dabkowska, H [MCMASTER UNIV; Like, G [MCMASTER UNIV

    2009-01-01

    By performing heat capacity, magnetocaloric effect, torque magnetometry and force magnetometry measurements up to 33 T, we have mapped out the T-H phase diagram of the S = 1/2 spin dimer compound Ba{sub 3}Cr{sub 2}O{sub 8}. We found evidence for field-induced magnetic order between H{sub cl} = 12.52(2) T and H{sub c2} = 23.65(5) T, with the maximum transition temperature T{sub c} {approx} 2.7 K at H {approx} 18 T. The lower transition can likely be described by Bose-Einstein condensation of triplons theory, and this is consistent with the absence of any magnetization plateaus in our magnetic torque and force measurements. In contrast, the nature of the upper phase transition appears to be quite different as our measurements suggest that this transition is actually first order.

  20. Self-trapped exciton and core-valence luminescence in BaF{sub 2} nanoparticles

    SciTech Connect (OSTI)

    Vistovskyy, V. V. Zhyshkovych, A. V.; Chornodolskyy, Ya. M.; Voloshinovskii, A. S.; Myagkota, O. S.; Gloskovskii, A.; Gektin, A. V.; Vasil'ev, A. N.; Rodnyi, P. A.

    2013-11-21

    The influence of the BaF{sub 2} nanoparticle size on the intensity of the self-trapped exciton luminescence and the radiative core-valence transitions is studied by the luminescence spectroscopy methods using synchrotron radiation. The decrease of the self-trapped exciton emission intensity at energies of exciting photons in the range of optical exciton creation (h? ? E{sub g}) is less sensitive to the reduction of the nanoparticle sizes than in the case of band-to-band excitation, where excitons are formed by the recombination way. The intensity of the core-valence luminescence shows considerably weaker dependence on the nanoparticle sizes in comparison with the intensity of self-trapped exciton luminescence. The revealed regularities are explained by considering the relationship between nanoparticle size and photoelectron or photohole thermalization length as well as the size of electronic excitations.

  1. Investigation of novel decay B _____ ____(2S)____K at BaBar

    SciTech Connect (OSTI)

    Schalch, Jacob; /Oberlin Coll. /SLAC

    2011-06-22

    We investigate the undocumented B meson decay, B{sup +} {yields} {Psi}(2S){omega}K{sup +}. The data were collected with the BaBar detector at the SLAC PEP-II asymmetric-energy e{sup +}e{sup -} collier operating at the {gamma}(4S) resonance, a center-of-mass energy of 10.58 GeV/c{sup 2}. The {gamma}(4S) resonance primarily decays to pairs of B-mesons. The BaBar collaboration at the PEP-II ring was located at the SLAC National Accelerator Laboratory and was designed to study the collisions of positrons and electrons. The e{sup -}e{sup +} pairs collide at asymmetric energies, resulting in a center of mass which is traveling at relativistic speeds. The resulting time dilation allows the decaying particles to travel large distances through the detector before undergoing their rapid decays, a process that occurs in the in the center of mass frame over extremely small distances. As they travel through silicon vertex trackers, a drift chamber, a Cerenkov radiation detector and finally an electromagnetic calorimeter, we measure the charge, energy, momentum, and particle identification in order to reconstruct the decays that have occurred. While all well understood mesons currently fall into the qq model, the quark model has no a priori exclusion of higher configuration states such as qqqq which has led experimentalists and theorists alike to seek evidence supporting the existence of such states. Currently, there are hundreds of known decay modes of the B mesons cataloged by the Particle Data Group, but collectively they only account for approximately 60% of the B branching fraction and it is possible that many more exist.

  2. High temperature refractory of MgCr.sub.2 O.sub.4 matrix and unstabilized ZrO.sub.2 particles

    DOE Patents [OSTI]

    Singh, Jitendra P.; James, Jawana J.; Picciolo, John J.

    1987-01-01

    A high chromia refractory composite has been developed with improved thermal shock resistance and containing about 5-30 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 0.6-5 microns and particularly below about 3 microns with an average size in the order of 1.2-1.8 microns.

  3. Source Term Estimates of Radioxenon Released from the BaTek Medical Isotope Production Facility Using External Measured Air Concentrations

    SciTech Connect (OSTI)

    Eslinger, Paul W.; Cameron, Ian M.; Dumais, Johannes R.; Imardjoko, Yudi; Marsoem, Pujadi; McIntyre, Justin I.; Miley, Harry S.; Stoehlker, Ulrich; Widodo, Susilo; Woods, Vincent T.

    2015-10-01

    Abstract Batan Teknologi (BaTek) operates an isotope production facility in Serpong, Indonesia that supplies 99mTc for use in medical procedures. Atmospheric releases of Xe-133 in the production process at BaTek are known to influence the measurements taken at the closest stations of the International Monitoring System (IMS). The purpose of the IMS is to detect evidence of nuclear explosions, including atmospheric releases of radionuclides. The xenon isotopes released from BaTek are the same as those produced in a nuclear explosion, but the isotopic ratios are different. Knowledge of the magnitude of releases from the isotope production facility helps inform analysts trying to decide whether a specific measurement result came from a nuclear explosion. A stack monitor deployed at BaTek in 2013 measured releases to the atmosphere for several isotopes. The facility operates on a weekly cycle, and the stack data for June 15-21, 2013 show a release of 1.84E13 Bq of Xe-133. Concentrations of Xe-133 in the air are available at the same time from a xenon sampler located 14 km from BaTek. An optimization process using atmospheric transport modeling and the sampler air concentrations produced a release estimate of 1.88E13 Bq. The same optimization process yielded a release estimate of 1.70E13 Bq for a different week in 2012. The stack release value and the two optimized estimates are all within 10 percent of each other. Weekly release estimates of 1.8E13 Bq and a 40 percent facility operation rate yields a rough annual release estimate of 3.7E13 Bq of Xe-133. This value is consistent with previously published estimates of annual releases for this facility, which are based on measurements at three IMS stations. These multiple lines of evidence cross-validate the stack release estimates and the release estimates from atmospheric samplers.

  4. Magnetoinfrared spectroscopy of Landau levels and Zeeman splitting of three-dimensional massless Dirac Fermions in ZrTe5

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

    R. Y. Chen; Gu, G. D.; Chen, Z. G.; Song, X. -Y.; Schneeloch, J. A.; Wang, F.; Wang, N. L.

    2015-10-22

    We present a magnetoinfrared spectroscopy study on a newly identified three-dimensional (3D) Dirac semimetal ZrTe5. We observe clear transitions between Landau levels and their further splitting under a magnetic field. Both the sequence of transitions and their field dependence follow quantitatively the relation expected for 3D massless Dirac fermions. The measurement also reveals an exceptionally low magnetic field needed to drive the compound into its quantum limit, demonstrating that ZrTe5 is an extremely clean system and ideal platform for studying 3D Dirac fermions. The splitting of the Landau levels provides direct, bulk spectroscopic evidence that a relatively weak magnetic fieldmore » can produce a sizable Zeeman effect on the 3D Dirac fermions, which lifts the spin degeneracy of Landau levels. As a result, our analysis indicates that the compound evolves from a Dirac semimetal into a topological line-node semimetal under the current magnetic field configuration.« less

  5. High- and low-Am RE inclusion phases in a U-Np-Pu-Am-Zr alloy

    SciTech Connect (OSTI)

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

    2015-03-01

    Structural, microstructural, and microchemical data were collected from rare-earth inclusions in an as-cast U-Pu-Zr alloy with ~3 at% Am, 2% Np, and 9% rare-earth elements (La, Ce, Pr, and Nd). Two RE phases with different concentrations of Am were identified. The composition of high-Am RE inclusions is ~2-5 at% La, 15-20 % Ce, 5-10% Pr, 25-45% Nd, 1% Np, 5-10% Pu, and 10-20% Am. Some areas also have O, although this does not appear to be an essential part of the high-Am RE phase. The inclusions have a face-centered cubic structure with a lattice parameter a ~ 0.54 nm. The composition of the only low-Am RE inclusion studied in detail is ~~35-40 at% O, 40-45 % Nd, 1-2% Zr, 4-5% La, 9-10% Ce, and 6-7% Pr. This inclusion is an oxide with a crystal structure similar to the room-temperature structure of Nd2O3. Microstructural features suggest that oxidation occurred during casting, and that early crystallization of high-temperature oxides led to formation of two distinct RE phases.

  6. 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

  7. 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.

  8. High temperature oxidation behavior of austenitic stainless steel AISI 304 in steam of nanofluids contain nanoparticle ZrO2

    SciTech Connect (OSTI)

    Prajitno, Djoko Hadi Syarif, Dani Gustaman

    2014-03-24

    The objective of this study is to evaluate high temperature oxidation behavior of austenitic stainless steel SS 304 in steam of nanofluids contain nanoparticle ZrO{sub 2}. The oxidation was performed at high temperatures ranging from 600 to 800°C. The oxidation time was 60 minutes. After oxidation the surface of the samples was analyzed by different methods including, optical microscope, scanning electron microscope (SEM) and X-ray diffraction (XRD). X-ray diffraction examination show that the oxide scale formed during oxidation of stainless steel AISI 304 alloys is dominated by iron oxide, Fe{sub 2}O{sub 3}. Minor element such as Cr{sub 2}O{sub 3} is also appeared in the diffraction pattern. Characterization by optical microscope showed that cross section microstructure of stainless steel changed after oxidized with the oxide scale on the surface stainless steels. SEM and x-ray diffraction examination show that the oxide of ZrO{sub 2} appeared on the surface of stainless steel. Kinetic rate of oxidation of austenite stainless steel AISI 304 showed that increasing oxidation temperature and time will increase oxidation rate.

  9. Laser shock peening on Zr-based bulk metallic glass and its effect on plasticity: Experiment and modeling

    SciTech Connect (OSTI)

    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 the 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.

  10. Investigations of Ba{sub x}Sr{sub 1?x}TiO{sub 3} ceramics and powders prepared by direct current arc discharge technique

    SciTech Connect (OSTI)

    Li, Shuangbin; Wang, Xiaohan; Yao, Ying Jia, Yongzhong; Xie, Shaolei; Jing, Yan; Yuzyuk, Yu. I.

    2014-09-01

    Ba{sub x}Sr{sub 1?x}TiO{sub 3} ceramics with x ranging from 0 to 1 were prepared by direct current arc discharge technique and studied by means of x-ray diffraction (XRD) and Raman spectroscopy. The cubic-tetragonal ferroelectric phase transition in Ba{sub x}Sr{sub 1?x}TiO{sub 3} ceramics was found to occur at x???0.75. XRD investigation of as-grown BaTiO{sub 3} ceramics revealed co-existence of tetragonal and hexagonal modifications with a small amount of impurity phase BaTi{sub 4}O{sub 9}. No evidences of hexagonal phase were observed in Raman spectra of as-grown BaTiO{sub 3} ceramics, while Raman peaks related to hexagonal phase were clearly observed in the spectrum of fine-grain powders prepared from the same ceramics. A core-shell model for BaTiO{sub 3} ceramics prepared by direct current arc discharge technique is proposed. Absence of the hexagonal phase in any Ba{sub x}Sr{sub 1?x}TiO{sub 3} solid solution with x?

  11. Sub-10 nm lanthanide doped BaLuF{sub 5} nanocrystals: Shape controllable synthesis, tunable multicolor emission and enhanced near-infrared upconversion luminescence

    SciTech Connect (OSTI)

    Rao, Ling; Lu, Wei; Wang, Haibo; Yi, Zhigao; Zeng, Songjun; Li, Zheng

    2015-04-15

    Highlights: • Sub-10 nm cubic phase BaLuF{sub 5} nanocrystals were synthesized by a hydrothermal method for the first time. • Tunable multicolor from yellow to yellow-green was achieved by controlling Gd{sup 3+} content in BaLuF{sub 5}:Yb/Er system. • Intense near-infrared upconversion luminescence in BaLuF{sub 5}:Gd/Yb/Tm nanocrystal. • The enhancement near-infrared luminescence can be realized by adjusting the content of Gd{sup 3+} in BaLuF{sub 5}:Gd/Yb/Tm system. - Abstract: In this study, sub-10 nm BaLuF{sub 5} nanocrystals with cubic phase structure were synthesized by a solvothermal method using oleic acid as the stabilizing agent. The as-prepared BaLuF{sub 5} nanocrystals were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and analyzed by the upconversion (UC) spectra. The TEM results reveal that these samples present high uniformity. Compared with Gd-free samples, the size of BaLuF{sub 5}:Yb/Er doped with 10% Gd{sup 3+} decreased to 5.6 nm. In addition, BaLuF{sub 5}:Yb/Tm/Gd upconversion nanoparticles (UCNPs) presented efficient near-infrared (NIR)-NIR UC luminescence. Therefore, it is expected that these ultra-small BaLuF{sub 5} nanocrystals with well-controlled shape, size, and UC emission have potential applications in biomedical imaging fields.

  12. A dual chelating solgel synthesis of BaTiO{sub 3} nanoparticles with effective photocatalytic activity for removing humic acid from water

    SciTech Connect (OSTI)

    Wang, Peigong; Fan, Caimei; Wang, Yawen; Ding, Guangyue; Yuan, Peihong

    2013-02-15

    Graphical abstract: The cubic phase BaTiO{sub 3} nanoparticles can be obtained at 600 C and changed into tetragonal phase at 900 C by a dual chelating solgel method, and the photocatalytic activities of the photocatalysts calcined at different temperatures were investigated by the removal of humic acid (HA) from water under UV light irradiation. Highlights: ? The humic acid in water was firstly degradated by BaTiO{sub 3} photocatalyst. ? The cubic BaTiO{sub 3} was obtained and changed into tetragonal phase at lower temperature. ? The chelating agents had an important influence on the phase formation of BaTiO{sub 3}. ? The tetragonal phase BaTiO{sub 3} calcined at 900 C exhibited higher photocatalytic activity under UV irradiation. -- Abstract: In this paper, a dual chelating solgel method was used to synthesize BaTiO{sub 3} nanoparticles by using acetylacetone and citric acid as chelating agents. The samples calcined at different temperatures were analyzed by thermogravimetric and differential thermal analysis (TG-DTA), X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), scanning electron microscope (SEM) and UVvis diffuse reflectance spectra (UVvis). The results indicated that cubic phase BaTiO{sub 3} nanoparticles about 19.6 nm can be obtained at 600 C and changed into tetragonal phase at 900 C about 97.1 nm. All the BaTiO{sub 3} nanoparticles showed effective photocatalytic activities on the removal of humic acid (HA) under UV light irradiation. A comparison of single (acetylacetone or citric acid) and dual chelating (acetylacetone and citric acid) synthetic processes was also studied and the results demonstrated that the dual chelating agents indeed reduced phase transformation temperature from cubic to tetragonal BaTiO{sub 3}.

  13. Fast-ion conducting Y{sub 2}(Zr{sub y}Ti{sub 1-y}){sub 2}O{sub 7} pyrochlores: Neutron Rietveld analysis of disorder induced by Zr substitution

    SciTech Connect (OSTI)

    Heremans, C.; Wuensch, B.J.; Stalick, J.K.; Prince, E.

    1995-06-01

    The structure of Y{sub 2}(Zr{sub y}Ti{sub 1-y}){sub 2}O{sub 7} solid solutions progressively changes, with increasing y, from an ordered pyrochlore structure A{sub 2}B{sub 2}O{sub 7}{four_gradient}, space group Fd3m, to a deflect-fluorite structure (A,B){sub 4} (O{sub 0.875}{four_gradient}{sub 0.125}){sub 8}, space group Fm3m, at y = 0.90. The anion array consists of three independent sites O(1), O(2), and O(3), occupying positions 48f, 8a and 8b, respectively, of which 8b is unoccupied in a fully ordered pyrochlore. Rietveld powder-profile analysis of data collected with 1.5453-{angstrom} thermal neutrons was used to determine the structural state of four samples with increasing Zr content (y = 0.30, 0.45, 0.60, and 0.90). Refinements that employed only the pyrochlore superstructure intensity data provided weighted profile residuals that ranged 8.06 to 8.67% compared with expected values of 7.13 to 7.87% derived from counting statistics. The onset of disorder at y = 0.30 is marked by filling of the vacant 8b site with oxygen ions displaced from the nearest-neighbor anion shell - i.e., O(1) in 48f. Only for y > 0.45 does O(2) participate in the disorder. Mixing of the occupancy of cation sites A and B begins only with under occupancy of the O(2) site. The eight-coordinated A site, position 16c, is occupied solely by Y for y {le} 0.45 and is predominantly Y at y = 0.60. The substituted Zr{sup 4+} thus replaces Ti{sup 4+} in the six-coordinated B site for most of the solid-solution series. Complete mixing of all three cation species occurs abruptly over the narrow compositional range 0.60 < y {le} 0.90.

  14. 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.

  15. 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.

  16. Comment on Correlation and relativistic effects in U metal and U-Zr alloy: Validation of ab initio approaches

    SciTech Connect (OSTI)

    Sderlind, 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.

  17. 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 Radosavljević

    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.

  18. ABUNDANCES OF C, N, Sr, AND Ba ON THE RED GIANT BRANCH OF {omega} CENTAURI

    SciTech Connect (OSTI)

    Stanford, Laura M.; Da Costa, G. S.; Norris, John E. E-mail: gdc@mso.anu.edu.a

    2010-05-10

    Abundances relative to iron for carbon, nitrogen, strontium, and barium are presented for 33 stars on the red giant branch (RGB) of the globular cluster {omega} Centauri. They are based on intermediate-resolution spectroscopic data covering the blue spectral region analyzed using spectrum synthesis techniques. The data reveal the existence of a broad range in the abundances of these elements, and a comparison with similar data for main-sequence stars enables insight into the evolutionary history of the cluster. The majority of the RGB stars were found to be depleted in carbon, i.e., [C/Fe] < 0, while [N/Fe] for the same stars shows a range of {approx}1 dex, from [N/Fe] {approx} 0.7 to 1.7 dex. The strontium-to-iron abundance ratios varied from solar to mildly enhanced (0.0 {<=} [Sr/Fe] {<=} 0.8), with [Ba/Fe] generally equal to or greater than [Sr/Fe]. The carbon and nitrogen abundance ratios for the one known CH star in the sample, ROA 279, are [C/Fe] = 0.6 and [N/Fe] = 0.5 dex. Evidence for evolutionary mixing on the RGB is found from the fact that the relative carbon abundances on the main sequence are generally higher than those on the RGB. However, comparison of the RGB and main-sequence samples shows that the upper level of nitrogen enhancement is similar in both sets at [N/Fe] {approx} 2.0 dex. This is most likely the result of primordial rather than evolutionary mixing processes. One RGB star, ROA 276, was found to have Sr and Ba abundance ratios similar to the anomalous Sr-rich main-sequence star S2015448. High-resolution spectra of ROA 276 were obtained with the Magellan Telescope/MIKE spectrograph combination to confirm this result, revealing that ROA 276 is indeed an unusual star. For this star, calculations of the depletion effect, the potential change in surface abundance that results from the increased depth of the convective envelope as a star moves from the main sequence to the RGB, strongly suggest that the observed Sr enhancement in ROA 276 is of

  19. Effects of alloying elements on the formation of < c >-component loops in Zr alloy Excel under heavy ion irradiation.

    SciTech Connect (OSTI)

    Idrees, Yasir; Francis, Elisabeth M.; Yao, Zhongwen; Korinek, Andreas; Kirk, Marquis A.; Sattari, Mohammad; Preuss, Michael; Daymond, M. R.

    2015-05-14

    We report here the microstructural changes occurring in the zirconium alloy Excel (Zr-3.5 wt% Sn-0.8Nb-0.8Mo-0.2Fe) during heavy ion irradiation. In situ irradiation experiments were conducted at reactor operating temperatures on two Zr Excel alloy microstructures with different states of alloying elements, with the states achieved by different solution heat treatments. In the first case, the alloying elements were mostly concentrated in the beta (beta) phase, whereas, in the second case, large Zr-3(Mo,Nb,Fe)(4) secondary phase precipitates (SPPs) were grown in the alpha (alpha) phase by long term aging. The heavy ion induced damage and resultant compositional changes were examined using transmission electron microscopy (TEM) in combination with scanning transmission electron microscope (STEM)-energy dispersive x-ray spectroscopy (EDS) mapping. Significant differences were seen in microstructural evolution between the two different microstructures that were irradiated under similar conditions. Nucleation and growth of < c >-component loops and their dependence on the alloying elements are a major focus of the current investigation. It was observed that the < c >-component loops nucleate readily at 100, 300, and 400 degrees C after a threshold incubation dose (TID), which varies with irradiation temperature and the state of alloying elements. It was found that the TID for the formation of < c >-component loops increases with decrease in irradiation temperature. Alloying elements that are present in the form of SPPs increase the TID compared to when they are in the beta phase solid solution. Dose and temperature dependence of loop size and density are presented. Radiation induced redistribution and clustering of alloying elements (Sn, Mo, and Fe) have been observed and related to the formation of < c >-component loops. It has been shown that at the higher temperature tests, irradiation induced dissolution of precipitates occurs whereas irradiation induced

  20. The fluorite-pyrochlore transformation of Ho{sub 2-y}Nd{sub y}Zr{sub 2}O{sub 7}

    SciTech Connect (OSTI)

    Clements, Richard; Hester, James R.; Kennedy, Brendan J.; Ling, Chris D.; Stampfl, Anton P.J.

    2011-08-15

    Twelve members of the Ho{sub 2-y}Nd{sub y}Zr{sub 2}O{sub 7} series, prepared using conventional solid state methods, have been characterised by neutron powder diffraction. Ho{sub 2}Zr{sub 2}O{sub 7} has a defect fluorite structure whereas Nd{sub 2}Zr{sub 2}O{sub 7} is found to adopt the ordered pyrochlore structure with the composition induced fluorite-pyrochlore transformation occurring near y=1. Rietveld analysis on the neutron data for all the compositions reveals an increase in lattice parameter as a function of y across the entire series, with a small discontinuity associated with the transformation. The neutron profile results suggest that domains of pyrochlore-type initially begin to form before crystallising into a separate phase, and therefore that anion and cation ordering processes are distinct. There is a strong correlation between the extent of disorder in the anion sublattice and the x-parameter of 48f oxygen. These results point the way to a better understanding of the stability observed in pyrochlore structures. - Graphical abstract: Neutron diffraction profiles for Nd{sub 2-y}Ho{sub y}Zr{sub 2}O{sub 7} type oxides reveal details of the transformation from the ordered pyrochlore structure (y=0) to the disordered fluorite structure (y=2). Highlights: > Structures of twelve members of the Ho{sub 2-y}Nd{sub y}Zr{sub 2}O{sub 7} series studied using neutron powder diffraction. > Domains of pyrochlore-type materials form at low doping levels. > Higher doping stabilises the pyrochlore. > Anion and cation ordering processes are distinct.