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Shinsuke Yamanaka - One of the best experts on this subject based on the ideXlab platform.
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isotope effect and hydrogen content dependence on the heat capacity and thermal conductivity of zirconium hydride and Deuteride
Journal of Nuclear Science and Technology, 2016Co-Authors: Ken Kurosaki, Naoto Fujiura, Yuji Ohishi, Hiroaki Muta, Shinsuke YamanakaAbstract:Zirconium (Zr) hydride and Deuteride are considered as candidates of neutron reflector materials in fast reactors (FRs). Thus, it is important to evaluate their fundamental physical and chemical properties. In this study, we prepared ϵ-phase Zr Deuteride (ϵ-ZrD1.90), whose physical properties have been investigated and also the heat capacity (CP) and thermal conductivity (κ) have been measured from room temperature to 673 K. The obtained data were compared with the literature data of δ-phase Zr hydride (δ-ZrH1.66), ϵ-phase Zr hydride (ϵ-ZrH1.94), and Deuteride (ϵ-ZrD1.95). Both CP and κ of ϵ-ZrD1.90 were higher than those of δ-ZrH1.66. The higher CP of ϵ-ZrD1.90 than that of δ-ZrH1.66 is mainly due to the smaller vibration frequency of deuterium atoms than that of hydrogen atoms. On the other hand, the higher κ of ϵ-ZrD1.90 than that of δ-ZrH1.66 is due to the larger hydrogen isotope content of ϵ-ZrD1.90 than that of δ-ZrH1.66. The data reported here would be useful when Zr hydride and Deuteride are insta...
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the δ δ phase transition in hafnium hydride and Deuteride
Journal of Nuclear Science and Technology, 2014Co-Authors: Ken Kurosaki, Yuji Ohishi, Hiroaki Muta, Daichi Araki, Kenji Konashi, Shinsuke YamanakaAbstract:Bulk samples of hafnium (Hf) hydride and Deuteride were prepared and the thermal properties, heat capacity (CP) and thermal conductivity (κ) were measured. In the CP–temperature curves for both samples, typical lambda-type peaks were observed at around 350 K, which was due to the second-order phase transition from the δ′-phase to the δ-phase. In Hf hydride, it is considered that the δ′-phase and the δ-phase consist of regularly arranged and randomly arranged hydrogen atoms, respectively. Therefore, it can be said that the δ′/δ phase transition observed in both Hf hydride and Deuteride is an order–disorder phase transition. The values of κ as well as CP changed significantly at around the phase transition temperature.
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characteristics of zirconium hydride and Deuteride
Journal of Alloys and Compounds, 2002Co-Authors: Shinsuke Yamanaka, Ken Kurosaki, Kazuriho Yamada, Masayoshi Uno, Kiyoko Takeda, Hiroyuki Anada, Tetsushi Matsuda, S KobayashiAbstract:The electrical and thermal properties of zirconium hydride and Deuteride have been measured. The lattice parameter of δZrD2−x was smaller than that of δZrH2−x, and the Deuteride had higher elastic moduli than the hydride. The electrical and thermal conductivities of δZrH2−x were slightly different from pure Zr metal. The electronic structure of the zirconium hydride was found from XPS measurements to differ from those in the pure Zr metal, and there was a peak due to the Zr–H bond at 6.4 eV below Fermi energy in the XPS spectra. The density of states was estimated by a molecular orbital calculation, and the agreement between the XPS valence band measurements and the calculations was quite satisfactory. Some of the mechanical and thermal properties of zirconium hydride and Deuteride were interpreted in terms of the results of the molecular orbital calculation.
Hiroaki Muta - One of the best experts on this subject based on the ideXlab platform.
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isotope effect and hydrogen content dependence on the heat capacity and thermal conductivity of zirconium hydride and Deuteride
Journal of Nuclear Science and Technology, 2016Co-Authors: Ken Kurosaki, Naoto Fujiura, Yuji Ohishi, Hiroaki Muta, Shinsuke YamanakaAbstract:Zirconium (Zr) hydride and Deuteride are considered as candidates of neutron reflector materials in fast reactors (FRs). Thus, it is important to evaluate their fundamental physical and chemical properties. In this study, we prepared ϵ-phase Zr Deuteride (ϵ-ZrD1.90), whose physical properties have been investigated and also the heat capacity (CP) and thermal conductivity (κ) have been measured from room temperature to 673 K. The obtained data were compared with the literature data of δ-phase Zr hydride (δ-ZrH1.66), ϵ-phase Zr hydride (ϵ-ZrH1.94), and Deuteride (ϵ-ZrD1.95). Both CP and κ of ϵ-ZrD1.90 were higher than those of δ-ZrH1.66. The higher CP of ϵ-ZrD1.90 than that of δ-ZrH1.66 is mainly due to the smaller vibration frequency of deuterium atoms than that of hydrogen atoms. On the other hand, the higher κ of ϵ-ZrD1.90 than that of δ-ZrH1.66 is due to the larger hydrogen isotope content of ϵ-ZrD1.90 than that of δ-ZrH1.66. The data reported here would be useful when Zr hydride and Deuteride are insta...
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the δ δ phase transition in hafnium hydride and Deuteride
Journal of Nuclear Science and Technology, 2014Co-Authors: Ken Kurosaki, Yuji Ohishi, Hiroaki Muta, Daichi Araki, Kenji Konashi, Shinsuke YamanakaAbstract:Bulk samples of hafnium (Hf) hydride and Deuteride were prepared and the thermal properties, heat capacity (CP) and thermal conductivity (κ) were measured. In the CP–temperature curves for both samples, typical lambda-type peaks were observed at around 350 K, which was due to the second-order phase transition from the δ′-phase to the δ-phase. In Hf hydride, it is considered that the δ′-phase and the δ-phase consist of regularly arranged and randomly arranged hydrogen atoms, respectively. Therefore, it can be said that the δ′/δ phase transition observed in both Hf hydride and Deuteride is an order–disorder phase transition. The values of κ as well as CP changed significantly at around the phase transition temperature.
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thermophysical properties of zirconium hydride and Deuteride
Journal of Alloys and Compounds, 2004Co-Authors: Masayoshi Uno, Hiroaki Muta, Kazuhiro Yamada, Takenori Maruyama, Shusuke YamanakaAbstract:The thermophysical properties of zirconium hydride and Deuteride such as thermal, electrical and electronic properties have been studied. The thermal conductivities of zirconium hydride and Deuteride are slightly lower than that of zirconium metal, and are not strongly affected by the hydrogen content or temperature. An isotope effect in the thermal conductivity was observed, which was discussed based on the experimental values of the electrical resistivity. The electronic structure of zirconium hydride was also studied by molecular orbital calculations and by X-ray photoelectron spectroscopy (XPS) measurements.
V. N. Verbetsky - One of the best experts on this subject based on the ideXlab platform.
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Structure of (ZrTi)_0.5(VCrFe(Ni_0.9Cu_0.1))_0.5- and (ZrTi)_0.5(VMoFeNi)_0.5-Based Deuterides
Inorganic Materials, 2020Co-Authors: M. A. Sobko, V. N. Verbetsky, S. A. Lushnikov, S. S. AgafonovAbstract:— We have synthesized (ZrTi)_0.5(VCrFe(Ni_0.9Cu_0.1))_0.5 and (ZrTi)_0.5(VMoFeNi)_0.5 pseudobinary high-entropy compounds and related Deuterides. According to neutron and X-ray diffraction results, the Deuterides have the same hexagonal Laves phase structure as the parent alloys. We have determined the position of the deuterium atoms and their atomic position coordinates. The results indicate that the deuterium atoms reside predominantly in positions 24 l and 12 k _2, typical of hydrogen in hexagonal Laves phases.
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Hydriding of TiMo alloys at high hydrogen pressures
Inorganic Materials, 2016Co-Authors: S. A. Lushnikov, E. A. Movlaev, Ivan A. Bobrikov, V. G. Simkin, V. N. VerbetskyAbstract:We studied the interaction of Ti0.40Mo0.60 and Ti0.34Mo0.66 alloys with hydrogen and obtained hydrogen desorption isotherms at pressures of up to 250 MPa. At high hydrogen pressures, we observed the formation of Ti0.40Mo0.60Н1.1 and Ti0.34Mo0.66Н0.8 hydride phases. According to X-ray diffraction data, the hydrides consisted of phases with a body-centered cubic and face-centered cubic (CaF2 structure) lattices. The structure of the Deuteride based on the Ti0.40Mo0.60 alloy was studied by neutron diffraction. We identified the sites occupied by deuterium atoms and determined their occupancies.
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Crystal structure of the ZrFe_1.8Ni_0.2D_3.4 and ZrFe_1.2Ni_0.8D_3.6 Deuterides
Inorganic Materials, 2012Co-Authors: R. B. Sivov, V. A. Somenkov, V. P. Glazkov, V. N. VerbetskyAbstract:The crystal structure of the ZrFe_1.8Ni_0.2D_3.4 and ZrFe_1.2Ni_0.8D_3.6 Deuterides, which have high dissociation pressure, has been determined by neutron powder diffraction. The Deuterides have the same structure as their parent intermetallic compounds, and the deuterium atoms occupy only position 96 g in the cubic Laves phase structure C 15.
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Synthesis and structure of CeNi_3D_ x
Inorganic Materials, 2007Co-Authors: S. A. Lushnikov, V. P. Glazkov, V. N. Verbetsky, A. M. Balagurov, I. A. Bobrikov, V. A. SomenkovAbstract:We describe the synthesis of CeNi_3D_ x Deuterides at normal and high deuterium pressures. X-ray and neutron diffraction techniques were used to identify the position and determine the positional parameters of the metal and deuterium atoms. The Deuterides are isostructural with the parent compound CeNi_3 but have a larger unit cell. Increasing the deuterium content to the composition CeNi_3D_5.2 leads to partial amorphization of the material. The variation in unit-cell volume observed at low and high deuterium contents indicates that the metal-deuterium bonds are partially ionic and partially metallic.
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structure of ti zr mn v nonstoichiometric laves phases and ti0 9zr0 1 mn0 75v0 15ti0 1 2d2 8 Deuteride
Journal of Alloys and Compounds, 2003Co-Authors: S V Mitrokhin, V. A. Somenkov, V. P. Glazkov, T N Smirnova, V. N. VerbetskyAbstract:Abstract The structure of several Laves phase alloys and Deuteride was studied using methods of X-ray analysis and time-of-flight neutron diffraction. The refinement of diffraction profiles was performed using the Rietveld method. Introduction of hydrogen does not change the metal matrix structure and the hydriding is accompanied by isotropic increase of cell volume by 20%. The minimisation of the R -factor showed that the best fit is achieved for the model of deuterium location in three sites, 24(l) , 12(k) 1 and 6(h) 1 . However, at low temperature approximately 0.11 deuterium atoms relocate from the 24(l) to the 12(k) 1 position. The analysis of alloy and Deuteride structure performed in this work as well as the reference data allow to draw a conclusion, that the set of sites in hexagonal Laves phase structure which are occupied by deuterium is a stable one and does not depend on temperature or alloy composition.
Masayoshi Uno - One of the best experts on this subject based on the ideXlab platform.
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thermophysical properties of zirconium hydride and Deuteride
Journal of Alloys and Compounds, 2004Co-Authors: Masayoshi Uno, Hiroaki Muta, Kazuhiro Yamada, Takenori Maruyama, Shusuke YamanakaAbstract:The thermophysical properties of zirconium hydride and Deuteride such as thermal, electrical and electronic properties have been studied. The thermal conductivities of zirconium hydride and Deuteride are slightly lower than that of zirconium metal, and are not strongly affected by the hydrogen content or temperature. An isotope effect in the thermal conductivity was observed, which was discussed based on the experimental values of the electrical resistivity. The electronic structure of zirconium hydride was also studied by molecular orbital calculations and by X-ray photoelectron spectroscopy (XPS) measurements.
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characteristics of zirconium hydride and Deuteride
Journal of Alloys and Compounds, 2002Co-Authors: Shinsuke Yamanaka, Ken Kurosaki, Kazuriho Yamada, Masayoshi Uno, Kiyoko Takeda, Hiroyuki Anada, Tetsushi Matsuda, S KobayashiAbstract:The electrical and thermal properties of zirconium hydride and Deuteride have been measured. The lattice parameter of δZrD2−x was smaller than that of δZrH2−x, and the Deuteride had higher elastic moduli than the hydride. The electrical and thermal conductivities of δZrH2−x were slightly different from pure Zr metal. The electronic structure of the zirconium hydride was found from XPS measurements to differ from those in the pure Zr metal, and there was a peak due to the Zr–H bond at 6.4 eV below Fermi energy in the XPS spectra. The density of states was estimated by a molecular orbital calculation, and the agreement between the XPS valence band measurements and the calculations was quite satisfactory. Some of the mechanical and thermal properties of zirconium hydride and Deuteride were interpreted in terms of the results of the molecular orbital calculation.
Shusuke Yamanaka - One of the best experts on this subject based on the ideXlab platform.
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thermophysical properties of zirconium hydride and Deuteride
Journal of Alloys and Compounds, 2004Co-Authors: Masayoshi Uno, Hiroaki Muta, Kazuhiro Yamada, Takenori Maruyama, Shusuke YamanakaAbstract:The thermophysical properties of zirconium hydride and Deuteride such as thermal, electrical and electronic properties have been studied. The thermal conductivities of zirconium hydride and Deuteride are slightly lower than that of zirconium metal, and are not strongly affected by the hydrogen content or temperature. An isotope effect in the thermal conductivity was observed, which was discussed based on the experimental values of the electrical resistivity. The electronic structure of zirconium hydride was also studied by molecular orbital calculations and by X-ray photoelectron spectroscopy (XPS) measurements.