The Experts below are selected from a list of 60 Experts worldwide ranked by ideXlab platform
Yasufumi Suzuki - One of the best experts on this subject based on the ideXlab platform.
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simultaneous determination of x ray debye temperature and Gruneisen Constant for actinide dioxides puo2 and tho2
Journal of Nuclear Materials, 2000Co-Authors: Hiroyuki Serizawa, Yasuo Arai, Yasufumi SuzukiAbstract:The lattice vibrations of PuO2 and ThO2 were examined between room temperature and 1274 K using a high temperature X-ray diffractometer. The temperature factors for the metal atom, BPu and BTh in the dioxides were evaluated by the Rietveld analysis. Debye temperature was calculated using the temperature factor. It was confirmed that the Debye temperature decreased with increasing temperature. From the temperature dependence of the Debye temperature, the Gruneisen Constants were evaluated to be 1.62 for PuO2 and 1.51 for ThO2. The Debye temperatures modified for the thermal expansion of PuO2 and ThO2 were 429 and 463 K, respectively.
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x ray debye temperature and Gruneisen Constant of npo2
Journal of Alloys and Compounds, 1999Co-Authors: Hiroyuki Serizawa, Yasuo Arai, Masahide Takano, Yasufumi SuzukiAbstract:Abstract The Debye temperature, Θ D , and the Gruneisen Constant, γ , are useful parameters to estimate thermal properties of ceramics. In the present study, those for NpO 2 were determined through a high-temperature X-ray diffraction analysis. The measurements were carried out in the temperature range from room temperature up to 1174 K. The temperature factor of Np at each measured temperature was refined by Rietveld analysis to obtain Θ D , assuming that the factor of O is the same as in UO 2 . The calculated Θ D values tended to decrease with increasing temperature, which was attributed to the anharmonicity of lattice vibration. From the decrease, we determined γ using Paskin's temperature calibration which corrects the effect of anharmonicity. The values of Θ D and γ obtained in this study were 435±2 K and 1.93±0.03, respectively.
Hiroyuki Serizawa - One of the best experts on this subject based on the ideXlab platform.
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simultaneous determination of x ray debye temperature and Gruneisen Constant for actinide dioxides puo2 and tho2
Journal of Nuclear Materials, 2000Co-Authors: Hiroyuki Serizawa, Yasuo Arai, Yasufumi SuzukiAbstract:The lattice vibrations of PuO2 and ThO2 were examined between room temperature and 1274 K using a high temperature X-ray diffractometer. The temperature factors for the metal atom, BPu and BTh in the dioxides were evaluated by the Rietveld analysis. Debye temperature was calculated using the temperature factor. It was confirmed that the Debye temperature decreased with increasing temperature. From the temperature dependence of the Debye temperature, the Gruneisen Constants were evaluated to be 1.62 for PuO2 and 1.51 for ThO2. The Debye temperatures modified for the thermal expansion of PuO2 and ThO2 were 429 and 463 K, respectively.
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x ray debye temperature and Gruneisen Constant of npo2
Journal of Alloys and Compounds, 1999Co-Authors: Hiroyuki Serizawa, Yasuo Arai, Masahide Takano, Yasufumi SuzukiAbstract:Abstract The Debye temperature, Θ D , and the Gruneisen Constant, γ , are useful parameters to estimate thermal properties of ceramics. In the present study, those for NpO 2 were determined through a high-temperature X-ray diffraction analysis. The measurements were carried out in the temperature range from room temperature up to 1174 K. The temperature factor of Np at each measured temperature was refined by Rietveld analysis to obtain Θ D , assuming that the factor of O is the same as in UO 2 . The calculated Θ D values tended to decrease with increasing temperature, which was attributed to the anharmonicity of lattice vibration. From the decrease, we determined γ using Paskin's temperature calibration which corrects the effect of anharmonicity. The values of Θ D and γ obtained in this study were 435±2 K and 1.93±0.03, respectively.
Zijun Hu - One of the best experts on this subject based on the ideXlab platform.
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theoretical predictions on elastic stiffness and intrinsic thermal conductivities of yttrium silicates
Journal of the American Ceramic Society, 2014Co-Authors: Jiemin Wang, Jingyang Wang, Junning Li, Zijun HuAbstract:Yttrium silicates are promising candidates for environmental and thermal barrier coatings owing to their excellent high-temperature performances. Previous works have experimentally attested to their low thermal conductivity, nevertheless, the experimental data were significantly affected by measurement inaccuracy and the existence of defects such as point defects, dislocations, grain boundaries, and pores in measured samples. In this study, the temperature dependences of intrinsic lattice thermal conductivities of γ-Y2Si2O7 and Y2SiO5 are predicted based on the first-principles calculations of crystal structure, elastic moduli, Debye temperature, and Gruneisen Constant. Both silicates display very low thermal conductivities over the range of 300–2000 K; and in addition, Y2SiO5 exhibits relatively lower thermal conductivity than γ-Y2Si2O7. We also show certain discrepancies between experimental and theoretical thermal conductivities, and it strengthens the important role of theoretical prediction of intrinsic lattice thermal conductivities of promising materials.
Masashi Mori - One of the best experts on this subject based on the ideXlab platform.
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thermal expansion coefficient of yttria stabilized zirconia for various yttria contents
Solid State Ionics, 2005Co-Authors: Hideko Hayashi, Hideaki Inaba, Tetsuya Saitou, Naotaka Maruyama, Katsuyuki Kawamura, Masashi MoriAbstract:Abstract Thermal expansion coefficients of yttria stabilized zirconia(YSZ) with the Y 2 O 3 content of 3, 6, 8 and 10 mol% were measured using a push-rod type dilatometer in the temperature range from 103 to 876 K. The thermal expansion coefficient of YSZ decreased with the increase of the Y 2 O 3 content. The thermal expansion coefficient of YSZ was theoretically estimated for the various Y 2 O 3 contents using the values of isochoric heat capacity, molar volume, isothermal bulk modulus and the Gruneisen Constant in a good agreement with the experimental results. Among the physical properties, the bulk modulus is considered to be mainly responsible for decreasing the thermal expansion coefficient of YSZ with the increase of Y 2 O 3 content. The doping effect of Y 2 O 3 in YSZ on the thermal expansion coefficient was discussed using a molecular dynamics simulation.
Yasuo Arai - One of the best experts on this subject based on the ideXlab platform.
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simultaneous determination of x ray debye temperature and Gruneisen Constant for actinide dioxides puo2 and tho2
Journal of Nuclear Materials, 2000Co-Authors: Hiroyuki Serizawa, Yasuo Arai, Yasufumi SuzukiAbstract:The lattice vibrations of PuO2 and ThO2 were examined between room temperature and 1274 K using a high temperature X-ray diffractometer. The temperature factors for the metal atom, BPu and BTh in the dioxides were evaluated by the Rietveld analysis. Debye temperature was calculated using the temperature factor. It was confirmed that the Debye temperature decreased with increasing temperature. From the temperature dependence of the Debye temperature, the Gruneisen Constants were evaluated to be 1.62 for PuO2 and 1.51 for ThO2. The Debye temperatures modified for the thermal expansion of PuO2 and ThO2 were 429 and 463 K, respectively.
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x ray debye temperature and Gruneisen Constant of npo2
Journal of Alloys and Compounds, 1999Co-Authors: Hiroyuki Serizawa, Yasuo Arai, Masahide Takano, Yasufumi SuzukiAbstract:Abstract The Debye temperature, Θ D , and the Gruneisen Constant, γ , are useful parameters to estimate thermal properties of ceramics. In the present study, those for NpO 2 were determined through a high-temperature X-ray diffraction analysis. The measurements were carried out in the temperature range from room temperature up to 1174 K. The temperature factor of Np at each measured temperature was refined by Rietveld analysis to obtain Θ D , assuming that the factor of O is the same as in UO 2 . The calculated Θ D values tended to decrease with increasing temperature, which was attributed to the anharmonicity of lattice vibration. From the decrease, we determined γ using Paskin's temperature calibration which corrects the effect of anharmonicity. The values of Θ D and γ obtained in this study were 435±2 K and 1.93±0.03, respectively.
