Isotope Effects on Thermal Conductivity of Boron Carbide
Isotope Effects on Thermal Conductivity of Boron Carbide
复制标题
同位素对碳化硼热导率的影响
DOI：
10.1080/18811248.2002.9715210
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发表时间：
2002
影响因子：
1.2
通讯作者：
T. Nagasaki
中科院分区：
文献类型：
--
作者：
Yoshimasa Nishi;Y. Arita;T. Matsui;T. Nagasaki
同位素富集的10B4 12C圆盘样品，（10B0.75 11B0.25）4 12C，（10B0.20 11B0.80）4 12C，10B4 13C，10B4采用放电等离子烧结法制备了（12C0.50 13C0.50）、11B4（12C0.50 13C0.50）、11B4 12C、11B4 13C和天然nB4 nC。通过激光闪光法在290至1，450 K的温度范围内测量每个样品的热扩散率。从声子速度和同位素杂质对声子的散射几率两个方面讨论了同位素杂质对热导率的影响。热导率仅随硼平均质量的增加而降低。在单原子模型中，声子速度随原子质量的增加而减小。在本研究中得到的热导率被认为是独立的声子散射概率同位素杂质，但取决于声子的速度。在多晶碳化硼中，同位素效应被认为是难以检测的。
The isotopically enriched disk samples of 10B4 12C, (10B0.75 11B0.25)4 12C, (10B0.20 11B0.80)4 12C, 10B4 13C, 10B4 (12C0.50 13C0.50), 11B4 (12C0.50 13C0.50), 11B4 12C, 11B4 13C and natural nB4 nC were prepared by the spark plasma sintering method. The thermal diffusivity for each sample was measured by the laser flash method over the temperature range from 290 to 1,450 K. The isotope effects on the thermal conductivities, which were calculated from the measured thermal diffusivities, the heat capacity for natural B4C and densities, were discussed in terms of the phonon-velocity and the scattering probability of phonon by isotopic impurity. The thermal conductivity decreased only with increasing the mean mass of boron. In the single-atom model, the phonon-velocity decreases with increasing the mass of atoms. The thermal conductivity obtained in this study was seen to be independent on the scattering probability of phonon by isotopic impurity, but to depend on the phonon-velocity. Isotope effects are thought to be difficult to detect in polycrystalline boron carbide.