In the present study, the systematic evaluation of thermal properties was performed for CeO2–Gd2O3 (Gd2O3 = 0–15 wt%) samples. Gd2O3 doping into CeO2 reduced the grain size of CeO2–Gd2O3 solid solution and caused the expansion of the lattice parameter. The thermal conductivity of CeO2–Gd2O3 solid solutions decreased with increasing Gd2O3 content and decreased with temperature up to nearly 900 K, though the decreasing rates became smaller at a higher temperature. The values of the thermal conductivity were mostly attributed to phonon mean free path which decreased due to the Umklapp processes at high temperatures and reduced by phonon scattering due to Gd dopants and oxygen vacancies at low temperatures. The phonon scattering caused by grain boundaries, and chemical impurities can be neglected, and the isotope effect is considered to be small.

中文翻译：

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Ce1-yGdyO2-x固溶体的结构和热性能评价

在本研究中，对 CeO2–Gd2O3（Gd2O3 = 0–15 wt%）样品进行了热性能的系统评估。掺杂到 CeO2 中的 Gd2O3 减小了 CeO2-Gd2O3 固溶体的晶粒尺寸并引起晶格参数的扩展。CeO2–Gd2O3 固溶体的热导率随着 Gd2O3 含量的增加而降低，并随着温度升高至接近 900 K 而降低，但在较高温度下降低率变小。热导率的值主要归因于声子平均自由程，该声子平均自由程因高温下的 Umklapp 过程而降低，并因低温下 Gd 掺杂剂和氧空位引起的声子散射而降低。晶界和化学杂质引起的声子散射可以忽略不计，同位素效应被认为很小。