Response of vibrational properties and thermal conductivity of perovskites to pressure
Response of vibrational properties and thermal conductivity of perovskites to pressure
复制标题
钙钛矿的振动特性和热导率对压力的响应
DOI：
10.1016/j.mtphys.2023.101010
复制
发表时间：
2023
影响因子：
11.5
通讯作者：
Li, Chen
中科院分区：
文献类型：
--
作者：
Hou, Songrui;Wilson, Richard B.;Li, Chen
我们研究了SrTiO 3 和KTaO 3 的振动特性和热导率Λ 对加压的响应。我们的目标是增进对钙钛矿晶体结构、振动动力学和导热性之间关系的理解。我们通过时域热反射测量了 SrTiO 3 和 KTaO 3 的热导率高达 28 GPa。我们还对 SrTiO 3 和 KTaO 3 进行拉曼散射和受激布里渊散射测量，以表征振动动力学随压力的变化。 SrTiO 3 的热导率在压力下增加的斜率与其他钙钛矿的热导率相当，其热导率是随压力测量的。或者，KTaO 3 的热导率比具有类似晶体结构的其他材料具有更强的压力依赖性。我们将压力引起的拉曼和布里渊光谱变化与压力引起的热导率变化相关联。我们表明，压力引起的声子寿命变化主导着热导率的压力依赖性。这项研究提供了为什么 Λ 取决于压力的基准知识，并提高了对结构/热性能关系的理解。
We study the response of SrTiO 3 and KTaO 3's vibrational properties and thermal conductivity Λ to pressurization. Our goal is to improve the understanding of the relationship between crystal structure, vibrational dynamics, and thermal conductivity in perovskites. We measure the thermal conductivity of SrTiO 3 and KTaO 3 up to 28 GPa by time-domain thermoreflectance. We also perform Raman scattering and stimulated Brillouin scattering measurements of SrTiO 3 and KTaO 3 to characterize changes in vibrational dynamics with pressure. The thermal conductivity of SrTiO 3 increases under pressure with a slope comparable to that of other perovskites whose thermal conductivity has been measured versus pressure. Alternatively, the thermal conductivity of KTaO 3 has a stronger pressure dependence than that of other materials with similar crystal structure. We correlate pressure-induced changes in Raman and Brillouin spectra with pressure-induced changes in thermal conductivity. We show that pressure-induced changes in phonon lifetimes dominate the pressure dependence of thermal conductivity. This study provides benchmark knowledge of why Λ depends on pressure and improves understanding of structure/thermal-property relationships.