Unveiling the Correlation between the Crystalline Structure of M-Filled CoSb3(M = Y, K, Sr) Skutterudites and Their Thermoelectric Transport Properties
Unveiling the Correlation between the Crystalline Structure of M-Filled CoSb3(M = Y, K, Sr) Skutterudites and Their Thermoelectric Transport Properties
复制标题
DOI：
10.1002/adfm.202001651
复制
发表时间：
2020-09-01
影响因子：
19
通讯作者：
Alonso, Jose A.
中科院分区：
文献类型：
--
作者：
Gainza, Javier;Serrano-Sanchez, Federico;Alonso, Jose A.
基于CoSb(3)的角钨矿型化合物是一种很有前途的热电半导体材料。利用同步加速器x射线粉末衍射对不同M填充的CoSb3（M = Y， K, Sr, La, Ce, Yb）方毛石进行了详尽的结构表征，这些M原子具有非常不同的化学性质，可以从晶体化学的角度更好地理解填充的影响。这些分析的重点是化学和结构特征与某些家族填充- cosb (3) skutterites所显示的热电性能增强的相关性。这些主要是由Sb的位置参数决定的，得到的Oftedal图取决于填料的填充分数、离子状态和原子半径。再加上[Sb-4]环和[CoSb6]八面体在菱角矿结构中的畸变，这些结果与能带收敛概念及其对热电输运性质的影响有关。在这里，不同化学成分中观察到的结构变化与理解单个部分填充的n型方晶石的热电性能改善有关。
Skutterudite-type pnictides based on CoSb(3)are promising semiconductor materials for thermoelectric applications. An exhaustive structural characterization by synchrotron X-ray powder diffraction of different M-filled CoSb3(M = Y, K, Sr, La, Ce, Yb) skutterudites, with a panoply of M atoms with very different chemical nature, allows to better understand the effects of filling from a crystallo-chemical point of view. These analyses focus on the correlation of chemical and structural features with the enhanced thermoelectric properties displayed by certain families of filled-CoSb(3)skutterudites. These are mainly determined by Sb positional parameters, yielding Oftedal plots that depend on the filling fraction, ionic state, and atomic radius of the filler. Together with the distortion of [Sb-4] rings and [CoSb6] octahedra present in the skutterudite structure, these results are linked to the band-convergence concept and its influence on the thermoelectric transport properties. Here, the structural changes observed in the different chemical compositions are relevant to understand the improved thermoelectric performance of single partially filled n-type skutterudites.