Correlations between Structural and Electronic Properties in the Filled Skutterudite Sm_<i>y</i>(Fe_<i>x</i>Ni_1–<i>x</i>)₄Sb₁₂

A structural study of the filled skutterudite Smy(FexNi1–x)4Sb12 was performed by means of X-ray powder diffraction and μ-Raman spectroscopy with the aim to unveil the correlations between structural and electronic properties of this material and to favor the improvement of its thermoelectric performance. Samples were prepared by direct reaction of the elements at 1223 K, followed by quenching and subsequent sintering at 873 K; microstructure and composition of the obtained products were determined by SEM-EDS. The position of the boundary separating regions that obey hole- and electron-based conduction mechanisms was found by X-ray diffraction at x ≈ 0.63 and y ≈ 0.30, confirmed by measurements of room-temperature Seebeck coefficient, and discussed on the basis of crystallographic data. The presence of a discontinuity is observed in several structural and spectroscopic parameters at the p/n crossover; it is interpreted as associated with the change in the conduction mechanism. The role of the rare earth filling fraction in driving the structural response of the material is investigated too. The advantage of using X-ray diffraction and μ-Raman spectroscopy as aids in the study of electronic properties of this material is highlighted, as well as the complementarity of the two techniques.本研究针对填充式方钴矿（filled skutterudite）Sm_y(Fe_xNi_1–x)₄Sb₁₂开展结构研究，采用X射线粉末衍射（X-ray powder diffraction）与微拉曼（μ-Raman）光谱法，旨在阐明该材料结构与电子性质间的关联，并推动其热电性能的优化。样品通过单质元素在1223 K下直接反应制备，随后经淬火处理，并于873 K进行后续烧结；所得产物的微观结构与组成通过扫描电镜-能谱联用（SEM-EDS）进行表征。本研究通过X射线衍射确定了空穴导电与电子导电区域的分界位置，对应x≈0.63、y≈0.30，该结果经室温塞贝克（Seebeck）系数测试验证，并基于晶体学数据展开讨论。在p/n型导电转变（p/n crossover）处，多项结构与光谱参数均出现不连续现象，该现象被归因于导电机制的转变。本研究同时探究了稀土填充占比对材料结构响应的调控作用，并强调了X射线粉末衍射与微拉曼光谱法在该材料电子性质研究中的辅助价值，以及两种技术间的互补性。