Effects of a precipitation treatment on the thermoelectric properties in a CoSi thermoelectric material are investigated by scanning and transmission electron microscopy. The Seebeck coefficient and electrical conductivity are explained based on electron-phonon scattering by considering relaxation time approximation and its electronical structure in the framework of the Boltzmann transport equation in the as-sintered (AS) sample fabricated by spark plasma sintering. A precipitation treatment at 1073 K for 30 min is applied to the AS sample. The high Seebeck coefficient and electrical conductivity are obtained, while low thermal conductivity is achieved by dispersing metallic Co₂Si phases and insulating amorphous SiO₂ nanoparticles in addition to small grain size of ≈ 3 µm due to enhancement in phonon scattering. The dispersion of the amorphous SiO₂ is also beneficial in reducing the matrix grain size by the Zener drag.

通过扫描和透射电子显微镜研究了沉淀处理对 CoSi 热电材料热电性能的影响。塞贝克系数和电导率基于电子-声子散射进行解释，通过考虑弛豫时间近似及其在玻尔兹曼传输方程框架中的电子结构，在放电等离子体烧结制造的烧结 (AS) 样品中。在 1073 K 下对 AS 样品进行 30 分钟的沉淀处理。获得高塞贝克系数和电导率，同时通过分散金属 Co ₂ Si 相和绝缘非晶 SiO ₂实现低热导率由于声子散射的增强，除了 ≈ 3 µm 的小晶粒尺寸外，纳米粒子还可以。无定形SiO ₂的分散也有利于通过齐纳阻力减小基体晶粒尺寸。