Rapid preparation of CeFe4Sb12 skutterudite by melt spinning: rich nanostructures and high thermoelectric performance

Abstract

In this work, we adopt a non-equilibrium melt spinning technique combined with a subsequent spark plasma sintering technique to successfully synthesize a p-type nanostructured CeFe₄Sb₁₂ skutterudite compound with high homogeneity in less than 24 hours. Microstructures of the melt-spun ribbons and the sintered bulk material are systematically investigated. The evolution of multiple-phase melt-spun ribbons into a single-phase skutterudite compound during the heating process is also carefully examined. Greatly refined matrix grains (300–500 nm) and numerous FeSb₂ nanodots with sizes below 50 nm are evenly distributed inside the grains, and together contribute to the experimentally observed low lattice thermal conductivity of the sintered bulk material. Both absolute and average ZT values of this melt-spun skutterudite are about 10% higher than in the material of the same composition prepared by traditional melting and long-term annealing. The markedly shortened preparation time coupled with the enhanced thermoelectric performance should make this synthesis process of interest for commercial applications.