Structure of thermoelectric material CoSb3 formed by reactive diffusion

Abstract

Thermoelectric material, CoSb3, has been formed in solid Co/solid Sb, solid Co/liquid Sb and solid Co/vapor Sb reactive diffusion couples in the temperature range between 723 K and 1123 K. The solid Co/vapor Sb diffusion couples were annealed in a furnace having two homogeneity temperature zones keeping Co side and Sb side temperatures independently. CoSb3 phase formed in these Sb diffusion couples showed various structures such as granular grains, large size polygonal grains with sharp edge and a flat diffusion layer with many small voids or with Sb phase depending on the kind of diffusion couples and temperature. The formation kinetics of such structures and growth of CoSb3 have been studied and discussed.