Interdiffusion Studies in the Co-Sb System

Abstract

CoSb based compounds have gained much importance in the fields of thermoelectric devices. In this work, we have conducted the solid–state conventional bulk diffusion couple experiments. To study the phase evolutions, Co/Sb diffusion couples are annealed at 450–550 °C. The interdiffusion zone is analysed using field emission gun equipped scanning electron microscope and the composition measurements are done in electron probe micro−analyser to confirm the growth of various product phases. The marker experiment indicates that the CoSb3 phase grows mainly by diffusion of Sb in the binary Co–Sb system. Growth of the CoSb3 phase is discussed based on assessment correlating the difference in mobilities of species with the high homologous temperature, crystal structure of the phase, and the concept of sublattice diffusion mechanism in line compounds.