The exploration for synthesizing CoSb3 powder by mechanical alloying

In order to explore new technologies to synthesize the CoSb3 type thermoelectric materials, the basic technologies of preparing CoSb3 powder by mechanical alloying were investigated. The phase transformations and crystal size of Co-3Sb powder were analyzed by X-ray diffraction (XRD). The shape and grain size of CoSb3 powder were observed by scanning electron microscope (SEM) and transmission electron microscope (TEM). The results show that the single phase CoSb3 powder with 20-35nm nanocrystalline was prepared successfully by milling for 5h under a ball to powder ratio of 20:1 and a working voltage of 110V for the high-energy mill. It is considered that CoSb3 is a metastable phase in long time high-energy milling, as it tends to decompose.