Synthesis of Nano-skutterudite Compound Powder by Cross-coprecipitation Method

Nano-skutterudite compound CoSb3 powder was synthesized by a cross-coprecipitation method. The starting reagents were CoCl2·6H2O, SbCl3 and both precipitators of sodiumhydroxide and ammonia. After dispersed, filtrated, washed and dried, a precursor composed of antimony oxide and cobalthydrate was obtained at room temperature and between pH=5-10. The effects of reduction atmosphere, temperature, remaining time and molar ratio of Co/Sb on phase composition and the particle size of reducing product were investigated. Powders obtained at the different processing steps were characterized by TG-DSC, XRD, SEM and EDX techniques. The results indicated that the CoSb3 compound powders with homogeneous particle size about 100nm were obtained through reducation processing, remaining for 3h under 500℃ while flowing pure hydrogen and moral ratio Sb/Co=3.15.