La0.4Ni0.2Co3.8Sb12 filled skutterudite compound was successfully prepared via the route of mechanical alloying and hot pressing (MA-HP). Single-phase filled skutterudite can be obtained when the mechanically alloyed powders is hot pressed for 2 h at a temperature higher than 550°C. Prolonging the hot pressing process, the electrical resistivity of the La0.4Ni0.2Co3.8Sb12 filled skutterudite decreases; Seebeck coefficient increases when the hot press duration is prolonged from 2 to 4 h, and no evident change was observed on further prolonging. A composite microstructure, which consists of some coral-like clusters and a nanocrystalline matrix with grain size about 50 nm in the La0.4Ni0.2Co3.8Sb12 filled skutterudite, was observed for the first time. The coral-like microstructure is thought to be the prime filled skutterudite phase produced directly by MA, while nanocrystalline matrix is the filled skutterudite phase formed during hot press.
No Supplementary Data
No Article Media
Document Type: Research Article
State Key Laboratory of Materials Processing and Die & Mould Technologies, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
Publication date: 2011-01-01