Synthesis and thermoelectric properties of filled skutterudite by a solid reaction method

Abstract

The filled skutterudite compounds, MyFexCo4-xSb12 (x = 0-1.0, y = 0-0.15, M = Ce, La, Y), were prepared by a new solid state reaction method using Co, Fe, Sb, CeCl3·6H2O, LaCl3·6H2O and YCl3·6H2O powders, and their thermoelectric properties were investigated. MyFexCo4-xSb12 (x = O-1.0, y = 0-0.15, M = Ce, La, Y) compounds showed p-type conduction. The electrical conductivity (σ) increased with increasing Fe content. The Seebeck coefficient (α) increased with increasing Fe content for MFexCo4-xSb12, but decreased with increasing Fe content for FexCo4-xSb12. The Lattice thermal conductivity (κL) decreased significantly with the substitution of Fe for Co and the filling of M (M = Ce, La, Y) into the Sb icosahedral voids, while the carrier thermal conductivity (κcar) was not much affected by the Fe substitution and the M (Ce, La, Y) filling. The thermoelectric figure of merit was improved by the combination of Fe substitution and M (Ce, La, Y) filling.