Synthesis and thermoelectric properties of Cd-filled CoSb3

Cd-filled CoSb3 samples have been synthesized by the high pressure method, and the temperature-dependent thermoelectric properties of CdxCo(4)Sb(12) have been investigated from 300 to 600 K. X-ray diffraction results show that near single-phase CoSb3 could be obtained by the high pressure method in a short time (20 min). The lattice constant increases with the increase in the Cd content. The power factor is improved and the thermal conductivity is depressed drastically by filling CoSb3 with Cd. The maximum figure of merit reaches 0.54 at 600 K for the sample of Cd0.38Co4Sb12, which is about four times higher than that of unfilled CoSb3.