Thermoelectric properties of hot-pressed skutterudite CoSb3

In the present work, skutterudite CoSb3 were fabricated by hot pressing at different sintering temperatures under vacuum and argon. For the prepared compacts, the phase, the microstructure, and the temperature dependent thermoelectric properties were characterized. The correlation of the materials factors: density, grain size, Sb content, with the thermoelectric variables: Seebeck coefficient, electrical conductivity, thermal conductivity, and dimensionless figure of merit (ZT), is presented. The achieved ZT values are also compared with those reported in the literature. The investigated samples show larger electrical conductivity due to existence of metallic Sb and smaller thermal conductivity because of fine-grained structure. A maximal ZT of 0.11 was achieved for the samples sintered at 853 K under vacuum and at 773 K under argon. A moderate improvement on ZT for pure CoSb3 is shown in the present work. (c) 2007 American Institute of Physics.