The thermoelectric properties of InxM0.2Co4Sb12 (M=Ba and Pb) double-filled skutterudites

Skutterudite compounds InxM0.2Co4Sb12 (M=Ba and Pb) with bcc crystal structure have been prepared by high pressure and high temperature (HPHT) method. Through this method, the processing time can be reduced from a few days to half an hour. Remarkably the combination of In and Ba was much more effective in reducing lattice thermal conductivity κL than In and Pb. The structure of InxM0.2Co4Sb12 skutterudites was evaluated by means of x-ray diffraction, and Seebeck coefficient, electrical resistivity, power factor and thermal conductivity of InxM0.2Co4Sb12 were all presented in the temperature range of 314.9–673 K. The transport properties measured on the synthesized samples have been compared with each other. The figures of merit, ZT, of samples all increased with the increasing temperature. Among all the samples, In0.5Ba0.2Co4Sb12 showed the highest power factor of 30.3 μW cm−1 K−2 at 643.5 K, the lowest lattice thermal conductivity 1.128 W m−1 K−1 at 643.5 K and the maximum ZT value 0.80 at 673 K.