The great improvement effect of pores on ZT in Co1-xNixSb3 system

In this paper, the Co1-xNixSb3+y system (x= 0.1, 0.2; y= 0, 0.05) has been prepared by direct current induced hot press and annealing. Pores were made by annealing pressed Co1-xNixSb3.05 pellets into Co1-xNixSb3 pellets during annealing. It was found that from room temperature to 500 degrees C, the pores with diameter larger than 1 mu m has significantly increased the Seebeck coefficient, considerably decreased the thermal conductivity, almost maintained the electrical conductivity constant, and therefore markedly improved the dimensionless figure of merit (ZT) of Co1-xNixSb3 system. By comparing the samples, we conclude that inducing pores into skutterudites is an effective route to greatly improve the ZT. (C) 2008 American Institute of Physics.