Thermoelectric Properties of Co-Doped TiS2

The thermoelectric properties of cobalt-doped compounds Co (x) Ti1-x S-2 (0 a parts per thousand currency sign x a parts per thousand currency sign 0.3) prepared by solid-state reaction were investigated from 5 K to 310 K. It was found that the electric resistivity rho and absolute thermopower |S| for all the doped compounds decreased significantly with increasing Co content over the whole temperature range investigated. The increased lattice thermal conductivity of the doped compounds would imply enhancement of the acoustic velocity. Moreover, the ZT value of the doped compounds was improved over the whole temperature range investigated, and specifically reached 0.03 at 310 K for Co0.3Ti0.7S2, being about 66% larger than that of TiS2.