Thermoelectric behaviour of SmS and Sm0.84Gd0.16S at high pressures and temperatures

The 4f→ 5d electronic phase transition in SmS has been studied using thermoelectric power as a probe. The variation of thermopower with pressure in Sm_0.84Gd_0.16S and in the high pressure phase of SmS is anomalous, characterized by a rather large pressure coefficient. The temperature coefficient of thermopower in Sm_0.84Gd_0.16S is large and negative at low pressures leading to a change of sign at higher temperatures. The anomalies can be understood on the basis of the ICF model.