Thermoelectric properties of NdGdS3 prepared by reaction of oxides with CS2

The rare-earth sulfide NdGdS₃ with Th₃P₄-type structure was prepared by heating a mixture of Nd₂O₃ and Gd₂O₃ in a stream of CS₃/Ar at 1273 K, followed by sintering at 1873 K. In order to evaluate the potential for thermoelectric applications, the electrical resistivity and the Seebeck coefficient were measured over the temperature range of 300 to 1000 K. The Seebeck coefficient is negative over the whole temperature range measured. The electrical resistivity and the magnitude of Seebeck coefficient increase linearly with increasing temperature. The thermoelectric power factor also increases with increasing temperature to a maximum value of 180 muW/K²middotm at 923 K