Preparation and thermoelectric properties of ternary superionic conductor CuCrS2

Transition metal chalcogenide CuCrS2 powder was synthesized by mechanical alloying (MA) and then consolidated by spark plasma sintering (SPS) technique at 673–1073 K. The phase structure, microstructure and thermoelectric properties of samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and Seebeck coefficient/electrical conductivity measuring system, respectively. All the bulks indicated a single phase CuCrS2, while the high relative density over 90% were attained for the samples sintered at 873–1073 K. The electrical conductivity of bulk samples displayed a typical characteristic of semiconductor. With increasing measuring temperature, the conductive behaviour of bulk samples sintered over 973 K showed a semiconductor transformation from n-type to p-type due to the changes of main carrier type. The sample obtained by applying SPS at 873 K got the highest power factor 83.2 μW m−1 K−2, and the largest ZT value 0.11 at 673 K.