Transport properties of SnTe-Bi₂Te₃ alloys

Bismuth telluride based alloys have been a class of important thermoelectric materials widely used in cooling devices around room temperature. In this work, a series of polycrystalline samples of ternary compounds in the SnTe-Bi₂Te₃ system were prepared by rapid quenching of the melt followed by a sintering procedure of compacted pellets. The electrical conductivity and Seebeck coefficient of samples with various compositions were measured from room temperature up to about 600 K. The measured results show that the transport properties strongly vary with the composition and temperature. The microstructure in this system shows randomly oriented fine plate-shaped grains with multi-layered structure.