Peltier cooling of superconducting electronics

The increase of the superconducting transition temperature in some of the cuprate superconductors to values higher than 130 K is generating strong interest in the exploration of Peltier cooling for the operation of superconducting electronics. In this case, we need materials with a sufficiently large figure of merit z down to temperatures near 100 K. We have performed measurements of the Seebeck coefficient, the thermal conductivity and the electric resistivity in the temperature range 80-300 K of Bi₂Te₃-based materials with admixtures of Sb and Se, and studied the influence of pulverization and sintering. The resulting z-values are reported. The influence of sintering on the microstructure of the samples has been studied by SEM