Recrystallization and electric properties of low-temperature thermoelectric materials extruded from ceramic blanks

The effect of annealing regimes and the recrystallization mechanism on the structure and properties of half-cells extruded from ceramic blanks with different sizes of the initial powder particles was analyzed. The experiment was conducted on n type alloys of the composition 96 mol.% Bi2Te3 - 4 mol.% Bi2Se3 alloyed with CdCl2, and p type alloys of the composition 74 mol.% Sb2Te3 -24 mol.% Bi2Te3 alloyed with Pb. The material of the central part of the rods recrystallizes in according to two mechanisms - true recrystallization and ''in situ'' recrystallization. The dependence of the electrical properties of the material on the annealing temperature is explained. It was established that during the recrystallization of thermoelectric materials their electrophysical properties depend on the powder grain size of the initial blank and on the heat treatment conditions