SYNTHESIS OF Cu1.6Bi4.6S8 COMPOUND FOR THERMOELECTRIC APPLICATION

Abstract

In this work, Cu1.6Bi4.6S8 thermoelectric compound was synthesized using high energy milling and heat treatment. The starting mixture include Cu, Bi and S elemental powders at the stoichiometry ratio of the formula Cu1.6Bi4.6S8 were ball milled in a planetary ball mill and heat treated in an electric furnace. The results shown that after 10 hours of milling, a compound identified as Cu3.21Bi4.79S9 was formed. The 16h milled powder was heat-treated at 350, 400 and 450ºC for 1 hours at a heating rate of 8 ºC/minute, XRD of the annealed powder reveals that the Cu3.21Bi4.79S9 obtained fully transformed into Cu1.6Bi4.6S8 after being heat treated at 400ºC. Meanwhile, Bi2S3 was found in the powder being annealed at 350ºC. The 5h milled powder was also annealed at 400ºC for 1 hours at a heating rate of 2 and 8 ºC/minute, XRD analysis show that Cu1.6Bi4.6S8 was also formed in the heat-treated powder with the heating rate of 2 ºC/min.