Effect of current on the microstructure and performance of (Bi_2Te_3)_(0.2)(Sb_2Te_3)_(0.8) thermoelectric material via field activated and pressure assisted sintering*

摘要

(Bi_2Te_3/_(0.2)(Sb_2Te_3/_(0.8) thermoelectric material was sintered via a field activated and pressure assisted sintering (FAPAS) process. By applying different current intensity (0, 60, 320 A/cm~2/ in the sintering process, the effects of electric current on the microstructure and thermoelectric performance were investigated. This demonstrated that the application of electric current in the sintering process could significantly improve the uniformity and density of (Bi_2Te_3/_(0.2)(Sb_2Te_3/_(0.8) samples. When the current intensity was raised to 320 A/cm~2, the preferred orientation of grains was observed. Moreover, positive effects on the thermoelectric performance of applying electric current in the sintering process were also confirmed. An increase of 0.02 and 0.11 in the maximum figure of merit ZT value could be acquired by applying current of 60 and 320 A/cm~2, respectively.