Thermoelectric Properties of Bi_2Te_3 Alloy Prepared by Mechanical Alloying and Spark Plasma Sintering

摘要

The Bi_2Te_3 compound was synthesized by mechanical alloying (MA) of highly pure constituents of Bi and Te powders, and then was consolidated by spark plasma sintering (SPS) method. The MA-derived alloy formation was characterized by X-ray diffraction (XRD), and the microstructure change was investigated through scanning electron microscopy (SEM). The thermoelectric properties were measured using a Seebeck Coefficient/Electrical Resistance Measuring System. The influence of MA time on the thermoelectric properties of the SPS-sintered samples was investigated to find the optimal MA condition for the powder synthesis and thermoelectric properties. The obtained results showed that the sample with the MA time of 6 h exhibited the optimal electrical transport properties. The maximum power factor of over 2.0 × 10~(-3) W/m K~2 was obtained between 323 K and 423 K.