Thermoelectric properties of Bi2Te3 sintered body fabricated by mechanical grinding process

摘要

The powder metallurgical fabrication of Bi2Te3thermoelectric materials using mechanical grinding process hasbeen studied with specific interest to control the microstructureand increase the figure of merit. The figure of merit of sinteredbodies of milled Bi2Te3 powder decreased with increasing millingtime, mainly due to the increase of the electrical resistivity withmilling time. It has been known that microstructure refinement bythe simple milling process was not effective to improve thethermoelectric properties of Bi2Te3 thermoelectric materials.Bi2Te3 sintered bodies with addition of nano size ZrO2 particlesfrom lvol.% to 4vol.% showed higher figure of merit than thatwithout addition of nano size ZrO2 particles. Especially, figure ofmerit of Bi2Te3 sintered bodies with addition of lvol.% ZrO2increased 1.6 times compared to the value of the specimen withoutaddition of ZrO2. Addition of nano size second particles tothermoelectric materials by mechanical grinding process seemed tobe useful method to increase figure of merit.