ホットプレスと常圧焼成の組み合わせにより作製したBi_0.4Sb_1.6Te_3.0焼結体の微構造および熱電特性

抄録

p-type Bi_0.4Sb_1.6Te_3.0 sintered materials were prepared by hot pressing and combination of pressureless sintering and hot pressing, and the effect of pressureless sintering on the microstructures and thermoelectric properties of the sintered materials were investigated. Samples prepared by hot pressing after pressureless sintering had the microstructures with grain growth and showed higher power factors in comparison with samples prepared by hot pressing and pressureless sintering after hot pressing. It is considered that the higher power factors attribute the increase in the mobility caused by increasing in the grain size due to pressureless sintering before hot pressing. The thermal conductivities also showed a little higher values due to the increases in both carrier and lattice thermal conductivities. Consequently, the sample prepared by hot pressing after pressureless sintering showed the highest figure of merit of Z = 3.69×10^-3 K^-1 for a sintering temperature of 803 K.