p型TaFeSb基Half-Heusler合金的热电性能优化

Optimization of Thermoelectric Properties of p-type Half-Heusler Alloy TaFeSb

通过高能球磨和直流快速热压相结合的工艺制备TaFeSb基half-Heusler合金,对其进行热电性能测试,分析Ta位Ti掺杂对TaFeSb合金热电性能的影响。结果表明:TaFeSb是一种p型热电材料;Ti掺杂使得样品的热导率下降,电导率提高,塞贝克系数随Ti掺杂浓度的增加略有降低;Ti掺杂后样品的功率因子显著提高,ZT值明显增加;在973 K时,Ta_(0.80)Ti_(0.20)FeSb样品的峰值ZT达到0.8。

TaFeSb-based half-Heusler alloys were prepared by high-energy ball milling combined with DC rapid hot pressing.It is proved that TaFeSb is a p-type thermoelectric material.In this paper,the effects of Ti doping in Ta site on the thermoelectric properties of TaFeSb were investigated.The experimental results show that Ti doping decreases the thermal conductivity and increases the electrical conductivity of the samples,and the Seebeck coefficient decreases slightly with the increasing content of Ti.Consequently,the power factor shows a significant improvement after Ti doping,and the ZT value of Ta_(1-x)Ti_(x)FeSb alloy has been obviously increased.Finally,a maxmium ZT value of 0.8 has been achieved for Ta_(0.80)Ti_(0.20)FeSb sample at 973 K.