制备方法对NixCo4-xSb12化合物结构和热电性能的影响

Effects of Preparation Technology on Structure and Thermoelectric Properties of NixCo4.xSb12 Compounds

摘要:

分别采用固相反应-放电等离子体烧结法（SR-SPS）和球磨-放电等离子体烧结法（MG-SPS）两种方法，系统研究了制备工艺对NixCo4-xSb12（x=0.1-0.5）化合物结构和热电性能的影响规律。研究表明：两种制备工艺对于化合物的物相结构及赛贝克系数的影响差异不大，但在Ni含量较低的情况下，SR-SPS的制备工艺增大了材料的电阻率和晶粒尺寸，使材料热导率增加，从而导致热电性能的降低；与SR-SPS相比，MG-SPS方法不但简便快捷，降低能耗，更有利于材料热电性能的提高；本实验范围内，采用MG-SPS方法制备的Ni0.2Co3．8Sb12烧结体在温度T=-773K时，其无量纲热电性能指数ZT达到了0．6。

Abstract:

Effects of preparation technology on structure and thermoelectric properties of NixCo4-xSb12(x=0.1~0.5)were investigated separately by solid reaction-spark plasma sintering(SR-SPS)and mechanical milling-spark plasma sintering(MG-SPS)method.The two methods had little effect on phase structure and Seebeck coefficient,but SR-SPS technology augments electrical resistivity and the grain size of products when the content of Ni was as low as 0.1,and hence increase the thermal conductivity and decrease the thermoelectric properties.Compared with SR-SPS,MG-SPS method not only is simple and convenient in preparation,but also is propitious to the improvement the thermoelectric properties.In our experimental range,the Ni0.2Co3.8Sb12 bulk sintered by MG-SPS shows maximum ZT value of 0.6 at about 773 K.