Te掺杂方钴矿CoSb3的溶剂热合成及电学性能

以CoCl₂, SbCl₃和Te粉为原料, NaBH₄为还原剂, 用溶剂热方法合成了Te掺杂方钴矿CoSb_3-xTe_x(x=0, 0.05, 0.1, 0.2, 0.4)纳米粉末. 研究发现, Te含量较高的样品(x≥0.2)有明显的CoTe₂等杂相存在. CoSb_3-xTe_x合成粉末的粒径大小在40nm左右, 热压后晶粒发生长大, 平均晶粒尺寸约为300nm. 电学性能测试表明Te掺杂方钴矿CoSb_3-xTe_x的导电类型为n型, Seebeck系数的绝对值随着Te含量的增加而变小, 电导率随着Te含量的增加而增大. 在测试温度范围内, CoSb_2.8Te_0.2 具有最高的功率因子, 在773K温度下达到2.3×10³W·m^-1·K^-2.

Solvothermal Synthesis and Electrical Transport Properties of Te-doped CoSb3 Skutterudites

Nanosized Te-doped skutterudites CoSb_3-xTe_{x ⁽}x=0, 0.05, 0.1, 0.2, 0.4) were prepared by a solvothermal method using CoCl₂, SbCl₃ and pure telluride powder as precursors and NaBH₄ as reductant. It is found that trace of other impurity phases such as CoTe₂ are coexisted for x≥0.2. The size of synthesized CoSb_3-xTe_x powders is about 40nm, and the grains are grown up to an average size of about 300nm after hot-pressing. Transport properties measurements indicate that the Te-doped CoSb_3-xTe_x have n-type conduction. As the Te fraction increases, the values of electrical conductivity increase, while the absolute Seebeck coefficient values decrease. A maximum power factor of 2.3×10^-3W·m^-1·K^-2 is obtained at 773K for CoSb_2.8Te_0.2.