Fe掺杂CoSb_3化合物的热电性能及电子结构研究  

Thermoelectric Properties and Electronic Structure of Fe-doped CoSb_3 Compounds

作　　者：朱云广[1] 沈鸿烈[1] 陈海力[1] 鲁林峰[1] 管浩[1] 

机构地区：[1]南京航空航天大学材料科学与技术学院,南京210016

出　　处：《人工晶体学报》2011年第2期424-429,共6页Journal of Synthetic Crystals

基　　金：江苏省科技支撑计划项目(BE2008020)

摘　　要：采用机械合金化结合冷等静压的方法制备了Co4-xFexSb12化合物,探讨了Fe掺杂对化合物热电性能的影响;利用基于密度泛函理论赝势平面波的方法对Fe掺杂前后的CoSb3的电子结构进行了计算。结果表明：在Co4-xFexSb12化合物中Fe的固溶极限x在0.3-0.5之间;CoSb3的费米面位于导带和价带之间,其电阻率随温度的升高而降低,为非简并半导体;Fe掺杂后费米面进入价带,使其成为p型简并半导体,电阻率较掺杂前大大降低并随温度的升高而增加;本实验条件下,Co3.7Fe0.3Sb12化合物的功率因子在600 K时出现1406.31μW/m.K2的最高值,是未掺杂试样的功率因子最高值的7.4倍。Co4-xFexSb12 compounds were prepared by mechanical alloying combined with cold isostatic pressing methods.The effect of Fe doping on the thermoelectric properties was studied.The electronic structure of Fe-doped and undoped compounds was calculated using the first principle plane-wave pseudo-potential based on the density function theory.The experimental and calculated results show that the value of solution limit x of Fe was between 0.3 and 0.5.Fermi surface of CoSb3 locates between conduction band and valence band,indicating that CoSb3 is a semiconductor and its electrical resistivity decreases as the temperature increasing.The Fermi surface of Fe-doped compound moves to the valence band and its electrical resistivity increases as the temperature increasing,exhibiting p-type degenerated semiconductor character.Under the condition of experiment,the maximum value 1406.31 μW/m·K2 of power factor for Co3.7Fe0.3Sb12 is obtained at 600 K,which is about 7.4 times as much as that of CoSb3.

关 键 词：Co4-xFexSb12 冷等静压 热电性能 电子结构 能带结构 态密度 

分 类 号：TN304.2[电子电信—物理电子学]