Skutterudite化合物Fe_xCo_(4-x)Sb_(12)的固相反应合成及热电特性

SOLID STAE REACTION SYNTHESIS OF SKUTTERUDITE COMPOUNDS Fe_xCo\_(4-x)Sb_(12)AND THERMOELECTRIC PROPERTIES

用固相反应法在 90 0— 10 0 0K温度范围和x =0— 1 0的组成范围内合成了单相Co基Skutterudite化合物FexCo4 -xSb12 ,并对化合物的结构和热电特性影响进行了研究 .结果表明 :化合物的晶格常数随Fe置换量的增加线性增加 ,载流子浓度和电导率随Fe置换量的增加而增加 ,Seebeck系数随Fe置换量的增加而减少 ,Seebeck系数的峰值温度随Fe置换量的增加向高温方向移动 ,晶格热导率由于Fe的置换而大幅度下降 ,并随Fe的置换量的增加而进一步降低 .对于Co基Skutterudite化合物FexCo4 -xSb12 ,得到的最大热电性能指数ZT大约为 0 5 .

Skutterudite compounds Fe\- x Co\-\{4- x Sb\-\{12\} were synthesized by solid state reaction using high\|purity powders of Co,Fe,and Sb as starting materials.Fe\- x Co\-\{4- x Sb\-\{12\}( x =0—1 0) compounds were obtained at 900—1000?K.The lattice constant of Fe\- x Co\-\{4- x \}Sb\-\{12\} increased with increasing substitution of Fe for Co sites.Carrier concentration and electrical conductivity increased with increasing Fe content.Seebeck coefficient decreased and T opt of Seebeck coefficient shifted to higher temperature with increasing Fe content.Lattice conductivity was reduced significantly by substitution of Fe for Co sites.The maximum ZT value of 0\^5 was obtained for Fe\-\{0.92\}Co\-\{3.08\}Sb\-\{12\} at 750K.