Thermoelectric properties of Au-substituted Si-based clathrates, Ba 8AuGa 13Si 32 and Ba 6A 2AuGa x Si 45-x (A = Sr, Eu, x = 13, 14), were experimentally and theoretically investigated. The polycrystalline samples of the Au-substituted Si-based clathrates were prepared by using the spark plasma sintering technique. The electronic structure of Ba 6A 2AuGa 13Si 32 was theoretically calculated by ab initio calculations, and the thermoelectric properties of Ba 6A 2AuGa x Si 45-x were estimated through the calculated electronic structure. The effective mass of Ba 6A 2AuGa x Si 45-x was experimentally estimated to be greater than that of Ba 8AuGa 13Si 32. Experimentally observed electronic properties agree with the calculations for Ba 6A 2AuGa x Si 45-x. The maximum ZT value of Ba 6Sr 2AuGa 14Ge 31 is about 0.5 at 850 K. The calculated thermoelectric properties agree very well with the experimental results in the range from room temperature to 900 K.
All Science Journal Classification (ASJC) codes