Improvement of thermoelectricity of the oxide and electronic structures

S. Sugihara, M. Yamamoto, M. Katayose

We investigated thermoelectric materials (TE) such as iron disilicide and the oxides with different structures such as ZnO and magnetic oxide in terms of experimental method and computer simulation. The TE property of FeSi₂ was improved by adding oxide such as Gd₂O₃ or LaSrMnO₃. The roles of oxide are regarded that in the first case, the oxide itself works as TE which has usually lower thermal conductivity and higher Seebeck coefficient, and secondly the oxide can be employed as an additive material to the conventional TE. We also studied electronic structures of element substituted-FeSi₂ (FeMSi₂ , M=metal) as well as ZnO and magnetic oxide. Energy gap taking into account of impurity level is important will be discussed for estimation of Seebeck coefficient in the element substituted -FeSi₂ and -ZnO. Furthermore, spin configuration will also discussed for the electronic structures of magnetic material.