[12a-D221-1~9] 9.4 Thermoelectric conversion

△ [12a-D221-7] Enhancing thermoelectric properties of Mg₂Sn_1-xSb_x single crystals via introducing Mg vacancies

〇(DC)Wataru Saito¹, Kei Hayashi¹, Zhicheng Huang¹, Yuzuru Miyazaki¹ (1.Tohoku Univ.)

Keywords:Thermoelectric, Mg2Sn, point defect engineering

The Sb substituted polycrystalline Mg₂Sn_1-xSb_x exhibited a high PF value, however, the lattice and bipolar thermal conductivity (κ_L + κ_Bip) was relatively high. In this presentation, we prepared Mg₂Sn_1-xSb_x single crystals (x = 0, 0.01, 0.02) with introducing V_Mg and investigated these TE properties. From the single crystal structure refinement, V_Mg existed in the prepared Mg₂Sn_1-xSb_x single crystals. The prepared x = 0.02 single crystal exhibited lower κ_L + κ_Bip than the same Sb content polycrystal (reported in previous literature) at whole temperature, and the minimum κ_L + κ_Bip of 2.0 W/mK was realized at 650 K. Thus, these results suggested the point defect scattering increased by introducing V_Mg. In the Conference, the x dependence of TE properties is also presented.