[16p-D411-1~13] 9.4 Thermoelectric conversion

▲ [16p-D411-11] Thermoelectric properties of bulk Ni-doped β-FeSi₂

〇Sopheap Sam¹, Soma Odagawa¹, Hiroshi Nakatsugawa¹, Yoichi Okamoto² (1.Yokohama National Univ., 2.National Defense Academy)

Keywords:Thermoelectric properties, Silicides, ZT value

In this study, we investigate the effect of Ni doping on the structural, electrical, and thermoelectric properties of β-FeSi₂ prepared by the conventional arc-melting technique. The result shows that the electrical resistivity can be effectively decreased with x due to the increase in carrier density. The absolute Seebeck coefficient of all Ni-doped samples is higher and more stable than that of non-doped ones due to the reduction in bipolar effect; however, it becomes decreasing as x increases due to the high carrier density and the increase in metallic ε-phase. The solid solution limit of Ni into the β-phase can be obtained at below x = 0.01. As a result, the highest power factor is obtained in x = 0.001 sample, leading to the improved ZT value of 0.019 at 600 K.