Thermoelectric properties of Al-doped Mg2Si1−Sn (x≦ 0.1)

Abstract The thermoelectric properties of Al-doped Mg 2 Si 1− x Sn x ( x = 0.0–0.1) [Mg 2 Si 1− x Sn x :Al = 1: y (0.00 ≦ y ≦ 0.02)] fabricated by spark plasma sintering have been characterized by Hall effect measurements at 300 K and by measurements of electrical resistivity ( ρ ), the Seebeck coefficient ( S ), and thermal conductivity ( κ ) between 300 and 900 K. Al-doped Mg 2 Si 1− x Sn x samples are n-type in the measured temperature range. By Al-doping, electron concentration is controlled up to 5.3 × 10 19 cm −3 in the composition range 0.0 ≦ x ≦ 0.1. Al-doped Mg 2 Si 0.9 Sn 0.1 shows a maximum value of the figure of merit ZT of 0.68 at 864 K, which is 6 times larger than that of nondoped Mg 2 Si 0.9 Sn 0.1 .