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

The thermoelectric properties of Al-doped Mg2Si1−xSnx (x = 0.0–0.1) [Mg2Si1−xSnx: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 Mg2Si1−xSnx samples are n-type in the measured temperature range. By Al-doping, electron concentration is controlled up to 5.3 × 1019 cm−3 in the composition range 0.0 ≦ x ≦ 0.1. Al-doped Mg2Si0.9Sn0.1 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 Mg2Si0.9Sn0.1.