Solution Growth and Thermoelectric Properties of Single-Phase MnSi1.75−x

Abstract

We have investigated the crystal growth of single-phase MnSi1.75−x by a temperature gradient solution growth (TGSG) method using Ga and Sn as solvents and MnSi1.7 alloy as the solute, and measured the thermoelectric properties of the resulting crystals. Single-phase Mn11Si19 and Mn4Si7 crystals were grown successfully using Ga and Sn as solvents, respectively. The typical size of a grown ingot of Mn11Si19 was 2 mm to 4 mm in thickness and 12 mm in diameter, whereas Mn4Si7 had polyhedral shape with dimensions in the range of several millimeters. The single-phase Mn11Si19 has good electrical conduction (ρ = 0.89 × 10−3 Ω cm to 1.09 × 10−3 Ω cm) compared with melt-grown multiphase higher-manganese silicide (HMS) crystals. The Seebeck coefficient, power factor, and thermal conductivity were 77 μV K−1 to 85 μV K−1, 6.7 μW cm−1 K−2 to 7.2 μW cm−1 K−2, and 0.032 W cm−1 K−1, respectively, at 300 K.