New synthesis of MnSi2 thin film and its thermoelectric properties

The authors report the formation of a new manganese silicide phase, MnSi2, using an intermixing method that involves evaporating a manganese thin film on a silicon substrate at a high temperature of 600 °C. The crystal structure of MnSi2 is tetragonal with lattice constants of a = 5.518 A and c = 17.449 A, identical to that of Mn4Si7. Analysis of the film using high-angle annular dark-field imaging confirmed that the composition ratio of Mn and Si was 1:2. The electric resistivity and Seebeck coefficient of the film were 2.08 × 10−3 Ω cm and 107.84 μV/K at 410 K, respectively, which resulted in a maximum power factor of 5.60 × 10−4 W/K2m.