Mg2Si compounds were synthesized by a solid state reaction, and the silicide transformation was analyzed using X-ray diffraction. Electronic transport properties (Hall coefficient, carrier concentration and mobility) and thermoelectric properties (Seebeck coefficient, electrical conductivity, thermal conductivity and figure-of-merit) were examined. Mg2Si was successfully synthesized by a solid state reaction at 673-773 K for 6-12 h, and fully consolidated by hot pressing at 1073 K for 2 h. Intrinsic Mg2Si showed n-type conduction indicating that the electrical conduction is mainly due to electrons. The absolute value of the Seebeck coefficient decreased and the electrical conductivity increased with an increase in the temperature due to intrinsic conduction at high temperatures. The thermal conductivity decreased with an increase in the temperature, and the lattice contribution was dominant. The thermoelectric figure-of-merit of intrinsic Mg2Si was low and it should be improved by doping.
Keywords: Thermoelectric, Mg2Si, Solid state reaction, Hot pressing.