Thermoelectric transport and microstructural study of Cu doped Mg2Si0.4Sn0.6

The Mg2X (X = Si and Sn) based alloys which are composed of abundant, non-toxic and inexpensive elements are promising mid-temperature thermoelectric (TE) materials. Herein, we report synthesis of Mg2Si0.4Sn0.6 by high energy ball milling followed by hot pressing for thermoelectric application. The use of Cu as a dopant, appears to provide p-type conductivity but experimentally, the system has been found to generate n-type conduction. The XRD investigations revealed successful attainment of a near to single phase alloy with only minute presence of elemental Si. Electrical conductivity of the order of 104 S/m and charge carrier concentration of the order of 1019 cm−3 have been obtained through ZEM and Hall coefficient measuring equipment respectively. LFA provides thermal conductivity in the range of 4.4 – 3.0 W/mK. In addition to the thermoelectric measurements, the elemental mapping of the hot-pressed sample has been carefully explored.