Thermoelectric properties of $n$-Type Mg$_{2}$Si–Mg$_{2}$Sn solid solutions with different grain sizes

Influence of the grain sizes on thermoelectric parameters of pressurized solid solutions of the composition Mg$_{2}$Si$_{0.8}$Sn$_{0.2}$ was studied. The Seebeck coefficient, electric conductivity, thermal conductivity, and Hall coefficient were determined. Decreasing the grain size to the nanoscale was found to decrease the mobility at low temperatures and resulted in a peculiar temperature dependence of the electric conductivity, but did not lead to a decrease in the thermo EMF. It was found that the grain size had no effect on the thermoelectric efficiency of the investigated solid solution in the operating temperature range.