Thermoelectric properties of the CoSi1−xGex alloys

Abstract

The effects of Ge partial substitution for Si on the thermoelectric properties of CoSi1−xGex alloys were investigated by means of thermal and electrical transport measurements. Electrical resistivity (ρ), Seebeck coefficient (S), and thermal conductivity (κ) measurements were performed on a series of CoSi1−xGex alloys with x varying from 0 to 0.15. A substantial decrease in electrical resistivity and lattice thermal conductivity was noticed with increasing substitution level, whereas the Seebeck coefficient shows a weak variation with respect to Ge concentration. The thermoelectric efficiency was found to be enhanced by an order of magnitude in CoSi with Ge substitution. These observations were interpreted on the basis of the changes in the electronic band structure induced by Ge substitution.