The thermal and thermoelectric properties of sintered germanium-silicon alloys

The thermal and electrical resistivity and Seebeck coefficient of heavily doped, pressure-sintered germanium-silicon alloy specimens have been measured in the temperature range 300-1200K. The thermal resistivity was considerably in excess of that for corresponding crystalline samples at temperatures below that of the thermal resistivity maximum; the temperature of this maximum was, however, about 75K below that found in crystalline samples. It proved possible to explain the data below the maximum by a Callaway-type thermal conductivity calculation including both free-carrier and boundary scattering of phonons. The boundary scattering mean free path was smaller than might have been expected from the grain size.