Phase transitions of p-type (Pb,Sn,Ge)Te-based alloys for thermoelectric applications

p-type (Pb,Sn,Ge)Te-based alloys for thermoelectric applications were prepared using Bridgman technique. Second-order, rhombohedral to cubic phase transitions are involved, as evaluated from anomalies in the temperature dependence values of Seebeck coefficient, electrical conductivity, heat flow and the elongation, in the vicinity of the phase transition temperature, Tc. The correlation between these anomalies in both the electronic and thermodynamic properties was interpreted by means of the relationship of Fermi energy to the chemical potential (or to the molar Gibbs free energy).