Thermoelectric power in disordered mixed crystals

In disordered mixed crystals the effect of alloy scattering is known to be of significant importance in comparison with that of lattice scattering in the consideration of electrical and thermal transport properties. In this work we consider the thermoelectric power in such isotropically disordered mixed crystals. We derive the energy current density operator for a combined electron and vibrating ions of the lattice system with the electron-lattice interaction term included. In this preliminary report, the relative importance of electrons and lattice vibrations to the thermoelectric power is discussed. The coherent potential approximation may be used to obtain the thermoelectric power of the disordered mixed crystal as function of the concentration. Our operator formulation is in coordinate space which besides containing previous formulations for metals and alloys as special cases, admits of the coherent-potential approximation methods to be applied as well.