The CPA Calculation of the Thermoelectric Power of a Binary Alloy with Off-Diagonal Disorder

Abstract

The thermoelectric power of a binary alloy with off-diagonal disorder as well as diagonal one is calculated by means of the extended coherent potential approximation due to Shiba and others. It is shown that the off-diagonal disorder has a very striking effect on the thermoelectric power as well as on the conductivity. In the calculation the “underturbed” band is treated accurately for a simple cubic tight-binding model. Our improved treatment of the van Hove singularities of the “unperturbed” band reveals that the effect of the singularities on the transport coefficient is more pronounced than that calculated by Levin et al.