Impurity enhancement effects in the frame of the five-frequency model

Abstract

The five-frequency model of Lidiard (A. B. Lidiard, Philos. Mag., 1955, 46, 1218, ) is the staring point for the calculation of the transport coefficients in binary dilute alloys. The tracer diffusion coefficient of the solvent atom is given by D(c) = D(0)(1 + bc), where b is the enhancement factor and c is the solute concentration. The most extensive calculation of the enhancement factor was given by Ishioka and Koiwa (S. Ishioka and M. Koiwa, Philos. Mag. A, 1984, 50, 505, ). Unfortunately, this result contains an unknown error, as revealed by Allnatt and Lidiard (A. R. Allnatt and A. B. Lidiard, Acta Metall., 1987, 35, 1555, ). We will point out an erroneous assumption in the calculation of Ishioka and Koiwa and propose a corrected formulation.