Correlation Factor in Substitutional Diffusion in Binary Alloys

Abstract

The correlation factor is defined and derived by the path probability method of substitutional atomic diffusion (the vacancy mechanism) in binary alloys. The correlation factor thus defined is shown to be the same as that derived by the traditional random‐walk approach in all cases where the latter approach is capable of calculating the factor, namely in self‐diffusion, in impurity diffusion, and in randomly disordered alloys (excluding the nonpercolating limit in the last case). The calculation of the correlation factor is further extended by the path probability method to disordered and ordered alloys of arbitrary composition and arbitrary temperature. The relation of the present problem with the percolation problem is also discussed.