Analysis of the Cermak–Rothova method for determining the concentration dependence of ternary interdiffusion coefficients with a single diffusion couple

Dayananda’s method for calculating the average ternary interdiffusion coefficient (D̃¯ij3) using a single diffusion couple has recently been extended by Cermak and Rothova to determine the composition-dependent interdiffusion coefficients (D̃ij3) in ternary systems based on the limitation of limx1→x2D̃¯ij3=D̃ij3 in the distance interval . In the present paper, the authors argue that such a limitation is not applicable, and the so-called Cermak–Rothova approach cannot be used to obtain the “truly” composition-dependent interdiffusion coefficients.