The relation between the isotope effect for diffusion and the correlation factor in systems lacking a two‐fold symmetry around the tracer jump vector

It is investigated under which conditions the isotope effect, E , and the correlation factor, f , for diffusion by means of complex lattice defects (lacking a two‐fold symmetry around the tracer‐defect jump vector) are connected by E = f Δ K . In particular it is shown, that the conditions are fulfilled for (impurity) diffusion by divacancies and for diffusion by vacancy‐impurity pairs in f.c.c. metals.