Concentration characteristics of diffusion-induced recrystallization in Cu/CuAu multilayers of varying lattice mismatch

New grains appear in Cu/Au(Cu) thin film interdiffusion couples by diffusion-induced recrystallization. These grains are grouped into different generations of characteristic concentration levels. In this study, the lattice mismatch between initial diffusion partners is systematically varied. It is demonstrated that the intermediate concentrations shift parallel to the concentration of the initial layers. Thus, the characteristic compositions are controlled by the requirement of a characteristic lattice mismatch between parent layer and new grain rather than by metastable phases or highest chemical driving forces.