The intermixing (and associated interdiffusion) resulting from ion implantation of argon ions into Cd1−xMnxTe quantum‐well structures has been investigated. The experimental value of the mixing parameter of 1.5×103A˚/eV is large compared with the values reported for this parameter in metallic superlattices, and is consistent with an appreciable degree of inter diffusion accompanying the implantation process. ©1996 American Institute of Physics.