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 1.5x10(3) Angstrom/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. (C) 1996 American Institute of Physics.