The coupling of compositional changes and ordering, in the initial stages of interdiffusion, was considered by using both phenomenological and microscopic approaches. In the case of the phenomenological model, the diffusivity was assumed to depend exponentially upon the local order parameter. The relaxation of local order was described by a linearized reaction in which the equilibrium order depended upon the local composition. This led to non-monotonic ordering for a range of parameters. Monte Carlo simulations of ordering during interdiffusion on square and triangular lattices gave similar results. In addition, local blinking of ordered domains was observed in the contact zone. The magnitude of the deviations from monotonic ordering depended upon the initial concentration step at the interface of the diffusion couple.

Oscillatory Regime of Ordering during Interdiffusion A.M.Gusak, A.O.Kovalchuk: Physical Review B, 1998, 58[5], 2551-5