Path of ordering under confinement in alloy films

The effects of surface confinement on the kinetics of ordering in fcc alloy films are studied by the Monte Carlo method. Under weak surface confinement, there are two kinds of kinetic path for alloy films with even layer. One is the films directly relaxing to the equilibrium state, the other is the films relaxing to a metastable state first. Even for the same initial atomic configuration, the kinetic path of ordering is randomized, and the possibility that the films relax to a metastable state is independent with the initial atomic configurations. We attribute this randomicity to the competition between surface confinement and chemical ordering. The evolution of the metastable state to the equilibrium state is also simulated. The results indicate that an alloy film with weak surface segregation can easily be trapped into metastable state.