Monte Carlo simulation of the initial disordering rate of Cu3Au under ion irradiation

The temperature dependence of disordering of Cu3Au during ion irradiation has been investigated by computer simulations using MONTE CARLO methods. The investigation was motivated by peculiar experimental observations that the initial disordering rate begins to decrease above similar to 300 K, which can be explained by vacancies just becoming mobile at that temperature, but then at similar to 475 K, it reaches a minimum and then increases rapidly as the temperature is further increased, up to the order-disorder temperature. The present simulation shows that this behavior can be understood in terms of temperatures dependencies in both atomic mixing in the cascade and the efficiency of vacancy annealing of disorder as the vacancies diffuse out of the cascade.