Monte Carlo simulation of the CuAg (001) semicoherent interphase boundary

The structure and composition of the CuAg (001) semicoherent interphase boundary in the temperature range 600-900 K is investigated with Monte Carlo simulation, using the embedded atom method to model the atomic interactions. Parts of the CuAg phase diagram are calculated and found to be reasonably good agreement with experimental data. The interface, which contains an excess of Ag, is found to broaden with increasing temperature. The distribution of Cu and Ag in the layers adjoining the interface is non-uniform, with the larger Ag atoms tending to cluster in regions of tension, while the smaller Cu atoms tend to cluster in regions of compression. These regions of compression and tension are associated with the positions of the interfacial misfit dislocations. At higher temperatures the misfit dislocations wander due to thermal disordering, and the at the highest temperature the identity of the dislocations is lost, possibly indicating the transition from a semicoherent to an incoherent interface.