Behavior of Vacancies and Interstitials at Semicoherent Interfaces

Using atomistic simulations on a model semicoherent interface, we show that the formation, migration, and clustering of vacancies and interstitials at semicoherent interfaces depend on the structure of the misfit dislocation network of the interface. Interfacial point defects trap at misfit dislocation intersections and migrate from one intersection to another along misfit dislocations by a multistage process. Interfacial point defect clusters are thermodynamically less stable than individual defects and the largest cluster size depends on the spacing between misfit dislocation intersections. Our results show that the behavior of interfacial point defects is intimately connected to interface structure.