Crater formation via homoepitaxy of adatoms dislodged from reducing oxide islands on metal surfaces

The reduction of Cu2 O islands on Cu(100) surfaces under vacuum annealing leads to the formation of surface craters on the substrate surface surrounding the reducing oxide islands. These craters exhibit growth instability characterized by increased slope of both the inner and outer facets of the crater rims. We suggest that the crater formation and the growth instability are related to the homoepitaxial growth of Cu adatoms dislodged from the reducing Cu2 O islands. Incorporation of such atomic processes in kinetic Monte Carlo simulations reproduces the morphological features of the experimentally observed craters.