A single point defect diffusion near a Cu (100) surface

Abstract

As part of our investigations on the disordering of metal surfaces, we report the results of our calculations of the energetics of formation and migration of a single point defect (vacancy and interstitial) in the Cu (100) surface using molecular dynamics method. We used the embedded-atom method to describe inter-atomic interactions. Defect formation and migration energies have been calculated at the surface as well as in the near-surface region. Vacancy and interstitial formation and migration energies converge to bulk values already at a few layers below the surface. We find that the surface vacancy and interstitial formation and migration energies are all lower than their bulk values. For the inter-layer migration, a point defect in each of the first six layers is favorable to migrate into the corresponding upper layer, especially for the first three layers.