Surface stresses and vacancies

Abstract

Atomistic calculations for surface stress and the effect of vacancies on the surface stress have been carried out using a two-dimensional embedded-atom method model. Stresses due to the presence of the surface are large, localized within a few atomic planes of the surface and vary rapidly with depth with the net stress being a tension. The effect of vacancies at or near the surface is not localized within a few atomic planes of the surface, reduces the tension if in contact with the surface but increases the tension if below the surface. Vacancy configurations which provide the greatest relaxation of surface tension are generally not those with the lowest energy. None of these results should be specific to a two-dimensional model.