A single vacancy diffusion near a Fe (1 1 0) surface: A molecular dynamics study

Both the formation energies, the intra-layer and inter-layer diffuse migration energies of a single vacancy in the first nine layers of the Fe (1 1 0) surface have been calculated by means of molecular dynamics in conjunction with the many-body potential of the embedded-atom method (EAM). The results show that the effect of the surface is only down to the fourth layer for the formation energy of a single vacancy. However, the surface presence affects the migration energy down to the seventh layer. It is easier for a vacancy in the first layer to form and to migrate than in the other layers and the bulk. For the inter-layer migration, a vacancy in each of the first six layers is favorable to migrate into the corresponding upper layer, especially for the first three layers.