Surface step-dislocation transition and dislocation nucleation at a solid free surface

An edge dislocation leaving a crystal forms a step at the free surface. To minimize the surface energy, the step gradually relaxes so that the elastic energy does not tend to zero when the dislocation leaves, resulting in a modification of the force on the dislocation. Stress and energy calculations are presented, taking the surface energy into account, and the resulting force on a near surface dislocation is determined. Dislocation nucleation at a surface step is briefly discussed.