Dislocation nucleation from near surface void under static tensile stress in Cu

We examine a possible mechanism for the formation of protrusions on a metallic surface held in a sufficiently high electric field in the presence of a near-surface void. By means of molecular dynamics simulations we show that the high tensile stress exerted on a Cu {110} surface with a near-surface void can promote the nucleation of dislocations on the void surface. These dislocations cause slip along {111} crystallographic planes leading to mass transport in the volume above the void. We find a linear correlation between the radius of the void and the maximum depth for the growth to occur. (C) 2011 American Institute of Physics. [doi:10.1063/1.3606582]