Analysis at atomic level of dislocation emission and motion around nanoindentations in gold

Scanning tunnelling microscopy of a reconstructed Au(0 0 1) surface shows that two types of dislocation configuration are created by nanoindentation: ‘mesa’-shaped dislocation loops and ‘screw’ dislocation loops. We analyse the generation of these loops at the initial stages of plastic deformation of the surface, their glide and cross-slip and their interaction with existing steps on the surface. We also show that the standard dislocation theory for an elastic continuum adequately explains the observed dislocation configurations, their spatial distribution, motion and interaction with other defects.