A scanning tunnelling microscopic investigation was made of the emission of dislocations around nano-indentations in the form of dislocation arrangements (hillocks) consisting of 2 pairs of Shockley partial dislocations; each encompassing a stacking fault. The spatial arrangements and size distributions of hillocks around nano-indentation traces were studied. It was shown that standard dislocation theory for an isotropic continuum could be

used to describe the stability of the hillocks, their size and spatial distribution and the broadening of the corresponding extended dislocations near to the surface. A model was proposed in which hillocks originated from the splitting, into partial dislocations, of primary perfect dislocation loops; punched into the crystal by the scanning tunnelling microscope tip. This implied the existence of a novel dislocation mechanism which involved the long-range transport of matter over the surface.

Dislocation Configurations around a Nano-Indentation in the Surface of a FCC Metal. O.Rodríguez de la Fuente, M.A.González, J.M.Rojo: Philosophical Magazine, 2003, 83[4], 485-502