Critical misfit for dislocation stability in self‐assembled islands

The energy of a dislocation within a coherently strained nanostructure is calculated as a function of misfit and position. If the misfit is decreased below a critical value, no energetically stable position for the dislocations exists inside the island. This instability is understood in terms of a simple two‐dimensional model and we propose that this can lead to motion of the nanostructure across the surface by a novel crawl mechanism. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)