Dislocation nucleation from a stressed crystalline surface was analyzed on the basis of the Peierls–Nabarro dislocation model. The variational boundary integral approach was used to obtain profiles of the embryonic dislocations in various 3-dimensional nucleation configurations. The stress-dependent activation energies which were required to activate dislocations from stable to unstable saddle-point configurations were determined. The present analysis eliminated the uncertainty of a core cut-off parameter by allowing for the existence of an extended dislocation core as the embryonic dislocation evolved. Atomic information could be incorporated so as to reveal the dependence of the nucleation process upon the profile of the atomic interlayer potential; as compared with continuum elastic dislocation theory, where only elastic constants and Burgers vectors were relevant.

Analysis of Dislocation Nucleation from a Crystal Surface based on the Peierls–Nabarro Dislocation Model. G.Xu, C.Zhang: Journal of the Mechanics and Physics of Solids, 2003, 51[8], 1371-94