The nucleation of partial dislocations from a surface was studied. A model was presented for 3 elementary cases that were related to the state of the surface (stepped or plane). A complex condition was analyzed which involved 2 Shockley partials that glided on the (111) plane of a face-centered cubic crystal with a (100) surface. The stress versus stacking-fault energy plane could then be divided into 3 parts where a complete dissociated dislocation or a partial dislocation would, or would not, nucleate.

Nucleation of Partial Dislocations from a Free Surface: a Theoretical Study. S.Brochard, N.Junqua, J.Grilhé: Philosophical Magazine A, 1998, 77[4], 911-22