A detailed study was made of mixed dislocations, in which the complexities of the atomic arrangements in the cores were imaged directly for the first time by using an aberration-corrected scanning transmission electron microscope. In addition to being present as a full-core structure, the mixed dislocation was observed to dissociate into partial dislocations; separated by a stacking fault only a few unit cells in length. The generation of this stacking fault appeared to be impurity-driven, and its presence was consistent with theoretical predictions of dislocation dissociation in materials with hexagonal crystal symmetry.

Atomic and Electronic Structure of Mixed and Partial Dislocations in GaN. I.Arslan, A.Bleloch, E.A.Stach, N.D.Browning: Physical Review Letters, 2005, 94[2], 025504 (3pp)