It was noted that the dislocations which were introduced by plastic deformation of the wurtzite structure had mainly a-type Burgers vectors. The dislocations on prismatic planes were not dissociated when observed using weak-beam electron microscopy. High-resolution electron microscopy of basal dislocations revealed that both the dissociated and undissociated states were stable. From the widths of dissociated basal dislocations, as observed using weak-beam electron microscopy, the energy of the intrinsic stacking fault was estimated to be equal to 22mJ/m2. This value was consistent with a correlation which had previously been found between the reduced stacking-fault energy and the c/a ratio of wurtzite crystals.

Electron Microscopy of Dislocations Introduced into GaN by Plastic Deformation K.Suzuki, S.Takeuchi: Philosophical Magazine Letters, 1999, 79[7], 423-8