Results obtained by atomic computer simulation, based upon an adapted Stillinger–Weber potential, of the structure and relative stability of lattice dislocations, tilt and twin boundaries in GaN were described. The method used for the search and description of all possible atomic configurations depended upon the crystallographic structure. It was consequently of general application and the results were transferable to wurtzite binary compounds. On the other hand, the relaxed structures and their relative energetic stabilities were potential-dependent. The results presented corresponded to a GaN model described by a pair potential. Whenever possible, these results were compared with experiments or with ab initio calculations. The core shape and energy of crystal dislocations of both edge and screw type, [00▪1] tilt boundaries with misorientation angles ranging from 9.3° (corresponding to Σ37) to 44.8° (corresponding to Σ43) and twin boundaries were presented. The atomic structures of the tilt boundaries could be described in terms of the 3 stable structures of the prism-edge dislocation core. The twin boundary was entirely described by 6-coordinated channels, whereas the other twin boundaries presented more complex structural units.

On the Atomic Structures, Mobility and Interactions of Extended Defects in GaN: Dislocations, Tilt and Twin Boundaries. A.Béré, A.Serra: Philosophical Magazine, 2006, 86[15], 2159-92