Results obtained by atomic computer simulation based on an adapted Stillinger-Weber (SW) potential concerning the structure and relative stability of lattice dislocations, tilt and twin boundaries in GaN were discussed. The method used for the search and description of all possible atomic configurations depends on the crystallographic structure; consequently it was of general application and the results were transferable to the wurtzite binary compounds. On the contrary, the relaxed structures and their relative energetic stability were potential dependent. The results presented here correspond to a GaN model described by a pair potential. Whenever it was possible the results were compared with experiments or with ab initio calculations. The core shape and energy of a and c crystal dislocations of both edge and screw character were presented; [00▪1] tilt boundaries of misorientation angles from 9.3° (corresponding to Σ37) to 44.8° (corresponding to Σ43) and (10▪n) twin boundaries (n = 1, 2, 3). The atomic structures of the tilt boundaries could be described in terms of the 3 stable structures of the prism a-edge dislocation core. The (10▪3) twin boundary was entirely described by 6-coordinated channels whereas the other twin boundaries present 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