The atomic structures of (10▪1), (10▪2), and (10▪3) twins in the wurtzite GaN were studied by atomic computer simulation using an empirical interatomic potential of the Stillinger-Weber type. Distinct reference structures were considered with respect to the type planes of the two adjacent crystals. The atomic structure of the twin boundaries was found to be dependent on these starting configurations. The lowest energy structure of the (10▪3) boundary was composed by 6-coordinated channels whereas the (10▪2) twin boundary could present three distinct structures composed by either 4-, 8-, or 5/7-coordinated channels separated by 6-coordinated channels. In both cases there was a mirror symmetry relating the two crystals. In the (10▪1) twin the two structures of low energy did not exhibit mirror symmetry and present corrugated boundary planes.

Atomic Structures of Twin Boundaries in GaN. A.Béré, A.Serra: Physical Review B, 2003, 68[3], 033305 (4pp)