Mixed partial dislocation core structure in GaN by high resolution electron microscopy

The core structures of a 1/6 [2 (2) over bar 03] mixed partial dislocation in wurtzite GaN have been investigated using a combination of high resolution transmission electron microscopy, circuit mapping, and image simulation of relaxed models. HRTEM simulated images of relaxed atomic models, derived by energetic calculations with a modified Stillinger-Weber-type empirical interatomic potential, were calculated and compared to the experimental images. Among twenty-four stable core configurations the 12- and 10-atom rings satisfied the experimental contrast. A pattern registration procedure was used for the matching of simulated and experimental HRTEM images. (c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.