Analysis of strain in the {11(2)over-bar-0} prismatic fault in GaN using digital processing of high-resolution transmission electron microscopy images

摘要

Using the geometric phase method and measurements of dislocation core distributions, a quantitative analysis of the contrast exhibited by [0001] HRTEM images of the {11 (2) over bar0} prismatic stacking fault in GaN was carried out. Such analysis allows precise determination of the displacement vector and location of any additional defects inside the boundary, such as steps and dislocations. For relaxed segments, a perfect matching between experimental and simulated images based on the Drum model was obtained. When stress fields are present, the deviation of the atomic structure of the boundary from the theoretical models is significant. Lattice reconstruction inserts fragments of additional planes in the boundary and dislocations are revealed. [References: 11]