Abstract
Understanding dislocation core structure at the atomic level is of significant theoretical and technological importance because of the role dislocations play in the electronic/optical properties of materials. In this letter, we report our aberration-corrected scanning transmission electron microscopy study on misfit dislocation core structures at the ( ) ZnO/( ) Al2O3 (a-ZnO/r-Al2O3) interface, a nonpolar system that has recently drawn intensive research interest. The dislocations are found to be perfect edge dislocations with a Burgers vector of b = 1/3 Al2O3. The atomic configuration of the core structure is closely related to the preferred interfacial bonding configuration. A significant number of these misfit dislocations have undergone a core structure modification involving the incorporation of Zn in the Al2O3 side of the dislocation (under compression). This core structure modification appears to be effective in reducing the strain in the ZnO in the vicinity of the core.