Misfit dislocations and the alignment of epitaxial islands

Moiré fringes in electron images of three-dimensional islands on a substrate are often misaligned. In the past this misalignment has been assumed to be due to rotation of the islands away from the epitaxial orientation. It is suggested that an alternative explanation is possible: misaligned fringes can result from discrete changes in misfit strain which accompany the generation of individual misfit dislocations. The misalignment of fringes predicted on this model agrees with observations made on deposits of copper on nickel. © 1972.