On the ambiguity between moiré fringes and the electron diffraction contrast from closely spaced dislocations

Parallel fringes seen at, e.g., sub-boundaries on electron micrographs are sometimes interpreted as moiré fringes and sometimes as due to dislocation contrast effects. It is shown here that if dislocations are sufficiently close together (less than one extinction distance), they give rise to a fringe system which is indistinguishable from moiré fringes. Experiments performed on two alloys confirm the theory.