Intensity Profiles for Fringe Patterns Due to Planar Interfaces as Observed by Electron Microscopy

Abstract

Abstract Fringe profiles occurring at planar interfaces are discussed on the basis of a new simple theory. The theory can be used to derive the contrast at stacking faults or antiphase boundaries (α‐boundaries), coherent domain walls (δ‐boundaries), and at coherent interfaces of a mixed nature ((α — δ)‐boundaries). Explicit expressions for the transmitted intensity I T and the scattered intensity I S are derived from the dynamic two‐beam theory for electron diffraction, taking anomalous absorption into account. The effect of the various physical parameters involved is analysed on the basis of these expressions. Very fine image details can be explained or predicted, which lead to identification of the physical origin of the observed contrast features, and enable the sign of α to be determined. The analysis is supported by computed profiles, and a particular case is discussed for which the present method is applicable.