An analysis of weak-beam α Fringes formed by systematic diffractions

Abstract
The weak-beam image of a fault type interface (weak-beam α-fringe) characterized by the translation of the neighbouring crystals has been re-examined. The displacement of the thickness fringe at the interface with only one set of systematic diffraction is proved to coincide with that of a two-beam state under a sufficiently weak diffraction condition. The direct measurement of the lattice displacement at the interface previously reported is therefore valid.