Electron Microscopic Images of Single and Intersecting Stacking Faults in Thick Foils. Part I: Single Faults

The bright‐ and dark‐field images of single and intersecting stacking faults have been studied; including the effects of anomalous absorption. In this, the first part of the paper, single faults are discussed. It is shown that the expressions for the amplitudes of the transmitted and scattered waves can be simplified considerably by introduction of a simple approximation. The properties suggested by the numerical calculations of HASHIMOTO et al., can then be expressed and discussed in a more precise analytical way, and additional properties found. In particular, it is possible to show how the central part of the fringe pattern depends on the foil thickness. The practical method developed by ART et al. for the determination of the nature of a fault in f.c.c. crystals is re‐examined, and it is shown that sufficient data can be obtained from the dark‐field image alone. The above theory is in general agreement with experiment.