Attention was focussed on the conditions, that were required in order to perform and quantify weak-beam observations, with regard to linking the formation of a weak-beam image to the displacement field of the dislocation and to the diffraction geometry that was used to create it. The Cockayne-Ray-Whelan isotropic correction, which had been developed for the measurement of precise values of the partial dislocation spacing, was reconsidered. Comparisons between calculations which used anisotropic elasticity and image simulations highlighted the differences that existed between this method and the shifts that were predicted by image simulations. Although it was small for face-centered cubic metals, this difference was much larger for intermetallic alloys. Image simulations were also employed to stress the fact that experimental observations, especially those made beyond traditional weak-beam limits, could best be used to characterize dislocation structures when comparisons with simulated images were made.

Correlating Dislocation Core Structures with Weak Beam Transmission Electron Microscopy Observations. K.J.Hemker: Philosophical Magazine A, 1997, 76[1], 241-65