Abstract
The influence of dislocation core structure upon the relationship between the separation of Shockley partial dislocations and the stacking‐fault energy (γ) of materials crystallising with a close‐packed structure is investigated. It is shown that for the same separation of the partial dislocations a wide range of values of γ can be obtained assuming various core models. The relevance of these conclusions to measurements of the separations of partial dislocations using high resolution electron microscopy is discussed, and the importance of the various core parameters in the interpretation of the microscope images is considered.