The study of faulted dipoles in copper using weak-beam electron microscopy

Abstract
The weak-beam method of electron microscopy has been used to study faulted dipoles in pure copper. Micrographs of these defects have been compared with many-beam computed images and the dipole geometry defined with a greater accuracy than hitherto possible using conventional imaging techniques. Previous strong-beam studies of faulted dipoles in copper are discussed. Analysis of the weak-beam images using anisotropic elasticity theory gives an upper limit for the stacking-fault energy of γ MAX = 47 ± 8 erg cm−2. It is concluded that similar studies are potentially very useful for estimating the stacking-fault energy of materials for which γ and the elastic constants are such that the dissociation of single dislocations cannot be resolved.