High-resolution electron microscopic images of dissociated dislocations, as observed by using a beam that was normal to the stacking fault plane, were simulated. Model structures which contained 2 types (30 and 90) of Shockley partial dislocation were constructed according to elastic strain-field considerations, and were relaxed using a Keating-type potential. By varying the film thickness, and the depth of the dislocation within the film, it was revealed that stacking-fault images which were represented by a superlattice contrast with 3 x 3-R30 2-dimensional periodicity could be obtained by using films that were thinner than about 5nm. Also, the best contrast was found for a defocus that was shorter than the Scherzer focus. Under weak contrast conditions, a super-periodic modulation was discernible along the dislocation line and was attributed to reconstruction of the 30 partial dislocation core.

E.Kanematsu, M.Inoue, H.Amasuga, M.Nakamura, K.Maeda: Materials Transactions, 1996, 37[3], 273-8