The initial stages of misfit relaxation, in Ge epitaxial films that had been grown in a 2-dimensional (layer-by-layer) manner onto Si(001), were investigated by means of high-resolution transmission electron microscopy. Particular emphasis was placed on dislocation interactions which led to rearrangements, in a non-equilibrium dislocation network, that were driven by elastic interactions between parallel 60 dislocation segments. One of the dislocation reactions, between closely spaced misfit segments which could not combine to form a 90 pure edge dislocation, was analyzed in detail. On the basis of the experimental observations, a model was proposed for the formation of stacking faults in heterostructures. The energetics of the various dislocation reactions which were involved, and the splitting of 60 dislocations to create stacking faults, were considered.

S.Oktyabrsky, J.Narayan: Philosophical Magazine A, 1995, 72[2], 305-14