Partial secondary dislocations in germanium grain boundaries

Abstract

Abstract Interfacial dislocation networks have been studied in germanium bicrystals, using transmission electron microscopy. Periodic arrays of partial secondary dislocations, associated with a stacking-fault-like structure, have been observed in a near coincidence Σ=5 grain boundary in which the deviation from exact coincidence orientation is a 0·05° rotation about [131], close to the boundary normal [130]. The dislocation grid is made of a honeycomb network of two partial secondary dislocations and a perfect secondary dislocation crossed by a set of parallel partial secondary dislocations. When some diffracting vectors common to the two crystals are used, areas of different contrast, limited by the partial dislocations, appear suggesting that the boundary is formed by two interfacial domains.