Dissociated 60° dislocations in CdTe studied by high-resolution electron microscopy

High-resolution electron microscopy has been used to characterize disclocations in CdTe which were induced by argon ion-beam milling. The core structures of the 30° and 90° partial dislocations resulting from the dissociation of 60° dislocations have been analysed with assistance from multislice image simulations, and it is found that various structural models (glide set and shuffle set) can be differentiated. Chemical information (α or β form) about the dislocations can be deduced by first determining the Burgers vectors of the dislocations and the crystal polarity. Experimentally, for a 60° dislocation dissociated with an intrinsic stacking fault, the 30° partial is found to be the glide set, independent of its chemical nature; however, no shuffle set is found. For a 60° dislocation dissociated with an extrinsic stacking fault, the 90° partial is usually kinked and therefore much more difficult to recognize. In one particular example, however, it was found to be the glide set.