High-resolution electron microscopy was used to investigate the defect structures in crystals of zincblende type using <110> beam incidence. It was concluded that there was a high density of 180° rotation twins. Under various imaging conditions, bright dots in the micrographs corresponded either to the atomic column pairs or to structural channels surrounded by atoms. These made the twin-boundary appear in different forms by changing the experimental parameters. End-on extended dislocations which were formed by the dissociation of 60° mixed dislocations and 0° screw dislocations with Burgers vectors of ½<110> type were analyzed. Using anisotropic elasticity theory, and the widths of dissociation measured from the above images, the stacking-fault energy on the {111} plane was determined to be 2.7mJ/m2. Frank dislocations located at the twin boundary, and a Hirth dislocation lock with a Burgers vector of 1/6<002> type were also observed.

An HREM Study of the Defects in ZnS. L.C.Qin, D.X.Li, K.H.Kuo: Philosophical Magazine A, 1986, 53[4], 543-55