DISLOCATION STRUCTURES IN CLEAVED MAGNESIUM OXIDE.

Surface structures produced during cleavage of magnesium oxide are described and interpreted in terms of the production and motion of dislocations. The usefulness and applicability of the nucleation decoration technique to obtain high resolution micrographs of surface structures is presented. The observed surface structures are described in terms of production and termination of line pairs associated with the cutting of screw components, the interaction of dislocation half-loops with the surface and the occurrence of cross-glide and of dislocation multiplication. Author