STRUCTURE AND CHARACTERIZATION OF THE DISLOCATIONS IN TILT GRAIN-BOUNDARIES BETWEEN SIGMA = 1 AND SIGMA = 3 - A HIGH-RESOLUTION ELECTRON-MICROSCOPY STUDY

It is shown that the displacement shift complete (DSC) lattice is no longer necessary to define the Burgers vector associated with an interfacial dislocation. In Si and Ge [011] perfect or imperfect bicrystals, the grain boundary atomic structure is made of a limited number of structural units (SUs). Using high resolution electron microscopy (HREM), it is shown that one SU can be considered as the core of a grain boundary dislocation whose Burgers vector can be easily defined on the HREM image. The limited number of SUs strongly restricts the possible Burgers vectors compared with the DSC lattice vectors. These experimental results provide a link between the geometrical approach developed by Pond and the energetic approach developed by Sutton and Vitek.