The various possible configurations for an undissociated screw dislocation in group-IV materials (Ge, Si, 3C-SiC, diamond) were examined by means of semi-empirical atomistic calculations. A complete structural characterization and a determination of the relative stability were performed. It was found that, in contrast to the case of Ge and Si, a geometry which involved the presence of sp2 atoms in the core was the most stable structure for 3C-SiC and diamond. This yielded a stable screw dislocation configuration in the glide set for 3C-SiC and diamond.

Stability and Core Structure of Undissociated Screw Dislocations in Group-IV Materials Investigated by Means of Atomistic Calculations. L.Pizzagalli, P.Beauchamp, J.Rabier: Journal of Physics - Condensed Matter, 2002, 14[48], 12681-8