Calculated structures for [001] symmetrical tilt grain boundaries in silicon

Abstract

The structures of [001] tilt boundaries in silicon have been systematically investigated by computer modeling, using the harmonic Keating potential to describe the interatomic forces. The full angular range of symmetrical tilt boundaries can be described in terms of linear combinations of characteristic groupings of atoms. More than one stable relaxed structure has been found for most grain boundaries. In all cases the relaxed bicrystal consists of localized groups of pure edge or 45° dislocation cores embedded in a tetrahedrally coordinated, stable structure.