The competition between 2 alternative positions (shuffle or glide {111} plane sub-sets) for the core of a 30º partial dislocation was examined. By using a combination of ab initio total-energy calculations, and finite-temperature free-energy calculations based upon an interatomic potential, free energies were obtained for the relevant vacancy-type core defects. In general, the free energy of vacancy formation in the core of a 30º glide partial dislocation was considerably lower (by more than 1eV) than that in the bulk. Even at high temperatures, the predicted thermal concentration of shuffle segments consisting of a row of vacancies in the core was low; placing the 30º partial dislocation in the glide sub-set position.

Vacancy Interaction with Dislocations in Silicon - the Shuffle-Glide Competition J.E.Justo, M.De Koning, W.Cai, V.V.Bulatov: Physical Review Letters, 2000, 84[10], 2172-5