Vacancy interaction with dislocations in silicon: the shuffle-glide competition
Competition between the two alternative positions (shuffle and glide 111 plane subsets) for the core of a 30 degrees partial dislocation in Si is examined. Using a combination of ab initio total energy calculations with finite temperature free-energy calculations based on an interatomic potential, we obtained free energies for the relevant vacancy-type core defects. Generally, the free energy of vacancy formation in the core of a 30 degrees glide partial dislocation is considerably lower (by more than 1 eV) than in the bulk. However, even at high temperatures, the predicted thermal concentration of the shuffle segments comprised of a row of vacancies in the core is low, placing the 30 degrees partial dislocation in the glide subset position.
Justo
JF
Instituto de Fisica da Universidade de Sao Paulo, CP 66318, CEP 05315-970, Sao Paulo-SP, Brazil.
de Koning M
Cai
W
Bulatov
VV