Simulations were made of dislocation sources in order to determine how dislocation dynamics and multiplication governed the initial stages of plastic flow in diamond cubic crystals. An existing numerical method was modified by introducing specific dislocation properties that arose from the presence of strong Peierls forces. The effects of stress and temperature upon the dynamics and configurations of Frank-Read sources were examined on {111} sections of model crystals which had dimensions that were larger than 1002. It was found that most of the results which were obtained could be interpreted qualitatively in terms of the various contributions to the effective stress which acted upon dislocation segments, and in terms of the nature of the stress versus velocity laws for Si. Back-stresses on the slip plane and on the cross-slip plane were investigated in detail under upper yield point conditions. These results provided numerical data for a recently proposed model for mechanical twinning in semiconductors.

A.Moulin, M.Condat, L.P.Kubin: Acta Materialia, 1997, 45[6], 2339-48