An unexpected characteristic of dislocation cores in silicon was reported. Using first-principles calculations, it was shown that all of the stable core configurations for a non-dissociated 60° dislocation were sessile. The only glissile configuration, previously obtained by nucleation from surfaces, surprisingly corresponds to an unstable core. As a result, the 60° dislocation motion was solely driven by stress, with no thermal activation. It was predicted that this original feature could be relevant in situations for which large stresses occurred, such as mechanical deformation at room temperature. The results also suggested that post-mortem observations of stable dislocations could be misleading and that mobile unstable dislocation cores should be taken into account in theoretical investigations

Glissile Dislocations with Transient Cores in Silicon. L.Pizzagalli, J.Godet, S.Brochard: Physical Review Letters, 2009, 103[6], 065505