Intrinsic mobility of a dissociated Dislocation in silicon

Dislocation velocities in silicon in the experimental range of temperature and stress are studied a priori by combining a mechanistic treatment of ele mentary kink processes with activation energies obtained by atomistic calcu lations. Pronounced effects of intrinsic coupling of the dissociated partia l dislocations are captured in kinetic Monte Carlo simulations, which are c onsistent with observed velocity variations with applied stress. As a resul t, the nature of "weak obstacles" to kink propagation, a long-standing post ulate in previous data interpretation, is clarified. A striking new effect is predicted and offered for experimental verification when dislocation vel ocity shows nonmonotonic oscillatory behavior with increasing stress.