| A model is suggested that describes the generation of dislocations in twinned nanowires under tension. The critical stress for dislocation formation in deformed twinned nanowires is calculated. It is shown that the strong twin size dependence of the critical stress is associated with the nanowire surface effects, such as dislocation attraction by the nanowire surface and the presence of the surface steps and surface stresses. The calculations demonstrate that the dependence of the critical stress on the nanowire twin thickness can be described by a Hall-Petch type relation, in agreement with recent experimental data. |
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