Novel deformation mechanism of twinned nanowires

This letter reports a novel deformation mechanism of twinned Cu nanowires, based on molecular statics and dynamics simulations. Under mechanical loading, Shockley partial dislocations nucleate and glide on a {111} plane toward a twin boundary. Upon penetration of the twin boundary, a dislocation with Burgers vector of $\frac{1}{2}⟨110⟩$ nucleates and glides on a {100} plane, instead of conventional {111} planes. The dislocation nucleation on {100} planes is facilitated by the intersection of surface and twin boundary, and the dislocation glide is primarily facilitated by the matching of Burgers vector along the normal direction of the twin boundary.