Ripplocation and kink boundaries in graphene/copper nanolaminates: A molecular dynamics study

Abstract

Over the past decade, four distinct differences have been summarized regarding ripplocation and kink boundaries in layered solids: spontaneous reversibility, atomic sharpness, delamination, and residual stress. However, according to molecular dynamics simulations, these four distinct differences are not completely applicable to the ripplocation and kink boundaries in graphene/copper nanolaminates. Contrary to conventional understanding, ripplocation boundaries can transform into kink boundaries without triggering the collective movement of other ripplocations. In addition, ripplocation boundaries can be irreversible with out-of-plane slip, leading to coherent twins in [110] orientation and stacking faults in [111] orientation. Moreover, delamination only occurs at kink boundaries rather than ripplocation boundaries. Wide-spreading residual stresses are absent for both ripplocation and kink boundaries due to plasticity. These findings broaden the current understanding of ripplocation and kink boundaries in layered solids.