Deformation mechanism of ripplocation in multilayer graphene

Abstract

Recently, a new defect known as ripplocation has been discovered in materials with layered structures. In this study, we elucidate the affecting factors in multilayer graphene (MLG) of ripplocation deformation by combining mechanics and mathematics. We perform a molecular dynamics simulation to generate ripplocation deformation by applying local strain to an ABA-type MLG in the armchair direction. The effects of number of graphene layers and graphene widths on ripplocation boundaries (RBs) are discussed comprehensively. Results show that when other conditions remain unchanged, a smaller number of compressed graphene layers and a longer width result in the generation of more RBs with two opposite signs. Furthermore, lattice dislocations are introduced into an ideal MLG to investigate the effect of number of dislocations on the generation of RBs with two opposite signs. We propose a mathematical method using differential geometry to evaluate the mean curvature and obtain a linear relationship between the potential energy and the square of the mean curvature of compressed graphene layers. These results are crucial for evaluating the boundary conditions of corrugated nucleation in layered structures. The proposed method for elucidating ripplocation deformation mechanisms at the nanoscale can be extended to the elucidation of ripplocation behavior in multiscale fields, such as the evaluation of ripplocation deformation of soil layers caused by earthquakes.