Ripplocations in layered materials: Sublinear scaling and basal climb

Abstract

The ripplocation is a crystallographic defect which is unique to layered materials, combining nanoscale delamination with the crystallographic slip of a basal dislocation. Here, we have studied basal dislocations and ripplocations, in single and multiple van der Waals layers, using analytical and computational techniques. Expressions for the energetic and structural scaling factors of surface ripplocations are derived, which are in close correspondence to the physics of a classical carpet ruck. Our simulations demonstrate that the lowest-energy structure of dislocation pileups in layered materials is the ripplocation, while large dislocation pileups in bulk graphite demonstrate multilayer delamination, curvature, and voids. This can provide a concise explanation for the large volumetric expansion seen in irradiated graphite.