Strain and rotation fields of dislocations in graphene

TL;DR

This paper introduces a regularized elasticity theory for dislocations in graphene, accounting for finite strain and rotation fields, and determines material constants from experimental data to better understand dislocation behavior.

Contribution

It develops a derivative regularization of linear elasticity that explicitly includes rotation, providing finite fields and core size parameters for dislocations in graphene.

Findings

Finite strain and rotation fields are mapped experimentally.

Regularized theory predicts finite dislocation core fields.

Two material constants are identified from experimental data.

Abstract

Strain and rotation fields of dislocations in monolayer graphene have been mapped in a recent experiment. These fields are finite everywhere and differ from those given by linear elasticity which does not consider rotation explicitly and predicts infinite rotation and strains at the dislocation point. A derivative regularization of two-dimensional linear elasticity fixes these shortcomings. The theory adds rotation, dislocation and residual strain energies to the usual elastic energy. There are two extra material constants that determine the size of the dislocation core and are determined from experimental data. These findings are useful for studies of dislocations in graphene and for analyzing incipient plasticity in two dimensional crystals.