title: Soliton instability and fold formation in laterally compressed graphene.
abstract: We investigate-through simulations and analytical calculations-the consequences of uniaxial lateral compression applied to the upper layer of multilayer graphene. The simulations of compressed graphene show that strains larger than 2.8% induce soliton-like deformations that further develop into large, mobile folds. Such folds were indeed experimentally observed in graphene and other solid lubricants two-dimensional (2D) materials. Interestingly, in the soliton-fold regime, the shear stress decreases with the strain s, initially as s(-2/3) and rapidly going to zero. Such instability is consistent with the recently observed negative dynamic compressibility of 2D materials. We also predict that the curvatures of the soliton-folds are given by r(c) = δ√(β/2α) where 1 ≤ δ ≤ 2 and β and α are respectively related to the layer bending modulus and to the interlayer binding energy of the material. This finding might allow experimental estimates of the β/α ratio of 2D materials from fold morphology.
authors.affiliation: Departamento de Física, Universidade Federal de Ouro Preto, Ouro Preto, MG, 35400-000, Brazil.
authors.forename: Amauri Libério
authors.initials: AL
authors.lastname: de Lima
authors.forename: Lucas A M
authors.initials: LA
authors.lastname: Müssnich
authors.forename: Taíse M
authors.initials: TM
authors.lastname: Manhabosco
authors.forename: Hélio
authors.initials: H
authors.lastname: Chacham
authors.forename: Ronaldo J C
authors.initials: RJ
authors.lastname: Batista
authors.forename: Alan Barros
authors.initials: AB
authors.lastname: de Oliveira