New potential model for atomic-scale peeling of armchair graphene: toward understanding of micrometer-scale peeling

Abstract

We developed a new potential model to simulate the adhesive characteristics of the peeling process of an armchair-type graphene sheet from a frictionless graphite substrate surface. First the transition of the shape of the graphene sheet and the vertical force curve during the peeling process obtained by this model successfully reproduced those obtained by our previous model. The computation time by this potential model is reduced to 1/6400 compared to that by our previous model. Next this potential model was extended to include the effective stiffness of atomic force microscopy (AFM) which consists of the stiffness of the cantilever, tip and contact region. A characteristic step structure of the vertical force curve is obtained by the extended model. Our approach opens new directions for multiscale physics of the peeling process of a π-conjugated sheet from atomic-scale to micrometer-scale, and interpretation of force-spectroscopy observed by AFM.