Atomically sharp edges revealed in a self-folded graphene nanostructure*

The crystallographic orientation of the edges of graphene nanostructures is of particular interest as it can strongly affect the electronic, optical, or magnetic properties of the nanostructures. Here, we produced a folded graphene nanostructure by drawing lines on a mechanically exfoliated graphene monolayer while applying a moderate normal force of about 10 nN using an atomic force microscope (AFM) tip[1]. Drawing a line in this way induced self-folding in the graphene monolayer. We acquired several lateral force microscopy (LFM) friction images based on the nanoscale stick-slip phenomenon to investigate the crystallographic orientation of the exfoliated graphene edges and that of the self-folded graphene nanostructure edges. We found that there is a particularly favored crystallographic orientation in the self-folding process, and we will compare our results with previous studies investigating the edges of graphene folded using different methods.