STM observation of a box-shaped graphene nanostructure appeared after mechanical cleavage of pyrolytic graphite

⿢A previously unknown 3D box-shaped graphene (BSG) nanostructure has been detected.⿢The nanostructure is a multilayer system of parallel nanochannels having quadrangular cross-section.⿢Typical width of a nanochannel facet makes 25 nm, typical wall/facet thickness is 1 nm.⿢A mechanism qualitatively explaining the nanostructure formation has been proposed.⿢Possible applications of the BSG nanostructure are briefly discussed.