Box-shaped graphene – a novel nanostructure

A scientist from the Institute of Physical Problems named after F. V. Lukin in Zelenograd, Russian Federation, has discovered a previously unknown three-dimensional nanostructure consisting of graphene sheets.

The researcher, Dr. Rostislav Lapshin, a staff scientist at the institute, has reported his findings in the January 1, 2016 edition of Applied Surface Science ("STM observation of a box-shaped graphene nanostructure appeared after mechanical cleavage of pyrolytic graphite").

Graphene is a single monolayer of carbon atoms forming a hexagonal two-dimensional crystal lattice. The discovered nanostructure is a multilayer system of parallel hollow channels with quadrangular cross-section extending along the surface.

The thickness of the channel walls/facets of the nanostructure is about 1 nm, the width of the channel facets is approximately 25 nm, and the channel length reaches at least several hundreds of nanometers.

Dr. Lapshin explains: "Actually, graphite crystal can be thought of as a stack of graphene sheets. Graphite surface under a scanning tunneling microscope (STM) looks 'dull' and uniform. Usually, one may see plain areas of surface of several microns in size bounded by cleaving steps without any features. Only rarely does the familiar 'landscape' contain something unusual, for example, a carbon fiber, a superlattice or a dislocation network."

The discovered nanostructure looked so extraordinary that it took some time to understand what it actually was. The structure was dramatically different from whatever had previously been observed on graphite.