Graphene encapsulation provides unprecedented view of the diffusion and rotation of fullerene molecules

Scientists at the University of Vienna have created a new hybrid structure, termed buckyball sandwich, by encapsulating a single layer of fullerene molecules between two graphene sheets. Buckyball sandwiches combine for the first time soccerball-like fullerenes, each consisting of sixty carbon atoms, and graphene, a one-atom thick layer of carbon. This structure allows the scientist to study the dynamics of the trapped molecules down to atomic resolution using scanning transmission electron microscopy. They report observing diffusion of individual molecules confined in the two-dimensional space, find evidence for the rotation of isolated fullerenes within the structure, and even follow their merging into larger molecular clusters. Carbon is one of the most versatile elements: it forms the basis for an enormous number of chemical compounds, it has several allotropes of different dimensionality, and it exhibits many different bonding geometries. For this reason, carbon materials have had a special place in materials research for a long time. Although the three-dimensional forms of carbon-diamond and graphite'are known since ancient times, it took until 1985 before the first low-dimensional carbon allotrope, the quasi-zero-dimensional fullerene, was discovered.