Stable carbon structures: fullerene + Cn + graphene where Cn is a liner cluster

Abstract

Structures formed by fullerene and graphene, interconnected by either a linear carbon cluster with the number of atoms from 2 to 5, or only by one carbon atom, have been studied by the methods of computational simulation. A simple covalent interaction of fullerene with graphene with no binding atoms and clusters has been considered and characteristics of noncovalent interaction of fullerene with graphene have been calculated. Stability of the fullerene-cluster-graphene structures is defined by covalent bonds of carbon atoms, which we set within the Brenner potential of the second generation (REBO), and by non-covalent interaction of fullerene with graphene, which is set by the Lennard-Jones interatomic potential. Fullerene in the structure of the fullerene-cluster-graphene is well fixed to a specific place owing to covalent bonds; this feature of the structures favorably differs from the case of the easily moving fullerene over the graphene surface, if it is necessary to rigidly fix fullerene on graphene. It is shown that good binding of fullerene with graphene is achieved by carbon clusters, and the best binding, if the cluster is diatomic, binding by one carbon atom also leads to a stable structure. A simple covalent bonding of fullerene with graphene is less stable. For the models of fullerene-cluster-graphene to be obtained, main computational simulation is performed step-by-step, starting with the models of free carbon linear clusters, defect-free fullerene and ideal graphene, and then simulation of fullerene binding with clusters is carried out; further binding of fullerene-cluster with graphene is simulated with taking into account non-covalent interaction of fullerene with graphene. The comparison of the calculated values of the binding energy has demonstrated which structures are more stable and how non-covalent interaction influences stability. By analyzing the obtained structures of fullerene-cluster-graphene, changes in the shape of fullerene and the distance of fullerene to graphene in these structures were determined.