The magic-sized carbon clusters on the transition metal surfaces with a four-fold symmetry

Abstract

In order to understand the metal surface type dependent graphene chemical vapor deposition (CVD) growth, we have systematically explored the structural evolution of carbon clusters on Cu(100) substrate by using density functional theory (DFT) calculation. It is revealed that the most stable carbon clusters, Cn (n = 1–32), experience a structural transition from linear sp1 atom chain to sp2 2D network at a critical cluster size of n = 13. The highly stable sp2 network structures on a Cu(100) facet are mostly in a rectangular shape as the interplay between the C6v symmetry of graphene and the C4v symmetry of the Cu(100) surface leads to a C2v symmetry of the whole system. A few carbon clusters, C14, C20, C24 and C28, which all possesses the C2v symmetry are highly stable and possess the feature of magic sized clusters. Among them, C28 was found to have superior stability in a very large size range and are expected to be observed on various transition metal surfaces. Our study shows that graphene nucleation on a transition metal surface depends on surface type and symmetry dependent, which offers a theoretical guidance for the controllable CVD growth of graphene and graphene quantum dotes.