Coupling of a carbon nanotube and graphene nanoribbon by titanium and vanadium chains: a first-principles study

We find that the structure consisting of an armchair single-walled carbon nanotube deposited on a graphene nanoribbon is greatly strengthened by the further adsorption of titanium or vanadium chains. Density functional calculations show that the nanotube and nanoribbon are firmly glued together by the atomic chain introduced between them. The binding energy depends on the type of the atomic chain used, the stacked configuration, and the binding location. Band structures reveal strong hybridization between the 3d orbitals of the transition metals and 2p orbitals of the carbon atoms. For titanium adsorption at the ribbon center, the chain is non-magnetic while the ribbon remains antiferromagnetic. For adsorption at the edge, however, magnetism totally disappears at the coupling side. Magnetism for vanadium chain adsorption is even more complicated. The results point to a new way for synthesizing nanowires and possible application in robust nanoelectronic circuits.