Effect of applied force and atomic organization of copper on its adhesion to a graphene substrate

Copper/graphene composites are lightweight and possess many attractive properties such as improved mechanical, electrical, and thermal properties. The organization of copper atoms at the copper/graphene interface highly influences the abovementioned properties. In this study, the organization of copper atoms and applied force-induced desorption of copper from a graphene substrate were studied via molecular dynamics (MD) simulation. The copper atoms were organized in face-centred cubic (fcc) and hexagonal close-packed (hcp) lattices over the graphene substrate. However, at the copper/graphene interface, copper atoms were organized in the {111} facet of the fcc lattice. The applied force-induced desorption of copper atoms from a graphene substrate was studied at high temperature (T = 1000 K). A critical force was required to be exceeded before the detachment of copper atoms from the substrate. It was found that a higher critical force was required to remove copper atoms from the graphene substrate in the z-direction (perpendicular to the substrate) compared to that in the x-direction. The outcome of this study may provide useful scientific information about the metal/graphene interface properties, which will help enhance the performance of graphene-based metallic nanocomposites.