Critical Films on Graphene Substrates*

When depositing a substance onto a surface, it follows that as one adds more of the substance, the thickness of the film formed on the surface will grow. However, a particle's ability to adsorb onto the surface is dependent on the interaction potential and geometry. For atomically flat two-dimensional materials such as graphene, it is predicted that the interactions between the graphene sheet and light atoms in a nearby gas are so weak that film growth may become arrested at a critical thickness. We report on molecular dynamics simulations of nitrogen near graphene to explore the existence and properties of the predicted critical film and investigate the role of temperature and pressure during the adsorption process.