Spin enhancement and band gap opening of ferrimagnetic graphene on fcc-Co(111) surface upon hydrogenation

Abstract

Using density functional theory we show that the diamagnetic graphene sheet becomes ferrimagnetic with net magnetic moment of −0.021 μB when adsorbed on Co (111). Upon hydrogenating the graphene sheet with 0.5 ML coverage, the magnetic moment of the ferrimagnetic graphene increased by six-fold. The band gap of the hydrogenated graphene sheet is also significantly enhanced. We attribute the reason behind the increase of magnetic moment to the localization of the π electron cloud on the nonhydrogenated carbon atom.