Air-Protected Epitaxial Graphene/Ferromagnet Hybrids Prepared by Chemical Vapor Deposition and Intercalation

The extended carbon-metal contact in graphene-metal hybrids opens new avenues for manipulating the properties of both constituents of the hybrid and for combining the functionalities of each of them. We developed a two-step ultrahigh vacuum route to fabricate high-quality nanometer-thick metal films having abrupt interfaces, sandwiched between a protective graphene layer and its substrate, using chemical vapor deposition and metal intercalation made effective at mild temperatures. We demonstrate functional hybrid systems with ferromagnetic metal films whose topmost graphene interface allows us to manipulate the direction of the magnetization of the film to a large extent. We obtain prominently perpendicular magnetization for a large range of Co thickness. The preparation and properties of the graphene/ferromagnet hybrid are analyzed using a set of surface-sensitive in situ and ex situ techniques together with first-principles calculations, altogether providing extensive topographic, chemical, magnetic, and vibrational characterization.