Study of graphene on Ir(111) by X-ray photoelectron spectroscopy and diffraction

Full text: Graphene has a whole set of fascinating properties like high mobility of relativistic charge carriers, ballistic transport, high mechanical strength, and ideal surface to mass ratio. An alternative system that allows the study of these properties is quasi-free-standing graphene, i.e. graphene that preserves its properties even when it is supported by a substrate. Recent studies could demonstrate that Ir(111) does indeed allow for the preparation of extended graphene with high structural quality, and the band structure of graphene on Ir(111) is almost identical to the one of pristine graphene. Metal intercalation between graphene and different substrates has been intensively used either to functionalize the electronic properties of graphene or to enhance the physical-chemical properties of the intercalating metal. The aim of this work is determine the structure of graphene on Ir(111) and Fe intercalation between epitaxial graphene and the Ir(111) substrate by X-ray photoelectron spectroscopy (XPS) and diffraction (XPD). The XPS and XPD experiments were carried out at the PGM beamline of LNLS and complementary STM measurements were performed at UNICAMP. The preliminary surface structure determination based in a comprehensive multiple scattering calculation approach will be presented. (author)