Regensburg 2016 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 9: Graphene: Structure and Dynamics
(Joint session of DS, DY, HL, MA, O and TT organized by O)
TT 9.6: Talk
Monday, March 7, 2016, 12:00–12:15, H24
Electronic properties of ytterbium interaction with graphene on Ir(111) — Hendrik Vita1, •Stefan Böttcher2, and Karsten Horn1 — 1Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany — 2SPECS Surface Nano Analysis GmbH, Berlin, Germany
The intercalation of metals in between graphene monolayers and a substrate is interesting from several points of view, for example in order to understand the effect of symmetry lowering in the interaction of the metal states with the specific graphene π bands in the region of the “Dirac cone”. Here we present a study of the intercalation of a rare earth metal, Yb, in between graphene and Ir(111). Ytterbium exhibits an s-type valence band, making it possible to compare the electronic structure to the widely studied cases of alkali metals used as intercalates in graphene intercalation compounds. Using core level spectroscopy we follow the deposition of Yb and the evolution of the intercalated phase. LEED studies show that the structural arrangement of the intercalated Yb thin film leads to a (√3 × √3) R 30∘ phase. Angle-resolved photoemission reveals that the interaction between the metal states and the graphene π band near the K point induces an extremely strong n-type doping. Hybridization-induced band gaps open in the π band at binding energies of 0.3 eV and 1.6 eV due to the interaction with the strongly localized metal 4 f states. We compare our data with other weakly and strongly interacting intercalated metal layers.