Regensburg 2016 – scientific programme
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O: Fachverband Oberflächenphysik
O 61: Graphene II: Adsorption, Intercalation and Doping
O 61.1: Talk
Wednesday, March 9, 2016, 15:00–15:15, S053
H atom scattering from epitaxial graphene on Pt(111) — •Hongyan Jiang1, Yvonne Dorenkamp1, Alec Wodtke1,2,3, and Oliver Buenermann1,2,3 — 1Institute for Physical Chemistry, Georg-August University of Goettingen, Goettingen, Germany — 2Department of Dynamics at Surfaces, Max Planck Institute for Biophysical Chemistry, Goettingen, Germany — 3International Center for Advanced Studies of Energy Conversion, Georg-August University of Goettingen, Goettingen, Germany
Adsorption of hydrogen atoms on graphene is playing an important role in hydrogen storage, graphene based electronics, nuclear fusion and interstellar chemistry. The interaction of hydrogen atoms with graphene is studied in a newly built atom-surface scattering machine. A nearly mono-energetic hydrogen atom beam is formed by laser photolysis. The hydrogen atoms are scattered from a well-defined sample held in UHV. The scattered hydrogen atoms are detected using Rydberg-atom neutral time-of-flight. This technique allows us to record angle resolved, high resolution energy loss spectra of scatted hydrogen atoms. Scattering of hydrogen atoms from epitaxial graphene on Pt(111) shows a very different behavior than scattering from clean Pt(111). For low incidence kinetic energy, graphene acts like an atomic mirror. We observe narrow scattering angle and kinetic energy distribution and small translational energy loss. For high incidence kinetic energy, broad distribution and large translational energy loss is observed. The process obeys normal energy scaling. We speculate that this behavior is connected to the barrier of hydrogen atom adsorption on graphene.