Berlin 2018 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

O: Fachverband Oberflächenphysik

O 15: Graphen: Adsorption, intercalation and doping I (joint session O/TT)

O 15.5: Vortrag

Montag, 12. März 2018, 16:00–16:15, MA 043

Decoupling of the graphene/ferromagnet interface by gold intercalation: Effect on optical constants — •Christine Jansing¹, Hans-Christoph Mertins¹, Markus Gilbert¹, Maxim Krivenkov², Andrei Varykhalov², Oliver Rader², Andreas Gaupp², Andrey Sokolov², Hud Wahab³, Heiko Timmers³, Dominik Legut⁴, and Peter M. Oppeneer⁵ — ¹Münster University of Applied Sciences, Stegerwaldstr. 39, D-48565 Steinfurt — ²Helmholtz-Zentrum Berlin für Materialien und Energie, Albert Einstein Str. 15, D-12489 Berlin — ³University of New South Wales, Canberra, ACT 2600, Australia — ⁴IT4Innovations Center, VSB-Technical University of Ostrava, CZ-708 33 Ostrava, Czech Republic — ⁵Department of Physics and Astronomy, Uppsala University, S-75120 Uppsala, Sweden

X-ray absorption and reflectance spectroscopy of linearly polarized synchrotron radiation across the carbon 1s edge of graphene/Co/W and graphene/Ni/W is utilized to investigate the effect of gold intercalation on the complex optical constants of these systems. The p_z-orbitals of graphene hybridize strongly with the 3d states of the ferromagnetic substrate. Hybridization effects can be reduced by intercalation of gold which also leads to a change in the optical constants. A complete set of optical constants was determined, describing the π*- and σ*- resonances of graphene. The absorption index k was directly deduced from the measured absorption spectra whereas the refractive index n has been extracted from k via a Kramers-Kronig transformation. Based on these optical constants reflection spectra have been simulated that are in good agreement with our experimental data.