Thesis defense of Christine Jansing

In this work, graphene/metal multilayer systems are investigated by means of polarizationdependent spectroscopy at the C 1s edge. Absorption, reflection, and polarimetry measurements using synchrotron radiation provide information on the electronic structure, the orientation of unoccupied states, the bonding behavior of graphene on metallic substrates, and magnetic contributions of carbon on ferromagnetic substrates.
Since measurements in this energy range are sensitive to carbon contamination on beamline optics, higher-order light contributions, and saturation effects in TEY, two correction procedures are developed: one for reflection spectra and one for TEY data. This makes it possible to extract optical constants in the resonance region from the corrected data.
The results show that, in complex multilayer systems, absorption-based observables are generally better suited than reflection-based observables for assessing hybridization and decoupling. Magnetooptical measurements further show that the magnetic response of graphene on ferromagnetic substrates is predominantly coupled to states of  character. In addition, it is investigated which conclusions regarding orientation, coupling strength, and the influence of gold intercalation can be drawn from the combined analysis of polarimetry, TEY, and reflection spectra. Furthermore, the optical constants of HOPG and of graphene decoupled by gold intercalation, as well as the magnetooptical constants of strongly hybridized graphene on cobalt, are determined.