Regensburg 2010 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 52: Graphene II
O 52.6: Vortrag
Mittwoch, 24. März 2010, 16:15–16:30, H31
X-ray absorption and magnetic circular dichroism of graphene/Ni(111) — Martin Weser1, Yvonne Rehder1, Karsten Horn1, Muriel Sicot2, Mikhail Fonin2, Aleksej Preobrajenski3, Elena Voloshina4, and •Yuriy Dedkov1 — 1Fritz-Haber Institut der Max-Planck Gesellschaft, Berlin, Germany — 2Universität Konstanz, Germany — 3MAX-lab, Lund, Sweden — 4Freie Universität Berlin, Germany
A long electronic mean free path and negligible spin-orbit coupling in graphene render this material ideal for applications based on ballistic transport like the spin filed effect transistor and the perfect spin-filtering device. The model system, graphene/Ni(111), is of special interest, providing an ideal interface between graphene and ferromagnetic material, from a structural point of view. Here we present the studies of the electronic and magnetic properties of the lattice-matched graphene/Ni(111) interface which were performed by means of angle-resolved x-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD) at the Ni L2,3 and C K absorption edges. The XAS C 1s→ π*, σ* spectra show pronounced changes as the angle, α, between the electrical vector of the light and surface normal is varied, reflecting the symmetry of the final state. XMCD reveals an induced magnetic moment of the carbon atoms in the graphene layer aligned parallel to the Ni 3d magnetization. Our experimental results are discussed in the light of recent density-functional theory calculations and previous results on the observation of induced magnetism in non-magnetic materials. (See M. Weser et al., arXiv:0907.4344v1).