Structural, chemical, and magnetic properties of cobalt intercalated graphene on silicon carbide.

Author(s) Hönig, R.; Roese, P.; Shamout, K.; Ohkochi, T.; Berges, U.; Westphal, C.
Journal Nanotechnology
Date Published 2019 Jan 11

We report on a study of the Co intercalation process underneath the R30° reconstructed 6H-SiC(0001) surface for Co film-thicknesses in a range of 0.4-12 nm using a combination of surface sensitive imaging, diffractive, and spectroscopic methods. In situ photoemission electron microscopy reveals a dependence of the intercalation temperature on the Co film-thickness. Using low energy electron diffraction and photoemission spectroscopy (XPS), we find that the SiC surface reconstruction is partially lifted and transformed. We show that the R30° reconstruction does not prevent silicide formation for Co film-thicknesses  ≥0.4 nm according to XPS and x-ray absorption spectra. Our results indicate that the silicide formation is self-limited to a thin interface region and is followed by Co intercalation between graphene and silicide. Furthermore, we analyze the magnetic properties using x-ray magnetic circular dichroism at the Co L-edge. In-plane magnetization is observed for all analyzed film-thicknesses. For ultra-thin Co films, self-assembled magnetic wires with a width of the order of 100 nm form at the step-edges.

DOI 10.1088/1361-6528/aae8c9
ISSN 1361-6528
Citation Nanotechnology. 2019;30(2):025702.

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