Single-layer graphene on epitaxial FeRh thin films

Graphene is a 2D material that displays excellent electronic transport properties with prospective applications in many fields. Inducing and controlling magnetism in the graphene layer, for instance by proximity of magnetic materials, may enable its utilization in spintronic devices. This paper presents fabrication and detailed characterization of single-layer graphene formed on the surface of epitaxial FeRh thin films. The magnetic state of the FeRh surface can be controlled by temperature, magnetic field or strain due to interconnected order parameters. Characterization of graphene layers by X-ray Photoemission and X-ray Absorption Spectroscopy, Low-Energy Ion Scattering, Scanning Tunneling Microscopy, and Low-Energy Electron Microscopy shows that graphene is single-layer, polycrystalline and covers more than 97% of the substrate. Graphene displays several preferential orientations on the FeRh(0 0 1) surface with unit vectors of graphene rotated by 30°, 15°, 11°, and 19° with respect to FeRh substrate unit vectors. In addition, the graphene layer is capable to protect the films from oxidation when exposed to air for several months. Therefore, it can be also used as a protective layer during fabrication of magnetic elements or as an atomically thin spacer, which enables incorporation of switchable magnetic layers within stacks of 2D materials in advanced devices.We thank Prof. Peter Varga for discussion on the graphene domain contrast in STM. V.U. and J.A.A. acknowledge the Grant Agency of the Czech Republic (grant no. 16-23940Y). Access to the CEITEC Nano Research Infrastructure was supported by the Ministry of Education, Youth and Sports (MEYS) of the Czech Republic under the projects CEITEC 2020 (LQ1601) and CzechNanoLab (LM2018110). P.P. and J.C. acknowledge the project TC17021 of the Inter-Excellence program of MEYS. S.P., M.P. and T.S. acknowledge the support from the H2020 Twinning program (project SINNCE, 810626) and Technology Agency of the Czech Republic (grant No. TE01020233). V.U. was supported by funding from the European Union's Horizon 2020 research and innovation program under the Marie Skłodowska-Curie that is co-financed by the South Moravian Region under grant agreement No. 665860. This project has received funding from the EU-H2020 research and innovation program under grant agreement No 654360 having benefitted from the access provided by CNRS to the SOLEIL Synchrotron, within the framework of the "NFFA-Europe Transnational Access Activity"