Electronic structure of graphene/Co interfaces

D. Pacilé, S. Lisi, I. Di Bernardo, M. Papagno, L. Ferrari, M. Pisarra, M. Caputo, S. K. Mahatha, P. M. Sheverdyaeva, P. Moras, P. Lacovig, S. Lizzit, A. Baraldi, M. G. Betti, C. Carbone

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Abstract

Photoemission, from core levels and valence band, and low-energy electron diffraction (LEED) have been employed to investigate the electronic and structural properties of graphene-ferromagnetic (G-FM) systems, obtained by intercalation of one monolayer (1 ML) and several layers (4 ML) of Co on G grown on Ir(111). Upon intercalation of 1 ML of Co, the Co lattice is resized to match the Ir-Ir lattice parameter, resulting in a mismatched G/Co/Ir(111) system. The intercalation of further Co layers leads to a relaxation of the Co lattice and a progressive formation of a commensurate G layer lying on top. We show the C 1s line shape and the band structure of G in the two artificial phases, mismatched and commensurate G/Co, through a comparison with the electronic structure of G grown directly on a Co thick film. Our results show that while the G valence band mainly reflects the hybridization with the d states of Co, regardless of the structural phase, the C 1s line shape is very sensitive to the rumpling of the G layer and the coordination of carbon atoms with the underlying Co. Even in the commensurate (1×1) G/Co phase, where graphene is in register with the Co film, from the angular dependence of the C 1s core level we infer the presence of more than a single component, due to inequivalent adsorption sites of carbon sublattices.

Original languageEnglish
Article number195446
Number of pages6
JournalPhysical Review B
Volume90
Issue number19
DOIs
Publication statusPublished - 26 Nov 2014
Externally publishedYes

Cite this

Pacilé, D., Lisi, S., Di Bernardo, I., Papagno, M., Ferrari, L., Pisarra, M., Caputo, M., Mahatha, S. K., Sheverdyaeva, P. M., Moras, P., Lacovig, P., Lizzit, S., Baraldi, A., Betti, M. G., & Carbone, C. (2014). Electronic structure of graphene/Co interfaces. Physical Review B, 90(19), [195446]. https://doi.org/10.1103/PhysRevB.90.195446