Universität zu Köln

Huttmann, Felix, Klar, David, Atodiresei, Nicolae ORCID: 0000-0002-8203-1227, Schmitz-Antoniak, Carolin ORCID: 0000-0002-8450-3515, Smekhova, Alevtina, Martinez-Galera, Antonio J., Caciuc, Vasile, Bihlmayer, Gustav ORCID: 0000-0002-6615-1122, Bluegel, Stefan, Michely, Thomas ORCID: 0000-0003-1657-1847 and Wende, Heiko ORCID: 0000-0001-8395-3541 (2017). Magnetism in a graphene-4 f-3d hybrid system. Phys. Rev. B, 95 (7). COLLEGE PK: AMER PHYSICAL SOC. ISSN 2469-9969

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Abstract

We create an interface of graphene with a metallic and magnetic support that leaves its electronic structure largely intact. This is achieved by exposing epitaxial graphene on ferromagnetic thin films of Co and Ni to vapor of the rare earth metal Eu at elevated temperatures, resulting in the intercalation of an Eu monolayer in between graphene and its substrate. The system is atomically well defined, with the Eu monolayer forming a (root 3x root 3)R30 degrees superstructure with respect to the graphene lattice. Thereby, we avoid the strong hybridization with the (Ni, Co) substrate 3d states that otherwise drastically modify the electronic structure of graphene. This picture is suggested by our x-ray absorption spectroscopy measurements which show that after Eu intercalation the empty 2p states of C atoms resemble more the ones measured for graphite in contrast to graphene directly bound to 3d ferromagnetic substrates. We use x-ray magnetic circular dichroism at the Co and Ni L-2,L-3 and Eu M-4,M-5 as an element-specific probe to investigate magnetism in these systems. An antiferromagnetic coupling between Eu and Co/Ni moments is found, which is so strong that a magnetic moment of the Eu layer can be detected at room temperature. Density functional theory calculations confirm the antiferromagnetic coupling and provide an atomic insight into the magnetic coupling mechanism.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Huttmann, Felix UNSPECIFIED UNSPECIFIED UNSPECIFIED Klar, David UNSPECIFIED UNSPECIFIED UNSPECIFIED Atodiresei, Nicolae UNSPECIFIED orcid.org/0000-0002-8203-1227 UNSPECIFIED Schmitz-Antoniak, Carolin UNSPECIFIED orcid.org/0000-0002-8450-3515 UNSPECIFIED Smekhova, Alevtina UNSPECIFIED UNSPECIFIED UNSPECIFIED Martinez-Galera, Antonio J. UNSPECIFIED UNSPECIFIED UNSPECIFIED Caciuc, Vasile UNSPECIFIED UNSPECIFIED UNSPECIFIED Bihlmayer, Gustav UNSPECIFIED orcid.org/0000-0002-6615-1122 UNSPECIFIED Bluegel, Stefan UNSPECIFIED UNSPECIFIED UNSPECIFIED Michely, Thomas UNSPECIFIED orcid.org/0000-0003-1657-1847 UNSPECIFIED Wende, Heiko UNSPECIFIED orcid.org/0000-0001-8395-3541 UNSPECIFIED
URN:	urn:nbn:de:hbz:38-239490
DOI:	10.1103/PhysRevB.95.075427
Journal or Publication Title:	Phys. Rev. B
Volume:	95
Number:	7
Date:	2017
Publisher:	AMER PHYSICAL SOC
Place of Publication:	COLLEGE PK
ISSN:	2469-9969
Language:	English
Faculty:	Faculty of Mathematics and Natural Sciences
Divisions:	Faculty of Mathematics and Natural Sciences > Department of Physics > Institute of Physics II
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language CIRCULAR-DICHROISM; EXCHANGE; METAL; INTERMETALLICS; TEMPERATURE; TRANSITION; NI(111); ENERGY Multiple languages Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter Multiple languages
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/23949