Structure and magnetism of Tm atoms and monolayers on W(110)
Nistor, Corneliu (Institut Català de Nanociència i Nanotecnologia)
Mugarza, Aitor (Institut Català de Nanociència i Nanotecnologia)
Stepanow, Sebastian (ETH Zürich. Department of Materials)
Gambardella, Pietro (Institut Català de Nanociència i Nanotecnologia)
Kummer, Kurt (European Synchrotron Radiation Facility)
Diez-Ferrer, José Luis (Universidad de Zaragoza. Laboratorio de Microscopias Avanzadas)
Coffey, David (Instituto de Ciencia de Materiales de Aragón)
De La Fuente, César (Instituto de Ciencia de Materiales de Aragón)
Ciria, Miguel (Universidad de Zaragoza. Departamento de Física de la Materia Condensada)
Arnaudas, José Ignacio (Universidad de Zaragoza. Departamento de Física de la Materia Condensada)

Date:	2014
Abstract:	We investigated the growth and magnetic properties of Tm atoms and monolayers deposited on a W(110) surface using scanning tunneling microscopy and x-ray magnetic circular and linear dichroism. The equilibrium structure of Tm monolayer films is found to be a strongly distorted hexagonal lattice with a Moiré pattern due to the overlap with the rectangular W(110) substrate. Monolayer as well as isolated Tm adatoms on W present a trivalent ground-state electronic configuration, contrary to divalent gas phase Tm and weakly coordinated atoms in quench-condensed Tm films. Ligand field multiplet simulations of the x-ray absorption spectra further show that Tm has a $j =6,Jz=±4 and $j =6,Jz=±5 electronic ground state separated by a few meV from the next lowest substates $j =6,Jz=±6. Accordingly, both the Tm atoms and monolayer films exhibit large spin and orbital moments with out-of-plane uniaxial magnetic anisotropy. X-ray magnetic dichroism measurements as a function of temperature show that the Tm monolayers develop antiferromagnetic correlations at about 50 K. The triangular structure of the Tm lattice suggests the presence of significant magnetic frustration in this system, which may lead to either a noncollinear staggered spin structure or intrinsic disorder.
Grants:	European Commission 203239 Ministerio de Economía y Competitividad MAT2009-10040 Ministerio de Ciencia e Innovación MAT2010-15659 Ministerio de Ciencia e Innovación MAT2012-31309 Agència de Gestió d'Ajuts Universitaris i de Recerca 2009/SGR-695
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Language:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Published in:	Physical review B : Condensed matter and materials physics, Vol. 90, issue 6 (Aug. 2014) , art. 64423, ISSN 1550-235X

DOI: 10.1103/PhysRevB.90.064423

Postprint 10 p, 4.8 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles