Enhanced Magnetism through Oxygenation of FePc/Ag(110) Monolayer Phases
Bartolome, Elena (Escola Universitària Salesiana de Sarrià)
Bartolomé, Juan (Instituto de Ciencia de Materiales de Aragón)
Sedona, Francesco (Università Degli Studi di Padova. Dipartimento di Scienze Chimiche)
Lobo-Checa, Jorge (Instituto de Ciencia de Materiales de Aragón)
Forrer, Daniel (Università Degli Studi di Padova. Dipartimento di Scienze Chimiche)
Herrero-Albillos, Julia (Centro Universitario de la Defensa)
Piantek, Marten (Instituto de Nanociencia de Aragón)
Herrero-Martín, Javier (ALBA Laboratori de Llum de Sincrotró)
Betto, Davide (European Synchrotron Radiation Facility)
Velez-Fort, Emilio (European Synchrotron Radiation Facility)
García, L. M. (Instituto de Ciencia de Materiales de Aragón)
Panighel, Mirco (TASC IOM-CNR)
Mugarza, Aitor (Institut Català de Nanociència i Nanotecnologia)
Sambi, Mauro (Università Degli Studi di Padova. Dipartimento di Scienze Chimiche)
Bartolomé, Fernando (Instituto de Ciencia de Materiales de Aragón)

Data:	2020
Resum:	Iron phthalocyanines (FePc) adsorbed onto a Ag(110) substrate self-assemble into different monolayer phases going from rectangular to different oblique phases, with increasing molecular density. We have investigated the oxygen uptake capability of the different phases and their associated magneto-structural changes. Our study combines scanning tunneling microscopy and spectroscopy (STM/STS), X-ray magnetic circular dichroism (XMCD), and density functional theory (DFT) calculations. STM measurements reveal that the oxygenation reaction of the FePc/Ag(110) generally involves a displacement and a rotation of the molecules, which affects the electronic state of the Fe centers. The oxygen intercalation between FePc and the substrate is greatly obstructed by the steric hindrance in the high-density phases, to the point that a fraction of oblique phase molecules cannot change their position after oxidizing. Depending on the oxidation state and adsoption geometry, the STS spectra show clear differences in the Fe local density of states, which are mirrored in the XAS and XMCD experiments. Particularly, XMCD spectra of the oxidized phases reflect the distribution of FePc species (nonoxygenated, oxygenated-rotated, and oxygenated-unrotated) in the different cases. Sum rule analysis yields the effective spin (mseff) and orbital (mL) magnetic moments of Fe in the different FePc species. Upon oxygenation, the magnetic moment of FePc molecules increases about an order of magnitude, reaching mTOT ∼2. 2 μB per Fe atom.
Ajuts:	Ministerio de Economía y Competitividad MAT2017-83468-R Ministerio de Economía y Competitividad SEV-2017-0706
Drets:	Tots els drets reservats.
Llengua:	Anglès
Document:	Article ; recerca ; Versió sotmesa a revisió
Matèria:	Iron phthalocyanines ; Local density of state ; Molecular density ; Oxygen intercalation ; Phase molecules ; Scanning tunneling microscopy and spectroscopy ; Steric hindrances ; X-ray magnetic circular dichroism
Publicat a:	Journal of physical chemistry. C, Vol. 124, issue 25 (June 2020) , p. 13993-14006, ISSN 1932-7455

DOI: 10.1021/acs.jpcc.0c01988

Preprint 14 p, 2.3 MB

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Documents de recerca > Documents dels grups de recerca de la UAB > Centres i grups de recerca (producció científica) > Ciències > Institut Català de Nanociència i Nanotecnologia (ICN2)
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