Spin tuning of electron-doped metal-phthalocyanine layers
Stepanow, Sebastian (ETH Zürich. Department of Materials)
Lodi Rizzini, Alberto (Institut Català de Nanociència i Nanotecnologia)
Krull, Cornelius (Institut Català de Nanociència i Nanotecnologia)
Kavich, Jerald (Institut Català de Nanociència i Nanotecnologia)
Cezar, Julio C. (European Synchrotron Radiation Facility)
Yakhou-Harris, Flora (European Synchrotron Radiation Facility)
Sheverdyaeva, Polina M. (Consiglio Nazionale Delle Ricerche (Itàlia). Istituto di Struttura della Materia)
Moras, Paolo (Consiglio Nazionale Delle Ricerche (Itàlia). Istituto di Struttura della Materia)
Carbone, Carlo (Consiglio Nazionale Delle Ricerche (Itàlia). Istituto di Struttura della Materia)
Ceballos, Gustavo (Institut Català de Nanociència i Nanotecnologia)
Mugarza, Aitor (Institut Català de Nanociència i Nanotecnologia)
Gambardella, Pietro (Institut Català de Nanociència i Nanotecnologia)

Date:	2014
Abstract:	The spin state of organic-based magnets at interfaces is to a great extent determined by the organic environment and the nature of the spin-carrying metal center, which is further subject to modifications by the adsorbate-substrate coupling. Direct chemical doping offers an additional route for tailoring the electronic and magnetic characteristics of molecular magnets. Here we present a systematic investigation of the effects of alkali metal doping on the charge state and crystal field of 3d metal ions in Cu, Ni, Fe, and Mn phthalocyanine (Pc) monolayers adsorbed on Ag. Combined X-ray absorption spectroscopy and ligand field multiplet calculations show that Cu(II), Ni(II), and Fe(II) ions reduce to Cu(I), Ni(I), and Fe(I) upon alkali metal adsorption, whereas Mn maintains its formal oxidation state. The strength of the crystal field at the Ni, Fe, and Mn sites is strongly reduced upon doping. The combined effect of these changes is that the magnetic moment of high- and low-spin ions such as Cu and Ni can be entirely turned off or on, respectively, whereas the magnetic configuration of MnPc can be changed from intermediate (3/2) to high (5/2) spin. In the case of FePc a 10-fold increase of the orbital magnetic moment accompanies charge transfer and a transition to a high-spin state.
Grants:	European Commission 203239 Ministerio de Ciencia e Innovación MAT2010-15659 Agència de Gestió d'Ajuts Universitaris i de Recerca 2009/SGR-695
Rights:	Tots els drets reservats.
Language:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Subject:	Adsorbate-substrate ; Alkali metal doping ; Alkali-metal adsorption ; Magnetic characteristic ; Magnetic configuration ; Molecular magnet ; Orbital magnetic moment ; Organic-based magnets ; Circular dichroism ; Electrons ; Indoles ; Metals, Alkali ; Metals, Heavy ; Microscopy, Scanning Tunneling ; Organometallic Compounds ; X-Ray Absorption Spectroscopy
Published in:	Journal of the American Chemical Society, Vol. 136, issue 14 (April 2014) , p. 5451-5459, ISSN 1520-5126

DOI: 10.1021/ja501204q

Postprint 11 p, 1.9 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