Structure and magnetism of ultrathin nickel-iron oxides grown on Ru(0001) by high-temperature oxygen-assisted molecular beam epitaxy
Mandziak, Anna (ALBA Laboratori de Llum de Sincrotró)
Figuera, Juan de la (Instituto de Química Física "Rocasolano")
Ruiz-Gómez, Sandra (Universidad Complutense de Madrid. Departamento de Física de Materiales)
Soria, Guiomar D. (Instituto de Química Física "Rocasolano")
Pérez, Lucas (Instituto Madrileño de Estudios Avanzados en Nanociencia)
Prieto Recio, Pilar (Universidad Autónoma de Madrid. Departamento de Física Aplicada)
Quesada, Adrian (Instituto de Cerámica y Vidrio (CSIC))
Foerster, Michael (ALBA Laboratori de Llum de Sincrotró)
Aballe, Lucía (ALBA Laboratori de Llum de Sincrotró)

Date:	2018
Abstract:	We demonstrate the preparation of ultrathin Fe-rich nickel ferrite (NFO) islands on a metal substrate. Their nucleation and growth are followed in situ by low-energy electron microscopy (LEEM). A comprehensive characterization is performed combining LEEM for structural characterization and PEEM (PhotoEmission Electron Microscopy) with synchrotron radiation for chemical and magnetic analysis via X-ray Absorption Spectroscopy and X-ray Magnetic Circular Dichroism (XAS-PEEM and XMCD-PEEM, respectively). The growth by oxygen-assisted molecular beam epitaxy takes place in two stages. First, islands with the rocksalt structure nucleate and grow until they completely cover the substrate surface. Later three-dimensional islands of spinel phase grow on top of the wetting layer. Only the spinel islands show ferromagnetic contrast, with the same domains being observed in the Fe and Ni XMCD images. The estimated magnetic moments of Fe and Ni close to the islands surface indicate a possible role of the bi-phase reconstruction. A significant out-of-plane magnetization component was detected by means of XMCD-PEEM vector maps.
Grants:	Ministerio de Economía y Competitividad MAT2014-52477-C5-2-P Ministerio de Economía y Competitividad MAT2015-64110-C2-1-P Ministerio de Economía y Competitividad MAT2015-64110-C2-2-P European Commission 720853
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Published in:	Scientific reports, Vol. 8 (December 2018) , art. 17980, ISSN 2045-2322

DOI: 10.1038/s41598-018-36356-6
PMID: 30568169

8 p, 2.0 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > The ALBA Synchrotron
Articles > Research articles
Articles > Published articles