Interdependence between training and magnetization reversal in granular Co-CoO exchange bias systems
Menéndez Dalmau, Enric (KU Leuven. Instituut voor Kern- en Stralingsfysica)
Dias, T. (KU Leuven. Instituut voor Kern- en Stralingsfysica)
Geshev, Julian (Instituto de Física, Universidade Federal Do Rio Grande Do sul (UFRGS))
López-Barbera, José Francisco (Institut Català de Nanociència i Nanotecnologia)
Nogués, Josep (Institut Català de Nanociència i Nanotecnologia)
Steitz, Roland (Helmholtz-Zentrum Berlin für Materialien und Energie GmbH)
Kirby, Brian (Brian J.) (National Institute of Standards and Technology (Gaithersburg, Estats Units d'Amèrica))
Borchers, J. A. (National Institute of Standards and Technology (Gaithersburg, Estats Units d'Amèrica))
Pereira, L. M. C. (KU Leuven. Instituut voor Kern- en Stralingsfysica)
Vantomme, André (KU Leuven, Instituut voor Kern- en Stralingsfysica)
Temst, Kristiaan (KU Leuven, Instituut voor Kern- en Stralingsfysica)

Date:	2014
Abstract:	The interdependence between training and magnetization reversal in granular Co-CoO exchange bias (EB) systems prepared by O ion implantation in Co thin films is demonstrated by polarized neutron reflectometry. While high-fluence O-implanted thin films show reduced relative training values and no asymmetry in magnetization reversal (all reversals take place by domain wall nucleation and motion), low-fluence O ion implantation results in an increased relative training and a magnetization reversal asymmetry between the first descending and the first ascending branches. Whereas the untrained decreasing field reversal occurs mainly by domain wall nucleation and motion, traces of a domain rotation contribution are evidenced in the increasing field reversal. This is explained by the evolution of the CoO structure and the contribution of the out-of-plane magnetization with ion implantation. The amount of incorporated O, which determines the threshold between both behaviors, is around 20 at. %. This reveals that the interdependence between training and magnetization reversal is insensitive to the morphology of the constituents (i. e. , granular or layered), indicating that this is an intrinsic EB effect, which can be conveniently tailored by the interplay between the intrinsic properties of the investigated materials and ion implantation.
Grants:	European Commission 283883 Ministerio de Economía y Competitividad MAT2010-20616-C02 Agència de Gestió d'Ajuts Universitaris i de Recerca 2009/SGR-1292
Rights:	Tots els drets reservats.
Language:	Anglès
Document:	Article ; recerca ; Versió sotmesa a revisió
Published in:	Physical review B : Condensed matter and materials physics, Vol. 89, issue 14 (Sep. 2014) , art. 144407, ISSN 1550-235X

DOI: 10.1103/PhysRevB.89.144407

Preprint 22 p, 1.1 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