Tunable high-field magnetization in strongly exchange-coupled freestanding Co/CoO core/shell coaxial nanowires
Salazar-Alvarez, German (Stockholm University. Department of Materials and Environmental Chemistry)
Geshev, Julian (Universitat Autònoma de Barcelona. Departament de Física)
Agramut Puig, Sebastià (Universitat Autònoma de Barcelona. Departament de Física)
Navau Ros, Carles (Universitat Autònoma de Barcelona. Departament de Física)
Sánchez Moreno, Álvaro (Universitat Autònoma de Barcelona. Departament de Física)
Sort Viñas, Jordi (Universitat Autònoma de Barcelona. Departament de Física)
Nogués, Josep (Institut Català de Nanociència i Nanotecnologia)

Date:	2016
Abstract:	The exchange bias properties of Co/CoO coaxial core/shell nanowires have been investigated with cooling and applied fields perpendicular to the wire axis. This configuration leads to unexpected exchange-bias effects. Firstly, the magnetization value at high fields is found to depend on the field-cooling conditions. This effect arises from the competition between the magnetic anisotropy and the Zeeman energies for cooling fields perpendicular to the wire axis. This allows imprinting pre-defined magnetization states to the AFM, as corroborated by micromagnetic simulations. Secondly, the system exhibits a high-field magnetic irreversibility, leading to open hysteresis loops, attributed to the AFM easy-axis reorientation during the reversal (effect similar to athermal training). A distinct way to manipulate the high-field magnetization in exchange-biased systems, beyond the archetypical effects, is thus experimentally and theoretically demonstrated.
Grants:	European Commission 296679 Ministerio de Economía y Competitividad SEV-2013-0295 Ministerio de Economía y Competitividad MAT2012-35370 Agència de Gestió d'Ajuts Universitaris i de Recerca 2014/SGR-1015 Agència de Gestió d'Ajuts Universitaris i de Recerca 2014-SGR-150
Rights:	Tots els drets reservats.
Language:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Subject:	Coaxial nanowires ; Exchange bias ; CoO ; Uncopmpensated spins ; Training effects ; High field irreversibility
Published in:	ACS applied materials & interfaces, Vol. 8 núm 34 (Agost 2016) , p. 22477-22483, ISSN 1944-8252

DOI: 10.1021/acsami.6b05588

Post-print 25 p, 524.2 KB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Group of Smart Nanoengineered Materials, Nanomechanics and Nanomagnetism (Gnm3)
Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
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Articles > Published articles