Robust antiferromagnetic coupling in hard-soft bi-magnetic core/shell nanoparticles
2013 (English)In: Nature Communications, ISSN 2041-1723, Vol. 4, Art.nr.-2960 p.Article in journal (Refereed) Published
The growing miniaturization demand of magnetic devices is fuelling the recent interest in bi-magnetic nanoparticles as ultimate small components. One of the main goals has been to reproduce practical magnetic properties observed so far in layered systems. In this context, although useful effects such as exchange bias or spring magnets have been demonstrated in core/shell nanoparticles, other interesting key properties for devices remain elusive. Here we show a robust antiferromagnetic (AFM) coupling in core/shell nanoparticles which, in turn, leads to the foremost elucidation of positive exchange bias in bi-magnetic hard-soft systems and the remarkable regulation of the resonance field and amplitude. The AFM coupling in iron oxide-manganese oxide based, soft/hard and hard/soft, core/shell nanoparticles is demonstrated by magnetometry, ferromagnetic resonance and X-ray magnetic circular dichroism. Monte Carlo simulations prove the consistency of the AFM coupling. This unique coupling could give rise to more advanced applications of bi-magnetic core/shell nanoparticles.
Place, publisher, year, edition, pages
Nature Publishing Group, 2013. Vol. 4, Art.nr.-2960 p.
IdentifiersURN: urn:nbn:se:su:diva-100396DOI: 10.1038/ncomms3960ISI: 000329397500002OAI: oai:DiVA.org:su-100396DiVA: diva2:693110
Generalitat de Catalunya 2009-SGR-1292, 2009-SGR-35, 2010 PIV 00096;
Spanish Ministry of Science and Innovation (MICINN) MAT2010-20616-C02, MAT2011-27380-C02-01, MAT2010-16407, CSD2009-00013; ONDA of the European Union FP7-PEOPLE-2009-IRSES-247518; Russian grant RFBR-13-02-00121 14.B25.31.0025; U.S. Department of Energy DE-FG02-86ER45281; Knut and Alice Wallenberg Foundation 3DEM-NATUR; ICREA Academia award Spanish Ministry of Science and Innovation through the Juan de la Cierva Program; US Department of Energy, Office of Science, Office of Basic Energy Sciences DE-AC02-06CH11357; US Department of Energy (DOE), Basic Energy Sciences (BES), Materials Sciences and Engineering Division; ORNL's Shared Research Equipment (ShaRE) User Program; DOE-BES; STEMOX 739239; HSF-EU program ARISTEIA COMANA/22; US Department of Energy, Basic Energy Sciences and Experimental Condensed Matter Physics. 2014-02-032014-02-032014-02-03Bibliographically approved