Magnetic anisotropy and magnetization dynamics of Fe nanoparticles embedded in Cr and Ag matrices
2015 (English)In: Philosophical Magazine, ISSN 1478-6435, E-ISSN 1478-6443, Vol. 95, no 33, 3798-3807 p.Article in journal (Refereed) Published
Static and dynamical magnetic properties of Fe nanoparticles (NPs) embedded in non-magnetic (Ag) and antiferromagnetic (Cr) matrices with a volume filling fraction (VFF) of 10% have been investigated. In both Fe@Ag and Fe@Cr nanocomposites, the Fe NPs have a narrow size distribution, with a mean particle diameter around 2nm. In both samples, the saturation magnetization reaches that of Fe bulk bcc, suggesting the absence of alloying with the matrices. The coercivity at 5K is much larger in Fe@Cr than in Fe@Ag as a result of the strong interaction between the Fe NPs and the Cr matrix. Temperature-dependent magnetization and ac-susceptibility measurements point out further evidence of the enhanced interparticle interaction in the Fe@Cr system. While the behaviour of Fe@Ag indicates the presence of weakly interacting magnetic monodomain particles with a wide distribution of blocking temperatures, Fe@Cr behaves like a superspin glass produced by the magnetic interactions between NPs.
Place, publisher, year, edition, pages
2015. Vol. 95, no 33, 3798-3807 p.
magnetic nanoparticles, nanocomposites, nanomagnetism, exchange bias
Condensed Matter Physics Materials Engineering
IdentifiersURN: urn:nbn:se:uu:diva-268396DOI: 10.1080/14786435.2015.1090640ISI: 000364335800007OAI: oai:DiVA.org:uu-268396DiVA: diva2:878530
FunderSwedish Research CouncilGöran Gustafsson Foundation for promotion of scientific research at Uppala University and Royal Institute of Technology