uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Nanoscale size effect on surface spin canting in iron oxide nanoparticles synthesized by the microemulsion method
Show others and affiliations
2012 (English)In: Journal of Physics D: Applied Physics, ISSN 0022-3727, E-ISSN 1361-6463, Vol. 45, no 19, 195001- p.Article in journal (Refereed) Published
Abstract [en]

Uniformly sized and crystalline iron oxide nanoparticles (IONPs) with spinel structure and mean diameters of about 3, 6 and 9 nm were synthesized in high yield using the microemulsion route at room temperature. The nanoparticles (NPs) were stabilized in situ by organic surfactant molecules which acted both as a stabilizer of the microemulsion system and as a capping layer of the NP surface. NP size control was attained by careful adjustment of the preparation conditions. The structure, morphology and NP size distribution were investigated by x-ray diffraction, transmission electron microscopy and scanning electron microscopy. A particular effort was devoted in this work to study the effect of size and capping of these NPs on their magnetic structure by in-field Mossbauer spectroscopy at 4.2 K. The mean canting angle (relative to the applied field direction) of the Fe spins was observed to increase with decreasing NP size due to the enhanced surface-to-volume ratio. Comparing bare and capped NPs of the same diameter, we verified that the spin canting was not affected by the organic capping. This implied almost identical magnetic orientations of bare and capped NPs. Simultaneously, the capping material was capable of preventing agglomeration effects which can occur in case of direct particle contact. Using a core/shell model, we showed that spin canting originated from the surface shell of the NPs. Furthermore, the Mossbauer spectral parameters provided evidence for the existence of a high fraction of Fe3O4 (magnetite) in the IONP.

Place, publisher, year, edition, pages
2012. Vol. 45, no 19, 195001- p.
National Category
Physical Sciences
URN: urn:nbn:se:uu:diva-174901DOI: 10.1088/0022-3727/45/19/195001ISI: 000303536500001OAI: oai:DiVA.org:uu-174901DiVA: diva2:529534
Available from: 2012-05-30 Created: 2012-05-30 Last updated: 2012-05-30Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Sanyal, Biplab
By organisation
Materials Theory
In the same journal
Journal of Physics D: Applied Physics
Physical Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 180 hits
ReferencesLink to record
Permanent link

Direct link