<abstract xml:lang="en" xmlns="http://www.w3.org/1999/xhtml"><p>Two composites consisting of γ-Fe2O3 (maghemite) nanoparticles covered by two different oxygen-based free radicals derived from a 4-(methylamino)phenol sulphate and 8-hydroxy-1,3,6-trisulfonic trisodium salt acid were prepared and investigated by the magnetic resonance method in the 4–300 K range. Both composites displayed broad and very intense ferromagnetic resonance (FMR) lines originating from γ-Fe2O3 agglomerated nanoparticles. The FMR spectrum was fitted satisfactorily at each temperature by two Landau-Lifshitz functions reflecting the existence of magnetic anisotropy in the investigated system. The temperature dependence of the obtained FMR parameters (resonance field, linewidth, integrated intensity) was studied and the results were interpreted in terms of magnetic interactions between free radicals and nanoparticle agglomerates. A comparison with previously studied similar systems containing maghemite nanoparticles was made and conclusions about the role of free radicals were drawn.</p></abstract>

Two composites consisting of γ-Fe2O3 (maghemite) nanoparticles covered by two different oxygen-based free radicals derived from a 4-(methylamino)phenol sulphate and 8-hydroxy-1,3,6-trisulfonic trisodium salt acid were prepared and investigated by the magnetic resonance method in the 4–300 K range. Both composites displayed broad and very intense ferromagnetic resonance (FMR) lines originating from γ-Fe2O3 agglomerated nanoparticles. The FMR spectrum was fitted satisfactorily at each temperature by two Landau-Lifshitz functions reflecting the existence of magnetic anisotropy in the investigated system. The temperature dependence of the obtained FMR parameters (resonance field, linewidth, integrated intensity) was studied and the results were interpreted in terms of magnetic interactions between free radicals and nanoparticle agglomerates. A comparison with previously studied similar systems containing maghemite nanoparticles was made and conclusions about the role of free radicals were drawn.

Magnetic resonance study of γ-Fe2O3 nanoparticles dressed in oxygen based free radicals

Solid State Section, Department of Physics, University of Athens, Panepistimiopolis, 15 784, Zografos, Athens, Greece

Institute of Physics, West Pomeranian University of Technology, Al. Piastow 48, 70-311, Szczecin, Poland

Institute of Materials Science, National Centre for Scientific Research “Demokritos“, 153 10 Aghia Paraskevi, Attikis, Athens, Greece

Materials Science-Poland

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Two composites consisting of γ-Fe2O3 (maghemite) nanoparticles covered by two different oxygen-based free radicals derived from a 4-(methylamino)phenol...

Magnetic resonance study of γ-Fe2O3 nanoparticles dressed in oxygen based free radicals

Published Online: Dec 15, 2013

Page range: 587 - 594

DOI: https://doi.org/10.2478/s13536-013-0143-3

Keywords
magnetic nanoparticles, maghemite nanoparticles, magnetic resonance

© 2013 Wroclaw University of Technology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Magnetic resonance study of γ-Fe2O3 nanoparticles dressed in oxygen based free radicals

Published Online: Dec 15, 2013

Page range: 587 - 594

DOI: https://doi.org/10.2478/s13536-013-0143-3

Keywordsmagnetic nanoparticles, maghemite nanoparticles, magnetic resonance

© 2013 Wroclaw University of Technology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
magnetic nanoparticles, maghemite nanoparticles, magnetic resonance