Effect of gadolinium on magnetic circular dichroism and electron magnetic resonance of ε-Fe2O3 nanoparticles formed in borate glasses

Irina Edelman (1) , Janis Kliava (2) , Oxana Ivanova (1) , Ruslan Ivantsov (1) , D. Velikanov (1, 3) , Vladimir I. Zaikovskii (4) , Eleonora Petrakovskaja (1) , Y. Zubavichus (5) , Stepanov S. (6)

1 Kirensky Institute of Physics
2 LOMA - Laboratoire Ondes et Matière d'Aquitaine
3 SibFU - Siberian Federal University
4 Boreskov Institute of Catalysis
5 NRC KI - National Research Centre "Kurchakov Institute"
6 S.I. Vavilov State Optical Institute

A remarkable characteristic of borate glasses is the ability of forming magnetic nanoparticles at low doping with transition element oxides. We have studied structure and magnetic properties of iron oxide nanoparticles formed in borate glasses, in particular, concentration and temperature dependences of magnetic circular dichroism (MCD) and electron magnetic resonance (EMR) spectra. A series of glasses of molar composition 22.5K 2 O-22.5Al 2 O 3-55B 2 O 3 doped with 1.5 mass % of Fe 2 O 3 and different contents of Gd 2 O 3 from 0.1 to 1.0 mass % was prepared using a conventional melt quenching technique and subjected to an additional thermal treatment. The whole set of results allows to identify the predominant magnetic phase in these glasses as ε-Fe 2 O 3 nanoparticles, with a considerable part of iron ions substituted by gadolinium. Analysis and computer simulations of the EMR spectra allow separating the contribution of electron paramagnetic resonance of diluted iron ions and together with the temperature dependences of magnetization demonstrate a superparamagnetic character of the nano-particle magnetism.

Mots clés: Iron oxides; Borate glasses; Nanoparticles; Magnetic circular dichroism; Electron magnetic resonance

Domaines: Electromagnétisme

Irina Edelman, Janis Kliava, Oxana Ivanova, Ruslan Ivantsov, D. Velikanov, et al.. Effect of gadolinium on magnetic circular dichroism and electron magnetic resonance of ε-Fe2O3 nanoparticles formed in borate glasses. Journal of Non-Crystalline Solids, 2019, 506, pp.68-79. ⟨10.1016/j.jnoncrysol.2018.12.006⟩. ⟨hal-02018140⟩