RUS  ENG
Full version
JOURNALS // Fizika Tverdogo Tela // Archive

Fizika Tverdogo Tela, 2018 Volume 60, Issue 2, Pages 375–382 (Mi ftt9315)

This article is cited in 15 papers

Low dimensional systems

Mössbauer studies of core-shell FeO/Fe$_{3}$O$_{4}$ nanoparticles

A. S. Kamzina, A. A. Valiullinb, H. Khurshidc, Z. Nematic, H. Srikanthc, M. H. Phanc

a Ioffe Institute, St. Petersburg
b Kazan (Volga Region) Federal University
c University of South Florida, Department of Physics

Abstract: FeO/Fe$_{3}$O$_{4}$ nanoparticles were synthesized by thermal decomposition. Electron microscopy revealed that these nanoparticles were of the core-shell type and had a spherical shape with an average size of $\sim$20 nm. It was found that the obtained FeO/Fe$_{3}$O$_{4}$ nanoparticles had exchange coupling. The effect of anisotropy on the efficiency of heating (hyperthermic effect) of FeO/Fe$_{3}$O$_{4}$ nanoparticles by an external alternating magnetic field was examined. The specific absorption rate (SAR) of the studied nanoparticles was 135 W/g in the experiment with an external alternating magnetic field with a strength of 600 Oe and a frequency of 310 kHz. These data led to an important insight: the saturation magnetization is not the only factor governing the SAR, and the efficiency of heating of magnetic FeO/Fe$_{3}$O$_{4}$ nanoparticles may be increased by enhancing the effective anisotropy. Mössbauer spectroscopy of the phase composition of the synthesized nanoparticles clearly revealed the simultaneous presence of three phases: magnetite FeO/Fe$_{3}$O$_{4}$, maghemite $\gamma$-Fe$_{2}$O$_{3}$, and wustite FeO.

Received: 26.06.2017

DOI: 10.21883/FTT.2018.02.45396.210


 English version:
Physics of the Solid State, 2018, 60:2, 382–389

Bibliographic databases:


© Steklov Math. Inst. of RAS, 2024