Magnetic properties and self‐heat behaviors of core@shell structured MnFe₂O₄@Fe₃O₄ magnetic nanoparticles

Abstract

In this work, a facile solvothermal synthesis of MnFe2O4 nanoparticles is followed by an easy and reproducible process to envelop the synthesized MnFe2O4 nanoparticles with iron oxide nanoparticles using ethanol and ethylene glycol as solvents. All prepared MnFe2O4 nanoparticles show a homogenous distribution of spherical particles with an average particle size between 12 and 16 nm. The encapsulation process of MnFe2O4 nanoparticles does not affect their homogenous distribution with a very thin layer of Fe3O4 on the shell structure. The magnetic properties showed a superparamagnetic character with enhanced magnetic properties of MnFe2O4@Fe3O4 compared to pure MnFe2O4, which has been verified by magnetization and electron spin resonance. The heating efficiency of the prepared samples was evaluated in terms of the specific loss power using the calorimetric method. The synthesized MnFe2O4 nanoparticles show a significantly high value of about 72 W/g, which got doubled in the core@shell structure and reached 140 W/g at 189 kHz and 10kA/m of the magnetic field.