A comparative study of the magnetic induction heating properties of rare earth (RE = Y, La, Ce, Pr, Nd, Gd and Yb)-substituted magnesium–zinc ferrites

Abstract

Rare earth (RE)-substituted magnesium–zinc ferrite (Mg0.5Zn0.5RExFe2–xO4) nanoparticles with different RE elements (Y, La, Ce, Pr, Nd, Gd and Yb) and different RE contents (x = 0–0.1) were synthesized via coprecipitation of metal hydroxides as the precursor, followed by calcination. Their crystal structures were characterized by X-ray diffraction (XRD) analysis, confirming that the RE-substituted Mg–Zn ferrites had a single-phase spinel structure at low x values. However, the Ce-substituted ferrites contained CeO2 as a byproduct. Scanning electron microscopy (SEM) showed that the particle diameters of the samples decreased from approximately 100 to 20 nm as x was increased regardless of the RE elements. The magnetic induction heating properties were evaluated using the intrinsic loss power (ILP) determined from the temperature rise profiles in an alternating magnetic field and the amplitude and frequency of the magnetic field. By using various RE elements, it was found that the increase in the magnetic moment of RE ions can increase the magnetization of ferrites, resulting in improvements in the ILP at low RE contents, except for Gd substitutions. The increase in RE content decreased the ILP due to reductions in crystallinity. The results suggest that the RE elements and contents can precisely control the magnetic induction heating properties, and RE-substituted Mg–Zn ferrite nanoparticles are promising candidates for magnetic hyperthermia applications.