Effect of cerium ion doping: Alteration in structural, dielectric and magnetic properties of manganese ferrite nanoparticles

Abstract

The present study reports the effect of Ce-substitution on the structural, chemical, magnetic and dielectric properties of manganese ferrite (MnCe_xFe_2-xO₄; x = 0.00–0.15, 0.025) NPs. Ferrite NPs were synthesized via citrate-assisted sol-gel auto-combustion method and annealed at 400^oC. Rietveld refinement XRD patterns validated the cubic spinel phase Ce-doped MnFe₂O₄ NPs with fd $\bar{3}$ m space group. The crystallite size was found in the range of 10.01 ± 0.01 to 19.4 ± 0.3 nm. The FTIR spectrum of Ce-doped MnFe₂O₄ NPs revealed the formation of pure spinel phase. FESEM images of cerium-doped manganese ferrite NPs reveal agglomerated spherical particles with porous surfaces. The homogeneous substitution and elemental composition were confirmed through EDX spectra and elemental mapping. The saturation magnetization of MnFe₂O₄ decreased with Ce substitution (51.7–13.3 emu/g). For x = 0.15, MnCe_xFe_2-xO₄ NPs exhibited minimum dielectric loss, maximum dielectric constant, and moderate AC conductivity. Relaxation time and spreading factor were also calculated by using a modified Debye's model. MnCe_xFe_2-xO₄ NPs (x = 0.15) showed optimum magnetic and dielectric behaviour making it a potential candidate for electromagnetic shielding application and high-frequency applications.