Structural, optical and magnetic properties of Ce3+- substituted MgCexFe2-xO4 (0.00, 0.05, 0.10) nanoferrites

Abstract

Ce3+ - doped MgFe2O4 nano-ferrites were synthesized through the citrate gel auto-combustion method to examine how rare-earth incorporation affects its structural, optical, and magnetic properties. Although Ce-substituted ferrites have been reported previously, comprehensive investigations on low-level Ce3+ substitution (x = 0.00, 0.05, and 0.10) in MgFe₂O₄ nanoferrites synthesized by the citrate gel auto-combustion method are limited. The present study systematically correlates structural, thermal, optical, and magnetic properties using complementary characterization techniques (XRD, SEM/EDX, FTIR, UV–Visible spectroscopy, TG-DTA, and VSM). The work demonstrates how Ce3+ incorporation modifies lattice parameters, crystallite size, metal–oxygen bonding, optical band gap, and magnetic parameters (Ms, Mr, and Hc), thereby providing a comprehensive understanding of the structure–property relationship in Ce-substituted magnesium ferrites. This integrated investigation distinguishes the present work from previous reports that mainly focus on individual properties. As Ce3+ doping concentrations increased, it was observed that the crystallite size decreased and the lattice constant increased. This type of behavior is explained by the higher ionic radii of Ce3+ ions than Fe ions. A shift in the metal-oxygen (M-O) stretching vibrations was also noted, leading to the lattice expansion. FTIR spectra investigation revealed the significant peaks related to ferrite phases. The homogeneous particle size distribution was revealed by scanning electron microscopy (SEM), with a minor reduction in crystallite size at higher Ce concentrations. The optical band gap (Eg) was observed to depend on the Ce doping concentration. The TG-DTA analysis confirmed the crystallization temperature of the synthesized ferrite. The M–H hysteresis loops confirm that all MgCexFe2-xO4 samples exhibit soft ferrimagnetic behavior, characterized by low coercivity and narrow hysteresis loops. The initial decrease in saturation magnetization (Ms) with Ce3+ substitution is attributed to magnetic dilution caused by the replacement of Fe3+ ions at octahedral (B) sites and the consequent weakening of Fe3+ –O2 − –Fe3+ super-exchange interactions. The slight recovery in Ms at ×=0.10 may result from partial cation redistribution and reduced surface spin disorder. The continuous decrease in coercivity (Hc) indicates reduced magnetocrystalline anisotropy and enhanced domain-wall mobility due to lattice distortion induced by Ce3+ incorporation. These results demonstrate that controlled Ce3+ substitution effectively tailors the magnetic properties of MgFe₂O₄ nanoferrites, making them promising candidates for soft magnetic devices, high-frequency components, and electromagnetic interference (EMI) shielding applications. Rare-earth substitution was found to be one method of enhancing the structural, optical, and magnetic characteristics of MgCe ferrite so that they may be tailored for sophisticated and practical scientific uses.