Enhanced structural, magnetic, and dielectric properties in Cr3+-substituted Mg0.5R0.5Fe1.5Cr0.5O4 (R = Cu, Zn) ferrites

This study examines the structural, microstructural, magnetic, and dielectric properties of Cr3+-substituted ferrites, specifically Mg0.5Cu0.5Fe1.5Cr0.5O4 and Mg0.5Zn0.5Fe1.5Cr0.5O4, synthesized using the solid-state reaction method. Structural and phase purity assessments were conducted via x-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy, and Vibrating Sample Magnetometry. XRD patterns confirmed the formation of a single-phase cubic spinel structure in both ferrites, with derived lattice parameters (8.402 and 8.497 Å) and crystallite sizes (44.70 and 30.05 nm) supporting consistent structural integrity. SEM analysis in association with ImageJ software showed grain sizes between 732 and 324 nm, while FTIR spectra revealed characteristic tetrahedral and octahedral vibration bands. Notably, the saturation magnetization increased significantly with Cu2+ concentration, from 38.67 to 60.45 emu/g, indicating an enhancement in magnetic properties. The dielectric behavior, analyzed over a 100–105 Hz range, exhibited Maxwell–Wagner interfacial polarization and electron hopping effects between Fe2+ and Fe3+ ions, contributing to typical dispersion patterns. This improvement in magnetic and dielectric properties, particularly in the Cu-doped samples, underscores the effectiveness of Cr3+ substitution in tuning material characteristics. The findings suggest that these modified ferrites hold promise for high-frequency electronic applications, such as inductors, transformers, and electromagnetic interference shielding materials, where both magnetic stability and efficient dielectric performance are critical. This research contributes valuable insights into the development of advanced ferrites for multifunctional electronic devices.