Impact of Nd3+ doping on Mg0.5Zn0.5Fe2O4 nano-ferrite: structural, morphological, electrical resistivity, and magnetic properties

• XRD analysis confirmed a pure cubic spinel structure with no impurity phases. • FESEM analysis showed spherical grains with sizes ranging from 50 to 90 nm. Increasing Nd³⁺ concentration resulted in agglomerated particles, indicating a significant impact of doping on grain morphology. • Magnetic hysteresis studies indicated a transition from hard to soft magnetic behavior with doping. Saturation magnetization decreased (32.19 to 23.71 emu/g), and coercivity also reduced, which is beneficial for magneto-recording applications. • DC resistivity increased significantly with Nd³⁺ doping due to reduced electron hopping between Fe²⁺ and Fe³⁺ ions, demonstrating semiconducting behavior. This higher resistivity is advantageous for reducing eddy current losses. • The FTIR spectra revealed shifts in absorption bands corresponding to tetrahedral and octahedral sites, indicating the successful incorporation of Nd³⁺ ions into the lattice, modifying the material's vibrational characteristics. A homogeneous composite of ferrite oxide samples with the chemical formula Mg 0.5 Zn 0.5 Fe 2-x Nd x O 4 (0 ≤ x ≤ 0.10) was prepared via the sol-gel auto-combustion method, with Nd content varying in steps of 0.02. The Nd³⁺ ion concentration significantly influenced the Mg-Zn ferrites' magnetic properties and DC electrical resistivity. Room temperature X-ray diffraction (XRD) analysis verified a pure cubic structure with an Fd3m space group, showing no traces of impurity phases. The crystallite sizes varied between 35 and 52 nm, while the lattice parameters expanded from 8.392 to 8.418 Å with higher doping levels. Field emission scanning electron microscopy (FESEM) displayed spherical grains with an agglomerated structure, with grain diameters varying from 49 to 103 nm. Fourier-transform infrared (FTIR) spectroscopy showed two metallic bands consistent with cubic spinel ferrites. The magnetic properties, including coercivity (Hc), saturation magnetization (Ms), retentivity (Mr), squareness ratio (SQR), and hysteresis loops at room temperature, were analyzed using a vibrating sample magnetometer (VSM). The saturation magnetization values, which ranged from 32.19 to 23.71 emu/g, and the squareness ratio values, which ranged from 0.43 to 0.35, indicated a change from hard to soft magnets. According to a two-probe approach, the room temperature DC resistivity of the nanopowders was roughly 10 7 Ω•cm.