Impact of Rare Earth Gd3+ Ions on Structural and Magnetic Properties of Ni0.5Zn0.5Fe2−x Gd x O4 Spinel Ferrite: Useful for Advanced Spintronic Technologies

In this article, we have synthesized the Gd3+-doped Ni0.5Zn0.5Fe2−x Gd x O4 (x = 0.05, 0.07, 1.0) ferrite samples using solid-state reaction route. The effects of Gd3+ doping on structural, vibrational, electrical and magnetic properties were studied. Structural and vibrational properties were characterized by x-ray diffraction (XRD), Raman, and FTIR spectroscopy. XRD data indicate that the Ni0.5Zn0.5Fe2−x Gd x O4 ceramics crystallize in single-phase spinel cubic (Fd3m space group) structure. Infrared spectra show two strong absorption bands in the frequency range of 400–600 cm−1 which were, respectively, attributed to tetrahedral and octahedral sites of the spinel ferrite. All the prepared samples show the typical dielectric dispersion having Maxwell–Wagner-type interfacial polarization. Decrease in dielectric constant and loss tangent has been observed with frequency and doping concentration. M − H plots reveal that all the samples exhibit ferrimagnetic nature at room temperature. A significant increase in the saturation magnetization has been observed upon the substitution of Gd3+ ions. All the as-prepared samples are isotropic and soft magnetic materials. These ferrite compounds are advantageous in advanced high-density data storage and high-frequency devices applications.