Enhanced electrical and magnetic properties of Gd-doped Ni-Zn ferrites for energy storage applications

Gadolinium (Gd³⁺)-substituted Ni₀.₈Zn₀.₂Gd_xFe_2-xO₄ spinel ferrites (x = 0.00, 0.05, 0.10, 0.15, 0.20) were synthesized using the citrate-gel auto-combustion technique. X-ray diffraction confirmed the formation of a cubic spinel structure, with an increase in average crystallite size upon Gd³⁺ substitution, while the lattice parameter showed a decreasing trend. Field emission scanning electron microscopy revealed agglomerated particles with homogeneous dispersion, and a reduction in grain size due to doping. Energy dispersive X-ray spectroscopy confirmed the presence of the expected elements. Fourier-transform infrared spectroscopy identified tetrahedral and octahedral vibrational bonds (ν₁ and ν₂), from which the force constants (K_T and K_O) were determined. Electrical measurements, including dielectric constant, dielectric loss, and AC conductivity, were conducted at room temperature, showing a decreasing trend with increasing Gd³⁺ content. Magnetic characterization indicated a reduction in saturation magnetization and an increase in coercivity. The incorporation of Gd³⁺ into Ni-Zn ferrites notably influenced both the electrical and magnetic properties of the synthesized materials. Which are suitable for communication and energy storage systems.