Tuning the structural, optical and magnetic properties of NiCuZn (Ni0.4Cu0.3Zn0.3Fe2O4) spinel ferrites by Nb2O5 additive

Abstract

Ni0.4Cu0.3Zn0.3Fe2O4 ferrites with various compositions (0–5 wt. %) of Nb2O5 additive were synthesized by the sol-gel method with an aim to investigate their physical properties. The analysis of Rietveld refined X-ray diffractograms confirms formation of ferrites with a single-phase spinel structure having space group Fd3m. The result indicates that there is an enhancement in the lattice parameter values with increasing Nb2O5 content. The nanoparticles in the shapes of spheres and cubes with few agglomerations were evident from field emission scanning electron microscope images of ferrites. The elemental analysis from energy dispersive X-ray spectrum confirms the stoichiometric occurrence of constituent elements within the prepared samples. The Raman spectra confirm the cubic spinel structure of the prepared ferrite samples. The Fourier transform infra-red spectra confirm the superseding of Nb5+ ions in the unit cell of NiCuZn ferrite. Oxidation states of the elements within the ferrite were confirmed by means of X-ray photoelectron spectroscopy. The UV–Visible diffused reflectance spectroscopy results show that the band gap energy values were reduced with the increasing wt.% of Nb2O5 additive in the ferrite. The Nb2O5 additive reduces the saturation magnetization and coercivity of all the ferrite samples. The study reveals that the controlled amount of Nb2O5 additive in NiCuZn ferrite can tune the soft magnetic behavior and optical parameters of the ferrite at room temperature.