Influence of Ta2O5 additive on the structural, optical and magnetic properties of Ni-Cu-Zn nanocrystalline spinel ferrites

In present work, nanocrystalline Ni0.4Cu0.3Zn0.3Fe2O4 (NiCuZn) ferrites with varying weight percent of Ta2O5 were prepared by sol gel method. X-ray Diffraction, field emission scanning electron microscopy, Fourier transform infrared spectroscopy, Energy disperse x-ray spectroscopy, UV-visible diffusion reflectance spectroscopy and vibrating sample magnetometer are used to characterize the prepared samples. The Rietveld refinement of XRD pattern shows the formation of single-phase cubic spinel structure. The secondary phase is observed in NiCuZn with the increasing Ta2O5 additive. Secondary phase is marked as Pb4(2)/mnm space group. The lattice parameter of NiCuZn ferrite has decreased with the increasing Ta2O5 additive. An FTIR spectrum shows two prominent peaks. FESEM observations indicate the agglomeration among the prepared ferrite. The elemental composition obtained by EDX validates the presence of Ni, Cu, Zn, Ta, and Oxygen in the prepared samples. The band gap energies obtained from UV-Visible spectra's are estimated in the range of 2.55 eV to 2.90 eV. Magnetic hysteresis loops of NiCuZn ferrites for the 2 wt% and 3 wt% samples show the normal ferrimagnetic behavior with a small coercivity, indicating the soft magnetic nature of the prepared samples.