Nickel ferrite nanomaterials: Synthesis, characterization and properties

In the present study, AB₂O₄ type nickel ferrite (NiF e₂O₄) nanoparticles (NPs) were prepared by a coprecipitation method. The crystal structure, phase purity, morphology, optical and kinetic properties of the NiFe₂O NPs were investigated by X-ray diffraction (XRD), Rietveld refinement, scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) and UV-Visible spectroscopy. The XRD diffraction pattern revealed the degree of crystallinity and confirming the cubic spinel system with the space group of Fd. 3m:2, a typical crystal structure of nickel ferrite spinel. The SEM studies exhibited that the synthesized NiFe₂O NPs had an average particle size of ∼55 nm. Two stage decomposition pattern was observed for both as-synthesized and calcined NiFe₂O NPs. The TGA was further used to analyze the Coats-Redfern and Friedman methods in order to estimate the decomposition activation energy (Eα) which revealed that it obeyed the F1 solid-state nucleation-growth mechanism. Finally, a schematic mechanism for preparation of the AB₂O₄ type nickel ferrite NPs was proposed.