Structural, optical and magnetic properties of CoFe2O4 nanoparticle synthesized by ultrasonication-assisted sol–gel technique.

In this paper, we have synthesized CoFe2O4 nanoparticles by ultrasonication-assisted sol–gel technique at a lower temperature (600 °C), mainly to comprehend the impact of cation redistribution at tetrahedral and octahedral sites on structural, optical, and magnetic properties. The analysis of the synthesized compounds by Rietveld's refined X-ray diffraction pattern reveals that the synthesized compound crystallizes in a cubic structure with Fd-3m space group. The obtained crystallite size is found to be 12.37 nm estimated from Hall–Williamson plot. The FE-SEM results depicted the formation of particle in spherical shape and flake-like grain structure. Moreover, the ultra-violet–visible (UV–Vis) spectroscopic study revealed the semiconductor nature of synthesized CoFe2O4 compound with direct bandgaps of around 1.76 eV. In the magnetization study, the saturation magnetization and remanence field are shown in decreasing nature whereas the coercivity value increases from room temperature to 5 K. The acquired variation between 5 and 300 K is because of the interaction between the distribution of cations at different tetrahedral and octahedral sites. The cationic redistribution and calcination temperature is responsible forthe significant change in optical energy bandgap and magnetic properties of CoFe2O4 nanoparticles. The improved magnetic properties and significant change in optical energy bandgap due to cationic redistribution and calcination temperature are advancements for the scientific community. [ABSTRACT FROM AUTHOR]