Correlation of synthesis parameters to the structural and magnetic properties of spinel cobalt ferrites (CoFe2O4) - an experimental and statistical study

Several studies have shown the exceptional responses of spinel cobalt ferrites as advanced ceramics. Nevertheless, there is still a gap in the literature regarding the effect of synthesis parameters on the properties of the spinel products. This work aims to correlate temperature and annealing time with the structural, optical, and magnetic properties of CoFe2O4. Precursors were prepared by sol-gel and thermally treated at 550, 650, and 750 degrees C for 2, 4, and 6 h. The microstructure was characterized by XRD, BET, SEM, and Raman spectroscopy. Treatment longer than 6 h at temperatures higher than 650 degrees C produced less inverted nanoparticles with larger crystallites. Although the initial annealing conditions did not influence the ferrites bandgap, VSM results showed an opposite response. The maximum in coercivity (1654.25 Oe) was obtained in the sample annealed in the shortest time (2 h) and at the lowest temperature (550 degrees C). Statistical analyses prove that despite not affecting the results in the same manner, both initial conditions affected the CoFe2O4 properties. Our results open up the possibility of improving the CoFe2O4 manufacturing process for commercial exploration.