Investigating the Effect of Cobalt Ions on the Optical and Structural Properties of Zinc Ferrite Synthesized by the Sol-Gel Technique

Zinc ferrite with composition (Zn1-xCoxFe2O4) (x = 0, 0.3, 0.4, 0.5, and 0.6) has been prepared using the sol-gel technique. The samples prepared were characterized using X-ray diffractometry (XRD) and transmission electron microscopy (TEM) techniques. The nanocrystallites have been found to have a size range of 63.023–99.036 nm. The optical properties for all samples' absorbance and energy band gap (Eg) were measured by the design of Tauc’s diagram. The indirect and (direct) optical band gaps of the synthesized (Zn1-xCoxFe2O4) ferrite increased from 2.65 eV to 3.40 eV and 4.07 eV to 4.60 eV with increasing the doping percentage of Co as x = 0–0.6. The increase in energy gaps (Eg) value with Co ions doping is possible because of sub-bandgap energy level formation.