Abstract: In this study, initially maghemite (γ- Fe2O3) nanoparticles were synthesized by using of the chemical coprecipitation technique and then the deposited samples were annealed on white glass substrate with thickness (1.2mm) at the temperatures of 400, 450, 500, 550 and 600 °C by spray pyrolysis technique. Their optical properties were investigated by Ultraviolet-visible (UV-vis) spectrometer and structural properties of samples were characterized by infrared (IR) spectrum and X-ray diffraction (XRD). Surfaces morphology and elemental analysis of samples were investigated by scanning electron microscopy (SEM) and Energy dispersive X-ray analysis (EDS) techniques. The results obtained from this study show that by increasing the annealing temperature of the nanoparticles, the particle sizes have grown. This is due to decreases in optical band gap in annealed samples of maghemite nanoparticles. Percent of wavelengths absorbance in the ultraviolet region has been decreased and has been shifted toward visible. Moreover, crystalline structures of materials have been more regulated and deformed from hunk shape to spherical shape.
