Iron-zinc oxide films prepared by ultrasonic spray pyrolisis

Starting from an aqueous nitrate solution, iron-zinc oxide films were prepared by the ultrasonic spray pyrolisis method. Films with different contents of zinc (2, 3, 30 and 50 at. %) were prepared by adding the appropriate zinc acetate amount to the solution. Sample deposited at several temperatures (50, 150, 250, 350 and 450 °C) were studied by means of optical (UV-vis and mid-infrared ranges) and XRD measurements. Several phases, FeO, α-Fe₂O₃ and ZnFe₂O₄, depending on the deposition temperature and Zn concentration, were observed. The Zn content in the film controlled the microstructure. A very rough surface morphology was found from AFM observations (RMS roughness ≫ 560 nm), making the films potentially useful for gas sensor applications.