Preparation and characterization of Co3O4 films prepared via Pechini method

Co3O4 thin films were prepared via the Pechini method using spin-coating and sintering processes. X-ray diffraction (XRD), atomic force microscopy (AFM), and Raman spectroscopy were employed to characterize the films. The XRD pattern from the prepared films can be indexed based on a spinel structure. Ordered crystalline columns and high quality surfaces are observed via the AFM images. It is found out that the grain size increases with the sintering temperature. Minimum roughness of the film can be obtained at PEG content 60 mg/ml. Raman spectroscopy confirms that the films are crystallized in the spinel structure. A red shift observed in all bands shows that the cohesive energy is lower in the film than in the bulk crystal.