Atomic force microscopy study of TiO2 sol–gel films thermally treated under NH3 atmosphere

Abstract Multilayered TiO 2 films were obtained by sol–gel and dipping deposition on quartz substrate followed by thermal treatment under NH 3 atmosphere. In an attempt to understand the close relationship between microstructural characteristics and the synthesis parameters, a systematic research of the structure and the morphology of NH 3 modified TiO 2 sol–gel films by XRD and Atomic Force Microscopy is reported. The surface morphology has been evaluated in terms of grains size, fractal dimension and surface roughness. For each surface, it was found a self-similar behavior (with mean fractal dimension in the range of 2.67–3.00) related to an optimum morphology favorable to maintain a nano-size distribution of the grains. The root mean square (RMS) roughness of the samples was found to be in the range of 0.72–6.02 nm.