SnO_2.Nb_2O_5 films for ethanol sensor, obtained by deposition of alcoholic suspensions

摘要

Films of (1-x)SnO_2. xNb_2O_5 were prepared by the deposition of alcoholic suspensions, using Spin Coating Techniques. The powders used in the preparation of the suspensions were obtained by the polymeric precursor method. Results of X-ray Diffraction (XRD) indicate that the material has a single SnO_2 phase. Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) showed quite homogeneous and porous films, without cracks and with large surface area. The electrical characterization of the samples indicates good sensitivity to ethanol at 200degC, response times in the order to 100 s and resistance in the order of 20 kΩ, at room temperature.