Gadolinia-doped ceria-based films (GDC) were deposited on quartz substrates by spray pyrolysis. The films were deposited with Gd concentration of 0, 10, 20 and 30 at.%. The influence of doping concentration (Gd) and water/alcohol ratio, used as solvent in precursory solution, on structural, morphological, compositional and electrical properties of the GDC films was investigated. The analyses by X-ray diffraction showed polycrystalline films with a cubical structure of the fluorite type and preferential orientation (200). It was observed that the film growth is strongly dependent on the water/alcohol ratio used in the preparation of the precursory solution, could result in the growth of films with columnar structure. The results obtained by AFM and SEM indicated that the films are dense and free from cracks. Annealing of the films modified their level of crystallinity and crystallite size significantly. Analyses by X-ray fluorescence showed that the stoichiometry used in the precursory solution was kept in the films. Measurement of the variation of the electrical conductivity as a function of temperature showed that the doped films with 20 at. % presented higher electrical conductivity than the intrinsic films.
Solid Oxide Fuel Cells; spray pyrolysis; ceria; GDC; films
