Preparation and characterization of La0.9Sr0.1Ga0.8Mg0.2O3-delta thin film on the porous cathode for SOFC

A dense and crack-free La0.9Sr0.1Ga0.8Mg0.2O3-delta thin film has been prepared by RF magnetron sputtering. The XRD, FESEM, XPS and four-probe technique are employed to characterize the La0.9Sr0.1Ga0.8Mg0.2O3-delta film. Results show that after annealing at 1000 degrees C, the La0.9Sr0.1Ga0.8Mg0.2O3-delta film presents a polycrystalline perovskite structure with grain size of 100-300 nm. XPS data show that both La and Ga are in their +3 state. Sr element has two chemical states which are related to Sr2- in the perovskite lattice and SrO1-delta suboxide. The O 1s spectrum also shows two chemical states which can be assigned to molecularly adsorbed O-2 species and O2- in the lattice. The electrical conductivity reaches to 0.093 S cm(-1) at 800 degrees C. The microstructure and conductivity analysis indicates that the La0.9Sr0.1Ga0.8Mg0.2O3-delta thin film prepared by RF magnetron sputtering is suitable for intermediate temperature Solid oxide fuel cell. (C) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.