In this study, a chemical route was adopted to obtain strontium-doped lanthanum manganite (LaSrMnO3 or LSM) powders in order to prepare LaSrMnO3-4YSZ (4 mol% Y2O3) composite films by the suspension spin coating method onto 4YSZ and 8YSZ/8YSZ-NiO substrates with or without the application of a zirconia interlayer in the film/substrate interface. The multilayers were sintered at 1150 oC for 6 h and the effect of the interlayer on the morphological properties of the films has been investigated by scanning electron microscopy. The results show that in the less roughn substrates the application of the interlayer (~500 nm) not only improved the adhesion in the film/substrate interface, but also avoided new coating failures. All the films were porous, crack-free and with a thickness below 30 μm, desirable features for application as SOFC cathodes.

Keywords: Composite cathodes, interlayer, microstructure, spin coating, SOFC.