Conductivity study of porous yttria-doped zirconia and strontia-doped lanthanum manganite bilayer film by glancing angle deposition

Porous bilayer films of yttria-doped zirconia and strontia-doped lanthanum manganite are deposited by using electron beam evaporation. For practical use in solid oxide fuel cells, fully-stabilized zirconia is a candidate for the solid electrolyte due to its high oxygen diffusion rate. Longer triple phase boundary, which consists of catalyst, reacting gas and solid electrolyte in the cathode, is helpful for the exchange of oxygen gas and ions. By glancing angle deposition, higher density of triple phase boundary is achieved in the form of catalyst and electrolyte bilayer structure. This kind of triple phase boundary can be estimated from SEM images and it is rather easier than from conventional composite cathode which can only be analyzed with assistance of mathematic simulation. The resistance of this bilayer at 600 °C is ten times lower than porous catalyst single layer.