Zirconia EB-PVD Electrolyte Films: Structure, Mechanical Properties and Conductivity

Structure, elastic modulus and conductivity of EB-PVD 10Sc1CeSZ films deposited on NiO-8YSZ anodes were studied. The films have laminar-columnar structure nucleating as bundles of columns of nano-sized diameter. Two types of lamella could be distinguished with a thickness range of 0.5 - 5.0 mu m and 0.1 - 0.2 mu m, respectively. This structural anisotropy is associated with the distribution of chemical elements across the as-deposited film (Zr, Sc, Ce) and diffusion from the anode (Ni, Y), which most likely is a consequence of instabilities of the deposition process and the condensation mechanism. The elastic modulus of the film is also anisotropic; showing values of 120 GPa at the surface and 105 GPa in the cross-section. Annealing in air increases the elastic modulus up to 140 GPa. The area near the interface with the anode has a higher modulus than that near the surface, which might be associated with the solidification process of the film. The conductivity of the EB-PVD film is half an order of magnitude higher than for a film deposited by screen printing one.