Yttria-stabilized Bi2O3(YSB) thin films have been deposited using reactive direct current (d.c.) magnetron cosputtering from Y and Bi targets. The films were deposited in argon/oxygen sputtering gas mixtures onto silica glass, NaCl, and MgO substrates. (Y2O3)x(Bi2O3)1-xthin films with × = 0.25-0.5 were obtained under metalhc mode sputtering conditions, but were found to be ≈10% oxygen deficient. Post-deposition annealing in air at T≳ 500°C led to fully stoichiometric films. X-ray diffraction and transmission electron microscope (TEM) studies showed that the structure of the annealed films was cubic with lattice parameters following Vegard's law. The films were dense as judged by scanning electron microscope (SEM) and TEM. Complex impedance spectroscopy measurements were carried out in air on × = 0.25 films with Ag-(La0.7Sr0.3)CoO3cermet electrodes. The temperature dependent ionic conductivity exhibited a knee point at Td≈ 870°K, with activation energies of 1.2 eV below Td and 0.96 eV above Td, in good agreement with values for bulk YSB with the same composition. The interracial resistance of the cermet with 30 volume percent (v/o) Ag on a YSB electrolyte thin film was ≈0.3 Ω cm2at 750°C.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Materials Chemistry