Ionic conduction in zirconia films of nanometer thickness

Polycrystalline 8 mol% Y2O3-stabilized ZrO2 films with thicknesses of 12 and 25 nm were deposited on (100) MgO substrates, their nanostructures were investigated by means of transmission electron microscopy (TEM), high-resolution TEM and atomic force microscopy, and the electrical properties of the nanostructured films were characterized in dry and humid O-2. Compared with microcrystalline bulk ceramics, the ionic conductivity of the nanostructured films is lower by about a factor of 4, which is mainly due to the lower bulk conductivity and the low grain-boundary conductivity. There is not remarkable proton conduction in the nanostructured films when annealed in water vapor, and the influence of the ZrO2/MgO interface on its ionic conduction is negligible. (c) 2005 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.