Oxygen permeation through thin zirconia/yttria membranes prepared by EVD

Ultra-thin dense zirconia/yttria membrane composites were fabricated by EVD technique on porous α-alumina substrates. The deposited membranes consisted primarily of cubic/tetragonal phases as determined by XRD. The EVD film growth rate estimated by SEM photographs was 3-4 μm/h. Oxygen permeation data of thin dense zirconia/yttria membranes with different thickness (2-15 μm) were measured at 900°C and 1000°C. From the oxygen permeation data, the surface reaction and bulk diffusion rate parameters, α and β, were calculated. At 900°C, α = 3.0 × 10^-8 mol/cm² · s · atm^1/2 and β = 3.0 × 10^-8 mol/cm · s · atm^1/4 with activation energy 53 KJ/mol and 72 KJ/mol for α and β, respectively. Presence of steam in the high oxygen partial pressure side promoted electrochemical surface reaction.