The 18O/16O isotope exchange depth profile technique was applied to BE25 ((Bi2O3)0.75(Er2O3)0.25) and BICAO ((Bi2O3)0.73–(CaO)0.27) dense ceramics to characterize the O transfer in these materials. Pure ceramics, ceramics coated with silver on the surface and 40%Ag cermets were investigated. Slow O surface exchange kinetics were confirmed for the pure ceramics whilst the kinetics were improved when Ag was painted onto the surface. However O permeation fluxes were not improved when a Ag paste was painted onto the membrane surface. Permeation was also limited by electronic conduction which was likely to be more limiting than O exchange at the surface of the ceramics. In contrast, fast kinetics of O surface exchange were revealed for cermets.

Oxygen Permeation in Bismuth-Based Materials - Characterisation of Oxygen Transfer in Bismuth Erbium Oxide and Bismuth Calcium Oxide Ceramic. E.Capoen, G.Nowogrocki, R.J.Chater, S.J.Skinner, J.A.Kilner, M.Malys, J.C.Boivin, G.Mairesse, R.N.Vannier: Solid State Ionics, 2006, 177[5-6], 489-92