Composite Ce0.8Gd0.2O2-δ (solid electrolyte) and La0.7Sr0.3MnO3-δ (electronic conductor) ceramics were tested. It was found that O permeation through composite ceramics which contained similar percentages of both phases was limited by bulk ionic transport. Unlike electronic transport, O ion transport in the composites depended strongly upon processing conditions and decreased with interdiffusion of the components. Ions of O were blocked by low ionic conductivity layers which were formed by the diffusion of cations of La0.7Sr0.3MnO3-δ to the contacts between Ce0.8Gd0.2O2-δ grains. Testing of composite membranes at high O pressures (1 to 50atm) showed that the composite ceramics were stable under these conditions, and exhibited Wagner-type permeation fluxes.

Oxygen Permeability and Faradaic Efficiency of Ce0.8Gd0.2O2-La0.7Sr0.3MnO3 Composites. V.V.Kharton, A.V.Kovalevsky, A.P.Viskup, F.M.Figueiredo, A.A.Yaremchenko, E.N.Naumovich, F.M.B.Marques: Journal of the European Ceramics Society, 2001, 21[10-11], 1763-7