A series of optimised materials in the family with parent compound La2Mo2O9 were studied by using the isotope exchange depth profile technique and secondary ion mass spectrometric analysis. The data collected indicated that the oxide ion diffusion coefficients in both the parent compound and optimised materials were significantly higher than those reported for any of the fluorite structured electrolyte materials, with a peak value for the La1.7Gd0.3Mo2O9 composition of 1.41 x 10-6cm2/s at 800C. Furthermore, it was found that the substitution of isotopic O into the ceramic was limited in dry atmospheres but significantly enhanced in a H218O/16O atmosphere, in common with recent reports on the diffusion/exchange behaviour of the BIMEVOX class of oxide ion conductors.

Oxide Ion Diffusion in Optimised LAMOX Materials. S.Georges, S.J.Skinner, P.Lacorre, M.C.Steil: Dalton Transactions, 2004, 19, 3101-5