Oxygen-vacancy concentration in A2MgMoO6−δ double-perovskite oxides

Accurate oxygen-content analysis by means of a coulometric redox titration method specially devised for the purpose shows that as-synthesized (in 5% H2/Ar) samples of the recently reported novel solid oxide fuel cells anode material Sr2MgMoO6−δ contain oxygen vacancies with a concentration of δ≈0.05. Oxygen contents and the resultant Mo-valence values are also analyzed for various A2MgMoO6−δ samples in order to reveal both the isovalent and aliovalent A-site cation substitution effects.