Sr2MgMoO6-δ: Structure, Phase Stability, and Cation Site Order Control of Reduction

This is the authors' abstract. We don't add key points for this paper.

The potential solid oxide fuel cell anode material Sr 2 MgMoO 6 adopts a √2 × √2 × 2 I1̄ superstructure of the simple perovskite cell, derived from an a 0 a 0 c - tilt system via distortion of the Mg- and Mo-centered octahedra. Reduction of Sr 2 MgMoO 6 appears to be correlated with antisite disorder at either point or extended antiphase defects. The degree of reduction is small at temperatures below 900 °C. Upon further reduction above 900 °C, Sr 2 MgMoO 6 begins to decompose into a reduced material modeled as an n = 2 Ruddlesden−Popper phase with a significantly higher Mo:Mg ratio, MgO, and Mo. Diffraction data are consistent with the reduced material being significantly intergrown with the perovskite matrix.