The oxygen-exchange behavior was studied in half-doped manganese and cobalt perovskite oxides. It was found that the O diffusivity in Gd0.5Ba0.5MnO3–δ could be enhanced by orders of magnitude by inducing crystallographic ordering among lanthanide and alkali-earth ions in the A-site sub-lattice. Transformation of a simple cubic perovskite, with randomly occupied A sites, into a layered crystal GdBaMn2O5+x (or isostructural GdBaCo2O5+x for cobalt oxide) with alternating lanthanide and alkali-earth planes reduces the O bonding strength and provides disorder-free channels for ion motion, pointing to an efficient way to design new ionic conductors.

Achieving Fast Oxygen Diffusion in Perovskites by Cation Ordering. A.A.Taskin, A.N.Lavrov, Y.Ando: Applied Physics Letters, 2005, 86[9], 091910 (3pp)