The implementation of sustainable energy technologies, including solid oxide fuel cells (SOFC's) and solid-state batteries, is reliant of the discovery of materials that exhibit improved levels of oxygen conductivity at low to moderate temperatures. However, progress is currently being hindered by a lack in understanding of the core factors which govern ionic conductivity in transition metal oxides. In the hopes of elucidating the role and impact of transition metal interactions on these properties, we are investigating oxygen intercalation/de-intercalation reactions in materials based on the perovskite structure. These topotactic reactions allow us to study how the systematic modulation of the anionic sublattice, and the accompanying changes in the type and strength of the metal-metal interactions relate to changes in oxygen conductivity properties. Specifically, we will highlight our research with the double perovskite Sr2FeMoO6 (SFMO),a material already the subject of intense research due to its potential application in spintronic devices. We have used advanced scattering techniques, both neutron and X-ray, to study the effects of these topotactic reactions on the structure, both magnetic and atomic, of this material. Furthermore, by focusing on double perovskites, we are gaining insight into the effects of not only the anionic sublattice, but also of transition metal ordering and substitution on oxygen conductivity properties. The differing ionic radii, redox potentials, and oxidation states of the two transition metals modulate the electronic surface around each metal site and therefore affect the outcome of the oxygen intercalation/de-intercalation reactions.

Modulating oxygen activity through topotactic treatments in double perovskite-based materials

248th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.