Past event

School of Chemistry Colloquium: Professor Abbie McLaughlin (University of Aberdeen) Investigation of Ionic Conductivity and Exotic Electronic Properties in Transition Metal Oxides

Solid-oxide fuel cells (SOFCs) and proton ceramic fuel cells (PCFCs) offer a viable option to produce clean energy from sustainable resources, with low emission of pollutants, fuel flexibility and high energy conversion rates. New materials, which exhibit high ionic conductivity (≥ 10 mS cm-1) at intermediate temperatures (< 600 슰C), are sought for the next generation of ceramic fuel cells. Such fuel cells will be more cost-effective and have greater longevity. We have recently discovered high oxide ion and proton conductivity at 500 슰C in the hexagonal perovskite derivative Ba7Nb4MoO20. In dry conditions, the conductivity of Ba7Nb4MoO20 is purely oxide ionic, with a wide electrolytic window of 10-18 < pO2 0.035. Variable temperature synchrotron and neutron diffraction studies confirm that there is no change in the crystal or magnetic structure at the insulator-insulator transition. Results from AC transport show that there are glassy dynamics at the transition. We propose that this is the first example of a “high temperature” superinsulator.

This talk is open to final year undergraduate project students, MSc students, PhD students, post-doctoral researchers and academic staff.