Image

Solid-state Chemistry and Neutron Scattering: From Quantum Spin-Liquids to Liquid-Like Ionic Conductors

My core research interests are: making new solid-state compounds with interesting (hopefully useful) properties; and using neutron scattering techniques to understand how they work. This talk will focus on examples at opposite ends of the temperature scale. At very low temperatures, theoretically down to 0 K, magnetic ions with unpaired electron spins arranged in “frustrated” topologies such as triangles try but fail to find a long-range ordered ground state. This ideally leads to a Kitaev quantum spin-liquid state in which the spins continue to fluctuate so the compound has finite entropy at absolute zero. We study such materials with polarised magnetic total neutron scattering and inelastic neutron scattering. At very high temperatures, different sublattices of solid-state compounds can dissociate, with one (generally containing the lightest atoms) become liquid-like while the other remains solid, giving rise to fast ionic conduction. We study these cases using in situ neutron diffraction and quasielastic neutron scattering. All these experiments benefit greatly from ab initio (DFT) modelling of structure and dynamics to simulate and therefore help interpret the data. 

Biography

Chris Ling is a Professor in the School of Chemistry at the University of Sydney. He has particular interests in solid-state ionic conduction at high temperatures, and strongly-correlated electronic behaviour at low temperatures. His research in inorganic solid-state chemistry makes particular use of neutron and synchrotron X-ray scattering methods to characterise the structures and dynamics of new materials. Chris is currently Theme Leader for Functional Energy Materials in the School of Chemistry, Deputy Director of the Sydney Analytical Core Research Facility, and Chair of the IUCr Commission on Inorganic and Mineral Structures.