Skip to main navigationSkip to main content
The University of Southampton

OXYGEN IN OXIDES: an inert packing atom, or does it have a life of its own? Seminar

2 February 2015
Building 29, Room 2075 Chemistry University of Southampton Southampton SO17 1BJ

For more information regarding this seminar, please email Nuria Garcia-Araez at .

Event details

Tony West presents a seminar at a joint event hosted by the Electrochemistry research group and the Functional Inorganic, Materials and Supramolecular chemistry research group.

We are accustomed to regarding oxygen in oxide structures as being present as the O2- ion, or at least, in the (-II) oxidation state. There are a few examples known of peroxides and superoxides, with oxidation states of (-I) and (-0.5), respectively, but usually the oxidation state is fixed and, for instance, oxygen is not regarded as redox-active. This talk will consider why oxides are built of O(-II) ions, since the O(-II) ion is spontaneously unstable in the gas phase, and therefore, the circumstances under which ionisation may occur. Experimental results will be presented showing how (i) hole conductivity in certain perovskite ceramics may be associated with ionisation of O(-II) ions, leading to (ii) insulator – semiconductor transitions in certain cases, (iii) a novel mechanism for resistive switching and possible memristive applications and (iv) the onset of electronic conductivity in materials such as yttria-stabilised zirconia, the archetypal oxide ion conductor that is used as the solid electrolyte in solid oxide fuel cells, in part due to the absence of any electronic conductivity. Finally, suggestions will be made as to (v) the possible occurrence and significance of redox-active oxygen as a component of lithium battery cathodes and (vi) the source of metallic conductivity associated with 2D electron gases in interlayer structures formed between insulators such as LaAlO3 and SrTiO3

Speaker information

Tony West, University of Sheffield. Tony West is Professor of Electroceramics and Solid State Chemistry at the University of Sheffield, Department of Materials Science & Engineering. He did his undergraduate degree in Chemistry at Swansea, a PhD degree in silicate chemistry at Aberdeen and then gained an academic position at Aberdeen, rising through the ranks to become Professor of Chemistry, before moving to Sheffield in 1999. He has received numerous prizes including the John B Goodenough Award in Materials Chemistry from the RSC in 2013, is a past president of the Inorganic Chemistry Division of IUPAC and was founding editor of the Journal of Materials Chemistry.

Privacy Settings