You are here

BIMR Seminar Series - Michael Hayward - Oxford - UK

Event Date: 
Monday, May 1, 2017 - 3:30pm to 5:00pm

Title: Topochemical Reduction and Anion Exchange as a Route to Novel Electronic Materials

Abstract: Transition-metal oxides are the subject of intensive study due to the wide variety of physical and chemical properties they can exhibit. However, the search for new transition-metal oxides is hampered by the refractory nature of metal oxides, which requires the majority of synthesis approaches to operate at high temperature under thermodynamic control, precluding the preparation of metastable phases and thus limiting the variety of compounds that can be prepared. The topochemical (structure conserving) manipulation of complex oxides offers access to metastable phases by exploiting the small differences in the low-temperature mobility of the different species in extended oxide lattices. For example, in many complex metal-oxide lattices the oxide anions are more mobile than the cations at low temperatures. Thus, if the correct reagents are used, oxide anions can be removed, inserted or exchanged, while the cation framework remains largely unchanged, allowing the preparation of phases which cannot be synthesised by conventional high-temperature routes. Binary metal hydrides can act as highly effective reducing agents for the extraction of oxide anions from complex transition metal oxides, allowing the preparation of novel phases containing transition metal centres in unusually low oxidations state and/or unusual coordination environments. By applying these reagents to complex oxides containing heavy transition metals, novel phases containing 4d or 5d transition metals (Ru, Rh, Ir) in extremely low oxidation states, can be prepared and their electronic interactions studied.

Bio: Michael Hayward completed his D.Phil. in Oxford under the supervision of Prof. M. J. Rosseinsky. After completing a period of post-doctoral research with Prof. R. J. Cava at Princeton University he returned to Oxford, initially as a Royal Society University Research Fellow and is now a Professor of Inorganic Chemistry and Fellow of Somerville College.

Event Location: 
Location Details: