Research Guides

Department of Chemistry University of Oxford

Professor Simon Clarke

The synthesis, structures, chemistry and physical properties of new solids.

Our aim is to synthesise new solid state compounds and correlate their chemical and physical properties with their compositions and crystal structures. Many technological developments are driven by the discovery of solids with particular magnetic, electronic or chemical properties. The compounds we make may also be desirable model materials with which to test theories in condensed matter physics.

We work on non-oxide or multi-anion compounds which offer contrasting and complementary properties to the better-studied oxides. We synthesise new compounds using a range of methods, measure their crystal structures and physical properties and feed the results back into the synthetic programme.

Versatility in metal oxychalcogenides

Members of an homologous series of layered oxychalcogenides in which transition metal oxide layers are separated by metal sulfide layers exhibit unusual magnetic properties and are also of interest as potential Li-ion battery materials.

Iron-based superconductors

New high temperature superconductors based on iron arsenide, phosphide or selenide layers were discovered serendipitously in 2007/8. We have been engaged in a vigorous collaboration with colleagues in Oxford Physics to make new examples of these materials and understand their physical properties.

Further details of these and other projects may be found in the research section of the group's webpages

"Soft chemical control of the crystal and magnetic structure of a layered mixed valent manganite oxide sulfide."
Blandy, J. N.; Abakumov, A. M.; Christensen, K. E.; Hadermann, J.; Adamson, P.; Cassidy, S. J.; Ramos, S.;  Free, D. G.; Cohen, H.; Woodruff, D. N.; Thompson, A. L.; Clarke, S. J. APL Materials. 2015, 3, 041520.

"Soft chemical control of superconductivity in lithium iron selenide hydroxides Li1–xFex(OH)Fe1–ySe."
Sun, H.; Woodruff, D. N.; Cassidy, S. J.; Allcroft, G. M.; Sedlmaier, S. J.; Thompson, A. L.; Bingham, P. A.; Forder, S. D.; Cartenet, S.; Mary, N.; Ramos, S.; Foronda, F. R.; Williams, B. H.; Li, X.; Blundell, S. J.; Clarke, S. J. Inorg. Chem. 2015, 54, 1958.

"Ammonia-rich high temperature superconducting intercalates of iron selenide revealed through time-resolved in-situ X-ray and neutron diffraction."
Sedlmaier, S. J.; Cassidy, S. J.; Morris, R.; Drakopoulos, M.; Reinhard, C.; Moorhouse, S. J.; O'Hare, D.; Manuel, P.; Khalyavin, D.; Clarke, S. J. J. Am. Chem. Soc. 2014 136, 630-633.

"Enhancement of the superconducting transition temperature of FeSe by intercalation of a molecular spacer layer."
Burrard-Lucas, M.; Free, D. G.; Sedlmaier, S. J.; Wright, J. D.; Cassidy, S. J.; Hara, Y.; Corkett, A. J.; Lancaster, T.; Baker, P. J.; Blundell, S. J.; Clarke, S. J. Nature Materials 2013, 12, 15-19.

"Competing magnetic structures and the evolution of copper ion/vacancy ordering with composition in the manganite oxide chalcogenides Sr2MnO2Cu1.5 (S1−xSex)2."
Adamson, P.; Hadermann, J.; Smura, C. F.; Rutt, O. J.; Hyett, G.; Free, D. G.; Clarke, S. J. Chem. Mater. 2012, 24, 2802–2816.

"Compositional control of the superconducting properties of LiFeAs."
Pitcher, M. J.; Lancaster, T.; Wright, J. D.; Franke, I.; Steele, A. J.; Baker, P. J.; Pratt, F. L.; Trevelyan Thomas, W.; Parker, D. R.; Blundell, S. J.; Clarke, S. J. J. Am. Chem. Soc. 2010, 132, 10467-10476.

"Control of the Competition between a Magnetic Phase and a superconducting Phase in Cobalt-Doped and Nickel-Doped NaFeAs Using Electron Count"
Parker, D. R.; Smith, M. J. P.; Lancaster, T.; Steele, A. J.; Franke, I.; Baker, P. J.; Pratt, F. L.; Pitcher, M. J.; Blundell, S. J.; Clarke, S. J. Phys. Rev. Lett. 2010, 104, 057007.