Research Guides

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

"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.

"The indifference of superconductivity and magnetism to size-mismatched cations in the layered iron arsenides Ba_1−xNa_xFe₂As₂."
Cortes-Gil, R.; Parker, D. R.; Pitcher, M. J.; Hadermann, J.; Clarke, S. J. Chem. Mater. 2010, 22, 4304-4311.

"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.

"Stoichiometric CeOCuS – a well-behaved Ce(III) layered oxysulfide"
Pitcher, M. J.; Smura, C. F.; Clarke, S. J. Inorg. Chem. 2009, 48, 9054-9056.

"Structure, antiferromagnetism and superconductivity of the layered iron arsenide NaFeAs"
Parker, D. R.; Pitcher, M. J.; Baker, P. J.; Franke, I.; Lancaster, T.; Blundell, S. J.; Clarke, S. J. Chem. Commun. 2009, 2189-2191.

"Fragmentation of an infinite ZnO₂ square plane into discrete [ZnO₂]²⁻ linear units in the oxyselenide Ba₂ZnO₂Ag₂Se₂"
Herkelrath, S. J. C.; Saratovsky, I.; Hadermann, J.; Clarke, S. J. J. Am. Chem. Soc. 2008, 130, 14426-14427.

"Structure and superconductivity of LiFeAs"
Pitcher, M. J.; Parker, D. R.; Adamson, P.; Herkelrath, S. J. C.; Boothroyd, A. T.; Ibberson, R. M.; Brunelli, M; Clarke, S. J. Chem. Commun. 2008, 5918-5920.

"Layered oxysulfides Sr₂MnO₂Cu_2m-0.5S_m+1 (m = 1, 2, 3) as insertion hosts for Li-ion batteries."
Indris, S.; Cabana, J.; Rutt, O. J.; Clarke, S. J.; Grey, C. P. J. Am. Chem. Soc. 2006, 128, 13354-13355.