I grew up in Hertfordshire and was an undergraduate at St John’s College, Oxford and then a graduate student with Andrew Harrison and Matt Rosseinsky. I spent two years with Frank DiSalvo at Cornell University as a NATO Fellow before returning to Oxford as a Lloyd’s of London Tercentenary Foundation Fellow and a Junior Research Fellow at St Hugh’s College. I then spent two years as a University Lecturer at the University of Exeter before returning to Oxford as a University Lecturer in 2000. I became a Professor of Chemistry in 2014.


My research group focuses on solid-state synthesis and properties of classes of crystalline solid (you could call them “synthetic minerals”) that could have important technological applications as superconductors, ferromagnets, thermoelectric materials or battery electrodes or electrolytes. Current projects include detailed examination of the correlation of composition, crystal structure and physical properties of iron-based high-temperature superconductors, in particular, iron selenides with superconducting transition temperatures as high as 45 Kelvin, and investigation of the control using chemistry of the structure and physical properties of a series of layered transition metal oxide sulfides and selenides.

The group specialises in a range of solid state synthetic techniques and characterises new materials using X-ray and neutron diffraction measurements (including following chemical reactions in real time), magnetometry, transport measurements and X-ray absorption spectroscopy. A large part of the work is collaborative: we work particularly with Stephen Blundell and Andrew Boothroyd in Oxford Physics, Clare Grey at Cambridge University, Joke Hadermann at the University of Antwerp and with colleagues at international facilities such as the nearby Diamond Light Source and the ISIS pulsed neutron and muon facility.


At Exeter I teach almost all the topics in Inorganic Chemistry seeking to emphasise how the trends in the properties of the elements across and down the periodic table determine the chemistry of solids and molecules

I lecture mainly on solid state chemistry – understanding crystal structures, bonding and electronic properties of solids and how they are related.

Selected Publications

Synthesis and Magnetic Structure of the Layered Manganese Oxide Selenide Sr2MnO2Ag1.5Se2 Blandy, J. N.; Boskovic, J. C.; Clarke, S. J. J. Solid State Chem. 2017, 245, 61–66.

The Parent Li(OH)FeSe Phase of Lithium Iron Hydroxide Selenide Superconductors. Woodruff, D. N.; Schild, F.; Topping, C. V.; Cassidy, S. J.; Blandy, J. N.; Blundell, S. J.; Thompson, A. L.; Clarke, S. J. Inorg. Chem., 2016, 55, 9886–9891.

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  1958–1964.

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 Mat. 2015, 3, 041520.

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.