​​Crystallography Group Leader


Steve completed his BSc. in Physics with Mathematics at University of Reading in 1981 and stayed at Reading under the supervision of Prof. Roger Stewart to complete a PhD. in Physics in 1985. His research studied the process of precipitation hardening in Al-Cu and Ni-Cr-Al based alloys, using small angle neutron scattering, indentation hardness and electrical resistance measurements. Steve then took up a Postdoctoral Researcher position, jointly held between the Clarendon Laboratory, University of Oxford and the Harwell Laboratory, UK Atomic Energy Authority. this project investigated the high temperature thermodynamic properties of nuclear fission fuels, focussing on neutron scattering studies of UO2 and structural analogues such as ThO2, ZrO2, SrCl2 and Li2O.

In 1988, Steve joined the ISIS Crystallography Group as Instrument Scientist on Polaris and was later responsible a major upgrade to the diffractometer, with funding of approximately £4M from the STFC Facility Development Scheme and the Swedish Research Council, Vetenskapsrådet. During his time at ISIS, Steve has established a research programme investigating structure-property relationships within ionically conducting solids. Initially, this work focussed on 'model' Ag+, Cu+ and F– superionic compounds, including the role of high pressure in promoting/hindering extensive ionic disorder. However, with the increased interest in materials for energy production and storage, the emphasis moved to more technologically relevant systems, such as H+ and O2- conductors for Solid Oxide Fuel Cell applications and Li+ conductors as potential electrode and electrolyte materials for lithium batteries. An important aspect of Steve's research programme has been the development of novel sample environment devices for in-situ neutron diffraction studies of the materials under conditions which mimic those found in their technological application.

In 2012 Steve became head of the ISIS Crystallography Group.

Visiting Positions

Visiting Professor in Neutron Scattering, Department of Materials Science and Engineering, University of Sheffield.

Research Interests

  • Structure-property relationships within solids possessing high ionic conductivities.

  • 'Model' superionic compounds (e.g. F–, Ag+ and Cu+ conductors).

  • H+ and O2- conductors for Solid Oxide Fuel Cell applications.

  • Li+ conductors for potential use as electrodes and electrolytes in lithium batteries.

  • Use of 'total scattering' methods to probe the short-range ion-ion correlations.

  • Development of new sample environment facilities for in-situ neutron powder diffraction studies.

  • Impedance spectroscopy and computer simulation methods, to complement neutron measurements.


  • Dr. Isaac Abrahams (Queen Mary London) and Prof. Franciszek Krok (Warsaw University). Oxide-ion conductors, including Bi2O3 based compounds.

  • Dr. Jordi Biendicho (CIEC Barcelona). Development of in-situ electrochemical cells for battery studies.

  • Prof. Sten Eriksson and Dr. Stefan Norberg (Chalmers University). Development of 'total scattering' methods, new sample environment devices and studies of H+ conductors.

  • Prof. David Keen (ISIS). Ag+ and Cu+ based superionics, including high pressure studies.

  • Prof. Paul Madden (Oxford University), Dr. Dario Marrocchelli (MIT Boston) and Prof. Graeme Watson (Trinity College Dublin). Molecular Dynamics studies of ZrO2 and CeO2 based solid electrolytes.

  • Dr. Chris Mohn (Oslo University). Ab-initio Molecular Dynamics studies of Bi2O3 based solid electrolytes.

  • Prof. Anthony Powell (Reading University) Assessing the potential use of ternary Cu+ conducting chalcogenides for thermoelectric applications.

  • Prof. Tony West (Sheffield University). Characterisation of new anode and cathode materials for lithium batteries.

Past Students

  • David Parfitt (Oxford-ISIS). 2004-2007. “High pressure studies of superionic conductors".

  • Erinc Engin (Heriot-Watt-ISIS). 2005-2008. “Development of simultaneous diffraction-conductance measurements at ISIS".

  • Xi Liu (Queen Mary London-ISIS). 2006-2010. “Characterisation of the defect structures in ionically conducting fluorites".

  • Dario Marrocchelli. (Edinburgh-ISIS). 2007-2010. “Defect structures and ionic conductivity of oxide solid electrolytes".

  • Helen Kitchen (Glasgow-ISIS). 2009-2013. “Time-resolved neutron diffraction: Ultra-rapid microwave synthesis in-situ".

  • Ben Corrie (Birmingham-ISIS). 2010-2013. “Structure-property relationships in new proton/oxide-ion conductors".

Current Students

  • Bo Dong (Sheffield-ISIS Joint PhD Student).

  • Sebastian Long (Reading-ISIS Joint PhD Student). 

  • Ali Shehu (Queen Mary London-ISIS Joint PhD Student). 


  • PI on STFC Facility Development grant proposal “An upgrade to the Polaris powder diffractometer at ISIS". 2006-2009. Funding of £3.0M for a major upgrade to the Polaris diffractometer.

  • Co-I on Swedish Research Council, Vetenskapsrådet (VR) grant proposal “Upgrade of the Polaris instrument and access to state-of-the-art neutron powder diffraction facilities at ISIS". 2007-2010. Awarded approximately £900k as an additional contribution to the Polaris upgrade project.

  • Co-I on Swedish VR grant “Upgrade of HRPD and access to state-of-the-art neutron facilities at ISIS". 2010-2013. Approximately £800k awarded to support an upgrade to HRPD and to develop novel sample environment equipment for in-situ studies of new materials for energy storage and generation.

  • Co-I on Swedish VR grant “Diffraction capability at the IMAT beamline and a continued Sweden-ISIS instrument collaboration". 2014-2018. Awarded £1.2M to fund the diffraction detectors on IMAT and to continue to support the ISIS-Sweden collaboration by, for example, funding joint Postdoctoral Researchers.

Committee Memberships

  • ISIS Representative, ISIS Facility Access Panel 1.

  • Member ESS Scientific and Technical Advisory Panel for Diffraction.


  • Development of In-situ Electrochemical Cells for Battery Studies. 

  • Development of an In-situ Cell for Studies of Thermoelectric Materials. ​

Selected Publications

  • P. Berastegui, S. Hull, F.J. Garcia-Garcia and S.G. Eriksson, “The crystal structures, microstructure and ionic conductivity of Ba2In2O5 and Ba(InxZr1-x)O3-x/2“, Journal of Solid State Chemistry, 164, 119-130 (2002).

  • J.M. Besson, R.J. Nelmes, G. Hamel, J.S. Loveday, G. Weill and S. Hull, “Neutron Powder Diffraction above 10GPa", Physica B, 180, 907-910 (1992).

  • J.P. Goff, W. Hayes, S. Hull, M.T. Hutchings and K.N. Clausen, “Defect structure of yttria-stabilized zirconia and its influence on the ionic conductivity at elevated temperatures", Physical Review B, 59, 14202-14219 (1999).

  • S. Hull, “Superionics: crystal structures and conduction processes", Reports on Progress in Physics, 67, 1233-1314 (2004).

  • S. Hull and D.A. Keen, “High-Pressure Polymorphism of the Copper(I) Halides – A Neutron-Diffraction Study to ~10 Gpa", Physical Review B, 50, 5868-5885 (1994).

  • S. Hull and D.A. Keen, “Pressure-induced phase transitions in AgCl, AgBr, and AgI", Physical Review B, 59, 750-761 (1999).

  • S. Hull, S.T. Norberg, I. Ahmed, S.G. Eriksson, D. Marrocchelli and P.A. Madden, “Oxygen vacancy ordering within anion-deficient Ceria", Journal of Solid State Chemistry, 182, 2815-2821 (2009).

  • S. Hull, R.I. Smith, W.I.F. David, A.C. Hannon, J. Mayers and R. Cywinski, “The Polaris Powder Diffractometer at ISIS", Physica B, 180, 1000-1002 (1992).

  • D.A. Keen, S. Hull, W. Hayes and N.J.G. Gardner, “Structural evidence for a past-ion transition in the high-pressure rocksalt phase of silver iodide", Physical Review Letters, 77, 4914-4917 (1996).

  • R.J. Nelmes, J.S. Loveday, R.M. Wilson, J.M. Besson, P. Pruzan, S. Klotz, G. Hamel and S. Hull, “Neutron-Diffraction Study of the Structure of Deuterated Ice-VIII to 10 Gpa", Physical Review Letters, 71, 1192-1195 (1993).