- Structure analysis of nanocrystals and nanowires
- Surface structure determination by CTR and GISAXS
- Phase contrast imaging using hard X-rays
- X-ray diffraction methods development
My specialisation is X-ray diffraction using synchrotron radiation. During my 11 Bell-Labs years, I developed the methods for studying surface structure using X-ray diffraction. These methods, based on crystal truncation rods, have become the definitive technique for the determination of the atomic positions at surfaces and interfaces. These surface methods are still used today at the major SR facilities, NSLS (Brookhaven), ESRF (Grenoble), Spring8 (Osaka), APS(Chicago) and SLS (Villgen). More recently I have been developing method of using the very high coherence of the latest SR sources to enable direct 3D imaging of structure. This is potentially useful for examining strain distributions inside complex materials.
When I became Professor of Physics at the University of Illinois (Urbana) I started developing the coherent X-ray diffraction methods. These will expand further at the new Diamond Light Source (DLS) located at Rutherford Lab near Oxford. My current research at UCL is largely focused on this development, although we continue to do experiments at SLS, ESRF and APS during the buildup period.