I’m interested in the effect of defects on material properties, ranging from single atom defects, such as vacancies and interstitials, to extended defects, such as dislocations, to macroscopic defects, for example cracks and voids. In my group we develop new tools to probe the structure of these defects and new approaches for measuring the changes in material properties they bring about. We then use experimental measurements to inform simulations aiming to capture defect-induced changes. The long-term goal is to be able to engineer defects and hence optimise material function and properties.
At X-ray wavelength we use micro-diffraction approaches to study lattice orientation and strain within crystalline objects at the nano-scale. In particular we’re interested in the use of coherent X-ray diffraction for the full field measurement of lattice distortions in nano-crystals. Scattering of visible light can be used as useful model system to further develop many of these X-ray techniques. At visible wavelengths we’re also interested in the use of transient grating techniques for probing elastic and thermal transport properties at the micro-scale.
Much of my recent work has concentrated on defects cause by irradiation of structural materials for future fusion reactors. Here, together with colleagues from the Culham Centre for Fusion Energy and the Oxford Department of Materials, we are trying to understand the formation of irradiation damage, its evolution over time, and how it changes mechanical and physical material properties. Other recent projects have centred on the failure of piezoelectric materials, as well as deformation-induced damage in biological materials.