Measurements of surface dynamics with application to rate theories

The project will utilise the Cambridge helium-3 spin-echo spectrometer (He3SE) to study diffusion and dynamics of atoms and molecules on surfaces. The aim will be to investigate new systems and further develop the understanding of sub-nanosecond and atomic-lengthscale diffusion, which the He3SE machine is uniquely capable of doing. For example, the start of the project has been devoted to measuring the diffusion of low-coverage oxygen on a ruthenium surface, a system which has applications in catalysis; it also presents an exciting opportunity to investigate the role of attractive interactions in surface diffusion, which is much less well-understood than simple repulsion, as oxygen has been observed to cluster even at low coverages. Further computational and theoretical work will be required to interpret the results, via Monte-Carlo and molecular dynamics simulations as well as analytic approaches to the problem. The project is also expected to include experimental and/or theoretical studies of rate theory applied to surfaces as well as further work on the role of interactions.