Silicon carbide composites (SiC) are under active consideration as a structural material in the blanket of future fusion reactors. In operation, they will be subjected to irradiation damage from 14 MeV neutrons which will cause significant levels of transmutation and very little is known about the effects impurities produced in this way will have on the engineering properties of SiC.
This project will use analytical electron microscopy, particularly the core-level spectra produced by the different elements, to study the transmutation product defects introduced to SiC specimens by ion implantation. The spectra are generated by the excitation of core electrons into the unoccupied states, and as such contain information about the bonding within a material. This information is often difficult to extract, and modelling can greatly aid the interpretation of experimental data as it is able to provide a link between a particular structural model and corresponding spectrum. In this project, likely impurity bonding environments will be determined using ab initio structure searching, with machine-learning potentials. Spectra simulated from those bonding environments via density-functional theory will then be used to interpret experiments. Based on the defect structures, their impact on functional properties such as thermal conductivity, dimensional swelling, electrical conductivity, and hydrogen isotope retention can be assessed.
Any questions concerning the project can be addressed to Prof Rebecca Nicholls (rebecca.nicholls@materials.ox.ac.uk) and Prof David Armstrong (david.armstrong@materials.ox.ac.uk).
General enquiries on how to apply can be made by e mail to graduate.studies@materials.ox.ac.uk. You must complete the standard Oxford University Application for Graduate Studies. Further information and an electronic copy of the application form can be found at https://www.ox.ac.uk/admissions/graduate/applying-to-oxford.
