Epitaxial stabilisation of uranium silicide line compounds

Epitaxial single crystal thin films of U3Si, U3Si5, α−USi2, and USi3, alongside poly-crystalline U3Si2 have all been synthesised using DC magnetron sputtering. These idealised samples provide the bases on which fundamental studies can be conducted for the understanding of advanced technology fuel (ATF) candidates: U3Si, U3Si2, and U3Si5. The silicon-rich phases, USi2 and USi3 are of interest as intermediate oxidation products, forming as a result of the surface oxidation of the fuel candidates. Films were characterised using x-ray diffraction (XRD), and x-ray photoelectron spectroscopy (XPS), with XRD results indicating the stabilisation of [001]-oriented surfaces for all epitaxial phases with the exception of hexagonal U3Si5, which was found to be [100]-oriented. The XPS area analysis results from the U-4f and Si-2s core levels indicate that all phases are stoichiometric within error.