Infrared and structural analyses of uranium oxidation products: preliminary results

Water vapor oxidation of uranium follows a cyclic process: (1) rapid oxidation to form a thin dense, adherent layer of uranium dioxide, (2) slow diffusion of H/sub 2/O and H/sub 2/ through this oxide, until (3) a thickness of 0.2 to 0.3 nm is achieved in a strained state that (4) relaxes from the surface allowing further (1) contiguous oxide formation and finally (5) the shards of oxide comprised of oxide laminae spall completely free of the metal surface. The oxide thus formed is hydrated on the surface. Diffuse reflectance infrared Fourier transform spectroscopy shows that these are several distinct modes of water binding delineated with respect to energetics and reversibility. Scanning electron microscopy aids immensely in defining the nature of the laminae. Implications and suggestions for further work are given to aid in a better understanding of corrosion processes.