Published online by Cambridge University Press: 18 March 2013
Fe K edge X-ray absorption (XAS) and Fourier Transform Infra-Red (FT-IR) spectroscopies have been used to study potential structural modifications in sodium borosilicate glasses as a consequence of Kr+ irradiation. Glasses were doped with simulant waste elements and irradiated at room temperature with 450 keV Kr+ ions to a fluence of 2x1015 Kr+ ions cm-1. According to SRIM calculations, a damaged surface region approximately 400nm wide was produced. In order to probe only the damaged surface layer, XAS measurements were taken in total electron yield mode and FT-IR spectroscopy was conducted in reflectance off the glass surface. No change in Fe valence state was detected by XAS following irradiation. Reflectance FT-IR data revealed a shift to higher wavenumbers in the absorption bands located between 850 and 1100 cm-1 in the doped glasses, corresponding to bond stretching in the silicate network. Deconvolution of FT-IR spectra revealed the shift was due to polymerisation of the silicate network. Network connectivity was found to decrease in the un-doped glass, following irradiation. The results suggest an increase in silicate network connectivity by a cation mediated process, and demonstrates the successful application of surface sensitive XAS and FT-IR to the investigation of ion beam induced damage in amorphous materials.