Hydrous barium disilicate glasses containing 2.75 and 3.54wt% of dissolved water (corresponding to a molar concentration of H atoms of 11.1 and 14.2mol/l, respectively) were synthesized by high-temperature fusion in an internally heated gas pressure vessel. Near-infrared spectroscopy gave evidence that both OH groups and H2O molecules were present in the glasses. The maximum intensity in the range of OH stretching vibrations was at 2800/cm indicating strong H bonding in the glasses. Electric conductivity measurements were carried out at up to 523K without significant alteration of the sample. At higher temperatures, OH groups were converted to molecular H2O and water diffuses out of the sample resulting in a continuous decrease of the conductivity. An activation energy of 87kJ/mol was derived for the direct-current conductivity in the unaltered glasses similar to the activation energy for bulk water diffusion in other silicate glasses. Because the dry barium disilicate glass was an electrical insulator at experimental conditions, it was deduced that the direct-current conductivity of the hydrous glasses was due to proton conduction.Proton Conduction in Glass – an Impedance and Infrared Spectroscopic Study of Hydrous BaSi2O5 Glass. H.Behrens, R.Kappes, P.Heitjans: Journal of Non-Crystalline Solids, 2002, 306[3], 271-81