Conditions Extrêmes et Matériaux : Haute Température et Irradiation

utilisateur non identifié  |   Login

View CEMHTI Publication

Return to publication search...
Ask for a reprint
email :  



A.Zandona, E.Chesneau, G.Helsch, A.Canizarès, J.Deubener, V.Montouillout, F.Fayon, M.Allix, 'Glass-forming ability and structural features of melt-quenched and gel-derived SiO2-TiO2 glasses', J. Non-Cryst. Solids 598 121967 (2022) doi:10.1016/j.jnoncrysol.2022.121967

SiO2-TiO2 glasses produced by aerodynamic levitation coupled to laser heating or by sol-gel spray-drying were compared to highlight their structural differences. Glass formation was possible by melt-quenching up to 10 mol% TiO2, while higher contents led to devitrification. Raman spectroscopy and solid-state 17O and 29Si magic-angle-spinning nuclear magnetic resonance confirmed the clear emergence of Ti-O-Si bonds and a tetrahedral oxygen coordination of Ti4+ leading to full network connectivity, as also substantiated by the synthesis of TiO2-doped cristobalite. In gel-derived glasses, water content induced partial network depolymerization, thereby enhancing the solubility of TiO2 in the hydrous silicate matrix. However, full dehydration during heating proved challenging due to a competing tendency towards devitrification: the glass-forming range in the anhydrous binary SiO2-TiO2 system does not therefore appear to be significantly enlarged by the sol-gel synthesis route.