Glass-forming ability and structural features of melt-quenched and gel-derived SiO2-TiO2 glasses

Alessio Zandonà (1) , Erwan Chesneau (1) , Gundula Helsch (2) , Aurélien Canizarès (1) , Joachim Deubener (2) , Valérie Montouillout (1) , Franck Fayon (1) , Mathieu Allix (1)

1 CEMHTI - Conditions Extrêmes et Matériaux : Haute Température et Irradiation
2 Institute of Non-Metallic Materials [Clausthal-Zellerfeld]

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 17 O and 29 Si magic-angle-spinning nuclear magnetic resonance confirmed the clear emergence of Ti-O-Si bonds and a tetrahedral oxygen coordination of Ti 4+ 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.

Mots clés: glass-forming ability; Raman spectroscopy; solid-state NMR; titania silica glasses; cristobalite

Domaines: Chimie inorganique; Matériaux

Alessio Zandonà, Erwan Chesneau, Gundula Helsch, Aurélien Canizarès, Joachim Deubener, et al.. Glass-forming ability and structural features of melt-quenched and gel-derived SiO2-TiO2 glasses. Journal of Non-Crystalline Solids, 2022, 598, pp.121967. ⟨10.1016/j.jnoncrysol.2022.121967⟩. ⟨hal-03874481⟩