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

Research data for Manuscript submission with title

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

Abstract

SiO2-TiO2 glasses produced by melt-quenching or 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 MAS NMR 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 the competing devitrification tendency: 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.