The non-isothermal devitrification of Li2O·TiO2·6GeO2 glass

The effect of a partial replacing of GeO₂ by TiO₂ structure and non-isothermal devitrification of lithium heptagermanate glass, examined by Fourier transform infrared spectra, differential thermal analysis and X-ray diffraction, is reported and discussed. The structure and the glass-transition temperature are not affected by the substitution of GeO₂ by TiO₂ but the investigated glass, unlike lithium heptagermanate glass, devitrifies only from the surface into a crystalline phase isomorphous with Li₂Ge₇O₁₅ crystals. The validity of the Arrhenius-type relationship between the rate constant of crystal growth and the absolute temperature is also discussed.