Add to ORKGThe 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