Structure, Glass Stability and Crystallization Activation Energy of SrO-CaO-B2O3-SiO2 glasses doped with TiO2

By the first time the correlation between glass stability (GS), activation energy for crystallization (E-c) and structural data was investigated for some TiO(2)doped CaO-SrO-B2O3-SiO2 glasses obtained from the same batch. B-11 NMR spectra demonstrated that the boron changes from tetragonal to trigonal configuration for TiO2 contents higher than 4 mol%, while the Si-29 NMR spectra showed the absence of Q(4) species, in addition to an increase in Q(2) at the expense of Q(3) units. Both observations are consistent with Ti acting as a network modifier. It was demonstrated that all these glasses crystallize mainly from the surface, and the crystal growth changes with the TiO2 content. Most of the GS parameters increase with the TiO2 content, while E-c decreases for larger TiO2 contents. This dramatic reduction in E-c is strongly correlated to the change in the role of Ti cation in the glass matrix.

Automated summary

The study revealed that the presence of TiO2 in the glass caused changes in the structure of boron and silicon, affecting the crystalline properties of the glass. As the TiO2 content increased, the glass stability parameters increased, while the activation energy for crystallization decreased.