Influence of titanium dioxide concentration on thermal properties of germanate-based glasses

Influence of titanium dioxide concentration on thermal properties of germanate-based glasses has been studied. Germanate glasses varying with TiO₂ content were examined using DSC methods. The DSC curves exhibit two exothermic peaks, when GeO₂ is substituted by TiO₂. Based on DSC measurements, characteristic temperatures were determined. The studies demonstrate that glass transition temperature increases, whereas thermal stability parameters are reduced with increasing TiO₂ concentration. The DSC curves were also acquired with different heating rates, and the Kissinger method was used to calculate the activation energy. X-ray diffraction analysis for germanate-based glass with TiO₂ indicates that crystallization processes are more complex and several phases are formed during annealing. The absorption and emission spectra of glass samples doped with Er³⁺ ions were also examined before and after annealing process.