Thermal properties of boro-germanate glasses

Abstract Thermal properties of boro-germanate glasses varying with molar ratios B 2 O 3 /GeO 2 have been investigated. The glass transition temperature is reduced with increasing B 2 O 3 concentration suggesting a more open structure, which was also confirmed using the Raman spectroscopy. Based on DSC measurements, thermal stability parameters for glasses over a wide molar ratios B 2 O 3 /GeO 2 were determined. The experimental results indicated that boro-germanate glasses exhibit good thermal stability against devitrification suggesting their great potential in optical fiber manufacturing technology. Thermal treatment process of boro-germanate glasses doped with selected lanthanide ions has been also applied to fabricate glass–ceramic systems. Structural and optical changes in glass samples before and after thermal treatment were evidenced using the X-ray diffraction and luminescence spectroscopy. Systematic investigations well demonstrated that boro-germanate glasses belong to glass systems, which are more resistant to crystallization.