Enhanced Thermostability, Thermo-Optics, and Thermomechanical Properties of Barium Gallo-Germanium Oxyfluoride Glasses and Glass-Ceramics
Résumé
Serial substitutions of BaF2 for BaO in BaO-Ga2O3-GeO2 glasses were performed, and the effects of the substitutions on the glass properties were investigated. The glass transition temperature, density, refractive index, thermo-optics coefficient, and figure of merit for thermal shock decreased with the replacement of oxygen by fluorine. On the other hand, the glass-forming ability increased. Fluorine substitution removed the absorption band of hydroxyl near 2.9 μm. Raman scattering spectroscopy was used to characterize the fluorogermanate glasses. The crystallization process of the glass-ceramics under different heat-treatment conditions was also investigated using differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, and atomic force microscopy. The thermal and mechanical properties were improved by controlling the crystal size of the near- and middle-infrared transparent glass-ceramics.