Study of spectroscopic and thermal characterization of TeO2-Ga2O3 oxyfluoride (TGOF) glasses and glass-ceramics activated by Pr3+ ions. The role of phonons

The glasses based on TeO2-Ga2O3 system as a promising group of heavy metal oxide glasses have been subject of great attention in the aspect of optoelectronics applications because of good transparency in the mid-infrared up to 6-7 µm and the possibility to incorporate a large amount of RE ions. The paper presents thermal stability, the UV-VIS and IR transmission and luminescence spectroscopy of the gallium-tellurite oxyfluoride glass. The base gallium-tellurite glass 0.74TeO2·0.15Ga2O3 was modified by addition of 11 mol% BaF2 and 1 mol% Pr6O11. DTA/DSC data showed that the glasses are characterized by the multi-stage crystallization. The luminescence spectra have been registered at various temperatures and resulting characteristics allowed to draw conclusions on the role of phonons in their evolution at different temperatures. To interpretations a kinetic analysis and the Bose-Einstein statistics were employed.