Characterization of oxyfluoride tellurite glasses through thermal, optical and ultrasonic measurements

A wide range glass system based on the TeO2-WO3-ZnF2 was prepared. A number of physical properties, namely, the glass transition temperature, optical energy gap, Urbach energy, optical basicity, ultrasonic velocity (longitudinal and shear), elastic moduli, Poisson's ratio and Debye temperature were investigated by using several techniques such as: differential thermal analysis, dilatometric, UV-NIR-IR spectra and pulse-echo. These glasses have a high transmission in the visible, the near infrared and infrared regions, very low OH-vibration absorption bands and high thermal stability beyond 169 deg. C. The results indicated that most properties are observed to be dependent on the ZnF2 content. These physical properties are reported with a view to drawing fluorotellurite optical fibres