Influence of fluorine on thermal properties of lead oxyfluoride glass.

Oxyfluoride glasses are the basic materials for obtaining transparent glass-ceramic (TGC) which can be used in a wide range of optoelectronics devices such as: amplifiers, up-conversion, telescopes, laser sources. Oxyfluoride TGC is obtained by the control heat treatment of the parent glass due to low phonon nanocrystalline phases. The oxyfluoride glasses from the sodium-lead-silica system were the object of investigation. The influence of fluoride content on the thermal properties of glasses was analyzed. Thermal characteristics of glasses like the transition temperature T, the temperature for the crystallization onset T, and the maximum crystallization temperature T, thermal stability parameter were determined by DTA/DSC method. The linear expansion coefficients of oxyfluoride glasses as a function of temperature were measured using a thermo-mechanical analyzer (TMA 7 Perkin-Elmer). The effect of crystallization on the thermal expansion coefficient and softening temperature T was found. [ABSTRACT FROM AUTHOR]