Luminescence Properties of Oxyfluoride Glass and Glass-ceramic Doped with Y^3+ Ions

Oxyfluoride glass- ceramics containing CaF2 nano- crystals doped with Y3+ ions were prepared by onestep crystallization of SiO2- Al2O3- CaO- CaF2 glasses at different temperatures. X-ray diffraction (XRD) results have revealed that CaF2 was the only precipitated crystalline phase in glass- ceramic samples. According to the XRD results, a glass- ceramic was selected as the best sample in order to compare its optical properties with basic glass. Photoluminescence (PL) and UV-Vis spectra are utilized to check optical properties of glass and glass- ceramic samples. A broad emission band in the visible region was determined, which was stronger in the glassy sample. Scanning electron microscopy (SEM) observation and EDX (Energy-dispersive X-ray spectroscopy) results establish the doorway of Y^3+ ions into just some of the crystals embedded in the glassy matrix, that was the rational reason of photoluminescence intensity decrease in glass-ceramic.