Materials Science & Engineering, Tabriz University
Oxyfluoride glass ceramics containing CaF2nano-crystals doped with Y3+ ions were prepared by one-step 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 have been employed to study optical properties of glass and glass ceramic samples. A broad band emission in the visible region was observed, which was stronger in the glassy sample. Scanning electron microscopy (SEM) observation and EDX (Energy-dispersive X-ray spectroscopy) results proved the entrance of Y3+ ions into only some of the crystals embedded in the glassy matrix, which was the rational reason of photoluminescence intensity decrease in glass ceramic.