Preparation and Characterization of Na_2O-Y_2O_3-P_2O_5-SiO_2 Transparent Glass Ceramics

摘要

Transparent glass ceramics containing Na_(3.6)Y_(1.8)(PO_4)_3 crystals were successfully synthesized using high temperature melting quenching and subsequent heat treatment of the precursor glass with a composition 15Na_2CO_3-3Y_2O_3-45SiO_2-31H_3BO_3- 5.4P_2O_5-0.6Sb_2O_3 (mol%). The impact of heat treatment is investigated in detail. The glass sample was tested by differential scanning calorimetry analysis to determine the heat treatment system. The ideal heat-treated condition is at 650°C for 2 h. The structure and morphology properties were systematically analyzed by recording X-ray diffraction patterns and scanning electron microscopy images, which indicate that Na_(3.6)Y_(1.8)(PO_4)_3 crystal were precipitated homogeneously among the glass matrix. The microstructural of precursor glass and glass ceramic were compared by analyzing FTIR spectra, indicating the formation of phosphate groups in glass ceramic. The refractive index of glass ceramics samples were measured. In the visible region, the transmittance of glass ceramics is up to 85%. Moreover, the relationship between the refractive index of the sample and the transmittance is discussed.