Effects of Na2O additions on the thermal and optical properties of BaO-ZnO-B2O3-SiO2 glass powders prepared by spray pyrolysis

Abstract

Fine-sized BaO-ZnO-B2O3-SiO2 (BZBS) glass powders doped with various amount of Na2O were directly prepared by spray pyrolysis at a temperature of 1400℃. The BZBS glass powders prepared with low amounts of Na2O below 5.7 wt.% of the product had a glass structure with amorphous phases. The glass transition temperature (T g) of the BZBS glass powders was changed from 517.3 to 468℃ when the amount of Na2O added to the product was changed from 0 to 5.7 wt.%. Melting of the glass powders with 1.9 wt.% Na2O occurred at a temperature of 560℃. On the other hand, melting of the glass powders with 3.8 and 5.7 wt.% Na2O occurred at temperatures of 540 and 520℃, respectively. The dielectric layers formed from the glass powders with an amount of Na2O added below 5.7 wt.% of the product had high transparencies, above 80%, at a firing temperature of 580℃. The addition of Na2O to the glass powders improved the transparencies of the dielectric layers at low firing temperatures.