Preparation of Bi₂O₃-B₂O₃-ZnO-BaO-SiO₂ glass powders with spherical shape by spray pyrolysis

Bi₂O₃-B₂O₃-ZnO-BaO-SiO₂ glass powders were firstly prepared by spray pyrolysis. Bi₂O₃-B₂O₃-ZnO-BaO-SiO₂ glass powders prepared by spray pyrolysis had complete spherical shape and micron size at the optimum preparation temperatures. One micron-sized glass powder was formed from one droplet by drying, decomposition and melting processes. The dielectric layers formed from the glass powders prepared by spray pyrolysis had clean surface, dense inner structure, and high transparencies. The maximum transparency of the dielectric layer formed from the glass powders obtained by spray pyrolysis was 89% at the firing temperature of 580 °C. The transparencies of the dielectric layers formed from the glass powders obtained by spray pyrolysis at preparation temperature of 1250 °C decreased from 90 to 67% when the firing temperatures of the layers were changed from 580 to 520 °C.