Effect of preparation temperature on the characteristics of PbO–B2O3–SiO2 glass powders with spherical shape

PbO–B2O3–SiO2 powders were prepared using spray pyrolysis at different preparation temperatures. The characteristics of these glass powders were strongly affected by the preparation temperatures. The powders prepared at temperatures below 650 °C had non-spherical shapes, irregular morphologies, and aggregation between powders. One powder with a spherical shape and a dense morphology was obtained from one droplet at preparation temperatures between 700 and 1250 °C. Some of the powders evaporated at preparation temperatures above 1300 °C. The glass phase was formed during the spray pyrolysis even within a short residence time of the powders inside a hot wall reactor at a temperature of above 800 °C. Dielectric layers with clean surfaces and dense structures were achieved from the powders obtained at preparation temperatures above 600 °C. The dielectric layers formed from the powders prepared using spray pyrolysis at preparation temperatures above 600 °C had high similar transparencies regardless of their preparation temperatures.