Characteristics of nano-sized pb-based glass powders by high temperature spray pyrolysis method

In this study, nano-sized PbO-B₂O₃-SiO₂ glass powders were directly prepared by high temperature flame spray pyrolysis. Glass powders prepared at a low flow rate of fuel gas had bimodal size distributions of nano-sized and submicron-sized powders. However, nano-sized glass powders with a narrow size distribution were prepared via a chemical vapor deposition (CVD) process at a high flow rate of fuel gas as 4.5 L/min. The mean size of the glass powders formed by the CVD process was 38 nm. Nano-sized glass powders were found to have high transmittances above 83% at sintering temperatures between 480 and 520°C. On the other hand, transmittances of the dielectric layers formed from the glass powders with bimodal size distributions of nano- and submicron-sized powders decreased with a decrease of sintering temperatures. The dielectric layers formed from the nano-sized glass powders had a dense structure with no porous areas inside the layer at low sintering temperatures.