Transparencies of dielectric layers formed from size-controlled Bi-based glass powders obtained by spray pyrolysis

Submicron-size Bi-based glass powders were directly prepared by high-temperature spray pyrolysis. The mean sizes of the Bi-based glass powders were changed from 0.48 to 0.91 μm by changing the concentrations of spray solution. The dielectric layers formed from the Bi-based glass powders with fine size had higher transparencies than those of the dielectric layers formed from the Bi-based glass powders with large size. The transparencies of the dielectric layers formed from the glass powders obtained by spray pyrolysis from spray solution of 0.05 M decreased from 94 to 67% when the firing temperatures of the dielectric layers were changed from 580 to 500 °C. At the same firing temperatures, the transparencies of the dielectric layers formed from the glass powders obtained by spray pyrolysis from spray solution of 0.5 M decreased from 83 to 28%. The dielectric layers formed from the glass powders with fine size had dense and homogeneous structures even at low firing temperatures.