PbO-B2O3-SiO2 glass powders were directly prepared by a alter expansion aerosol generator (FEAG) process. Glass powders were formed by melting and cooling processes of the powders inside the hot wall reactor which was maintained at a low pressure. The powders prepared at temperatures below 800 degrees C had a spherical shape and submicrometre size. One glass powder was formed from one droplet at preparation temperatures below 800 degrees C. On the other hand, the powders prepared at a temperature of 900 degrees C had a bimodal size distribution with nanometre and submicrometre size. The mean size of the glass powders prepared by the FEAG process at a temperature of 800 degrees C was 320 run. In the DSC curve, the glass transition temperature (T,) of the glass powders was 411.5 degrees C. The transparencies of the dielectric layers formed from the glass powders obtained by the FEAG process were higher than 90% within the visible tight range at annealing temperatures above 500 degrees C.

Keywords: glass powder; spray pyrolysis; dielectric material