By means of S-4200 SEM, phase separation of CaO-Al2O3-SiO2 glasses upon app
lication of an electric field is investigated. The experimental results sho
w that externally applied electric field promotes the phase separation of t
he glass, and it leads to a different size of the droplet phase. In the vic
inity of the anode of the glass, the smaller droplet phase is induced compa
red with the cathode of the glass. The accelerating phase separation of the
glass in the presence of an electric field is due to the decrease in the f
ree energy forming a critical nucleus size. The different size of the dropl
et phase of the cathode is due to the increase in the driving force of nucl
eation and decrease in the viscosity of the glass compared with that of the
anode of the specimen. (C) 1999 Kluwer Academic Publishers.