Controlled phase separation by an electric field in glasses

Externally applied electric field has a significant effect on phase separation of glasses. At low BaO contents, spherical barium-rich phase separation is promoted due to the greater (ε2/ε1>1) ratio of the dielectric constants of the new phases than the old. Increasing BaO contents to 0.1 mol%, owing to the interconnected phase separation produced, the electric field has no effect on the phase separation. At higher BaO contents, spherical silica-rich phase separation is retarded. This means that the electric field can either stimulate or inhibit the phase separation process. Furthermore, we may control phase separation of glasses. These results suggest a new method for the preparation of nanocrystalline glass ceramics.