Effect of electric field on the crystallization of lead titanate in a glass

An electric field was applied to a PbO-TiO2-Al2O3-SiO2 glass during the crystal nucleation treatment at 570degreesC in order to produce oriented glass-ceramics. After the crystallization treatment at 620degreesC of the nucleated glass, an enhanced a-axis preferred orientation of the lead titanate cubic perovskite, which is not ferroelectric, was developed in the surface-layer region. However, the a-axis orientation was difficult to develop in the interior region of the sample, possibly due to ion migration during the nucleation treatment. The degree of a-axis orientation on the as-heated surface showed a maximum at an optimum nucleating time t(max) and the t(max)-value decreased with an increase in the applied electric field strength. (C) 2004 Kluwer Academic Publishers.