Controlled crystallization in lead zirconate titanate glass-ceramics prepared by the sol-gel process

Lead titanate and lead zirconate titanate grains were grown in situ from lead-titanium-boron-silicon and lead-zirconium-titanium-boron-silicon gels prepared via the sol-gel method. The lead zirconate titanate grains were much smaller and more uniform than lead titanate grains grown from gels of similar composition. The crystallization mechanisms of the two systems were studied via scanning electron microscopy, X-ray diffractometry, Raman spectroscopy, and differential thermal analysis. Crystallization had a tendency to begin near the surface or at defects in the lead titanate system, whereas it was controlled by the original precipitated nuclei of tetragonal zirconia particles in the lead zirconate titanate system. Controlled bulk crystallization may explain the finer structure of the resultant lead zirconate titanate glass-ceramic.