The high frequency properties and crystallization of PbTiO3 glass-ceramics by sol-gel process

PbTiO3 glass-ceramics were produced by a sol-gel process. DTA and X-ray diffraction analysis provided information about the structural transformations and crystallization temperature. The range of crystallization temperature of PbTiO3 is larger than that of PbTiO3 glass-ceramics. By increasing the glass composition, the crystallization temperature was increased. The phase transformation of PbTiO3 from the cubic to the tetragonal phase depends on the crystal size caused by the different heat treatment temperatures. The dielectric measurements in high frequency range (> 10(7) Hz) exhibited evidence of a relaxation phenomena near 850 MHz. With increasing glass composition, the position of the relaxation frequency was increased. The temperature dependence of the dielectric constant of PbTiO3 and PbTiO3 glass-ceramics has an obvious discrepancy. The dielectric constant of PbTiO3 glass-ceramics shows the characteristic dispersion at the Curie point. It indicated that the glass ceramic sample has a stronger tendency for a diffuse phase transition.