Phase transitions in sol-gel derived Eu-doped PZT ceramics

Abstract

Polycrystalline samples of Pb1-z Eu z (Zr0.60Ti0.40)1-z/4O3 (z = 0.07, 0.08 and 0.10) (abbreviated as PEZT) were prepared through the metal-alkoxide sol-gel route. X-ray diffraction analysis indicates that the PEZT compounds (nearly single phase) or solid-solution can be formed at 500°C through this route. The pellet samples sintered at 1300°C for 7 h have high density. SEM study shows the uniform distribution of spherical grains on the sample surface. Detailed dielectric studies of the compounds as a function of temperature (30–450°C) at two frequencies (103 and 104Hz) show that the broadening of the permittivity peak and transition temperature depend on Eu-ion concentration. Analysis of diffusivity (γ) of the dielectric peaks of the crystals provides its value between 1 and 2, indicating the different degrees of substitution disordering in the system. The values of remanent polarisation and coercive field decrease with increase in Eu concentration.