Relaxor characteristics of ferroelectric BaZr0.2Ti0.8O3 ceramics

The crystalline microstructure, surface morphology, and the dielectric properties of BaZr0.2Ti0.8O3 (BZT) ceramics are investigated. From the X-ray diffraction pattern, it is found that the c-axis lattice parameter of the BZT ceramics is greater than the a-axis one. The temperature dependence of the electric permittivity indicates that there exists a diffuse transition in BZT ceramics. According to a modified Curie-Weiss law, it is calculated that the diffuseness constant (?) equals 1.93. From the hysteresis loops, it is found that the remanent polarization (2Pr) and the coercive field (2EC) of BZT ceramics both increase as the applied maximum voltage increases.