Effects of grain size on domain structure and ferroelectric properties of barium zirconate titanate ceramics

Barium zirconate titanate (BaZr0.2Ti0.8O3, Short for BZT) ceramics were prepared by conventional ceramic method, and the effect of grain size on domain structure and ferroelectric properties were studied by XRD, scanning electron microscopy (SEM) and LC material analyzer. It is found that BaZr0.2Ti0.8O3 ceramics is of perovskite crystal structure. As the sintering time increased from 0.5 h to 2 h, 4 h and 8 h, the average grain size of BZT ceramics increased from similar to 25 mu m to similar to 40 mu m, similar to 45 mu m and similar to 80 mu m. It is shown that the grain size influences on the types of domains of BaZr0.2Ti0.8O3 ceramics, and 90 degrees-domain has not been observed in large grain size sample. Moreover, domains with herribone, lamellar and "water-mark" characters are observed. The coercive electric field decreases and the remanent polarization increases as the grain size of BZT ceramics increases. (C) 2009 Elsevier B.V. All rights reserved.