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

摘要

Barium zirconate titanate (BaZr_(0.2)Ti_(0.8)O_3, 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 BaZr_(0.2)Ti_(0.8)O_3 ceramics is of perovskite crystal structure. As the sintering time increased from 0.5 h to 2h,4h and 8h, the average grain size of BZT ceramics increased from approx 25 mu m to approx 40 mu m, approx 45 mu m and approx 80 mu m. It is shown that the grain size influences on the types of domains of BaZr_(0.2)Ti_(0.8)O_3 ceramics, and 90 deg -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.