Influence of processing conditions on the grain growth and electrical properties of barium zirconate titanate ferroelectric ceramics

In this study, structural, dielectric and ferroelectric properties of BaZr0.025Ti0.975O3 ferroelectric ceramics have been investigated. The compound was synthesized using solid state reaction technique. It is observed that the synthesized compound have perovskite crystal structure. As the sintering temperature increases from 1200 degrees C to 1250 degrees C and 1300 degrees C, the average grain size increases from 0.62 mu m to 2.82 mu m and 3.20 mu m respectively. Moreover, the domains with "water-mark" and "lamellar" features are observed in SEM micrographs. The dielectric measurements as a function of temperature show a decrease in Curie temperature on increasing the sintering temperature. The decrease in Curie temperature is attributed to the decreased tolerance factor of the perovskite ABO(3) structure. There is enormous increase in the permittivity with the increase in grain size. The coercive field decreases and the remanent polarization increases as the grain size increases. (C) 2011 Elsevier B.V. All rights reserved.