Grain size effect on the poling of soft Pb(Zr,Ti)O3 ferroelectric ceramics

The properties of piezoelectric ceramic materials are strongly dependent on the degree of polarization as set by the poling process. As the polarization depends on the domain wall mobility, which in turn depends on the domain size and grain size, the current study focuses on the effect of the grain size on the poling process and dielectric and piezoelectric properties. Polarization and pyroelectric, dielectric and piezoelectric properties of modified donor doped ferroelectric Pb(Zr,Ti)O3 ceramics having different grain sizes have been studied. The dielectric and piezoelectric parameters greatly improved at room temperature with increasing grain size. The Curie temperature (160 °C) is found to shift slightly (by about 7 °C) towards higher temperatures as the grain size increases (2–10 μm). It is concluded that, an optimum choice of a combination of poling field and grain size leads to optimum physical properties. A limited dependence of the dielectric properties on the grain size in non-poled state exists. The dominant contribution to the dielectric properties in the different conditions of the material is discussed.