Influence of sintering temperatures on the electrical property of bismuth sodium titanate based piezoelectric ceramics

A systematic investigation of cerium and stannum doped 0.94(Bi _0.5Na_0.5)TiO₃-0.06BaTiO₃ (Sn&Ce-BNT6BT) based lead-free piezoelectric ceramics is undertaken to understand the influence of sintering temperature on electrical properties. The X-ray diffraction patterns showed that all of the Sn&Ce-BNT6BT ceramics exhibited a single perovskite structure with the co-existence of the rhombohedral and tetragonal phase. The smaller grain size of Sn&Ce-BNT6BT ceramics was obtained at lower sintering temperature, and more cubical grains of Sn&Ce-BNT6BT ceramics were obtained at higher sintering temperature. The temperature dependence of dielectric permittivity of the compositions exhibited strong dispersion with the increasing temperature, and the dielectric loss tangent increased dramatically while the temperature over 225°C. The depolarization temperature T _d of Sn&Ce-BNT6BT ceramics sintered at 1160°C was 92.6°C. The remnant polarizations P _r for Sn&Ce-BNT6BT ceramics sintered at 1120 and 1200°C were found to be 28.8 and 33.4 μC/cm² at room temperature, respectively.