Relaxor phenomenon of (1-x)(Ba.85Ca.15)(Zr.09Ti.91)O3-xTa + 0.6 wt% Li2CO3 ceramics with high piezoelectric constant and Curie temperature

In the work, Ta2O5 doped (Ba.85Ca.15)(Zr.09Ti.91)O3 + 0.6 wt% Li2CO3 ceramics were successfully fabricated by the conventional solid state sintering method. Piezoelectric performance of the ceramics was significantly enhanced by doping the tantalum oxide, the optimum properties were obtained at x = 0.04 wt%, (d33~326 pC/N, kp~63% and Tc~129 °C, respectively). The Tc drastically increased compared with previous results. Besides, the microstructure, dielectric and ferroelectric properties were carefully investigated. The temperature-dependent dielectric performance of the specimens exhibits obvious relaxor phenomenon under various frequencies. The relaxor characteristics and XRD were systematically discussed, which certified that the samples were relaxor ferroelectrics with a small dielectric loss (0.62%) and a large dielectric constant (13693).