Correlation of grain size, phase transition and piezoelectric properties in Ba_0.85Ca_0.15Ti_0.90Zr_0.10O₃ceramics

Pb-free ceramics Ba0.85Ca0.15Ti0.90Zr0.10O3inspired by the excellent piezoelectricity of morphotropic phase boundary deriving from a tricritical point have been prepared by a solid state reaction route and the effects of grain size and room-temperature phases of the ceramics have been studied in detail. When sintering temperature rises from 1320 to 1560 °C with controlling the dwell time for 2 h, the ceramic sintered at 1480 °C possesses the optimum piezoelectricity. We choose 1360 and 1480 °C as two distinctive sintering temperatures to further study the effect of dwell time on the electrical properties of the ceramics. The results show that the improved piezoelectric behavior (d33 ~ 416 pC/N and kp ~ 55.8 %) is demonstrated for the Ba0.85Ca0.15Ti0.90Zr0.10O3ceramic at an optimal sintering temperature of 1480 °C and dwell time of 2 h, which is attributed to the largest grain size together with more noticeable rhombohedral–tetragonal phase transition near room-temperature.