Journal of the American Ceramic Society, Vol.102, No.5, 2666-2674, 2019
Low sintering temperature for lead-free BiFeO3-BaTiO3 ceramics with high piezoelectric performance
Through modification of the heat-treatment process using a higher heating rate and a lower binder burnout temperature, the piezoelectric performance of water-quenched 0.67Bi(1.05)FeO(3)-0.33BaTiO(3) (BF33BT) lead-free piezoelectric ceramics was improved. The observed physical properties of BF33BT ceramics were very sensitive to the process temperatures. The sintering temperature (T-S) was changed within a narrow temperature range, and its effects were investigated. The largest rhombohedral distortion (90 degrees-alpha(R) = 0.14 degrees) and tetragonality (c(T)/a(T) = 1.022) were observed for the ceramic sintered at 980 degrees C, and its Curie temperature was 476 degrees C. This ceramic showed good piezoelectric properties and large grains; the piezoelectric sensor charge coefficient (d(33)) was 352 pC/N, and the piezoelectric actuator charge coefficient (d33*) was 270 pm/V. The high piezoelectric performance and low T-S of BF33BT ceramics indicate their potential as new low-cost eco-friendly lead-free piezoceramics.