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 0.67Bi1.05FeO3‐0.33BaTiO3 (BF33BT) lead‐free piezoelectric ceramics was improved. The observed physical properties of BF33BT ceramics were very sensitive to the process temperatures. The sintering temperature (TS) was changed within a narrow temperature range, and its effects were investigated. The largest rhombohedral distortion (90°‐αR = 0.14°) and tetragonality (cT/aT = 1.022) were observed for the ceramic sintered at 980°C, and its Curie temperature was 476°C. This ceramic showed good piezoelectric properties and large grains; the piezoelectric sensor charge coefficient (d33) was 352 pC/N, and the piezoelectric actuator charge coefficient (d33∗) was 270 pm/V. The high piezoelectric performance and low TS of BF33BT ceramics indicate their potential as new low‐cost eco‐friendly lead‐free piezoceramics. Lead‐free piezoelectric performance; relationship among sintering temperature, piezoelectric coefficient, and Curie temperature.