Reduced leakage current and excellent thermal stability in lead-free BiFeO₃–BaTiO₃-based piezoelectric ceramics.

Bai, Xudong; Pan, Yongqi; Xia, Zhichao; He, Caiwang; Li, Guannan; Chen, Yi

It is extremely difficult to completely pole BiFeO3–BaTiO3 ceramics, due to the large leakage current under an electric field. In the present work, Ga and MnO2 were added into 0.7BiFO3–0.3BaTiO3 in order to decrease the leakage current, forming new solid solutions with the general formula of 0.7Bi1+xFe0.98Ga0.02O3–0.3BaTiO3 + ywt%MnO2. Additionally, excess Bi was incorporated into the ceramics to compensate for the volatilization of Bi during high-temperature processes. It was found that both-Bi-excess and MnO2 doping could reduce the leakage current as long as they were maintained at a suitable amount. A combination of strong piezoelectric activity (d33 = 167 pC/N) and a high Curie temperature (TC = 502 °C) was achieved in the ceramics with x = 0.05, y = 0.1. Moreover, the piezoelectric properties of the ceramics exhibited superior thermal stability, reflected in the fact that their d33 decreased by only 25%, from room temperature up to 450 °C.

STRAY currents; THERMAL stability; PIEZOELECTRIC ceramics; ELECTRIC currents; ELECTRIC fields; CURIE temperature

Journal of Materials Science: Materials in Electronics, 2022, Vol 33, Issue 7, p3949

0957-4522

Academic Journal

10.1007/s10854-021-07589-5