Strong piezoelectricity of Li2CO3-doped BiFeO3–BaTiO3–Bi(Zn0.5Ti0.5)O3 lead-free piezoelectric ceramics with high Curie temperature and high temperature stability

Abstract BiFeO3–BaTiO3–Bi(Zn0.5Ti0.5)O3+xLi2CO3 (BFBT-BZT-xLC) lead-free piezoelectric ceramics with high Curie temperature and high temperature stability were made by refined solid-state reaction approach. More specifically, the phase transformation, microstructure, electric properties and high temperature stability of the ceramics were well studied. Experimental results demonstrate that piezoelectric properties and temperature stability of BFBT-BZT-xLC piezoelectric ceramics were significantly improved by adding Li2CO3 sintering additives. What’s more, when x = 0.3 mol% the ceramics sintered at 970 °C, the results show the optimal electrical properties with kp = 0.357, Qm = 35.687, tanδ = 0.043, d33 = 184 pC/N. In particular, high Curie temperature (TC = 554 °C) and high depolarization temperature (Td = 530 °C, d33 = 150 pC/N) were obtained. Therefore, the results show that BFBT-BZT-xLC ceramics are a promising high temperature lead-free piezoelectric ceramic material.