Enhanced electrical properties of (Bi0.5Na0.5)TiO3-modified BiFeO3-BaTiO3 lead-free ceramics

There is a significant challenge for current BiFeO3-BaTiO3 based piezoelectric ceramics to achieve an enhancement in piezoelectric performance without sacrificing phase transition temperature. Here, a new leadfree ceramics material system of (1-x) (0.7BiFeO3-0.3BaTiO3)-x(Bi0.5Na0.5) TiO3-5 mol%Bi2O3 (BF-BT-xBNT) is reported, achieving significant improvement in piezoelectric properties at stable phase transition temperature with piezoelectric constant d33 = 202 pC/N and phase transition temperature Tm = 484 degrees C, respectively. The synergy effect of reduced the ratio of rhombohedral (R) and tetragonal (T) phases, the coexistence of microdomains and macro-domains, appropriate grain size, enhanced relative density and diminished leakage current contributs to favorable ferroelectric and piezoelectric properties. The investigation of BNT-doping on the BFBT-based piezoceramics will provide some useful references for the development of high-performance BF-BT piezoelectric materials.