Enhanced insulation and ferro/piezo-electric properties of BiFeO₃-BaTiO₃ via synchronous B-site co-doping and quenching treatment

Lead-free piezoelectric ceramics 0.7BiFe(1-x)(Zn0.5Sn0.5)(x)O-3-0.3BaTiO(3) [BF(ZS)(x)-BT] were successfully prepared using the solid-state reaction method. The dual effects of B-site Zn/Sn co-doping and quenching on the structure and piezoelectricity of BF(ZS)(x)-BT were investigated. All samples showed a distinct perovskite structure, characterized by the simultaneous presence of rhombohedral (R) and pseudo-cubic (pC) phases. The insulation and electrical properties were significantly increased by appropriate Zn/Sn co-doping and quenching treatment. The long parallel strip domains and enhanced lattice distortion synergistically contribute to the outstanding piezoelectricity (d(33) = 203 pC/N) and a high Curie temperature (T-c = 493 degrees C) in quenched BF(ZS)(0.003)-BT. Furthermore, the quenching treatment was found to further improve the piezoelectric property and enhance its high-temperature stability, as demonstrated by the in-situ electromechanical coupling coefficient (k(p)) and thermal depolarization test. The d(33) of the quenched BF(ZS)(0.003)-BT was maintained at 186 pC/N around 400 degrees C, highlighting its promising applications in medium-high temperature conditions.