Effect of B₂O₃ doping on structure and properties of 0.76BF-0.24BT high temperature lead-free piezoelectric ceramics

In order to study the effect of doping B₂O₃ on ceramics, 0.76BiFeO₃-0.24BaTiO₃-xB₂O₃(0.76BF-0.24BT-xBO) high temperature lead-free piezoelectric ceramics were prepared by solid phase synthesis method, x is the mole fraction. The effects of different BO content on phase structure, microstructure, electrical properties, Curie temperature and depolarization temperature of ceramics were studied. XRD analysis show that all samples are of rhomb tripartite perovskite structure. The observation of microstructure shows that the grain distribution is uniform, and there is liquid phase between grain boundaries, and the grain size increases with the increase of x. The optimal sintering temperature of ceramics was reduced from 960 ℃ to 940 ℃. When x = 0.1, the excellent electrical properties are obtained: d₃₃ = 101 pC·N⁻¹, P_r = 21.5 μC·cm⁻². 0.76BF-0.24BT-xBO ceramics have good high temperature stability: T_C = 585 ℃, T_d = 560 ℃. The results show that the doping of B₂O₃ can improve the microstructure, reduce the sintering temperature and improve the electrical properties of 0.76BF-0.24BT ceramics.