Effects of Nb doping on the microstructure, ferroelectric and piezoelectric properties of 0.7BiFeO(3)-0.3BaTiO(3) lead-free ceramics

摘要

Donor-doped lead-free Bi0.7Ba0.3(Fe0.7Ti0.3)(1-x) Nb-0.66x O-3 + 1 mol% MnO2 ceramics were prepared by a conventional oxide-mixed method and the effects of Nb-doping on microstructure, piezoelectric and ferroelectric properties of the ceramics were investigated. All the ceramics exhibit a pure perovskite structure with rhombohedral symmetry. The grain growth of the ceramics is inhibited after the addition of Nb doping. High electric insulation (R = 10(9)-10(10) Omega a <...cm) and the poor piezoelectric performance and weak ferroelectricity are observed after the addition of Nb2O5 in the ceramics. Different from the donor effect of Pb-based perovskite ceramics, the introduction of Nb into 0.7BiFeO(3)-0.3BaTiO(3) degrades the piezoelectricity and ferroelectricity of the ceramics. The Bi0.7Ba0.3(Fe0.7Ti0.3)(1-x) Nb-0.66x O-3 + 1 mol% MnO2 ceramic with x = 0 exhibits the optimum piezoelectric properties with d (33) = 133 pN C-1 and k (p) = 0.29 and high Curie temperature (T-C = 603(a similar to)C).