High curie temperature BiFeO3-PbTiO3-Bi(Zn1/2Ti1/2)O3-PbZrO3 piezoceramics with good thermal stability

MPB compositions of (0.80 - x)BiFeO3-(x)PbTiO3-0.15Bi(Zn1/2Ti1/2)O-3-0.05PbZrO(3) (BF-PT-BZT-PZ) ceramics were designed (x = 0.26, 0.28, 0.30) and prepared by the conventional solid state reaction method. The microstructure, ferroelectric, dielectric, piezoelectric properties and thermal degradation were investigated. Typical saturated P-E hysteresis loops were obtained, presenting remnant polarization P-r of 30 mu C/cm(2) and large coercive field E-c of 70 kV/cm. The dielectric and piezoelectric properties increased with PT contents, and the x = 0.30 samples had dielectric constant epsilon(T)(33)/epsilon(0) = 365, loss of tan delta = 0.017, piezoelectric coefficient of d(33) = 85 pC/N, and Curie temperature of T-c similar to 550 degrees C. Thermal annealing investigation showed that all of the three compositions had high temperature stability, and the thermal depolarization temperature of T-d was similar to 450 degrees C.