Structural, dielectric and piezoelectric characterization of BFN-modified PZT-based (MPB) ceramics

The solid solution of xBi(Fe1/3Nb2/3)O-3-(1-x)Pb(Zr0.50Ti0.50)O-3 ceramics near morphotropic phase boundary (MPB) (BFN-PZT, x = 0, 0.0025, 0.005, 0.0075, 0.01) were prepared by conventional solid-state reaction method. The samples added with different Bi2O3, Fe2O3, Nb2O5 contents were compared in terms of the phase structure, microstructure, dielectric properties, and piezoelectric properties. In particular, rhombohedral-tetragonal morphotropic phase boundary was observed in BFN-PZT crystal structure near the composition of x = 0.005. The BFN-PZT ceramics exhibited the following optimal properties at x = 0.005: dielectric constant epsilon(r) of 847, dielectric loss tan delta of 0.034, Curie temperature T-C of 390 degrees C, electrical conductivity sigma of 0.441 (Mohm.m)(-1), piezoelectric charge constant d(33) of 416 pC/N, electromechanical coupling factor K-P of 0.654, and mechanical quality factor Q(m) of 426, making it a promising material for use in high-intensity ultrasound applications.