Abstract
(Bi0.5Na0.5)TiO3-BaTiO3 (BNT-BT) lead-free piezoelectric ceramics with compositions near the rhombohedral-tetragonal morphotropic phase boundary (MPB) have been prepared and investigated. In this work, the best properties was observed in BNT-0.07BT, with the piezoelectric coefficient d33 and the planar electromechanical coupling factor kp being 151 pC/N and 0.278, respectively. The dielectric response of the poled (Bi0.5Na0.5)TiO3-xBaTiO3 ceramics were investigated as a function of composition and temperature using Rayleigh analysis, dielectric Rayleigh coefficient α and initial dielectric constant εinit increase with x increasing, and has a substantial increase in the tetragonal phase. Detailed analysis of the temperature dependence of α and εinit curves of all compositions revealed different temperature in the maximum value due to the dominate contributions of domain wall motion.