Role of Bi₂O₃ and PbO excess on the Di-/ferro-/piezoelectric and bi-polar strain properties in 0.39Bi(Ni_0.5Ti_0.5)O₃–0.20PbZrO₃–0.41PbTiO₃ ternary ceramics near MPB

0.39Bi(Ni_0.5Ti_0.5)O₃–0.20PbZrO₃–0.41PbTiO₃:x(Bi₂O₃ + PbO) (BNPZT:xBiPb, x = 0, 1, and 2) piezoceramics were prepared via conventional solid-state route. The impact of excess Bi₂O₃ and PbO on the structural, dielectric, ferroelectric, bipolar strain, and piezoelectric properties of BNPZT ceramics was investigated. The Rietveld refinement results indicated that all sintered ceramics were well crystallized into a pure perovskite structure with major rhombohedral and minor tetragonal phases. The temperature and frequency dependence of dielectric measurements revealed relaxor behavior and a high Curie temperature (Tc ~ 290 °C) for BNPZT:1BiPb ceramics. High remnant polarization (Pr ~ 25.43 μC/cm²), low coercive field (Ec ~ 16.73 kV/cm), and bipolar strain (0.12%) were achieved in BNPZT:1BiPb ceramics. This study outlines a route for exploring new piezoelectric materials with enhanced electrical properties.