Investigation of a new lead-free (0.89−x)(Bi0.5Na0.5)TiO3–0.11(Bi0.5K0.5)TiO3–xBa0.85Ca0.15Ti0.90Zr0.10O3 ceramics

Abstract (0.89 − x)(Bi0.5Na0.5)TiO3–0.11(Bi0.5K0.5)TiO3–xBa0.85Ca0.15Ti0.90Zr0.10O3 (BNT–BKT–BCTZx) ceramics were prepared by the conventional solid-state method. The dependence of BCTZ content on the microstructure and electrical properties of BNT–BKT–BCTZx ceramics is investigated. The BCTZ diffuses into the BNT–BKT lattice to form a stable solid solution, and a coexistence of rhombohedral and tetragonal phase is observed in these ceramics with the composition of 0.04 ≤ x ≤ 0.08. An enhanced piezoelectric behavior of d33 ∼ 198 pC/N and kp ∼ 25.4% is demonstrated in the ceramic with x = 0.06. Moreover, the introduction of BCTZ also improves the remanent polarization and decreases the coercive field, and the improvement in ferroelectric properties of 2Pr ∼ 48.77 μC/cm2 and 2Ec ∼ 52.92 kV/cm is observed in such a ceramic with x = 0.06. As a result, the BNT–BKT–BCTZx ceramic is a promising candidate for lead-free piezoelectric materials.