Effect of Ba0.85Ca0.15Ti0.90Zr0.10O3 content on the microstructure and electrical properties of Bi0.51(Na0.82K0.18) 0.50TiO3 ceramics

(1−x)Bi0.51(Na0.82K0.18)0.50TiO3–xBa0.85Ca0.15Ti0.90Zr0.10O3 [(1−x)BNKT–xBCTZ] ceramics were prepared by the conventional solid-state method, and the effect of BCTZ content on their microstructure and electrical properties was investigated. A stable solid solution with a pure perovskite phase is formed between BNKT and BCTZ, and these ceramics have a coexistence of rhombohedral and tetragonal phases in the range of 0 ≤ x < 0.15. Their Tm and Td values are strongly independent on the BCTZ content. Moreover, the sintering temperature strongly affects the ferroelectric and piezoelectric properties of these ceramics with x = 0.02. These ceramics with x = 0.02 exhibit an optimum electrical behavior of d33 ∼ 205, kp ∼ 0.25, Pr ∼ 31.8 μC/cm2, and Ec ∼ 19.1 kV/cm together with a high Td value of ∼91 °C when sintered at 1180 °C and poled at an optimum condition. As a result, the (1−x)BNKT–xBCTZ ceramic is a promising candidate material for lead-free piezoelectric ceramics.