Phase transitions and dielectric, ferroelectric and piezoelectric properties of Bi0.5(Na0.82K0.18)0.5TiO3-doped (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 ceramics

This paper reports an investigation of (Ba
0.85
Ca
0.15
)(Zr
0.1
Ti
0.9
)O
3
(50BCZT) piezoelectric ceramics doped with Bi
0.5
(Na
0.82
K
0.18
)
0.5
TiO
3
(18BNKT). For compositions between 1–5 wt% 18BNKT, a perovskite phase was observed in the sintered ceramics, with d
33
values of approximately 370 pC/N measured at room temperature, which is about 80 % of that of pure 50BCZT. Also, the doped materials exhibit a remanent polarization of 2–5 µC/cm
²
at temperatures above the Curie temperature (> 90 °C) of the pure 50BCZT composition. This research shows a promising route to improve the working temperature range whilst maintain good piezoelectric properties of the 50BCZT ceramics.