Dielectric, Ferroelectric, and Piezoelectric Properties of Bi(Ni1/2Ti1/2)O3‐Modified BiFeO3–BaTiO3
Ceramics with High Curie Temperature
New piezoelectric ceramics, 0.71BiFe1−x
O3−0.29BaTiO3+0.6 wt% MnO2
[BFNTx–BT] (x = 0–0.09), were fabricated using conventional mixed‐oxide method. It was found that the introduction of BNT into BF‐BT system caused insignificant change in crystal structure, which is a single‐phase perovskite structure.
However, an obvious variation in microstructure took place. The ceramics with composition of x = 0.03 showed enhanced piezoelectric, electromechanical, and ferroelectric properties with piezoelectric constant d
33 = 156 pC/N, planar electromechanical
coupling factors k
p = 0.308, remnant polarization P
r = 22.5 μC/cm2, and coercive field E
c = 28.2 kV/cm, with a high Curie temperature T
c = 431°C, respectively.
The combination of good piezoelectric properties and high T
c makes these ceramics suitable for elevated temperature piezoelectric devices.