Dielectric, Ferroelectric, and Piezoelectric Properties of Bi ( Ni _1/2 Ti _1/2 ) O ₃ ‐Modified BiFeO ₃ – BaTiO ₃ Ceramics with High Curie Temperature

Abstract

New piezoelectric ceramics, 0.71 BiFe 1− x ( Ni 1/2 Ti 1/2 ) x O 3 −0.29 BaTiO 3 +0.6 wt% MnO 2 [ BFNT x – 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/cm 2 , 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.