Simultaneous enhancement of piezoelectric performance and Curie temperature in high-temperature Bi <sub>4</sub>Ti <sub>3</sub>O <sub>12</sub> piezoceramics through A/B site co-doping
Xuanyu Chen, Bao Ou, Guanfu Liu, Yuxing Dai, Bin Li, Yejing Dai
Abstract
For Bi<sub>4</sub>Ti<sub>3</sub>O<sub>12<strong> </strong></sub>(BIT) high-temperature piezoceramics, improving piezoelectric performance often comes at the expense of a reduced Curie temperature. In this study, a series of Bi<sub>4-<em>x</em></sub>Ce<em><sub>x</sub></em>Ti<sub>2.97</sub>(Cr<sub>1/3</sub>Ta<sub>2/3</sub>)<sub>0.03</sub>O<sub>12</sub> (<em>x</em> = 0, 0.02, 0.04, 0.06, and 0.08) ceramics are synthesized using the solid-state reaction method, and their phase structure, microstructure, piezoelectric properties, and conduction mechanisms are systematically analyzed. By employing a B-site non-equivalent co-doping strategy and introducing Ce ions into the A-site, we achieve a synergistic enhancement of piezoelectric performance, Curie temperature, and high-temperature resistivity in BIT-based ceramics. This A/B site multi-co-doping significantly enhances electrical properties by reducing oxygen vacancy concentration. Notably, the ceramic with <em>x</em> = 0.04 exhibits a high piezoelectric coefficient (<em>d</em><sub>33</sub>) of 37 pC N<sup>-1</sup>, excellent resistivity of 6.6 × 10<sup>6</sup> Ω·cm at 500 °C, and a high Curie temperature of 681 °C. Piezoelectric force microscopy and phase field simulation reveal that the superior piezoelectric performance arises from larger domain sizes, a stronger response to external electric fields, and a higher breakdown field strength. These findings not only position this material as a robust candidate for high-temperature applications but also provide valuable insights into the design of piezoelectric ceramics with enhanced stability and performance.