1. Ultrahigh thermal stability and piezoelectricity of lead-free KNN-based texture piezoceramics
- Author
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Lihui Xu, Jinfeng Lin, Yuxuan Yang, Zhihao Zhao, Xiaoming Shi, Guanglong Ge, Jin Qian, Cheng Shi, Guohui Li, Simin Wang, Yang Zhang, Peng Li, Bo Shen, Zhengqian Fu, Haijun Wu, Houbing Huang, Fei Li, Xiangdong Ding, Jun Sun, and Jiwei Zhai
- Subjects
Science - Abstract
Abstract The contradiction between high piezoelectricity and uniquely poor temperature stability generated by polymorphic phase boundary is a huge obstacle to high-performance (K, Na)NbO3 -based ceramics entering the application market as Pb-based substitutes. We possess the phase boundary by mimicking Pb(Zr, Ti)O3’s morphotropic phase boundary structure via the synergistic optimization of diffusion phase boundary and crystal orientation in 0.94(Na0.56K0.44)NbO3−0.03Bi0.5Na0.5ZrO3−0.03(Bi0.5K0.5)HfO3 textured ceramics. As a result, a prominent comprehensive performance is obtained, including giant d 33 of 550 ± 30 pC/N and ultrahigh temperature stability (d 33 change rate less than 1.2% within 25-150 °C), representing a significant breakthrough in lead-free piezoceramics, even surpassing the Pb-based piezoelectric ceramics. Within the same temperature range, the d 33 change rate of the commercial Pb(Zr, Ti)O3−5 ceramics is only about 10%, and more importantly, its d 33 (~ 350 pC/N) is much lower than that of the (K, Na)NbO3-based ceramics in this work. This study demonstrates a strategy for constructing the phase boundary with MPB feature, settling the problem of temperature instability in (K, Na)NbO3-based ceramics.
- Published
- 2024
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