Zhou Xuefan, Zhang Jun, Luo Hang, Zhang Yan, Tang Shiyu, Huang Houbing, Yuan Xi, Song Miao, Qi He, Zhang Dou
State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan, 410083, China.
School of Materials Science and Engineering and Advanced Research Institute of Multidisciplinary Science, Beijing Institute of Technology, Beijing, 100081, China.
Nat Commun. 2024 Aug 5;15(1):6625. doi: 10.1038/s41467-024-51082-6.
The trade-off between electrostrain and strain hysteresis for piezo/ferroelectric materials largely restrains the development of high precision actuators and remains unresolved over the past few decades. Here, a simple composition of (BiNa)SrTiO in the ergodic relaxor state is collaboratively designed through the segregated domain structure with the ferroelectric core, local polarization heterogeneity, and defect engineering. The ferroelectric core can act as a seed to facilitate the field-induced nonpolar-to-polar transition. Together with the internal bias field caused by defect dipoles and adjusted through electric field cycling and heat treatment technology, a giant unipolar strain of 1.03% is achieved in the x = 30 ceramic with a low hysteresis of 27%, while the electric-field-independent large-signal piezoelectric strain coefficient of ~1000 pm/V and ultralow hysteresis of <10% can be obtained in the x = 35 ceramic. Intriguingly, the low-hysteresis high strain also exhibits near-zero remnant strain, excellent temperature and cycling stability.
压电/铁电材料中电应变与应变滞后之间的权衡在很大程度上限制了高精度致动器的发展，并且在过去几十年中一直未得到解决。在此，通过具有铁电核心、局域极化不均匀性和缺陷工程的分离畴结构，协同设计了处于遍历弛豫态的简单成分（BiNa）SrTiO。铁电核心可作为种子促进场致非极性到极性的转变。与由缺陷偶极引起并通过电场循环和热处理技术调节的内偏置场一起，在x = 30的陶瓷中实现了1.03%的巨大单极应变，滞后低至27%，而在x = 35的陶瓷中可获得约1000 pm/V的与电场无关的大信号压电应变系数和<10%的超低滞后。有趣的是，低滞后高应变还表现出近零残余应变、优异的温度和循环稳定性。
