Zhang Mao-Hua, Shen Chen, Zhao Changhao, Dai Mian, Yao Fang-Zhou, Wu Bo, Ma Jian, Nan Hu, Wang Dawei, Yuan Qibin, da Silva Lucas Lemos, Fulanović Lovro, Schökel Alexander, Liu Peitao, Zhang Hongbin, Li Jing-Feng, Zhang Nan, Wang Ke, Rödel Jürgen, Hinterstein Manuel
State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China.
Department of Materials and Earth Sciences, Technical University of Darmstadt, Darmstadt, Germany.
Nat Commun. 2022 Jun 15;13(1):3434. doi: 10.1038/s41467-022-31158-x.
Here, we introduce phase change mechanisms in lead-free piezoceramics as a strategy to utilize attendant volume change for harvesting large electrostrain. In the newly developed (K,Na)NbO solid-solution at the polymorphic phase boundary we combine atomic mapping of the local polar vector with in situ synchrotron X-ray diffraction and density functional theory to uncover the phase change and interpret its underlying nature. We demonstrate that an electric field-induced phase transition between orthorhombic and tetragonal phases triggers a dramatic volume change and contributes to a huge effective piezoelectric coefficient of 1250 pm V along specific crystallographic directions. The existence of the phase transition is validated by a significant volume change evidenced by the simultaneous recording of macroscopic longitudinal and transverse strain. The principle of using phase transition to promote electrostrain provides broader design flexibility in the development of high-performance piezoelectric materials and opens the door for the discovery of high-performance future functional oxides.
在此，我们介绍无铅压电陶瓷中的相变机制，作为一种利用伴随的体积变化来获取大电致应变的策略。在新开发的处于多晶相界的(K,Na)NbO固溶体中，我们将局部极化矢量的原子映射与原位同步加速器X射线衍射及密度泛函理论相结合，以揭示相变并解释其内在本质。我们证明，正交相和四方相之间的电场诱导相变会引发显著的体积变化，并在特定晶体学方向上产生高达1250 pm V的巨大有效压电系数。通过同时记录宏观纵向和横向应变所证明的显著体积变化，验证了相变的存在。利用相变来促进电致应变的原理为高性能压电材料的开发提供了更广泛的设计灵活性，并为发现未来的高性能功能氧化物打开了大门。
