Deciphering the phase transition-induced ultrahigh piezoresponse in (K,Na)NbO3-based piezoceramics

• Published in: Nature communications Vol. 13; no. 1; pp. 3434 - 10
• Main Authors: 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
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 15.06.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 119/118; 147/137; 147/143; 147/28; 639/301/1005/1006; 639/301/119/1002; 639/301/119/996; 639/638/263/915; 639/638/298/917; Crystallography; Density functional theory; Electric fields; External stimuli; Humanities and Social Sciences; Lead free; multidisciplinary; Niobates; Phase change; Phase transitions; Piezoelectric ceramics; Piezoelectricity; Science; Science (multidisciplinary); Solid solutions; Synchrotron radiation; Synchrotrons; X-ray diffraction
• ISSN: 2041-1723; 2041-1723
• 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 3 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 −1 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. Functional oxides with coexisting states of comparable energy typically exhibit extraordinary responses to external stimuli. Here, the authors demonstrate that coexisting phase structures provide large electric field-triggered volume change.