Defect dipole stretching enables ultrahigh electrostrain.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38985865.
- Also identified by DOI 10.1126/sciadv.adn2829 and PMC identifier 11235158.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Piezoelectric actuators have been extensively utilized as micro-displacement devices because of their advantages of large output displacement, high sensitivity, and immunity to electromagnetic interference. Here, we propose a straightforward approach to design <110>-oriented defect dipoles by introducing A-site vacancies and oxygen vacancies in (K<sub>0.48</sub>Na<sub>0.52</sub>)<sub>0.99</sub>NbO<sub>2.995</sub> ceramics. As a result, we achieve ultrahigh electrostrains of 0.7% at 20 kV cm<sup>-1</sup> (with an effective piezoelectric strain coefficient <i>d</i><sub>33</sub><sup>*</sup> = 3500 pm V<sup>-1</sup>), outperforming the performance of existing piezoelectric ceramics at the same driving field. The exceptional electrostrain is primarily attributed to the large stretching of defect dipoles when subjected to an applied electric field, a phenomenon that has been experimentally confirmed. Moreover, the strong interaction between these defect dipoles and <110> spontaneous polarizations plays a critical role in minimizing hysteresis and ensuring excellent fatigue resistance. Our findings present a practical and effective strategy for developing high-performance piezoelectric materials tailored for advanced actuator applications.