Affiliation:
1. College of Materials Science and Engineering Sichuan University Chengdu 610065 P. R. China
2. State Key Laboratory for Mechanical Behavior of Materials Xi'an Jiaotong University Xi'an 710049 P. R. China
3. Electronic Materials Research Laboratory (Key Lab of Education Ministry) and School of Electronic and Information Engineering Xi'an Jiaotong University Xi'an 710049 China
4. School of Physical and Information Sciences Shaanxi University of Science & Technology Xi'an 710021 China
5. Division of Physical Science and Engineering King Abdullah University of Science and Technology Thuwal 23955–6900 Saudi Arabia
Abstract
AbstractPiezoceramics with large strain output, low hysteresis, and wide operation temperature are indispensable for the high‐end displacement control. Unfortunately, requiring these merits simultaneously remains a long‐standing challenge for lead‐free piezoceramics promising for replacing lead‐based ones. Herein a new strategy to resolve this challenge by developing modified re‐entrant‐like potassium sodium niobate ((K, Na)NbO3, KNN) relaxors is presented. Multi‐scale structural analysis reveals the presence of the significant local disorder, nano‐sized multi‐phase coexistence, and ultra‐fine grains, which facilitate the polarization rotation, effectively eliminate non‐180° domains, and erase polymorphic phase transition features in re‐entrant‐like KNN relaxors. Consequently, a combination of large strain (≈0.19%), ultra‐low hysteresis (<7%), high electrostriction coefficient (Q33 = 0.049 m4 C−2), and benign temperature stability (i.e., strain varies less than 10.6% within 30–120 °C) is realized, superior to other lead‐free relaxors. Therefore, this strategy provides a novel paradigm for designing high‐performance lead‐free piezoceramics used for high‐precision actuators.
Funder
National Natural Science Foundation of China
National Key Research and Development Program of China
Natural Science Foundation of Sichuan Province
Fundamental Research Funds for the Central Universities