One simple approach, two remarkable enhancements: Manipulating defect dipoles and local stress of (K, Na)NbO3-based ceramics

Xi xi Sun, Ruichen Li, Chunlin Zhao, Xiang Lv, Jiagang Wu

Research output: Contribution to journalArticlepeer-review

15 Scopus citations

Abstract

Although the composition-driven multi-phase coexistence strategy has been widely used to modify the piezoelectric properties of potassium sodium niobate ((K, Na)NbO3, KNN) based ceramics, the trade-off between long-range ferroelectric ordering and chemical additives-induced disorder hinders the further improvement of piezoelectricity and makes the electric field-induced strain temperature-dependent. Herein, to resolve two issues, we proposed a new concept, that is, manipulating defect dipoles and local stress of a pre-constructed multi-phase coexistence through controlling zirconium (Zr) content. We validated the new concept by designing 0.96(K0.4Na0.6)Nb0.955Sb0.045O3-0.04(Bi0.5Na0.5)Zr(1+x)O3 ceramics. In samples with Zr deficiency (i.e., x=-0.1), we obtained high retention of 91% in normalized unipolar strain (Suni) over the temperature range of 30-160 °C, even under low electric fields of 10-20 kV/cm, superior to those of other representative KNN-based ceramics. In samples with slight Zr excess (i.e., x=0.07), we achieved an increase in direct piezoelectric coefficient (d33) and converse piezoelectric coefficient (d33*) by 12% and 25%, respectively, in comparison with that at x=0. The enhanced temperature stability stems from the released domain walls that are pinned by defect dipoles, and the increased d33 (and d33*) originates from the synergetic contributions of the multi-phase coexistence, increased grain size, and stabilization of the ZrO2 secondary phase. Therefore, our new concept would benefit the composition design and performance improvement of KNN-based ceramics in the future.
Original languageEnglish (US)
Pages (from-to)117351
JournalActa Materialia
Volume221
DOIs
StatePublished - Sep 27 2021
Externally publishedYes

Bibliographical note

KAUST Repository Item: Exported on 2021-10-28
Acknowledgements: This work is supported by the R&D Projects in Key Fields of Guangdong Province, China (Grant No. 2020B0109380001) and the National Natural Science Foundation of China (NSFC Nos. 51722208 and 52061130216). We appreciate the support from Prof. Xi-xiang Zhang (King Abdullah University of Science and Technology) for measuring the temperature-dependent dielectric properties and the support from Ms. Hui Wang (Analytical & Testing Center of Sichuan University) for conducting the FE-SEM measurements.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.

ASJC Scopus subject areas

  • Polymers and Plastics
  • Metals and Alloys
  • Ceramics and Composites
  • Electronic, Optical and Magnetic Materials

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