Abstract: Piezoelectric ceramics, which can realize the conversion between mechanical energy and electrical energy, are widely used in sensors, brakes, ultrasonic transducers, medical ultrasonic imaging and engine fuel injection systems. For piezoelectric ceramics, element doping can effectively control the electrical properties of ceramics. Defect dipoles which are caused by doping have significant and unique influence on the performance of piezoelectric ceramics. Therefore, studying the regulation mechanism of defect dipoles on the properties of piezoelectric ceramics is helpful to understand the origin of many physical phenomena, such as aging and fatigue. The oxygen vacancy introduced by element doping can lead to the formation of defect dipoles in perovskite piezoelectric ceramics, and the coupling effect between the defect dipoles and spontaneous polarization can affect the ferroelectric response behavior of the ceramics, resulting in the pinched polarization hysteresis loop and asymmetric polarization hysteresis loop. In addition, the low diffusion rate of oxygen vacancies in ceramics stabilizes the polarization direction of defect dipoles, which restrains the polarization rotation and restricts the motion of domain walls, thus improving the mechanical quality factor. Numerous studies have adjusted the macroscopic properties of piezoelectric ceramics through defect dipoles to make it meet different application requirements. However, due to piezoelectric ceramics are polycrystalline materials with different grain orientations and complex ferroelectric domain structures. Therefore, the microscopic mechanism during the formation process of the defect dipoles and its specific shape in the piezoelectric ceramics and the specific mechanism of the effect of the defect dipoles on the properties of piezoelectric ceramics need to be further studied. In addition, the high-power characteristics of piezoelectric ceramics under high driving fields are of great help to the actual design of electromechanical devices. Therefore, the impact of defect dipoles on the high-power characteristics of piezoelectric ceramics should also be paid attention to. The research progress in the field of the mechanism of defect dipoles regulating the properties of lead-based piezoelectric ceramics is summarized in this paper. The formation and characterization of defect dipoles caused by oxygen vacancies, the influence of defect dipoles on the hysteresis loops of piezoelectric ceramics, and the influence of doping of different low valence elements on the mechanical quality factor (Qm) of lead-based piezoelectric ceramics are discussed. It can be summarized that the coupling between the defect dipoles and the spontaneous polarization of piezoelectric ceramics leads to pinched polarization hysteresis loops and asymmetric polarization hysteresis loops. In addition, the defect dipoles can improve the mechanical quality factor of materials by suppressing polarization rotation and limiting domain wall motion. However, further research is needed to study the shape and distribution of the defect dipoles, the coupling between the defect dipoles and the non-tetragonal phase, and its effect on the high power characteristics of the piezoelectric ceramics.
1 Haertling G H. Ceramic Society, 2010, 82(4), 797. 2 Kenji U. Advanced piezoelectric materials (second edition), Woodhead Publishing, The United Kingdom, 2017, pp. 95. 3 Zhang S, Xia R, Lebrun L. Materials Letters, 2005, 59(27), 3471. 4 Kenji U. Advanced piezoelectric materials (second edition), Woodhead Publishing, The United Kingdom, 2017, pp. 1. 5 Kenji U. Advanced piezoelectric materials (second edition), Woodhead Publishing, The United Kingdom, 2017, pp. 647. 6 Yu Y, Yang J, Wu J, et al. Ceramics International, 2020, 46(11), 19103. 7 Luo N, Zhang S, Li Q, et al. Journal of Materials Chemistry C, 2016, 4(20), 4568. 8 Zhao Z, Dai Y, Li X, et al. Applied Physics Letters, 2016, 108(17), 172906. 9 Zhao Z H, Dai Y, Huang F. Sustainable Materials and Technologies, 2019, 20, e00092. 10 Cheng M C, Fang Z, Li F, et al. Ceramics International, 2020, 46(9), 13324. 11 Zheng L M, Yang L Y, Li Y R, et al. Physical Review Applied, 2018, 9(6), 064028. 12 Tan Q, Li J X, Viehland D. Applied Physics Letters, 1999, 75(3), 418. 13 Luo X, Zeng J, Shi X, et al. Ceramics International, 2018, 44(7), 8456. 14 Ren X B. Nature Materials, 2004, 3(2), 91. 15 Ren X B, Otsuka K. Physical Review Letters, 2000, 85(5), 1016. 16 Dai Y J, Zhao Y J, Zhao Z, et al. Journal of Physics D Applied Physics, 2016, 49(27), 275303. 17 Lamoreaux R H, Hildenbran D L. Journal of Physical and Chemical Reference Data, 1984, 13(1), 151. 18 Eichel R A. Journal of the American Ceramic Society, 2010, 91(3), 691. 19 Qiao H, He C, Wang Z, et al. Materials and Design, 2017, 117, 232. 20 Tian S, Cao L, Zhang Y, et al. Ceramics International, 2020, 46(8), 10040. 21 Fu J, Zuo R, Qi H, et al. Applied Physics Letters, 2019, 114(9), 092904. 22 Du H, Shi X, Cui Y. Solid State Communications, 2010, 150(27), 1213. 23 Eichel R A, Dinse K P, Kungl H, et al. Applied Physics A, 2005, 80(1), 51. 24 Mestric H, Eichel R, Dinse K, et al. Journal of Applied Physics, 2004, 96(12), 7440. 25 Wu Q, Hao M, Zeng Z, et al. Ceramics International, 2017, 43(14), 10866. 26 Jin L, Li F, Zhang S. Journal of the American Ceramic Society, 2014, 97(1), 1. 27 Tan X, Ma C, Frederick J, et al. Journal of the American Ceramic Society, 2011, 94(12), 4091. 28 Huband S, Thomas P A. Journal of Applied Physics, 2017, 121(18), 184105. 29 Gao Y, Uchino K, Viehland D. Journal of Applied Physics, 2007, 101(5), 054109. 30 Liu W, Zhang L, Chen W, et al. Applied Physics Letters, 2011, 99(9), 092907. 31 Zhang B, Qi H, Zuo R. Ceramics International, 2017, 44(5), 5453. 32 Rojac T, Drnovsek S, Bencan A, et al. Physical Review B, 2016, 93(1), 014102. 33 Garcia J E, Perez R, Ochoa D A, et al. Journal of Applied Physics, 2008, 103(5), 054108. 34 Morozov M I, Damjanovic D. Journal of Applied Physics, 2010, 107(3), 361. 35 Zheng T, Wu J, Xiao D, et al. Progress in Materials Science, 2018, 98, 552. 36 Liu G, Zhang S, Jiang W, et al. Materials Science and Engineering: R: Reports, 2015, 89, 1. 37 Uchino K, Zheng J H, Chen Y H, et al. Journal of Materials Science, 2006, 41(1), 217. 38 Zeng J, Zhao K, Shi X, et al. Scripta Materialia, 2018, 142, 20. 39 Sun Q C, Liu T. Journal of Wuhan University of Technology Materials Science Edition, 2005, 20, 1. 40 He L X, Li C E. Journal of Materials Science, 2000, 35, 2477. 41 Chen Y H, Uchino K, Shen M, et al. Journal of Applied Physics, 2001, 90(3), 14. 42 Qi X, Sun E, Wang J, et al. Ceramics International, 2016, 42(14), 15332. 43 Jakes P, Erdem E, Eichel R A, et al. Applied Physics Letters, 2011, 98(7), 451. 44 Chandrasekaran A, Damjanovic D, Setter N, et al. Physical Review B, 2013, 88(21), 214116. 45 Kim S J, Ha J Y, Choi J W, et al. Japanese Journal of Applied Physics, 2007, 46(2), 691. 46 Lee S, Lee S, Yoon C, et al. Journal of Electroceramics, 2007, 18(3), 311. 47 Yoo J, Lee S. Journal of Electroceramics, 2008, 23(2), 432. 48 Zhang Y, Chen H, Mao D. Ceramics International, 2013, 39, S159. 49 Wang D, Cao M, Zhang S. Physica Status Solidi (RRL)-Rapid Research Letters, 2012, 6(3), 135. 50 Yan Y, Xu Y, Feng Y. Ceramics International, 2014, 40(4), 5897. 51 Huang T, Fu J, Zuo R. Journal of Materials Science: Materials in Electronics, 2019, 30, 9540. 52 Ahn C W, Song H C, Nahm S, et al. Journal of the American Ceramic Society, 2006, 89(3), 921. 53 Chao X, Ma D, Gu R, et al. Journal of Alloys and Compounds, 2010, 491(1), 698. 54 Yoo J. Ferroelectrics, 2011, 423(1), 135. 55 Zhu K J, Qiu J H, Su L K, et al. Sciencepaper Online, 2010, 5(4), 278 (in Chinese). 朱孔军,裘进浩,苏礼奎, 等.中国科技论文在线, 2010, 5(4), 278. 56 Gao Y, Chen Y H, Ryu J, et al. Japanese Journal of Applied Physics, 2001, 40(2A), 687. 57 Gao Y K, Uchino K, Viehland D. Journal of Applied Physics, 2002, 92(4), 20. 58 Feng Y, Wu J, Chi Q, et al. Chemical Reviews, 2020, 120(3), 1710.