Ca²⁺ doping effects in (K, Na, Li)(Nb_0.8Ta_0.2)O₃ lead-free piezoelectric ceramics

Abstract

Lead-free (K_0.5−x/2Na_0.5−x/2Li_x)(Nb_0.8Ta_0.2)O₃ (KNLNT) and (K_0.49−x/2Na_0.49−x/2- Li_xCa_0.01)(Nb_0.8Ta_0.2)O₃ (KNLNT-Ca) ceramics were prepared by a conventional ceramic processing. Structural analysis shows that the Ca²⁺ doping takes the A site of ABO₃ perovskite and decreases the phase transition temperature. Property measurements reveal that as a donor dopant, the Ca²⁺ doping results in higher room-temperature dielectric constant, lower dielectric loss, and lower mechanical quality factor. In addition, the Ca²⁺ doping does not change the positive piezoelectric coefficient d₃₃, but increases the converse piezoelectric coefficient d₃₃^* significantly. This is likely due to the increase in the relaxation, as well as the appearance of (Ca_Na/K^•--V_Na/K′) defect dipoles.

Key words： lead-free piezoelectric; KNN; converse piezoelectric coefficient; donor dopant; piezoelectric property; polymorphic phase transition

Acknowledgement

This work was supported by the National Natural Science Foundation of China (Grant No. 21371056).

References

1 Jaffe B, Cook W R, Jaffe H. Piezoelectric Ceramics. New York: Academic Press, 1971

2 Uchino K. Ferroelectric Devices. New York: CRC Press, 2009

3 Tichy J, Erhart J, Kittinger E, . Fundamentals of Piezoelectric Sensorics: Mechanical, Dielectric, and Thermodynamical Properties of Piezoelectric Materials. Berlin: Springer Press, 2010

4 Mishra M K, Moharana S, Behera B, . Surface functionalization of BiFeO₃: a pathway for the enhancement of dielectric and electrical properties of poly(methyl methacrylate)–BiFeO₃ composite films. Frontiers of Materials Science, 2017, 11(1): 82–91

5 Saito Y, Takao H, Tani T, . Lead-free piezoceramics. Nature, 2004, 432(7013): 84–87

PMID

6 Shrout T R, Zhang S J. Lead-free piezoelectric ceramics: alternatives for PZT? Journal of Electroceramics, 2007, 19(1): 113–126

7 Rodel J, Jo W, Seifert K T P, . Perspective on the development of lead-free piezoceramics. Journal of the American Ceramic Society, 2009, 92(6): 1153–1177

8 Li J F, Wang K, Zhu F Y, . (K, Na)NbO₃-based lead-free piezoceramics: fundamental aspects, processing technologies, and remaining challenges. Journal of the American Ceramic Society, 2013, 96(12): 3677–3696

9 Rodel J, Webber K G, Dittmer R, . Transferring lead-free piezoelectric ceramics into application. Journal of the European Ceramic Society, 2015, 35(6): 1659–1681

10 Tan Z, Xing J, Jiang L, . Ga₂O₃ doping and vacancy effect in KNN–LT lead-free piezoceramics. Frontiers of Materials Science, 2017, 11(4): 344–352

11 Chen K, Jiao Y. Effects of Ge⁴⁺ acceptor dopant on sintering and electrical properties of (K_0.5Na_0.5)NbO₃ lead-free piezoceramics. Frontiers of Materials Science, 2017, 11(1): 59–65

12 Wu J, Xiao D, Zhu J. Potassium-sodium niobate lead-free piezoelectric materials: past, present, and future of phase boundaries. Chemical Reviews, 2015, 115(7): 2559–2595

13 Zhang S J, Lee H J, Ma C, . Sintering effect on microstructure and properties of (K, Na)NbO₃ ceramics. Journal of the American Ceramic Society, 2011, 94(11): 3659–3665

14 Guo Y P, Kakimoto K, Ohsato H. Phase transitional behavior and piezoelectric properties of (Na_0.5K_0.5)NbO₃–LiNbO₃ ceramics. Applied Physics Letters, 2004, 85(18): 4121–4123

15 Guo Y P, Kakimoto K i, Ohsato H. (Na_0.5K_0.5)NbO₃–LiTaO₃ lead-free piezoelectric ceramics. Materials Letters, 2005, 59(2–3): 241–244

16 Dai Y, Zhang X, Zhou G. Phase transitional behavior in (Na_0.5K_0.5)NbO₃–LiTaO₃ ceramics. Applied Physics Letters, 2007, 90(26): 262903

17 Zhang S, Xia R, Shrout T R. Modified (K_0.5Na_0.5)NbO₃ based lead-free piezoelectrics with broad temperature usage range. Applied Physics Letters, 2007, 91(13): 132913

18 Wu J G, Xiao D Q, Wang Y Y, . Improved temperature stability of CaTiO₃-modified [(K_0.5Na_0.5)_0.96Li_0.04](Nb_0.91Sb_0.05Ta_0.04)O₃ lead-free piezoelectric ceramics. Journal of Applied Physics, 2008, 104(2): 024102

19 Chang Y F, Poterala S, Yang Z P, . Enhanced electromechanical properties and temperature stability of textured (K_0.5Na_0.5)NbO₃-based piezoelectric ceramics. Journal of the American Ceramic Society, 2011, 94(8): 2494–2498

20 Zhang M H, Wang K, Zhou J S, . Thermally stable piezoelectric properties of (K, Na)NbO₃-based lead-free perovskite with rhombohedral-tetragonal coexisting phase. Acta Materialia, 2017, 122: 344–351

21 Damjanovic D. Hysteresis in piezoelectric and ferroelectric materials. In: Bertotti G, Mayergoyz I D, eds. The Science of Hysteresis. Elsevier, 2005, 337–465

22 Zheng T, Wu J, Xiao D, . Giant d₃₃ in nonstoichiometric (K, Na)NbO₃-based lead-free ceramics. Scripta Materialia, 2015, 94: 25–27

23 Jiang L, Li Y, Xing J, . Phase structure and enhanced piezoelectric properties in (1−x)(K_0.48Na_0.52)(Nb_0.95Sb_0.05)O₃–x(Bi_0.5Na_0.42Li_0.08)_0.9Sr_0.1ZrO₃ lead-free piezoelectric ceramics. Ceramics International, 2017, 43(2): 2100–2106

24 Lee K T, Lee T G, Kim S W, . Thermally stable high strain and piezoelectric characteristics of (Li, Na, K)(Nb, Sb)O₃-CaZrO₃ ceramics for piezo actuators. Journal of the American Ceramic Society, 2019, 102(10): 6115–6125

25 Hao J, Li W, Zhai J, . Progress in high-strain perovskite piezoelectric ceramics. Materials Science and Engineering R: Reports, 2019, 135: 1–57

26 Zhang Y, Li J F. Review of chemical modification on potassium sodium niobate lead-free piezoelectrics. Journal of Materials Chemistry C: Materials for Optical and Electronic Devices, 2019, 7(15): 4284–4303

27 Chen K, Zhang F, Li D, . Acceptor doping effects in (K_0.5Na_0.5)NbO₃ lead-free piezoelectric ceramics. Ceramics International, 2016, 42(2): 2899–2903

28 Zhao Y, Chen Y, Chen K. Improvement in synthesis of (K_0.5Na_0.5)NbO₃ powders by Ge⁴⁺ acceptor doping. Frontiers of Materials Science, 2016, 10(4): 422–427

29 Chen K, Zhang F, Li D, . Acceptor doping effects in (K_0.5Na_0.5)NbO₃ lead-free piezoelectric ceramics. Ceramics International, 2016, 42(2): 2899–2903

30 Chen K, Tang J. Effects of acceptor doping on sintering and piezoelectric properties of (K_0.4825Na_0.4825Li_0.035)(Nb_0.8Ta_0.2)O₃ lead-free piezoelectric ceramics. Journal of Alloys and Compounds, 2017, 695: 3364–3369

31 Chen K, Zhang F, Jiao Y, . Effects of GeO₂ addition on sintering and properties of (K_0.5Na_0.5)NbO₃ ceramics. Journal of the American Ceramic Society, 2016, 99(5): 1681–1686

32 Chen K, Zhou J, Zhang F, . Screening sintering aids for (K_0.5Na_0.5)NbO₃ ceramics. Journal of the American Ceramic Society, 2015, 98(6): 1698–1701

33 Wang T, Wang D, Liao Y, . Defect structure, ferroelectricity and piezoelectricity in Fe/Mn/Cu-doped K_0.5Na_0.5NbO₃ lead-free piezoelectric ceramics. Journal of the European Ceramic Society, 2018, 38(15): 4915–4921

34 Coondoo I, Panwar N, Maiwa H, . Improved piezoelectric and energy harvesting characteristics in lead-free Fe₂O₃ modified KNN ceramics. Journal of Electroceramics, 2015, 34(4): 255–261

35 Zhao Z H, Dai Y J, Huang F. The formation and effect of defect dipoles in lead-free piezoelectric ceramics: A review. Sustainable Materials and Technologies, 2019, e00092

36 Uchino K, Nomura S. Critical exponents of the dielectric constants in diffused-phase-transition crystals. Ferroelectrics, 1982, 44(1): 55–61

37 Damjanovic D. Ferroelectric, dielectric and piezoelectric properties of ferroelectric thin films and ceramics. Reports on Progress in Physics, 1998, 61(9): 1267–1324

38 Dai Y J, Zhao Y J, Zhao Z, . High electrostrictive strain induced by defect dipoles in acceptor-doped (K_0.5Na_0.5)NbO₃ ceramics. Journal of Physics D: Applied Physics, 2016, 49(27): 275303