AI Chat Paper
Note: Please note that the following content is generated by AMiner AI. SciOpen does not take any responsibility related to this content.
{{lang === 'zh_CN' ? '文章概述' : 'Summary'}}
{{lang === 'en_US' ? '中' : 'Eng'}}
Chat more with AI
View PDF
Submit Manuscript AI Chat Paper
Show Outline
Show full outline
Hide outline
Show full outline
Hide outline
Research Article | Open Access

Simultaneously improving piezoelectric properties and temperature stability of Na0.5K0.5NbO3 (KNN)-based ceramics sintered in reducing atmosphere

Zhenyong CENaShuaishuai BIANaZe XUaKe WANGaLimin GUObLongtu LIaXiaohui WANGa( )
State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, China
Show Author Information


It is a very difficult work to sinter K0.5Na0.5NbO3 (KNN)-based materials with good reduction resistance in strong reducing atmosphere. 0.945K0.48Na0.52Nb0.96Ta0.04O3-0.055BaZrO3 + 0.03ZrO2 + y mol%MnO (KNNT-0.055BZ + 0.03Zr + yMn) ceramics sintered in reducing atmosphere were prepared successfully by conventional solid-state reaction methods. MnO dopant increases grain size at y = 5-8 due to strong lattice distortion and then decreases grain size at y = 9 due to much Mn4Nb2O9 accumulated at the grain boundary. MnO dopant as an excellent sintering aid can effectively reduce volatilization of alkali metal by decreasing the sintering temperature (Tsinter). Reducing alkali metal volatilization can greatly reduce oxygen vacancies and improve piezoelectric properties. MnO dopant can improve the anti-reduction properties. The KNNT-0.055BZ + 0.03Zr + yMn ceramics at y = 6-9 show outstanding anti-fatigue of unipolar piezoelectric strain under the synergistic effect of reduced oxygen vacancies due to reduced volatilization and increased grain size. Piezoelectric properties and temperature stability of KNNT-0.055BZ + 0.03Zr ceramics sintered in reducing atmosphere are improved simultaneously by MnO dopant. Optimum inverse piezoelectric coefficient (d*33) of ceramics at y = 8 reaches up to 480 pm/V under low driving electric field E = 20 kV/cm at room temperature, and its temperature stability of d*33 reaches 158 ℃. It will be an excellent lead-free material candidate for the preparation of multilayer piezoelectric actuators co-fired with nickel electrode.

Electronic Supplementary Material

Download File(s)
40145_2021_475_MOESM1_ESM.pdf (280.9 KB)


Tao H, Wu H, Liu Y, et al. Ultrahigh performance in lead-free piezoceramics utilizing a relaxor slush polar state with multiphase coexistence. J Am Chem Soc 2019, 141: 13987-13994.
Kobayashi K, Doshida Y, Mizuno Y, et al. Possibility of cofiring a nickel inner electrode in a (Na0.5K0.5)NbO3-LiF piezoelectric actuator. Jpn J Appl Phys 2013, 52: 09KD07.
Fisher JG, Kang SJL. Microstructural changes in (K0.5Na0.5)NbO3 ceramics sintered in various atmospheres. J Eur Ceram Soc 2009, 29: 2581-2588.
Vendrell X, García JE, Rubio-Marcos F, et al. Exploring different sintering atmospheres to reduce nonlinear response of modified KNN piezoceramics. J Eur Ceram Soc 2013, 33: 825-831.
Teranishi S, Suzuki M, Noguchi Y, et al. Giant strain in lead-free (Bi0.5Na0.5)TiO3-based single crystals. Appl Phys Lett 2008, 92: 182905.
Qiao XS, Chen XM, Lian HL, et al. Microstructure and electrical properties of nonstoichiometric 0.94(Na0.5Bi0.5+x)TiO3-0.06BaTiO3 lead-free ceramics. J Am Ceram Soc 2016, 99: 198-205.
Saiful Islam M. Ionic transport in ABO3 perovskite oxides: A computer modelling tour. J Mater Chem 2000, 10: 1027-1038.
Kobayashi K, Doshida Y, Mizuno Y, et al. A route forwards to narrow the performance gap between PZT and lead-free piezoelectric ceramic with low oxygen partial pressure processed (Na0.5K0.5)NbO3. J Am Ceram Soc 2012, 95: 2928-2933.
Watanabe Y, Sumida K, Yamada S, et al. Effect of Mn-doping on the piezoelectric properties of (K0.5Na0.5)(Nb0.67Ta0.33)O3 lead-free ceramics. Jpn J Appl Phys 2008, 47: 3556-3558.
Mgbemere HE, Herber RP, Schneider GA. Effect of MnO2 on the dielectric and piezoelectric properties of alkaline niobate based lead free piezoelectric ceramics. J Eur Ceram Soc 2009, 29: 1729-1733.
Lin DM, Kwok KW, Tian HY, et al. Phase transitions and electrical properties of (Na1-xKx)(Nb1-ySby)O3 lead-free piezoelectric ceramics with a MnO2 sintering aid. J Am Ceram Soc 2007, 90: 1458-1462.
Kizaki Y, Noguchi Y, Miyayama M. Defect control for low leakage current in K0.5Na0.5NbO3 single crystals. Appl Phys Lett 2006, 89: 142910.
Noguchi Y, Miyayama M. Effect of Mn doping on the leakage current and polarization properties in K0.14Na0.86NbO3 ferroelectric single crystals. J Ceram Soc Jpn 2010, 118: 711-716.
Kawada S, Hayashi H, Ishii H, et al. Potassium sodium niobate-based lead-free piezoelectric multilayer ceramics Co-fired with nickel electrodes. Materials 2015, 8: 7423-7438.
Moulder JF, Stickle WF, Sobol PE, et al. Handbook of X-ray Photoelectron Spectroscopy: A Reference Book of Standard Spectra for Identification and Interpretation of XPS Data. Minnesota (USA): Physical Electronics, 1992.
Shannon RD. Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Cryst A 1976, 32: 751-767.
Rafiq MA, Tkach A, Costa ME, et al. Defects and charge transport in Mn-doped K0.5Na0.5NbO3 ceramics. Phys Chem Chem Phys 2015, 17: 24403-24411.
Li JF, Wang K, Zhu FY, et al. (K,Na)NbO3-based lead-free piezoceramics: Fundamental aspects, processing technologies, and remaining challenges. J Am Ceram Soc 2013, 96: 3677-3696.
Zhang BY, Wu JG, Wang XP, et al. Rhombohedral- orthorhombic phase coexistence and electrical properties of Ta and BaZrO3 co-modified (K,Na)NbO3 lead-free ceramics. Curr Appl Phys 2013, 13: 1647-1650.
Cheng XX, Zhou DX, Fu QY, et al. Effect of reoxidation annealing on the PTCR behaviour of multilayer Nb5+-doped BaTiO3 ceramics with a Ni internal electrode. J Phys D: Appl Phys 2012, 45: 385306.
Niimi H, Mihara K, Sakabe Y, et al. Influence of Ba/Ti ratio on the positive temperature coefficient of resistivity characteristics of Ca-doped semiconducting BaTiO3 fired in reducing atmosphere and reoxidized in air. J Am Ceram Soc 2007, 90: 1817-1821.
Gao C, Fu QY, Zhou DX, et al. Nanocrystalline semiconducting donor-doped BaTiO3 ceramics for laminated PTC thermistor. J Eur Ceram Soc 2017, 37: 1523-1528.
Sun Y, Liu HX, Hao H, et al. Effect of oxygen vacancy on electrical property of acceptor doped BaTiO3-Na0.5Bi0.5TiO3-Nb2O5 X8R systems. J Am Ceram Soc 2016, 99: 3067-3073.
Yoon SH, Randall CA, Hur KH. Effect of acceptor (Mg) concentration on the resistance degradation behavior in acceptor (Mg)-doped BaTiO3 bulk ceramics: I. impedance analysis. J Am Ceram Soc 2009, 92: 1758-1765.
Robels U, Arlt G. Domain wall clamping in ferroelectrics by orientation of defects. J Appl Phys 1993, 73: 3454-3460.
Jin L, Li F, Zhang SJ. Decoding the fingerprint of ferroelectric loops: Comprehension of the material properties and structures. J Am Ceram Soc 2014, 97: 1-27.
Zhao ZH, Dai YJ, Li XL, et al. The evolution mechanism of defect dipoles and high strain in MnO2-doped KNN lead-free ceramics. Appl Phys Lett 2016, 108: 172906.
Feng ZY, Ren XB. Aging effect and large recoverable electrostrain in Mn-doped KNbO3-based ferroelectrics. Appl Phys Lett 2007, 91: 032904.
Ge HY, Hou YD, Rao X, et al. The investigation of depoling mechanism of densified KNbO3 piezoelectric ceramic. Appl Phys Lett 2011, 99: 032905.
Fu J, Zuo RZ. Giant electrostrains accompanying the evolution of a relaxor behavior in Bi(Mg,Ti)O3-PbZrO3- PbTiO3 ferroelectric ceramics. Acta Mater 2013, 61: 3687-3694.
Li P, Chen XQ, Wang FF, et al. Microscopic insight into electric fatigue resistance and thermally stable piezoelectric properties of (K,Na)NbO3-based ceramics. ACS Appl Mater Interfaces 2018, 10: 28772-28779.
Luo ZH, Glaum J, Granzow T, et al. Bipolar and unipolar fatigue of ferroelectric BNT-based lead-free piezoceramics. J Am Ceram Soc 2011, 94: 529-535.
Journal of Advanced Ceramics
Pages 820-831
Cite this article:
CEN Z, BIAN S, XU Z, et al. Simultaneously improving piezoelectric properties and temperature stability of Na0.5K0.5NbO3 (KNN)-based ceramics sintered in reducing atmosphere. Journal of Advanced Ceramics, 2021, 10(4): 820-831.








Web of Science






Received: 11 January 2021
Revised: 20 February 2021
Accepted: 10 March 2021
Published: 05 August 2021
© The Author(s) 2021

This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made.

The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

To view a copy of this licence, visit