Skip to main content
SpringerLink
Log in

Effects of Ge4+ acceptor dopant on sintering and electrical properties of (K0.5Na0.5)NbO3 lead-free piezoceramics

  • Research Article
  • Published:
Frontiers of Materials Science Aims and scope Submit manuscript

Abstract

Lead-free (K0.5Na0.5)(Nb1-xGe x )O3 (KNN-xGe, where x = 0-0.01) piezoelectric ceramics were prepared by conventional ceramic processing. The effects of Ge4+ cation doping on the phase compositions, microstructure and electrical properties of KNN ceramics were studied. SEM images show that Ge4+ cation doping improved the sintering and promoted the grain growth of the KNN ceramics. Dielectric and ferroelectric measurements proved that Ge4+ cations substituted Nb5+ ions as acceptors, and the Curie temperature (TC) shows an almost linear decrease with increasing the Ge4+ content. Combining this result with microstructure observations and electrical measurements, it is concluded that the optimal sintering temperature for KNN-xGe ceramics was 1020°C. Ge4+ doping less than 0.4 mol.%can improve the compositional homogeneity and piezoelectric properties of KNN ceramics. The KNN-xGe ceramics with x = 0.2% exhibited the best piezoelectric properties: piezoelectric constant d33 = 120 pC/N, planar electromechanical coupling coefficient kp = 34.7%, mechanical quality factor Qm = 130, and tanδ = 3.6%.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

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

    Book  Google Scholar 

  2. Ahmad Safari E K A. Piezoelectric and Acoustic Materials for Transducer Applications. New York: Springer, 2008

    Book  Google Scholar 

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

    Article  Google Scholar 

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

    Article  Google Scholar 

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

    Article  Google Scholar 

  6. Li J F, Wang K, Zhu F Y, et al. (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

    Article  Google Scholar 

  7. 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

    Article  Google Scholar 

  8. Matsubara M, Yamaguchi T, Kikuta K, et al. Sinterability and piezoelectric properties of (K,Na)NbO3 ceramics with novel sintering aid. Japanese Journal of Applied Physics, 2004, 43(10): 7159–7163

    Article  Google Scholar 

  9. Matsubara M, Yamaguchi T, Kikuta K, et al. Sintering and piezoelectric properties of potassium sodium niobate ceramics with newly developed sintering aid. Japanese Journal of Applied Physics, 2005, 44(1A): 258–263

    Article  Google Scholar 

  10. Matsubara M, Yamaguchi T, Sakamoto W, et al. Processing and piezoelectric properties of lead-free (K,Na)(Nb,Ta)O3 ceramics. Journal of the American Ceramic Society, 2005, 88(5): 1190–1196

    Article  Google Scholar 

  11. Zuo R Z, Rodel J, Chen R Z, et al. Sintering and electrical properties of lead-free Na0.5K0.5NbO3 piezoelectric ceramics. Journal of the American Ceramic Society, 2006, 89(6): 2010–2015

    Article  Google Scholar 

  12. Lin D M, Kwok K W, Chan H L W. Double hysteresis loop in Cudoped K0.5Na0.5NbO3 lead-free piezoelectric ceramics. Applied Physics Letters, 2007, 90(23): 232903

    Article  Google Scholar 

  13. Bernard J, Bencan A, Rojac T, et al. Low-temperature sintering of K0.5Na0.5NbO3 ceramics. Journal of the American Ceramic Society, 2008, 91(7): 2409–2411

    Article  Google Scholar 

  14. Ahn C W, Nahm S, Karmarkar M, et al. Effect of CuO and MnO2 on sintering temperature, microstructure, and piezoelectric properties of 0.95(K0.5Na0.5)NbO3–0.05BaTiO3 ceramics. Materials Letters, 2008, 62(20): 3594–3596

    Article  Google Scholar 

  15. Mgbemere H E, Herber R P, Schneider G A. Effect of MnO2 on the dielectric and piezoelectric properties of alkaline niobate based lead free piezoelectric ceramics. Journal of the European Ceramic Society, 2009, 29(9): 1729–1733

    Article  Google Scholar 

  16. Rubio-Marcos F, Romero J J, Navarro-Rojero MG, et al. Effect of ZnO on the structure, microstructure and electrical properties of KNN-modified piezoceramics. Journal of the European Ceramic Society, 2009, 29(14): 3045–3052

    Article  Google Scholar 

  17. Zhou J J, Cheng L Q, Wang K, et al. Low-temperature sintering of (K,Na)NbO3-based lead-free piezoceramics with addition of LiF. Journal of the European Ceramic Society, 2014, 34(5): 1161–1167

    Article  Google Scholar 

  18. Chen K P, Zhang F L, Zhou J Q, et al. Effect of borax addition on sintering and electrical properties of (K0.5Na0.5)NbO3 lead-free piezoceramics. Ceramics International, 2015, 41(8): 10232–10236

    Article  Google Scholar 

  19. Chen K P, Zhou J Q, Zhang F L, et al. Screening sintering aids for (K0.5Na0.5)NbO3 ceramics. Journal of the American Ceramic Society, 2015, 98(6): 1698–1701

    Article  Google Scholar 

  20. Chen K P, Zhang F L, Jiao Y L, et al. Effects of GeO2 addition on sintering and properties of (K0.5Na0.5)NbO3 ceramics. Journal of the American Ceramic Society, 2016, 99(5): 1681–1686

    Article  Google Scholar 

  21. Zhao Y J, Chen Y, Chen K P. Improvement in synthesis of (K0.5Na0.5)NbO3 powders by Ge4+ acceptor doping. Frontiers of Materials Science, 2016, 10(4): 422–427

    Article  Google Scholar 

  22. Chen K P, Zhang F L, Li D S, et al. Acceptor doping effects in (K0.5Na0.5)NbO3 lead-free piezoelectric ceramics. Ceramics International, 2016, 42(2): 2899–2903

    Article  Google Scholar 

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

    Article  Google Scholar 

  24. Kumar P, Pattanaik M, Sonia. Synthesis and characterizations of KNN ferroelectric ceramics near 50/50 MPB. Ceramics International, 2013, 39(1): 65–69

    Article  Google Scholar 

Download references

Acknowledgements

The authors thank Jianqiang Zhou for his technical help with SEM measurements. This work was supported by the National Natural Science Foundation of China (Grant No. 21371056) and the Fundamental Research Funds for the Central Universities (Grant No. 2015ZZD04).

Author information

Authors and Affiliations

  1. School of Energy, Power and Mechanical Engineering, North China Electric Power University, Beijing, 102206, China

    Kepi Chen & Yanlin Jiao

Authors
  1. Kepi Chen
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Yanlin Jiao
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Kepi Chen.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Chen, K., Jiao, Y. Effects of Ge4+ acceptor dopant on sintering and electrical properties of (K0.5Na0.5)NbO3 lead-free piezoceramics. Front. Mater. Sci. 11, 59–65 (2017). https://doi.org/10.1007/s11706-017-0371-2

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11706-017-0371-2

Keywords

Search

Navigation