Structures, dielectric and ferroelectric properties of Sr2-xCaxNaNb5O15 lead-free ceramics

Journal of Materials Research volume 27, pages979–984(2012)Cite this article

Abstract

The high-density tungsten bronze (TB) Sr2-xCaxNaNb5O15 (SCNN, 0.05 ≤ x ≤ 030) lead-free ceramics were prepared by two-step solid-state reaction method. With increasing Ca2+ substitution, the crystal structure of SCNN ceramics slightly distorted from the TB tetragonal phase and became orthorhombic phase at room temperature. The smaller ionic radius of Ca2+ (1.34Å) compared with that of Sr2+ (1.44Å) contributed to the shrinkage of the crystal structure. Dielectric spectra of all compositions displayed two phase transitions: the ferroelastic orthorhombic to ferroelectric tetragonal phase transition (Te) at lower temperatures, and the ferroelectric to paraelectric phase transition (Tc) at higher temperatures. With increasing Ca2+ substitution, Te and Tc shifted towards higher temperature regions, while the maximum values of dielectric constant (εme and εm), Pr, Ec and d33 increased at first and then decreased. The ceramics with most homogeneous microstructure and highest density were obtained at x = 0.15, resulting in optimized properties.

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References

  1. 1.

    K. Kakimoto, T. Yoshifuji, and H. Ohsato: Densification of tungsten-bronze KBa2Nb5O15 lead-free piezoelectric ceramics. J. Eur. Ceram. Soc. 27, 4111 (2007).

    CAS  Article  Google Scholar 

  2. 2.

    Md. Ahamad Mohiddon and K.L. Yadava: Structural and dielectric properties of (Li0.5Na0.5) doped strontium barium niobate. J. Appl. Phys. 101, 094101 (2007).

    Article  Google Scholar 

  3. 3.

    S.M. Ke, H.Q. Fan, H.T. Huang, H.L.W. Chan, and S.H. Yu: Dielectric, ferroelectric properties, and grain growth of CaxBa1−xNb2O6 ceramics with tungsten-bronzes structure. J. Appl. Phys. 104, 024101 (2008).

    Article  Google Scholar 

  4. 4.

    L.L. Wei, Z.P. Yang, R. Gu, and H.M. Ren: The phase formation, microstructure and electric properties of tungsten bronze ferroelectric Sr2NaNb5O15 ceramics. J. Am. Ceram. Soc. 93, 1984 (2010).

    Article  Google Scholar 

  5. 5.

    T.T. Fang and T.Y. Chiu: Polarization dynamics of polar nano-regions in Sr0.5Ba0.5Nb2O6 doped with combinations of Ce and Cr. Acta Mater. 59, 1692 (2011).

    CAS  Article  Google Scholar 

  6. 6.

    R.R. Neurgaonkar, J.R. Oliver, W.K. Copy, L.E. Cross, and D. Viehland: Piezoelectricity in tungsten bronze crystals. Ferroelectr. 160, 265 (1994).

    CAS  Article  Google Scholar 

  7. 7.

    T. Kimura, S. Miyamoto, and T. Yamaguchi: Microstructure development and dielectric properties of potassium strontium niobate ceramics. J. Am. Ceram. Soc. 73, 127 (1990).

    CAS  Article  Google Scholar 

  8. 8.

    H.Y. Lee and R. Freer: Abnormal grain growth and liquid-phase sintering in Sr0.6Ba0.4Nb2O6 (SBN40) ceramics. J. Mater. Sci. 33, 1703 (1998).

    CAS  Article  Google Scholar 

  9. 9.

    L.L. Wei, Z.P. Yang, Y.F. Chang, and R. Gu: Effect of seeding Sr2KNb5O15 on the phase formation and microstructural development in reactive sintering of Sr2NaNb5O15 ceramics. J. Am. Ceram. Soc. 91, 1077 (2008).

    CAS  Article  Google Scholar 

  10. 10.

    R.J. Xie and Y. Akimune: Lead-free piezoelectric ceramics in the (1-x) Sr2NaNb5O15-xCa2NaNb5O15 (x = 0.05-0.35) system. J. Mater. Chem. 12, 3156 (2002).

    CAS  Article  Google Scholar 

  11. 11.

    R.J. Xie, Y. Akimune, K. Matsuo, T. Sugiyama, N. Hirosaki, and T. Sekiya: Dielectric and ferroelectric properties of tetragonal tungsten bronze Sr2-xCaxNaNb5O15 (x = 0.05-0.35) ceramics. Appl. Phys. Lett. 80, 835 (2002).

    CAS  Article  Google Scholar 

  12. 12.

    R.J. Xie, Y. Akimune, R.P. Wang, and N. Hirosaki: Spark plasma sintering of tungsten bronze Sr2-xCaxNaNb5O15 (x = 0.1) piezoelectric ceramics: II. Electrical properties. J. Am. Ceram. Soc. 85, 2731 (2002).

    CAS  Article  Google Scholar 

  13. 13.

    L.L. Wei, Z.P. Yang, H.M. Ren, and X.B. Chen: Phase transitional behavior and electrical properties of Sr2K0.1Na0.9Nb5-xTaxO15 ceramics. J. Am. Ceram. Soc. 93, 3986 (2010).

    CAS  Article  Google Scholar 

  14. 14.

    L.L. Wei, Z.P. Yang, R. Gu, and H. Pan: Role of structural changes in dielectric, ferroelectric properties of Sr2KxNa1−xNb5O15 lead-free ceramics. Mater. Chem. Phys. 126, 836 (2011).

    CAS  Article  Google Scholar 

  15. 15.

    A. Simon and J. Ravez: Solid-state chemistry and non-linear properties of tetragonal tungsten bronzes materials. C.R. Chim. 9, 1268 (2006).

    CAS  Article  Google Scholar 

Download references

Acknowledgments

This work was supported by National Science Foundation of China (NSFC) (Grant No. 20771070), the Fundamental Research Funds for the Central Universities (Program No. 2010ZYGX011), and Natural Science Research Program of Shaanxi Province (Grant No. 2009JZ003).

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  1. Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Materials Science, Shaanxi Normal University, Xi’an 710062, Shaanxi, P.R. China

    Lingling Wei, Zupei Yang, Xiaokun Han & Zhaohu Li

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  1. Lingling Wei
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  2. Zupei Yang
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Correspondence to Zupei Yang.

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Wei, L., Yang, Z., Han, X. et al. Structures, dielectric and ferroelectric properties of Sr2-xCaxNaNb5O15 lead-free ceramics. Journal of Materials Research 27, 979–984 (2012). https://doi.org/10.1557/jmr.2012.32

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