Structure and temperature-dependent phase transitions of lead-free Bi1/2Na1/2TiO3–Bi1/2K1/2TiO3–K0.5Na0.5NbO3 piezoceramics


Structure and phase transitions of (1 − y)((1 − x)Bi1/2Na1/2TiO3xBi1/2K1/2TiO3)–yK0.5Na0.5NbO3 (x; y) piezoceramics (0.1 ≤ x ≤ 0.4; 0 ≤ y ≤ 0.05) were investigated by transmission electron microscopy, neutron diffraction, temperature-dependent x-ray diffraction, and Raman spectroscopy. The local crystallographic structure at room temperature (RT) does not change by adding K0.5Na0.5NbO3 to Bi1/2Na1/2TiO3xBi1/2K1/2TiO3 for x = 0.2 and 0.4. The average crystal structure and microstructure on the other hand develop from mainly long-range polar order with ferroelectric domains to short-range order with polar nanoregions displaying a more pronounced relaxor character. The (0.1; 0) and (0.1; 0.02) compositions exhibit monoclinic Cc space group symmetry, which transform into Cc + P4bm at 185 and 130 °C, respectively. This high temperature phase is stable at RT for the morphotropic phase boundary compositions of (0.1; 0.05) and all compositions with x = 0.2. For the compositions of (0.1; 0) and (0.1; 0.02), local structural changes on heating are evidenced by Raman; for all other compositions, changes in the long-range average crystal structure were observed.

This is a preview of subscription content, access via your institution.

FIG. 1.
FIG. 2.
FIG. 3.
FIG. 4.
FIG. 5.
FIG. 6.
FIG. 7.
FIG. 8.
FIG. 9.
FIG. 10.
FIG. 11.
FIG. 12.


  1. 1.

    RöJ. del, W. Jo, K.T.P. Seifert, E.M. Anton, T. Granzow, and D. Damjanovic: Perspective on the development of lead-free piezoceramics. J. Am. Ceram. Soc. 92, 1153 (2009).

    Article  CAS  Google Scholar 

  2. 2.

    T. Takenaka, H. Nagata, and Y. Hiruma: Current developments and prospective of lead-free piezoelectric ceramics. Jpn. J. Appl. Phys. 47, 3787 (2008).

    CAS  Article  Google Scholar 

  3. 3.

    E. Aksel and J.L. Jones: Advances in lead-free piezoelectric materials for sensors and actuators. Sensors 10, 1935 (2010).

    CAS  Article  Google Scholar 

  4. 4.

    B. Jaffe, W.R. Cook, and H. Jaffe, editors: Piezoelectric Ceramics (Academic Press, London, 1971).

    Google Scholar 

  5. 5.

    A.B. Kounga, S.T. Zhang, W. Jo, T. Granzow, and RöJ. del: Morphotropic phase boundary in (1-x)Bi0.5Na0.5TiO3-xK0.5Na0.5NbO3 lead-free piezoceramics. Appl. Phys. Lett. 92, 222902 (2008).

    Article  CAS  Google Scholar 

  6. 6.

    T. Takenaka, K. Maruyama, and K. Sakata: (Bi1/2Na1/2)TiO3-BaTiO3 system for lead-free piezoelectric ceramics. Jpn. J. Appl. Phys., Part 1 30, 2236 (1991).

    CAS  Article  Google Scholar 

  7. 7.

    O. Elkechai, M. Manier, and J.P. Mercurio: Na0.5Bi0.5TiO3-K0.5Bi0.5TiO3 (NBT-KBT) system: A structural and electrical study. Phys. Status Solidi A 157, 499 (1996).

    Article  Google Scholar 

  8. 8.

    A. Sasaki, T. Chiba, Y. Mamiya, and E. Otsuki: Dielectric and piezoelectric properties of (Bi1/2Na1/2)TiO3-(Bi0.5K0.5)TiO3 systems. Jpn. J. Appl. Phys., Part 1 38, 5564 (1999).

    CAS  Article  Google Scholar 

  9. 9.

    H. Nagata, M. Yoshida, Y. Makiuchi, and T. Takenaka: Large piezoelectric constant and high Curie temperature of lead-free piezoelectric ceramic ternary system based on bismuth sodium titanate-bismuth potassium titanate-barium titanate near the morphotropic phase boundary. Jpn. J. Appl. Phys., Part 1 42, 7401 (2003).

    CAS  Article  Google Scholar 

  10. 10.

    S.T. Zhang, A.B. Kounga, E. Aulbach, H. Ehrenberg, and RöJ. del: Giant strain in lead-free piezoceramics Bi0.5Na0.5TiO3-BaTiO3-K0.5Na0.5NbO3 system. Appl. Phys. Lett. 91, 112906 (2007).

    Article  CAS  Google Scholar 

  11. 11.

    K.T.P. Seifert, W. Jo, and RöJ. del: Temperature-insensitive large strain of (Bi1/2Na1/2)TiO3-(Bi1/2K1/2)TiO3-(K0.5Na0.5)NbO3 lead-free piezoceramics. J. Am. Ceram. Soc. 93, 1392 (2010).

    CAS  Google Scholar 

  12. 12.

    A. Singh and R. Chatterjee: Structural, electrical, and strain properties of stoichiometric 1-x - y(Bi0.5Na0.5)TiO3 - x(Bi0.5K0.5TiO3) - y(Na0.5K0.5)NbO3 solid solutions. J. Appl. Phys. 109, 024105 (2011).

    Article  CAS  Google Scholar 

  13. 13.

    E.M. Anton, W. Jo, J. Trodahl, D. Damjanovic, and RöJ. del: Effect of K0.5Na0.5NbO3 on properties at and off the morphotropic phase boundary in Bi1/2Na1/2TiO3-Bi1/2K1/2TiO3 ceramics. Jpn. J. Appl. Phys. 50, 055802 (2011).

    Article  CAS  Google Scholar 

  14. 14.

    G.O. Jones, J. Kreisel, and P.A. Thomas: A structural study of the (Na1-xKx)0.5Bi0.5TiO3 perovskite series as a function of substitution (x) and temperature. Powder Diffr. 17, 301 (2002).

    CAS  Article  Google Scholar 

  15. 15.

    A.M. Glazer: Classification of tilted octahedra in perovskites. Acta Crystallogr., Sect. B: Struct. Sci. 28, 3384 (1972).

    CAS  Article  Google Scholar 

  16. 16.

    W. Zhao, H.P. Zhou, Y.K. Yan, and D. Liu: Morphotropic phase boundary study of the BNT-BKT lead-free piezoelectric ceramics. Key Eng. Mater. 368–372, 1908 (2008).

    Article  Google Scholar 

  17. 17.

    Z. Yang, B. Liu, L. Wei, and Y. Hou: Structure and electrical properties of (1-x)Bi0.5Na0.5TiO3-xBi0.5K0.5TiO3 ceramics near morphotropic phase boundary. Mater. Res. Bull. 43, 81 (2008).

    CAS  Article  Google Scholar 

  18. 18.

    M. Otonicar, S.D. Skapin, M. Spreitzer, and D. Suvorov: Compositional range and electrical properties of the morphotropic phase boundary in the Na0.5Bi0.5TiO3-K0.5Bi0.5TiO3 system. J. Eur. Ceram. Soc. 30, 971 (2010).

    CAS  Article  Google Scholar 

  19. 19.

    C.W. Tai, S.H. Choy, and H.L.W. Chan: Ferroelectric domain morphology evolution and octahedral tilting in lead-free (Bi1/2Na1/2)TiO3-(Bi1/2K1/2)TiO3-(Bi1/2Li1/2)TiO3-BaTiO3 ceramics at different temperatures. J. Am. Ceram. Soc. 91, 3335 (2008).

    CAS  Article  Google Scholar 

  20. 20.

    C.W. Tai and Y. Lereah: Nanoscale oxygen octahedral tilting in 0.90(Bi1/2Na1/2)TiO3-0.05(Bi1/2K1/2)TiO3-0.05BaTiO3 lead-free perovskite piezoelectric ceramics. Appl. Phys. Lett. 95, 062901 (2009).

    Article  CAS  Google Scholar 

  21. 21.

    M. Otonicar, S.D. Skapin, and B. Jancar: TEM analyses of the local crystal and domain structures in (Na1-xKx)0.5Bi0.5TiO3 perovskite ceramics. IEEE Trans. Ultrason., Ferroelectr. Freq. Control 58, 1928 (2011).

    Article  Google Scholar 

  22. 22.

    D.I. Woodward and I.M. Reaney: Electron diffraction of tilted perovskites. Acta Crystallogr., Sect. B: Struct. Sci. B61, 387 (2005).

    CAS  Article  Google Scholar 

  23. 23.

    S. Gorfman and P.A. Thomas: Evidence for a non-rhombohedral average structure in the lead-free piezoelectric material Na0.5Bi0.5TiO3. J. Appl. Crystallogr. 43, 1409 (2010).

    CAS  Article  Google Scholar 

  24. 24.

    E. Aksel, J.S. Forrester, J.L. Jones, P.A. Thomas, K. Page, and M.R. Suchomel: Monoclinic crystal structure of polycrystalline Na0.5Bi0.5TiO3. Appl. Phys. Lett. 98, 152901 (2011).

    Article  CAS  Google Scholar 

  25. 25.

    I. Levin, I.M. Reaney, E.-M. Anton, W. Jo, J. Rödel, J. Pokorny, L.A. Schmitt, H.-J. Kleebe, M. Hinterstein, J. Trodahl, and J.L. Jones: Local Structure, Pseudo-Symmetry, and Phase Transitions in Na1/2Bi1/2TiO3-K1/2Bi1/2TiO3 Ceramics. Phys. Rev. B (2012, submitted).

    Google Scholar 

  26. 26.

    Z.H. Yao, H.X. Liu, L. Chen, and M.H. Cao: Morphotropic phase boundary and piezoelectric properties of (Bi1/2Na1/2)1-x(Bi1/2K1/2)xTiO3-0.03(Na0.5K0.5)NbO3 ferroelectric ceramics. Mater. Lett. 63, 547 (2009).

    CAS  Article  Google Scholar 

  27. 27.

    W. Jo, J.E. Daniels, J.L. Jones, X. Tan, P.A. Thomas, D. Damjanovic, and J. Rödel: Evolving morphotropic phase boundary in lead-free (Bi1/2Na1/2)TiO3–BaTiO3 piezoceramics. J. Appl. Phys. 109, 014110 (2011).

    Article  CAS  Google Scholar 

  28. 28.

    B. van Wylie-Eerd, D. Damjanovic, N. Klein, N. Setter, and J. Trodahl: Structural complexity of (Na0.5Bi0.5)TiO3-BaTiO3 as revealed by Raman spectroscopy. Phys. Rev. B 82, 104112 (2010).

    Article  CAS  Google Scholar 

  29. 29.

    G. Miehe: Program for Interpreting Electron Diffraction Patterns (PIEP). Version 7.12 (Institute for Materials Science, Technische Universität Darmstadt, Germany, 2002).

    Google Scholar 

  30. 30.

    T. Roisnel and J. Rodriguez-Carvajal: WinPLOTR: A windows tool for powder diffraction pattern analysis. Mater. Sci. Forum 378-381, 118 (2001).

    CAS  Article  Google Scholar 

  31. 31.

    J. Fousek and V. Janovec: The orientation of domain walls in twinned ferroelectric crystals. Phys. Rev. B 40, 135 (1969).

    CAS  Google Scholar 

  32. 32.

    X.H. Dai, Z. Xu, J.F. Li, and D. Viehland: Effects of lanthanum modification on rhombohedral Pb(Zr1-xTix)O3 ceramics.1. Transformation from normal to relaxor ferroelectric behaviors. J. Mater. Res. 11, 618 (1996).

    CAS  Article  Google Scholar 

  33. 33.

    G. Honjo, S. Kodera, and N. Kitamura: Diffuse streak diffraction patterns from single crystals. I. General discussion and aspects of electron diffraction diffuse streak patterns. J. Phys. Soc. Jpn. 19, 351 (1964).

    CAS  Article  Google Scholar 

  34. 34.

    T.R. Welberry: Diffuse X-Ray Scattering and Models of Disorder (Oxford University Press, New York, 2004).

    Google Scholar 

  35. 35.

    J.E. Daniels, W. Jo, J. Rodel, D. Rytz, and W. Donner: Structural origins of relaxor behavior in a 0.96(Bi1/2Na1/2)TiO3-0.04BaTiO3 single crystal under electric field. Appl. Phys. Lett. 98, 252904 (2011).

    Article  CAS  Google Scholar 

  36. 36.

    I. Jeong, C.Y. Park, D.J. Kim, S.h. Kim, B.K. Moon, I.W. Kim, and C.W. Ahn: Neutron total scattering studies on A-site disorder in lead-free ferroelectric Bi0.5(Na1–xKx)0.5TiO3. Z. Kristallogr. 226, 150 (2011).

    CAS  Article  Google Scholar 

  37. 37.

    E. Aksel, J.S. Forrester, B. Kowalski, J.L. Jones, and P.A. Thomas: Phase transition sequence in sodium bismuth titanate observed using high-resolution x-ray diffraction. Appl. Phys. Lett. 99, 222901 (2011).

    Article  CAS  Google Scholar 

  38. 38.

    H.D. Xie, L. Jin, D.Z. Shen, X.Q. Wang, and G.Q. Shen: Morphotropic phase boundary, segregation effect and crystal growth in the NBT-KBT system. J. Cryst. Growth 311, 3626 (2009).

    CAS  Article  Google Scholar 

  39. 39.

    E. Aksel, J.S. Forrester, B. Kowalski, M. Deluca, D. Damjanovic, and J.L. Jones: Structure and properties of Fe-modified Na0.5Bi0.5TiO3 at ambient and elevated temperature. Phys. Rev. B 85, (2012).

  40. 40.

    E.M. Anton, W. Jo, D. Damjanovic, and RöJ. del: Determination of depolarization temperature of (Bi1/2Na1/2)TiO3-based lead-free piezoceramics. J. Appl. Phys. 110, 094108 (2011).

    Article  CAS  Google Scholar 

  41. 41.

    M. Davies, E. Aksel, and J.L. Jones: Enhanced high-temperature piezoelectric coefficients and thermal stability of Fe- and Mn-substituted Na0.5Bi0.5TiO3 ceramics. J. Am. Ceram. Soc. 94, 1314 (2011).

    CAS  Article  Google Scholar 

  42. 42.

    J. Frantti, S. Ivanov, S. Eriksson, RundlöH. f, V. Lantto, J. Lappalainen, and M. Kakihana: Phase transitions of Pb(ZrxTi1-x)O3 ceramics. Phys. Rev. B 66, 064108 (2002).

    Article  CAS  Google Scholar 

  43. 43.

    M. Hinterstein, M. Knapp, M. Holzel, W. Jo, A. Cervellino, H. Ehrenberg, and H. Fuess: Field-induced phase transition in Bi1/2Na1/2TiO3-based lead-free piezoelectric ceramics. J. Appl. Crystallogr. 43, 1314 (2010).

    CAS  Article  Google Scholar 

  44. 44.

    L.A. Schmitt, M. Hinterstein, H.J. Kleebe, and H. Fuess: Comparative study of two lead-free piezoceramics using diffraction techniques. J. Appl. Crystallogr. 43, 805 (2010).

    CAS  Article  Google Scholar 

  45. 45.

    J. Peng and L.A. Bursill: Polar and chemical domain structures of lead scandium tantalate (PST). Mod. Phys. Lett. B 7, 609 (1993).

    CAS  Article  Google Scholar 

  46. 46.

    D.H. Zhou, G.L. Hoatson, R.L. Vold, and F. Fayon: Local structure in perovskite relaxor ferroelectrics by 207Pb NMR. Phys. Rev. B 69, 134104 (2004).

    Article  CAS  Google Scholar 

  47. 47.

    B.J. Maier, R.J. Angel, W.G. Marshall, B. Mihailova, C. Paulmann, J.M. Engel, M. Gospodinov, A.M. Welsch, D. Petrova, and U. Bismayer: Octahedral tilting in Pb-based relaxor ferroelectrics at high pressure. Acta Crystallogr., Sect. B: Struct. Sci. 66, 280 (2010).

    CAS  Article  Google Scholar 

  48. 48.

    G.O. Jones and P.A. Thomas: Investigation of the structure and phase transitions in the novel A-site substituted distorted perovskite compound Na1/2Bi1/2TiO3. Acta Crystallogr., Sect. B: Struct. Sci. 58, 168 (2002).

    CAS  Article  Google Scholar 

  49. 49.

    J. Kreisel, P. Bouvier, B. Dkhil, P.A. Thomas, A.M. Glazer, T.R. Welberry, B. Chaabane, and M. Mezouar: High-pressure x-ray scattering of oxides with a nanoscale local structure: Application to Na1/2Bi1/2TiO3. Phys. Rev. B 68, 014113 (2003).

    Article  CAS  Google Scholar 

  50. 50.

    S. Said and J.P. Mercurio: Relaxor behaviour of low lead and lead free ferroelectric ceramics of the Na1/2Bi1/2TiO3-PbTiO3 and Na1/2Bi1/2TiO3-K0.5Bi0.5TiO3 systems. J. Eur. Ceram. Soc. 21, 1333 (2001).

    CAS  Article  Google Scholar 

  51. 51.

    W. Jo, S. Schaab, E. Sapper, L.A. Schmitt, H.J. Kleebe, A.J. Bell, and J. Rodel: On the phase identity and its thermal evolution of lead free (Bi1/2Na1/2)TiO3-6 mol% BaTiO3. J. Appl. Phys. 110, 074106 (2011).

    Article  CAS  Google Scholar 

Download references


E-M.A. acknowledges support for this work by the LOEWE-center AdRIA on adaptronics. M.H. acknowledges support from the BMBF (Bundesministerium für Bildung und Forschung) under Grant No. 05K10ODA. J.L.J. and B.K. acknowledge partial support by the U.S. National Science Foundation (NSF) under award number DMR-0746902 and the U.S. Department of the Army under W911NF-09-1-0435. Use of the Advanced Photon Source was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. The authors thank Robert Dittmer and Matthew Suchomel for assistance with the x-ray measurements, Thomas Hansen for the assistance with neutron measurements, Lars Riekehr for TEM specimen preparation, and Michael Wagner for assistance with Raman spectroscopy and sample preparation.

Author information



Corresponding author

Correspondence to Eva-Maria Anton.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Anton, EM., Schmitt, L.A., Hinterstein, M. et al. Structure and temperature-dependent phase transitions of lead-free Bi1/2Na1/2TiO3–Bi1/2K1/2TiO3–K0.5Na0.5NbO3 piezoceramics. Journal of Materials Research 27, 2466–2478 (2012).

Download citation