Journal of Materials Science

, Volume 51, Issue 19, pp 9031–9042 | Cite as

Effect of alkaline excess on sintering, microstructural, and electrical properties of Li0.12Na0.88NbO3 ceramics

  • Supratim Mitra
  • Pankaj K. Patro
  • Ajit R. Kulkarni
Original Paper


Sintering behavior in Li0.12Na0.88NbO3 (LNN-12) ceramics has been investigated by analyzing the microstructures of the samples sintered at different temperatures (1050–1250 °C) and durations (1–6 h) to optimize the sintering conditions. An excess amount of Li2CO3 was added (1, 3, 5 mol%) to stoichiometric LNN-12 in order to compensate for the probable alkaline element loss at higher optimized sintering temperature. The addition of excess Li2CO3 into the starting materials and the effect of it on microstructure and electrical properties were investigated. Microstructural study of Li2CO3-added samples revealed abnormal grain growth, a characteristic feature of liquid phase sintering due to the low melting Li2CO3. The temperature and frequency dependence of dielectric constant shows two phase transitions in temperature dependence and low-frequency dispersion in the frequency dependence of dielectric plot. The observed frequency dispersion is attributed to dominant DC conductivity. The conduction mechanism was identified as diffusion of intrinsic Li+ ion. The room-temperature dielectric constant and loss factor were found to increase with increase in Li2CO3 addition from 160 to 690 and 0.02 to 0.04, respectively. The electrical conductivity was found to increase two orders of magnitude (10−12–10−10 Ω−1 cm−1) in Li2CO3-added samples as compared to stoichiometric composition. The results obtained here give a strong evidence of the stoichiometry–microstructure and electrical properties correlation, thus emphasizing on the importance of processing parameters to tune the desired properties in Li0.12Na0.88NbO3 ceramics.


Sintered Density Diffuse Phase Transition Abnormal Grain Growth Alkali Element Laser Diffraction Particle Size Analyzer 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



S.M. would like to thank SAIF, IIT, Bombay, for providing SEM facility.

Compliance with ethical standards

Conflict of interest

All the authors certify that they have no affiliations or involvement in any organization or entity with any financial interest or non-financial interest in the subject matter or materials discussed in this manuscript.


  1. 1.
    Henson RM, Zeyfang RR, Kiehl KV (1977) Dielectric and electromechanical properties of (Li, Na)NbO3 ceramics. J Am Ceram Soc 60:15–17CrossRefGoogle Scholar
  2. 2.
    Hardiman B, Henson RM, Reeves CP, Zeyfang RR (1976) Hot pressing of sodium lithium niobate ceramics with perovskite-type structures. Ferroelectrics 12:157–159CrossRefGoogle Scholar
  3. 3.
    Chen Q, Peng Z, Liu H, Xiao D, Zhu J, Zhu J (2010) The crystalline structure and phase-transitional behavior of (Li0.12Na0.88)(Nb1−x%Sbx%)O3 lead-free piezoelectric ceramics with high Q m. J Am Ceram Soc 93:2788–2794CrossRefGoogle Scholar
  4. 4.
    Mitra S, Kulkarni AR, Prakash O (2013) Densification behaviour and two stage master sintering curve in lithium sodium niobate ceramics. Ceram Int 39:S65–S68CrossRefGoogle Scholar
  5. 5.
    Pelton AD, Bale CW, Lin PL (1984) Calculation of phase diagrams and thermodynamic properties of 14 additive and reciprocal ternary systems containing Li2CO3, Na2CO3, K2CO3, Li2SO4, Na2SO4, K2SO4, LiOH, NaOH, and KOH. Can J Chem 62:457–474CrossRefGoogle Scholar
  6. 6.
    Maeder MD, Damjanovic D, Setter N (2004) Lead free ferroelectric materials. J Electroceram 13:385–392CrossRefGoogle Scholar
  7. 7.
    Jenko D, Malic B, Bernard JB, Cilensek J, Kosec M (2003) Synthesis and sintering of KNN 50/50 ceramics. Mater Technol 37:22–28Google Scholar
  8. 8.
    Li J-F, Wang K, Zhang B-P, Zhang L-M (2006) Ferroelectric and piezoelectric properties of fine-grained Na0.5K0.5NbO3 lead-free piezoelectric ceramics prepared by spark plasma sintering. J Am Ceram Soc 89:706–709CrossRefGoogle Scholar
  9. 9.
    Zhen Y, Li J-F (2006) Normal sintering of (K, Na)NbO3-based ceramics: influence of sintering temperature on densification, microstructure, and electrical properties. J Am Ceram Soc 89:3669–3675CrossRefGoogle Scholar
  10. 10.
    Bomlai P, Wichianrat P, Muensit S, Milne SJ (2007) Effect of calcination conditions and excess alkali carbonate on the phase formation and particle morphology of Na0.5K0.5NbO3 powders. J Am Ceram Soc 90:1650–1655CrossRefGoogle Scholar
  11. 11.
    Mitra S, Kulkarni AR, Prakash O (2013) Diffuse phase transition and electrical properties of lead-free piezoelectric (LixNa1−x)NbO3 (0.04 ≤ x ≤ 0.20) ceramics near morphotropic phase boundary. J Appl Phys 114:064106CrossRefGoogle Scholar
  12. 12.
    Cheng L-Q, Wang K, Yao F-Z, Zhu F, Li J-F (2013) Composition inhomogeneity due to alkaline volatilization in Li-modified (K, Na)NbO3 lead-free piezoceramics. J Am Ceram Soc 96:2693–2695CrossRefGoogle Scholar
  13. 13.
    Shaw NJ (1989) Densification and coarsening during solid state sintering of ceramics: a review of the models. I. Densification. Powder Metall Intl 2(8):16–21Google Scholar
  14. 14.
    Rahaman MN (2003) Ceramic processing and Sintering. Marcel Dekker, New YorkGoogle Scholar
  15. 15.
    Zhen Y, Li J-F (2007) Abnormal grain growth and new core–shell structure in (K, Na)NbO3-based lead-free piezoelectric ceramics. J Am Ceram Soc 90:3496–3502CrossRefGoogle Scholar
  16. 16.
    Patro PK, Kulkarni AR, Harendranath CS (2004) Dielectric and ferroelectric behavior of SBN50 synthesized by solid-state route using different precursors. Ceram Int 30:1405–1409CrossRefGoogle Scholar
  17. 17.
    Huanosta A, West AR (1987) The electrical properties of ferroelectric LiTaO3 and its solid solutions. J Appl Phys 61:5386CrossRefGoogle Scholar
  18. 18.
    Nobre MAL, Lanfredi S (2001) Phase transition in sodium lithium niobate polycrystal: an overview based on impedance spectroscopy. J Phys Chem Solids 62:1999–2006CrossRefGoogle Scholar
  19. 19.
    Andrew KJ (1999) Dielectric relaxation in solids. J Phys D Appl Phys 32:R57CrossRefGoogle Scholar
  20. 20.
    Shulman HS, Testorf M, Damjanovic D, Setter N (1996) Electrical conductivity, and piezoelectric properties of bismuth titanate. J Am Ceram Soc 79:3124–3128CrossRefGoogle Scholar
  21. 21.
    Wu Y, Cao G (2000) Ferroelectric and dielectric properties of strontium bismuth niobate vanadates. J Mater Res 15:1583–1590CrossRefGoogle Scholar
  22. 22.
    Park BH, Hyun SJ, Bu SD, Noh TW, Lee J, Kim H-D, Kim TH, Jo W (1999) Differences in nature of defects between SrBi2Ta2O9 and Bi4Ti3O12. Appl Phys Lett 74:1907–1909CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2016

Authors and Affiliations

  • Supratim Mitra
    • 1
    • 3
  • Pankaj K. Patro
    • 2
  • Ajit R. Kulkarni
    • 1
  1. 1.Department of Metallurgical Engineering and Materials ScienceIndian Institute of Technology BombayMumbaiIndia
  2. 2.Powder Metallurgy DivisionMaterials Group BARCMumbaiIndia
  3. 3.NIIT UniversityNeemranaIndia

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