Influence of Nb addition on microstructure, electrical, dielectric properties, and aging behavior of MnCoDy modified Zn–V-based varistors

  • Choon-Woo NahmEmail author


The microstructure, electrical properties, dielectric characteristics, and DC accelerated aging behavior of the MnCoDy modified Zn–V-based varistors were investigated for Nb amount of 0.0–0.25 mol% by sintering at 900 °C. The microstructure of the MnCoDy modified Zn–V-based varistors consisted of ZnO grain as a main phase and Zn3(VO4)2, ZnV2O4, and DyVO4 as the secondary phases. The Nb addition led to the increase of grain size, whereas it does not have an effect on the sintered density. The nonlinear coefficient improved with the increase of Nb amount up to 0.1 mol%, whereas the further Nb additions impaired it. A maximum of the nonlinear coefficient (35) was obtained at 0.1 mol% Nb. The Nb acted as a donor less than 0.1 mol% and an acceptor more than 0.25 mol%. The best stability of system against DC accelerated aging stress was obtained at 0.1 mol% Nb, in which %ΔE1 mA = −0.24%, %Δα = −15.4%, %Δ ε′APP = −1.4%, and %Δ tanδ = +12.5% for stress state of 0.85 E1 mA/85 °C/24 h.


Barrier Height Schottky Barrier Leakage Current Density Nonlinear Coefficient Sintered Density 
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.


  1. 1.
    L.M. Levinson, H.R. Philipp, Am. Ceram. Soc. Bull. 65, 639 (1986)Google Scholar
  2. 2.
    T.K. Gupta, J. Am. Ceram. Soc. 73, 1817 (1990)CrossRefGoogle Scholar
  3. 3.
    C.-W. Nahm, Mater. Lett. 47, 182 (2001)CrossRefGoogle Scholar
  4. 4.
    C.-W. Nahm, J. Mater. Sci. Lett. 21, 201 (2002)CrossRefGoogle Scholar
  5. 5.
    J.-K. Tsai, T.-B. Wu, J. Appl. Phys. 76, 4817 (1994)CrossRefADSGoogle Scholar
  6. 6.
    J.-K. Tsai, T.-B. Wu, Mater. Lett. 26, 199 (1996)CrossRefGoogle Scholar
  7. 7.
    C.T. Kuo, C.S. Chen, I.-N. Lin, J. Am. Ceram. Soc. 81, 2942 (1998)CrossRefGoogle Scholar
  8. 8.
    H.-H. Hng, K.M. Knowles, J. Eur. Ceram. Soc. 19, 721 (1999)CrossRefGoogle Scholar
  9. 9.
    H.-H. Hng, L. Halim, Mater. Lett. 57, 1411 (2003)CrossRefGoogle Scholar
  10. 10.
    H.-H. Hng, P.L. Chan, Ceram. Int. 30, 1647 (2004)CrossRefGoogle Scholar
  11. 11.
    C.-W. Nahm, J. Mater. Sci. 42, 8370 (2007)CrossRefADSGoogle Scholar
  12. 12.
    C.-W. Nahm, Solid State Commun. 143, 453 (2007)CrossRefADSGoogle Scholar
  13. 13.
    C.-W. Nahm, Mater. Sci. Eng. B 150, 32 (2008)CrossRefGoogle Scholar
  14. 14.
    J.C. Wurst, J.A. Nelson, J. Am. Ceram. Soc. 55, 109 (1972)CrossRefGoogle Scholar
  15. 15.
    M. Mukae, K. Tsuda, I. Nagasawa, J. Appl. Phys. 50, 4475 (1979)CrossRefADSGoogle Scholar
  16. 16.
    J. Fan, R. Freer, J. Am. Ceram. Soc. 77, 2663 (1994)CrossRefGoogle Scholar
  17. 17.
    G.D. Mahan, J. Appl. Phys. 75, 3825 (1983)CrossRefADSGoogle Scholar
  18. 18.
    M.F. Yan, A.H. Heuer, in Additives and Interfaces in Electronic Ceramics (American Ceramic Society, Columbus, OH, 1983), p. 71Google Scholar

Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  1. 1.Semiconductor Ceramics Lab., Department of Electrical EngineeringDongeui UniversityBusanKorea

Personalised recommendations