Effect of Heat Treatment on the Nonlinear Exponents in ZnO Varistors

열처리에 따른 ZnO 바리스터의 비직선 계수의 영향

  • 안충선 (경상대학교 무기재료공학과) ;
  • 심영재 (경상대학교 무기재료공학과) ;
  • 조병두 (경상대학교 무기재료공학과)
  • Published : 1992.02.01


Nonlinear exponents and electron trap density variations were observered in ZnO-Bi2O3-MnO2 ternary ZnO varistors as a function of heat treatment temperature. Three kinds of ZnO varistor compositions were selected; i.e. 99.0 ZnO-0.5 Bi2O3-0.5 MnO2, 98.5 ZnO-1.0 Bi2O3-0.5 MnO2, and 98.0 ZnO-1.5 Bi2O3-0.5 MnO2 in mol%. Sintering was done at 1150$^{\circ}C$ for three hours, and heat treatments were done at 500$^{\circ}C$, 700$^{\circ}C$, and 900$^{\circ}C$. When heat treated at 500$^{\circ}C$, nonlinear exponents were increased regardless of the Bi2O3 amount. Increasing heat treatment temperature above 500$^{\circ}C$ resulted in lowering nonlinear exponents. Nonlinear exponents seem to be related to the 0.17 and 0.33 eV electron traps which are possibly of intrinsic origin.



  1. Am Ceram. Soc. Bull. v.65 no.4 Zinc Oxide Varistors A Review L.M. Levinson;H.R. Philipp
  2. J. Appl. Phys. v.48 no.4 Low-temperature Electrical studies on Metal-oxide Varistors-A Clue to Conduction Mechanisms H.R. Philipp;L.M. Levinson
  3. Ph. D Thesis Electron Traps in Zinc Oxide Varistors Youngjae Shim
  4. J Appl Phys. v.63 no.11 The Depp Level Transient Spectroscopy Studies of a ZnO Varistor as a Function of Annealing A. Rohatai;S.K. Pang;T.K. Gupta;W.D. Straub
  5. J Appl. Phys. v.66 no.11 Effects of Dopants on the Deep Bulk Levels in the ZnO-Bi₂O₃-MnO₂ System Youngjae Shim;James F. Condaro
  6. J. Apply. Phys. v.60 no.12 Bulk Electron Traps in ZnO Varnstors J.F. Cordaro;Y. Shim
  7. Phys. Rev. B v.33 no.6 Carrier Transport Through Grain Boundaries in Semiconductors G. Blatter;F. Greuter
  8. Jpn. J. Appl. Phys. v.10 no.6 Nonhmic Properties of ZnO Ceramics Matsuoka
  9. J. Phys. Chem. Solids v.11 Infrared Relfectivity of Zinc Oxides R.J. Collins;Dd A. Klcinman
  10. J Appl Phys v.66 no.11 Origin of the Pulse Response Characteristics of Zinc Oxide Varistors F.A. Modine;R.B. Wheeler;Y. Shin;J.F Cordaro