Effect of La₂O₃ on the Microstructure and Electrical Properties of (Ti,Sn)O₂ Varistor Ceramics

Abstract:

(Ti,Sn)O2 varistors doped with different amount of La2O3 were obtained by ceramic sintering processing at 1250 . The effect of La2O3 on the microstructure and nonlinear electrical behavior of the (Ti,Sn)O2 ceramics were investigated. The ceramics have nonlinear coefficients of α=6.2–8.5. Experimental evidence shows that small quantities of La2O3 improve the nonlinear properties of the samples significantly. It was found that an optimal doping composition of 1.0mol% La2O3 leads to a low breakdown voltage of 18.1V/mm, a high nonlinear coefficient of 8.5, which is consistent with the highest and narrowest grain boundary barriers of the ceramics.In view of these electrical characteristics, the (Ti,Sn)O2 varistors with 1.0mol% La2O3 ceramic is a viable candidate for low voltage varistor devices. The characteristics of the ceramics can be explained by the effect of the substitution of La3+ for Ti4+ or Sn4+.

• Periodical: Advanced Materials Research (Volumes 152-153)
• Pages: 1391-1394
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.152-153.1391
• Online since: October 2010
• Authors: Mao Hua Wang, Gang Li, Chao Yao
• Keywords: Electrical Properties, La₂O₃, Microstructure, Varistor

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