Nonlinear Electrical Properties of (Sc, Ta) Doped TiO2 Varistor Ceramics


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The nonlinear electrical properties of TiO2-based varistor doped with 0.25mol% Ta2O5 and different contents of Sc2O3 were investigated. It was found that the TiO2 varistor ceramic doped with 0.10mol% Sc2O3 exhibited an optimal nonlinear coefficient of 7.8, a breakdown electrical field of 16.0V/mm, and relative dielectric constant of 1.27 × 105 (measured at 1 kHz). In order to analyze the effect of Sc2O3 on TiO2 varistors, studies were made on the capacitance versus voltage characteristics. A Schottky-type barrier, which is assumed as the origin of varistor behavior, was inferred from the C-V measurement. The barrier height and donor concentration were obtained as 0.41eV and 1.21 × 1026cm-3, respectively, for sample doped with 0.10mol% Sc2O3. Analogized to the ZnO varistors, the formation mechanism of Schottky-type barrier was discussed in this paper by the theory of defect in crystal lattice.



Key Engineering Materials (Volumes 280-283)

Edited by:

Wei Pan, Jianghong Gong, Chang-Chun Ge and Jing-Feng Li




W. B. Su et al., "Nonlinear Electrical Properties of (Sc, Ta) Doped TiO2 Varistor Ceramics", Key Engineering Materials, Vols. 280-283, pp. 289-292, 2005

Online since:

February 2007




[1] T.K. Gupta: J. Am. Ceram. Soc. Vol. 73 (1990), p.1817.

[2] D.R. Clarke: J. Am. Ceram. Soc. Vol. 82 (1999), p.485.

[3] S.L. Yang and J. M. Wu: J. Am. Ceram. Soc. Vol. 76 (1993), p.145.

[4] J.M. Wu and C.H. Lai: J. Am. Ceram. Soc. Vol. 74 (1991), p.3112.

[5] J.F. Wang, H.C. Chen, X.H. Zhang and D.J. Zhang: Chin. Phys. Lett. Vol. 17 (2000), p.530.

[6] W.B. Su, J. F. Wang, H.C. Chen, W.X. Wang and G.Z. Zang: J. Appl. Phys. Vol. 92 (2002), p.4779.

[7] K. Mukae, K. Tsuda and I. Nagasawa: J. Appl. Phys. Vol. 50 (1979), p.4475.

[8] P. R Bueno, M.M. Oliveira, W.K. Bacelar, E.R. Leite and E. Longo: J. Appl. Phys. Vol. 91 (2002), p.6007. Fig. 6. Schottky barrier model for TiO2 varistor doped with Sc2O3.

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