Grain Size Effects of SnO₂ Varistor Induced by Doping Pr

Abstract:

The effects of Pr on the microstructure and nonlinear electrical properties of the (Co,Ta)-doped SnO2 varistors were investigated. It was found by characterizing the samples sintered at 1350 oC that the breakdown voltage increases significantly from 500v/mm to 1200v/mm, and the relative permittivity decreased rapidly from 2525 to 1199 with increasing Pr6O11 concentration from 0 to 1.20 mol%. The analysis of samples’ microscopic structure showed that the grain size of SnO2 rapidly decreases from 5.1 to 3.7 µm with increasing Pr6O11 concentration from 0 to 1.20mol% .The significant decrease of SnO2 grain size is the main reason for raising breakdown voltage and reducing permittivity.

• Periodical: Key Engineering Materials (Volumes 280-283)
• Pages: 275-278
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.280-283.275
• Online since: February 2007
• Authors: Cheng Ju Zhang, Jin Feng Wang, Wen Bin Su, Guo Zhong Zang, Hong Cun Chen
• Keywords: Barrier, Electrical Nonlinearity, Permittivity, TiN Dioxide

References

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

[2] S.A. Pianaro, P.R. Bueno, E. Longo and J.A. Varela: J. Mater. Sci. Lett. Vol. 14 (1995), p.692.

[3] C.P. Li and J.F. Wang: Chin. Phys. Lett. Vol. 18 (2001), p.674.

[4] C.P. Li and J.F. Wang: Ceram. Int. Vol. 28 (2002), p.521.

[5] W.X. Wang and J.F. Wang: J. Physica D. Vol. 36 (2003), p.1040.

[6] J.F. Wang, Y.J. Wang and W.B. Su: Mater. Sci. Eng. B. Vol. 96 (2002), p.8.

[7] C.P. Li, J.F. Wang and W.B. Su: J. Physica B, Vol. 307 (2001), p.1.

[8] C.P. Li, J.F. Wang and W.B. Su: J. Eur. Phys. J AP. Vol. 16 (2001), p.3.

[9] S.A. Pianaro, P.R. Bueno and J.A. Varela: J. Mater. Sci. Lett. Vol. 14 (1995), p.692.

[10] P.R. Bueno, S.A. Pianaro, et al.: J. Appl. Phys. Vol. 84 (1998), p.3700.

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