Effect of Fe sub(2)O sub(3) doping on the electrical properties of a SnO sub(2) based varistor

• Published in: Journal of materials science Vol. 37; no. 12; pp. 2407 - 2411
• Main Authors: Antunes, A C, Antunes, S R M, Zara, A J, Pianaro, S A, Longo, E, Varela, J A
• Format: Journal Article
• Language: English
• Published: 15.06.2002
• ISSN: 0022-2461

The effect of Fe sub(2)O sub(3) addition on the densification and electrical properties of the (0.9895 - x) SnO sub(2) + 0.01CoO + 0.005Nb sub(2)O sub(5) + xFe sub(2)O sub(3) system, where x= 0.005 or 0.01, was considered in this study. The samples were sintered at 1300 degree C for 2 h. Microstructure analysis by scanning electron microscopy showed that the effect of Fe sub(2)O sub(3) addition is to decrease the SnO sub(2) grain size. J x E curves indicated that the system exhibit a varistor behavior and the effect of Fe sub(2)O sub(3) is to increase both, the non-linear coefficient ( alpha ) and the breakdown voltage (E sub(r)). Considering the Schottky thermionic emission model the potential height and width were estimated. Small amount addition of Fe sub(2)O sub(3) to the basic system increases both the potential barrier height and width. copyright 2002 Kluwer Academic Publishers.