Author/Authors :
F.M. Filho، نويسنده , , A.Z. Simoes، نويسنده , , A. Ries، نويسنده , , I.P. Silva، نويسنده , , L. Perazolli، نويسنده , , E. Longo، نويسنده , , J.A. Varela، نويسنده ,
Abstract :
SnO2-based varistors doped with 0.5% cobalt, 0.5% zinc and various tantalum amounts were prepared by the solid-state route. Experimental evidence shows that small quantities of Ta2O5 improve the nonlinear properties of the samples significantly. It was found that samples doped with 0.05 mol% Ta2O5 exhibit the highest density (98.5%), the lowest electric breakdown field (Eb=1050 V/cm) and the highest coefficient of nonlinearity (α=11.5). The effect of Ta2O5 dopant could be explained by the substitution of Ta5+ by Sn4+.
