| 摘要 |
PURPOSE:To realize a varister of very high stability with excellent nonlinearity but without any deterioration with time, by containing a predetermined amount of bismuth and antimonium with relations between lead and bismuth and between tantalum and bismuth in an admixture respectively being in a predetermined range. CONSTITUTION:Consisting mainly of zinc oxide and containing at least lead, bismuth, tantalum and antimonium as an admixture, a sintered material is formed containing 0.05-1.0 mol% of bismuth expressed in terms of Bi2O3 and 0.05-3.0 mol% of antimonium expressed in terms of Sb2O3 with relations between the lead and the bismuth and between the tantalum and the bismuth respectively being in ranges of Pb/Bi=0.05-0.5 and Ta/Bi=0.2-2.0 in said admixture, and at a grain boundary segregation part of crystal grains in the sintered material mainly composed of zinc oxide, constitutes 50% or more of all the bismuth in the said sintered material so as to be a pyrochlore type compound. |
