ZnO バリスタ　ニ　オケル　コタイ　カガクテキ　カンテン　カラノ　コウサツ

Abstract

ZnO varistor - ceramic non-linear resistor mainly composed of zinc oxide is used for arrestor and SPD (Surge Protective Device), which prevent electrical alliances from being damaged by lightning surge. Technically, the nonlinear index of ZnO varistor is most important performance barometer because the larger non-linear index brings about the lower residual voltage on electrical alliances under lightning surge. One of the typical methods to increase non-linear index is small-quantity Aluminum addition. The addition is said to be a function of replacing zinc atom with Aluminum atom on zinc site. Aluminum atom is said to provide donor electron, decrease resistivity inside zinc oxide poly-crystal, and bring about lower residual voltage. But we re-investigated the role of Aluminum element, and created the new phenomena from the perspective of solidstate chemistry. Consequently, we find new mechanism of Aluminum additive to thin boundary layers between ZnO particles and increase effective cross section area, and lower electrical resistivity by inhibiting particle growth during sintering