Dependence of Properties of High Voltage Zinc Oxide Varistor from Antimony and Nickel Oxides

Resumo

Studies were carried out to reduce the leakage current of high-voltage ZnO varistor ceramics by varying Sb₂O₃ and NiO content in a ZnO-Bi₂O₃-Sb₂O₃-Al₂O₃-Co₃O₄-NiO. It was found that the ceramic composition (wt %): ZnO 80, Bi₂O₃ 5.83, Sb₂O₃ 2.62, A1₂O₃ 4.66, Co₂O₃ 3.80, NiO 3.09, has a minimum leakage current density I_out ≤ 0.1 μA cm^-2, breakdown voltage U_b = 4.1kV mm^-1, nonlinearity coefficient α = 65. The resulting ceramics are promising for the production of varistors with high stability of performance.