Influence of Mn on Electronic Performance of SnO2-Sb2O3 Based Varistor

SnO2-Sb2O3 based varistor ceramic materials doped with TiO2, Co3O4, Cr2O3, Ni2O3, and MnO were fabricated by conventional electronic ceramic process. The influence of MnO on the densification, low current area V-I nonlinear characteristic and withstanding surge current capability were investigated. It was found that a small amount of MnO addition can improve nonlinear and surge cur-rent test performances. When the content of MnO is more than 0.06%, the nonlinear coefficient decreases and the leakage current increases. For better distribution of Mn in the material, Mn(NO3)(2) aqueous solution is preferable to MnCO3 as the precursor of MnO. The obtained SnO2-Sb2O3 based varistor samples with 0.06 similar to 0.1mol% Mn(NO3)(2) show promising varistor behavior with nonlinear coefficient (alpha) of 30 similar to 50, breakdown electric filed of about 330 similar to 350 V/mm, and withstanding peak current of 1.5 kA/cm(2) of 8/20 mu s wave surge.