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Journal of Advanced Ceramics

Keywords

ceramics, electrical properties, microstructure, varistor, Mn3O4 doped ZnO–V2O5 varistor

Abstract

The effect of Mn3O4 addition on microhardness, microstructure and electrical properties of vanadium oxide doped zinc oxide varistor ceramics is systematically investigated. The Vicker's microhardness HV has decreased with increasing the amount of Mn3O4. Also, the average grain size has decreased from 27.51 μm to 19.55 μm with increasing the amount of Mn3O4 up to 0.50 mol%, whereas an increase in Mn3O4 up to 0.75 mol% has caused the average grain size to increase and then it decreases with increasing Mn3O4 from 0.75 mol% to 1.00 mol%. The sintered density has decreased from 5.38 g/cm3 to 5.31 g/cm3 with increasing the amount of Mn3O4. The varistor ceramic modified with 0.50 mol% Mn3O4 has exhibited excellent nonlinear properties, with 16.29 for the nonlinear coefficient and 441.9 μA/cm2 for the leakage current density. Furthermore, the sample doped with 0.50 mol% Mn3O4 has been found to possess donor density as 0.77×1018 cm-3 and 0.916 eV barrier height.

Publisher

Tsinghua University Press

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