Modeling of electrical transport in Zinc Oxide varistors

[摘要] The electrical transport in zinc oxide (ZnO) varistors is analyzed usingmicrostructural material modeling. The fully three dimensional currentdistribution is computed by means of a nonlinear equivalent circuit modelrepresenting the assembly of current carrying grains and grain boundaries ofthe material. The investigation focuses on the phenomenon of currentfilamentation due to inhomogeneities of the varistor microstructure.Numerical results highlight the importance of 3-D percolation effectsin the modeling of varistor currents as well as that of the grain bulkresistivity which so far has been neglected in previous studies.

[学科分类] 电子、光学、磁材料