Progressive degradation of high voltage ZnO commercial varistors upon Fe2O3 doping

摘要: Abstract In the complex multicomponent formulation of standard commercial varistors used in high tension devices, those based ZnO–Bi 2 O 3 –Sb (ZBS) ternary system, presence iron is ordinarily prevented any its plausible sources: dopant, impurity and/or unwanted contamination. Otherwise material undergoes a systematic degradation electrical performance which rapidly disallows it for practical uses. order to understand origin such phenomena, we have deliberately doped ZBS varistor composition with different amounts Fe . The research here presented evidences that prime reason ruination progressive incorporation inside spinel secondary grains, eventually leads formation highly conductive skeleton phases an unbearable level leakage currents below breakdown voltage.