Sintering effect on electrical properties and pulse aging behavior of（V₂O₅-Mn₃O₄-Er₂O₃ ）-doped zinc oxide varistor ceramics

Choon-W.Nahm

Semiconductor Ceramics Laboratory, Department of Electrical Engineering, Dongeui University

摘 要：The effect of sintering temperature on microstructure, electrical properties, and pulse aging behavior of（V2 O5-Mn3 O4-Er2 O3）-doped zinc oxide varistor ceramics was systematically studied. When the sintering temperature increased, the average grain size increased from 6.1 to 8.7 m and the sintered density decreased from 5.52 to 5.43 g/cm3. The breakdown field decreased from 3856 to 922 V/cm with an increase in the sintering temperature up to 900 C, whereas a further increase to 2352 V/cm at 925 C. The nonlinear coefficient increased pronouncedly from 4.6 to 30.0 with an increase in the sintering temperature. The varistor ceramics sintered at 850 C exhibited the best clamping characteristics, with the clamp voltage ratio of the range of 2.22–2.88 for pulse current of 1–25 A. The varistor ceramics sintered at 925 C exhibited the strongest stability, with %ΔE 1 mA/cm2=–8.8% after applying the multi-pulse current of 25 A.

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