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Electrical Properties of ZnO Varistors with Variation of Co3O4

Co3O4 첨가량 변화에 따른 ZnO Varistor의 전기적 특성

  • 조현무 (서남대학교 전기전자공학부) ;
  • 이성갑 (서남대학교 전기전자공학부)
  • Published : 2004.11.01

Abstract

ZnO varistor ceramics which were fabricated with variation of added of 0.5~1.0 mol% Co$_3$O$_4$, were sintered at 1150 $^{\circ}C$. In the specimen added 0.7 mol% Co$_3$O$_4$, sintered density was 6.03 g/㎤ and electrical properties were superior to any other compositions. The nonlinear coefficient a and clamping voltage ratio were 83 and 1.35, respectively. But, endurance surge current in the specimen added 0.5 mol% Co$_3$O$_4$ was 7000 A/$\textrm{cm}^2$, and deviation of varistor voltage was Δ-3.23 %. As P.C.T and T.C.T environmental test were succeed in all specimens, and deviation of varistor voltage in the specimen added 0.6 mol% Co$_3$O$_4$ was Δ-0.81 %. All specimens showed good leakage current property on the High Temperature Continuous Load Test(HTCLT) for 1000 hr at 85 $^{\circ}C$ and variation rate of the varistor voltage below Δ-2.0 %.

Keywords

References

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