V_2O_5在ZnO-V_2O_5压敏陶瓷低温烧结中的双重作用  

Dual Effects of V_2O_5 in ZnO-V_2O_5 Varistor Ceramics During Low Temperature Sintering

作　　者：周健[1] 徐国跃[1] 曹敏[1] 侯清建[1] 

机构地区：[1]南京航空航天大学材料科学与技术学院,江苏南京210016

出　　处：《电瓷避雷器》2005年第5期39-42,共4页Insulators and Surge Arresters

基　　金：国防基础科研项目(J1300A002)。

摘　　要：制备了V2O5含量为0.25%(摩尔分数)的双组元ZnO压敏陶瓷,采用电子自旋共振谱(ESR)研究了V2O5中V离子的价态变化。结果表明,V离子是一种受主杂质,热处理后,其价态产生了变化,尤其是在655℃热处理时价态变化程度最明显,与V2O5的差热分析(DTA)结果相吻合。差热分析显示,V2O5在655℃存在一相变吸热峰,此时样品的低价态V离子的ESR信号最强。V-I非线性测试结果也显示,低价态V离子ESR信号越强,宏观非线性系数越大。V2O5同时起着液相添加剂的作用,使ZnO-V2O5压敏陶瓷在900℃致密化。The valence of V ion was studied on prepared ZNO-0.25% V2Os binary varistor ceramic samples,by the electron spin resonance （ESR）. Results show that V^5＋ is an acceptor impurity whose valence changes after heat treatment especially at 655℃. The phenomenon is consistent with the result of the differential thermal analysis （DTA）. Result of DTA indicates that V2O5 has a phase transformation absorption peak at 655℃ while the signal of ESR of low valence of V ion is the strongest. The results of V-I nonlinear testing indicates that the microscopical nonlinearity coefficient improves as long as the ESR signal of low valence V ion becomes strong. Meanwhile, V2O5 serves as a liquid phase additive, due to its low melting point making ZnO-V2O5 varistor ceramic densifing at 900℃.

关 键 词：ZnO-V2O5压敏陶瓷 V离子的价态 V-I非线性 

分 类 号：TM28[一般工业技术—材料科学与工程]