Microstructure and Current–Voltage Characteristics of Multicomponent Vanadium-Doped Zinc Oxide Varistors

The effects of the oxide additives MnO₂, Co₃O₄, and Sb₂O₃, commonly incorporated in commercial Bi₂O₃-doped ZnO varistors, on the current–voltage characteristics and microstructure of 0.25 mol% V₂O₅-doped ZnO varistors have been studied. MnO₂ is the most significant additive in terms of its effects on varistor performance. Varistor performance can also be improved by increasing the V₂O₅ content to 0.5 mol% in a ZnO ceramic containing 1 mol% MnO₂. Further increases in the V₂O₅ content of 1 mol% MnO₂-doped material cause a deterioration in varistor behavior. The microstructure of the samples consists mainly of ZnO grains with zinc vanadates as the minority secondary phases. Additional spinel phase is formed when Sb₂O₃ is incorporated.     

热处理对ZnO变阻器电学性能影响的研究

采用高能球磨的方法制备了ZnO和添加物(MnO,Sb2O3,CoO,Cr2O3,Bi2O3)的前驱超细粉体,采用固相反应烧结技术在1 140℃进行2 h烧结制备出ZnO陶瓷变阻器。用SEM,XRD研究了不同退火温度对ZnO压敏陶瓷的显微形貌、相结构,伏安非线性特性和微观电性能的影响。从阻抗分析,激活能和介电损耗与频谱关系分析证明了600～800℃热处理时晶界由于β-Bi2O3向γ-Bi2O3的相变引起的体积膨胀而变宽,导致晶界电子陷阱浓度降低,从而使得势垒高度下降,漏电流增加。     

稀土掺杂氧化锌压敏瓷的研究进展

综述了近年来稀土掺杂氧化锌压敏瓷中的研究进展。掺杂稀土氧化物可明显的减小ZnO晶粒尺寸,使晶粒尺寸分布均匀;其中掺杂Y2O3可使ZnO-Bi2O3系压敏瓷晶粒尺寸由11.3μm降到5.4μm,掺杂Er2O3使晶粒尺寸由1.60μm减小到1.06μm。显著提高了ZnO压敏瓷的电位梯度、降低了漏电流。其中在ZnO-Bi2O3系压敏瓷中掺杂Y2O3,可获得电位梯度约为270 V/mm、漏电流为3μA、压比为1.66的电阻片,在ZnO-PrA6O11系压敏瓷中掺杂Er2O3,电位梯度可提高到416.3 V/mm,漏电流从28.2μA降低到9.8μA。     

Size Effect on Properties of Varistors Made From Zinc Oxide Nanoparticles Through Low Temperature Spark Plasma Sintering

Conditions for the elaboration of nanostructured varistors by spark plasma sintering (SPS) are investigated, using 8‐nm zinc oxide nanoparticles synthesized following an organometallic approach. A binary system constituted of zinc oxide and bismuth oxide nanoparticles is used for this purpose. It is synthesized at room temperature in an organic solution through the hydrolysis of dicyclohexylzinc and bismuth acetate precursors. Sintering of this material is performed by SPS at various temperatures and dwell times. The determination of the microstructure and the chemical composition of the as‐prepared ceramics are based on scanning electron microscopy and X‐ray diffraction analysis. The nonlinear electrical characteristics are evidenced by current–voltage measurements. The breakdown voltage of these nanostructured varistors strongly depends on grain sizes. The results show that nanostructured varistors are obtained by SPS at sintering temperatures ranging from 550 to 600 °C.     

多层片式压敏电阻器

介绍了多层片式压敏电阻器的结构原理、特征、应用，应用试验结果证实，所研制的电阻 具有响应速度快，限制电压低，温度特性好，通流能力大等优点。故将在信息及家电行业获得广泛应用。     

片式叠层压敏电阻器及其应用

用流延工艺把电极层和半导体陶瓷交错排布，经烧结而成的片式叠层压敏电阻器，其结构类似多层陶瓷电容器。通过与氧化锌压敏电阻器及其他压敏电阻器比较表明，片式叠层压敏电阻器具有优良的性能。并论述这类压敏电阻器在ＩＣ保护、ＣＭＯＳ器件保护、汽车电路系统保护等方面的应用。     

叠层片式ZnO压敏电阻的微观结构研究

通过光学显微镜、扫描电镜观察及能谱分析等方法，分析研究了叠层片式压敏电阻器（MLV,mutilayer varistor）的微观结构．实验结果表明，在半成品叠层片式压敏电阻器的微观结构中ZnO晶粒较小且不均匀，结构较疏松，强度差．而成品由于进行了低温液相烧结，其微观结构则为较规则的ZnO晶粒，晶粒变大尺寸较为均匀，致密度明显提高．由于在陶瓷叠片上内电极浆料分布不均匀或电极印刷的原因，经过烧结后个别地方可能出现内电极层的缺损，以至观察到的内电极是断续的。同时观察到空洞可影响到内电极扣外电极的连接，以及电极变形等现象。这些缺陷结构的形成与叠层片式压敏电阻器的制作工艺有关．     

Voltage-Current Characteristics of a Simple Zinc Oxide Varistor Containing Magnesia

This paper examines the effect of MgO addition on the structural and electrical characteristics of a ZnO varistor composition with few dopants. MgO acts as a grain-growth inhibitor. The electrical performances of the obtained varistors are improved.     

从INMR全球会议看避雷器的发展趋势

结合2011年INMR全球会议的相关论文对避雷器的现状和研究进展进行了综述.介绍了线路避雷器的技术进展、避雷器的监测、避雷器的应用开发与IEC60099-4和IEC60099-5两个标准的修订情况.新发布的IEC60099-8明确了外串间隙线路避雷器(EGLA)的试验项目和试验方法,促进了其应用.避雷器将用在绿色能源发...     

基于PSPICE仿真与试验的压敏电阻并联性能

金属氧化物压敏电阻(MOV)是防护电气电子设备因受雷电闪击及其他瞬态电磁干扰造成传导过电压危害的有效器件,它的性能直接影响安全保护效果。国内外常将几片MOV并联在一起使用,这样不仅可降低残压,还可起到分流延长MOV寿命的作用。利用PSPICE仿真工具,对不同并联片数MOV进行大量仿真模拟,绘制出残压、通流的变化关系,得...