用热刺激电流（TSC）和电声脉冲法研究了ZnO压敏陶瓷与绝缘材料间界面电荷分布。发现绝缘材料显著地影响界面电荷性质和密度，压敏陶瓷与聚酯型聚氨酯界面存在大量电荷，而压敏陶瓷与聚酯改性有机硅界面没有电荷。压敏陶瓷与绝缘材料间的界面电荷降低压敏电阻片的沿面脉冲闪络电压。

发现具有相变的Bi203系和不具有相变的Pr2O3系ZnO压敏陶瓷能从400℃附近起产生热释电电流，这是在高温热过程中ZnO压敏陶瓷内有电荷迁移的直接证据。研究了升温速度和热循环次数对Bi2O3系和Pr2O3系ZnO压敏陶瓷热释电规律的影响。结果表明，在一定升温速度范围内高温热释电电流，I-T曲线与升温速度无关；热历史对Pr2O3系ZnO压敏陶瓷的，I-T曲线几乎没有影响，但对Bi2O3系的，I-T曲线的影响显著、规律性强。

本文采用单元掺杂与多元掺杂的方法。系统研究了几种过渡金属氧化物添加荆在控倒ZnO压敏陶瓷非线性方面的作用，并根据金属阳离子外亮层电子结构稳定性和缺陷化学反应进行了分析，认为阳离子具有不饱和外层电子结构且半径与Zn2+离子相近的过渡金属氧化物能改善ZnO压敏陶瓷非线性。

研究了在2ms脉冲电流冲击下烧银电极的ZnO陶瓷线性电阻片的破坏模式、8/20μs 标准脉冲电流冲击对表观电阻的影响规律、烧银电极的烧结温度和保温时间对表观电阻等的影响。测量了表观电阻与试样厚度的关系，进行了扫描电镜的能谱元素分析。研究结果表明，烧银电极与ZnO线性电阻陶瓷体间的电接触是非欧姆接触，其非线性指数为1.68。该非欧姆接触电阻是在烧银过程中银浆中的Pb2+离子沿晶界向瓷体内部扩散的结果，是ZnO陶瓷线性电阻片非线性指数α增大，表观电阻在8/20μs 脉冲电流冲击后下降等现象的原因。

本文研究了不同工艺条件制备的znO非欧姆陶瓷材料的介电和损耗特性，根据介电频谱和低温温谱，认为音频损耗机理是载流子跳跃传输，低温-138℃和-87.5℃处的损耗机制是热离子极化。实验发现并理论推导了znO非欧姆陶瓷元件的阻性电流正比于其电容和压敏电压的乘积，这一关系可作为ZnO元件的质量控制手段。

The effect of the sample thickness d on the residual voltage ratio Kr indicates the existence of the dimensional effect in the commercial ZnO varistors. The empirical relations derived are based on experimental findings for Kr and breakdown electric field strength E1 mA cm-2 and the microstructural parameter average grain size μ. It is observed that Kr decreases with increasing E1 mA cm-2, while it increases with increasing μ. An integrated hybrid parameter σ2μ, obtained as the product of average grain size l and grain size variance σ2, is found to be a representative relation between electrical properties and microstructure of the ZnO varistors. A microstructural model is used for computer simulation that also verified the dimensional effect in these varistors. The simulated results are consistent with the experimental results.

The processing-microstructure-property relations have been studied in order to understand the role of the addition of CeO2 (up to 0.9 mole%) in the ZnO-Bi2O3 based varistor recipe. The microstructural investigation suggests that CeO2 is segregated at the corners of the ZnO grains in addition to the existence of the Zn7Sb2O12 spinel phase. However, the α-spinel phase was observed instead of the β-spinel phase that is usually found in most commercial and laboratory ZnO-Bi2O3 based varistors. The α-spinel phase is more stable than the β-spinel phase and does not transform to the pyrochlore phase during the cooling process. The most significant effect of the CeO2 particles is the ZnO grain refinement owing to the pinning effect of the grain growth. The average grain size decreases from 7.8 to 5.7μm when compared to the 0.9 mole% CeO2-added sample against the CeO2-free sample. This grain refinement results in a significantly enhanced breakdown field when compared to the CeO2-free sample. The coefficient of nonlinearity of the current–voltage (I-V) characteristics is found to be nearly identical for the CeO2 added varistor materials. However, when a slower cooling cycle (1℃ min−1 instead of 4℃ min−1) is used in the sintering process, these varistor materials exhibited a high nonlinear coefficient (α=29±5) as extracted from the I-V behaviour.

The relationship between the breakdown electric field EB (electric field corresponding to the current density 1mAcm−2) and thickness d for three types of Zinc oxide (ZnO) varistors were investigated. The geometric dimensional effect, observed in these varistors, is referred to as the responsible parameter for the change in EB with the variation in the thickness of the varistor samples. The variation in the diameter of the ZnO grains and the corresponding aspect ratio due to the irregularity of each ZnO grain shape are used to characterize the microstructural heterogeneity of the resulting ZnO grain size distribution. The distribution of the ZnO grain size is statistically analysed, and thereby a model of the microstructure is proposed. The thickness dependence of the breakdown field, EB, obtained via computer simulation shows a similar dimensional effect to the one observed experimentally. It was found that the critical thickness, dc, incr eases linearly with the dispersive ratio of the ZnO grain length, and the corresponding slope (b2) in the large thickness domain is directly proportional to the aspect ratio of the ZnO grains.

The electrical property and microstructure of SrTiO, capacitor-varistor ceramics sintered in different atmospheres were investigated in the present study. The electrical experimental results show that samples sintered in strong reducing atmosphere of 25%N2+75%H2 and heat-treated in air have a low-resistive core with a high-resistive surface layer around it which is named surface effect. The XPS results reveal that surface effect results from the diffusion process of oxygen during heat-treatment.

The intotfacial sDace charge distribution between ZnO varistor ceramics mad different collar coating matedals was investigated using the Pulsed Electroacoustic Method (PEA) and Thornlal Stimulated Current (TSC) methods. The experimental results show that a large amount of sDace charge accumulates at the interface between ZnO varistor ceramics and polyester polyurethane. while there is less spacc charge presents attheinterface betwean ZnO varistor ceramics and polyester modified silicone. The PEA results show that the inlroduction ofinorganic glass between ZnO varistor ceramics and organic coating materials can greatly reduce the amoullt of space charge. The results from the surface flashover measurement,which was based on 4/10 Bs stcep irepulse current, indicated that more space charge present attheinterface between ZnO varistor ceramics and coating matarials will lead to lower withstanding flashover capability of ZnO bloeks sincc the electric field can be deviated due to the existence of interracial space charge．