导　　师： 邓文

学科专业： 080502

授予学位： 硕士

作　　者： ;

机构地区： 广西大学

摘　　要： 本文系统研究了CaCO/_3、Fe/_2O/_3和CuO掺杂对ZnO-Bi/_2O/_3-Sb/_2O/_3-Co/_2O/_3-MnO/_2-Cr/_2O/_3系压敏陶瓷的电性能的影响；测量了CaCO/_3、Fe/_2O/_3和CuO掺杂的ZnO-Bi/_2O/_3-Sb/_2O/_3-Co/_2O/_3-MnO/_2-Cr/_2O/_3系压敏陶瓷片的符合正电子湮没辐射的Doppler展宽谱；通过分析实验数据，研究并讨论掺入CaCO/_3、Fe/_2O/_3和CuO所引入的阳离子杂质对ZnO-Bi/_2O/_3-Sb/_2O/_3-Co/_2O/_3-MnO/_2-Cr/_2O/_3系压敏陶瓷电性能和微结构的影响的微观作用机理，实验结果如下： /(1/)随着掺杂CaCO/_3摩尔含量的增加，ZnO压敏陶瓷的压敏电压V/_/(1mA/)升高、漏电流减小、非线性系数增大；ZnO压敏陶瓷的Doppler展宽的商谱峰值减小。 这可以解释为：在ZnO压敏陶瓷掺杂CaCO/_3时，Ca离子主要在晶界析出，固溶在ZnO晶粒边界形成固溶相颗粒，抑制晶粒增长，使ZnO晶粒减小，从而提高压敏电压，降低漏电流，增大非线性系数；同时由于掺杂CaCO/_3抑制了晶粒长大，增加了单位厚度的晶界数，促使陶瓷体中的微缺陷增多，从而使ZnO压敏陶瓷的Doppler展宽的商谱谱峰下降。 /(2/)随Fe/_2O/_3掺杂量的增加，ZnO压敏陶瓷的压敏电压V/_/(1mA/)和非线性系数先下降，后升高，最小值出现在Fe/_2O/_3摩尔掺杂量为1．00％；而漏电流和Doppler展宽的商谱谱峰先升高，后降低，最大值也出现在Fe/_2O/_3摩尔掺杂量为1．00％。 产生这些变化的原因是：Fe/_2O/_3掺杂量较少，未超过1．00％时，Fe/_2O/_3主要固溶至ZnO晶格，形成施主杂质，增加载流子浓度，增大漏电流，降低压敏电压，减小非线性系数；同时由于Fe的核外高动量电子比Zn的核外高动量电子多，Fe/_2O/_3固溶至ZnO晶格时，增加了高动量电子密度，引起ZnO压敏陶瓷的Doppler展宽的商谱谱峰升高。当Fe/_2O/_3掺杂量超过1．0％时，Fe/_2O/_3大量形成绝缘的Zn/_7Sb/_2O/_/(12/)-ZnFe/_2O/_4固溶体 In this paper, the effects of CaCO/_3、Fe/_2O/_3 and CuO doping content on properties of ZnO-Bi/_2O/_3-Sb/_2O/_3-Co/_2O/_3-MnO/_2-Cr/_2O/_3 varistor have been systematically studied; and the coincidence Doppler broadening spectrum measurements have been performed in CaCO/_3, Fe/_2O/_3 and CuO doped ZnO-Bi/_2O/_3-Sb/_2O/_3-Co/_2O/_3-MnO/_2-Cr/_2O/_3 ceramic varistors. In analyzing the experimental data, the micro-mechanism of the effects of the cationic impurities, which introduced by doping CaCO/_3, Fe/_2O/_3 and CuO, on the varistor properties and microstructure of the ZnO ceramic varistor has been studied and discussed. The experimental results are as follows: /(1/) With the increase of the CaCO/_3 content in ZnO varistor, the varistor voltage V/_/(1mA/) increasing; leakage current decreasing, non-linear coefficient increasing and the height of the peaks in the ratio curves of Doppler broadening spectrum of ZnO varistor decreasing. This can be explained as follows: in ZnO varistor doped CaCO/_3, Ca ion precipitation mainly in the grain boundaries, soluted on the ZnO grain boundary in the form of solid particles and inhibit grain growing, so that the ZnO grains decreased, thereby increasing the varistor voltage, reducing the leakage current, increasing the non-linear coefficient. At the same time, the addition of CaCO/_3 will inhibit grain growing and increase the grain boundaries or the defect concentration, so that the peaks in the ratio curves of Doppler broadening spectrum of ZnO varistor Ceramics decrease. /(2/) With the increase of the addition of Fe/_2O/_3 into ZnO varistor ceramic, the varistor voltage V/_/(1mA/) and the non-linear coefficient decrease firstly and then increase, the minimum values have been found at the Fe/_2O/_3 content of 1.00/% /(molar volume/); while the leakage current and the height of the peaks in the ratio curves increase firstly and then decrease; the maximum values have also been found at the Fe/_2O/_3 content of 1.00/% /(molar volume/). The reasons for th

关 键 词： 压敏陶瓷 符合正电子湮没辐射 展宽谱 压敏电压 漏电流 非线性系数 微观缺陷 掺杂

领　　域： [电气工程] [一般工业技术]