ABSTRACT This study investigated electrical properties and microstructure of zinc oxide varistors containing MnO2, Cr2O3, V2O5 and TiO2. To this end, nanosize ZnO particles were synthesised by the polyacrylamide-gel method and doped with minor amounts of MnO2 (0.5 mol-%), Cr2O3 (0.5 mol-%), V2O5 (2 mol-%) and TiO2 in the range of 2–15 mol-%. The prepared samples sintered at 1050°C in air for 2 h. It was observed that TiO2 promoted grain growth of ZnO particles. X-ray examination showed hexagonal ZnO structure as a main phase and Zn2TiO4 and ZnV2O4 as minor secondary phases. The nonlinear coefficient and threshold voltage of the prepared samples were in the range of 3.3–7.9 and 1120–4700 V cm−1 respectively, in which both of them increased with increase in TiO2 content. Among the prepared samples, the varistor with 15 mol-% TiO2 exhibited the best performance in terms of nonlinearity. The nonlinear electrical behaviour was explained by theory of formation of the potential barriers at grain boundaries.

中文翻译：

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TiO2 浓度对纳米 ZnO 颗粒制备的 ZnO 基压敏陶瓷电学和微观结构的影响

摘要 本研究调查了含有 MnO2、Cr2O3、V2O5 和 TiO2 的氧化锌压敏电阻的电性能和微观结构。为此，通过聚丙烯酰胺凝胶法合成纳米尺寸的 ZnO 颗粒，并在以下范围内掺杂少量 MnO2 (0.5 mol-%)、Cr2O3 (0.5 mol-%)、V2O5 (2 mol-%) 和 TiO2 2–15 mol-%。制备的样品在空气中在 1050°C 下烧结 2 小时。观察到 TiO2 促进了 ZnO 颗粒的晶粒生长。X 射线检查显示六方 ZnO 结构为主相，Zn2TiO4 和 ZnV2O4 为次要第二相。制备的样品的非线性系数和阈值电压分别在 3.3-7.9 和 1120-4700 V cm-1 范围内，其中两者都随着 TiO2 含量的增加而增加。在制备的样品中，含 15 mol-% TiO2 的压敏电阻在非线性方面表现出最佳性能。通过在晶界形成势垒的理论来解释非线性电学行为。