添加Bi2WO6对ZnO基压敏陶瓷电学性能的影响

用传统固相反应法研究了添加Bi₂WO₆(x=0%~9%，质量分数)对ZnO基压敏陶瓷的微观结构、压敏性能和介电性能的影响。结果表明：掺入适量的Bi₂WO₆能促进ZnO压敏陶瓷晶粒均匀生长、提高微观结构的均匀性、降低压敏场强和提高非线性系数；同时，Bi₂WO₆的添加可提高ZnO晶粒表面吸附氧的含量，从而提高界面态密度和势垒高度以及ZnO基压敏陶瓷的非线性特性。Bi₂WO₆的添加量为7%的ZnO基压敏陶瓷，其综合性能为：E_{1 mA}=263 V/mm，α=53，J_L=3.50 μA/cm²，φ_b=11.52 eV。

Influence of Bi2WO6 on Electric Properties of ZnO Varistor Ceramics

The ZnO-based varistor ceramics with addition of different amount of Bi₂WO₆ were prepared by conventional solid state reaction and then their surface morphology and electrical properties were examined. Results show that appropriate Bi₂WO₆-dopping can promote the uniform growth of ZnO varistor ceramic grains, improve their uniformity of microstructure, reduce the breakdown voltage and increase the nonlinear coefficient. In addition, Bi₂WO₆ can increase the content of absorbed oxygen on the surface of ZnO, thereby enhance the density of the interfacial state and barrier height, correspondingly, optimize the nonlinear characteristic of ZnO varistor ceramics. For the ZnO-based varistor ceramics with x=7% (mass fraction) Bi₂WO₆, presents excellent properties: the nonlinear coefficient α is as high as 53, corresponding to the highly barrier height φ_b of 11.52 eV, whilst the leakage current J_L and the breakdown voltage are as low as 3.50 μA/cm² and 263 V/mm, respectively.