CaCO3对TiO2系压敏陶瓷性能的影响

摘要

采用传统的固相烧结工艺制备了TiO2系压敏陶瓷.通过对其晶体结构、表面形貌分析和对样品压敏性能、介电性能的测定,研究了不同CaCO3含量对TiO2压敏陶瓷性能的影响.研究发现:在1300℃烧结条件下,掺入0.50 mol％ CaCO3的样品具有非常致密的微观结构,晶粒的均匀性最好;除TiO2金红石晶相外,还存在着第二相;具有良好的综合电性能,显示出低的压敏电压(E1mA=2.07 V/mm)、高的非线性系数(α=3.35)、最高的介电常数(εr=2.60×105)和相对低的介电损耗(tan δ=0.23).%TiO2 varistor ceramics were prepared by conventional solid state reaction.The surface morphology,crystal structure,varistor properties and dielectric properties of TiO2 varistor ceramics with different amounts of CaCO3 sintered at 1300 ℃ were investigated.The results showed that the samples doped with 0.50 mol％ CaCO3 had compact microstructure and homogeneous grains.Minor secondary phases were detected besides the matrix of TiO2 rutile phase.The optimal composition was obtained by doping with 0.50 mol％ CaCO3,which had the low breakdown voltage of 2.07 V/mm,the high nonlinear coefficient of 3.35,the highest dielectric constant of 2.60× 105 and the relative low tanδ of 0.23..