Relationship between the Microstructure and Electrical Properties for a Multilayer Ceramic Capacitor with a Ni Internal Electrode

摘要

The influence of the active layer thickness for a multilayer ceramic capacitor with a Ni internal electrode in barium zirconium taitanate (BTZ) based material was investigated. The dielectric constant (#epsilon#) increased irrespective of the active layer thickness with heat treatment in a weakly oxidizing atmosphere on a cooling stage during firing cycle (reoxidation treatment). The temperature dependence of #epsilon# was greatly dependent on the active layer thickness. The peak of #epsilon# for the sample with a reoxidation treatment shifted to a lower temperature accompanied by broadening as the active layer thickness decreased. The temperature dependence of #epsilon# for the sample with a reoxidation treatment and having various active layer thicknesses could be partly explained by the electrical field strength. The weight of the sample increased after the reoxidation treatment. The frequency response measured for samples with and without a reoxidation treatment revealed that the former showed dispersion of the imaginary part of permittivity and that the latter was conductive.