Influence of Firing Temperature on the Microstructure and Electrical Properties of BTZ Based Dielectric Material for Ni-MLCC

摘要

The influence of the microstructure on the redox behavior in barium zirconium titanate (BTZ)- based materials was investigated. The mean grain size was the largest for the chip fired at l230 deg.C, in Which there was only one grain per layer between Ni internal electrodes. A comparison of the temperature characteristics of the dielectric constant (8) between the chips fired in a reducing atmosphere (as-reduced sample) and those treated in a weakly oxidizing atmosphere revealed that the degree of ε increase was constant after the reoxidation treatment. The dependence of ε on the direct current bias field was larger for the as-reoxed sample than for the as- reduced one. On examination of the frequency response at the elevated temperature, the as-reduced samples showed two dielectric relaxations while the as-reoxed samples showed only one relaxation, irrespective of the firing temperature.