Effect of milling process on core-shell microstructure and electrical properties for BaTiO3-based Ni-MLCC

The effect of the process parameter in the milling process on the microstructural evolution and the electrical properties of multilayer ceramic capacitor (MLCC) samples were investigated in the BaTiO3 (BT)–Ho2O3–MgO system. The microstructure for MLCC samples fired at 1320°C was dependent on the degree of damage for BT given by the milling process, judging from the field emission scanning electron microscopy observation and differential scanning calorimetry measurement (DSC). The mean grain size (D50) determined from the chemically etched samples decreased as the damage increased. The endothermic peak of DSC profile at around 125°C was broadened and the peak area decreased as the damage increased. Furthermore, the electrical properties were dependent on the degree of damage. The dielectric constant for MLCC samples decreased and the peak of dielectric constant at around room temperature shifted to a higher temperature as the damage increased. It was found that the MLCC sample showed the small leakage current and long mean lifetime as the degree of damage increased.