Effects of the microstructure on dielectric properties for BaTiO3-based MLC with Ni electrode

Effects of the MgO addition on the microstructure and electrical properties were investigated in the Sm- and He-doped BaTiO3 based dielectric materials. The formation of core-shell microstructure and the grain growth were dependent on the amount of MgO and the kind of rare earth oxide. Larger amount of MgO was required to form the core-shell microstructure for Sm-doped samples than for He-doped samples. The microstructure had a decisive influence on the electrical properties, such as the temperature dependence of the dielectric constant, restoration of the resistivity on cooling, the aging of the capacitance under de electrical field, and the leakage current under the highly accelerated life lest. Particularly, a distinctive electrical properties were obtained for Sm-doped sample with 0.5mol% MgO, in which the core-shell microstructure was collapsed as judged by the DSC measurement and the TEM observation.