| 초록 |
BaTiO3 has been widely applied in electronic devices, especially in multilayer ceramic capacitor (MLCC), due to its high dielectric constant. The advances in electronic devices require implementation of ultra-high capacity MLCC. As dielectric layer material for ultra-high capacity MLCC, it has become a necessity to use BaTiO3 powder that has size below 200nm and maintains high dielectric property despite its size effect. Homogeneous existence of SrTiO3 in BaTiO3 leads to broadening of dielectric permittivity peak. Mixture of SrTiO3 and BaTiO3 may result inhomogeneous distribution between two components. However, the synthesis of core-shell structure of two component is one of promising approaches to achieve homogeneous distribution of BaTiO3 and SrTiO3, resulting broadened permittivity peak. Core-shell structure of BaTiO3 core and SrTiO3 shell has been investigated with relatively large BaTiO3 particle size. On BaTiO3 core with size around 100nm, TiO2 layer is synthesized as a precursor to SrTiO3@BaTiO3 core-shell structure. SrTiO3 shell is synthesized by hydrothermal process. Morphology and microstructure of SrTiO3@BaTiO3 core-shell structure have been investigated via scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). |
