| 초록 |
Since barium titanate (BaTiO3) is one of primary functional materials due to its superior dielectric and ferroelectric properties, it has been widely used as a dielectric material in multi-layer ceramic capacitors (MLCCs). In recent years, the demand for higher capacitance of MLCCs have increased, requiring more dielectric layers in the same size of MLCC. Thus, extensive research on nano-sized BaTiO3 has been conducted to reduce the thickness of each dielectric layer. However, in the nanoscale regime, the dielectric properties of BaTiO3 nanoparticles decrease as the particle size decreases (so-called size-effect). In this point of view, it is necessary to understand the real structure of the nano-sized BaTiO3. Bragg coherent X-ray diffraction imaging (BCDI) is a lensless imaging technique and a powerful technique for visualizing internal structure of sub-nanometer-sized single particle. We utilized the BCDI technique to investigate the internal structure of BaTiO3 nanoparticles (e.g. 200 nm-size and 100 nm-size). We obtained the three dimensional Bragg X-ray diffraction data of BaTiO3 nanoparticles at the 9C-CXS beamline at the Pohang Light Source (PLS-II, Pohang Accelerator Laboratory), and reconstructed three dimensional images of BaTiO3 nanoparticles from the diffraction data. This study can provide the visualization of internal structure of BaTiO3 nanoparticle more intuitively. |
