Size dependent dielectric properties in BaTiO₃ nanopowders for application of MLCC

With the development of technology, electronic devices are constantly improving in performance, leading to an increase in the number of components. Consequently, there is a need to downsize passive components such as multi-layer ceramic capacitors (MLCCs). As a result, the size of the dielectric material used in MLCCs, namely BaTiO₃, must also be reduced. However, previous studies have primarily investigated the dielectric properties of BaTiO₃ nanopowders using the slurry method, of which approach has limitations as it combines the dielectric properties of both nanopowders and solvent. In this study, we employed scanning dielectric microscopy (SDM) to individually measure the dielectric constants of single BaTiO₃ nanopowders. We demonstrate dielectric constant dependent on the size of nanopowder. Furthermore, the variation in dielectric constant can be attributed to the surface cubic layer of BaTiO₃ nanopowders. Our findings revealed a peak dielectric constant of 60 occurring at an approximate nanopowder size of 55 nm, a phenomenon explicable through a three-phase structural model. This exploration into the nanoscale characteristics of BaTiO₃ holds promise for advancing the development of next-generation MLCCs.