BaTiO3 (BT) is a typical ferroelectric material used in capacitors. For miniaturization of devices, nanoscale BT
research has been actively conducted, along with research on the enhanced dielectric properties of
nano-capacitor materials. The ferroelectricity of BT at room temperature is strongly related to its tetragonal
crystal structure. It has been reported that the dielectric constant increases as BT particle size decreases.
However, below a certain critical size, ferroelectricity of BT disappears and it exhibits characteristics of a cubic
crystal structure at room temperature. Various measurement methods have been deployed to study the
relationship between particle size and structure and the compound’s ferroelectricity. Among them, small angle
/ ultra-small angle X-ray scattering has been used to investigate the particle size of powder materials
non-destructively, without dilution. Here, the average particle size and the size distribution of a BT powder are
evaluated by ultra-small angle X-ray scattering.