Development of particle size control method for production of Barium titanate nanocubes by Ibaraki University and others

The research group was composed of Associate Professor Kouichi Nakashima, Professor Yoshio Kobayashi, graduate student Kouta Hironaka, and graduate student Kazuma Oouchi of the Graduate School of Science and Engineering, Ibaraki University; Ms. Mao Ajioka of the College of Engineering, Ibaraki University; Professor Tohru Sekino of the Institute of Scientific and Industrial Research, Osaka University, Specially Appointed Professor Masato Kakihana and Professor Shu Yin of the Institute of Multidisciplinary Research for Advanced Materials, Tohoku University; and Principal Investigator Yasuhiro Yoneda of the Japan Atomic Energy Agency. They reported that the particle size of titanium oxide (TiO₂), which is the starting material, affects the particle size control of barium titanate (BaTiO₃) nanocubes.

BaTiO₃ is used as a ceramic capacitor for electronic devices, such as mobile phones and personal computers, and is an indispensable material in daily life. The aim of this research was to improve the performance of this ceramic capacitor by controlling the particle size of BaTiO₃ nanocubes. TiO₂ has been used for the synthesis of BaTiO₃ nanocubes, but the particle size distribution obtained by this method is large and needs to be reduced. If TiO₂ with a particle size of 25 nm or less and good dispersibility is used as a starting material, the amount of nucleation will increase, and the uniformity of BaTiO₃ nanocubes can be improved and fine particles of BaTiO₃ can be obtained. Therefore, the research group proceeded to synthesize TiO₂ nanoparticles with good dispersibility using a water-soluble titanium complex.

It was found that the particle size of TiO₂, which is a raw material, affects the particle size control of BaTiO₃. It was then clarified that the synthesis can be controlled by using an environment-friendly process and using TiO₂ raw material of small particle size and good dispersibility. The research group also succeeded in expressing the BaTiO₃ nanocube in three dimensions by electron tomography. Associate Professor Nakajima said, "If we can establish a technology to freely control the particle size of BaTiO₃ nanocubes in the future, we can expect a dramatic improvement in the dielectric constant. It is expected that electronic devices such as mobile phones and personal computers that are fami