カーボンナノホーン中でのBaTiO₃超微粒子の合成

抄録

Porous carbons have the potential to be an ideal template for various materials, because of their simple geometry and various shapes. We synthesized BaTiO₃ nanocrystals in the internal nanopores of carbon nanohorns by sol-gel methods. Direct synthesis of BaTiO₃ in carbon nanohorns produced 2∼4 nm diameter spherical particles, although a typical sol-gel technique for nanoceramic synthesis produces spherical crystals with a diameter of the order of 10 nm. The BaTiO₃ nanoceramics were composed of only a few crystal unit cells, and can be considered zero-dimensional BaTiO₃ nanoceramics. BaTiO₃ nanoceramics synthesized by TiO₂ synthesis in carbon nanohorns and subsequent insertion of barium diethoxide were one-dimensional structures with a high aspect ratio (2∼4 nm in diameter and 40∼60 nm in length). Those nano-spherical and rod-like BaTiO₃ nanoceramics are required in nanotechnology for their unique dielectric and piezoelectric properties.