1995 年 32 巻 3 号 p. 164-169
A core-shell type composite powder was prepared by the hydrolysis of titanium tetraisopropoxide or ethyl silicate in the dispersion of BaCO3 core particles which adsorbed water in hexane. Core particles of the composite powder were dissolved in acetic acid solution, and micro porous cells were thus obtained.
The content of titania in the BaCO3-TiO2 composite powder was controlled by the amount of water adsorbed. The pore volume of the micro porous cells increased with the titania content of the composite powder after the dissolution of the core particles.
The BaCO3-TiO2 composite powder was heated at 600°C for 10 hours, and barium ions in core particles were diffused to titania. The micro porous cells composed of the BaTiO3 ultra-fine particles were thus created after the BaCO3 core particles were dissolved.