Synthesis of fine BaTiO
3 powder through mechanochemically prepared precursors has been investigated. The precursors were prepared from Ba(OH)
2·8H
2O and TiO
2 by wet planetary mill treatment using acetone as a liquid medium. Pseudo-cubic BaTiO
3 was obtained after heat treatment of the precursors at 700°C for 3h. Anatase, rutile, Ba
6Ti
17O
40 and other titanates did not form during thermal treatment. The BaTiO
3 powder were sintered to densities more than 94% of the theoretical at 1250°C for 1h. The sintered materials showed a homogeneous microstructure consisting of fine grains less than 1μm, which was close to the optimum grain size for BaTiO
3 having a high dielectric constant. The well-mixed composite precursors consisting of Ba(OH)
2·xH
2O and hydrous TiO
2 were synthesized by the following successive processes; (1) extraction of hydrated water into the liquid media, (2) mechanochemical hyration of TiO
2, and (3) alloying of dehydrated Ba(OH)
2·xH
2O and hydrated TiO
2, for example TiO
2·H
2O and TiO(OH)
2, although the reactions were not completed.
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