ゾル-ゲル法によるチタン酸バリウムモノリシックゲルの局所構造と室温結晶化機構

概要

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An investigation has been made on the local structure and the gel to crystalline conversion mechanism in BaTiO_3 monolithic gels derived from hydrolysis of concentrated Ba, Ti alkoxide precursor solutions with a Ba/Ti molar ratio of 1.00 during aging at 30℃ by means of XRD, Ba L_<III>-edge EXAFS, Ti K-edge XANES, and ICP. The results indicate that local structures of amorphous monolithic gels obtained immediately after gelation consisted of Ba-TiO_6 clusters coordinated with alkoxyl or hydroxyl ligands as a structural unit, which underwent condensation polymerization by corner-sharing of TiO_6 octahedra to form a three-dimensional gel-network. The conversion of gel to crystalline barium titanate nano-particles durign aging at 30℃ can be explained by a model that the crystalline phase directly forms from the amorphous phase without dissolution, deposition and diffusion of the reactant species nor generation of intermediate phases.
社団法人日本セラミックス協会の論文
1997-09-01