PREPARATION OF BATIO3 THIN-FILMS USING GLYCOLATE PRECURSOR

The translucent grease-like gel was obtained by heating the mixed solu tion of monohydrated barium hydroxide and titanium isopropoxide in eth ylene glycol up to 145 degrees C, The gel consisted of EG (ca. 90%) an d residual flake-like microcrystals with a characteristic low-angle X- ray diffraction peak (d = 1.187 nm). The thermal decomposition of the gel proceeded through three major stages, viz., (i) evolution of EG (s imilar to 200 degrees C), (ii) decomposition of EG moiety in microcrys tal to form an amorphous carbonate (similar to 400 degrees C), and (ii i) crystallization of cubic BaTiO3 with a grain size of 10 to 20 nm (s imilar to 600 degrees C). Spectroscopic and thermoanalytical technique s were used to characterize the glycolate precursor and the intermedia te isolated at various stages. Smooth and transparent BaTiO3 films wit h 2-3 mu m thickness were obtained by painting the gel once on several substrates and heating up to above 600 degrees C, BaTiO3 films prepar ed were strongly oriented along the (110) plane. (C) 1997 Academic Pre ss.