Preparation of Tetragonal Barium Titanate Thin Film on Titanium Metal Substrate by Hydrothermal Method |
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Authors: | Koji Kajiyoshi Nobuo Ishizawa Masahiro Yoshimura |
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Affiliation: | Research Laboratory of Engineering Materials, Tokyo Institute of Technology, Yokohama 227, Japan |
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Abstract: | Tetragonal BaTiO3 thin films were prepared directly on Ti metal substrates in Ba(OH)2 solutions by a hydrothermal method at temperatures 400° to 800°C for 5 to 240 min. The film thickness estimated from weight gain of Ti plate was in the range from 0.5 to 2.5 μm, and it increased with increasing treatment temperature, treatment time, and Ba(OH)2 concentration. Rectangular crystals having {100} and {001} faces grew idiomorphically with approximate crystal size of 0.3 to 2.0 μm. The tetragonality of the BaTiO3 films became apparent when the average crystal size exceeded about 1 μm. Lattice parameters of the films were a = 3.994 Å, c = 4.035 Å, and c/a = 1.010. The films formed above 600°C had preferred orientation showing stronger XRD peaks of h 00 and 00 l than the other peaks. |
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Keywords: | barium titanate hydrothermal process thin films morphology crystallinity |
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