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Optical Absorption in Sol‐Gel‐Derived Crystalline Barium Titanium Fine Particles
Author(s) -
Matsuda Hirofumi,
Kuwabara Makoto,
Yamada Kenichi,
Shimooka Hirokazu,
Takahashi Seiji
Publication year - 1998
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1998.tb02728.x
Subject(s) - barium titanate , materials science , alkoxide , tetragonal crystal system , absorption edge , crystallite , barium , titanium , absorption (acoustics) , sol gel , crystal (programming language) , analytical chemistry (journal) , band gap , absorption spectroscopy , crystal structure , mineralogy , crystallography , optics , ceramic , nanotechnology , chemistry , optoelectronics , composite material , metallurgy , biochemistry , physics , chromatography , computer science , programming language , catalysis
Pure, translucent, and highly crystallized barium titanate (BaTiO 3 ) monolithic gels were synthesized via a sol‐gel technique at temperatures down to 90°C by using a high‐concentration solution of barium alkoxide and titanium alkoxide. The gels consisted of fine particles with an average diameter of ~10 nm and showed the X‐ray diffraction patterns of a pseudo‐cubic BaTiO 3 system at room temperature; however, in bulk crystal, the tetragonal structure was more stable. The optical transmission spectra of the polycrystalline gels were similar to those for single‐crystalline BaTiO 3 . From the excitation energy dependence of the absorption‐edge structures, the optical‐gap energies for the gels were estimated to have values that were ~0.1 eV higher than those for the single crystal; these higher optical‐gap energies may be attributed to size effects.