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Formation Mechanisms of Tetragonal Barium Titanate Nanoparticles in Alkoxide–Hydroxide Sol‐Precipitation Synthesis
Author(s) -
Yoon Songhak,
Baik Sunggi,
Kim Min Gyu,
Shin Namsoo
Publication year - 2006
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.1551-2916.2006.01056.x
Subject(s) - materials science , alkoxide , rietveld refinement , nanocrystalline material , titanate , tetragonal crystal system , anatase , xanes , nanoparticle , barium titanate , absorption edge , crystallography , inorganic chemistry , chemical engineering , crystal structure , chemistry , nanotechnology , ceramic , metallurgy , band gap , spectral line , photocatalysis , biochemistry , physics , optoelectronics , engineering , astronomy , catalysis
The early stage of barium titanate (BaTiO 3 ) nanoparticle formation is investigated by in situ X‐ray diffraction (XRD) and X‐ray absorption near‐edge structure (XANES) using synchrotron radiation. BaTiO 3 nanoparticles are synthesized via dissolution of barium hydroxide octahydrate and hydrolysis of titanium (IV) isopropoxide in isopropanol. In the course of raising the temperature of the alkoxide–hydroxide mixture solution to 80°C, in situ synchrotron XRD reveals that BaTiO 3 nanocrystals smaller than 6 nm begin to nucleate at 50°C without intermediate TiO 2 anatase formation, and Ti K edge absorption spectra also confirm the formation of corner‐sharing TiO 6 octahedra at 60°C. The average size of BaTiO 3 precipitates increases to about 7.5 nm at 80°C. The synthesized nanopowders show an anomalously high tetragonality according to the Rietveld refinement of synchrotron XRD data.