TY - JOUR
T1 - Synthesis and characteristics of near-stoichiometric barium titanate powder by low temperature hydrothermal reaction using titanium tetra(methoxyethoxide)
AU - Woo, Kyoungja
AU - Choi, Guang J.
AU - Sim, Sang J.
AU - Cho, Young S.
AU - Kim, Young D.
N1 - Funding Information:
This research has been conducted under KIST-2000 program sponsored by Minister of Science and Technology in Korea.
PY - 2000/9
Y1 - 2000/9
N2 - Near-stoichiometric BaTiO3 powders with ultrafine particle size and high crystallinity were prepared by low temperature hydrothermal reaction of Ba(OAc)2 and Ti(OCH2CH2OCH3)4. BaTiO3 particles were synthesized in the spherical, metastable cubic crystalline grains with size distribution between 60-90 nm in diameter. Ultrafine particle size was resulted from the control of the hydration rate and the decrease of Ti-O-Ti cross-linking extent of titanium precursor, Ti(OCH2CH2OCH3)4, which gives electronic, steric, and weakly chelating effect to titanium ion. Increasing the Ba/Ti mole ratio in reactant could not overcome the notorious Ba-deficiency but, improved stoichiometry and produced finer and less agglomerated particles. Interestingly, adding a slight pressure to autogeneous hydrothermal condition (total 4-10 atm) has yielded near-stoichiometric, highly crystalline, and less agglomerated BaTiO3 particles. These particles, which were in metastable cubic form as synthesized, initiated phasetransition to tetragonal form by calcination at below 400 °C.
AB - Near-stoichiometric BaTiO3 powders with ultrafine particle size and high crystallinity were prepared by low temperature hydrothermal reaction of Ba(OAc)2 and Ti(OCH2CH2OCH3)4. BaTiO3 particles were synthesized in the spherical, metastable cubic crystalline grains with size distribution between 60-90 nm in diameter. Ultrafine particle size was resulted from the control of the hydration rate and the decrease of Ti-O-Ti cross-linking extent of titanium precursor, Ti(OCH2CH2OCH3)4, which gives electronic, steric, and weakly chelating effect to titanium ion. Increasing the Ba/Ti mole ratio in reactant could not overcome the notorious Ba-deficiency but, improved stoichiometry and produced finer and less agglomerated particles. Interestingly, adding a slight pressure to autogeneous hydrothermal condition (total 4-10 atm) has yielded near-stoichiometric, highly crystalline, and less agglomerated BaTiO3 particles. These particles, which were in metastable cubic form as synthesized, initiated phasetransition to tetragonal form by calcination at below 400 °C.
UR - http://www.scopus.com/inward/record.url?scp=0034271941&partnerID=8YFLogxK
U2 - 10.1023/A:1004868621334
DO - 10.1023/A:1004868621334
M3 - Article
AN - SCOPUS:0034271941
SN - 0022-2461
VL - 35
SP - 4539
EP - 4548
JO - Journal of Materials Science
JF - Journal of Materials Science
IS - 18
ER -