ic8b00381_si_001.pdf (5.24 MB)
Stabilization Mechanism of the Tetragonal Structure in a Hydrothermally Synthesized BaTiO3 Nanocrystal
journal contribution
posted on 2018-04-16, 12:33 authored by Kenta Hongo, Sinji Kurata, Apichai Jomphoak, Miki Inada, Katsuro Hayashi, Ryo MaezonoHigher
OH concentration is identified in tetragonal barium titanate (BaTiO3) nanorods synthesized by a hydrothermal method with a 10
vol % ethylene glycol solvent (Inada, M.; et al. Ceram. Int. 2015, 41, 5581–5587). This
is apparently inconsistent with the known fact that higher OH concentration
in the conventional hydrothermal synthesis makes pseudocubic BaTiO3 nanocrystals more stable than the tetragonal one. To understand
where and how the introduced OH anions are located and behave in the
nanocrystals, we applied ab initio analysis to several possible microscopic
geometries of OH locations, confirming the relative stability of the
tetragonal distortion over the pseudocubic one because of the preference
of trans-type configurations of OH anions. We also performed Fourier
transform infrared and X-ray diffraction analysis, all being consistent
with the microscopic picture established by the ab initio geometrical
optimizations.