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arXiv · 1804.02865

Stabilization mechanism of tetragonal structure in hydrothermal synthesized BaTiO$_3$ nanocrystal

Kenta Hongo·Sinji Kurata·Apichai Jomphoak·Miki Inada·Katsuro Hayashi·Ryo Maezono
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Abstract

Higher OH concentration is identified in tetragonal barium titanate (BaTiO$_3$) nanorods synthesized by a hydrothermal method with 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 pseudo-cubic BaTiO$_3$ 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 pseudo-cubic one due to the preference of trans-type configurations of OH anions. We also performed FTIR and XRD analysis, all being in consistent with the microscopic picture established by the $ab$ $initio$ geometrical optimizations.

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Kenta Hongo, Sinji Kurata, Apichai Jomphoak, Miki Inada, Katsuro Hayashi, Ryo Maezono. 2018-04-09. Stabilization mechanism of tetragonal structure in hydrothermal synthesized BaTiO$_3$ nanocrystal. https://doi.org/10.1021/acs.inorgchem.8b00381

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