Study of Phase Stability and Hydride Diffusion Mechanism of BaTiO3 Oxyhydride from First-Principles

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• 作者：Jiajia Zhang ; Gaoyang Gou ; Bicai Pan
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：August 7, 2014
• 年：2014
• 卷：118
• 期：31
• 页码：17254-17259
• 全文大小：391K
• ISSN：1932-7455

文摘

First-principles calculations were performed to study structural, electronic and hydride diffusion properties of BaTiO₃ oxyhydride. In agreement with experiment (Nat. Mater. 2012, 11, 507 and J. Am. Chem. Soc. 2012, 134, 8782), we find that the incoming H species occupy the anion vacancy sites left by oxygen, forming the stable hydride anions H^鈥?. As a result of the electron doping introduced by H species, both interstitial H and hydride anion H^鈥? can induce metallicity and eliminate ferroelectricity in BaTiO₃. We further clarify the role of the migration of the interstitial H in determining the hydrogen diffusion properties of the oxyhydrides. A low diffusion barrier was predicted, responsible for high hydrogen diffusion mobility observed in experiment. Based on our results, we demonstrate that BaTiO₃ oxyhydride can be used as a mixed electron/hydride conductor, displaying the promising applications as the electrolytes for solid-oxide fuel cells.