Vacancy-Induced Electronic Structure Variation of Acceptors and Correlation with Proton Conduction in Perovskite Oxides

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• 作者：Hye-Sung Kim ; Ahreum Jang ; Dr. Si-Young Choi ; Prof. WooChul Jung and Prof. Sung-Yoon Chung
• 刊名：Angewandte Chemie International Edition
• 出版年：2016
• 出版时间：October 17, 2016
• 年：2016
• 卷：55
• 期：43
• 页码：13499-13503
• 全文大小：2371K
• ISSN：1521-3773

文摘

In most proton-conducing perovskite oxides, the electrostatic attraction between negatively charged acceptor dopants and protonic defects having a positive charge is known to be a major cause of retardation of proton conduction, a phenomenon that is generally referred to as proton trapping. We experimentally show that proton trapping can be suppressed by clustering of positively charged oxygen vacancies to acceptors in BaZrO_3−δ and BaCeO_3−δ. In particular, to ensure the vacancy–acceptor association is effective against proton trapping, the valence electron density of acceptors should not significantly vary when the oxygen vacancies cluster, based on the weak hybridization between the valence d or p orbitals of acceptors and the 2p orbitals of oxygen.