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Vacancy‐Induced Electronic Structure Variation of Acceptors and Correlation with Proton Conduction in Perovskite Oxides
Author(s) -
Kim HyeSung,
Jang Ahreum,
Choi SiYoung,
Jung WooChul,
Chung SungYoon
Publication year - 2016
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201603835
Subject(s) - valence (chemistry) , acceptor , vacancy defect , proton , trapping , chemical physics , perovskite (structure) , chemistry , dopant , oxygen , cluster (spacecraft) , materials science , crystallography , condensed matter physics , doping , physics , ecology , optoelectronics , organic chemistry , quantum mechanics , biology , computer science , programming language
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.