Goto M, Martínez de Irujo-Labalde X, Saito T, García-Martín S, Shimakawa Y. Successive and Site-Selective Oxygen Release from B-Site-Layer-Ordered Double Perovskite Ca
2FeMnO
6 with Unusually High Valence Fe
4.
Inorg Chem 2020;
59:2024-2029. [PMID:
31944686 DOI:
10.1021/acs.inorgchem.9b03374]
[Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
B-site-layer-ordered double perovskite Ca2FeMnO6 with unusually high valence Fe4+ was found to exhibit unusual oxygen-release behaviors, contrasting with those of the B-site-disordered perovskite having the identical chemical composition. During heating, the B-site-layer-ordered compound shows a stepwise oxygen release with successive valence changes from Fe4+ to Fe3+ through an intermediate Fe3.5+, whereas the B-site-disordered compound releases oxygen in a single step. The oxygen in Ca2FeMnO6 is released only from the two-dimensional Fe layers, and this selective oxygen release stabilizes the intermediate Fe3.5+ phase with in-plane-oxygen-vacancy ordering. Therefore, the B-site order/disorder strongly affects the oxygen-release behaviors associated with the oxygen-vacancy ordering.
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