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.

中文翻译：

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从具有超高价Fe4的B站点订购的双层钙钛矿Ca2FeMnO6连续和定点释放氧气。

与具有相同化学组成的B位无序钙钛矿相比，具有异常高价价Fe 4+的B位层有序双钙钛矿Ca 2 Fe Mn O 6具有异常的氧释放行为。在加热过程中，B位点有序化合物显示出逐步释放的氧，并且通过中间Fe3.5 +从Fe4 +到Fe3 +的价数连续变化，而B位点无序化合物在一个步骤中释放了氧气。Ca2FeMnO6中的氧仅从二维Fe层释放，并且这种选择性的氧释放以平面内氧空位有序地稳定了中间Fe3.5 +相。因此，B-位有序/无序强烈影响与氧空位排序相关的氧释放行为。