The multiferroic LuFe^2.5+₂O₄ was recently proposed as a promising material for oxygen storage due to its easy reversible oxidation into LuFe³⁺₂O_4.5. We have investigated the similar scenario in YbFe₂O_4+x, leading to a slightly greater oxygen storage (OSC) capacity of 1434 μmol O/g. For the first time, the structural model of LnFe₂O_4.5 was fully understood by high-resolution microscopy images, and synchrotron and neutron diffraction experiments, as well as maximum entropy method. The oxygen uptake promotes a reconstructive shearing of the [YbO₂] sub-units controlled by the adaptive Ln/Fe oxygen coordination and the Fe^2/3+ redox. After oxidation, the rearrangement of the Fe coordination polyhedra is unique such that all available FeO_n units (n = 6, 5, 4 in octahedra, square pyramids, trigonal bipyramids, tetrahedra) were identified in modulated rows growing in plane. This complex pseudo-ordering gives rise to short-range antiferromagnetic correlation within an insulating state.

中文翻译：

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储氧的YbFe综合研究₂ Ø _{4+ X}（X前所未有的FeO共存：≤0.5）_ñ多面体在一组单相

最近，人们提出将多铁性LuFe ^2.5+ ₂ O ₄用作有希望的储氧材料，因为它易于可逆地氧化成LuFe ³⁺ ₂ O _4.5。我们已经研究了YbFe ₂ O _{4+ x中}的类似情况，导致储氧量（OSC）略高，为1434μmolO / g。高分辨率显微镜图像，同步加速器和中子衍射实验以及最大熵方法首次完全理解了LnFe ₂ O _4.5的结构模型。吸氧促进了[YbO ₂的重建剪切]子单元由自适应Ln / Fe氧配位和Fe ^{2/3 +}氧化还原控制。氧化后，Fe配位多面体的重排是独特的，从而可以在平面中生长的已调制行中识别出所有可用的FeO _n单元（八面体，方形金字塔，三棱锥，四面体中的n = 6、5、4）。这种复杂的伪排序在绝缘状态下产生了短程反铁磁相关性。