Discerning element and site-specific fluctuations of the charge-orbital order in Fe3O4 below the Verwey transition
Discerning element and site-specific fluctuations of the charge-orbital order in Fe3O4 below the Verwey transition
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DOI：
10.1103/physrevmaterials.7.014413
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发表时间：
2023-01-31
影响因子：
3.4
通讯作者：
Shpyrko，Oleg G.
中科院分区：
文献类型：
--
作者：
Hua，Nelson;Li，Jianheng;Shpyrko，Oleg G.
尽管在Verwey转变过程中对磁铁矿的电子结构进行了无数的实验探索，但这种典型的金属-绝缘体转变的确切起源仍然是一个谜。先进的x射线衍射技术大多解决了绝缘相的单斜晶系结构，包括原子间键长，但复杂的电荷轨道有序态很难解开。我们结合共振弹性x射线散射和x射线光子相关光谱来探测磁铁矿绝缘态下的电荷轨道涨落。通过访问氧边缘的Bragg禁止峰，我们补充了我们之前对铁的研究，以揭示铁和氧轨道域的动力学。我们的新结果揭示了含氧态和特定位置的铁态之间的轨道关联长度的解耦，并进一步显示了三聚体链的铁轨道位置的电荷-轨道域波动。这些结果还证明了一种实验方法，能够区分氧配体和支持复合氧化物中出现行为的过渡金属之间的电子动力学。
Despite countless experimental probes into magnetite's electronic structure across the Verwey transition, the exact origin of this archetypical metal-insulator transition remains a puzzle. Advanced x-ray diffraction techniques have mostly resolved the monoclinic structure of the insulating phase, including interatomic bond lengths, but the complexity of the charge-orbitally ordered state is difficult to disentangle. We combined resonant elastic x-ray scattering and x-ray photon correlation spectroscopy to probe charge-orbital fluctuations in the insulating state of magnetite. By accessing the Bragg forbiddenpeak at the oxygen-edge, we complement our previous study on the ironto reveal the dynamics of the ironand oxygenorbital domains. Our new results reveal a decoupling of the orbital correlation lengths between the oxygenstates and site-specific ironstates, and we further show charge-orbital domain fluctuations at the ironorbital sites of trimeron chains. These results also demonstrate an experimental method capable of distinguishing electronic dynamics between the oxygen ligands and the transition metal that underpins emergent behaviors in complex oxides.