Critical reexamination of resonant soft x-ray Bragg forbidden reflections in magnetite
Résumé
Magnetite, Fe3O4 , displays a highly complex low-temperature crystal structure that may be charge and orbitally ordered. Many of the recent experimental claims of such ordering rely on resonant soft x-ray diffraction at the oxygen K and iron L edges. We have reexamined this system and undertaken soft x-ray diffraction experiments on a high-quality single crystal. Contrary to previous claims in the literature, we show that the intensity observed at the Bragg forbidden (00(1)/(2))c reflection can be explained purely in terms of the low-temperature structural displacements around the resonant atoms. This does not necessarily mean that magnetite is not charge or orbitally ordered but rather that the present sensitivity of resonant soft x-ray experiments does not allow conclusive demonstration of such ordering.
Domaines
Autre [cond-mat.other]Origine | Fichiers produits par l'(les) auteur(s) |
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