Critical reexamination of resonant soft x-ray Bragg forbidden reflections in magnetite

Stuart B. Wilkins (1) , Sergio Di Matteo (2) , Thomas A. W. Beale (3) , Yves Joly (4) , Claudio Mazzoli (5) , Peter D. Hatton (3) , Peter Bencok (5) , Flora Yakhou (5) , V. A. M. Brabers (6)

1 Department of Condensed Matter Physics and Materials Science
2 Surfaces et interfaces
3 Department of Physics [Durham University]
4 NEEL - SIN - Surfaces, Interfaces et Nanostructures
5 ESRF - European Synchrotron Radiation Facility
6 Department of Applied Physics [Eindhoven]

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.

Mots clés: Strongly correlated electron systems; heavy fermions

Domaines: Autre [cond-mat.other]

Stuart B. Wilkins, Sergio Di Matteo, Thomas A. W. Beale, Yves Joly, Claudio Mazzoli, et al.. Critical reexamination of resonant soft x-ray Bragg forbidden reflections in magnetite. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2009, 79 (20), pp.201102. ⟨10.1103/PHYSREVB.79.201102⟩. ⟨hal-00663326⟩