Full polarization analysis of resonant superlattice and forbidden x-ray reflections in magnetite

S. R. Bland (1) , B. Detlefs (2) , S. B. Wilkins (3) , T. A. W. Beale (1) , Claudio Mazzoli (2) , Yves Joly (4) , P. D. Hatton (5) , José-Emilio Lorenzo (6) , V. A. M. Brabers (7)

1 Department of Physics
2 ESRF - European Synchrotron Radiation Facility
3 Brookhaven, Natl Lab.
4 NEEL - SIN - Surfaces, Interfaces et Nanostructures
5 Department of Physics
6 NEEL - MagSup - Magnétisme et Supraconductivité
7 Department of Applied Physics [Eindhoven]

Despite being one of the oldest known magnetic materials, and the classic mixed valence compound, thought to be charge ordered, the structure of magnetite below the Verwey transition is complex and the presence and role of charge order is still being debated. Here, we present resonant x-ray diffraction data at the iron K-edge on forbidden (0, 0, 2n + 1)C and superlattice (0, 0, 2n+1/2 )C reflections. Full linear polarization analysis of the incident and scattered light was conducted in order to explore the origins of the reflections. Through simulation of the resonant spectra we have confirmed that a degree of charge ordering takes place, while the anisotropic tensor of susceptibility scattering is responsible for the superlattice reflections below the Verwey transition. We also report the surprising result of the conversion of a significant proportion of the scattered light from linear to nonlinear polarization.

Mots clés: Resonant x-ray diffraction; resonant x-ray scattering; polarization analysis; Magnetite; Fe3O4

Domaines: Science des matériaux [cond-mat.mtrl-sci]

S. R. Bland, B. Detlefs, S. B. Wilkins, T. A. W. Beale, Claudio Mazzoli, et al.. Full polarization analysis of resonant superlattice and forbidden x-ray reflections in magnetite. Journal of Physics: Condensed Matter, 2009, 21, pp.485601. ⟨10.1088/0953-8984/21/48/485601⟩. ⟨hal-00691385⟩