Resonant x-ray diffraction study of the charge ordering in magnetite

Abstract

Powder x-ray diffraction patterns of magnetite (Fe3O4) have been recorded at 90 K, below the Verwey transition, at three wavelengths in the pre- to mid-edge region of the 7.1 keV Fe K absorption. Simultaneous fitting of these profiles has been used to refine the anomalous scattering coefficients for the octahedral B site iron atoms. The refined values give direct evidence for a significant degree (46%) of Fe2+/Fe3+ charge ordering in magnetite, and provide new constraints on the number of possible charge ordered models.