Electronic and magnetic properties of highly ordered Sr2FeMoO6

Abstract

The electronic and magnetic properties of the colossal magneto resistance (CMR) compound Sr2FeMoO6 have been studied using different experimental techniques, namely X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and X-ray absorption spectroscopy (XAS). Furthermore, the magnetic properties have been studied in the temperature range of 4.2 K-800 K. The data confirm a highly ordered double perovskite crystal structure and is consistent with the tetragonal structure with 14/mmm symmetry. The Fe L edge has been probed by means of XAS, and comparison with results for a series of other iron oxides reveals a mixed valence state of Fe2+ and Fe3+. XPS of the Mo 3d and Fe 3s core levels confirms this point of view indicating a mixed valence state involving around 30% Fe3+-Mo5+ and 70% Fe2+-Mo6+ states, in good agreement with paramagnetic measurements which suggest 60% Fe2+ ions. (C) 2004 WILEY-VCH Verlag GmbH & Co. KGa.A, Weinheim.