Absorption spectroscopy and XMCD at the Verwey transition of Fe3O4

Abstract Fe 3 O 4 has been investigated since decades, because of its magnetic and unusual electronic transport properties, which exhibit significant changes at the so-called Verwey transition, despite the promising high-spin polarization at the Fermi energy. We will show detailed and angular-dependent magnetic (XMCD) and nonmagnetic (XAS) absorption spectroscopy results of a high-quality single crystal, comparing cleaved and polished surfaces from the same single crystal. While the cleaved sample exhibits the full spin moment of magnetite, the same sample with a polished surface exhibits a magnetic moment reduced by a factor of 2, indicating a reduced surface magnetization. Angular-dependent XMCD measurements do not exhibit any significant variation. These results are consistent to recently published photoemission data.