Structure and Pt magnetism of FePt nanoparticles investigated with X-ray diffraction

Abstract Films consisting of 3D ordered arrays of FePt nanoparticles of ∼5 nm in size have been investigated with X-ray diffraction. At low angles, the diffracted intensities provide some evidence that the nanoparticles have an outer shell less dense than their interior. At high angles, the superstructure reflections have been used to evaluate the order parameter. Resonant magnetic diffraction at the Pt LIII absorption edge indicates that the magnetic moment of the Pt atoms in an Fe38Pt62 nanoparticle film is significantly smaller than that from a bulk alloy with similar composition.