SYNCHROTRON X-RAY-SCATTERING STUDIES OF MAGNETIC-MATERIALS

With the recent development of resonant techniques,1 -3 interest in x-ray magnetic scattering as a probe of magnetic and electronic structure has been steadily increasing. Significant efforts now exist at most of the x-ray storage rings around the world. These have led to proposals for dedicated beamlines at the Advanced Photon Source and at the European Synchrotron Radiation Facility planned for Argonne and Grenoble, respectively. In this talk we describe recent results of polarization and resonance studies of rare-earth and actinide materials using synchrotron radiation. For incident x-ray energies far above an absoption edge, we measure the degree of linear polarization of the scattered beam and identify the orbital and spin contributions to the magnetic cross section.1 When the incident x-ray energy is tuned near the M and L absorption edges, large resonant enhancements of the magnetic cross section, and resonant harmonics, are observed.1-3 This behavior may be understood on the basis of electric multipole transitions to unoccupied magnetic states in the conduction band.2 These techniques provide new directions to x-ray magnetic scattering studies using synchrotron radiation, including possible applications to multilayer and surface magnetic structures, and to the spectroscopy of magnetic states in the rare-earth and actinide series.