Berlin 2005 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 16: Posters Correlated Electrons, Measuring Devices, Cryotechnique
TT 16.90: Poster
Samstag, 5. März 2005, 11:00–16:30, Poster TU C
Resonant soft x-ray diffraction to study electronic order — •C. Schüßler-Langeheine1, J. Schlappa1, A. Tanaka2, C.-F. Chang1, Z. Hu1, M. Benomar1, H. Ott1, E. Schierle3, E. Weschke3, G. Kaindl3, M. Braden1, and L. H. Tjeng1 — 1II. Physikalisches Institut, Universität zu Köln — 2ADSM, Hiroshima University, Japan — 3Institut für Experimentalphysik, Freie Universität Berlin
Resonant diffraction in the soft x-ray range (RSXS) is a new tool, which is particularly suited to study superstructures formed by modulations of the electronic state, like differences in the valence or in the orbital occupation. Such kind of order can be found in various correlated-electron systems. RSXS as a combination of spectroscopy and diffraction is based on the strong sensitivity of resonances in the soft x-ray range, namely the transition-metal 2p → 3d, oxygen 1s → 2p and lanthanide 3d → 4f excitations, on details of the electronic state. This sensitivity leads to different scattering cross sections for sites with different electronic configurations and creates a photon-energy dependent contrast for the diffraction process. Already on a qualitative level by comparison between the x-ray absorption spectrum and the energy dependence of the diffracted intensity, signatures of electronic order can be detected. Furthermore, since resonances in the soft x-ray range are well understood, a detailed microscopic modeling of the resonant diffraction is feasible, providing direct spectroscopic information about the ordered part of the system.