Berlin 2008 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 32: Postersession II: Spinstruct./Phase Trans. (1-10); Spinelectronics (11-15); Thin Films (16 - 36); Particles/Clusters (37-45); Multiferroics (46-54); Spindynamics/Spin Torque (55 - 76); Post Deadlines (77-79)
MA 32.10: Poster
Freitag, 29. Februar 2008, 11:15–14:00, Poster E
Ordered orbital momentum in antiferromagnets from sum rules in soft x-ray resonant diffraction — •Marcel Buchholz1, Chun Fu Chang1, Maurits W. Haverkort1, Christian Schüßler-Langeheine1, Matthias Cwik1, Hsueh-Hung Wu1,2, Thomas Willers1, Zhiwei Hu1, Arata Tanaka3, Enrico Schierle4, Detlef Schmitz4, and L. Hao Tjeng1 — 1II. Physikalisches Institut, Universität zu Köln — 2NSRRC, Taiwan — 3ADSM, Hiroshima University, Japan — 4HMI c/o Bessy
Using sum rules applied to x-ray magnetic circular dichroism (XMCD) is a well established technique to extract, e.g., the orbital contribution to the magnetic moment in ferromagnets. For antiferromagnets (AF) such an extraction is a more difficult task because XMCD, which requires a net magnetic moment of the sample, cannot be applied here. A novel experimental approach particularly well suited for AF is the use of the sum rules valid for resonant soft x-ray magnetic diffraction. These rules allow to determine the ordered orbital momentum directly from the energy dependence of a magnetic diffraction peak near an electronic resonance [1]. The potential of this method for 3d and 4f systems is explored by application of sum rules to magnetic diffraction data from La1.5Sr0.5CoO4 and metallic Ho. The results are compared to those obtained by a microscopic modeling of the resonance spectra.
Supported by the DFG through SFB 608 and by the BMBF.
[1] M. W. Haverkort, C. Schüßler-Langeheine, A. Tanaka, to be published