Dresden 2006 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 25: Correlated Electrons - Poster Session

TT 25.113: Poster

Mittwoch, 29. März 2006, 14:30–18:30, P1

Probing orbital moment with resonant soft x-ray diffraction: La_1.5Sr_0.5CoO₄ — •C. Schüßler-Langeheine, C. F. Chang, Z. Hu, M. W. Haverkort, T. Burnus, M. Benomar, M. Braden, and L. H. Tjeng — II. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany

Magnetic circular dicroism in x-ray absorption (XMCD) is a well-established technique for the investigation of ferromagnetic materials. From the shape of the XMCD signal across resonance the z-component of the orbital and spin moments can be deduced - in many cases by means of a simple sum-rule analysis. We applied this technique to an antiferromagnetic system, which is Sr-doped La₂CoO₄. For an antiferromagnet the MCD effect cannot be observed in the x-ray absorption signal, where it cancels out, but MCD is also one of the contrast mechanisms leading to resonant magnetic x-ray scattering. For La_1.5Sr_0.5CoO₄ we find a vanishing magnetic diffraction signal at the Co-L₂ resonance, which indicates a large z-component of the orbital moment.