Stuttgart 2012 – wissenschaftliches Programm

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MS: Fachverband Massenspektrometrie

MS 6: Poster

MS 6.7: Poster

Dienstag, 13. März 2012, 16:30–19:00, Poster.IV

Spin and orbital moments of isolated clusters - synchrotron radiation elucidates nanomagnetism — Sergey Peredkov¹, Matthias Neeb², Wolfgang Eberhardt¹, Jennifer Meyer³, Matthias Tombers³, and •Gereon Niedner-Schatteburg³ — ¹TU Berlin, Institut für Optik und Atomare Physik, Hardenbergstr. 36, 10623 Berlin, Germany — ²Helmholtz-Zentrum Berlin für Materialien & Energie, BESSY II, Albert-Einstein-Str. 15, 12489 Berlin, Germany — ³TU Kaiserslautern, Fachbereich Chemie und Foschungszentrum OPTIMAS, 67663 Kaiserslautern, Germany

The determination of spin and orbital magnetic moments from the free atom to the bulk phase is an intriguing challenge for nanoscience, since most magnetic recording materials are based on nanostructures. We present temperature-dependent X-ray magnetic circular dichroism (XMCD) measurements of free Co-clusters (N=8-22) from which the intrinsic spin and orbital magnetic moments have been deduced [1]. An exceptionally strong enhancement of the orbital moment is verified for free magnetic clusters which is 4-6 times larger than the bulk value. Our temperature-dependent measurements reveal that the spin orientation along the external magnetic field is nearly saturated at ca. 20 K and 7 T while the orbital orientation is clearly not. The comparison of the magnetic moments as deduced from XMCD and previous Stern-Gerlach measurements might help to reconcile divergent results of the total magnetic moments of small Co-clusters published earlier. We present an outlook towards other transition metal clusters.

References: [1] S.Peredkov et al., PRL 107, 233401 (2011)