Regensburg 2004 – wissenschaftliches Programm

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SYXM: X-RAY Magneto-Optics

SYXM 1: X-Ray Magneto-Optics

SYXM 1.3: Hauptvortrag

Dienstag, 9. März 2004, 15:30–16:00, H1

X-ray magneto-optics of lanthanide materials: principles and applications — •José Emilio Prieto, Franziskus Heigl, Oleg Krupin, Kristian Döbrich, Günter Kaindl, and Kai Starke — Institut für Experimentalphysik, Freie Universität Berlin, Germany

Lanthanides are frequently employed in technical magnetic systems to achieve high anisotropies. In contrast to transition metals, magnetic moments are carried mainly by the localized 4f electrons, and their correlation energies give rise to rich multiplet structures in optical excitation spectra whenever the 4f shell is involved. This results in strong magnetic dichroism in x-ray absorption and, due to the connection between real and imaginary parts of the refractive index, also in large magneto-optical effects in resonant reflectivity [1].

Soft x-ray magneto-optics is well suited to study magnetization reversal processes in external magnetic fields. Yet in order to obtain quantitative information on the magnetization from reflectivity data, comparison with model calculations is required. Here we report on recent progress in determining the soft x-ray magneto-optical constants of lanthanides [2,3] and show examples of applying specular resonant reflectivity to analyse the magnetization reversal of thin films and exchange-coupled trilayer systems in an element specific way.

[1] K. Starke, F. Heigl, A. Vollmer, M. Weiss, G. Reichardt, and G. Kaindl, Phys. Rev. Lett. 86, 3415 (2001)

[2] J. E. Prieto, F. Heigl, O. Krupin, G. Kaindl, and K. Starke, Phys. Rev. B 66, 172408 (2002)

[3] J. E. Prieto, F. Heigl, O. Krupin, G. Kaindl, and K. Starke, Phys. Rev. B 68, 134453 (2003)