Dresden 2006 – wissenschaftliches Programm
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MA: Magnetismus
MA 14: Magnetic Thin Films II
MA 14.8: Vortrag
Dienstag, 28. März 2006, 12:00–12:15, HSZ 03
Layer-resolved magnetization of a Heisenberg film from magnetic Laue profiles — •Enrico Schierle1, Eugen Weschke1, Alexander Gottberg1, Günter Kaindl1, Walter Söllinger2, and Gunther Springholz2 — 1Institut für Experimentalphysik, Freie Universität Berlin, D-14195 Berlin, Germany — 2Institut für Halbleiterphysik, Johannes Kepler University, A-4040 Linz, Austria
Layer-dependent properties of magnetic films have been the subject of extensive theoretical studies since the work of Binder and Hohenberg [1]. Using resonant magnetic soft x-ray scattering, we studied the temperature-dependent magnetization of the individual layers in thin (111) films of the prototypical Heisenberg antiferromagnet EuTe [2]. The high magnetic sensitivity at the lanthanide M5 resonance [3] can be exploited and for the x-ray wavelength of the resonance, the magnetic signal appears exactly at the Brewster angle, which allows to measure magnetic scattering virtually free of charge background. Thus, the magnetic Laue profile of a 20-layer thick film can be measured with unprecedented quality over a large range of momentum transfer. The real-space magnetization profile across the film is obtained from the corresponding Patterson function, yielding the temperature-dependent magnetization of each individual layer. The results are in agreement with Monte-Carlo calculations that show reduced magnetization and enhanced critical exponents for the temperature dependence in the surface region.
[1] K. Binder and P.C. Hohenberg, Phys. Rev. B 9, 2194 (2004).
[2] H. Kepa et al., Phys. Rev. B 68, 24419 (2003).
[3] E. Weschke et al., Phys. Rev. Lett., 93 (157204), 2004.