Regensburg 2004 – scientific programme
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SYXM: X-RAY Magneto-Optics
SYXM 1: X-Ray Magneto-Optics
SYXM 1.2: Invited Talk
Tuesday, March 9, 2004, 15:00–15:30, H1
Magnetization profiling by resonant magnetic x-ray reflectometry — •G. Schütz, J. Geissler, and E. Goering — Max-Planck Institut für Metallforschung, Stuttgart
The asymmetry ratio of resonant magnetic x-ray reflection shows a strong
variation with the angle of incidence. The maximum value of the complex
magnetic reflection profile is in the order of the corresponding XMCD signal, from
which the main magnetic contribution of the absorptive scattering amplitude can
be deduced while the dispersive part is calculated via Kramers Kronig relations.
If the correlation of the XMCD effect to the atomic magnetic moment is known,
the magnetization depth profile can be deduced by an artificial slicing method
utilizing the Parratt algorithm [1]. For hard x-rays (e.g. L2,3 edges
for 4f or 5d
elements) with scattering vector of less than one degree cross and scalar
products can be simplified. The application of this theoretical model is much
more complicated for soft x-rays and related to large scattering angles.
However, this energy range covers the L2,3 edges of 3d transition elements,
which
exhibit large asymmetry ratios amounting to 50 % [2].
The potential of this method especially for technical relevant GMR/TMR
systems, whose magneto-electric properties can strongly depend on the interphase
morphogy, is demonstrated for a Pt/Co/Cu trilayer. For this composition it was
possible to determine the variation of the magnetic interface depth profile for
each layer reaching an accuracy of about 10 % for Pt and Co with a depth
resolution up to 0.1 nm. Even for the Cu component an estimation of the induced
magnetic moment at the Co-Cu interface is possible [3].
[1] J. Geissler et al., Phys. Rev. B 65, 020405 (2001)
[2] J. Geissler et al., Z. Metallkd. 93, 946 (2002)
[3] E. Goering et al., in preparation