Regensburg 2013 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 25: Magnetic Heusler Compounds

MA 25.6: Vortrag

Mittwoch, 13. März 2013, 10:45–11:00, H10

Electronic properties of Heusler alloys investigated by X-ray magnetic linear dichroism — •Mirko Emmel¹, Ingo Krug², Daniel Gottlob², Alexey Alfonsov³, Sabine Wurmehl³, Hans-Joachim Elmers¹, and Gerhard Jakob¹ — ¹Institut für Physik, Johannes Gutenberg-Universität Mainz, Germany — ²Forschungszentrum Jülich, Germany — ³Leibniz-Institut für Festkörper- und Werkstoffforschung IFW-Dresden, Dresden, Germany

Theoretical calculations have indicated that XMLD spectra are much more sensitive to changes of the electronic structure compared to XMCD spectra [1]. Thus several thin films of Co₂FeSi have been prepared on a MgO(100) substrate to verify existing theoretical predictions. The films were prepared by DC magnetron sputtering at varying deposition temperatures to achieve different degrees of atomic order within the films. After a capping layer of Al or Cr was deposited to prevent oxidation, the samples were analyzed by NMR measurements at IFW Dresden. The XMLD measurements were performed using the XAS apparatus installed at the UE56-1/SGM beamline (Jülich). The results show clear and uniform features. However, the samples capped with Al show similar behavior to results for Co₂FeAl_0.5Si_0.5. Thus it is presumed that Al atoms are being implanted into the subsurface of Co₂FeSi, which makes Cr the capping layer of choice. Finally we see a change of the magnitude within the XMLD spectra depending on the local atomic order of the film.

We acknowlodge support by DFG research group ASPIMATT.

[1] M. Kallmayer et al., Phy. Rev. B 84, 054448 (2011)