Dresden 2006 – scientific programme
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MA: Magnetismus
MA 8: Surface Magnetism
MA 8.8: Talk
Monday, March 27, 2006, 16:45–17:00, HSZ 103
Structural and electronic properties of pseudomorphic Cr1−xFex-submonolayers on W(110) — •T. Methfessel and H.J. Elmers — Johannes Gutenberg-Universität Mainz, Institut für Physik, Staudingerweg 7, D-55099 Mainz
Submonolayer coverages of Cr1−xFex-random-alloys have been investigated using low energy electron diffraction (LEED), scanning tunneling spectroscopy (STS) and Kerr-magnetometry. The Curie-temperatures of the alloys strongly depend on the composition and vary surprisingly similar to the bulk behavior. We observe a maximum of TC at x=0.95.
Characteristic peaks in the STS spectra, indicating unoccupied surface states, show up at constant energy values independent on the composition. Assuming a rigid-band-model, the Fermi-energy should decrease with respect to the 3d-states for increasing Cr concentration. But this behavior was not observed. Thus the rigid-band model fails. However, with the assumption that the 4s-states are shifted above EF the observation of a nearly composition-independent electronic structure can be tentatively explained.
We compare the results obtained here with previous results for FexMn1−x/W(110) submonolayers [1].
[1] M. Pratzer and H.J. Elmers, Phys.Rev.B 69,134418(2004).