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Schlagwörter:
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Zusammenfassung:
Using circularly polarised radiation and a combination of bulk-sensitive
hard x-ray photoelectron spectroscopy and x-ray-absorption spectroscopy
(XAS) we studied the electronic and magnetic structure of epitaxial
Mn1.8Co1.2Ga thin films. Spin-resolved Bloch spectral functions, density
of states as well as charge and magnetisation densities were
investigated by a first-principles analysis of full potential, fully
relativistic Korringa-Kohn-Rostoker calculations of the electronic
structure. The valence states were experimentally investigated by using
linear dichroism in the angular distribution and comparing the results
to spin-resolved densities of states. The linear dichroism in the
valence band enabled a symmetry analysis of the contributing states. The
spectra were in good agreement with the theoretical partial density of
states. The element-specific, spin-resolved, unoccupied densities of
states for Co and Mn were analysed by using XAS and x-ray magnetic
circular dichroism (XMCD) at the L-3,L-2 edges. The spectra were
influenced by strong correlation effects. XMCD was used to extract the
site-resolved magnetic moments. The experimental values of m(Mn) = 0.7
mu(B) and m(Co) = 1.05 mu(B) agree very well with the calculated
magnetic moments. Magnetic circular dichroism in angle-resolved
photoelectron spectroscopy at the Mn and Co 2p core level exhibited a
pronounced magnetic dichroism and confirmed the localised character of
the Mn d valence states.
