6533b7d1fe1ef96bd125d4ce

RESEARCH PRODUCT

Hard x-ray photoelectron spectroscopy of buried Heusler compounds

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This work reports on high energy photoelectron spectroscopy from the valence band of buried Heusler thin films (Co2MnSi and Co2FeAl0.5Si0.5) excited by photons of about 6?keV energy. The measurements were performed on thin films covered by MgO and SiOx with different thicknesses from 1 to 20?nm of the insulating layer and additional AlOx or Ru protective layers. It is shown that the insulating layer does not affect the high energy spectra of the Heusler compound close to the Fermi energy. The high resolution measurements of the valence band close to the Fermi energy indicate a very large electron mean free path of the electrons through the insulating layer. The spectra of the buried thin films agree well with previous measurements from bulk samples. The valence band spectra of the two different Heusler compounds exhibit clear differences in the low lying s bands as well as close to the Fermi energy.