Physical Review B (Condensed Matter and Materials Physics) 
Print Issue of 1 March 2001 

Phys. Rev. B 63, 104407 (2001) (15 pages)

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Fe /Cr interface magnetism: Correlation between hyperfine fields and magnetic moments

      V. M. Uzdin 
      ICAPE, Saint-Petersburg State University, V.O. 14 Linia 29, 199178, St. Petersburg, Russia 

      W. Keune, H. Schrör, and M. Walterfang 
      Laboratorium für Angewandte Physik, Gerhard-Mercator-Universität Duisburg, Lotharstr. 65, D-47048 Duisburg, Germany 

(Received 28 February 2000; published 14 February 2001) 

The magnetic hyperfine field (hff) in epitaxial Fe/Cr(001) superlattices on Mg(001) with different thicknesses of interfacial 57Fe probe layers was measured by Mössbauer spectroscopy.
Self-consistent calculations of the Fe and Cr atomic magnetic moments in the interface region were performed within the periodic Anderson model for the same superlattice structure. Different kinds
of interface roughness/interdiffusion were modeled using special algorithms. For every kind of interface roughness the distribution of local magnetic moments among the Fe atoms with a given number
of nearest and next-nearest Cr neighbors was calculated. We obtain a strong correlation between the experimental hff and calculated local Fe magnetic moments. Peak positions in the hff distribution
and correlated positions of maxima in the distribution function for local magnetic moments are observed to be stable relative to changes in the alloylike interface roughness. We found that the hff of ~20
T must correspond to interdiffused Fe atoms inside the Cr spacer layers a few atomic layers away from the ideal interface, contrary to earlier interpretations of Fe atoms at the atomically "flat"
interface. As a measure of the Fe-Cr interface roughness on an atomic scale our results suggest an enhanced hff in the second Fe layer below the ideal interface in case of atomically smooth
interfaces with large flat terraces. ©2001 The American Physical Society 

URL: http://link.aps.org/abstract/PRB/v63/e104407 
DOI: 10.1103/PhysRevB.63.104407 
PACS: 75.70.Cn, 76.80.+y, 73.40.Jn