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Long and Short Range Oscillatory Exchange Coupling in Fe/Cu and Co/Cu Magnetic Multilayers

Published online by Cambridge University Press:  26 February 2011

F. Herman ,
J. Sticht  and
M. Van Schilfgaarde
F. Herman
Affiliation:
IBM Almaden Research Center San Jose, CA 95120-6099, USA
J. Sticht
Affiliation:
Technische Hochschule, D-6100 Darmstadt, Germany
M. Van Schilfgaarde
Affiliation:
SRI International, Menlo Park, CA 94025, USA
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Abstract

By carrying out accurate first-principles superlattice calculations, we determined the exchange coupling in bcc Fe/Cu and fcc Co/Cu multilayers as a function of the Cu spacer thickness. The fact that we can obtain long-range oscillatory coupling directly from first principles suggests that our theoretical model includes the underlying physical mechanism, and that such coupling is indeed a band structure effect. The exchange coupling depends on the interfacial orientation as well as on the Cu spacer thickness. In bcc [001] Fe/Cu, fcc [001] Co/Cu, and fcc [110] Co/Cu, the coupling has both long and short-range oscillatory components, while in fcc [111] Co/Cu, the long-range component dominates. Using a simplified model for the Fermi surface of the Cu spacer, we can relate the short-range oscillations to electronic transitions across the Fermi sphere, and the long-range oscillations to electronic transitions between spheres in adjacent zones in extended k-space, i.e., to interzonal transitions.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 231: Symposium S – Magnetic Surfaces, Thin Films and Multilayers , 1991 , 195
Copyright
Copyright © Materials Research Society 1992

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References

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