Exchange coupling and magnetic anisotropy at Fe/FePt interfaces

C. J. Aas, P. J. Hasnip, R. Cuadrado, E. M. Plotnikova, L. Szunyogh, L. Udvardi, R. W. Chantrell

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

We perform fully relativistic first-principles calculations of the exchange interactions and the magnetocrystalline anisotropy energy (MAE) in an Fe/FePt/Fe sandwich system in order to elucidate how the presence of Fe/FePt (soft/hard magnetic) interfaces impacts on the magnetic properties of Fe/FePt/Fe multilayers. Throughout our study we make comparisons between a geometrically unrelaxed system and a geometrically relaxed system. We observe that the Fe layer at the Fe/FePt interface plays a crucial role inasmuch as its (isotropic) exchange coupling to the soft (Fe) phase of the system is substantially reduced. Moreover, this interfacial Fe layer has a substantial impact on the MAE of the system. We show that the MAE of the FePt slab, including the contribution from the Fe/FePt interface, is dominated by anisotropic intersite exchange interactions. Our calculations indicate that the change in the MAE of the FePt slab with respect to the corresponding bulk value is negative, i.e., the presence of Fe/FePt interfaces appears to reduce the perpendicular MAE of the Fe/FePt/Fe system. However, for the relaxed system, this reduction is marginal. It is also shown that the relaxed system exhibits a reduced interfacial exchange. Using a simple linear chain model, we demonstrate that the reduced exchange leads to a discontinuity in the magnetization structure at the interface.

Original languageEnglish
Article number174409
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume88
Issue number17
DOIs
Publication statusPublished - Nov 13 2013

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Magnetocrystalline anisotropy
Exchange coupling
Magnetic anisotropy
anisotropy
Exchange interactions
slabs
energy
Magnetization
Magnetic properties
discontinuity
Multilayers
interactions
magnetic properties
magnetization

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

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Exchange coupling and magnetic anisotropy at Fe/FePt interfaces. / Aas, C. J.; Hasnip, P. J.; Cuadrado, R.; Plotnikova, E. M.; Szunyogh, L.; Udvardi, L.; Chantrell, R. W.

In: Physical Review B - Condensed Matter and Materials Physics, Vol. 88, No. 17, 174409, 13.11.2013.

Research output: Contribution to journalArticle

Aas, C. J. ; Hasnip, P. J. ; Cuadrado, R. ; Plotnikova, E. M. ; Szunyogh, L. ; Udvardi, L. ; Chantrell, R. W. / Exchange coupling and magnetic anisotropy at Fe/FePt interfaces. In: Physical Review B - Condensed Matter and Materials Physics. 2013 ; Vol. 88, No. 17.
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