TY - JOUR
T1 - Exchange coupling and magnetic anisotropy at Fe/FePt interfaces
AU - Aas, C.J.
AU - Hasnip, P.J.
AU - Cuadrado, R.
AU - Plotnikova, E.M.
AU - Szunyogh, L.
AU - Udvardi, L.
AU - Chantrell, R.W.
PY - 2013/11/13
Y1 - 2013/11/13
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=84888338988&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.88.174409
DO - 10.1103/PhysRevB.88.174409
M3 - Article
AN - SCOPUS:84888338988
SN - 1098-0121
VL - 88
JO - Physical Review B: Condensed Matter and Materials Physics
JF - Physical Review B: Condensed Matter and Materials Physics
IS - 17
M1 - 174409
ER -