Oscillatory interlayer coupling in Fe/Mn/Fe trilayers

Abstract

Fe/Mn/Fe wedged-shape sandwiches were prepared by molecular beam epitaxy under optimal conditions. The interlayer coupling measured by magneto-optic Kerr effect is very strong for thin Mn layers. The canted angle between the magnetization vectors of the two magnetic layers in remanence increases gradually from 0\ifmmode^\circ\else\textdegree\fi{} to about 180\ifmmode^\circ\else\textdegree\fi{} and then gradually reduces to 90\ifmmode^\circ\else\textdegree\fi{} for Mn thicknesses from 0.62 to 1.2 nm. For Mn layer thicknesses in the range between 1.2 and 2.45 nm, the interlayer coupling is always 90\ifmmode^\circ\else\textdegree\fi{} coupling, but its strength oscillates with a short period of about 2 Mn monolayers. The above coupling phenomenon can be well described by the proximity magnetism model.