Interlayer coupling in Tb/Fe bilayers and Tb/Au/Fe trilayers with sharp or rough interface

Bilayer films Fe/Tb (Tb on Fe) having sharp and Tb/Fe (Fe on Tb) having rough interface were prepared by molecular beam epitaxy to study interlayer magnetic coupling. Magnetic properties of these bilayers were characterized ex situ using ferromagnetic resonance (FMR), polar magneto-optical Kerr effect and SQUID magnetometer. The resulting perpendicular magnetic anisotropy (PMA) is discussed as an effect of interlayer magnetic coupling. PMA was observed in rough as well as in sharp interfaces and the anisotropy energies were estimated. When a monolayer of Au was interposed at the interface of both kinds, PMA was observed to disappear and the overall magnetic moment increased. It was also shown that in ultrathin films demagnetization factor depends on the substrate roughness and should be considered in the FMR data. Bilayer films Fe/Tb (Tb on Fe) having a sharp interface and Tb/Fe (Fe on Tb) having a rough interface are prepared by molecular beam epitaxy to study the interlayer magnetic coupling. The magnetic properties of these bilayers are characterized ex situ using ferromagnetic resonance (FMR). The polar magnetooptical Kerr effect, and a SQUID magnetometer. The resulting perpendicular magnetic anisotropy (PMA) is discussed as an effect of the interlayer magnetic coupling. PMA is observed at rough as well as at sharp interfaces, and the anisotropy energies are estimated. When a monolayer of Au is interposed at either kind of interface, the PMA is observed to disappear and the overall magnetic moment increases. It is also shown that in ultrathin films the demagnetizing factor depends on the substrate roughness and should be taken into account in the FMR data