Change of magneto-optical Kerr rotation due to interlayer thickness in magnetically coupled films with noble-metal wedge

An intensity oscillation of the saturation polar Kerr rotation φK due to interlayer thickness d was observed in Fe(5 Å)/Au(d Å)/Fe(5 Å)(100) and Fe(6 Å)/Au(d Å)/Fe(6 Å)(100) sandwiched films. The periods of the oscillation are about 7–8 and 5–6 monolayers of Au thickness, respectively. The oscillation of φK can be observed only in the photon energy range 2.5–3.8 eV for Fe(6 Å)/Au(d Å)Fe(6 Å). These phenomena are considered to be closely related to a formation of spin-polarized quantum-well states of the minority Δ1 band in the Au layer sandwiched with two Fe barrier layers. The φK peak positions and oscillation period do not correspond exactly to those of the change in the in-plane saturation field Hs.