The magneto-optical Kerr effect of Fe/Au-Cu and Fe/Al-Cu bilayers

In the magneto-optical polar Kerr rotation spectra of Fe/Au-Cu bilayers made by vacuum evaporation with the thickness of Fe layer less than the light penetration depth, a broad enhancement of the Kerr rotation spectra occurs near the absorption edge in the reflectivity spectra of Au-Cu alloys and shifts towards the longer wavelength side when the content of Cu in the Au-Cu reflector increases. For Fe/Al-Cu bilayers made by rf magnetron sputtering with a small content of Al in the Al-Cu reflector a peak occurs in its Kerr rotation spectrum. When the content of Al becomes larger the Kerr rotation increases with the decrease of wavelength monotonically and an enhancement occurs in the short wavelength region.