Modulation length dependence of magneto-optical Kerr effect in Fe/Cu multilayer films

A relation between modulation length and wavelength dependence of polar magneto-optical Kerr rotation θKin Fe/Cu compositionally modulated multilayer films has been investigated. A new peak of θKappears at about λ = 560nm, corresponding to the absorption edge of Cu metal, and becomes large with the increase of modulation length D. The θKpeak moves towards longer wavelength side with increasing thickness ratio of Fe/Cu. There are optimum values of Fe/Cu thickness ratio and modulation length for the enhancement of θK.