Lukiienko I. Peculiarities of the Kerr and Faraday magneto-optical effects in multilayer nanofilms Co/Cu (111)

The dissertation presents the results of experimental study of the multilayer “ferromagnetic/non-magnetic metal” [Co(111)/Cu(111)]20 nanofilms, which have the constant thickness of ferromagnetic layers dCo = 0,8 nm and the variable thickness of non-magnetic layers dCu = 0,6 .. 2,0 nm. The influence of the thickness of non-magnetic layers has been studied on magneto-optical properties of the nanofilms, in which the Ruderman-Kittel-Kesuya-Yosida exchange coupling exists between ferromagnetic layers. It has been shown experimentally that the increase of magneto-optically inactive Cu layers causes the monotonic enhancement of the Faraday rotation in the films, which is described by the effective medium approximation and connected with increasing the contribution of multiple light scattering on interfaces to the magneto-optical effect. The enhancement of the magneto-optical longitudinal Kerr effect has been revealed, which correlates with the exchange coupling between ferromagnetic layers. The essential contribution of Co/Cu interfaces is suggested as the main reason of the observed enhancement. Correlation between fragmentation of ferromagnetic layers and exchange coupling between them has been revealed and it is shown that sizes of superparamagnetic Co clusters are considerably smaller in the films with antiferromagnetic exchange coupling.