MAGNETO-OPTICAL KERR EFFECT IN A PARAMAGNETIC OVERLAYER ON A FERROMAGNETIC SUBSTRATE - A SPIN-POLARIZED QUANTUM SIZE EFFECT

摘要

The magneto-optical properties of a paramagnetic overlayer on a ferromagnetic substrate are discussed. The spin-dependent electron confinement in the overlayer due to the ferromagnetic substrate gives rise to spin-polarized quantum size effects in the paramagnetic overlayer. It is shown that the latter induce a nonvanishing Kern effect in the overlayer, which oscillates with overlayer thickness. The mechanism of Kerr effect in this case is rather different from the one of Kerr effect in a bulk ferromagnet. The periods of oscillations are related to the bulk band structure of the overlayer material. The theory is applied to the case of Au/Fe(001); the calculated period of Kerr effect oscillations versus Au thickness is found to vary in a dramatic manner with photon energy in the visible-UV range. [References: 25]