Published online by Cambridge University Press: 01 October 2002
We present experimental results on longitudinal magneto-optic Kerr effect
in composite systems based on thin Fe layers associated with amorphous
alumina (Al2O3). [Al2O3/Fe]m-samples ($m=1,\,2$) have been prepared by rf
magnetron sputtering onto Si(100) substrate. We have investigated the
effect of the Al2O3 and Fe thicknesses on the Kerr rotation. The geometry
of the multilayers is predicted theoretically by using deduced experimental
magneto-optical constants. It will be shown how large Kerr rotation values
can be obtained by adjusting sample parameters. For instance, a Kerr
rotation close to 7° has been observed from an Al2O3/Fe/Al2O3/Fe/Si
multilayer. The reflectivity and the figure of merit are discussed as a
function of the Al2O3 thickness.