Hong-Yan Zhang

Magneto-optics in layered and multilayered films

Abstract The magneto-optical Kerr rotation in various bilayer, trilayer and multilayer films are studied experimentally and theoretically. In bilayers and trilayers the enhancement of Kerr rotation by a factor of two to five based on the reduction of effective optical constants has been achieved with a reasonable reflectivity. The enhancement can be realized in the whole wavelength region, from near IR to near UV. In Fe/Pd and FeSi/Cu multilayer films an additional magneto-optical activity related to the exchange polarization of Pd and Cu layers is observed. Multilayer films with broad opportunities for reducing effective optical constants and creating additional magneto-optical activities are demonstrated to be a promising area for finding new magneto-optical materials.

The magneto‐optical Kerr effect of multilayers Fe/Pt and Co/Pt

In this communication, the magneto‐optical polar Kerr rotation spectra of multilayers Fe/Pt and Co/Pt are calculated based on two different assumptions. First, the spin polarization of the Pt layer is assumed to be negligible. The calculated results for Fe/Pt and Co/Pt multilayers with dCo(Fe)/dPt=1 showed the magneto‐optical Kerr rotation in the region from 300 to 800 nm increased with increasing modulation wavelength, which is opposite to experimental results. Second, the Pt layer is assumed to be polarized and has a direct contribution to Kerr rotation in the multilayers. The results agree with experiments qualitatively. It is found that the spin polarization of the Pt layer increases with decreasing Pt layer thickness.

MOKE enhancement of Fe/ZnSe multilayers and bilayers

Abstract The magneto-optical polar Kerr rotation and reflectivity spectra of Fe/ZnSe multilayers and bilayers prepared by vacuum evaporation have been studied. For bilayers the maximum Kerr rotation at 700 nm in a magnetic field of 7000 Oe is about 1.4° with the reflectivity being larger than 50%. On the short-wavelength with a sign reversal of the Kerr rotation appears, which is considered as being due to the influence of the optical constant of the ZnSe layer and the thickness of the Fe layers. For multilayers the Kerr rotation increases with increasing wavelengths on the long-wavelength side and does not change very much on the short-wavelength side. The influence of the non-magnetic ZnSe layers on the MOKE spectra is discussed.

Magnetic properties and MOKE spectra of Fe/Pd CMF☆

Abstract Fe/Pd compositionally modulated films (CMFs) of various thicknesses prepared by vacuum evaporation were studied by VSM, FMR and MOKE spectra measurements. The room temperature magnetization of Fe layers and the polarization of Pd layers are deduced. At short wavelength the Kerr rotation of Fe/Pd CMFs increases with increasing polarization of the Pd layers. At long wavelengths the Kerr rotation, which is mainly contributed by the Fe layers, increases with Fe content.