No abstract

The existence of the x-ray magneto-optical Voigt effect is demonstrated. By means of polarization analysis the Voigt rotation and ellipticity of linearly polarized synchrotron radiation are measured at the Co L3 edge upon transmission through an amorphous Co film. The observed x-ray Voigt rotation is about 7.5 degrees /microm. On the basis of ab initio calculations it is shown that the x-ray Voigt effect follows sensitively the amount of spin polarization of the 2p core states. Therefore it provides a unique measure of the spin splitting of the core states.

No abstract

A systematic study of the specular reflectivity using circularly and linearly polarized radiation on magnetic materials is presented. Within a frame work based on the complete reflection matrix and the Stokes parameter formalism, the reflectance is modeled as a function of the polarization state of the incoming light for the longitudinal and the transversal magnetization. The nonmagnetic reflection coefficients and their individual magnetic contributions are determined from resonant magnetic reflectivity experiments of polarized soft x rays across the Fe-2p absorption edge on a ferromagnetic Fe/C multilayer. Exploiting tunable undulator radiation the absolute reflectance is investigated as a function of the degree of circular or linear polarization, photon energy, angle of incidence, and magnetic-field direction. As predicted by the developed formalism the corresponding magnetic asymmetry parameters depend nonlinearly on the degree of polarization at large angles of incidence due to the influence of the polarizing power of the sample. In the longitudinal geometry using circularly polarized light, the magnetic contribution is directly related to the magnetic contribution of the optical constants, which have independently been determined by Faraday measurements on an identical transmission sample.

No abstract