The fluorescence yield under the Bragg reflection of right and left circular polarized radiation with a wavelength in the vicinity of the FeL 2, 3 absorption edges from the periodic multilayer [Fe(1.5 nm)/V(1.5 nm)]10 that is characterized by the antiferromagnetic interlayer exchange coupling has been theoretically analyzed in L-MOKE geometry. It has been shown that the largest polarization asymmetry of reflectivity takes place at the “magnetic” Bragg reflection, which appears due to the doubling of the magnetic period. The expected occurrence of the dichronic signal in the fluorescence yield by its selective excitation in the layers with the same magnetization direction was confirmed, but the effect is suppressed by the specific behaviour of the standing waves in the strongly absorbing multilayers where the standing wave antinodes are situated in layers with low absorption.

The general matrix theory of the photoelectron/fluorescence excitation in anisotropic multilayer films at the total reflection condition of X-rays has been developed. In a particular case the theory has been applied to explain the oscillation structure of L(2,3) XANES spectra for a SiO(2)/Si/SiO(2)/c-Si sample in the pre-edge region which has been observed by a sample current technique at glancing angles of synchrotron radiation. Remarkably the phase of the oscillations is reversed by a ∼2° angle variation. The observed spectral features are found to be a consequence of waveguide mode creation in the middle layer of strained Si, which changes the radiation field amplitude in the top SiO(2) layer. The fit of the data required the correction of the optical constants for Si and SiO(2) near the Si L(2,3)-edges.

The X-ray resonant magnetic scattering (XRMS) method allows for the determination of optical constants including magnetic corrections, which are significant near the atomic X-ray absorption edges, by the shift of the Bragg angle of the reflection from periodic multilayers. Recently, Valvidares et al. [Phys. Rev. B 78 , 064406 (2008)] revealed significant differences in the shape of “magnetic” Bragg reflection peaks from a [Co 73 Si 27 (50 Å)/Si(30 Å)] 10 film for two opposite states of antiferromagnetic interlayer ordering. Valvidares et al. assumed that these features can be explained by the presence of the reflection-induced magnetic resonance correction. We have demonstrated that such corrections in the case of antiferromagnetic structures do not lead to a shift of the Bragg peak, but the shape of magnetic peaks is explained by the interference of the magnetic and nonmagnetic reflection amplitudes.

X-ray reflectivity near the absorption edges should take into account the anisotropy of X-ray susceptibility in the presence of magnetic interaction. In this paper different approaches used to calculate X-ray reflectivity have been considered. It has been shown that in the case of L-MOKE geometry at grazing angles calculations are radically simplified if performed in terms of the circular polarized eigen waves. We reveal that approximations, used by N. Ishimatsu et.al. (Phys. Rev. B 60, 9596 (1999)) for description of the eigen vectors of the radiation field, are applicable at grazing angles only. Approximate expressions for the integral propagation matrices, obtained by E. Kravtsov et.al. (Phys. Rev. B79, 1334438 (2009)), are valid for the whole angular range, however, they do not describe some effects in special cases (i.e. transversal magneto-optical Kerr-effect).

The reflectometry curves of an Nb(4 nm)/YFe2(40 nm, 〈110〉)/Fe(1.5 nm)/Nb(50 nm) sample measured in the synchrotron radiation of right- and left-handed circular polarization for a set of wavelengths near the Y L 2,3 absorption edges have been used to determine the energy dependences of the component magnitudes for the X-ray susceptibility tensor of YFe2 near the yttrium absorption edges, including off-diagonal magnetic additives. Our result is in good agreement with the normalized experimental absorption and circular dichroism spectra and their Kramers-Kronig transformations.

An analysis of the influence of standing waves on the angular dependencies of the fluorescent yield from an ultrathin iron layer buried inside a multilayer structure of Nb(50 nm)/Fe(3.9 nm)/[Si/Mo(6.77 nm)] 40 /SiO 2 is presented. These angular dependencies of reflectivity and Fe K α -fluorescence yield were measured at the Station for high-precision X-ray optics (HPXO) of the Kurchatov Center for Synchrotron Radiation and Nanotechnology. The measured data was analyzed with the help of our FLUO software package. As a result of the complex treatment of reflectivity and Fe fluorescent yield data, the depth profile for iron atomic density was restored.

Element-specific measurements of the fluorescent radiation combined with measurements of the reflectivity curves have been performed for a Zr(10 nm)/[Fe(1.6 nm)/Cr(1.7 nm)]26/Cr(50 nm)/glass sample with the use of a new experimental setup created at the Institute for Analytical Instrumentation. The experimental data have been processed using a FLUO simulation program package implemented in the Visual C++ environment. The Zr, Fe, Cr, and Sn depth profiles have been reconstructed via coprocessing of reflectivity and fluorescence yield curves that were measured for each of these elements.