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A double periodic Fe1/Au/Fe2/Au multilayer with different Fe thicknesses was epitaxially grown on the MgO(001) substrate to investigate the magnetic structure of the Au spin polarization in an antiparallel alignment state of the Fe magnetizations. The establishment of the antiparallel alignment state at zero applied field was confirmed from the comparison of the magnetization curve measurement and simulation in the applied field along the [110] direction of the MgO substrate. Existence of the Au spin polarization orthogonal to the applied magnetic field was confirmed with resonant X-ray magnetic scattering (RXMS) measurements near the Au L3 absorption edge. Analysis of the RXMS pattern indicated that the magnetic depth profile of the spin polarization in the interior region of the Au layer was approximated to a square-wave shape, which suggests a ferromagnetic nature of the Au spin polarization sandwiched by the Fe layers.

It is known that spin polarization induced in the Au layers of Fe/Au multilayers which show interlayer exchange coupling consists of an interface-concentrated component and a uniformly extended interior component. To investigate the origin of the interior component, magnetic depth profiles of spin polarization induced in the Au layers of Fe (15 A)/Au (50 A) bilayer and Fe (15 A)/Au (50 A)/Fe (15 A) trilayer films were investigated with resonant X-ray magnetic reflectivity (RXMR) measurements at the Au L3 absorption edge. After the determination of charge structures, the spin attenuation length for the interior component of the bilayer sample was evaluated to be longer than 15 A from the analysis of the RXMR pattern. The RXMR pattern of the trilayer sample was not sufficiently reproduced if the magnetic structure of the trilayer sample was assumed to be a simple sum of the magnetic structure obtained from the bilayer sample. Results were discussed based on the quantum well model.

Interface magnetism was investigated for Ir atoms in Mn73Ir27/Co70Fe30 and Mn77Ir23/Fe bilayers which showed an exchange bias effect. Scattering angle and X-ray energy dependent resonant X-ray magnetic scattering patterns were measured at a small angle region around the Ir L3 absorption edge to determine the induced magnetic structure of the Ir 5d magnetic moment. It is found that the induced Ir magnetic moment which follows applied field reversal is concentrated at the first atomic layer of the antiferromagnetic MnIr layer for both MnIr/CoFe and MnIr/Fe samples. The direction of the Ir moment is parallel to the magnetic moment of the ferromagnetic layer independent of the composition of the ferromagnetic layer. This behavior is different from that reported on the uncompensated 3d magnetic moment of Mn atoms. The average size of the Ir moment in the MnIr/CoFe bilayer is estimated to be about 1.4 times larger than that in the MnIr/Fe bilayer. These results are consistent with a first-principles band calcul...

Spin polarization of 5d conduction electrons induced in the Au layers of antiferromagnetically coupled Fe/Au metallic superlattice was investigated by resonant X-ray magnetic diffraction at the Au L3 absorption edge. Superlattice reflections around the Au 002 Bragg peak were measured in the magnetic saturation state with circularly polarized synchrotron radiation X-rays of 11921 eV. The magnetic diffraction profile was extracted with the combination of helicity switching and reversing the direction of magnetic field applied along the line of intersection between the film surface and the scattering plane. The depth distribution of resonant magnetic scattering length in the Au layers was estimated from the magnetic diffraction profile. Both resonant magnetic diffraction from the Au layer and non-resonant magnetic diffraction from the Fe layer were considered in the analysis. We demonstrated that the depth distribution of the Au magnetic scattering length was expressed with sum of the interface-concentrated ...

By applying our new experimental technique of X-ray absorption spectroscopy (XAS) and its X-ray magnetic circular dichroism (XMCD) in the soft-X-ray region under high pulsed magnetic fields of up to 21.3 T, we measured the XAS and XMCD spectra at the Eu M 4,5 edges of EuNi 2 (Si 0.18 Ge 0.82 ) 2 . The measured spectra are analyzed by taking into account the atomic multiplet structures to clarify the mixed valence properties, which are caused by the hybridization between Eu 2+ and Eu 3+ configurations. We obtain the field dependence of the average valence number from the XAS spectra and that of the magnetizations of Eu 2+ and Eu 3+ components separately using the spin and orbital sum rules from the XMCD spectra. These results are in good agreement with theoretical ones calculated with a modified single-impurity Anderson model. The present study reveals the key to solving a puzzling problem that was posed in previous XAS and XMCD experiments in the hard-X-ray region.

X-ray energy dependence of the resonant X-ray magnetic scattering (RXMS) intensity was measured at several magnetic diffraction angles in the small angle region in order to investigate the magnetic structure of the Au layer induced in the Fe/Au(001) multilayer with antiferromagnetic interlayer coupling. The observed spectra are reproduced well using the depth modulation of the resonant magnetic scattering length previously determined from the angle scan of RXMS. This supports the assumption that the depth modulation of the resonant magnetic scattering length corresponds to the depth profile of Au spin polarization. The existence of the uniformly distributed spin polarization component through the Au layer, which was found with the angle scan measurement, is confirmed again from the detailed analysis of energy-dependent RXMS spectra.

Spin polarization of 5p conduction electrons induced in the Ru layers of antiferromagnetically coupled Co/Ru multilayers is investigated by resonant X-ray magnetic scattering at the Ru K absorption edge. Diffraction profiles around (0002) Bragg angles of Co and Ru are measured with linearly polarized synchrotron radiation X-rays of 22.119 keV whose polarization vector is in the scattering plane (p-polarization). The resonant magnetic diffraction profile is extracted by reversing the direction of magnetic field applied perpendicular to the scattering plane. The shape and size of the depth distribution of resonant magnetic scattering amplitude are estimated from the magnetic diffraction profile. It is found that the magnetic scattering amplitude of Ru attenuates within a few atom layers at the interface like Cu-base systems but the average size of the magnetic scattering amplitude is much larger than that of Cu-base systems, suggesting a stronger induced magnetism in the Ru spacer layer.

The applied field dependence of the depth distribution of Au spin polarization is investigated for an epitaxial Fe/Au(001) multilayer with antiferromagnetic interlayer coupling by resonant X-ray magnetic diffraction using circularly polarized synchrotron X-rays near the Au L 3 absorption edge. The magnetic Bragg intensities of the multilayer are measured up to the fifth order with varying the applied field between ±500 Oe. All magnetic diffraction intensities are found to be proportional to the Fe layer magnetization at the same applied field. This result indicates that the size of the induced Au spin polarization parallel to the applied field direction is proportional to the Fe layer magnetization and that the depth distribution of the induced Au spin polarization scaled to the Fe layer magnetization is unchanged during the magnetization process of the antiferromagnetically coupled Fe layers.

Element-specific magnetization processes in antiferromagnetically coupled ferro/ferri/ferromagnetic trilayer systems made of Fe/FeGd/Fe and Co/FeGd/Co were investigated by x-ray magnetic circular dichroism (XMCD) spectra and resonant x-ray magnetic reflectivity (RXMR). The magnetic field dependence of the RXMR intensities at the Gd L 3 -absorption edge for the Fe/FeGd/Fe trilayer and that of the XMCD and RXMR intensities at the Gd L 3 -, Fe K -, and Co K -absorption edges for the Co/FeGd/Co trilayer were measured. The element-specific magnetization processes of Gd moments with the in-plane applied field were compared between the Fe/FeGd/Fe and Co/FeGd/Co trilayers. The experimental results indicate that the Gd magnetization rotates either clockwise or anticlockwise with equal probability in the Co/FeGd/Co trilayer, whereas it rotates in one direction in the Fe/FeGd/Fe trilayer. The magnetic anisotropies along the in-plane directions were estimated for both trilayers from remanence measurements in various ...