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We demonstrate a probe of long-range antiferromagnetic (AF) order in FeRh thin films using non-resonant magnetic x-ray scattering. In particular, x-rays at energies below the Fe K-edge have been used for the observation of magnetic Bragg peaks. Due to the low efficiency of the magnetic scattering, a grazing incidence geometry was used to optimise the diffracted intensity from the thin film samples. Based on Scherrer analysis, we estimate a coherence length similar to previous reports from x-ray magnetic linear dichroism (XMLD) experiments, indicating that domain sizes are limited to 40 nm which is consistent with the grain size. The temperature dependent behaviour of the AF order shows an inverse correlation with the emergence of the ferromagnetic (FM) moment, as expected from the phase diagram. [ABSTRACT FROM AUTHOR]

Non-resonant and element specific magnetic X-ray scattering has been used to determine the orientation of Eu and Fe magnetic moments in EuFeAs iron pnictide. Experiments have been carried out on single crystal samples at the ESRF. Resonant measurements on magnetic reflections at the Eu L absorption edge indicate that the orientation of the Eu moments in the antiferromagnetic phase ( T< T=19 K) lie parallel to the crystallographic a-axis. In addition, non-resonant magnetic X-ray measurements indicate that the Fe moments are aligned along the same direction in the spin density-wave ordered phase ( T< T=190 K). The temperature dependence of the integrated intensities suggests that the Fe magnetic sublattice is barely affected by the onset of Eu ordering at T. The observation of non-zero resonant intensity on nuclear-forbidden reflections with wavevector corresponding to the Fe magnetic propagation vector at both the Eu L and As K absorption edges may be interpreted as the result of the polarization of the Eu 5d and As 4p electronic bands via hybridization with the Fe 3d states. [ABSTRACT FROM AUTHOR]

An epitaxial film of NdNiO3 was investigated by the resonant X-ray scattering technique. Below the metal-to-insulator transition a pronounced energy dependence of the scattering intensity at the Ni K-edge is observed. This is clear evidence for a charge disproportionation on the Ni site, leading to two different electronic Ni ions. The occurrence of a reflection in the σ–π channel, its weakness and its azimuthal dependence together with a symmetry analysis gives clear indications that the observed energy dependence in the σ–σ channel is not due to the asphericity of the Ni 4p shell, but is directly related to the charge disproportionation. [Copyright &y& Elsevier]

Abstract: Resonant soft X-ray scattering at the Dy edges has been used to study orbital order in . The charge forbidden Bragg reflection appears below the antiferroquadrupolar ordering temperature, and its temperature dependence is studied through the lower lying magnetic ordering temperature . The energy dependence of the resonant reflection indicates more than one scattering component. In contrast to earlier suggestions, no evidence for the lock-in of the orbitals is observed at . [Copyright &y& Elsevier]

Non-resonant X-ray diffraction measurements have been made on a dense Kondo material CeB6. A series of (n, n, n) reflections with n=half integers has been observed in phase III of this compound. The magnetic field dependence of these reflections at 1.6 K as well as the temperature dependence in zero field have been measured. The intensity of these reflections shows anomaly at the phase boundaries determined by Effantin and coworkers. From these experimental observations, we argue that the (n, n, n) reflections reflect an antiferro-quadrupolar(AFQ) ordering and AFQ moments are coupled to the magnetic dipole and/or octupole moments. [Copyright &y& Elsevier]