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We report high resolution x-ray diffraction measurements of (Ga,Mn)As and (Ga,Mn)(As,P) epilayers. We observe a structural anisotropy in the form of stacking faults which are present in the (111) and (111) planes and absent in the (111) and (111) planes. The stacking faults produce no macroscopic strain. They occupy 10 −2 − 10 −1 per cent of the epilayer volume. Full-potential density functional calculations evidence an attraction of MnGa impurities to the stacking faults. We argue that the enhanced Mn density along the common [110] direction of the stacking fault planes produces sufficiently strong [110]/[110] symmetry breaking mechanism to account for the in-plane uniaxial magnetocrystalline anisotropy of these ferromagnetic semiconductors.

The scattering intensity of synchrotron radiation in a compact three‐dimensional volume of the reciprocal space (sinθmax/λ = 0.6283 Å−1) of an SrTiO3 single crystal has been measured at temperatures of 115, 130 and 293 K. The curvilinear features of the diffuse pattern were modelled according to the displacements of both cations correlated along the axis [001]cub (where the subscript cub denotes the cubic structure). The results show that Sr2+ is displaced from the ideal positions along the crystallographic axis [001]cub, forming a short chain composed of about three Sr2+ ions along [001]cub, while the Ti4+ ions are moved in the directions [111]cub, or alternatively [101]cub or [011]cub. The Ti4+ displacements are also correlated along [001]cub, forming a similarly short chain.

X-ray specular reflectivity and diffuse scattering calculated using the traditional multilayer model, which assumes continuous, non-intersecting interfaces, are capable of fitting the experimental data obtained on multilayers with non-continuous interfaces. However, wrong refined electron densities and interface roughness are the consequence of an inappropriate structure model. A modification of the Parratt optical formalism combined with the application of the distorted-wave Born approximation was suggested for evaluation of the small-angle x-ray scattering in multilayers with non-continuous interfaces. The influence of the multilayer discontinuity on the small-angle x-ray scattering is characterized by modified Fresnel reflection and transmission coefficients of individual interfaces and by changes in the optical paths in individual layers. The suggested theoretical approach is illustrated on Fe/Au multilayers. Parameters of the structure model obtained from the small-angle x-ray scattering were verified by comparison with results of transmission electron microscopy.

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The transmission of monochromatic x rays through a CoO single crystal was measured for different orientations of the sample. The small variations in the linear absorption coefficient were considered as a hologram and the real-space image of the local atomic environment was successfully reconstructed. The holographic signal constituted about 1% of the detected intensity. Besides other benefits, the use of the absorption holography can increase the signal-to-background ratio by more than 1 order compared with the fluorescence holography.

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