[en] We report on the study of a magnetic dislocation in pure chromium. Coherent X-ray diffraction profiles obtained on the incommensurate Spin Density Wave (SDW) reflection are consistent with the presence of a dislocation of the magnetic order, embedded at a few micrometers from the surface of the sample. Beyond the specific case of magnetic dislocations in chromium, this work may open up a new method for the study of magnetic defects embedded in the bulk.

[en] The structure of porous silicon is investigated by grazing incidence x-ray scattering. Using GISAXS (grazing incidence small-angle x-ray scattering), a systematic pore correlation is observed for all porous silicon types. The quantitative analysis of the measurement has been performed for the p^--type sample, using a spherical model of pores and an isotropic distribution of scattering particles, leading to a typical pore size of 6.2 nm and to a particle-particle correlation length of 8.6 nm. In addition for this type of porous silicon, the morphology of the surface and interface of the layer have been studied by specular and off-specular reflectivity. The roughening due to the pore front propagation is quantified and the interface instability of p^--type porous silicon is observed