Characterization of the preferred orientation in EXAFS-samples

Preferred orientation in powder samples influences extendet X-ray absorption fine structure (EXAFS) measurements due to the polarization of synchrotron radiation. The polarization effect at the uranium LIII edge EXAFS and the analysis of preferred orientation is demonstrated using the natural mineral metatorbernite. For simple textures an X-ray diffraction measurement in Bragg-Brentano geometry allows to determine the crystallite orientation basing on a full pattern refinement including a preferred orientation model according to March-Dollase.