Anomalous scattering and structural dispersion effect in the analysis of hematite-quartz samples by X-ray diffraction

摘要

X-ray diffraction is undoubtedly one of the most successful analytical methods within minerals and materials sciences. It uses the radiation-matter interaction theory to infer about the tridimensional periodic alignment of the units that make up matter allowing correlating the composition of any sample with a radiation scattering profile. In this work, pure samples of hematite and quartz and their controlled mixes were the experimental materials to interpret and infer on the structure and composition of crystalline matter, following an ab initio principle. The diffractograms of the standard samples were treated with available computer programs. The observed scattering patterns showed that the proposed physical -mathematical models are not able to deal with systems that have very different compositional and physical characteristics. Additionally an alternative approach was proposed to treat the scattering profile according to a new conceptual formulation of the structure factor.