Estudio de tamaños medios absolutos de grano por difracción de Rayos X

Résumé

X-ray powder diffractometry has widely proved its interest in acquiring textural information such as crystallite mean size. The consequence of the size effect is a broadening of the lines approximately in inverse ratio to the thickness of crystallites, perpendicularly to the reflecting planes. The relative ratios between the width of the lines on the one hand, and the profile of each line, on the other, are a function of the morphology. But, as these previous crystallinity studies use the so-called indirect methods, they have strong limitations. Here we incorporate direct methods of sample mineral analysis (Image Analysis Process). It shows the morphology and size of the “mean grain” sample, which allows us to fit parameters to a function related to the form factor. This function, applied on the pure diffraction profiles, easily gives us the absolute mean size.