ABSTRACT

This chapter presents a brief description of the physics of X-ray absorption spectroscopy (XAS) and of the data analysis. It describes a selective review of some applications of XAS to the study of sorption phenomena, which include the formation of surface complexes, heterogeneous nucleation, coprecipitation, and solid state diffusion. X-rays with high intensity are required for XAS and are produced by electrons/positrons moving in a storage ring at relativistic energies in paths curved by a magnetic field. XAS consists of recording the absorption by a given sample of X-rays as a function of the wavelength. In X-ray absorption near-edge structure regime, an electron is ejected from a core level of the X-ray absorber toward bond, or delocalized, empty states. Information on the shape, size, and density of particles is usually derived from scattering methods such as light and small angle X-ray scattering.