A. Markowicz

X-Ray Methods

Two groups of X-ray methods are now widely applied to the study of environmental samples for geochemistry and pollution investigations, X-ray emission spectrometry (XRS) and X-ray diffraction (XRD), and the underlying physical principles of these methods and their limitations are well understood. XRD is indispensable for the investigation of the crystal structure of matter. Since the wavelengths of X-rays are of the same order of magnitude as the distances between atoms in a crystal (approximately 10-10 m), the diffraction effects provide a detailed picture of the contents of the crystal at the atomic level. Using XRD measurements one can determine the crystal structure (interatomic distances, bond angles, planarity of a particular group of atoms and angles between planes) and perform a quantitative chemical analysis (speciation) as well.