Crystal structures are unique to phases and can indicate the properties connected to a given phase. Of equal importance are the imperfections in the crystals, effecting the properties in materials.
The properties of polycrystalline materials are largely dependent on the nature of their individual crystals. The description of their atomic arrangement is commonly referred to as their crystal structure. Since crystal structures are unique to phases, the determination of crystal structures is a good indicator for a given phase and thus its properties. But besides the perfect arrangement of atoms within a given phase, imperfections in individual crystals, i.e. grain boundaries, point defects, dislocation, area defects and lattice distortions due to strains/stresses, are equally important and have a great influence on the properties of the polycrystalline material.
The crystal structure and defects can be analyzed by diffraction techniques such as X-ray diffraction (XRD), electron backscatter diffraction (EBSD) or various diffraction methods in TEM.