Diffraction is the tool for determining atomic and molecular structure of crystalline materials. Materials ordered in regular crystal lattices scatter X-ray in specific directions giving rice to a pattern containing information of the specific structure of the material. By measuring the intensity and scattering direction of X-rays, diffraction offers a way to study material on the smallest length scales.
Diffraction can be performed on single crystals, crystalline powders, nanoparticles and thin films. The precise measurement of atomic structure makes it possible to characterize samples on the atomic level as well as to track changes in materials e.g. due to heat, aging, corrosion or other stresses the sample has been exposed to.
Materials with crystalline properties are forming a huge group of the materials we surround ourselves with – everything from metals and ice to paint and some plastics – and their structure are often crucial for their performance.
A single crystal scatters X-rays (or neutrons) in discrete directions. The intensities of these diffracted beams are used to solve the atomic structure.
A powder consisting of a huge number of small crystals will give rise to concentric cones of scattered radiation. Often the data are reduced to a plot of intensity as a function of scattering angle, which can be used for identification and/or structural refinement.