neutronendiffraction

Neutronendifftration, commonly called neutron diffraction, is a technique used to determine the arrangement of atoms in crystalline materials by observing the pattern formed when a beam of neutrons is scattered by the sample. Neutrons interact with atomic nuclei via the strong nuclear force and can interact with magnetic moments of unpaired electrons, providing information about both crystal structure and magnetic order. The scattering length varies irregularly among elements and isotopes and is not simply related to atomic number, allowing neutron diffraction to distinguish isotopes and to reveal site occupancies that are difficult to obtain with other probes.

A key advantage of neutron diffraction is the deep penetration of neutrons into materials and their sensitivity to light elements such as hydrogen, carbon, and lithium, as well as to magnetic moments. This makes it especially useful for locating light atoms in the presence of heavier ones and for studying magnetic structures and phase transitions. Neutron scattering can thus complement X-ray diffraction, which is more sensitive to electron density and less informative about magnetism.

Experiments are conducted at neutron sources, including research reactors and spallation facilities, using powder diffraction and single-crystal diffraction geometries. Data are analyzed with crystallographic models and refined through methods such as Rietveld refinement for powders or full-matrix refinement for single crystals. Outputs include crystal and magnetic structures, occupancies, and strain information. Limitations include limited access to facilities and comparatively lower flux than some X-ray sources, but the unique capabilities for light elements and magnetism make neutron diffraction a valuable tool in materials science, chemistry, and biology.