X-ray and neutron scattering

Scattering experiments are helpful to locate phase transformations. There are classical methods (e.g. powder diffraction) and very sophisticated recent techniques (e.g. quasi-elastic neutron scattering) to study transformations and phase separation in metallic systems. Some examples are discussed. Much space, however, is devoted to studies of inhomogeneities, i.e. deviations from the average structure (point defects, clusters, short-range order, precipitates, etc.). Some remarks on scattering from crystalline materials containing defects are followed by a discussion of X-rays and neutrons as the two types of radiation now commonly used for scattering studies of essentially bulk materials. (Auth.)