Problems in Diffraction Analysis of Real Polycrystals

摘要: It is well known that X-ray or neutron diffraction phenomena of real polycrystalline materials are often strongly influenced by the microscopical structure (phase content, grain size and orientation, spatial arrangement different phases) scattering object volume. Methodological problems arising from this fact in analysis polycrystals have been treated with regard to systematic errors intensity measurements and, course, connection special applications for microstructure characterization. In most considerations it was implicitly assumed all crystallites a given phase similar (i.e. perfect crystal lattice disorder). Such presumption necessary (and possible) investigations constitution — related characteristics (e.g. electron density, thermal vibrations, short-range order solid solutions) which principle require knowledge single-crystallite therefore must usually be performed carefully prepared (structurally homogenized), fine-grained powder specimens. However, examination process-related parameters dislocation densities due various modes plastic deformation, substructure associated heat treatment, precipitation processes transformations), more becomes dominating problem research, no homogenization treatment structures can carried out general.