Applications of line broadening
Line-broadening analysis is a small but lively field of crystallography. There is an increasing interest in the simultaneous analysis of a number of technologically important properties of polycrystalline materials, e.g. dislocation densities and configurations, planar defects, such as stacking and twin faults, and crystallite size and shape. Simultaneous measurement of these properties is possible because of the increasing ease of modeling the full powder pattern directly. E.J. Mittemeijer (Germany) opened the session with a talk on diffraction-line broadening by lattice imperfections. The next two lectures focused on size-related and strain-related aspects of diffraction line broadening. J.I. Langford (UK) discussed the influence of a crystallite size distribution on size-broadened profiles, focusing on a log-normal distribution. T. Ungar (Hungary) gave an overview of anisotropic broadening by dislocations and emphasized the connection between the Warren-Averbach type of analysis with analysis of dislocation densities. P.W. Stephens (New York) told of a novel approach to model the anisotropic line broadening in Rietveld programs, applicable to the general case of triclinic symmetry. D. Balzar (Colorado) described an application of diffraction line-broadening analysis to a problem of nuclear reactor containment-vessel embrittlement.