An analytical expression, valid for any crystal system, was proposed for the diffraction contrast factor of dislocations lying along a dyad axis with another dyad perpendicular to it. This symmetry requirement was common to several known  slip systems, so the proposed solution could provide a direct relationship between diffraction line broadening, dislocation slip systems and elastic properties. As an example of the utility of the contrast factor in analytical form, the main slip system, <1¯10>{001}, of fluorite-type structures was considered and the dependence of line-broadening anisotropy given as a function of elastic anisotropy and Poisson's ratio.

Analytical Contrast Factor of Dislocations along Orthogonal Dyad Axes. J.Martinez-Garcia, M.Leoni, P.Scardi: Philosophical Magazine Letters, 2008, 88[6], 443-51