The Krivoglaz-Wilkens theory of dislocation-induced X-ray or neutron diffraction line-broadening was adapted for Rietveld refinement of powder diffraction profiles by fitting a Voigt function to each peak. Information on the type of slip system and on the density of dislocations in crystallites could then be found by evaluating the shape parameter and the index-dependent breadth of the Voigt function.

Modelling Dislocation-Induced Anisotropic Line Broadening in Rietveld Refinements using a Voigt Function - I. General Principles. E.Wu, E.M.A.Gray, E.H.Kisi: Journal of Applied Crystallography, 1998, 31[3], 356-62