Beyerlein Kenneth R, Snyder Robert L, Scardi Paolo
Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
Acta Crystallogr A. 2011 May;67(Pt 3):252-63. doi: 10.1107/S0108767311009482. Epub 2011 Apr 12.
The effects that planar faults have on the powder diffraction peak profiles of a face-centered cubic (f.c.c.) material are studied considering the case of small crystallites. In doing so a new method to calculate the planar probability correlation function of a faulted crystallite is presented which considers the finite extent of the planar sequence. The resulting correlation function is demonstrated to be dependent on the position of a fault in a crystallite through its proximity to a crystallite boundary. The average correlation function found considering equal probability of a fault existing on each plane in a crystallite is compared with that found by solving a system of recursion relations. The broadened subcomponents of the f.c.c. powder profiles are shown to be related to the correlation function through a general Fourier series expression. This expression is then used to simulate peak profiles from the developed model, and then compare them with those predicted by the recursion relation treatment.
