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.
Faulting in finite face-centered-cubic crystallites
Beyerlein, Kenneth Roy;Scardi, Paolo
2011-01-01
Abstract
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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione