A unified model to refine nanocrystalline, layered and faulted material structure and microstructure from powder diffraction data

We have developed and implemented a new algorithm to simulate the powder diffraction pattern of structures containing planar faults. The new model extends the Whole Powder Pattern Modelling idea (Scardi et al., 2002) to take severe faulting into account via a recursive description of the stacking (Treacy, et al.1991). Any source of instrument- and specimen-related line profile broadening, including arbitrary domain shape and size distributions, can be easily considered. By extending the DIFFaX+ idea (Leoni et al., 2004), the new algorithm can be employed to refine both structural and microstructural parameters (including types and probabilities of faulting) from X-ray, electron and neutron diffraction data. Model and examples are shown and commented.