Diffraction whole-pattern modelling study of anti-phase domains in Cu3Au

The theory of diffraction line broadening from anti-phase domains in L12 intermetallics is reviewed and incorporated in a whole powder pattern modelling (WPPM) approach. The new analytical procedure was tested on Cu3Au filings before and after a thermal treatment to promote a disorder/order transformation with generation of anti-phase domains. The results confirm a prevalence in the ordered phase of conservative {1 0 0} boundaries, even though fractions of different boundaries are also likely to be present. The information provided by the WPPM is completed by the distribution of diffraction domain sizes and by values of average dislocation density and interaction parameters.