Intermetallic compounds were ball-milled in order to introduce defects and promote order-disorder transitions. The degree of disorder, and the defects that were introduced, were investigated in powder samples by means of X-ray and neutron diffraction at ambient and higher temperatures. A pattern-fitting procedure, that was based upon the Rietveld method, was proposed in order to characterize the defects that were introduced by ball-milling. The point defect concentrations were correlated with lattice parameter changes. Reordering during annealing was also monitored by using the same approach. In the present samples, it was noted that the deformation fault probability could be evaluated for all of the considered structures. The antiphase domains could be successfully analyzed only if the powder was not disordered. The twin fault probability depended upon the asymmetry of the peaks, and could be refined only if the diffraction peaks were not very broad.

L.Lutterotti, S.Gialanella, R.Caudron: Materials Science Forum, 1996, 228-231, 551-6