A previously developed method for analyzing constitutional vacancies, antisite atoms and triple defects was extended to the present system. It was noted that, because the affinity of Cu for Al was smaller than that of Ni, the Cu was able to migrate more extensively, than Ni, from the Ni sub-lattice to antisite positions in the Al sub-lattice. The distribution of the vacancy content across this ternary field was shown to reflect the effects of configurational entropy. The presence of constitutional defects in non-stoichiometric alloys reduced the entropy gain which arose from the formation of Cu-based triple defects. This then decreased the effectiveness of Cu as a promotor of additional vacancies.

A.H.Cottrell: Intermetallics, 1996, 4[1], 1-4