Pairwise interaction energies in iron-aluminium alloys

Abstract

The APB energies in ordered Fe-Al alloys which were measured by the weak-beam technique in the previous paper, have been interpreted in terms of ' reduced ' pairwise interaction energies (V_j ) between neighbouring atoms. It has been found that the first nearest-neighbour interaction energy (V ₁) increases slowly with concentration of Al while the second nearest-neighbour interaction energy (V ₂) decreases rapidly. The present values have been compared with those derived by other, less direct methods, particularly from thermodynamic theories. They are of the same order of magnitude but significant differences occur. These differences are thought to be due mainly to assumptions and approximations made in the theoretical treatments on which these other methods are based.