AU-NI SOLID-SOLUTIONS STUDIED BY NUMERICAL RELAXATION

A semi-empirical potential based on the tight-binding second moment approximation is used to study Au-Ni solid solutions at 0 K. The energy of formation, the topological disorder, and the elastic constants are analysed within the whole concentration range. The results coincide very well with available experiments and may be explained by a frustration of the interatomic bondings by the fcc lattice. The size effect predominates over the chemical one and the analysis of interstitial sites shows that the local chemical surroundings lead to a splitting of the fcc lattice tetrahedral volumes.