INTERATOMIC FORCES AND ATOMIC-STRUCTURE OF LIQUID AL80MN20 ALLOYS

A tight-binding-bond approach to interatomic forces in disordered alum inium-transition-metal (Al-M) alloys is presented. The bond order is c alculated on a Bethe lattice reference system, well adapted to topolog ically disordered alloys. It is shown that the bond order depends stro ngly on the strength of the pd hybridization in the Al-M alloy, leadin g to non-additive potentials with a strong preference for the formatio n of pairs of unlike atoms and short bond distances in the Al-M pairs. This is illustrated by studying the structural properties of liquid A l80Mn20 alloy using molecular-dynamics simulations and by comparing ou r results with the available experimental ones.