CONDITIONS FOR THE EXISTENCE OF ORDERED STRUCTURE IN BINARY ALLOY SYSTEMS

The conditions for the existence of superlattice structures of fcc binary alloys are discussed by determining the ground state of the pairwise interaction model for arbitrary concentration. The interaction is assumed to extend to the fourth neighboring sites. Many typical ordered structures are obtained as the ground state. The analysis is combined with a calculation of the interaction between two transition element atoms to explain a general tendency observed in transition metal alloys.