Pairwise interactions and the ground state of ordered binary alloys

Abstract

The ground state energy and superstructures of b.c.c. and f.c.c. Ising model systems with first and second neighbor interactions have been examined. A large variety of superstructures with symmetries as low as monoclinic and stoichiometries as strange as A6B are a natural consequence of the search for lowest energy. For non-stoichiometric alloys, two-phase mixtures of ordered structures of adjacent stoichiometries are often the state of lowest energy. These features seem to correspond more closely to those of real systems than would be expected from the usual first neighbor only Ising model. © 1971.