Gorsky-Bragg-Williams approach to the study of long-period superlattice phases in binary alloys

Abstract

The influence of the shape of the reciprocal-space potential on the relative stability of long-period superlattice (LPS) phases in binary alloys is discussed in a Gorsky-Bragg-Williams approximation. First, for a certain class of LPS phases, the set of pair interaction parameters is reduced to a smaller set of parameters which characterize only the essential aspects of the reciprocal-space potential. Minimization of the free energy for different LPS phases is then used to extract some general tendencies, such as the change of wave vector towards the potential minimum (with increasing temperature) and the increasing stability of complex phases with deepening of the potential minimum.