Phase Diagram of a Binary Alloy in the Static Concentration Wave Approximation

The three-sublattice ordering observed in alloys used for special purpose hard magnets is considered. Possible phase diagrams describing the ordering of alloys in systems of intermetallides with RCo2 structure are presented. It is shown that, according to the static concentration wave (SCW) approximation, the main area of the phase diagram is occupied by incongruently melting partially ordered alloys.