Theory of order in ternary alloys—I

Abstract

The theory of order in ternary alloys as generalization of a theory of binary alloys is given. It is shown that for the description of the long-range order in ternary alloys a set of linear independent long-range parameters is needed. The number of these long-range parameters is fully determined. For the calculation of configurational energy, the method of finding the average number of pairs of atoms of mutual distance r is given. The long-range order is considered on basis of generalization of the Bragg-Williams theory. The general discussion of the thermodynamic equilibrium conditions of ternary alloys and the application of this theory to the Heusler alloy of composition Cu 2MnAl is also quoted.