Phase diagram of domain walls in the cubic superstructures of the fcc lattice

Abstract

The thermodynamical behavior of non-conservative [100] domain walls is investigated in the L12 and L10 binary alloys, close to their respective first order–disorder transition lines. Calculations are made using an inhomogeneous cluster variation method in the tetrahedron approximation, within the framework of antiferromagnetic Ising Hamiltonian formulation. Critical phenomena are discussed close to the L12–disorder and L10–disorder transitions, and in the vicinity of the triple point. Different kinds of wetting are exhibited in relation to the relative orientations of the outer variants. The following features are examined: (i) the translational domain wall in the L12 phase is found to be wetted by the disordered phase on the coexistence line; (ii) the orientational domain wall between two L10 variants undergoes a first-order dewetting transition close to the triple point; and (iii) the translational domain wall in the L10 phase undergoes a prewetting transition followed by a wetting process up to the transition line.