Microdomain model analysis on the negative partial intensity in a disordered ternary alloy

Local atomic arrangements expected in a short-range-ordered ternary alloy system are discussed from the theoretical viewpoint of X-ray diffraction by employing a microdomain model, initially developed for a binary alloy system [Hashimoto (1974). Acta Cryst. A30, 792-798]. It is concluded that a negative partial intensity of short-range-order diffuse scattering is caused by a mixing occupation of two relevant atomic species on the sublattice in the ordered lattice within microdomains, even though there is no heterogeneity of atomic concentration in the alloy crystal, such as a segregation of particular atomic species.