On the role of the electronic structure in order–disorder transformation of metallic alloys

Abstract

Diffuse scattering of X-rays, electrons and neutrons from binary alloys provide detailed information about the state of compositional short-range order. Angle-resolved photoemission spectroscopy may be used to probe the corresponding electronic structure. Thus in principle these experiments together can shed light on the electronic causes of ordering. In order to facilitate the interpretation of both kinds of experiment from this point of view we develop a first-principles theory for each. Both theories are based on the self-consistent Korringa-Kohn-Rostoker coherent-potential approximation description of the electronic structure and are fully relativistic. To illustrate the power of such an approach we present explicit calculations for the Cu_0·75Au_0·25 system and comment on some recent experiments on this classic example of ordering alloys.