Surface and Bulk Electronic Structure of Disordered Metallic Alloys

The understanding of electronic structure of disordered alloys has advanced rapidly during the last decade, and the basic elements of a band theory of the bulk electronic structure of random alloys have emerged clearly during this period. In providing an overview of this theory, we focus on the question of how the concept of a Bloch energy band generalizes to the disordered case; illustrative examples of Cu-based solid solutions are presented. On the experimental side, the application of angle-resolved photoemission spectroscopy (ARPES) to the alloy problem is discussed. The use of ARPES in this context is quite recent, although extensive studies of alloys, using a variety of solid state techniques, have been carried out. The existing ARPES work aimed at delineating the surface and bulk electronic structure in metallic alloys is reviewed. We also allude to some of the relevant theoretical and experimental issues that arise in connection with developing this application of the ARPES.