Electronic structure of metallic compounds and alloys: Experimental aspects

The chapter presents a review on the experimental methods for obtaining quantitative information directly relatable to the electronic structure of metallic compounds and disordered alloys, and presents a comparison on the results with theoretical results when the latter are available. There are many measurable quantities which depend on the electronic state; the chapter discusses those experiments that give information that can confront, in a direct way, an energy-band or density-of-states calculation with a significant quantitative test. Electron states in the one-electron approximation are discussed, for it is well known that these states are sufficient to explain many of the observed electronic and optical properties of solids, and because these states are the “zero-order” states upon which any many-body states and phenomena must depend. The chapter explains the ideas behind the experiments, the results which have been obtained, and the comparison of experiment with theory. The chapter presents a brief review only the early, simple models for the electronic structure of alloys and give references to several of the recent theoretical papers, with emphasis on those that are sufficiently close to “reality” ‘(a real alloy system) that quantitative comparison with experiment can be made. The chapter also discusses continually ordered or disordered alloys of a given composition.