Unravelling local atomic structure in miscible and immiscible binary alloys by EXAFS

We propose to use extended x-ray absorption fine-structure (EXAFS), augmented by molecular dynamics (MD) simulations, to determine nanoscale formation in Ag0.5Cu0.5 and Ag0.5Au0.5 thin alloy films (thickness ~1 µm). Samples will be synthesized by means of a novel sputtering-based method which allows us to tune the temporal profile of multicomponent deposition fluxes, and thereby atomic arrangements, with sub-monolayer resolution. Concurrently, EXAFS is the tool of choice for revealing the element-specific local atomic environment for each pair of atomic species in compositionally complex materials. The selected binary alloys are ideal model systems the study of which will provide us with unique insights into fundamental mechanisms that govern atomic self-assembly at the nanoscale. The latter is a major roadblock faced today by the materials science community towards developing strategies for creating bespoke materials.