Atomic arrangement in immiscible Ag–Cu alloys synthesized far-from-equilibrium

• Published in: Acta materialia Vol. 110; pp. 114 - 121
• Main Authors: Elofsson, V., Almyras, G.A., Lü, B., Boyd, R.D., Sarakinos, K.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.05.2016
• Subjects: Ag-Cu thin films; Arrays; Atomic structure; COPPER SILVER ALLOYS; DIFFUSION; EQUILIBRIUM; FABRICATION; FLUXES; Immiscible alloys; MD simulations; Modulated vapor fluxes; MOLECULAR STRUCTURE; Nonequilibrium synthesis; Strategy; Synthesis; THIN FILMS; Three dimensional; MD simulations; Ag-Cu thin films; Nonequilibrium synthesis; Immiscible alloys; Modulated vapor fluxes
• DOI: 10.1016/j.actamat.2016.03.023
• ISSN: 1359-6454; 1873-2453

Physical attributes of multicomponent materials of a given chemical composition are determined by atomic arrangement at property-relevant length scales. A potential route to access a vast array of atomic configurations for material property tuning is by synthesis of multicomponent thin films using vapor fluxes with their deposition pattern modulated in the sub-monolayer regime. However, the applicability of this route for creating new functional materials is impeded by the fact that a fundamental understanding of the combined effect of sub-monolayer flux modulation, kinetics and thermodynamics on atomic arrangement is not available in the literature. Here we present a research strategy and verify its viability for addressing the aforementioned gap in knowledge. This strategy encompasses thin film synthesis using a route that generates multi-atomic fluxes with sub-monolayer resolution and precision over a wide range of experimental conditions, deterministic growth simulations and nanoscale microstructural probes. Investigations are focused on structure formation within the archetype immiscible Ag-Cu binary system, revealing that atomic arrangement at different length scales is governed by the arrival pattern of the film forming species, in conjunction with diffusion of near-surface Ag atoms to encapsulate 3D Cu islands growing on 2D Ag layers. The knowledge generated and the methodology presented herein provides the scientific foundation for tailoring atomic arrangement and physical properties in a wide range of miscible and immiscible multinary systems. [Display omitted]