Synthesis and Mechanism of Composition and Size Dependent Morphology Selection in Nanoparticles of Ag–Cu Alloys Processed by Laser Ablation Under Liquid Medium

We have synthesized Ag–Cu alloy nanoparticles of four different compositions by using the laser ablation technique with the target under aqueous medium. Following this, we report a morphological transition in the nanoparticles from a normal two-phase microstructure to a structure with random segregation and finally a core–shell structure at small sizes as a function of Cu concentration. To illustrate the composition dependence of morphology, we report observations carried out on nanoparticles of two different sizes: ∼5 and ∼20 nm. The results could be rationalized through the thermodynamic modeling of free energy of phase mixing and wettability of the alloying phases.