On the Optical Properties of Ag-Au Colloidal Alloys Pulsed Laser Ablated in Liquid: Experiments and Theory

We simulated the extinction spectra of Ag-Au alloyed nanoparticles produced by pulsed laser ablation in liquid of elemental targets followed by re-irradiation of suitable mixtures of the obtained colloidal suspensions. When we make use of the optical constants of Ag-Au alloys, our theoretical approach, developed in the framework of the T-matrix formalism, accurately reproduces the experimental features of the extinction spectra of laser-produced nanoalloys with compositions that span the entire composition range (Ag25Au75, Ag50Au50, and Ag75Au25).