Features of crystallization Ag-Au alloy nanocusters

Abstract

In the production of SERS (surface enhanced Raman scattering) substrates, two main approaches to the formation of an array of plasmonic nanoparticles are used: photolithography and chemical methods. Each of them has its own advantages and disadvantages. Vacuum thermal evaporation can also be used. It was chosen for analysis by computer simulation. For this, molecular dynamics simulation of the processes of crystallization of an array of binary Ag-Au nanoparticles was used, which makes it possible to smoothly control the plasmon resonance wavelength. Three arrays of Ag-Au NPs with a diameter of 2,0; 4,0 and 6,0 nm of various target compositions from Ag90Au10 to Ag50Au50 were created. They were subjected to the procedure of cooling from the melt with different rates of the thermal energy removal. In the course of modeling the formation of the internal structure of Ag-Au nanoparticles, conclusions were drawn about the dependence of these processes on the target composition, size, and level of thermal exposure. Based on the regularities obtained, adjustments were made to the technological process of creating SERS substrates using binary Ag-Au nanoparticles.

Keywords

• nanoclusters
• silver
• gold
• crystallization
• structure
• computer simulation
• tight-binding