Computer simulation of structuring Ag-Cu nanoparticles

Abstract

In this work, computer simulation of the processes of formation of the internal structure of plasmonic Ag-Cu nanoparticles was carried out. Method of molecular dynamics based on the tight binding potential was used. The crystallization of Ag-Cu nanoparticles with a diameter of 2,0-8,0 nm with an atomic copper content ranging from 10 to 50% was simulated. To remove thermal energy, an Andersen thermostat was used with three different cooling rates ΔT/Δt = 30∙1011, 12∙1011, 5∙1011 K/s. The possible structural transitions arising in this case were determined using the radial distribution function and the change in potential energy. To determine the most stable cluster structure, an ensemble of nanoparticles of the same size was taken. Then, using the visualizers OVITO and xmakemol, the real appearance and structure of the studied nanoparticles were found. In the course of the simulation, it was found that at low levels of copper doping in Ag-Cu nanoparticles, the formation of five-particle symmetry is possible. The conditions for the occurrence of this effect were fixed. It was also determined that D = 8,0 nm for Ag-Cu nanoparticles is the size limit, starting from which the macroscopic effect of stabilizing the fcc structure of the eutectic alloy appears under the condition of very fast sample quenching.

Keywords

• nanoclusters
• silver
• copper
• crystallization
• structure
• computer simulation
• tight binding