Molecular dynamics study on coalescence of silver (Ag) nanoparticles and their deposition on gold (Au) substrates

Molecular dynamics (MD) simulation was conducted to investigate the coalescence of Ag nanoparticles and their deposition on a gold substrate at various temperatures from 400 K to 1000 K, using embedded atom method (EAM). Density distribution function, x-z plane projection, spreading index, and coalescence index were analyzed to gain more insights into the sintering and diffusion process. Simulation results showed that Ag and Au atoms can diffuse into each other significantly at a temperature of 1000 K and reform intermetallic lattice structure after the temperature is cooled back to 400 K. Simulation data also demonstrated that even at a low temperature of 400 K, metal spheres can be collapsed and deposited on the substrate. Yet higher temperatures were helpful in enhancing the degree of collapsing and deposition.