Numerical study of gas dynamic processes in conditions of silver nanocluster deposition experiments

Abstract

In this paper, experiments on the deposition of silver nanoclusters are analysed numerically using improved DSMC method. These experiments were made in the Institute of Thermophysics SB RAS recent years, in the context of the development of bactericidal nanocomposite coatings deposition technology. In this paper we analyze the gas-dynamic effects in experimental conditions: the parameters of the gas stream from the silver vapor source, the flow of silver vapors inside the source and in the outflowing jet under different conditions, the movement of silver nanoclusters of different masses (up to 1024 atoms) in buffer gas, expecting different places of nanocluster formation in a source. The simulations revealed a strong nonisothermal state of the source, which was later confirmed experimentally, the site of nanocluster nulceus formation in a source (subcooled confuser of the nozzle) and, finally, show that the process of nucleation of nanoclusters inside a source is of heterogeneous nature. The width of the silver nanocluster jet (of mass 1024 atoms) reaching target according to sumulations, is in good agreement with that obtained in the experiment coating profile on the target substrate in a form of narrow strip made of stainless steel, that further validates the numerical simulations.