Abstract: Molecular dynamics simulation is employed to investigate the relation between the properties of ultra-thin films and their microstructure. Solid-to-liquid ratio is introduced to estimate the solid-like of microstructure. In the process of simulation, the effects of the temperature and the film thickness on the solid-to-liquid ratio and the friction force are investigated. It is concluded that the friction force increases with the solid-to-liquid ratio. But the atomic mass of the solid wall has reverse effects on this phenomenon. It is postulated that the slip length increases with the increase of the atomic mass of the solid wall, which in turn reduces the friction force.

Key words: Microstructure, Molecular dynamics simulation, Slip length, Solid-to-liquid ratio, Ultra-thin film