The nucleation of a nanoparticle of silicon dioxide in a closed domain. Computer experiment

The method of molecular dynamics is used to study $\mathrm{SiO}_2$ clusters located in cavities of spherical, cylindrical, and cubic shape. The effect of the elastically stressed state of the cell boundaries on the physical properties of nanoparticles contained in them is investigated. Given the same pattern of application of external forces, a nanoparticle in a spherical cell experiences a stronger compression than in clusters surrounded by envelopes of other geometries. The clusters assume the shape of the cavity in which they were contained. The effect of compressive forces results in the breakage of $\mathrm{Si}$–$\mathrm{O}$ bonds and in the subsequent oxygen enrichment of the cluster surface. The behavior of nanoparticles after the elimination of the stimulation by the cavity boundaries is treated. It is only for a cluster of spherical geometry that a significant number of $\mathrm{Si}$–$\mathrm{O}$ bonds is restored. For other clusters, the evaporation of oxygen atoms is observed.