Monte Carlo simulations of bulk and nano amorphous silica (a-SiO2) melts

Monte Carlo simulations were carried on bulk and nano amorphous silica (SiO2) melts under different thermodynamic conditions and nano-sizes. The potential developed by Ersan, Tahir, Norman and William (ETNW) was used to model the interatomic interactions of SiO2 melts in both cases (bulk and nano systems). The bulk system was developed using periodic boundary conditions. The nano SiO2 melts were prepared by cutting out a sphere from the bulk amorphous SiO2 melt structure to the required size, and then simulated under free boundary conditions. The high-pressure, high-temperature and nano-size effects on the structure and properties of the melts were investigated and studied via radial distribution functions, radial density profiles, potential energy, density, ring size analysis, coordination number distributions, bond distances and angles. In addition, to understand the difference in properties of bulk and nano silica melts, a comparative study was done at the same thermodynamic conditions. Details of the modelling, simulation results and the study are presented in this paper.