Molecular dynamics study of boron trioxide glass

Abstract

Boron trioxide (B₂O₃) glass has been simulated here by molecular dynamics using an interionic force law. The parameters for the force law were varied until the results of the simulated system agreed with the experimental findings. The simulation was performed for two systems, one with 64 molecules (128 B and 190 O atoms) and the other with 640 molecules, by slowly cooling the systems from a very high-temperature liquid state at constant volume. The characteristic curves of energy versus temperature and pressure versus temperature show change in slopes around 600K indicating a glass transition in the system. The mean square displacement with temperature also shows a sudden change around this temperature. These properties and the glass transition temperature of small and large systems are very close to each other. The structural analysis of the simulated glass reveals that almost all the boron and oxygen atoms form planar BO₃ triangles.