Molecular Dynamics Study of the Self-Diffusion of Ions in B₂O₃Melt at High Pressure

Molecular dynamics (MD) simulations were carried out in order to investigate the structure and transport properties of boron oxide melt, as a function of pressure. The simulations show a rapid initial increase in the diffusion coefficients of boron and oxygen ions to ∼5−7 GPa, followed by a slower increase from 7 to 14 GPa. The increase in ion diffusivities is correlated with an increase in the proportion of BO 4 to BO 3 units. These results can be used to help rationalize an increase in growth rate of boron suboxide (B 6 O) crystals, observed from B 2 O 3 −B 6 O melts in the 0−4 GPa pressure range.