Molecular Dynamics Simulation of the Structure of BaF2-BaO-La2O3-B2O3 Glasses

The structure of the BaF2-BaO-La2O3-B2O3 glasses was investigated using X-ray diffraction (XRD), nuclear magnetic resonance spectroscopy (NMR), and molecular dynamics (MD) simulation. The total correlation functions calculated from the prepared structural models using the MD simulation successfully reproduced the XRD measurements. In the structural models, the fraction of BO4 units increased with the increased fluorine (F) concentration. Furthermore, the introduced F atom is found to bond with Ba and La atoms but barely bonded with boron atoms, as confirmed through boron-11 and fluorine-19 NMR spectroscopy experiments. Furthermore, the structural models showed that an increase in F atoms increased the heterogeneity of the glass structure.