Molecular Dynamic Simulation of Eu 3+ ‐Doped Sodium Borate Glasses and Their Fluorescence Spectra

A molecular dynamic simulation was performed for sodium borate glasses containing a small amount of Eu 2 O 3 to investigate the local structures of cations in glass. A new potential V B‐B in the form ‐A exp[‐C(r ‐ 0.239) 2 ] was added to the regular modified Born‐Mayer‐Huggins‐type potentials, Φ B‐B , Φ B‐O , and ΦO‐O, to account for the directional tendency of the borate network structure. With this potential added, both the radial distribution of sodium borate glasses observed by small‐angle X‐ray diffraction and the change in coordination number of boron with sodium content obtained by NMR agreed well with the simulation. The average coordination number of Ed 3+ ions in the simulated glasses varied from 7.5 to 8.6, depending on the composition of the host sodium borate glasses. The inhomogeneous line width of the 5 D 0 ‐ 7 F z emission peak also changed, depending on the sodium content, with a maximum at 18 mol% Na z O content; this result agrees well with experimental data obtained from laser‐induced fluorescence spectra.