关键词: 氟化物玻璃, 玻璃结构, 分子动力学, X射线衍射

Abstract: Glass forming regions in the CdF₂-BaF₂-LiF system were determined through melting-quen-ching technique. The structure of 36CdF₂-34BaF₂-30LiF
(mol%) (CBL glass) was studied by X-ray diffraction and molecular dynamics simulation methods. The Cd atoms are six-, seven- and eightfold coordinated by fluorines.
The average Cd--F bond length is 2.29A. The Cd--Cd atom distance is about 3.52A for edge-sharing and 4.03A for corner-sharing in the MD-derived glass. The
glass structure can be discribed as a network made up of edge-sharing and corner-sharing [CdF_n] polyhedra which are partial linked by
Li⁺ ions. The role of Li⁺ ions in the fluoride glasses was discussed. It was proposed that Li⁺ may play the outpolarization effort in fluoride glass as
it does in the oxide one. This effort can play a positive role to the connectivity of the network based on the good glass formers. However, in the
glass based on the weak-bonded glass formers, the relative strong Li--F bond results in a decrease of its chemical durability as it does in the CdF₂-BaF₂-LiF system.

Key words: halide glass, glass structure, molecular dynamics simulation, X-ray diffraction