Journal of Inorganic Materials

• Research Paper • Previous Articles     Next Articles

X-ray Diffraction and Molecular Dynamics Study of CdF2-BdF2-LiF Glass

JIANG Yang; ZHAO Xiu-Jian; LIANG Kai-Ming+   

  1. Research Institute of Advanced Materials; Wuhan University of Technology Wuhan 430070 China; +Department of Material Science and Engineering; Tsinghua University Beijing 100084 China
  • Received:1997-04-07 Revised:1997-06-06 Published:1998-04-20 Online:1998-04-20

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 [CdFn] 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

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