Ge and Ga K-edge EXAFS analyses on the structure of Ge–Ga–S–CsBr glasses

The local structure of Ge and Ga ions in (1 − x)(Ge0.25Ga0.10S0.65)–xCsBr glasses (x = 0.00, 0.05, 0.10 and 0.12) were investigated using extended X-ray absorption fine structure (EXAFS) spectroscopy. CsBr formed [GaS3/2Br]− structural units in glass while Ge ions remained in GeS4/2 tetrahedra, unaffected by CsBr addition. Rare-earth ions can be surrounded by Br ions only when CsBr/Ga ratio in glass became larger than unity.