EXAFS investigation on the structural environment of TM3+ in Ge-Ga-S-CsBr glasses

The local structures around Tm3+ in Ge-0.25 Ga0.10S0.65 and 0.90 (Geo(0.25)Gao(0.10)S(0.65)) - 0.10CsBr glasses were investigated using Extended X-ray absorption fine structure (EXAFS) spectroscopy. In Geo(0.25)Ga(0.10)S(0.65) glass, TM3+ ions are surrounded by approximately seven S ions. Addition of 10 mol% CsBr resulted in significant changes in the EXAFS spectrum of TM3+ ions due to the changes in the local structure surrounding Tm3+ ions. The first-nearest coordination shell around TM3+ ion is predominantly composed of about six Br ions in 0.90 (Ge0.25Ga0.10S0.65) - 0.10 CsBr glass. (c) 2007 Elsevier B.V. All rights reserved.