EXAFS investigation on the structural environment of Tm3+ in Ge–Ga–S–CsBr glasses

Abstract The local structures around Tm 3+ in Ge 0.25 Ga 0.10 S 0.65 and 0.90 (Ge 0.25 Ga 0.10 S 0.65 ) − 0.10CsBr glasses were investigated using Extended X-ray absorption fine structure (EXAFS) spectroscopy. In Ge 0.25 Ga 0.10 S 0.65 glass, Tm 3+ ions are surrounded by approximately seven S ions. Addition of 10 mol% CsBr resulted in significant changes in the EXAFS spectrum of Tm 3+ ions due to the changes in the local structure surrounding Tm 3+ ions. The first-nearest coordination shell around Tm 3+ ion is predominantly composed of about six Br ions in 0.90 (Ge 0.25 Ga 0.10 S 0.65 ) − 0.10CsBr glass.