X-ray absorption fine structure determination of the local environment of Er3+ in glass

Erbium LIII-edge x-ray absorption fine structure (XAFS) and I13/24 excited state lifetime measurements were performed on aluminosilicate, fluorosilicate, and phosphate glasses with varying erbium concentration. The local erbium environment is shown to be unique in each host. In the aluminosilicate, erbium is found to have 6.4 nearest oxygen neighbors at a distance of 2.22 Å and with a Debye–Waller factor of 0.031 Å2. Erbium in the fluorosilicate glass was found to be more highly coordinated with 7.5 nearest neighbor anions. Erbium in the phosphate glass is found to have a smaller disorder factor of 0.021 Å2 when compared with the silicate glasses. No variation of the environment (3 shells) is observed with changes in rare earth concentration, while the excited state lifetime varies from 1.0 to 9.8 ms in the aluminosilicates, suggesting the absence of erbium clustering at XAFS detectable distances.