Abstract
The Judd-Ofelt intensity parameters, (t=2,4,6) for f-f transitions of ions doped in -O (R=Na,K) glasses were determined from optical-absorption measurements, and their compositional dependence was investigated systematically. The values of exhibited a maximum around 25 mol % O, while those of and decreased monotonically with an increase in O content. The compositional dependences of were consistent with those of the isomer shift in Mössbauer spectroscopy, which gives information about the 6s-electron density of ions. The variation of against O content was related to the change in asymmetry of the rare-earth ligand due to the structural mixing of borate groups, while those of were related to the local basicity of rare-earth sites in the glass.
- Received 19 December 1991
DOI:https://doi.org/10.1103/PhysRevB.46.3305
©1992 American Physical Society