Abstract
The variation of the Judd-Ofelt parameters across the isostructural series of ions, [LnW10O35]7- is considered. The parameters are shown to vary in the manner predicted by the Judd-Ofelt theory involving only a static intensity—gaining mechanism. parameters are shown to vary randomly. The results are contrasted with those previously published for Ln3+ doped in Y2O3. The variation of for the lanthanide aquo ions is briefly discussed.