Correlation between the 5d-level position of Ce3+ and of the other Ln(3+) ions in solids

The experimental values of the lowest 4f-5d transitions of the lanthanide i ons Ln(3+) have recently been found to show a linear dependence as a functi on of the corresponding transition energy of the Ce3+ ion for a series of d ifferent hosts. We explain this behavior on the basis of an interaction bet ween the induced multipole moments on the ligands and the electrons on the metal, decreasing the energy difference between the 4f(n-1)5d and 4f(n) con figurations with respect to the free ions. (C) 2001 Elsevier Science B.V. A ll rights reserved.