Relation between Eu²and Ce³f   d-transition energies in inorganic compounds

Data available on the fd-transition energies of Ce 3+ in inorganic compounds are compared with those of Eu 2+ in the same compounds. Despite differing charge compensating defects, clear correlation was found. The redshift of absorption, the Stokes shift of emission, the centroid shift of the 5d configuration and the total crystal field splitting of the 5d levels of Eu 2+ and Ce 3+ all appear to be linearly related to one another. The values for Eu 2+ are about 0.7 times those for Ce 3+ . This implies that spectroscopic properties known for Ce 3+ can be employed to roughly predict spectroscopic properties for Eu 2+ and vice versa. The findings for Ce 3+ and Eu 2+ can be generalized to all trivalent and divalent lanthanides.