Influence of excited configurations on the intensities of electric-dipole transitions of rare-earth ions

Abstract

The theory of induced electric-dipole transitions of rare-earth ions in crystals and glasses is improved by taking into account the third-order effects of perturbation theory with respect to the energies of virtual excitations of 4f electrons to the 5d states. Since the energy regions of excited 4f N − 15d states are usually superimposed with the charge-transfer bands, the effects caused by a virtual transfer of an electron from the outer shells of ions of the surroundings (ligands) to the unfilled 4f N shells are also considered. The Pr3+, Sm3+, and Eu3+ ions are considered as examples. It is found that some difficulties inherent in the Judd-Ofelt calculation scheme are successfully overcome. The agreement of the calculated results with the experimental data improves.