Electronic spectra and crystal-field analysis of DyCl3- 6 in elpasolite lattices

The luminescence spectra of dilute Cs2NaGdCl6 : DyCl3- 6 and the absorption spectra of Cs2NaDyCl6 have been recorded between 5–300 K. The transitions studied in emission include those from 4F9/2 to the 6 H 15/2, 6 H 13/2, 6 H 11/2, 6 H 9/2, 6 F 11/2, 6 H 7/2, 6 F 9/2 and 6 F 7/2 terminal multiplet terms. Irreducible representations are assigned to the crystal-field components of these terms from the comparison of the calculated and observed magnetic-dipole intensities of electronic origins. The luminescent levels of 4 F 9/2 are reassigned and the detailed analyses of the luminescence spectra enable many further changes and additions to be made to the energy level scheme of Dy3+ in octahedral symmetry. Forty out of the possible 44 lowest energy levels have been located from the emission and absorption studies and the agreement with calculation is good.