Optical spectra and crystal field analysis of Sm3+ in the cubic Cs2NaYCl6 host

Optical absorption and emission measurements are reported for the Cs2NaSmCl6 and Cs2NaYCl6:Sm3+ (1 or 30 mol %) systems under variable-temperature (10–298 K) conditions. Twenty-six crystal-field levels spanning 13 multiplets of the Sm3+ 4f 5 electronic configuration are located and assigned on the basis of the experimental data, and these energy level results are rationalized in terms of a nine-parameter 4f-electron Hamiltonian. The most intense electric-dipole vibronic lines observed in the spectra are assigned to one-phonon vibronic transitions associated with the three odd-parity ‘‘moiety’’ modes of the SmCl3−6 octahedral clusters ν3(t1u), ν4(t1u), and ν6(t2u). Intensity calculations are reported for both the no-phonon magnetic-dipole (origin) transitions and the one-phonon (ν3, ν4, and ν6) electric-dipole vibronic transitions.