Crystal field analysis and electric dipole intensity parameters for holmium in Na 3[Ho(oxydiacetate) 3]· 2NaClO 4·6H 2O

Abstract

Locations and assignments of 104 crystal-field levels have been made for Ho 3+ in the trigonal Na 3[Ho(oxydiacetate) 3]·2NaClO 4·6H 2O system. These energy levels span the 0–36100 cm −1 energy region, and they were located and assigned from axial and orthoaxial (σ and π polarized) absorption measurements on single crystals. The assigned levels are analyzed in terms of a 26-parameter hamiltonian in which six of the parameters are defined to represent the 4f-electron-crystal-field interactions for Ho 3+ ions located at sites with trigonal dihedral ( D 3) symmetry. Quantitative line intensities have been determined for 59 individual 4f → 4f (crystal-field) transitions observed in the low-temperature (10 K) absorption spectra, and these intensity data have been analyzed in terms of a general parametric model for 4f → 4f transition intensities in lanthanide systems. The energy and intensity parametrizations provide a basis for calculating the 4f → 4f absorption spectra of Ho 3+ in Na 3[Ho(oxydiacetate) 3]·2NaClO 4·6H 2O over a wide spectral range, and excellent agreement between calculated and experimentally measured spectra is obtained.