An interpretation of the spectra of bivalent rare-earth ions in crystals

Abstract

The 4P,-15dconfiguration behaves according to a J,y, coupling scheme in crystals, where J1 is the total angular momentum of a Russell-Saunders term derived from 4 Pand J,y, is a state of the 5d electron in the crystal field. The spectra of several ions in alkaline earth fluorides and of Sm2+ in alkali halides correspond to 4f"+ Jlym transitions with A, the separation between y3 and y5 in 0,. and Efd, a coulombic parameter, both pointing to a similarity of effects on passing through each half of the series of rare earths.

Lower oxidation states of f elements: II. Physicochemical characteristics of actinides and lanthanides in lower oxidation states

“…The difference between the hydration energies of the Ln 2+ ions in different electronic configurations may characterize the minimal energy of stabilization of the d level (about 1.6 eV for La 2+ and Ce 2+ and about 1.8 eV for Gd 2+ and Tb 2+ ). The values obtained are consistent in the order of magnitude with the splitting energy of the La and Gd d level in the CaF 2 matrix, determined in [68] and equal to 3 eV.…”

“…The absorption spectra of virtually all Ln 2+ in the CaF 2 , SrF 2 , and BaF 2 matrices were measured in [68,74]. These spectra were interpreted using the J 1 g coupling scheme [68] with presentation of all the main diagrams of splitting of energy levels of bivalent Ln ions.…”

“…These spectra were interpreted using the J 1 g coupling scheme [68] with presentation of all the main diagrams of splitting of energy levels of bivalent Ln ions. Using these schemes, Johnson and Sandoe [68] determined the crystal field splitting parameter D, energy of the first unsplit level 4f n 31 5d 1 (E fd ), and distance between the first two unsplit levels of this configuration (E ff ).…”

Europium(II) Complexes With Benzo-18-Crown-6

“…10Ϫ15 min. C 16 3. Compound 2 was the result of an unsuccessful attempt to prepare an acetate salt of the crown complex.…”

“…The difference in wavenumbers between these and the lowest lying excited (emitting) level are 2250, 5150, 9100 and 17060 cm Ϫ1 , respectively. Using the simple approach of Johnson and Sandoe [16] we can interpret the first three maxima as being dominated mostly by 4f 6 ( 7 F)5d states, whereas the last one, lying 17060 cm Ϫ1 above the emitting level, should include mainly the 4f 6 ( 5 D)5d states, as the respective difference parallels that between the energies of the 7 F J and 5 D J levels in Eu 3ϩ .…”