Cooperative vibronic transitions inEu3+-doped oxide glasses

Abstract

O. The relative intensities of these spectra are analyzed quantitatively on the basis of the cooperative optical transition model proposed by Stavola and Dexter, which assumes that the f -f vibronic transition is allowed by the electrostatic interaction between the rare-earth ion and an oscillating ligand molecule. The fact that the vibronic spectra of the 7 F 0 -5 D 2 and 7 F 1 -5 D 1 transitions are fairly intense compared with the others is shown to be explained well by this model, because these spectra are predicted to occur through the electric dipole-dipole interaction which is the most dominant among the multipole expansion terms of the above electrostatic interaction. The principal mechanisms of the 7 F 0 -5 D 0 and 7 F 0 -5 D 1 vibronic transitions are identified as due to the borrowing of intensities from the 7 F 2 -5 D 0 and 7 F 2 -5 D 1 vibronic transitions respectively, which are predicted to be caused by the dipole-dipole coupling in the above model, via the mixing of the 7 F 2 manifold into 7 F 0 through the second-order component of the crystal-field potential. In addition, the vibronic spectrum of the 7 F 0 -5 D 4 transition is ascribed to the mechanism through the electric octopole-dipole coupling and possibly also to the crystal-field mixing effect for the 5 D 4 manifold. These results show that the interaction of the Eu 3ϩ ion with the vibrations of the surrounding forming units of oxide glasses is described well by the electric multipole-multipole interaction.

Distribution of Eu3+ ions in LaPO4 nanocrystals

“…Finally, the spectra were corrected by the spectral distribution of the excitation light. A rhodamine B-ethylene glycol solution ð3 g=lÞ; whose quantum efficiency is known to be constant in the range of 240-590 nm [12], was used to carry out this correction.…”

Borrowing Intensity in Rare Earth Doped Materials; Magnetic Dipole Transitions

“…1 together with the basic definitions of the approach. An extensive and very precise discussion of these numerical results performed in the context of observations, and also on the background of the impact which is due to other physical mechanisms, is presented in a very elegant and complete way by Kushida and Tanaka. Their contribution to the understanding of these transitions is outstanding [2][3][4][5][6][7][8][9] , however, at the same time, other publications like refs 10,11 , and references in all the papers cited here, should not be overlooked in the discussion.…”

“…Thus, the present analysis is a continuation of a still vivid discussion devoted to the unusual transitions, and might be treated as a new addition to the knowledge presented previously in ref. 1 and in the series of papers by Kushida and his collaborators [2][3][4][5][6][7][8][9] .…”

Local Er(iii) environment in luminescent titanosilicates prepared from microporous precursorsElectronic supplementary information (ESI) available: Er LIII-edge k3-weighted EXAFS spectra and Fourier transforms. See http://www.rsc.org/suppdata/jm/b1/b107136j/

“…The presence of this sideband (DJ ~4) violates the selection rule that arises from the theoretical approaches to vibronic line intensity of lanthanide ions. [40][41][42][43] Similar violations, generally associated with inactive infrared vibrational modes, have been observed for Pr 31 ( 3 H 4 A 3 P 0 ), 40,44 Eu 31 ( 7 F 0 A 5 D 4 ), 43 and Tm 31 ( 1 D 2 A 3 H 6 ). 41,42 The phonon energy corresponding to the observed sidebands is estimated by the energy difference relative to the corresponding electronic transitions.…”