V. Lavin et al., On the local structure of Eu3+ ions in oxyfluoride glasses. Comparison with fluoride and oxide glasses, J CHEM PHYS, 115(23), 2001, pp. 10935-10944
Broadband and fluorescence line narrowing optical spectroscopic studies hav
e been used to investigate the local environments of Eu3+ ions in lithium f
luoroborate glasses. From the vibronic spectra, different borate groups cou
pled with the Eu3+ ions have been identified. A pulsed tunable dye laser ha
s been used to selectively excite the D-5(0) level of the Eu3+ ion and the
subsequent D-5(0)--> F-7(1) fluorescence spectra have been monitored as a f
unction of the exciting wavelength. From these FLN studies, three F-7(1) St
ark levels have been identified and a C-2v orthorhombic symmetry has been a
ssumed in the subsequent calculation of the crystal-field parameters for th
e different environments occupied by the Eu3+ ions in the glass. The second
rank crystal-field parameters have been systematically analyzed for the Eu
3+:lithium fluoroborate glass from the site dependent behavior of the F-7(1
) level splitting. The importance of the J-mixing in the crystal-field anal
ysis has been emphasized. An appropriate method for comparing the crystal-f
ield interactions in different glasses has been proposed by analyzing the F
-7(1) level. Thus, results obtained for the Eu3+:fluoroborate have been com
pared with recalculated results in other Eu3+ doped fluoride, borate, silic
ate, and borosilicate glasses. An intermediate behavior between Eu3+:oxide
and Eu3+:fluoride glasses is observed for the local structure of the Eu3+ i
ons in the fluoroborate glass, indicating the active participation of fluor
ine ions in the immediate environments of the lanthanide ion in this glass.
(C) 2001 American Institute of Physics.