R. Balda et al., TEMPERATURE-DEPENDENT CONCENTRATION QUENCHING AND SITE-DEPENDENT EFFECTS OF ND3+ FLUORESCENCE IN FLUOROPHOSPHATE GLASSES, Physical review. B, Condensed matter, 53(9), 1996, pp. 5181-5189
The optical properties and temperature-dependent concentration quenchi
ng of Nd3+ fluorescence have been investigated in fluorophosphate glas
ses with different fluorine to oxygen ratios by using steady-state and
time-resolved laser spectroscopy. Judd-Ofelt parameters were derived
from the absorption spectra and used to calculate the F-4(3/2) --> I-4
(11/2) stimulated emission cross section and the F-4(3/2) radiative li
fetime. For the samples doped with 1 wt % of Nd2O3 the lifetimes were
found to be linear dependent on the fluorine to oxygen ratio. From the
thermal behavior of lifetimes, a linear temperature dependence for th
e nonradiative Nd-Nd relaxation processes has been found in the 4.2-10
0 K temperature range for samples with a molar fluorine to oxygen rati
o of 6.04 doped with more than 1 wt % of Nd2O3, which is in agreement
with a one-phonon-assisted process. In order to investigate the influe
nce of the local coordination ions on the optical properties of rare e
arths in these fluorophosphate glasses, fluorescence line-narrowing sp
ectroscopy on Eu3+ has been performed. The influence of the local coor
dination ions on the optical properties of Eu3+ in these fluorophospha
te glasses shows the existence of a clear crossover between the behavi
or of fluorinelike and oxygenlike coordination anions.