Site-selective spectroscopy of Eu3+ ions in fluoride glasses
1994; Elsevier BV; Volume: 59; Issue: 1-2 Linguagem: Inglês
10.1016/0022-2313(94)90025-6
ISSN1872-7883
AutoresR. Balda, J.F. Fernández, Hergen Eilers, W. M. Yen,
Tópico(s)Lanthanide and Transition Metal Complexes
ResumoThe optical properties of two Eu3+-doped fluoride glasses with the composition (in mol%), 30BaF2-18InF3- 12GaF3-20ZnF2-9.5YF3-6ThF4-4ZrF4-0.5EuF3 and 57ZrF4-18BaF2-5.5LaF3-3AlF3-15NaF-0.5EuF3 were investigated by time-resolved site-selective spectroscopy in order to correlate the glass matrix composition with the Eu3+ spectral properties. The results established the presence of two main site distributions for the Eu3+ ions. The spectral evolution of the time-resolved line-narrowed excitation spectra shows the existence of discrete energy transfer between both sites. The fluorescence-narrowed spectra of the 5D0→7F1 emission at 10 K obtained under resonant excitation show inhomogeneous broadening due to the superposition of fluorescence from the two sites. The estimated average crystal field strength for both glasses grows monotonically with the 7F0→5D0 energy in agreement with other glasses studied. The results allow us to conclude that the degree of local order is high in both glasses producing a high site symmetry for the Eu3+ ions. As a consequence, the lifetimes are longer than those observed in other glasses.
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