EMISSION-SPECTRA AND LOCAL SYMMETRY OF THE EU3+ ION IN POLYMER ELECTROLYTES

The emission spectra of poli(ethylene oxide) (PEO) and Poli(propylene oxide) (PPO) modified by different concentrations of europium bromide, PEOnEuBr3 (n=8,12,16,20,24,28,32,80) and PPO(n)EuBr3(n = 32,80), were recorded and the observed lines assigned to the intra 4f(N=6) 5D0,1 --> F-7(0.4) transitions. The corresponding Stark levels were identified for the F-7(0.4) and 5D0 states. The luminescence of both these polymer complexes (presenting almost identical characteristics) is sufficiently intense to suggest their use as possible luminescence devices. The local coordination of a rare-earth ion in polymer electrolytes is attempted. We used a local-field interaction model, the polarization behavior of the 5D0 --> F-7(0) transition, certain moment operators, and the allowed optical activity of the F-7(F-2, F-3, F-4) components for identifying the approximate local symmetry of Eu3+ to the C2v point group.