Energy transfer studies in Eu3+-doped lead-niobium-germanate glasses

The spectral migration of energy among Eu3+ ions in lead-niobium-germanate glass (60GeO2-25PbO-15Nb2O5) with different Eu3+ concentrations (0.5, 1, 3, and 5 mol%) has been investigated at low temperature by using time-resolved fluorescence line narrowing (TRFLN) spectroscopy. The spectral features of the time-resolved fluorescence line-narrowed 5D0 → 7F0 emission spectra under resonant excitation at different wavelengths along the 7F0 → 5D0 transition as a function of time, excitation wavelength, and concentration reveal the existence of energy migration between discrete regions of the inhomogeneous broadened spectral profile. The analysis of the time evolution of the 5D0 → 7F0 emission shows that the electronic mechanism responsible for the ion-ion interaction can be identified as a dipole-dipole energy transfer process.