Materials Research Bulletin, Vol.35, No.8, 1227-1234, 2000
Fluorescence line narrowing spectroscopy of Eu3+ doped sodium germanate glasses
Sodium germanate glasses of compositions (x - 0.5)Na2O-(100 -x)GeO2-0.5Eu(2)O(3) with x = 10, 16, and 22 were studied using laser-induced fluorescence line narrowing (FLN) techniques. From the site selective luminescence spectra of EU3+ at 20 K, th, energies of the Stark components of the F-7(1) and F-7(2) states were obtained, and a crystal field (CF) analysis was carried out assuming a C-2v site symmetry. The dependence of the CF parameters B-kq on the excitation wavenumber was similar to that observed in other oxide glasses. The behavior of the CF ratios B-22/B-20 and B-44/B-40 appears to be consistent with that calculated using the geometric model proposed by Brecher and Riseberg. The behavior of the CF strength parameter S suggests that the amount of network modifier in the glass host does not influence the CF at the EU3+ sites. NO evidence was found in the FLN spectra of the influence of 6-coordinated germanium.