Phonon sidebands and vibrational properties of Eu 3+ doped lead germanate glasses

Abstract

The phonon sideband spectra of the 7F 0→ 5D 0 and 7F 0→ 5D 2 electronic transitions of Eu 3+ are reported and assigned on the basis of the vibrational Raman spectra for a series of lead garmanate glasses of molar compositions ( x − 1)PbO · (100 − x)GeO 2 · 1Eu 2O 3 with x = 30, 40 and 50 mol%. The samples were prepared by melting the appropriate amount of the oxides at 1100°C for 2 h, and quenching and annealing at temperatures from 320 to 380°C for 15 h. The electron-phonon coupling strength of the GeO stretching modes coupled to the 7F 0→ 5D 2 transition was evaluated by determining the ratio of the intensity of the phonon sideband to the intensity of the zero phonon line. With increasing lead content, the coupling strength appears to increase (within the experimental uncertainties) from 0.010 ( x = 30 mol%) to 0.012 ( x = 50 mol%).