Judd-Ofelt parameters obtained from the absorption spectra of Eu3+ ions doped in PbO-PbF2 glasses are intermediate between the values for fluoride and phosphate glass matrices. Eu3+ ions are coordinated to both oxide and fluoride ions. The calculated transition probabilities (As-1) for the laser transition5Do→7F2 are 171 and 170 for 30PbO-70PbF2 and 70PbO-30PbF2 glasses respectively and are significantly lower compared to phosphate glasses. The calculated (βR cal) and experimental (βRexpt) branching ratios for this transition show good agreement. The emission spectra display high energy transitions in the 440–570 nm region, a characteristic of parent matrices with low energy phonons such as the tellurite, germanate and fluoride glasses. The electron-phonon coupling strengths deduced from the excitation spectra of Eu3+ are 10.2 x 10−3 and 9.5 x l0−3 for 30PbO-70PbF2 and 70PbO-30PbF2 glasses respectively. The relative emission intensities of the low energy transitions to high energy transitions and the ratios of the most intense transitions5D0→7F2/5D0→7F7 significantly vary for the two glasses providing evidence for clustering of Eu3+ ions with increase in its concentration and increasing PbO content.
Volume 134, 2022
Continuous Article Publishing mode
Click here for Editorial Note on CAP Mode