Luminescence and energy transfer properties of Sm3+ : borate glasses

The photoluminescent properties of borate based glasses that include: B 2 O 3 -PbO; B 2 O 3 -PbO-LiF; B 2 O 3 -ZnO; B 2 O 3 -ZnO-LiF; B 2 O 3 -ZnO-PbO and B 2 O 3 -ZnC-PbC-LiF with various Sm 2 O 3 concentrations (0·01, 0·1,1·0 and 2·5 mol%) have been investigated. The luminescence spectra and lifetimes of 4 G5/2 level of sm. 3+ ions in these glasses have been measured using the 476·5 nm line of argon ion laser as an excitation source. In the binary glass systems studied, Sm 3+ -doped B 2 O 3 -ZnO is having higher lifetimes for the 4 G 5/2 level than B 2 O 3 -PbO system. When the oxyborate glasses are modified with LiF, a considerable increase in the lifetime has been noticed. The decay curves for these glasses are single exponential for lower (≤0·1 mol%) Sm. 3+ ion concentrations, but they become non-exponential with increasing concentration. The non-exponential decay curves have been well fitted to the Inokuti-Hirayama model and it is found that the interactions responsible for the energy transfer is of dipole-dipole type.