Nanoseconds UV laser study of radiationless deactivation from upper electronic excited states in solution: Tb3+

Using 25 ns half width pulses of a frequency-quadrupled Nd laser at 265 nm Tb³⁺ perchlorate in D₂O solution, or in borate glass, was excited to high electronic states and the fluorescence on transition from the upper ⁵D₃ and lower ⁵D₄ excited states to various sub-levels of the lowest ⁷F state were measured. The appropriate energy gap spacing of this rare earth ion results in lifetimes which enabled us to observe the decay of ³D₃ as well as the growing in and decay of ⁵D₄. Radiationless processes from ⁵D₃ direct to ⁷F or cascading to ⁵D₄ are discussed and correlated with previous theoretical and experimental results on related systems involving the interaction of the non-complexed solvated ion with the medium, and compared with related phenomena in glassy solids.