Nanoseconds UV laser study of radiationless deactivation from upper electronic excited states in solution: Tb 3+

Abstract

Using 25 ns half width pulses of a frequency-quadrupled Nd laser at 265 nm Tb 3+ perchlorate in D 2O solution, or in borate glass, was excited to high electronic states and the fluorescence on transition from the upper 5D 3 and lower 5D 4 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 3D 3 as well as the growing in and decay of 5D 4. Radiationless processes from 5D 3 direct to 7F or cascading to 5D 4 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.