Temperature effects on radiative and radiationless transitions of Gd3+ in solution

Temperature effects on the fluorescence of Gd3+ in H2O solution are presented and discussed. The quantum yield does not approach unity near the freezing point. In the case of Gd3+, high energy vibrations of single solvent molecules do not quench the fluorescence. The results are interpreted by use of the ``junction'' mechanism involving the ion and solvation shell [Y. Haas and G. Stein, J. Phys. Chem. 76, 1093 (1972)] and by clarifying the role of the levels giving rise to a broad band in both absorption and emission in solution.