Luminescence spectroscopy of theGd-rich Ce<SUP>3+</SUP>-, Tb<SUP>3+</SUP>- and Mn<SUP>2+</SUP>-doped phosphate glasses

Absorption, emission and excitation spectra and luminescence decay kinetics of Na(K)GdCe, NaGdTb and NaGdMn phosphate glasses and their dependence on the temperature (in the 1.7–300 K range) and on the glass composition have been studied. The processes of energy migration through the Gd³⁺ ions and following energy transfer in Gd³⁺-impurity pairs have been compared for the three types of the glasses studied. It has been suggested that the Gd³⁺ → Tb³⁺ energy transfer occurs only in the closest pairs through a very short-range exchange interaction, while the Gd³⁺ → Ce³⁺ and Gd³⁺ → Mn²⁺ energy transfer is possible also in more separated pairs mainly due to the longer-range multipolar Gd³⁺-impurity interaction.