Europium as a luminescent probe of an aluminoborosilicate nuclear glass and its weathering gels

Site distribution of Eu³⁺ ions was studied by site selective spectroscopy in an aluminoborosilicate nuclear glass and in its leached form called gel. Spectroscopic studies allow one to detect two types of site distributions in the glass as well as in two gels. One is attributed to a silicate environment while for the other one an aluminate environment is suspected. Tunable dye-laser excitation spectra show that bandwidths are narrower in gels than in glass so that the site distribution is narrower in gels. Moreover, site symmetry is higher in gels than in the glass.