Energy transfer processes in K5Li2GdF10K5Li2GdF10:Eu,PrEu,Pr

In K5Li2Gd0.80Pr0.10Eu0.10F10K5Li2Gd0.80Pr0.10Eu0.10F10 the D1,05 luminescence of europium is quenched by the presence of Pr3+Pr3+. Analysis of the decay curves of the D05 and D15 luminescence, recorded at room temperature, suggests that the Eu3+Eu3+D50 emission is quenched by quadrupole–quadrupole interaction with D21 multiplet of praseodymium. The generalized Yokota–Tanimoto model has been used to explain the behavior of the decay curves and to determine the kinetic microparameters CDACDA, related to the cross relaxation, and D  , related to the energy migration probabilities. The “critical radius” (R0)(R0) for these interaction was calculated to be in the range 10.007–11.528 Å.