Energy transfer phenomena and Judd-Ofelt analysis on Sm³⁺ ions in K₂GdF₅ crystal

The Raman, absorption, luminescence spectra and lifetimes curves of Sm³⁺-doped K₂GdF₅were measured. Based on the Judd-Ofelt analysis, the values of radiative transition probabilities, branching ratios, integrated emission cross-sections and radiative lifetimes of excited states of Sm³⁺ in K₂GdF₅ crystal were calculated. The migration of excitation energy between the Gd³⁺ ions and the trapping processes of Gd³⁺ excitation energy by Sm³⁺ and Tb³⁺ions in K₂GdF₅ crystal are reported. The role of the overlapping between the broad, allowed absorption bands of the RE³⁺ ions and the narrow absorption lines ⁶I_J and ⁶P_J of Gd³⁺ ions on the trapping rates of the RE³⁺ was discussed. The energy transfer between the Sm³⁺ ions was studied by the decay measurement, which has been fitted by Inokuti-Hirayama energy transfer model and revealed that electric dipole–quadrupole interaction is responsible for the energy transfer process in Sm³⁺ ions doped K₂GdF₅ crystal.