Luminescence of Ba1–xLaxF2 + x: Ce3+ crystals

Resumo

The luminescence of BaF₂ crystals with various concentrations of cerium and lanthanum is studied under excitation with X-rays and UV radiation. In the X-ray luminescence spectra of BaF_2–Сe³⁺ crystals, luminescence quenching is observed at a concentration of cerium above 0.1%. In Ba_1–xLa_xF_{2 + x}: Ce³⁺ crystals, an increase in the concentration of lanthanum at a constant concentration of cerium leads to the same X-ray luminescence quenching as that caused by a similar increase in the concentration of cerium. No corresponding concentration luminescence quenching occurs under photoexcitation. The results show that luminescence quenching under X-ray excitation is primarily caused by energy loss at the stage of the transfer of the energy from the matrix to the dopant rather than by the transfer of the energy from excited cerium ions to quenching centers.