LAUSR

Abstract K5GdLi2F10 compound doped with Tb3+ and Eu3+ was synthetized. The excited states of these lanthanide ions were analyzed up to VUV range at 125,000 cm−1 (80 nm). Strong coupling between terbium and europium was found. The energy transfer processes from terbium to europium mainly depend on fast migration. The lifetime of 5D4 multiplet in the presence of europium is shorter by about 30% in comparison to singly doped terbium compounds. The character of the decay curve of the 5D4 multiplet is mono-exponential. Non-exponential character was discovered in the case of 5D1 europium multiplet in the presence of terbium. The nature of this quenching was determined to be dipole-dipole interaction with critical distance 9.96 A. The energy transfer is temperature dependent.