Theory of ligand-induced non-radiative relaxation in lanthanide complexes

Abstract

A theory of ligand-induced non-radiative relaxation in rare earth crystals has been developed within the framework of the dynamic coupling model. We have analysed the role played by the following important guiding factors determining the rate of the f^N-f^N radiationless transition: (a) the states with opposite parity, (b) the electronic symmetries of the initial and the final states of the rare ion, (c) the energy gaps between the involved states, (d) the symmetry of the crystal field, (e) the internal promoting and accepting modes of the ligand and (f) the dipole moment and polarisability of the ligand.