Parameterization of electric-dipole intensities in the vibronic spectra of rare-earth complexes

Abstract

A parameterization scheme for the electric dipole intensities of one-phonon vibronic (f-f) transitions in rare-earth (lanthanide and actinide) complexes is proposed. This parameterization is perfectly general within the one-electron, one-phonon, one-photon approximation for ion-ligand-radiation field interactions, and it is directly related to a general intensity parameterization scheme proposed previously for purely electronic (zero-phonon) f-f transitions. The parameters in this scheme can provide a basis for characterizing one-phonon vibronic line intensities in f-f optical spectra without recourse to specific model (or mechanism)-dependent considera tions. Applications of this parameterization to the vibronic spectra of octahedral (O h) REL6 systems are discussed, and it is shown how the intensity parameters for these systems may be expressed in terms of a set of ‘intrinsic’ intensity parameters (in the superposition approximation for RE-L interactions). Finally, the parameterization scheme is applied...