Electronic Raman Spectra IV: Relation between the Scattering Tensor and the Symmetry of the Crystal Field*

The scattering tensor for the 7F1–7F0 and 7F2–7F0 electronic Raman transitions of the trivalent europium ion has been calculated for cases in which the rare-earth ion experiences a crystal field of cubic, hexagonal, and tetragonal symmetry. It is shown that such crystal fields give rise to Raman spectra of which polarization features are direct indications of the symmetry of the environment. The 7F1←7F0 transitions are all related to the antisymmetry of a scattering tensor, whereas the 7F2←7F0 transitions are related to a symmetric tensor. According to theory, the latter transitions should be more intense than the former.