ABSORPTION AND MAGNETIC CIRCULAR-DICHROISM SPECTRA OF CS2NATMCL6

Absorption and magnetic circular dichroism spectroscopy have been used to study the cubic crystal Cs2NaTmCl6. Transitions between the Oh crystal field levels in 3H6 and3H4,3F3,3F2,1G4 and1D2 have been observed and assigned. Rich vibrational structure was observed in all transitions and the vibrations were assigned within the factor group approximation. The vibrational dispersion over the Brillouin zone is small and all triply degenerate vibrations are split into their longitudinal and transverse components. Transition intensities for magnetic dipole and selected electric dipole (vibronic) transitions were calculated using the ligand polarization model. There was good agreement between the calculated and experimental intensities in a number of transitions. The model failed to predict absolute and relative vibronic intensities within any one crystal field transition. This is probably due to the restricted vibrational model used. © 1979 Taylor & Francis Ltd.