VIBRONIC SPECTRA OF SrF2:Sm2+AND BaF2:Sm2+

摘要

Recent work of D. L. Wood and W. Kaiser has yielded vibronic data on Sm doped in two isomorphic crystals, SrF and BaF. model using Born-von Karmann boundary conditions, which predicts the number of vibronic satellites and the k = 0 selection rules, is proposed in this report. It is shown however that the k = 0 selection rules are too restrictive to explain the vibronic spectrum and that to obtain a satisfactory explanation transitions involving vibrations away from k = 0 must be considered. The model, when such transitions are taken into account, is shown to be con sistent with the observed data. It is proposed that one of the modes observed in the vibronic spectrum corresponds to vibrations of the transverse optical branch, a second to the longitudinal optical branch, and a third to transitions away from k = 0 involving the Raman active branch.