Fluorescence ofSm3+in CaF2

Abstract

The fluorescent "Spectra I and II" of ${\mathrm{Sm}}^{3+}$ in Ca${\mathrm{F}}_2$, consisting of approximately eighty lines, are found to fall naturally into six subgroups each of which has a mean frequency tending to identify it as a set of transitions between the crystal field split levels of one upper fluorescent and one lower ground multiplet free-ion state of known energies. Substantiation of the free-ion origins of these six subgroups is obtained by deducing crystal field energy level schemes, based on the group theoretical symmetry surrounding the Sm ion, which are in accord with the frequencies of the eighty observed lines to within the experimental tolerance of 5 ${\mathrm{cm}}^{-1\mathrm{}}$, maximum. This preliminary analysis indicates that Spectrum II originates from the lowest fluorescent state, ${}_{}{}^4{}_{}{}^{}F_{\frac{5}{2}}^{}{}_{}{}^{}$, and that Spectrum I originates from the second lowest fluorescent state.