Theoretical Survey of the Sidebands ofSm2+Fluorescence in BaF2

Abstract

We have investigated the one-phonon sidebands of the fluorescence of divalent samarium in barium fluoride. Transitions from ${}_{}{}^5{}_{}{}^{}D_0^{}{}_{}{}^{}$ to the three multiplets ${}_{}{}^7{}_{}{}^{}F_0^{}{}_{}{}^{}$, ${}_{}{}^7{}_{}{}^{}F_1^{}{}_{}{}^{}$, and ${}_{}{}^7{}_{}{}^{}F_2^{}{}_{}{}^{}$ have been calculated in the crystal-field approximation. Fair agreement is found not only for their frequency dependence, but also for their absolute intensities, which are compared to the intensity of the magnetic-dipole ${}_{}{}^5{}_{}{}^{}D_0^{}{}_{}{}^{}\to {}_{}{}^7{}_{}{}^{}F_1^{}{}_{}{}^{}$ zero-phonon transition. A sum rule is developed which uniquely specified all the angular properties of the transitions in terms of one parameter for every contributing multipole. Estimates of the amplitudes of these contributions lie within a factor of 3 of the experimental values. However, significant deviations remain which are attributed to the effects of electron delocalization.