Raman scattering by KI containing F centres

Raman spectra of KI (F centres) are described and calculated in the “off resonance” approximation neglecting the spin of the F centre electron. The theory predicts a very intense Γ resonant mode at 96 cm−1 in agreement with the experiment but is unable to account for the observed depolarization of this mode. Application of Henry's theory shows that this effect can be partially due to the spin—orbit coupling of the F centre in its first excited state. Les spectres Raman de KI (centres F) sont decrits et calcules en dehors des conditions de resonance et en negligeant le spin du centre F. La theorie prevoit bien un mode intense resonant a 96 cm−1 de symetrie Γ mais ne rend pas compte de la depolarisation experimentale de la raie. L'application de la theorie de Henry montre que le terme de couplage spin orbite du centre F au ler etat excite peut interpreter, tout au moins en partie, cette anomalie.