Molecular Model For The Radiative Dipole Strengths And Lifetimes Of The Fluorescent Levels Of Mn2+ And Fe3+ In Ii-Vi And Iii-V Compounds

A molecular model is used to give an overall semi-phenomenological interpretation of the radiative transition probabilities (RTP) or radiative lifetimes (RL) of Mn2+ and Fe3+ in II-VI and III-V compounds. It is shown that the RTP's are primarily controlled by: (i) the mixing of the wavefunctions of the cation and of the ligands (ii) the molecular spin-orbit interaction which involves the spin-orbit: coupling constants zeta(d) of the d electrons of the cation and zeta(p) of the p electrons of the ligands and (iii) the energies of the intermediate levels which appear in the perturbation model.