Molecular Spin-Orbit Interaction for d5 Ions in Crystals. Spin-Lattice Coupling Coefficients and First-Order Spin-Orbit Interaction for the Fluorescent Levels of d5 Ions

Abstract

The first-order spin–orbit (SO) interaction for the fluorescent 4T1-levels of Mn2+ in the common cation series ZnX (X: S, Se, Te) has been calculated by using the molecular SO interaction HSO mol and a very elaborated ligand-field (LF) model. With respect to the splittings predicted by the crystal-field (CF) model, the first-order SO splittings are very strongly reduced for Mn in ZnS, while for Mn in ZnSe and ZnTe, the splittings are inversed and strongly enhanced. A theoretical check of the validity of the LF model is performed by relating the matrix elements of the total angular momentum for the monoelectronic wave functions 2e and 2t2 which intervene in the calculation of the matrix elements of the first-order SO interaction to those which intervene in the calculation of the spin–lattice coupling coefficients (SLCC). Another check of the validity of the LF model from a previous analysis of the four vibronic lines of the fluorescent level of Mn2+ in ZnS is briefly recalled.