Jahn-Teller effect in the fluorescent level ofMn++in ZnSe and ZnS

Abstract

Uniaxial-stress experiments have been used to analyze the fine-structure lines of the lowest $^{4}T_{1}$ level of ${\mathrm{Mn}}^{++}$ in cubic ZnSe and in cubic ZnS containing stacking faults. We show that the two fine-structure lines due to the cubic centers in ZnSe and ZnS can be interpreted by Ham's model corresponding to a strong Jahn-Teller coupling with $E$ symmetry modes. In both cases, the observed lines correspond to transitions from the $|^{6}A_{1}〉$ fundamental state to the almost degenerate states $|{\ensuremath{\Gamma}}_{7}〉$, $(\frac{3}{\sqrt{10}})|{\ensuremath{\Gamma}}_{8}(\frac{3}{2})〉\ensuremath{-}(\frac{1}{\sqrt{10}})|{\ensuremath{\Gamma}}_{8}(\frac{5}{2})〉$ for the line at lower energy and $|{\ensuremath{\Gamma}}_{6}〉$, $(\frac{1}{\sqrt{10}})|{\ensuremath{\Gamma}}_{8}(\frac{3}{2})〉+(\frac{3}{\sqrt{10}})|{\ensuremath{\Gamma}}_{8}(\frac{5}{2})〉$ for the line at higher energy. The influence of the Jahn-Teller effect on the axial ${\mathrm{Mn}}^{++}$ centers in stacking faults of ZnS is also briefly considered. Finally a comparison is made of the Jahn-Teller effect in the lowest $^{4}T_{1}$ and $^{4}T_{2}$ states of ${\mathrm{Mn}}^{++}$ in ZnS and ZnSe.