Phonon‐induced hyperfine interactions for 6S‐state ions in tetrahedral symmetry: Mn2+ in ZnS and ZnSe

On the basis of a point‐charge model according to the theory of Šimánek and Orbach equations are derived for the temperature dependence of the hyperfine coupling constant of 6S‐state ions in tetrahedral symmetry without the approximation of small wave vectors for lattice phonons. Acoustical and optical phonons of the entire phonon spectrum are taken into consideration. The temperature functions calculated are compared with the measured values for ZnS:Mn2+ and ZnSe:Mn2+. The curves obtained very well correspond to the temperature dependence measured if always one parameter is taken from the experiment. The calculations, however, supply parameters which deviate by more than one order of magnitude from the experimental ones. The reasons for these deviations are particularly involved in the applied point‐charge model.