Analysis of the spin-Hamiltonian parameters for Mn2+ in axial sites of the alkali chlorides and fluorides

The applicability of the superposition model to the quadrupole spin-Hamiltonian parameters of Mn2+ in axial symmetry sites of the alkali chlorides and fluorides is analyzed. In addition, taking advantage of the EPR spectra of Mn2+ in tetragonal sites of RbCl, the fourth-order parameters b04 and b44 have been determined in order to test the applicability of the superposition model not only for the n=2, but also for the n=4 spin-Hamiltonian parameters. It was found that the sign and value obtained in this work, for the intrinsic parameter ?2 of Mn2+ with Cl− ligands, are in good agreement with those estimated by Newman and Siegel from the ?2 value of Eu2+ ions, if the power law exponent of ?2 is taken to be equal to seven.