SUPERPOSITION MODEL ANALYSIS OF THE CUBIC SPIN-HAMILTONIAN PARAMETERS FOR MN2+ AND FE3+ IN THE ALKALINE-EARTH OXIDES, FLUOROPEROVSKITE, AND II-VI-COMPOUNDS

An analysis, in terms of Newman’s superposition model, of the cubic spin–Hamiltonian parameters for divalent manganese and trivalent iron in fluoroperovskite and II–VI compounds is presented. Values for the intrinsic parameter ?4 and for the power-law exponent t4 of Mn2+ with F−, S2−, Se2−, and Te2− ligands are reported for the first time. In addition, values are obtained for ?4 of Fe3+ surrounded by sulfur, selenium, and tellurium as ligands. Also, a re-evaluation of the previously reported power-law exponent t4 is made for Mn2+ with oxygen ligands, taking into account the local distortion around the impurity ion. Using the superposition model, the interaction distances between the Mn2+–F− and the Fe3+–F− pairs in the fluoroperovskite compounds KMgF3, KZnF3, KCaF3, RbCdF3, RbCaF3, and TlCdF3 are determined. This allowed us to make theoretical calculations of the value for the transferred hyperfine parameters As and Ap for both Mn2+ and Fe3+ in these compounds. A close relationship between the value of the intrinsic parameter ?4 with the ligand polarizability and the covalency of the bond as well, is proposed for Mn2+ and Fe3+ with F−, O2−, Cl−, S2−, Se2−, and Te2− as ligands. © 1979, American Institute of Physics. All rights reserved.