Theoretical studies of the spin Hamiltonian parameters and the local structures for M 2+ (M = Co, Mn, V and Ni) ions in CsMgCl 3

Abstract

The spin Hamiltonian parameters (zero-field splitting D, g factors g ∥, g ⊥ and hyperfine structure constants A ∥, A ⊥) for M 2+ (M = Co, Mn, V and Ni) ions in CsMgCl 3 are studied by using the perturbation formulas of the spin Hamiltonian parameters for 3d n ( n=7, 5, 3, 8) ions in trigonal symmetry based on the cluster approach. In these formulas, the contributions to the spin Hamiltonian parameters from the admixture of d orbitals of the central ions with the p orbitals of the ligands and from the trigonal distortion are included and the parameters related to these effects can be obtained from the optical spectra and the local structures of the studied systems. Based on the studies, it is found that the local trigonal distortion angle β in the M 2+ impurity center is unlike that β H (≈51.71°) in the host CsMgCl 3. The spin Hamiltonian parameters for these divalent ions in CsMgCl 3 are also satisfactorily explained by using the local angle β. The validity of the results is discussed.