Theoretical Investigation of the Spin Hamiltonian Parameters for the Tetragonal [Fe(CN)<sub>4</sub>Cl<sub>2</sub>]<sup>5–</sup> Complex in NaCI

Abstract

The Spin Hamiltonian Parameters (the G Factors and the Superhyperfine Parameters) for the Tetragonal [Fe(CN)4Cl2]5- Complex in Nacl Are Theoretically Investigated from the Perturbation Formulas of these Parameters for a Low Spin (S=1/2) 3d7 Ion in Tetragonally Elongated Octahedra. this Impurity Center Is Attributed to the Substitutional Fe2+ (in the Form of [Fe(CN)6]4–) on Host Na+ Site Reduced by Capturing One Electron during the X-Ray Irradiation Process, with the Two Axial Ligands CN– Replaced by Two Cl–. since the Crystal Fields of the Axial Ligands Cl– Are Weaker than those of the Perpendicular Ligands CN–, the [Fe(CN)4Cl2]5- Complex Exhibits a Tetragonally Elongated Octahedron. this System Shows the Low Spin S=1/2 of the Strong Crystal Field Case, which Is Unlike the High Spin S=3/2 of the Weak and Intermediate Crystal Field Case for Fe+ in Conventional Chlorides. the Theoretical Spin Hamiltonian Parameters Are in Reasonable Agreement with the Experimental Data, and the Results Are Discussed.