Properties of a 5T2 in iron (II) under the action of arbitrary‐symmetry ligand fields and spin‐orbit coupling I. On the quadrupole splitting

Abstract

AbstractThe quadrupole splitting of the ground state 5T2 of high‐spin iron(II), split by a ligand field and spin–orbit coupling, has been treated. It is shown to depend up to a constant factor only on the energy splittings Δ1 and Δ2 of the orbital states, the spin–orbit coupling constant λ, and the temperature, but not on the orbital eigenstates of the ligand field. The well‐known method of fitting ligand field parameters from the temperature dependence of the quadrupole splitting now can be applied even in the case of low symmetry ligand fields without having trouble with too many parameters. From the temperature dependence of the quadrupole splitting it can be only differentiated between cubic (Oh, Td, …), axial (D3, D4, D2d, …) or lower symmetry (D2, C2v, C2, …, C1) ligand fields. A formula for calculating the components of the EFG in low symmetry ligand fields is derived.