Effect of Coulomb Interaction on the X-Ray Magnetic Circular Dichroism Spin Sum Rule in 3<i><i>d</i></i>Transition Elements

Abstract

A deviation from the X-ray magnetic circular dichroism (MCD) spin sum rule, which is derived assuming well separated core spin-orbit multiplets in the final state of X-ray absorption, is calculated for the L 2,3 edge in the magnetized Ni, Co, Fe and Mn ions on the basis of an atomic model including the full multiplet and the crystal field with O h symmetry. Due to the Coulomb interaction between electrons, which mixes the so-called L 3 and L 2 regions with each other, it is found that the deviation can be ∼10 percent for the former three ions, while for Mn 2+ it amounts to more than 30 percent. A list of the deviations for various ionic states for the above elements is presented, which may serve as a correction factor in the estimation of expectation values of magnetic quantities from MCD data.