title: Hartree-Fock study of orbital magnetic moments in 3d and 5f magnets and X-ray magnetic circular dichroism.
abstract: The spin (Ms) and orbital magnetic moments (Mo) of the uranium 5f state in the ferromagnetic compound uranium sulfide (US) and of the cobalt 3d state in various transition-metal superlattices are calculated on the basis of a tight-binding model, in which the intra-atomic f-f or d-d multipole interaction is taken into account using the Hartree-Fock (HF) approximation. The parameters in the model are determined on the basis of available first-principles calculations. For US, the calculated ratio Mo/Ms and magnetic circular dichroism spectrum for U M4,5 absorption are in good agreement with the experimental results. Inclusion of the expectation values of the spin-off-diagonal operators in addition to the number operators in the 5f state is found to be crucially important when describing the 5f magnetic state. A difference in enhancement of Mo of the Co atom between the Co/Pd and Co/Cu superlattices is discussed on the basis of a semi-quantitative calculation, assuming ferromagnetism.
authors.affiliation: Department of Quantum Matter, Hiroshima University, Higashi-Hiroshima, Japan. jo@sci.hiroshima-u.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Jo