Electronic structure of U, Np, Pu impurities in Pd: Self-consistent spin-polarized relativistic calculations

Abstract

The original fully relativistic spin-polarized technique for investigation of the electronic structure of isolated impurities in crystals is presented. The method starts with classical spin-polarized relativistic multiple-scattering formalism and uses two additional approximations: the atomic-sphere approximation and the Taylor expansion for energy dependence of Dirac-like solutions inside the Wigner-Seitz sphere. Linearized expressions for spin-polarized multiple-scattering parameters (such as the single-site t-matrix, the Green function of the crystal and others) are obtained. The method developed is applied for the self-consistent spin-polarized relativistic calculations of the electronic structure and magnetic properties of U, Np, Pu impurities in palladium. The total magnetic moments of impurity atoms appear to be zero or very low for all the systems considered. Different from nonmagnetic U impurities, Np and Pu atoms acquire large static spin magnetic moments, which are almost completely compensated by the orbital contributions induced due to the spin-orbit coupling and aligned in the opposite direction. The comparison with the experimental data available is made and discussed.