Electron elastic scattering off a spin-polarized Cr atom

Abstract

Electron elastic scattering off a spin-polarized Cr($...3{d}^{5}4{s}^{1}$, ${}^{7}S$) atom is theoretically studied in the region of electron energies up to 15 eV using both a one-electron ``spin-polarized'' Hartree-Fock approximation and a multielectron spin-polarized random-phase approximation with exchange. It is found that scattering phase shifts of oppositely spin-polarized incoming electrons and corresponding cross sections of the scattering reactions significantly differ from each other, in general, even without accounting for spin-orbit interaction. This is shown to be associated with the presence of two semifilled $3{d}^{5}$ and $4{s}^{1}$ subshells in the Cr configuration which induce considerably different exchange in the interaction of oppositely spin-polarized incoming electrons with the atom target. The importance of electron correlation in the ${e}^{\ensuremath{-}}+\mathrm{Cr}$ elastic-scattering process is revealed. Moreover, correlation is shown to induce strong differences between scattering of oppositely spin-polarized electrons off Cr. A physically transparent interpretation for the latter is provided.