Spin‐polarized electron energy loss spectroscopy study of the initial oxidation of Cr(100)

The electronic excitations of Cr³⁺ magnetic moments at an oxidized Cr(100) surface are studied by spin‐polarized electron energy loss spectroscopy. Sharp loss features are observed due to excitations from the spin‐quartet ground state to doublet states via exchange scattering (predominantly spin flip). The dipole allowed transitions (nonflip) are broadened by crystal field effects. The characteristic Cr³⁺ excitations are observed from the very early stages of oxygen adsorption.