Observation of Spin-Polarized Electron Levels in Ferrites

Measurement of spin polarization of photoelectrons from Fe₃{O}₄$ (MAG) and ${Li}0.5Fe2.5{O}₄$ (LIF) up to ${}{ω}=11$ eV shows that $B$-site $3d$ levels are higher in energy than $A$-site $3d$ levels. In MAG, unpolarized $2p$ electrons are not emitted up to 11 eV. Existing energy diagrams of MAG do not agree fully with the results. As a direct consequence of Hund's rule, the polarization spectra of MAG and LIF are very different because of the presence of Fe²⁺ in MAG.