Magnetic structure of oxidized Fe(001)

The combination of spin-polarization detection with core-level photoemission to give spin-polarized electron spectroscopy for chemical analysis provides new information on the oxidation of an iron surface. During the initial stage of oxidation the predominant phase is of a ferrimagnetic γ-${\mathrm{Fe}}_2$ ${\mathrm{O}}_3$ form. An observed antiferromagnetic coupling of this oxide with the iron substrate is attributed to a superexchange interaction, providing evidence for a possible site-exchange mechanism during the initial oxidation. Annealing transforms this oxide into an antiferromagnetic ${\mathrm{Fe}}_{\mathit{x}}$O form which is also present at the initial stage.