Impurity stabilized near-surface phase on ion bombarded α-Fe2O3(0 0 0 1)

Following Ar+ ion bombardment, an epitaxial spinel phase forms on the near-surface of hematite specimens that contain impurity species. This near-surface spinel phase can readily be distinguished in a transmission electron diffraction pattern, and is stable under a much broader range of oxygen partial pressures than has been previously observed in the literature. Conversely, hematite samples which are impurity free show no evidence of an epitaxial spinel phase. Regardless of the impurity concentration, samples annealed at high temperature in oxygen-rich environments show (1 × 1) diffraction patterns indicative of a bulk hematite termination.