Abstract
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.
Original language | English (US) |
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Pages (from-to) | 38-44 |
Number of pages | 7 |
Journal | Surface Science |
Volume | 586 |
Issue number | 1-3 |
DOIs | |
State | Published - Jul 20 2005 |
Funding
The authors acknowledge financial support from the EMSI program of the National Science Foundation and the US Department of Energy Office of Science (CHE 9810378) at the Northwestern University Institute for Environmental Catalysis as well as the use of X-ray Facilities supported by the MRSEC program of the National Science Foundation (DMR-0076097) at the Materials Research Center at Northwestern University. We would also like to thank Professor Kenneth R. Poeppelmeier of the Northwestern University Department of Chemistry for use of the optical floating zone furnace where the pure synthetic hematite crystals were grown.
Keywords
- Ion response bombardment
- Iron oxide
- Single crystal surfaces
- Surface structure and morphology
- Transmission high energy electron diffraction
ASJC Scopus subject areas
- Condensed Matter Physics
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Materials Chemistry