Identification of iron oxide phases in thin films grown on Al2O3(0 0 0 1) by Raman spectroscopy and X-ray diffraction

Lübbe, M.; Gigler, Alexander M.; Stark, R.W. and Moritz, Wolfgang (2010): Identification of iron oxide phases in thin films grown on Al2O3(0 0 0 1) by Raman spectroscopy and X-ray diffraction. In: Surface Science, Vol. 604, No. 7-8: pp. 679-685

Abstract

We report on the identification of Fe3O4 (magnetite) and α-Fe2O3 (hematite) in iron oxide thin films grown on α-Al2O3(0 0 0 1) by evaporation of Fe in an O2-atmosphere with a thickness of a few unit cells. The phases were observed by Raman spectroscopy and confirmed by X-ray diffraction (XRD). Magnetite appeared independently from the substrate temperature and could not be completely removed by post-annealing in an oxygen atmosphere as observed by X-ray diffraction. In the temperature range between 400 °C and 500 °C the X-ray diffraction shows that predominantly hematite is formed, the Raman spectrum shows a mixture of magnetite and hematite. At both lower and higher substrate temperatures (300 °C and 600 °C) only magnetite was observed. After post-annealing in an O2-atmosphere of 5 × 10-5 mbar only hematite was detectable in the Raman spectrum.

• Item Type: Journal article
• Faculties: Geosciences > Department of Earth and Environmental Sciences > Crystallography and Materials Science
• Subjects: 500 Science > 550 Earth sciences and geology
• Language: English