Berlin 2008 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 75: Oxides and Insulators: Epitaxy and Growth
O 75.3: Vortrag
Donnerstag, 28. Februar 2008, 15:45–16:00, MA 042
Thin film growth of Fe2O3 on Ag(111) and Al2O3(0001) — •Maike Lübbe, Alexander M. Gigler, and Wolfgang Moritz — LMU, Department für Geo- und Umweltwissenschaften, Theresienstr. 41, D-80333 München
Hematite, α-Fe2O3, is an interesting and important iron oxide, most notably due to its magnetic and catalytic properties. However, the bulk material is a semiconductor with a wide band gap, Eg = 2.1 eV, which renders electron spectroscopic measurements very difficult.
We therefore grew Fe2O3 thin films on Ag(111), a system similar to Fe2O3 on Pt(111) (see e. g. [1]), which has not been reported up to now. The thin films were grown by MBE at low substrate temperatures, Tsub ≤ 100∘C, in an O + O2 atmosphere, p ≈ 10−7 mbar, using an atomic oxygen source. The samples were characterised by different methods including Auger spectroscopy, XRD, AFM and Raman spectroscopy.
For comparison, we also grew Fe2O3 thin films on Al2O3(0001), a more commonly known system (see e. g. [2]). We had to choose higher substrate temperatures, Tsub ≈ 500∘C, to get reasonable results. Analysis revealed that thin films grown on Al2O3 are much smoother than those grown on Ag.
XRD measurements that will help to figure out structural differences between Fe2O3 thin films grown on Ag(111) or Al2O3(0001) are still in progress.
[1] A. Barbier et al., Phys.Rev. B 72, 245423 (2005)
[2] I. J. Lee et al., J. Vac. Sci. Technol. A 23, 1450 (2005)