Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-27T02:35:08.966Z Has data issue: false hasContentIssue false
  • English
  • Français

Chemical Bonding, Structure, and Morphology of Mg/∝-Al2O3 and MGO / ∝-Al2O3 Interfaces

Published online by Cambridge University Press:  15 February 2011

Yan Yu  and
R.J. Lad
Yan Yu
Affiliation:
Laboratory for Surface Science & Technology, 5764 Sawyer Research Center, University of Maine, Orono, ME 04469
R.J. Lad
Affiliation:
Laboratory for Surface Science & Technology, 5764 Sawyer Research Center, University of Maine, Orono, ME 04469
Get access

Abstract

Ultra-thin films of Mg and MgO were grown on ∝-Al2O3 (1012) surfaces (r-cut sapphire) and studied using reflection high energy electron diffraction (RHEED) and x-ray photoelectron spectroscopy (XPS). When Mg is deposited at 30°C in ultra-high vacuum (UHV), the first monolayer of Mg atoms chemically bonds to the oxygen anions of the sapphire surface. At Mg coverages above a monolayer, a polycrystalline metallic Mg overlayer is formed. Annealing above 250°C in UHV causes the metallic Mg to desorb from the surface. However, annealing above 250°C in 10−6 torr O2 produces a polycrystalline MgO film. This MgO film recrystallizes after annealing in O2 at 900°C for 60 minutes and exhibits a crystallographic orientation of MgO (100) // ∝-Al2O3 (1012). RHEED indicates that the recrystallized MgO layer dewets the sapphire surface and forms islands. When Mg is deposited at 30°C in 10−6 torr O2, a polycrystalline MgO layer is created. This layer also becomes recrystallized and dewets the sapphire surface after extended annealing in O2 at 900°C. No evidence for a MgAl2O4 spinel phase was observed.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 357: Symposium C – Structure and Properties of Interfaces in Ceramics , 1994 , 47
Copyright
Copyright © Materials Research Society 1995

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

[1] Lad, R.J., Surface Review and Letters 2, in press (1995).Google Scholar
[2] Dörre, E. and Hübner, H., Alumina: Processing, Properties, and Applications (Springer-Verlag, New York, 1984).Google Scholar
[3] Wei, P.S.P. and Smith, A.W., J. Vac. Sci. Technol. 9,1209 (1972).Google Scholar
[4] Yu, Yan and Lad, R.J., Mat. Res. Soc. Symp. Proc. 317, 583 (1994).Google Scholar
[5] Antonik, M.D. and Lad, R.J., J. Vac. Sci. Technol. A 10, 669 (1992).Google Scholar
[6] Fuggle, J.C., Watson, L.M., Fabian, D.J. and Affrossman, S., J. Phys. F 5, 375 (1975).Google Scholar
[7] Wagner, C.D. and Biloen, P., Surf. Sci. 35, 82 (1973).Google Scholar
[8] Thermochemical Database, in HSC Chemistry for Windows Software, Version 2.03 (ARSoftware, 8201 Corporate Dr., Landover, MD 20785).Google Scholar
[9] DeSisto, W.J. and Henry, R.L., Appl. Phys. Lett. 56, 2522 (1990).Google Scholar
[10] Huang, R. and A. Kitai, H., Appl. Phys. Lett. 61, 1450 (1992).Google Scholar
[11] Henrich, V.E. and Cox, P.A., The Surface Science of Metal Oxides (Cambridge University Press, Cambridge, 1994), p. 136.Google Scholar