Chemical bonding, structure, and morphology of Mg/{alpha}-Al{sub 2}O{sub 3} and MgO/{alpha}-Al{sub 2}O{sub 3} interfaces
Conference
·
OSTI ID:94035
- Univ. of Maine, Orono, ME (United States). Lab. for Surface Science and Technology
Ultra-thin films of Mg and MgO were grown on {alpha}-Al{sub 2}O{sub 3} (10{bar 1}2) 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{sup {minus}6}torr O{sub 2}produces a polycrystalline MgO film. This MgO film recrystallizes after annealing in O{sub 2} at 900 C for 60 minutes and exhibits a crystallographic orientation of MgO (100) {vert_bar}{vert_bar} {alpha}-Al{sub 2}O{sub 3} (10{bar 1}2). RHEED indicates that the recrystallized MgO layer dewets the sapphire surface and forms islands. When Mg is deposited at 30 C in 10{sup {minus}6} torr O{sub 2}, a polycrystalline MgO layer is created. This layer also becomes recrystallized and dewet the sapphire surface after extended annealing in O{sub 2} at 900 C. No evidence for a MgAl{sub 2}O{sub 4} spinel phase was observed.
- DOE Contract Number:
- FG02-90ER45417
- OSTI ID:
- 94035
- Report Number(s):
- CONF-941144--; ISBN 1-55899-258-8
- Country of Publication:
- United States
- Language:
- English
Similar Records
Heteroepitaxial growth of MgO films on NiO(100) single crystal surfaces
Growth and stability of MgO/NiO multilayered films on single crystal NiO(100)
Effect of annealing atmosphere on the contact resistivity, superconductivity, and phase transformation in the Al/BiSrCaCuO system
Conference
·
Fri Sep 01 00:00:00 EDT 1995
·
OSTI ID:94051
Growth and stability of MgO/NiO multilayered films on single crystal NiO(100)
Book
·
Thu Oct 31 23:00:00 EST 1996
·
OSTI ID:392203
Effect of annealing atmosphere on the contact resistivity, superconductivity, and phase transformation in the Al/BiSrCaCuO system
Journal Article
·
Sat Nov 30 23:00:00 EST 1991
· Journal of the Electrochemical Society; (United States)
·
OSTI ID:5070437