Premium
On the development of long‐range order in ultra‐thin amorphous Al 2 O 3 films upon their transformation into crystalline γ‐Al 2 O 3
Author(s) -
Jeurgens L. P. H.,
Reichel F.,
Frank S.,
Richter G.,
Mittemeijer E. J.
Publication year - 2008
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.2688
Subject(s) - amorphous solid , oxide , x ray photoelectron spectroscopy , materials science , crystallography , electron diffraction , transmission electron microscopy , thin film , epitaxy , high resolution transmission electron microscopy , analytical chemistry (journal) , auger electron spectroscopy , auger , diffraction , chemistry , nanotechnology , optics , nuclear magnetic resonance , metallurgy , atomic physics , physics , layer (electronics) , chromatography , nuclear physics
The changes in the local chemical environments of Al and O ions in ultra‐thin (<1 nm) amorphous Al 2 O 3 films on Al{111} and Al{100} substrates during their transformation into γ‐like‐Al 2 O 3 have been deduced from the corresponding changes in the so‐called Auger parameters for Al and O (as measured using XPS), in combination with structural analysis by high resolution transmission electron microscopy and low‐energy electron diffraction. It is demonstrated that the difference between the O and Al Auger parameters can be employed to monitor the change in polarisation state of the O anions in the oxide film during the amorphous‐to‐crystalline transition. It follows that ( i ) the amorphous‐to‐crystalline transition occurs at higher temperatures (starting at T > 425 K) for the oxide films grown on Al{111} than for the oxide films formed on Al{100} (starting at T < 400 K) and ( ii ) the low‐mismatch (epitaxial) crystalline oxide films on Al{111} possess a higher degree of crystalline order as compared to the high‐mismatch oxide films formed on Al{100}. Copyright © 2008 John Wiley & Sons, Ltd.