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Auger spectral shape analysis of Sc‐O/W(100) system during phase transition at high temperature
Author(s) -
Nakanishi Y.,
Nagatomi T.,
Takai Y.
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.2996
Subject(s) - auger electron spectroscopy , auger , chemistry , stoichiometry , analytical chemistry (journal) , transition metal , spectral line , desorption , oxygen , diffusion , phase transition , phase (matter) , electron spectroscopy , substrate (aquarium) , crystallography , x ray photoelectron spectroscopy , atomic physics , adsorption , nuclear magnetic resonance , physics , biochemistry , organic chemistry , chromatography , astronomy , quantum mechanics , nuclear physics , thermodynamics , catalysis , oceanography , geology
The Auger spectral shape analysis of the Sc‐O/W(100) system was performed in order to investigate the chemical state of surface Sc atoms during the phase transition at high temperatures. The measured Sc‐LMM Auger electron spectroscopy (AES) spectra during the phase transition were reproduced by a liner combination of reference spectra obtained from metallic and oxidized Sc thin films on a W(100) substrate. The results revealed that Sc–O complexes on the (1 × 1)‐Sc‐O/W(100) surface are oxidized up to stoichiometry close to Sc 2 O 3 immediately after starting oxygen exposure and diffuse into bulk W(100) during the transition from the (1 × 1)‐ to (2 × 1)‐(1 × 2)‐Sc‐O/W(100) surfaces at 1500 K. It was also found that the Sc–O complexes existing in bulk W(100) segregate to the (2 × 1)‐(1 × 2)‐Sc‐O/W(100) surface at the beginning of the transition from the (2 × 1)‐(1 × 2) to (1 × 1)‐Sc‐O/W(100) surfaces. The following desorption of surface oxygen atoms and the reconstruction of the Sc–O complexes result in the formation of the (1 × 1) structure. The present results confirmed that the diffusion and surface segregation of Sc–O complexes play an important role in determining surface properties of the Sc‐O/W(100) system. Copyright © 2008 John Wiley & Sons, Ltd.