AES, XPS, and TDS study of the adsorption and desorption of NH3 on ultra-thin chromium oxide films formed on chromium single crystal surfaces

Authors
Ma, H Berthier, Y Marcus, P
Citation
H. Ma et al., AES, XPS, and TDS study of the adsorption and desorption of NH3 on ultra-thin chromium oxide films formed on chromium single crystal surfaces, APPL SURF S, 153(1), 1999, pp. 40-46
Citations number
39
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science","Material Science & Engineering
Journal title
APPLIED SURFACE SCIENCE
ISSN journal
01694332 → ACNP
Volume
153
Issue
1
Year of publication
1999
Pages
40 - 46
Database
ISI
SICI code
0169-4332(199912)153:1<40:AXATSO>2.0.ZU;2-Y
Abstract
Ultra-thin films of Cr2O3 have been produced by oxidation of Cr(110) surfac es in O-2 (pO(2) = 3 X 10(-8) mbar) at 190 degrees C. The adsorption and de sorption of NH3 on the thin Cr2O3 films have been studied by LEED, AES, XPS , and TDS. The kinetics of ammonia adsorption was investigated by AES and a dsorbed NH3 states on chromium oxide surfaces were identified by XPS. After exposure to NH3, N 1s signals were observed at 398.6 and 400.7 eV. These r esults were interpreted by the existence of two types of adsorbed species r esulting from the interaction of NH3 with acid sites of the chromium oxide surface. Accordingly, two desorption peaks corresponding to NH2 and NH3 wer e observed by TDS (at 150 degrees C). (C) 1999 Elsevier Science B.V. All ri ghts reserved.