Open AccessLEEM STUDIES OF TWO-DIMENSIONAL OXIDATION ON W(110) SURFACE
Author(s) -
Cai Qun,
Michael S. Altman
Publication year - 1997
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.46.1048
Subject(s) - chemisorption , superstructure , low energy electron diffraction , electron diffraction , low energy electron microscopy , diffraction , materials science , oxygen , adsorption , surface (topology) , crystallography , chemical physics , electron microscope , physics , optics , chemistry , geometry , thermodynamics , mathematics , quantum mechanics
With increasing coverage,the adsorption of oxygen on W(110) surface can be- subdivided into chemisorption,two-dimensional oxidation and bulk oxidation. In this work,the new imaging technique low energy electron microscopy (LEEM) was used to investigate the two-dimensional oxidation on W(110) surface. With increasing O coverage,the low energy electron diffraction patterns change from (1×1) to p(2×1) structure,and then into p(2×2) with complex diffraction satellites. Using dark field LEEM mode,we have imaged the fractional spots near (00) beam. It was found that there were two kinds of regions with opposite contrast on the surface,i.e. the oxygen superstructure domains with different orientations. The distribution of these domains was related to surface defects,especially to surface steps. It was also indicated that the temperature played a very important role for surface oxidation.