IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Surface Science Friday Sessions
       Session SS3-FrM

Paper SS3-FrM6
Structure Analysis of Oxygen-adsorbed and Annealed W(001) Surface at Liquid Nitrogen Temperature

Friday, November 2, 2001, 10:00 am, Room 122

Session: Clean and Adsorbed Surfaces
Presenter: H. Yamazaki, The University of Electro-Communications, Japan
Authors: S. Kamimizu, The University of Electro-Communications, Japan
K. Hara, The University of Electro-Communications, Japan
T. Kokubun, The University of Electro-Communications, Japan
T. Haga, The University of Electro-Communications, Japan
K. Sakamoto, The University of Electro-Communications, Japan
H. Yamazaki, The University of Electro-Communications, Japan
Correspondent: Click to Email
The structure of oxygen-adsorbed and annealed W (001) surface was investigated at the liquid nitrogen temperature. We have already reported the structure of this system at the room temperature (H. Yamazaki, et al., Surf. Sci. 447 (2001) 174). The result obtained previously is that the 2x1 LEED pattern was observed, and the most probable calculated structure consists of missing rows of W and double rows of oxygen atoms adsorbed on one of two three-hold hollow sites of W (011) facet which was appeared by losing the W-atoms. The Pendry R-factor for this structure is 0.25. As the energy difference between those two three-hold hollow sites is so small as 12 meV by a rough calculation, the adsorbed oxygen atoms should occupy those two sites by a certain ratio. It is considered that the oxygen atoms fall into the more stabilized adsorption site when the sample is cooled down to the liquid nitrogen temperature. Then the experiment was performed on the same sample at the liquid nitrogen temperature, and the most probable structure was determined with the Pendry R-factor of 0.20. The structure agrees well with that at the room temperature within an error. We will present the experimental and calculating procedure, and the most probable structure compared with that at the room temperature.