IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Surface Science Monday Sessions
       Session SS2-MoP

Paper SS2-MoP7
Theoretical Analysis of Short Range Order of Au/Si(100) 5x3.2 Structure

Monday, October 29, 2001, 5:30 pm, Room 134/135

Session: Surfaces and Interfaces Poster Session
Presenter: Y. Yagi, Okayama University of Science, Japan
Authors: Y. Yagi, Okayama University of Science, Japan
K. Kakitani, Okayama University of Science, Japan
H. Kaji, Okayama University of Science, Japan
A. Yoshimori, Okayama University of Science, Japan
Correspondent: Click to Email
It is known that the metal adsorbed semiconductor surfaces show various characteristic structures. One of them is the Au adsorbed on Si(100) surface. According to the recent experimental results by STM and LEED, this system shows the 5x3.2 structure.@footnote 1-4@ Au adsorbates and Si substrate atoms form the 5x3 structure. This structure is made up with the "band" structure along the direction of 3 times and the "band" structures arrange with 5 times period in the perpendicular direction. The STM results indicate that the 5x3.2 structure seems to be formed by protrusions called "wall" in the topmost layer on the 5x3 structure. We describe this system by the lattice gas model for adsorbates (adatoms) in the topmost layer on the 5x3 structure with semi-long ranged repulsive interaction and short ranged attractive interactions, assuming that the protrusion is formed by the adsorbate (adatom), and perform Monte Carlo simulation. We obtain the two adsorbate positional correlation functions and the structure factor of this surface system. The obtained theoretical results are compared with experimental ones, in particular, the correlation function obtained from the STM images. Our results reproduce experimental features semi-quantitatively. The degree of ordering in the 3.2 times period does not seem perfect in the STM images and it may be a structure with short range order. The ratio of interactions with temperature and the most probable interaction ratios are determined by the comparison. @FootnoteText@ @footnote 1@X. F. Lin, K. J. Wan, J. C. Glueckstein and J. Nogami, Phys. Rev. B47, (1993) 3671. @footnote 2@G. Jayaram and L. D. Marks, Surf. Rev and Lett., 2 (1995) 731. @footnote 3@H. Minoda, K. Yagi, F.-J. Meyer zu Heringdorf, A. Meier, D. Kahler, and M. Horn von Hoegen, Phys. Rev. B59, (1999) 2363. @footnote 4@R. Hild, F.-J. Meyer zu Heringdorf, P. Zahl and M. Horn-von Hoegen, Surf. Sci. 454-456 ( 2000) 851. .