抄録
The atomic structure of the Ca induced Si(111)-(3×2) surface at 300 K has been investigated using X-ray photoelectron diffraction (XPD). After confirming the quality of the single-domain (3×2) surface by LEED, in which weak ×2 streaks were observed likewise the patterns reported in the literature, we have measured the Ca 2p core-level spectra within an azimuthal angle range of ±66°, where 0° corresponds to the direction perpendicular to the Ca chain, and at takeoff angles from 9° to 15° using the Mg Kα line. The experimental XPD patterns showed good agreement with the simulated XPD patterns of the T4 site model, while the simulated XPD patterns of the H3 model do not agree with the experimental results. Taking these results into account, we conclude that Ca atoms are adsorbed on the T4 site at 300 K and thus that the weak ×2 streaks do not result from the presence of two adsorption sites as proposed in the literature. [DOI: 10.1380/ejssnt.2006.166]
