Presentation Information
[2F02]Accuracy of hydrogen structure on (2x2)-2H/Ni(111) surface by RHEED
*Takaaki Kawamura1,3, Yuki Fukaya2, Takahiro Ozawa1, Shohei Ogura3, Katsuyuki Fukutani1,2 (1. Institute of Industrial Science, University of Tokyo, 2. Advanced Science Research Center, Japan Atomic Energy Agency, 3. School of Engineering, Tokyo Denki University)
We report that the structure of the (2x2)-2H/Ni(111) surface was determined with good accuracy by using RHEED. We measured 7 rocking curves at the [1,0,-1] azimuth, 5 curves at the [2,-1,-1] azimuth, and 3 curves at the azimuth 1° off from the [1,0,-1] axis. Comparing the measured and calculated rocking curves, we found that one H atom is located at the hcp-hollow site and the other at the fcc-hollow site, with one Ni atom in the top layer displaced vertically downward. This results in a buckling in the top layer. These two results are consistent with those reported by Hammer et al. by using LEED. Introducing an upward vertical displacement of the Ni atom in the second layer and horizontal displacements of the three Ni atoms in the top layer resulted in a better agreement between the measured and calculated curves. This result demonstrates that RHEED can accurately reveal the structure of adsorbed H and the reconstructed Ni substrate.