While a perfect hcp (0001) surface has three-fold symmetry, the diffraction patterns commonly obtained are six-fold symmetric. This apparent change in symmetry occurs because on a stepped surface, the atomic layers on adjacent terraces are rotated by 180 degrees. Here we use a Low-Energy Electron Microscope to acquire the three-fold diffraction pattern from a single hcp Ru terrace and measure the intensity-vs-energy curves for several diffracted beams. By means of multiple scattering calculations fitted to the experimental data with a Pendry R-factor of 0.077, we find that the surface is contracted by 3.5(+-0.9) at 456 K.
@article{arxiv.cond-mat/0601475,
title = {Determining the structure of Ru(0001) from low-energy electron diffraction of a single terrace},
author = {J. de la Figuera and J. M. Puerta and J. I. Cerda and F. El Gabaly and K. F. McCarty},
journal= {arXiv preprint arXiv:cond-mat/0601475},
year = {2007}
}
Comments
10 pages, 4 figures. Corrected some typos, added more details. Accepted for publication in Surface Science (Letters)