Surface X-ray Diffraction Study of the Metal-Insulator Transition on the Si(553)-Au Surface

We have studied the metal-insulator transition near room temperature on the Si(553)-Au surface with surface X-ray diffraction. Diffraction intensities due to the ×2 superstructure developing in the transition were collected at 86 K. The Patterson map calculated from the experimental intensities shows that only a few atoms are involved in the transition. The atoms are displaced mostly in the surface plane. The temperature dependence of the intensity and width of one reflection due to the low temperature superstructure was measured as well. The changes in the intensity of this reflection below the transition temperature are consistent with the predictions by the mean-field theory for a Peierls transition at 336 K. The changes of the intensity above the transition temperature and the temperature dependence of the width of the reflection can be explained by the influence of defects. [DOI: 10.1380/ejssnt.2008.281]