Massively Cooperative Adsorbate-Induced Surface Restructuring and Nanocluster Formation

摘要

The reconstructions seen at certain clean metal surfaces,such as the Au{111) "herringbone" and Pt(100) "hex" phases,are typically lifted by adsorption of small molecular species,with the outermost metal atom layer reverting to (1x1).The restructuring process may have important implications for kinetics.In CO adsorption on Pt{100},for example,an experimentally determined nonlinear power law in the growth rate of (1 x l)-CO islands from the hex phase implies a "cooperative effect",in which four CO molecules must coincide for concerted restructuring to (1 x 1) of a small patch comprising about 8-10 Pt atoms.