CORRELATION-FUNCTION OF ADSORBED AU CHAIN ON SI(111) SURFACE

The surface structure of Au-adsorbed Si(111)-5x2 with short-range orde r has been observed through STM measurements. Particularly, the one-di mensional chains consisting of adsorbed Au atoms are clearly observed. A one-dimensional lattice model is constructed for this chain, with r epulsive interactions and some assumed irregularity corresponding to S TM observation. The theoretical positional correlation function of the adsorbed Au is obtained by a Monte Carlo simulation with fitting para meters of the repulsive interaction and of the irregularity of the exp erimental positional correlation function. Almost complete fitting is obtained, from which reasonable values of the repulsive interaction an d concentration of the irregularity are obtained. A rigorous analysis is also made of another one-dimensional model to describe the inter-ch ain correlation on this surface, and is compared with experimental fin dings.