Sm-induced reconstructions on Si(1 1 1) surface

Using scanning tunneling microscopy (STM) and low energy electron diffraction (LEED), the surface reconstructions induced by submonolayer Sm adsorption on a Si(1 1 1) have been studied. This system forms a series of metal-induced n × 1 (n = 3, 5, 7,…) reconstructions with increase of Sm coverage on the Si(1 1 1) substrate at elevated temperatures. Our STM results indicate that these reconstructions appear as well-ordered row-like structures. Local mixing of the 3 × 1 and n × 1 unit cells (or stripes) indicates that the atomic models for these phases should be closely related. The atomically resolved STM images reveal a strong bias dependence which determine the relative registry of the Si as well as Sm atoms for these reconstructions. Our results are consistent with the chain-channel models of the row-like structures of the Ca/Si(1 1 1) system as proposed in the literature.