The growth of Sm on Si(001) at 600°C was studied by scanning tunneling microscopy. There are two different surface reconstructions: a lower coverage 2×3 phase and a higher coverage 3×2 phase. Sm zigzag chain structures coexist with the 2×3 structure at low coverage. The 3×2 phase coexists with a related c(6×2) phase. At higher coverages, large 3D Sm silicide islands are found.

Holmium deposition on the Si(001) surface at elevated temperature results in the formation of Ho silicide islands coexisting with a Ho reconstructed substrate surface. At metal coverages below a monolayer, most of the islands are highly elongated nanowires. Structural details of both the reconstructions and the nanowires derived from scanning tunneling microscope data are presented. In addition, scanning tunneling spectroscopy shows that the nanowires are more metallic than either the reconstructed surface, or large silicide islands.

This paper presents scanning tunneling microscope images of several rare-earth metal silicides grown on silicon (001). For certain of the metals studied (Dy, Ho), an anisotropy in lattice match with the substrate results in the formation of nanowires. These nanowires have desirable properties such as nanometer lateral dimension, crystalline structure with a low density of defects, and micrometer scale length. Tunneling spectroscopy on the nanowires indicates that they are metallic.