Thulium induced reconstructions of the Si(001) surface

The initial stages of epitaxial growth of Tm on Si(001) are studied by using scanning tunneling microscopy. Tm induces two kinds of surface reconstructions: 2 × 4 and a striped pseudo 2 × 7 phase. The morphology of the 2 × 4 is similar to the 2 × 4 phase induced by other rare earth metals. The pseudo 2 × 7 phase has some common structural elements with the conventional 2 × 7 phase but shows a broad width distribution. Growth of silicide islands and nanowires is seen at higher metal coverages after post deposition annealing. Differences in behavior with respect to other rare earth metals can be attributed to differences in the stable bulk silicides in this system.