Epitaxial growth of silicene on atomically flat ultra-thin Ag(111) films was investigated using scanning tunneling microscopy. The Ag films were prepared by low-temperature deposition of Ag on Si substrates, followed by soft annealing at room temperature. Patchy 4 × 4, √13 × √13, √7 × √7, and 2√3 × 2√3 silicene domains were nucleated on regions that were one monolayer lower than the pristine Ag surface after the initial morphological change had been completed. On the first-layer silicene containing the above domains, two types of √3 × √3 silicene domains (√3 × √3-α and β) were formed in the second layer. A bias voltage-independent Moiré pattern was observed for the √3 × √3-α silicene, and a bias voltage-dependent standing wave pattern for the √3 × √3-β silicene. The √3 × √3-β silicene had a dispersion relation that could be fitted using a linear function, although the resulting Fermi velocity was twice as large as the expected value. 2 New J. Phys. 16 (2014) 095004 J Sone et al New J. Phys. 16 (2014) 095004 J Sone et al

The growth of Si layers on Si(111)√3×√3-Ag substrates was studied for coverages of up to a few mono-layers. Atomically flat islands were observed to nucleate in the growth at 570 K. The top surfaces of the islands were covered in Ag atoms and exhibited a √3×√3 reconstruction with the same surface state dispersions as Si(111)√3×√3-Ag substrates. These results indicate that the Ag atoms on the substrate always hop up to the top of the Si layers.

We studied the growth of Si at the surface of epitaxial graphene on 6H-SiC(0001). Characteristic flower-like islands with a thickness of 2 to 3 nm nucleated during the growth from 290 to 420 K. The islands became featureless in growth at higher temperatures. The growth was predominantly governed by diffusion-limited aggregation. The diffusion energy was evaluated to be 0.21 eV from the temperature-dependent decrease in the density of the islands.

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