Nanostructures growth on the Co-Si(1 1 1) (7×7)R19.1° surface reconstruction

The growth of nanoclusters on a particular Co-Si(1 1 1) surface reconstruction has been investigated by scanning tunnelling microscopy. The Co-Si(1 1 1) (7×7)R19.1° surface reconstruction is obtained after deposit of 0.2 ML of Co on the Si(1 1 1)-7 × 7 surface and heating at 800 K. Under these growth conditions the initial 7 × 7 terraces are entirely reconstructed. One observes for this (7×7)R19.1° periodicity ordered domains which are used as template layer for subsequent deposits. These domains are separated by well-defined boundaries distributed in a uniform way on the surface. Au atoms deposited at room temperature on this reconstructed surface diffuse over the defect-free domains and are trapped in the boundary lines. This leads to the formation of a regular arrangement of Au islands of well-defined size. These islands are distributed uniformly on the surface and present also a homogeneous size distribution.