√3 × √3 →6×6 phase transition on the Au/Si(111) surface

The transition between the {}3 ×{} {}3 and 6×{}6 reconstructions of the Au/Si(111) surface is unusual in that, as the Au coverage increases, there is a continuous evolution of the surface structure with Au coverage, rather than a simple change in the relative abundances of two distinct, well-ordered phases. Scanning-tunneling-microscope images show that the {}3 ×{} {}3 structure is broken up into sub-100-{} domains that decrease in size with increasing Au coverage. The 6×{}6 phase can be described as a periodic arrangement of small {}3 ×{} {}3 domains.