Formation and coalescence of surface domains introduced by metal deposition on a Si(111) surface

By depositing sub-monolayer Au atoms onto a heated and slightly misaligned Si(111)-(7 × 7) surface, (5 × 2) stripes form on the upper step edges of terraces. Upon further heating, most of the terraces transform into either Au-free (7 × 7) terraces or fully reconstructed (5 × 2) terraces. By analyzing the distance distribution between neighboring (5 × 2) terraces, we have found the existence of an optimal distance between (5 × 2) terraces. This optimal distance, controllable via the Au coverage, can be explained by the minimization of long-range strain relaxation energy for a system consisted of alternating domains. The ability of tuning surface domain structure through metal deposition provides a new way of manipulating surface morphology in the nanometer-scale range.