Investigation of root 7 x root 3 structures grown on In/Si(111) surfaces at room temperature

摘要

In/Si(111) superstructures formed by the deposition of indium on a ae3 x ae3-In surface at room temperature were investigated by using a scanning tunneling microscope (STM). The 2x2, 'striped', hexagonal ae7 x ae3 (ae7 x ae3-hex), and rectangular ae7 x ae3 (ae7 x ae3-rec) structures were identified. We demonstrated that the 'striped' and the ae7 x ae3-hex structures were falsely identified as ae7 x ae3-hex and ae7 x ae3-rec in a previous report [A. A. Saranin et al., Phys. Rev. B 74, 035436 (2006)]. As in the ae7 x ae3-hex and ae7 x ae3-rec structures, a ae7 x ae3 periodicity was observed in the resolved STM features of the 'striped' structure. These three ae7 x ae3 structures formed at room temperature were shown to be identical to the corresponding In-induced phases formed at high temperature. The apparent height difference between the 'striped' and the ae7 x ae3-hex structures in the topographic STM image suggests that the ae7 x ae3-hex structure consists of double laeayers of In. This possibility contrasts with recent theoretical predictions of single-layer In for the ae7 x ae3-hex structure.