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

Abstract

In/Si(111) superstructures formed by the deposition of indium on a √3 × √3-In surface at room temperature were investigated by using a scanning tunneling microscope (STM). The 2×2, ‘striped’, hexagonal √7 × √3 (√7 × √3-hex), and rectangular √7 × √3 (√7 × √3-rec) structures were identified. We demonstrated that the ‘striped’ and the √7 × √3-hex structures were falsely identified as √7 × √3-hex and √7 × √3-rec in a previous report [A. A. Saranin et al., Phys. Rev. B 74, 035436 (2006)]. As in the √7 × √3-hex and √7 × √3-rec structures, a √7 × √3 periodicity was observed in the resolved STM features of the ‘striped’ structure. These three √7 × √3 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 √7 × √3-hex structures in the topographic STM image suggests that the √7 × √3-hex structure consists of double l√ayers of In. This possibility contrasts with recent theoretical predictions of single-layer In for the √7 × √3-hex structure.