Hexagonal indium double layer onSi(111)−7×3

Indium coverage of the Si(111)- 7×3 -In surface

“…For 2.4 ML we found that "rect" is the most stable configuration with formation energy~74 meV per unit cell lower than the "hex" phase. Our result agrees with a previous first-principles study by Park and Kang [23], which predicted that the "rect" model is 0.05 eV more stable than the "hex" one. This indicates that In on Si(111)-√7 × √3 forms a double layer structure with 2.4 ML coverage, and only the "rect" phase exists.…”

“…5(b) and 5(c)) between the In-In (2.40 Å for "rect" and 2.45 Å for "hex") and In-Si layers (2.58 Å for "rect" and 2.59 Å for "hex") are in close agreement with the values reported by Park and Kang [23], namely 2.42/2.60 Å for "rect" and 2.47/2.61 Å for "hex". We found, however, a significant difference in height of the top-layer In atoms in the "hex" phase when compared to the "rect" phase: while in the "rect" configuration the heights of the top-layer In atoms differ from each other by less than 0.05 Å, in the "hex" configuration the difference in height ranges from 0.05 to 0.20 Å.…”

“…The "hex" phase as proposed by Park and Kang in Ref. [23] is unlikely to form for energetic reasons (see below), and the two different STM images reported in Figs. 2(b) and 2(c) of Ref.…”

“…For coverages higher than 1.8 ML we can identify the "rect" and the "hex" models proposed in Ref. [23]; their formation energies are indicated in Fig. 5(a) by blue triangles and black squares, respectively.…”

“…However, their In coverages and hence atomic configurations are still controversial. The coverages are reported to be either close to a single In layer (1.0-1.2 ML) or close to a double layer (2.4 ML) for both "hex" and "rect" phases in several literature reports [19][20][21][22][23][24].…”