fig1

Figure 1. LEED Patterns and AES spectrum are reported in (A-E). (A) LEED pattern from: Si(111)7 × 7; (B) LEED pattern from Si(111)√3 × √3R30°-Bi β-phase; (C) LEED pattern from 1 ML Si / Si(111)√3 × √3R30°-Bi; (D) LEED pattern from 4 MLs Si/Si(111)√3 × √3R30°-Bi. The red rhombus in (A) indicates the (1 × 1) unit cell of Si(111), while the yellow one indicates the 7 × 7 -Si surface reconstruction. The blue unit cell in (B-D) represents the √3 × √3R30° of Bi on Si and that of 1 and 4 MLs of silicon grown on top of bismuth. The LEED patterns were collected at primary energy, EP, of 43.2, 34.2, 28.8, and 29.0 eV, respectively; (E) AES from Si(111)√3 × √3R30°-Bi β-phase, and 4 MLs Si/Si(111)√3 × √3R30°-Bi interface. The Si LVV and Bi NOO Auger transitions are marked. LEED: Low energy electron diffraction; AES: Auger electron spectroscopy; ML: monolayer.