Single-Layer of Bi<sub>1–<i>x</i></sub>Sb<sub><i>x</i></sub> Grown on Ag(111)

In\nthis work, we report the growth of a mixed Bi<sub>1–<i>x</i></sub> Sb<sub><i>x</i></sub> single layer on\nthe Ag(111) surface with various stoichiometries. The atomic geometry\nhas been thoroughly investigated by low-energy electron diffraction,\nscanning tunneling microscopy, and X-ray photoelectron spectroscopy\nexperiments, as well as calculations based on density functional theory.\nWe first determined that the Sb/Ag(111) system for coverages below\n2/3 monolayer behaves similarly to the Bi/Ag(111) system, with a dealloying\ntransition to a rectangular (3 × √3) phase when the Sb\ncoverage exceeds 1/3 monolayer. We found two alternative preparation\nstrategies to obtain a mixed Bi<sub>1–<i>x</i></sub> Sb<sub><i>x</i></sub> layer: sequential deposition and\nsimultaneous deposition of Bi and Sb. In the first case, one of the\nelements is deposited on a completely covered surface alloy of the\nother element. The obtained phase corresponds to a single mixed BiSb\nlayer free of Ag atoms, forming a rectangular (3 × √3)\nstructure. The simultaneous deposition strategy yields the same structure\nbut offers the significant advantage of enabling controlled variation\nof the stoichiometry. The obtained mixed Bi–Sb phase has a\nlateral atomic arrangement very similar to the one in the nonalloyed\nphase observed for Sb on Ag(111), with Sb and Bi atoms distributed\ndisorderly, and presents a significant vertical corrugation, promising\nconsiderable Rashba effects.