The impacts of Sn deposition amount and annealing temperature on the formation of PtSn surface alloys

Abstract Sn/Pt(111) surfaces have been extensively studied by surface sensitive techniques due to their excellent applications in catalysis. However, impacts of Sn deposition amount and subsequent annealing temperature on the surface structure of Sn/Pt(111) still remain unclear. We here investigate growth and surface structures of the Sn/Pt(111) system, particularly in the low Sn coverage and low annealing temperature regimes by scanning tunneling microscopy. We observe Sn atoms on Pt(111) and partially embedded into Pt(111) by submonolayer deposition at room temperature. Most of Sn atoms disappear from the surface and embedded into Pt(111) by annealing up to 650 K, but the surface does not form the ordered structure. In contrast to submonolayer Sn coverage, a p(2 × 2) ordered surface, which is characteristic for Pt 3 Sn(001) lattice, is observed when Sn coverage is increased up to one monolayer and the sample is annealed at 550 K.