Structure determination of flat honeycomb Bi grown on Ag(111)

TL;DR

This study investigates the structure of flat honeycomb bismuthene on Ag(111) using LEED and DFT, revealing temperature-dependent structural transformations and stability of specific configurations relevant for topological properties.

Contribution

It provides detailed structural characterization of flat bismuthene on Ag(111), including temperature effects and surface segregation, advancing understanding of 2D topological bismuthene.

Findings

0.5 ML Bi forms ultraflat honeycomb lattice at ~120 K

Flat bismuthene remains stable at room temperature in Mn/Bi/Ag(111)

Bi surface segregation induced by Mn deposition

Abstract

Honeycomb bismuthene structures on Ag(111) were investigated using low-energy electron diffraction (LEED) and density functional theory. LEED I(V) analysis revealed that 0.5 monolayer (ML) of Bi forms an ultraflat honeycomb lattice with negligible buckling at ~120 K, which transforms into other structures upon warming to room temperature. A similar flat bismuthene structure also forms in Mn/Bi/Ag(111), which remains stable even at room temperature. Mn deposition on $(p\times \sqrt{3})$-rect Bi/Ag(111) induces Bi surface segregation, as confirmed by X-ray photoelectron spectroscopy, resulting in a p$(2\times2)$ honeycomb bismuthene. The detailed structural investigation provides fundamental insights into the characterization of two-dimensional topological properties of bismuthene grown on Ag(111).