| Autor: |
Preobrajenski AB; MAX IV Laboratory, Lund University, 22100 Lund, Sweden., Lyalin A; Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Kita 21 Nishi 10, Sapporo 001-0021, Japan.; Center for Green Research on Energy and Environmental Materials (GREEN), National Institute for Materials Science, Namiki 1-1, Tsukuba 305-0044, Japan., Taketsugu T; Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Kita 21 Nishi 10, Sapporo 001-0021, Japan.; Department of Chemistry, Faculty of Science, Hokkaido University, Kita 10 Nishi 8, Sapporo 060-0810, Japan., Vinogradov NA; MAX IV Laboratory, Lund University, 22100 Lund, Sweden., Vinogradov AS; St. Petersburg State University, St. Petersburg, 198504, Russia. |
| Abstrakt: |
A great variety of two-dimensional (2D) boron allotropes (borophenes) were extensively studied in the past decade in the quest for graphene-like materials with potential for advanced technological applications. Among them, the 2D honeycomb boron is of specific interest as a structural analogue of graphene. Recently it has been synthesized on the Al(111) substrate; however it remains unknown to what extent does honeycomb boron behave like graphene. Here we elucidate the structural and electronic properties of this unusual 2D material with a combination of core-level X-ray spectroscopies, scanning tunneling microscopy, and DFT calculations. We demonstrate that in contrast to graphene on lattice-mismatched metal surfaces, honeycomb boron cannot wiggle like a blanket on Al(111), but rather induces reconstruction of the top metal layer, forming a stoichiometric AlB 2 sheet on top of Al. Our conclusions from theoretical modeling are fully supported by X-ray absorption spectra showing strong similarity in the electronic structure of honeycomb boron on Al(111) and thick AlB 2 films. On the other hand, a clear separation of the electronic states of the honeycomb boron into π- and σ-subsystems indicates an essentially 2D nature of the electronic system in both one-layer AlB 2 and bulk AlB 2 . |
