2D Tl–Pb compounds on Ge(1 1 1) surface: atomic arrangement and electronic band structure. (15th November 2016)

• Record Type: Journal Article
• Authors: Gruznev, D V; Bondarenko, L V; Tupchaya, A Y; Eremeev, S V; Mihalyuk, A N; Chou, J P; Wei, C M; Zotov, A V; Saranin, A A
• Is Part Of: Journal of physics. Volume 29:Number 3(2017)
• Publication Date: 2016-11-15
• Subjects: atom-solid interaction -- 2D layer -- STM -- ARPES -- DFT calculations -- electronic structure; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/0953-8984/29/3/035001
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: Structural transformations and evolution of the electron band structure in the (Tl, Pb)/Ge(1 1 1) system have been studied using low-energy electron diffraction, scanning tunneling microscopy, angle-resolved photoelectron spectroscopy and density functional theory calculations. The two 2D Tl–Pb compounds on Ge(1 1 1), 3 × 3 -(Tl, Pb) and 3 × 3 -(Tl, Pb), have been found and their composition, atomic arrangement and electron properties has been characterized. The (Tl, Pb)/Ge(1 1 1) 3 × 3 compound is almost identical to the alike (Tl, Pb)/Si(1 1 1) 3 × 3 system from the viewpoint of its atomic structure and electronic properties. They contain 1.0 ML of Tl atoms arranged into a honeycomb network of chained trimers and 1/3 ML of Pb atoms occupying the centers of the honeycomb units. The (Tl, Pb)/Ge(1 1 1) 3 × 3 compound contains six Tl atoms and seven Pb atoms per 3 × 3 unit cell (i.e. ̃0.67 ML Tl and ̃0.78 ML Pb). Its atomic structure can be visualized as consisting of Pb hexagons surrounded by Tl trimers. The (Tl, Pb)/Ge(1 1 1) 3 × 3 and (Tl, Pb)/Ge(1 1 1) 3 × 3 compounds are metallic and their band structures contain spin-split surface-state bands. By analogy with the (Tl, Pb)/Si(1 1 1) 3 × 3, these (Tl, Pb)/Ge(1 1 1) compounds are believed to be promising objects for prospective studies of superconductivity in one-atom-layer systems.