Reconstruction of a 2D layer of KBr on Ir(111) and electromechanical alteration by graphene

Beilstein Journal of Nanotechnology

article

Zhao Liu¹  Antoine Hinaut¹  Stefan Peeters²  Sebastian Scherb¹  Ernst Meyer¹  Maria Clelia Righi²  Thilo Glatzel¹ 

[1] Department of Physics, University of Basel;Department of Physics and Astronomy, University of Bologna

关键词: DFT;    graphene;    Ir(111);    KBr;    KPFM;    nc-AFM;    surface reconstruction;   

DOI  :  10.3762/bjnano.12.35

学科分类：环境监测和分析

来源: Beilstein - Institut zur Foerderung der Chemischen Wissenschaften

【 摘 要 】

A novel reconstruction of a two-dimensional layer of KBr on an Ir(111) surface is observed by high-resolution noncontact atomicforce microscopy and verified by density functional theory (DFT). The observed KBr structure is oriented along the main directions of the Ir(111) surface, but forms a characteristic double-line pattern. Comprehensive calculations by DFT, taking into accountthe observed periodicities, resulted in a new low-energy reconstruction. However, it is fully relaxed into a common cubic structurewhen a monolayer of graphene is located between substrate and KBr. By using Kelvin probe force microscopy, the work functionsof the reconstructed and the cubic configuration of KBr were measured and indicate, in accordance with the DFT calculations, adifference of nearly 900 meV. The difference is due to the strong interaction and local charge displacement of the K+/Br− ions andthe Ir(111) surface, which are reduced by the decoupling effect of graphene, thus yielding different electrical and mechanical properties of the top KBr layer.

【 授权许可】

CC BY