Self-texturizing electronic properties of a 2-dimensional GdAu2 layer on Au(111): the role of out-of-plane atomic displacement

Abstract

Tuning the electronic properties of two-dimensional (2D) layers is a current focus of interdisciplinary research. Here, we show that the electronic properties of a surface- supported 2-dimensional (2D) layer structure can spontaneously self-texturize at nanoscale. Specifically, we have characterized the 2D layer GdAu2 forming a mismatched interface on Au(111). We demonstrate that the variable adsorption stacking configurations causes local structural relaxation processes which result in a spatially modulated layer-buckling. This is sufficient to periodically open, at the Fermi level, an energy gap of ~0.5 eV at well-defined stacking configurations on an otherwise metallic layer. Additionally, this out-of-plane displacement of the Gd atoms patterns the character of the hybridized Gd-d states and shifts the center of mass of the Gd 4f multiplet proportionally to the lattice distortion. These findings demonstrate the close correlation between the electronic properties of the 2D-layer and its planarity. We demonstrate that the resulting template shows different chemical reactivity which may find important applications. We will compare the properties of the 2D-layer of GdAu2/Au(111) with the previously reported GdAg2/Ag(111).