Effects of a graphene substrate on the structure and properties of atomically thin metal sheets

摘要

The production and use of atomically thin metal sheets are desirable but challenging. Here, density functional theory calculations indicate that the introduction of graphene as a support can play an unexpected role in the stability and function of Rh monolayer, as a representative of single-layer metal nanosheets. The graphene stabilizes the otherwise unstable Rh monolayer by the substrate interaction that not only impedes the out-of-plane movement of the Rh atoms but also decreases the surface energy. The Rh/graphene bilayer has good mechanical properties, comparable to those of emerging 2D graphene-based materials. The interfacial stress from the substrate interaction causes surface corrugations to form on the bilayer, exhibiting a degree of consistency in the direction and the area. Discrete magnetic units, compatible with the substrate interaction, are present in the corrugated Rh sheet. The visible magnetic anisotropy and spin-splitting of polarized carrier states of the corrugated Rh sheet dominate the spin-dependent transport in the bilayer film, which can be used as a building block for ultrathin electronic/spintronic devices.