Gao L, Chen X, Ma Y, Yan Y, Ma T, Su Y, Qiao L. Origin of the moiré superlattice scale lateral force modulation of graphene on a transition metal substrate.
NANOSCALE 2018;
10:10576-10583. [PMID:
29808195 DOI:
10.1039/c8nr01558a]
[Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The moiré superlattice formed between graphene and a transition metal substrate is capable of tuning the frictional properties of graphene. For instance, a moiré superlattice scale modulation on the lateral force will be experienced by the tip of an atomic force microscope (AFM). However, the origin of this long-range force modulation still needs to be clarified. In this study, density functional theory (DFT) calculations have been carried out to investigate the indentation processes of a one-Ar-atom tip and a 10-atom Ir tip, sliding on graphene/Re(0001) and graphene/Pt(111) moiré superlattices, respectively. The calculation results indicate that the interfacial interaction between graphene and a transition metal substrate determines the morphological corrugation of graphene and the characteristics of the lateral force modulation. Moreover, when the tip-graphene interaction is strong enough, it will influence the evolutions of the adsorption energy Ead and tip sliding trajectory. Thus, the moiré superlattice scale lateral force modulation of graphene on a transition metal substrate originates from the joint effects of the graphene-substrate interfacial interaction and tip-graphene interaction.
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