Lim J, Moon D, Kim S, Kim S. Influence of cutoff radius and tip atomic structure on energy barriers encountered during AFM tip sliding on 2D monolayers.
NANOTECHNOLOGY 2024;
35:40LT01. [PMID:
38986446 DOI:
10.1088/1361-6528/ad6164]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 07/10/2024] [Indexed: 07/12/2024]
Abstract
In computational studies using the Lennard-Jones (LJ) potential, the widely adopted 2.5σcutoff radius effectively truncates pairwise interactions across diverse systems (Santraet al2008J. Chem. Phys.129234704, Chen and Gao 2021Friction9502-12, Bolintineanuet al2014Part. Mech.1321-56, Takahiro and Kazuhiro 2010J. Phys.: Conf. Ser.215012123, Zhouet al2016Fuel180718-26, Toxvaerd and Dyre 2011J. Chem. Phys.134081102, Toxvaerd and Dyre 2011J. Chem. Phys.134081102). Here, we assess its adequacy in determining energy barriers encountered by a Si monoatomic tip sliding on various two-dimensional (2D) monolayers, which is crucial for understanding nanoscale friction. Our findings emphasize the necessity of a cutoff radius of at least 3.5σto achieve energy barrier values exceeding 95% accuracy across all studied 2D monolayers. Specifically, 3.5σcorresponds to 12.70 Å in graphene, 12.99 Å in MoS2and 13.25 Å in MoSe2. The barrier values calculated using this cutoff support previous experiments comparing friction between different orientations of graphene and between graphene and MoS2(Almeidaet al2016Sci. Rep.631569, Zhanget al2014Sci. China57663-7). Furthermore, we demonstrate the applicability of the 3.5σcutoff for graphene on an Au substrate and bilayer graphene. Additionally, we investigate how the atomic configuration of the tip influences the energy barrier, finding a nearly threefold increase in the barrier along the zigzag direction of graphene when using a Si(001) tip composed of seven Si atoms compared to a monoatomic Si tip.
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