Atomistic simulations of nanoindentation on the basal plane of crystalline molybdenum disulfide (MoS₂)

Abstract

In the present work, nanoindentation on the basal surface of a crystalline molybdenum disulfide (MoS2) thin film is investigated by molecular statics (MS) calculations. A previously parameterized interatomic potential combining the reactive empirical bond-order and Lennard-Jones potentials is implemented into the LAMMPS molecular simulation package and refined for improved prediction of the mechanical properties of MoS2 at athermal conditions. Nanoindentation simulations are performed using three indenter sizes with specific focus on the incipient plastic deformation event within the MoS2single crystal. MS calculations show that a local phase transformation occurs beneath the indenter at plastic yield without the presence of broken Mo–S bonds. The structural characteristics of the phase transformation are captured using a slip vector analysis. The nanoindentation simulations provide insight into the mechanical response of MoS2 during contact deformation characteristic of both synthesis and application for better design of MoS2 nanoparticle lubricants.

Chemically exfoliated MoS2 for capacitive deionization of saline water

“…[31] Atomic force microscope (AFM) measurements show an average thicknesses from 2.2 to 2.6 nm (Figures 2e-f), which is consistent with reported values of ce-MoS 2 . [38,39] Electrosorption desalination performances of the as-prepared 1T-MoS 2 nanosheets were tested by cyclic voltammetry (CV) measurements with a conventional three-electrode cell.…”

“…[30] The interlayer spacing was calculated as ~0.65 nm according to the (002) reflection, which is much larger than that of the corresponding bulk phase and is helpful for ion intercalation and adsorption. [31] Raman spectroscopy shows that the shoulder of A 1 g peak shifts from 406.4 cm −1 to 403 cm −1 ; and E 1 2g shifts from 380.9 cm −1 to 381.6 cm −1 (Figure 1b). Theoretically, only E 1 2g and A 1 g peaks are strongly influenced by the thicknesses of MoS 2 flakes, while the blue-shift of A 1 g mode and red-shift of E 1 2g mode E 1 2g are related with the change of layer number.…”

Nanomechanical cleavage of molybdenum disulphide atomic layers

“…The Mo-S potential was parameterized to match density functional theory calculations of Mo, S and Mo-S structures 43 . The parameterization was successfully applied in the investigation of the mechanical properties of crystalline MoS 2 by the indentation method 44 and in the studies of behaviour of MoS 2 multilayered nanotubes in extreme pressure conditions 45 . This technique is perfect to describe structural and mechanical properties of the Mo-S systems consisting of a large number of atoms (410 4 ).…”

Graphene versus MoS2: A short review

“…In 2009, Liang et al parametrized a bond-order potential for SLMoS 2 [38], which was based on the bond-order concept underlying the Brenner potential [33]. This Brenner-like potential was further modified to study the nanoindentations in SLMoS 2 thin films using a molecular statics approach [39]. Recently, we parametrized the SW potential for SLMoS 2 , where the potential parameters were fitted to the phonon spectrum [28].…”