ReaxFF Reactive Force-Field Study of Molybdenum Disulfide (MoS₂)

Abstract

Two-dimensional layers of molybdenum disulfide, MoS, have been recognized as promising materials for nanoelectronics due to their exceptional electronic and optical properties. Here we develop a new ReaxFF reactive potential that can accurately describe the thermodynamic and structural properties of MoS sheets, guided by extensive density functional theory simulations. This potential is then applied to the formation energies of five different types of vacancies, various vacancy migration barriers, and the transition barrier between the semiconducting 2H and metallic 1T phases. The energetics of ripplocations, a recently observed defect in van der Waals layers, is examined, and the interplay between these defects and sulfur vacancies is studied. As strain engineering of MoS sheets is an effective way to manipulate the sheets' electronic and optical properties, the new ReaxFF description can provide valuable insights into morphological changes that occur under various loading conditions and defect distributions, thus allowing one to tailor the electronic properties of these 2D crystals.

Strain‐Induced Structural Deformation Study of 2D MoxW(1‐x) S2

“…It is important to stress that the MD and DFT results agree only qualitatively due to the parameterization used for the Stillinger-Weber potential and methods utilized for the DFT calculations, however both calculations agree with literature [40,42,43] results were Mo-S and W-S bonds ranges between 2.38 and 2.46 Å. Consequently, the metal-metal distances would be affected as well. It is important to stress that the MD and DFT results agree only qualitatively due to the parameterization used for the Stillinger-Weber potential and methods utilized for the DFT calculations, however both calculations agree with literature [40,42,43] results were Mo-S and W-S bonds ranges between 2.38 and 2.46 Å. Consequently, the metal-metal distances would be affected as well.…”

“…Mo-Mo distances of the remaining atoms. It is important to stress that the MD and DFT results agree only qualitatively due to the parameterization used for the Stillinger-Weber potential and methods utilized for the DFT calculations, however both calculations agree with literature [40,42,43] results were Mo-S and W-S bonds ranges between 2.38 and 2.46 Å. Consequently, the metal-metal distances would be affected as well.…”

Hydrogenation and defect formation control the strength and ductility of MoS2 nanosheets: Reactive molecular dynamics simulation

“…ReaxFF potentials have been applied to a wide range of systems, which allows the reactivity and describing the bond formation and breakage as well [59][60][61][62] . As discussed in our previous studies, the proposed ReaxFF by Ostadhossein et al 58 yields accurate predictions for the mechanical properties 24 and thermal conductivity 63 of defect-free MoS 2 . For the evaluating the mechanical properties, we constructed an original atomistic model of pristine 2H-MoS 2 including 8280 individual atoms in a simulation box size with planar dimensions of 25 nm × 9.5 nm.…”

Advances in nonequilibrium molecular dynamics simulations of lubricants and additives

“…The generation of high-quality parameter sets is a very difficult and time consuming task due to the huge number of parameters which need to be fitted [281]. Despite this, ReaxFF parameters have been developed which can be used to investigate some important lubricant and additive molecules, such as alkanes and alcohols [282,283], phosphoric acids [284], organosulphur compounds [285], and molybdenum disulphide [286]. Using such force-fields, relatively large molecular systems (nm) can be compressed and sheared [284] in a similar manner to conventional confined NEMD simulations ( Fig.…”