Molecular Dynamics Simulations of Melting Iron Nanoparticles with/without Defects Using a Reaxff Reactive Force Field

Sun, Junlei; Liu, Pingan; Wang, Mengjun

doi:10.1038/s41598-020-60416-5

Cited by 23 publications

(15 citation statements)

References 32 publications

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“…In other words, it could be used to quantify the structural order. Upon solid–liquid phase transition, peaks essentially decrease and widen indicating the loss of an ordered lattice which does not happen in the B 4 As 2 sheet even at 800 K (Figure g). Apparently, a temperature increase also causes broadening and lowering of the peaks.…”

Section: Resultsmentioning

confidence: 99%

Band Gap Engineering and 14 Electron Superatoms in 2D Superoctahedral Boranes B₄X₂ (B, N, P, As, Sb)

et al. 2021

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Band gap tuning in 2D monolayers is one of the most attractive approaches in design and production of new atomically thin semiconductors. Following our recent computational design of stable two-dimensional octahedral boranes, we present comprehensive computational study of electronic structure, stability and properties of members belonging to family B4X2 (X = B, N, P, As, Sb). We select 15 group atoms (pnictogens) as apical substituents to stabilize quasi-octahedral units by delocalized bonding and create interlayer “pressure” caused by vertically aligned lone pairs. We first substitute apical B atoms by N and then go down the 15 group to capture electronic structure trends. B→N substitution opens band gap, while further substitution consistently narrows band gap. We revealed elegant band gap trend which is inversely proportional to the size of octahedral units. Thus, old as world isoelectronic substitution could be used for band gap engineering in superoctahedral 2D boranes and other monolayers. We also discovered superatomic bonding in B4As2 and B4P2 octahedra which agrees with their exceptional stability (up to 800 K) and magnetic response properties. Remarkably, both B4As2 and B4P2 units have 14 valence electrons, making them exceptional examples of stable nonconventional electron count of spherical aromaticity. Alongside with a considerable negative formation energy and phonon stability, B4As2 has extremely low exfoliation energy of 0.02 eV/atom implying probability of synthetic route from a putative bulk material. It gives a strong basis to believe in possibility of experimental fabrication of B4As2 monolayer which can serve as alternative to MoS2 and silicon.

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Section: Resultsmentioning

confidence: 99%

Band Gap Engineering and 14 Electron Superatoms in 2D Superoctahedral Boranes B₄X₂ (B, N, P, As, Sb)

et al. 2021

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“…It should be mentioned that the heating rate influences thermodynamic outcomes [ 41 ]; therefore, initially two different heating rates (25 K/20 ns and 50 K/20 ns) were tested to observe the reproducibility of calculated T m .…”

Section: Methodsmentioning

confidence: 99%

A Molecular Dynamics Study of Cyanate Ester Monomer Melt Properties

et al. 2022

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The objective of this work was to computationally predict the melting temperature and melt properties of thermosetting monomers used in aerospace applications. In this study, we applied an existing voids method by Solca. to examine four cyanate ester monomers with a wide range of melting temperatures. Voids were introduced into some simulations by removal of molecules from lattice positions to lower the free-energy barrier to melting to directly simulate the transition from a stable crystal to amorphous solid and capture the melting temperature. We validated model predictions by comparing melting temperature against previously reported literature values. Additionally, the torsion and orientational order parameters were used to examine the monomers’ freedom of motion to investigate structure–property relationships. Ultimately, the voids method provided reasonable estimates of melting temperature while the torsion and order parameter analysis provided insight into sources of the differing melt properties between the thermosetting monomers. As a whole, the results shed light on how freedom of molecular motions in the monomer melt state may affect melting temperature and can be utilized to inspire the development of thermosetting monomers with optimal monomer melt properties for demanding applications.

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“…At the last 10,000 timesteps, we took an average of the total energy and potential energy of the system. When the potential energy plot through temperature presents a gap, the corresponding temperature (

—limit of superheating) is used to determine the material’s melting point (

) as [ 24 ]:

…”

Section: Methodsmentioning

confidence: 99%

Employing Hybrid Lennard-Jones and Axilrod-Teller Potentials to Parametrize Force Fields for the Simulation of Materials’ Properties

Branco

Cheng

2021

Materials

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The development of novel materials has challenges besides their synthesis. Materials such as novel MXenes are difficult to probe experimentally due to their reduced size and low stability under ambient conditions. Quantum mechanics and molecular dynamics simulations have been valuable options for material properties determination. However, computational materials scientists may still have difficulty finding specific force field models for their simulations. Force fields are usually hard to parametrize, and their parameters’ determination is computationally expensive. We show the Lennard-Jones (2-body interactions) combined with the Axilrod-Teller (3-body interactions) parametrization process’ applicability for metals and new classes of materials (MXenes). Because this parametrization process is simple and computationally inexpensive, it allows users to predict materials’ behaviors under close-to-ambient conditions in molecular dynamics, independent of pre-existing potential files. Using the process described in this work, we have made the Ti2C parameters set available for the first time in a peer-reviewed work.

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Molecular Dynamics Simulations of Melting Iron Nanoparticles with/without Defects Using a Reaxff Reactive Force Field

Cited by 23 publications

References 32 publications

Band Gap Engineering and 14 Electron Superatoms in 2D Superoctahedral Boranes B₄X₂ (B, N, P, As, Sb)

Band Gap Engineering and 14 Electron Superatoms in 2D Superoctahedral Boranes B₄X₂ (B, N, P, As, Sb)

A Molecular Dynamics Study of Cyanate Ester Monomer Melt Properties

Employing Hybrid Lennard-Jones and Axilrod-Teller Potentials to Parametrize Force Fields for the Simulation of Materials’ Properties

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Molecular Dynamics Simulations of Melting Iron Nanoparticles with/without Defects Using a Reaxff Reactive Force Field

Cited by 23 publications

References 32 publications

Band Gap Engineering and 14 Electron Superatoms in 2D Superoctahedral Boranes B4X2 (B, N, P, As, Sb)

Band Gap Engineering and 14 Electron Superatoms in 2D Superoctahedral Boranes B4X2 (B, N, P, As, Sb)

A Molecular Dynamics Study of Cyanate Ester Monomer Melt Properties

Employing Hybrid Lennard-Jones and Axilrod-Teller Potentials to Parametrize Force Fields for the Simulation of Materials’ Properties

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Band Gap Engineering and 14 Electron Superatoms in 2D Superoctahedral Boranes B₄X₂ (B, N, P, As, Sb)

Band Gap Engineering and 14 Electron Superatoms in 2D Superoctahedral Boranes B₄X₂ (B, N, P, As, Sb)