Influence of line defects on relaxation properties of graphene: A molecular dynamics study

We analyze the tumbling motion of a solvated paramagnetic complex close to confining particles. Molecular dynamics data is interpreted via mechanistic modeling, towards design of improved nanovectors for local enhancement of relaxation properties.

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Molecular dynamics study on the relaxation properties of bilayered graphene with defects

Bulletin of Materials Science ◽

10.1007/s12034-017-1452-7 ◽

2017 ◽

Vol 40 (6) ◽

pp. 1255-1261

Author(s):

Wei Zhang ◽

Jiu-Ren Yin ◽

Ping Zhang ◽

Yan-Huai Ding ◽

Yong Jiang

Keyword(s):

Molecular Dynamics ◽

Relaxation Properties

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Molecular Dynamics Studies of the Melting of Copper with Vacancies amd Dislocations at High Pressures

MRS Advances ◽

10.1557/adv.2017.353 ◽

2017 ◽

Vol 2 (48) ◽

pp. 2597-2602 ◽

Cited By ~ 1

Author(s):

Clarence C Matthai ◽

Jessica Rainbow

Keyword(s):

Molecular Dynamics ◽

Melting Temperature ◽

Large Scale ◽

High Pressures ◽

Defect Density ◽

Melting Process ◽

Interatomic Potentials ◽

Embedded Atom ◽

Line Defects ◽

Dynamics Simulations

ABSTRACTMolecular dynamics simulations of the melting process of bulk copper were performed using the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) with the interatomic potentials being described by the embedded atom method. The aim of the study was to understand the effects of high pressures and defects on the melting temperature. The simulations were visualised using Visual Molecular Dynamics (VMD). The melting temperature of a perfect copper crystal, was found to be slightly higher than the experimentally observed value. The melting temperature as a function of pressure was determined and compared with experiment. Point and line defects, in the form of dislocations, were then introduced into crystal and the new melting temperature of the crystal determined. We find that the melting temperature decreases as the defect density is increased. Additionally, the slope of the melting temperature curve was found to decrease as the pressure was increased while the vacancy formation energy increases with pressure.

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Relaxation properties of graphene nanoribbons at different ambient temperatures: a molecular dynamics study

Acta Physica Sinica ◽

10.7498/aps.61.200207 ◽

2012 ◽

Vol 61 (20) ◽

pp. 200207

Author(s):

Wang Wei-Dong ◽

Hao Yue ◽

Ji Xiang ◽

Yi Cheng-Long ◽

Niu Xiang-Yu

Keyword(s):

Molecular Dynamics ◽

Graphene Nanoribbons ◽

Relaxation Properties ◽

Ambient Temperatures

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Thickness Induced Line-Defect Reconfigurations in Thin Nematic Cell

Advances in Condensed Matter Physics ◽

10.1155/2019/4256526 ◽

2019 ◽

Vol 2019 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

M. Ambrožič ◽

S. Kralj

Keyword(s):

Molecular Dynamics ◽

Boundary Conditions ◽

Strong Impact ◽

Line Defect ◽

History Of ◽

Line Defects ◽

The Impact ◽

Surface Fields ◽

Threshold Regime ◽

Cell Thickness

We studied the impact of the cell thickness on configurations of line disclinations within a plane-parallel nematic cell. The Lebwohl-Lasher semimicroscopic approach was used and (meta)stable nematic configurations were calculated using Brownian molecular dynamics. Defect patterns were enforced topologically via boundary conditions. We imposed periodic circular nematic surface fields at each confining surface. The resulting structures exhibit line defects which either connect the facing plates or remain confined within the layers near confining plates. The first structure is stable in relatively thin cells and the latter one in thick cells. We focused on structures at the threshold regime where both structures compete. We demonstrated that “history” of samples could have strong impact on resulting nematic configurations.

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Disconnection description of triple-junction motion

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1820789116 ◽

2019 ◽

Vol 116 (18) ◽

pp. 8756-8765 ◽

Cited By ~ 10

Author(s):

Spencer L. Thomas ◽

Chaozhen Wei ◽

Jian Han ◽

Yang Xiang ◽

David J. Srolovitz

Keyword(s):

Molecular Dynamics ◽

Microstructure Evolution ◽

Md Simulation ◽

Polycrystalline Materials ◽

Triple Junctions ◽

Continuum Approach ◽

Physically Based ◽

Line Defects ◽

Simulation Results ◽

The Continuum

Grain boundary (GB) migration in polycrystalline materials necessarily implies the concurrent motion of triple junctions (TJs), the lines along which three GBs meet. Today, we understand that GB migration occurs through the motion of disconnections in the GB plane (line defects with both step and dislocation character). We present evidence from molecular dynamics grain growth simulations and idealized microstructures that demonstrates that TJ motion and GB migration are coupled through disconnection dynamics. Based on these results, we develop a theory of coupled GB/TJ migration and use it to develop a physically based, disconnection mechanism-specific continuum model of microstructure evolution. The continuum approach provides a means of reducing the complexity of the discrete disconnection picture to extract the features of disconnection dynamics that are important for microstructure evolution. We implement this model in a numerical, continuum simulation and demonstrate that it is capable of reproducing the molecular dynamics (MD) simulation results.

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