Glass-forming ability of the Ni–Zr and Ni–Ti systems determined by interatomic potentials

2001 ◽  
Vol 16 (2) ◽  
pp. 446-450 ◽  
Author(s):  
W. S. Lai ◽  
B. X. Liu
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Solid Solutions ◽  
Relative Stability ◽  
Glass Forming Ability ◽  
Dynamics Simulation ◽  
Interatomic Potentials ◽  
Glass Forming ◽  
Critical Concentrations ◽  
Amorphous States

Employing the n-body potentials of the Ni–Zr and Ni–Ti systems, we performed molecular dynamics simulation to study the relative stability of the terminal solid solutions versus the corresponding amorphous states as a function of solute concentrations. The terminal solid solutions transformed into amorphous states spontaneously when the solute concentrations were beyond the maximum allowable values; i.e., the critical solubilities were determined to be 14 at.% Zr in Ni and 25 at.% Ni in Zr for Ni–Zr system and 38 at.% Ti in Ni and 15 at.% Ni in Ti for the Ni–Ti system. The physical implication of the critical concentrations, as well as their correlation with the glass-forming abilities of the Ni–Zr and Ni–Ti systems, is discussed.

Structural transition and glass-forming ability of the Ni–Hf system studied by molecular dynamics simulation

2004 ◽  
Vol 19 (12) ◽  
pp. 3547-3555 ◽  
Author(s):  
J.H. Li ◽  
L.T. Kong ◽  
B.X. Liu
Keyword(s):  
Molecular Dynamics ◽  
Solid Solution ◽  
Molecular Dynamics Simulation ◽  
Solid Solutions ◽  
Dynamic Properties ◽  
Glass Forming Ability ◽  
Dynamics Simulation ◽  
Face Centered Cubic ◽  
Glass Forming ◽  
Face Centered

A tight-binding Ni–Hf potential is constructed by fitting some of the ground-state properties, such as the cohesive energy, lattice constants, and the elastic constants of some Ni–Hf alloys. The constructed potential is verified to be realistic by reproducing some static and dynamic properties of the system, such as the melting points and thermal expansion coefficients for the pure Ni and Hf as well as some of the equilibrium compounds, through molecular dynamics simulation. Applying the constructed potential, molecular dynamics simulations are performed to compare the relative stability of the face-centered-cubic (fcc)/hexagonal close-packed (hcp) solid solutions to their disordered counterparts as a function of solute concentration. It is found that the solid solutions become unstable and transform into the disordered states spontaneously, when the solute concentrations exceed the two critical solid solubilities, i.e., 25 at.% Ni for hcp Hf-rich solid solution and 18 at.% Hf for fcc Ni-based solid solution, respectively. This allows us to determine that the glass-forming ability/range of the Ni–Hf system is within 25–82 at.% Ni. Interestingly, simulations also reveal for the first time, that two mixed regions exist in which an amorphous phase coexists with a crystalline phase, and at about 18 at.% Ni, the hcp lattice turns into a new metastable phase identified to be face-centered orthorhombic structure.

scholarly journals Comparative Studies on Water Self-Diffusivity Confined in Graphene Nanogap: Molecular Dynamics Simulation

2016 ◽  
Author(s):  
Mohammad Moulod ◽  
Gisuk Hwang
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Surface Energy ◽  
Water Transport ◽  
Surface Interactions ◽  
Bulk Water ◽  
Water Desalination ◽  
Atomic Scale ◽  
Dynamics Simulation ◽  
Interatomic Potentials

Fundamental understanding of the water in graphene is crucial to optimally design and operate the sustainable energy, water desalination, and bio-medical systems. A numerous atomic-scale studies have been reported, primarily articulating the surface interactions (interatomic potentials) between the water and graphene. However, a systematic comparative study among the various interatomic potentials is rare, especially for the water transport confined in the graphene nanostructure. In this study, the effects of different interatomic potentials and gap sizes on water self-diffusivity are investigated using the molecular dynamics simulation at T = 300 K. The water is confined in the rigid graphene nanogap with the various gap sizes Lz = 0.7 to 4.17 nm, using SPC/E and TIP3P water models. The water self-diffusivity is calculated using the mean squared displacement approach. It is found that the water self-diffusivity in the confined region is lower than that of the bulk water, and it decreases as the gap size decreases and the surface energy increases. Also, the water self-diffusivity nearly linearly decreases with the increasing surface energy to reach the bulk water self-diffusivity at zero surface energy. The obtained results provide a roadmap to fundamentally understand the water transport properties in the graphene geometries and surface interactions.

Machine Learning Interatomic Potentials for Global Optimization and Molecular Dynamics Simulation

2019 ◽  
pp. 253-288 ◽  
Author(s):  
Ivan A. Kruglov ◽  
Pavel E. Dolgirev ◽  
Artem R. Oganov ◽  
Arslan B. Mazitov ◽  
Sergey N. Pozdnyakov ◽  
...  
Keyword(s):  
Machine Learning ◽  
Molecular Dynamics ◽  
Global Optimization ◽  
Molecular Dynamics Simulation ◽  
Dynamics Simulation ◽  
Interatomic Potentials
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