Molecular dynamics simulation of structural transformation in SiO2 glass under densification

In bimetallic cluster, research on the frozen structure with the changing concentration plays an important role in exploring new structural materials. This paper studies the freezing processes of (AgCu)309clusters with different Ag concentrations. The results indicated that the structural transformation was strongly related to concentration. It was found that the frozen structures were changed form icosahedron, hcp and fcc-hcp with the change of Ag concentration. The frozen structures were formed icosahedral for the clusters with Ag concentration at 10%, 20%, 30%, and the pure Ag309. For the clusters with Ag content at 40%, 50%, 60%, 70%, and 80%, the frozen structures were formed defect icosahedral. It was also found that the frozen structure have hcp character for the pure Cu309cluster. Meanwhile, the frozen structure of (AgCu)309with 90% Ag concentration was formed fcc-hcp structure. The segregation effects of the Ag-Cu are the key reason for the structural transformation.

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Molecular Dynamics Simulation of Structural Transformation in Silicon Carbide under Pressure

Physical Review Letters ◽

10.1103/physrevlett.84.3338 ◽

2000 ◽

Vol 84 (15) ◽

pp. 3338-3341 ◽

Cited By ~ 144

Author(s):

Fuyuki Shimojo ◽

Ingvar Ebbsjö ◽

Rajiv K. Kalia ◽

Aiichiro Nakano ◽

Jose P. Rino ◽

...

Keyword(s):

Molecular Dynamics ◽

Silicon Carbide ◽

Molecular Dynamics Simulation ◽

Structural Transformation ◽

Dynamics Simulation

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Reproduction of Pressure-Induced Structural Transformation of α-Quartz-Type GeO2 by Molecular Dynamics Simulation

Journal of the Ceramic Society of Japan ◽

10.2109/jcersj.104.1097 ◽

1996 ◽

Vol 104 (1216) ◽

pp. 1097-1099 ◽

Cited By ~ 2

Author(s):

Dae-Weon KIM ◽

Katsuyuki KAWAMURA ◽

Naoya ENOMOTO ◽

Zenbe-e NAKAGAWA

Keyword(s):

Molecular Dynamics ◽

Molecular Dynamics Simulation ◽

Structural Transformation ◽

Dynamics Simulation

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Molecular Structural Transformation of 2:1 Clay Minerals by a Constant-Pressure Molecular Dynamics Simulation Method

Journal of Nanomaterials ◽

10.1155/2010/795174 ◽

2010 ◽

Vol 2010 ◽

pp. 1-13

Author(s):

Jianfeng Wang ◽

Marte S. Gutierrez

Keyword(s):

Molecular Dynamics ◽

Molecular Dynamics Simulation ◽

Cell Size ◽

Clay Minerals ◽

Structural Transformation ◽

Constant Pressure ◽

Shape Change ◽

Interlayer Spacing ◽

Dynamics Simulation ◽

Size And Shape

This paper presents results of a molecular dynamics simulation study of dehydrated 2:1 clay minerals using the Parrinello-Rahman constant-pressure molecular dynamics method. The method is capable of simulating a system under the most general applied stress conditions by considering the changes of MD cell size and shape. Given the advantage of the method, it is the major goal of the paper to investigate the influence of imposed cell boundary conditions on the molecular structural transformation of 2:1 clay minerals under different normal pressures. Simulation results show that the degrees of freedom of the simulation cell (i.e., whether the cell size or shape change is allowed) determines the final equilibrated crystal structure of clay minerals. Both the MD method and the static method have successfully revealed unforeseen structural transformations of clay minerals upon relaxation under different normal pressures. It is found that large shear distortions of clay minerals occur when full allowance is given to the cell size and shape change. A complete elimination of the interlayer spacing is observed in a static simulation. However, when only the cell size change is allowed, interlayer spacing is retained, but large internal shear stresses also exist.

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