Structural and Dynamical Correlations in Stishovite and High Density Silica Glass

1992 ◽  
Vol 293 ◽  
Author(s):  
Wei Jin ◽  
Rajiv K. Kalia ◽  
Priya Vashishta
Keyword(s):  
Molecular Dynamics ◽  
Density Of States ◽  
Silica Glass ◽  
Bond Angle ◽  
Diffraction Peak ◽  
Static Structure Factor ◽  
Static Structure ◽  
Coordination Numbers ◽  
Intermediate Range Order ◽  
Vibrational Density

AbstractPressure-induced structural transformation from tetrahedral to octahedral coordination and the destruction of intermediate-range order (IRO) are studied in silica glass (a-SiO 2) using the molecular-dynamics (MD) method. Changes in the position and height of the first sharp diffraction peak (FSDP) in the static structure factor, bond lengths, coordination numbers, bond-angle distributions, and statistics of rings are investigated as a function of density. Modifications of the vibrational density of states and participation ratio are also discussed.

Intermediate Range Order in Silicate Melts and Glasses: Computer Simulation Studies

2002 ◽  
Vol 754 ◽  
Author(s):  
Jürgen Horbach ◽  
Anke Winkler ◽  
Walter Kob ◽  
Kurt Binder
Keyword(s):  
Large Scale ◽  
Dynamic Properties ◽  
Range Order ◽  
Silicate Melts ◽  
Main Peak ◽  
Static Structure Factor ◽  
Static Structure ◽  
Intermediate Range ◽  
Intermediate Range Order ◽  
Computer Simulation Studies

ABSTRACTWe present the results of large scale computer simulations to discuss the structural and dynamic properties of silicate melts with the compositions (Na2O)(2·SiO2), (Na2O)(20·SiO2) and (Al2O3)(2·SiO2). We show that these systems exhibit additional intermediate range order as compared to silica (SiO2) where the characteristic intermediate length scales stem from the tetrahedral network structure. Furthermore we show that the sodium dynamics in the sodium silicate systems exhibits a very peculiar feature: the long–time decay of the incoherent intermediate scattering function can be described by a Kohlrausch law with a constant exponent β for q > qth whereby qth is smaller than the location of the main peak in the static structure factor for the Na–Na correlations.

scholarly journals Enhancement of Interfacial Thermal Conductance of SiC by Overlapped Carbon Nanotubes and Intertube Atoms

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Chengcheng Deng ◽  
Xiaoxiang Yu ◽  
Xiaoming Huang ◽  
Nuo Yang
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Silicon Carbide ◽  
Density Of States ◽  
Probability Distributions ◽  
Thermal Conductance ◽  
Nonequilibrium Molecular Dynamics ◽  
Vibrational Density Of States ◽  
Interfacial Thermal Conductance ◽  
Vibrational Density

A new way was proposed to enhance the interfacial thermal conductance (ITC) of silicon carbide (SiC) composite through the overlapped carbon nanotubes (CNTs) and intertube atoms. By nonequilibrium molecular dynamics (NEMD) simulations, the dependence of ITC on both the number of intertube atoms and the temperature was studied. It is indicated that the ITC can be significantly enhanced by adding intertube atoms and finally becomes saturated with the increase of the number of intertube atoms. And the mechanism is discussed by analyzing the probability distributions of atomic forces and vibrational density of states (VDOS). This work may provide some guidance on enhancing the ITC of CNT-based composites.

Amorphous silica from the Rigid Unit Mode approach

2000 ◽  
Vol 64 (3) ◽  
pp. 377-388 ◽  
Author(s):  
M. T. Dove ◽  
K. D. Hammonds ◽  
M. J. Harris ◽  
V. Heine ◽  
D. A. Keen ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Density Of States ◽  
Amorphous Silica ◽  
Energy Cost ◽  
Silica Glass ◽  
Crystalline Phases ◽  
Dynamics Simulations

AbstractWe apply the Rigid Unit Mode model, which was initially developed for crystalline silicates, to the study of the flexibility of silica glass. Using a density-of-states approach we show that silica glass has the same flexibility against infinitesimal displacements of crystalline phases. Molecular dynamics simulations also show that parts of the silica structure are able to undergo large spontaneous changes through reorientations of the SiO4 tetrahedra with no energy cost.

Static Structure Factor of Amorphous Rutile Nanoparticle: A Molecular Dynamics Study

2011 ◽  
Author(s):  
Kulbir Kaur ◽  
Ranber Singh ◽  
Navdeep Goyal ◽  
P. Entel ◽  
Satya Prakash ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Structure Factor ◽  
Static Structure Factor ◽  
Static Structure
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